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  • 1.
    Abdul Qadhr, Göran
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Molin, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Suurküla, Madis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Hagberg, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Whole-body diffusion-weighted imaging compared with FDG-PET/CT in staging of lymphoma patients2011In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, no 2, p. 173-180Article in journal (Refereed)
    Abstract [en]

    Background:

    Diffusion-weighted imaging (DWI) has become increasingly valuable in lymph node imaging, yet the clinical utility of this technique in the staging of lymphoma has not been established.

    Purpose:

    To compare whole-body DWI with FDG-PET/CT in the staging of lymphoma patients.

    Material and Methods:

    Thirty-one patients, eight with Hodgkin lymphoma (HL) and 23 with non-Hodgkin's lymphoma (18 aggressive and five indolent) underwent both whole-body DWI, whole-body MRI (T1W and T2W-STIR) and FDG-PET/CT. Lesions on whole-body DWI were only considered positive if they correlated with lesions on T1W and T2W-STIR images. The staging given by each technique was compared, according to the Ann Arbor staging system. Differences in staging were solved using biopsy results, and clinical and CT follow-ups as standard of reference.

    Results:

    The staging was the same for DWI and FDG-PET/CT in 28 (90.3%) patients and different in three (9.7%). Of the 28 patients with the same staging, 11 had stage IV in both techniques and 17 had stages 0-III. No HL or aggressive non-Hodgkin's lymphoma patients had different staging. Three indolent small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) lymphoma had higher staging with DWI when compared with FDG-PET/CT. One small subcutaneous breast lymphoma was not seen but all other extranodal sites were detected by both techniques.

    Conclusion:

    Whole-body DWI is a promising technique for staging of both (aggressive and indolent) non-Hodgkin's lymphoma and HL.

  • 2.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ladjevardi, Sam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Brekkan, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Häggman, Michael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wernroth, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular epidemiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors:: A modified R.E.N.A.L nephrometry score adjusted comparison.2018In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, no 2, p. 260-268Article in journal (Refereed)
    Abstract [en]

    Background: Comparable oncological outcomes have been seen after surgical nephrectomy and thermal ablation of renal tumors recently. However, periprocedural outcome needs to be assessed for aiding treatment decision.

    Purpose: To compare efficacy rates and periprocedural outcome (technical success, session time, hospitalization time, and complications) after renal tumor treatment with laparoscopic partial nephrectomy (LPN) or radiofrequency ablation (RFA).

    Material and Methods: The initial experience with 49 (treated with LPN) and 84 (treated with RFA) consecutive patients for a single renal tumor (diameter ≤ 5 cm, limited to the kidney) during 2007-2014 was evaluated. Patient and tumor characteristics, efficacy rates, and periprocedural outcome were collected retrospectively. The stratified Mantel Haenzel and Van Elteren tests, adjusted for tumor complexity (with the modified R.E.N.A.L nephrometry score [m-RNS]), were used to assess differences in treatment outcomes.

    Results: Primary efficacy rate was 98% for LPN and 85.7% for RFA; secondary efficacy rate was 93.9% for LPN and 95.2% for RFA; and technical success rate was 87.8% for LPN and 100% for RFA. Median session (m-RNS adjusted P < 0.001; LPN 215 min, RFA 137 min) and median hospitalization time were longer after LPN (m-RNS adjusted P < 0.001; LPN 5 days, RFA 2 days). Side effects were uncommon (LPN 2%, RFA 4.8%). Complications were more frequent after LPN (m-RNS adjusted P < 0.001; LPN 42.9%, RFA 10.7%).

    Conclusion: Both methods achieved equivalent secondary efficacy rates. RFA included several treatment sessions, but session and hospitalization times were shorter, and complications were less frequent than for LPN. The differences remained after adjustment for renal tumor complexity.

  • 3.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Brekkan, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wernroth, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular epidemiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Predictive factors for complete renal tumor ablation using RFA2016In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 7, p. 886-893Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

    PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

    MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

    RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

    CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

  • 4.
    Ahlström, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Gehl, H B
    Overview of MnDPDP as a pancreas-specific contrast agent for MR imaging1997In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, no 4 Pt 2, p. 660-664Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To describe and discuss previous and ongoing clinical and experimental studies with MnDPDP (Teslascan) as a pancreas-specific contrast agent for MR imaging.

    MATERIAL AND METHODS:

    All results, both experimental and clinical, applying MnDPDP as a pancreas-specific contrast agent for MR imaging, were collected.

    RESULTS:

    An increase of up to 100% in signal intensity was seen in normal pancreatic parenchyma, reaching its maximum approximately 25 min after the beginning of MnDPDP administration. Maximal enhancement was sustained for 4 h. Enhancement was only seen in the T1-weighted images. No enhancement was observed in tumours and an increase in contrast-to-noise of about 200% was obtained. The uptake of MnDPDP in pancreatitis compared with normal pancreatic parenchyma was decreased in an animal model.

    CONCLUSION:

    Improved depiction and demarcation of pancreatic tumours with MR imaging were obtained after administration of MnDPDP. MR imaging with and without MnDPDP might be valuable for staging of pancreatitis.

  • 5.
    Ahlström, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Grama, D
    Eriksson, Barbro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Öberg, Kjell
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lörelius, L-E
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Preoperative localization of endocrine pancreatic tumours by intra-arterial dynamic computed tomography1990In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 31, no 2, p. 171-175Article in journal (Refereed)
    Abstract [en]

    Eleven patients with biochemically confirmed endocrine pancreatic tumours were examined with intra-arterial (i.a.) dynamic computed tomography (CT) and angiography preoperatively. Seven of the patients suffered from the multiple endocrine neoplasia type 1 (MEN-1) syndrome. All patients were operated upon and surgical palpation and ultrasound were the peroperative localization methods. Of the 33 tumours which were found at histopathologic analysis of the resected specimens in the 11 patients, 7 tumours in 7 patients were correctly localized by both i.a. dynamic CT and angiography. Six patients with MEN-1 syndrome had multiple tumours and this group of patients together had 28 tumours, of which 5 (18%) were localized preoperatively by both CT and angiography. I.a. dynamic CT, with the technique used by us, does not seem to improve the localization of endocrine pancreatic tumours, especially in the rare group of MEN-1 patients, as compared with angiography.

  • 6.
    Ahlström, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Malmström, Per-Uno
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Letocha, H
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Andersson, J
    Institutionen för läkemedelskemi; Plattformen för preklinisk PET, Uppsala university, Uppsala.
    Långström, Bengt
    Institutionen för läkemedelskemi; Plattformen för preklinisk PET, Uppsala university, Uppsala.
    Nilsson, S
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Positron emission tomography in the diagnosis and staging of urinary bladder cancer1996In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 37, no 2, p. 180-185Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    Evaluation of positron emission tomography (PET) using (18)fl 18F-2-fluoro-2-deoxy-D-glucose (18FDG) and L-methyl-11C-methionine in the diagnosis and staging of urinary bladder carcinoma.

    MATERIAL AND METHODS:

    Twenty-three patients with biopsy-proven urinary bladder carcinoma were examined with PET after intravenous injection of 11C-methionine; 2 were also examined with 18FDG. The results from the PET investigations were compared with CT or MR findings and TNM classification before and after treatment.

    RESULTS:

    The urinary excretion of 18FDG prevented distinction of the primary tumour from the surrounding tracer. With 11C-methionine it was possible to detect 18/23 primary tumours. A trend was seen, suggesting that the higher the uptake values of 11C-methionine in the tumour, the greater the tumour stage.

    CONCLUSION:

    It is possible to visualize urinary bladder tumours larger than 1 cm in diameter with PET using (11)C-methionine, but the value of the method in the staging of the lesions is not superior to conventional methods.

  • 7.
    Alemany Ripoll, Montserrat
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Gustafsson, O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Siösteen, B.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Olsson, Y.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    MR follow-up of small experimental intracranial haemorrhages from hyperacute to subacute phase2002In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, no 1, p. 2-9Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To compare pulse sequences in revealing intracranial bleeding from the hyperacute to subacute phase. MATERIAL AND METHODS: We injected 0.3-1 ml of autologous blood into the brain of 8 rabbits. MR imaging was performed immediately after haematoma creation and then at determined intervals up to 9-12 days. All images were analysed by two observers. After the last MR investigation, the brain was fixed in formalin. The last MR images were compared to the fixed brain sections and to the histologic findings. RESULTS: T2*-weighted GE sequences, both conventional spoiled and echoplanar sequences, revealed the intraparenchymal haematomas as hypointensities in all but 1 case, which was negative from the second day onward (a rabbit with 0.3 ml blood injected). The signal patterns remained unchanged during the follow-up. The haematoma sizes and shapes corresponded well to gross pathology. Blood in the cerebrospinal fluid (CSF) space was detected with T2*-weighted GE sequences in a great majority of the examinations during the first 2 days. The cases with the smallest injected volume of blood were negative. SE sequences were rather insensitive. The FLAIR sequence often revealed blood in CSF spaces but not in the brain. CONCLUSION: T2*-weighted GE sequences are capable of revealing very small intraparenchymal haemorrhages from the hyperacute to the subacute phase, and blood in CSF spaces during at least the first 2 days.

  • 8.
    Alemany Ripoll, Montserrat
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Experimental intracerebral and subarachnoid/intraventricular haemorrhages2002In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, no 5, p. 464-73Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. MATERIAL AND METHODS: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. RESULTS: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90-95% at 0.5 T. Blood in the CSF spaces was significantly (p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. CONCLUSION: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.

  • 9.
    Bjerner, Tomas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Haglund, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Upper Abdominal Surgery.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    3D surface rendering of images from multiple MR pulse sequences in the pre-operative evaluation of hepatic lesions1998In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, no 6, p. 698-700Article in journal (Refereed)
    Abstract [en]

    Segmentation and reconstruction took 1-2 h. To be able to combine the volumes from the different data sets, certain criteria had to be fulfilled: a) the field of view had to be constant; b) the same volume had to be scanned every time which meant that the slice thickness and the number of slices could be adjusted as long as the volume covered was the same; and c) the positioning of each volume had to be identical between every scan. The resulting 3D reconstruction gave the surgeon a clear appreciation of the different lesions and their relation to the different liver segments in the pre-operative planning of hepatic resections.

  • 10.
    Björkman, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Eklöf, Hampus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Wadström, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Andersson, L-G.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Split renal function in patients with suspected renal artery stenosis: a comparison between gamma camera renography and two methods of measurements with computed tomography2006In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, no 1, p. 107-113Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To validate a method for calculating split renal function from computed tomography (CT) compared with gamma camera renography, and to test a new method for the measurement based on a volume-rendering technique. MATERIAL AND METHODS: Thirty-eight patients, aged 65.7 +/- 11.6 (range 37.8-82.1) years, who had undergone both CT angiography and gamma camera renography for a suspected renal artery stenosis were included in this study. Split renal function was calculated from the CT examinations by measuring area and mean attenuation in the image slices of the kidneys, and also by measuring volume and mean attenuation from a 3D reconstruction of the kidneys. Gamma camera renography with 99mTc-MAG3 with or without captopril enhancement was used as a reference. RESULTS: The 2D CT method had good correlation with renography (r=0.93). Mean difference was 4.7 +/- 3.6 (0-12) percentage points per kidney. There was also excellent correlation between the two CT methods (r=1.00). CONCLUSION: CT is equivalent to renography in determining split renal function, and the measurement from the CT examination can be made more quickly and equally accurately with a 3D technique.

  • 11. Blystad, I
    et al.
    Warntjes, Jbm
    Smedby, Örjan
    Landtblom, A-M
    Lundberg, P
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Synthetic MRI of the brain in a clinical setting2012In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, no 10, p. 1158-1163Article in journal (Refereed)
    Abstract [en]

    Background

    Conventional magnetic resonance imaging (MRI) has relatively long scan times for routine examinations, and the signal intensity of the images is related to the specific MR scanner settings. Due to scanner imperfections and automatic optimizations, it is impossible to compare images in terms of absolute image intensity. Synthetic MRI, a method to generate conventional images based on MR quantification, potentially both decreases examination time and enables quantitative measurements.

    Purpose

    To evaluate synthetic MRI of the brain in a clinical setting by assessment of the contrast, the contrast-to-noise ratio (CNR), and the diagnostic quality compared with conventional MR images.

    Material and Methods

    Twenty-two patients had synthetic imaging added to their clinical MR examination. In each patient, 12 regions of interest were placed in the brain images to measure contrast and CNR. Furthermore, general image quality, probable diagnosis, and lesion conspicuity were investigated.

    Results

    Synthetic T1-weighted turbo spin echo and T2-weighted turbo spin echo images had higher contrast but also a higher level of noise, resulting in a similar CNR compared with conventional images. Synthetic T2-weighted FLAIR images had lower contrast and a higher level of noise, which led to a lower CNR. Synthetic images were generally assessed to be of inferior image quality, but agreed with the clinical diagnosis to the same extent as the conventional images. Lesion conspicuity was higher in the synthetic T1-weighted images, which also had a better agreement with the clinical diagnoses than the conventional T1-weighted images.

    Conclusion

    Synthetic MR can potentially shorten the MR examination time. Even though the image quality is perceived to be inferior, synthetic images agreed with the clinical diagnosis to the same extent as the conventional images in this study.

  • 12.
    Borota, Ljubisa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Jangland, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Åslund, Per-Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nyberg, Christoffer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Mahmoud, Ehab
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sakaguchi, Takuya
    Patz, Andreas
    Spot fluoroscopy: a novel innovative approach to reduce radiation dose in neurointerventional procedures2017In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, no 5, p. 600-608Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Increased interest in radiation dose reduction in neurointerventional procedures has led to the development of a method called "spot fluoroscopy" (SF), which enables the operator to collimate a rectangular or square region of interest anywhere within the general field of view. This has potential advantages over conventional collimation, which is limited to symmetric collimation centered over the field of view.

    PURPOSE: To evaluate the effect of SF on the radiation dose.

    MATERIAL AND METHODS: Thirty-five patients with intracranial aneurysms were treated with endovascular coiling. SF was used in 16 patients and conventional fluoroscopy in 19. The following parameters were analyzed: the total fluoroscopic time, the total air kerma, the total fluoroscopic dose-area product, and the fluoroscopic dose-area product rate. Statistical differences were determined using the Welch's t-test.

    RESULTS: The use of SF led to a reduction of 50% of the total fluoroscopic dose-area product (CF = 106.21 Gycm(2), SD = 99.06 Gycm(2) versus SF = 51.80 Gycm(2), SD = 21.03 Gycm(2), p = 0.003884) and significant reduction of the total fluoroscopic dose-area product rate (CF = 1.42 Gycm(2)/min, SD = 0.57 Gycm(2)/s versus SF = 0.83 Gycm(2)/min, SD = 0.37 Gycm(2)/min, p = 0.00106). The use of SF did not lead to an increase in fluoroscopy time or an increase in total fluoroscopic cumulative air kerma, regardless of collimation.

    CONCLUSION: The SF function is a new and promising tool for reduction of the radiation dose during neurointerventional procedures.

  • 13.
    Boström Ardin, Annika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Löfberg, A-M.
    Hellberg, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Andrén, Bertil
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Ljungman, Christer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Logason, K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Karacagil, Sadettin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty with duplex scanning2002In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, no 4, p. 391-395Article in journal (Refereed)
    Abstract [en]

    AIM: To evaluate the role of duplex scanning in the selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty (PTA).

    MATERIAL AND METHODS: From January 1995 through May 2000, 702 patients (952 limbs), with chronic lower extremity ischemia due to infrainguinal atherosclerotic disease diagnosed by duplex scanning, were retrospectively studied. Diagnostic angiography (130 limbs) or infrainguinal PTA (108 limbs) was performed in 238 limbs. Two investigators retrospectively analyzed the duplex examinations and angiographies in a blinded manner and used similar criteria for the interpretation of lesions suitable or not suitable for PTA.

    RESULTS: The superficial femoral, popliteal and crural artery lesions were correctly selected for PTA in 85%, 66% and 32%, respectively. The accuracy, sensitivity, specificity, negative predictive value and positive predictive value of duplex scanning to appropriately categorize femoropopliteal lesions as suitable or unsuitable for PTA were 89%, 83%, 92%, 94% and 78%, respectively. The accuracy of duplex scanning for predicting the performance of infrainguinal PTA was 83%.

    CONCLUSION: Duplex scanning has an important impact on the selection of treatment modalities in limbs with infrainguinal arterial occlusive disease. Femoropopliteal lesions can be reliably selected to PTA according to duplex scan findings.

  • 14. Carlson, K
    et al.
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Simonsson, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    MR imaging of multiple myeloma in tumour mass measurement at diagnosis and during treatment1995In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, no 1, p. 9-14Article in journal (Refereed)
    Abstract [en]

    The bone marrow of the spine, pelvis and proximal femora was examined with MR imaging at diagnosis in 30 cases of multiple myeloma (MM), and during treatment on 69 occasions. The MR pattern was normal, focal or diffuse and correlated to stage. A tumour mass index (TMI) was calculated by estimating the total myeloma mass visualised at MR imaging. The TMI correlated significantly with stage, lytic bone lesions, serum calcium, serum beta-2-microglobulin and survival. No abnormalities were seen at MR investigation in 4 of 6 patients classified as stage II because of osteoporosis only. Therapy efficacy evaluation with MR imaging corresponded to clinical evaluation on 54 of the 69 occasions. MR examination of bone marrow in MM patients can be used for tumour mass assessment, both at diagnosis and during follow-up. Valuable information can be obtained when the tumour mass is difficult to estimate using clinical criteria, e.g. in non-secretory MM or when osteoporosis is the only variable indicating an increase in the tumour mass.

  • 15.
    Ciray, Ipek
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Lindman, H
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Wanders, A
    Bergh, J
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on MR imaging of normal red bone marrow in breast cancer patients with focal bone metastases2003In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, no 5, p. 472-484Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To investigate the effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on normal red bone marrow MR imaging in breast cancer patients with focal bone metastases.

    MATERIAL AND METHODS: Fifteen breast cancer patients who were examined before and after chemotherapy with T1-weighted-SE and long echo-time inversion-recovery turbo-spin-echo (long TE IR-TSE) sequences in the thoracolumbar spine and pelvis were retrospectively studied. Nine of them received G-CSF therapy after the administration of each chemotherapy course. Of these 9 patients, the MR follow-ups were performed during G-CSF in 4 patients and after G-CSF therapy in 5 patients. Six patients did not receive G-CSF. Signal intensity (SI) changes in normal bone marrow were evaluated visually in all patients and quantitatively in 13 patients.

    RESULTS: In all 4 patients investigated during G-CSF therapy a diffuse, homogeneous SI increase on long TE IR-TSE was observed visually and quantitatively in initially normal bone marrow. This change obscured some focal lesions in 2 patients. No such SI change was visible after G-CSF therapy (p = 0.008) or in patients not receiving G-CSF. On T1-weighted images an SI decrease was found both during and after G-CSF therapy, but an increase occurred in patients not receiving G-CSF.

    CONCLUSION: G-CSF-supported chemotherapy can induce diffuse SI changes in normal red bone marrow on MR imaging. On long TE IR-TSE, the changes are visible during G-CSF treatment and can lead to misinterpretations in the response evaluation of bone metastases to therapy.

  • 16.
    Ciray, Ipek
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Lindman, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Bergh, J
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Early response of breast cancer bone metastases to chemotherapy evaluated with MR imaging2001In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, no 2, p. 198-206Article in journal (Other academic)
    Abstract [en]

    PURPOSE:

    To compare T1-weighted spin-echo and fat-suppressed long echo time inversion recovery turbo spin-echo (long TE IR-TSE) MR images in the evaluation of early response of breast cancer bone metastases to chemotherapy.

    MATERIAL AND METHODS:

    Eighteen breast cancer patients with known bone metastases were investigated prospectively by MR, using T1-weighted and long TE IR-TSE sequences on the sternum, spine, pelvis and proximal femora, before and after a median of 6 courses of chemotherapy. Therapeutic response evaluation with MR was based on change in tumor size assessed quantitatively by measuring all focal metastases, and change in pattern and signal intensity (SI) of the metastases, assessed visually. Combined response evaluation based on clinical findings, conventional radiography, and scintigraphy was used as reference.

    RESULTS:

    Progressive disease (2 patients) and no change (4 patients) were assessed equally well on both MR sequences. Long TE IR-TSE demonstrated partial response with higher accuracy than T1-weighted images, 58% (7/12 patients) vs. 17% (2/12 patients). In patients without progression there was an SI increase in or around the metastases in 6 patients on T1-weighted images and in 7 patients on long TE IR-TSE images.

    CONCLUSION:

    The long TE IR-TSE sequence demonstrated early partial response of breast cancer bone metastases to chemotherapy more accurately than the T1-weighted sequence.

  • 17.
    Ciray, Ipek
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Andréasson, I
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Edekling, T
    Hansen, J
    Bergh, J
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Evaluation of new sclerotic bone metastases in breast cancer patients during treatment2000In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 41, no 2, p. 178-182Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    According to the World Health Organization (WHO) criteria for response of bone metastases to therapy, new lesions indicate progressive disease. We intended to prove that a new sclerotic lesion on conventional radiography may also be a sign of a positive therapeutic response in a previously undetectable lytic metastasis.

    MATERIAL AND METHODS:

    In a previous placebo-controlled clinical trial of clodronate (Ostac) therapy, 139 breast cancer patients with bone metastases underwent both conventional radiography and bone scan every 6 months for 2 years with 99mTc before and during clodronate treatment. WHO criteria were applied for therapy response evaluation.

    RESULTS:

    In 24 patients, 52 new sclerotic lesions observed during therapy were selected for re-evaluation of conventional radiographs and bone scans. In 8 of the 24 patients, 17 of 52 new sclerotic lesions (33%) had showed positive uptake on previous bone scans. These lesions were possibly misinterpreted as new when applying WHO criteria.

    CONCLUSION:

    For better assessment of new sclerotic lesions during treatment, more sensitive techniques, e.g. bone scan, are needed as a complement to conventional radiography.

  • 18.
    Ciray, Ipek
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Åström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Sundström, Christer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular and Morphological Pathology.
    Hagberg, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Assessment of suspected bone metastases: CT with and without clinical information compared to CT-guided bone biopsy1997In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, no 5, p. 890-895Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To evaluate the role of CT with and without clinical information as compared to CT-guided bone biopsy in the assessment of suspected bone metastases.

    MATERIAL AND METHODS:

    The study comprised 51 consecutive patients with suspected bone metastases who had undergone CT-guided bone biopsies with an eccentric drill system. CT of the targets, clinical information, and histopathology were scored separately as malignant, uncertain or benign. The results of CT alone and CT in combination with clinical information were compared to the results of histopathology.

    RESULTS:

    Histopathology diagnosed 45/51 lesions (88%), 23 as malignant and 22 as benign. CT correctly depicted 17 of these 23 malignant lesions. The remaining 6 malignant lesions were CT-scored as uncertain (n = 5) or benign (n = 1). CT correctly depicted only 3 of the 22 benign lesions. The remaining 19 benign lesions were CT-scored as malignant (n = 2) or uncertain (n = 17). When uncertain CT scores were combined with clinical scores, the true-positive and true-negative results for malignancy increased from 44% to 82%.

    CONCLUSION:

    In most cases, CT in combination with clinical information gives enough information about the nature-malignant or benign-of a skeletal lesion. In uncertain cases, diagnostic accuracy can be improved by means of CT-guided bone biopsy.

  • 19.
    Dahlman, Pär
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Jangland, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Segelsjö, Monika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Optimization of computed tomography urography protocol, 1997 to 2008: effects on radiation dose2009In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, no 4, p. 446-454Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Since computed tomography (CT) urography began to replace excretory urography as the primary imaging technique in uroradiology, the collective radiation dose to the patients has increased. PURPOSE: To examine the changes in the CT urography protocol for investigating suspected urinary tract malignancy between the years 1997 and 2008, and how these changes have influenced the mean effective dose. MATERIAL AND METHODS: The study was based on 102 patients (mean age 66.1+/-14.8 years, range 31-89 years; 30 female, 72 male) divided into five groups (groups A-E) corresponding to the time points at which changes were made to the CT urography protocol. The mean effective doses were estimated using the ImPACT CT Patient Dosimetry Calculator. RESULTS: The number of scan phases at CT urography was reduced from four to three in 1999, resulting in a reduction of the mean effective dose from 29.9/22.5 (female [F]/male [M]) mSv (group A) to 26.1/18.9 (F/M) mSv (group B). In 2001, mAs settings were adapted to patient size, and the mean effective dose was reduced to 16.8/12.0 (F/M) mSv (group C). In 2005, scans were performed with a multidetector-row CT equipped with automatic tube current modulation in the x- and y-axis (CARE Dose). The effective mAs was also lowered in the unenhanced and excretory phase, yet the mean effective dose increased to 18.2/13.1 (F/M) mSv (group D), since the effective mAs had to be increased in the corticomedullary phase to maintain image quality. In 2008, as tube current modulation in the x-, y-, and z-axis was introduced (CARE Dose4D), the mean effective dose was reduced to 11.7/8.8 (F/M) mSv (group E). CONCLUSION: This study shows that the individual mean effective dose to patients undergoing CT urography has decreased by 60%, from 29.9/22.5 (F/M) mSv in 1997 to 11.7/8.8 (F/M) mSv in 2008.

  • 20.
    Dahlman, Pär
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Semenas, Egidijus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Brekkan, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Bergman, Antonina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Detection and characterisation of renal lesions by multiphasic helical CT.2000In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Acta Radiol., Vol. 41, no 4, p. 361-366Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The fast helical CT technique allows examination of the kidneys during different phases of contrast medium enhancement. However, every additional phase increases the radiation dosage to the patients. We investigated the detection rate and characterisation of renal lesions during different phases and evaluated them separately, and considered the possibility of excluding phases without loss of important information.

    MATERIAL AND METHODS: Sixty patients who underwent contrast-enhanced multiphasic renal helical CT examination were included. Every CT phase was evaluated separately. The number of lesions and the characteristics of the lesions were noted and all lesions were viewed together.

    RESULTS: A total of 153 cysts and 17 solid lesions were detected. The largest and an equal number of cysts (142/143) was detected in the nephrographic and excretory phases. However, the nephrographic phase detected more cortical cysts and the excretory phase detected more sinus cysts. All solid lesions were detected in all phases. Renal parenchymal tumours were best characterised in the cortical phase and angiomyolipomas in the native phase.

    CONCLUSION: The cortical phase was best for characterisation of renal parenchymal tumours. The nephrographic and excretory phases were best in detecting and characterising renal cysts. The nephrographic phase was the phase giving the least diagnostic information.

  • 21.
    Dimopoulou, Angeliki
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Raland, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Wikström, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    MDCT angiography with 3D image reconstructions in the evaluation of failing arteriovenous fistulas and grafts in hemodialysis patients2011In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, no 9, p. 935-942Article in journal (Refereed)
    Abstract [en]

    Background: Arteriovenous fistulas and grafts are the methods of choice for vascular access in renal failure patients in need of hemodialysis. Their major complication, however, is stenosis, which might lead to thrombosis.

    Purpose: To demonstrate the usefulness of 16-MDCTA with 3D image reconstructions, in long-term hemodialysis patients with dysfunctional arteriovenous fistulas and grafts (AVF and AVG).

    Material and Methods: During a 17-month period, 31 patients with dysfunctional AVF and AVG (24 AVF and seven AVG) were examined with MDCTA with 3D image postprocessing. Parameters such as comprehension of the anatomy, quality of contrast enhancement, and pathological vascular changes were measured. DSA was then performed in 24 patients.

    Results: MDCTA illustrated the anatomy of the AVF/AVG and the entire vascular tree to the heart, in a detailed and comprehensive manner in 93.5% of the evaluated segments, and depicted pathology of AVF/AVG or pathology of the associated vasculature. MDCTA demonstrated a total of 38 significant stenoses in 25 patients. DSA verified 37 stenoses in 24 patients and demonstrated two additional stenoses. MDCTA had thus a sensitivity of 95%. All 24 patients were treated with percutaneous transluminal angioplasty (PTA) with good technical results.

    Conclusion: MDCTA with 3D reconstructions of dysfunctioning AVFs and AVGs in hemodialysis patients is an accurate and reliable diagnostic method helping customize future intervention.

  • 22. Dormagen, Johann B.
    et al.
    Tötterman, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    Røise, Olav
    Sandvik, Leiv
    Kløw, Nils-E.
    Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients2010In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 51, no 1, p. 107-16Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. PURPOSE: To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. MATERIAL AND METHODS: 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm(2). AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. RESULTS: Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm(2) posteriorly and >29 cm(2) anteriorly revealed specificity of 0.85 and 0.86, respectively. CONCLUSION: CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may contribute equally to effective assessment of injured arteries.

  • 23.
    Duvernoy, Olov
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Borowiec, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Thoracic Surgery.
    Helmius, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Erikson, Uno
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Complications of percutaneous pericardiocentesis under fluoroscopic guidance1992In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 33, no 4, p. 309-313Article in journal (Refereed)
    Abstract [en]

    Complications in 352 cases of fluoroscopy-guided percutaneous pericardiocentesis accomplished through an indwelling catheter were reviewed following surgery and non-surgery. Thirteen major complications were found, namely 3 cardiac perforations, 2 cardiac arrhythmias, 4 cases of arterial bleeding, 2 cases of pneumothorax in children, one infection, and one major vagal reaction. No significant difference in complications was found between pericardiocenteses for pericardial effusions after cardiac surgery (n = 208) and those for effusions of non-surgical (n = 144) origin. Fluoroscopy-guided pericardiocentesis by the subxiphoid approach with placement of an indwelling catheter is a safe method for achieving pericardial drainage in both surgical and non-surgical effusions. Accidental cardiac perforation with a fine needle is a minor complication as long as the needle is directed towards the anterior diaphragmatic border of the right ventricle and drainage is achieved with a reliable indwelling catheter.

  • 24.
    Ebeling Barbier, Charlotte
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Lind, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Bjerner, Thomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    The exactness of left ventricular segmentation in cine magnetic resonance imaging and its impact on systolic function values2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 3, p. 285-291Article in journal (Refereed)
    Abstract [en]

    Purpose: To evaluate the impact of exactness of the segmentation of the left ventricle (LV), using cine magnetic resonance imaging (MRI). Material and methods: Steady-state free-precession cine MRI was performed on 100 randomly selected subjects. Myocardial borders were outlined on short-axis images using three methods: method 1 was computer assisted, excluding papillary muscles from the left ventricular mass (LVM); method 2 was similar but included papillary muscles; and method 3 was manually traced including papillary muscles. LV end-systolic (ES) and end-diastolic (ED) masses and volumes, ejection fraction (EF), stroke volume (SV), and cardiac output (CO) were calculated from these measurements. The difference between the ES and ED LVM was used to estimate the exactness of the methods. Results: Method 3 was the most exact, and method 1 was the least exact. The three methods generated differing EF, SV, and CO measurements. With an ES-ED LVM difference exceeding 20 g, the mean SV measurement error was 8.83.6 ml. Conclusion: Manual tracing proved more exact than computer-assisted quantification. Exactness had an impact on EF, SV, and CO measurements, and the ES-ED LVM difference can be used to identify assessments that would benefit from more exact segmentation.

  • 25.
    Eklöf, Hampus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Boström-Ardin, A.
    Bergqvist, David
    Andrén, Bertil
    Karacagil, Sadettin
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Renal artery stenosis evaluated with magnetic resonance angiography using intraarterial pressure gradient as the standard of reference: A multireader study2005In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, no 8, p. 802-809Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate 3D-Gd-magnetic resonance angiography (MRA) in detecting hemodynamically significant renal artery stenosis (RAS). MATERIAL AND METHODS: Thirty patients evaluated for atherosclerotic RAS by MRA and digital subtraction angiography (DSA) were retrospectively included. Standard of reference for hemodynamically significant RAS was a transstenotic gradient of 15 mmHg. DSA visualized 60 main renal arteries and 9 accessory arteries. Pressure gradient measurement (PGM) was available from 61 arteries. Three radiologists evaluated all examinations independently in a blinded fashion. RESULTS: RAS was present in 26 arteries. On MRA, each reader identified 4 of 9 accessory renal arteries, a detection rate of 44%. The three readers correctly classified 22/25/22 of the 26 vessels with a significant gradient as > or =60% RAS and 31/25/32 of the 35 with no significant gradient as < 60% RAS on MRA. Interobserver agreement was substantial. MRA image quality was adequate for RAS evaluations in all patients. ROC curves indicated that MRA is an adequate method for evaluating RAS. When screening for RAS, a 50% diameter reduction cut-off is better than 60%. RAS with 40-80% diameter reductions accounted for 65% of discrepancies. CONCLUSION: MRA is an adequate method for evaluating RAS limited mainly by poor detection rate for accessory renal arteries.

  • 26.
    Eklöf, Hampus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Magnusson, Ann christin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Andersson, Lars-Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology.
    Andrén, Bertil
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology.
    Hägg, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Bergqvist, David
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    A prospective comparison of duplex ultrasonography, Captopril renography, MRA and CTA in assessing renal artery stenosis2006In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, no 8, p. 764-774Article in journal (Refereed)
    Abstract [en]

    Purpose: To prospectively compare the diagnostic accuracy of duplex ultrasonography, captopril renography, computed tomography angiography (CTA), and 3D Gd magnetic resonance angiography (MRA) in diagnosing hemodynamically significant renal artery stenosis (RAS).

    Material and Methods: The standard of reference was measurement of transstenotic pressure gradient. Fifty-eight hypertensive patients with suspicion of RAS were evaluated, when possible, by all five techniques. Sensitivity and specificity to detect RAS were compared for each technique on both a patient and kidney basis. Discrepancies were evaluated separately and classified as borderline, method dependent, or operator dependent.

    Results: The prevalence of RAS was 77%. The sensitivity/specificity of ultrasonography, captopril renography, CTA, and MRA in detecting kidneys with RAS was 73/71%, 52/63%, 94/62%, and 93/91%, respectively. Ultrasonography had a significantly lower sensitivity than CTA and MRA (P < 0.001) but higher than captopril renography (P = 0.013). Borderline RAS was the main cause for discrepancies.

    Conclusion: MRA and CTA were significantly better than duplex ultrasonography and captopril renography in detecting hemodynamically significant RAS. The ultrasonography criteria for RAS based on the evaluation of renal peak systolic velocity and renal/aortic ratio are questionable. Captopril renography cannot be recommended for assessing RAS.

  • 27.
    Eklöf, Hampus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Bergqvist, David
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Hägg, A.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Outcome after endovascular revascularization of atherosclerotic renal artery stenosis2009In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, no 3, p. 256-64Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: With an aging population, more patients might be treated for atherosclerotic renal artery stenosis (ARAS). The goal of this treatment is to achieve a dialysis-free life or a well-controlled blood pressure with reduced risks of cardiovascular complications. PURPOSE: To analyze the clinical outcome of percutaneous transluminal renal artery angioplasty without stenting (PTRA) or with stenting (PTRS) for ARAS at one center. MATERIAL AND METHODS: The study group comprised 152 patients who underwent 203 PTRA/PTRS. All had hypertension, and 45% had azotemia. A retrospective collection of baseline and postprocedural number of antihypertensive drugs, blood pressure, and serum creatinine were analyzed during a follow-up of 3-18 months. RESULTS: Technical success rate was 95%, and clinical benefit was seen in 63% of patients. Complications included a 30-day mortality rate of 1.5%, a total complication rate of 35%, and major adverse events in 13%. The major adverse events were highly related to azotemia. Major adverse events within 30 days, with permanent disability, were seen in 5% and almost exclusively in patients with moderate or severe renal impairment. A subgroup analysis of 28 patients with renal duplex resistive index (RI) pre-PTRA/S and 6 months' follow-up showed a benefit of PTRA/PTRS in 17 (68%) of the 25 patients with RI <80 and in all three (100%) of the patients with RI >or=80. CONCLUSION: Endovascular treatment of ARAS has an excellent technical success rate, with a clinical improvement rate of >60%. However, it is associated with a considerable complication rate. Serious complications are seen mainly in azotemic patients. Predictors of clinical response could not be identified. Renal duplex RI is questioned as a predictor of clinical outcome.

  • 28.
    Eklöf, Hampus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Radecka, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Liss, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Teleradiology Uppsala-Sydney for nighttime emergencies: preliminary experience2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 8, p. 851-853Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The development of digital imaging systems for radiology in combination with the possibility to transfer large quantities of data over the Internet has increased the interest in teleradiology. Transferring nighttime examinations to an evaluation center in a daytime zone may provide improved patient security, better working hours for radiologists, and reduced costs for emergency radiological services. PURPOSE: To evaluate the time required for transferring radiological information from Uppsala (Sweden) to Sydney (Australia). MATERIAL AND METHODS: A radiologist in Sydney reported on radiological examinations performed in Uppsala. The time required for downloading 75 examinations and returning 24 reports was registered. RESULTS: Downloading was completed in <60 min for all conventional radiological examinations, but only 44% of computed tomography (CT) examinations with >65 images. Reports were completed in <10 min. Turnaround time was directly related to the time required for downloading the images. The Sydney report was available in Uppsala within 30 min of the in-house report in 79% of examinations. CONCLUSION: The main challenge for emergency teleradiology is the time required for downloading large volumes of data over the Internet.

  • 29.
    Eklöf, Hampus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Smedby, Örjan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ljungman, C.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Karacagil, Sadettin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Bergqvist, David
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    2D inflow MR angiography in severe chronic leg ischemia1998In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, no 6, p. 663-668Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The aim of this study was to compare 2D inflow MR angiography (MRA) with selective X-ray angiography (XRA) in patients with severe chronic leg ischemia. MATERIAL AND METHODS: In a blinded prospective study, 2D inflow MRA and XRA were compared with regard to evaluation of the arteries distal to the knee in 24 patients (median age 72 years) with severe ischemia; 23 of them had either rest pain or tissue loss. Statistics were calculated with XRA as the reference method. RESULTS: The interpretations of 2D inflow MRA and XRA showed moderate agreement in the calf arteries but poor agreement in the foot arteries. Of the discrepancies, two-thirds were observer-related and only one-third method-related. Of all the comparable arteries, 9% showed method-related differences between the two methods. An assessment of MRA using only maximum intensity projections (MIP) resulted in 19% of findings being judged inconclusive whereas all the arteries could be classified when the cross-sectional images were studied on the viewing console. CONCLUSION: The agreement between MRA and XRA was good in the calf but questionable in the foot.

  • 30. Elvin, A
    et al.
    Wilander, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular and Morphological Pathology.
    Öberg, Kjell
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Eriksson, Barbro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lindgren, PG
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ultrasound guided biopsies of neuroendocrine metastases: Comparison of 0.9 and 1.2 mm biopsy-gun needle biopsies1993In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 34, no 5, p. 474-477Article in journal (Refereed)
    Abstract [en]

    Twenty-five patients with known neuroendocrine tumour disease were biopsied with 1.2 mm and 0.9 mm biopsy-gun needles to evaluate the respective diagnostic accuracy of the 2 needle sizes. The influence of treatment-related fibrosis on the histopathological diagnosis was also evaluated. The overall diagnostic accuracy with the 0.9 mm needle was 69% as compared to 92% with the 1.2 mm needle. This difference, however, seems more related to needle guiding difficulties with the 0.9 mm needle than to insufficient tissue yield. When the tumour was hit with both the 0.9 and the 1.2 mm needle the tissue yield was inferior with the 0.9 mm needle in only one of 16 cases. The increased amount of fibrous tissue due to interferon treatment did not seem to negatively influence the diagnostic accuracy.

  • 31.
    Eriksson, Lars-Gunnar
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Lutvica-Mulic, Ajlana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
    Jangland, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Massive Postpartum Hemorrhage Treated with Transcatheter Arterial Embolization: Technical aspects and long-term effects on fertility and menstrual cycle2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 6, p. 635-642Article in journal (Refereed)
    Abstract [en]

    Background: Transcatheter arterial embolization (TAE) is considered a safe, life-saving procedure in postpartum hemorrhage (PPH), but its long-term effect on menstruation and fertility is unclear. Purpose: To investigate technical aspects and the evaluation of complications, focused on menstrual cycle and fertility, using TAE in patients with PPH. Material and Methods: A retrospective study including 20 patients (seven with vaginal and 13 with cesarean delivery) with severe PPH treated with bilateral TAE of the uterine artery was carried out. All patients were asked to answer a questionnaire regarding their post-embolization history. In six patients, the radiation dose was measured. Results: All 20 cases underwent bilateral TAE of the uterine artery. Gelfoam was used as the embolic agent. However, after cesarean delivery in six patients who had clear contrast medium extravasation and/or pseudoaneurysm-like lesion, metallic coils had to be used in order to achieve hemostasis. No major short- or long-term complications were registered. Normal menses resumed in all patients. Four patients had a total of five full-term and two preterm pregnancies, and all delivered healthy infants by cesarean section with no recurrence of PPH. The mean radiation dose to the ovaries was 586 mGy (range 204-729 mGy). Conclusion: TAE in patients with PPH is safe and has no major short- or long-term side effects. A patient managed with TAE can expect return of normal menses and preservation of future fertility and successful pregnancies. PPH after cesarean section might need to be embolized with metallic coils in addition to Gelfoam in order to achieve secure hemostasis.

  • 32.
    Eriksson, Mats-Ola
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    The value of intravascular phased-array imaging in endovascular treatment of thoracic aortic pathology2011In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, no 3, p. 285-290Article in journal (Refereed)
    Abstract [en]

    Background Careful pre-, intra- and postoperative diagnostics in endovascular treatment of thoracic aortic pathology is crucial for a favourable outcome. Computer tomography (CT) and digitally subtracted angiography (DSA) do not always provide sufficient diagnostic information. Purpose To report our primary experiences of using intraluminal phased-array imaging (IPAI) as an additive tool for diagnostics and endovascular treatment of thoracic aortic pathology. Material and Methods Eleven patients, nine men and two women (mean age 60, range 45) were examined intraoperatively with IPAI in stentgraft procedures of thoracic aortic pathology. Results IPAI could detect and visualize the entries and re-entries in the intima. Aortic branch vessels could be visualized for patency both during and immediately after stentgraft deployment. It was also possible to detect ceased blood flow in the false lumen or aneurysmal sac after stentgraft deployment. Conclusion IPAI is a helpful tool for diagnostics and for guiding stentgraft placing in the treatment of thoracic aortic pathology.

  • 33.
    Eriksson, Mats-Ola
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Wanhainen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Intravascular Ultrasound with a Vector Phased-Array Probe (AcuNav) Is Feasible in Endovascular Abdominal Aortic Aneurysm Repair2009In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, no 8, p. 870-875Article in journal (Refereed)
    Abstract [en]

    Background: The ideal imaging method for endovascular aneurysm repair (EVAR) should provide all data regarding diagnosis, measurements, and guiding of stent-graft deployment. Contrast-enhanced computed tomography (CT) is used for preoperative EVAR planning, together with intraoperative angiography. However, the administered contrast volume might result in contrast-induced nephropathy (CIN). Purpose: To develop a technique for aortic measurements, vessel wall evaluation, and stent-graft positioning by using a vector phased-array intravascular ultrasound probe with color Doppler function (AcuNav) in elective EVAR. Material and Methods: Thirteen elective EVAR patients were included. AcuNav was compared to pre- and postoperative CT examinations, perioperative angiography, and postoperative duplex. Results: Measurements for stent-graft sizing were easily obtained and facilitated by the color Doppler function and corresponded well with CT and angiography. The combined information from AcuNav and fluoroscopy provided exact positioning of the stent graft. An aortic placement of the probe provided superior imaging results compared to an inferior vena cava approach. Detection of endoleak was found to be difficult. No complications were registered. Conclusion: The use of AcuNav combined with fluoroscopy in EVAR was found to be safe, effective, and feasible in planning and guiding EVAR procedures. Best results were seen with the probe placed in the artery. AcuNav might be used to replace contrast-enhanced CT and angiography, hence reducing the risk of CIN, especially in high-risk patients.

  • 34.
    Eriksson, Thomas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Berg, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    Olerud, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    Shalabi, Adel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Hänni, Mari
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Low-dose CT of postoperative pelvic fractures: a comparison with radiography2019In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, no 1, p. 85-91Article in journal (Refereed)
    Abstract [en]

    Background Computed tomography (CT) is superior to conventional radiography (CR) for assessing internal fixation of pelvic fractures, but with a higher radiation exposure. Low-dose CT (LDCT) could possibly have a sufficient diagnostic accuracy but with a lower radiation dose. Purpose To compare postoperative diagnostic accuracy of LDCT and CR after open reduction and internal fixation of pelvic fracture. Material and Methods Twenty-one patients were examined with LDCT and CR 0-9 days after surgery. The examinations were reviewed by two musculoskeletal radiologists. Hardware, degree of fracture reduction, image quality, and reviewing time were assessed, and effective radiation dose was calculated. Inter-reader agreement was calculated. Results LDCT was significantly better than CR in determining whether hardware positioning was assessable ( P < 0.001). Acetabular congruence was assessable in all fractured patients with LDCT. In 12 of the 32 assessments with CR of patients with an acetabular fracture, joint congruence was not assessable due to overlapping hardware ( P = 0.001). Image quality was significantly higher for LDCT. Median time to review was 240 s for LDCT compared to 180 s for CR. Effective dose was 0.79 mSv for LDCT compared to 0.32 mSv for CR ( P < 0.001). Conclusion LDCT is more reliable than CR in assessing hardware position and fracture reduction. Joint congruency is sometimes not possible to assess with CR, due to overlapping hardware. The image quality is higher, but also the effective dose, with LDCT than with CR.

  • 35.
    Eriksson, Thomas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Maguire, Gerald Q
    Noz, Marilyn E
    Zeleznik, Michael P
    Olivecrona, Henrik
    Shalabi, Adel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Hänni, Mari
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Are low-dose CT scans a satisfactory substitute for stereoradiographs for migration studies? A preclinical test of low-dose CT scanning protocols and their application in a pilot patient.2019In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, article id 284185119844166Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Computed tomography (CT) has the potential to acquire the data needed for migration studies of orthopedic joint implants of patients who have had tantalum beads implanted at the time of joint replacement surgery. This can be accomplished with the same precision as radiostereometric analysis (RSA). Switching to CT would increase availability without the need for the specific facilities required for RSA. However, higher effective dose is a concern.

    PURPOSE: To investigate if migration measurements can be done with CT with an accuracy and effective dose comparable to that of conventional RSA.

    MATERIAL AND METHODS: Fourteen scanning protocols were tested in a hip phantom that incorporated tantalum beads and an uncemented femoral stem. The protocols were graded for clinical practice according to the three parameters of image quality, effective dose, and robustness of numerical data. After grading, the two protocols that graded best overall were applied to a pilot patient.

    RESULTS: All protocols produced scans in which the numerical data were sufficient for a migration analysis at least as precise as would be expected using RSA. A protocol with an effective dose of 0.70 mSv was shown to be applicable in a pilot patient.

    CONCLUSION: Low-dose CT scans with an effective dose comparable to a set of routine plain radiographs can be used for precise migration measurements.

  • 36. Frennby, Bo
    et al.
    Almén, Torsten
    Lilja, Bo
    Eriksson, Lars-Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Hellsten, Sverker
    Lindblad, Bengt
    Nilsson, Mats
    Nyman, Uif
    Törnquist, Carl
    Determination of the relative glomerular filtration rate of each kidney in man: Comparison between iohexol CT and 99mTc-DTPA scintigraphy1995In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, no 4, p. 410-417Article in journal (Refereed)
    Abstract [en]

    Iohexol and 99mTc-DTPA were used in 43 patients to determine the relative glomerular filtration rate (GFR), i.e., the GFR of each kidney in percent of total GFR. The amount of any GFR marker accumulating in Bowman's space, tubuli and renal pelvis within a few minutes after i.v. injection, before any marker had left the kidney via the ureter, was defined as proportional to the GFR of that kidney. The renal accumulation of iohexol was determined by CT using 10 slices of 8-mm thickness 1 to 4 minutes after injection. The renal accumulation of 99mTc-DTPA was determined with a gamma camera within 2 minutes after injection. The correlation coefficient between the two methods was 0.98. Due to the higher radiation dose from CT than from 99mTc-DTPA injection, relative GFR determination with CT should be performed when there is also a diagnostic need to reveal morphology.

  • 37.
    Gao, Xiang
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Sandberg, Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Quach, My
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Bodin, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Jansson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Effects of Mn-DPDP and manganese chloride on hemodynamics and glucose tolerance in anesthetized rats2014In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, no 3, p. 328-334Article in journal (Refereed)
    Abstract [en]

    Background Previous studies have demonstrated that magnetic resonance imaging may be a method of choice to visualize transplanted pancreatic islets. However, contrast agents may interfere with microcirculation and affect graft function. Purpose To evaluate the effects manganese-containing contrast media on regional blood flow and glucose tolerance. Material and Methods Anesthetized rats were injected intravenously with MnCl2 (10 mu M/kg body weight) or Mn-DPDP (Teslascan; 5 mu M/kg body weight). Blood flow measurements were made with a microsphere technique 10min later. In separate animals vascular arteriolar reactivity in isolated, perfused islets was examined. Furthermore, an intraperitoneal glucose tolerance test was performed in separate rats. Results Glucose tolerance was unaffected by both agents. No changes in regional blood flow were seen after administration of Mn-DPDP, except for an increase in arterial liver blood flow. MnCl2 increased all blood flow values except that of the kidney. MnCl2, but not Mn-DPDP, caused a vasoconstriction in isolated rat islet arterioles but only at very high doses. Conclusion Mn-DPDP administration does not affect glucose tolerance or regional blood flow, besides an increase in arterial hepatic blood flow, and may therefore be suitable for visualization of islets.

  • 38.
    Granberg, Dan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Eriksson, Lars-Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Welin, Staffan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Kindmark, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Janson, Eva Tiensuu
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Skogseid, Britt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Öberg, Kjell
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Eriksson, Barbro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Nyman, Rickard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Liver embolization with trisacryl gelatin microspheres (embosphere) in patients with neuroendocrine tumors2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 2, p. 180-185Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To report our experience of liver embolization with trisacryl gelatin microspheres (Embospheretrade mark) in patients with metastatic neuroendocrine tumors.

    MATERIAL AND METHODS:

    Fifteen patients underwent selective embolization of the right or left hepatic artery with Embosphere. One lobe was embolized in seven patients and both lobes, on separate occasions, in eight patients. Seven patients had midgut carcinoids, two had lung carcinoids, one suffered from a thymic carcinoid, and five had endocrine pancreatic tumors. Eight patients suffered from endocrine symptoms, seven of whom had carcinoid syndrome and one WDHA (watery diarrhea, hypokalemia, achlorhydria) syndrome.

    RESULTS:

    Partial radiological response was seen after eight embolizations (in six different patients), stable disease was observed after 13 embolizations (after three of these, necroses occurred), while radiological progression was noted after only two embolizations. Only two patients experienced a biochemical response. Clinical improvement of carcinoid syndrome was observed after five embolizations. There were no major complications. Fever >38 degrees C was seen after all but four embolizations, and urinary tract infections were diagnosed after eight embolizations.

    CONCLUSION:

    Selective hepatic artery embolization with Embosphere particles is a safe treatment for patients with metastatic neuroendocrine tumors and may lead to partial radiological response as well as symptomatic improvement of disabling endocrine symptoms.

  • 39.
    Gustafsson, O.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Rossitti, Sandro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Ericsson, A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    MR imaging of experimentally induced intracranial hemorrhage in rabbits during the first 6 hours1999In: Acta Radiologica, ISSN 0284-1851, Vol. 40, no 4, p. 360-8Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate the MR appearance of intracranial, especially intraparenchymal, hemorrhage during the first 6 hours after bleeding with various pulse sequences in an animal model. MATERIAL AND METHODS: Intracerebral hematomas and subarachnoid hemorrhage were created by injecting autologous blood in 9 rabbits. MR studies were performed using a 1.5 T scanner with pixel size and slice thickness comparable to those used in clinical practice before blood injection, immediately after injection, and at regular intervals during 6 hours. The images were compared with the hematoma sizes on formalin-fixed brain slices. RESULTS: In every animal, susceptibility-weighted gradient-echo (GRE) pulse sequences depicted the intraparenchymal hematomas and blood escape in the ventricles or subarachnoid space best as areas of sharply defined, strong hypointensity. The findings remained essentially unchanged during follow-up. The sizes corresponded well to the post-mortem findings. Gradient- and spin-echo (GRASE) imaging revealed some hypointensities, but these were smaller and less well defined. Spin-echo (SE) sequences (proton density-, T1- and T2-weighted) as well as a fluid-attenuated inversion recovery turbo spin-echo sequence (fast FLAIR) depicted the hemorrhage sites as mostly isointense to brain. CONCLUSION: Susceptibility-weighted GRE imaging at 1.5 T is highly sensitive to both hyperacute hemorrhage in the brain parenchyma and to subarachnoid and intraventricular hemorrhage.

  • 40.
    Hagen, Gaute
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Wadström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Magnusson, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Outcome after percutaneous transluminal angioplasty of arterial stenosis in renal transplant patients2009In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, no 3, p. 270-275Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Ensuring graft survival in renal transplant patients is of paramount importance. Early detection and treatment of complications such as transplant renal artery stenosis (TRAS) are essential. PURPOSE: To evaluate the technical and clinical success rate of renal transplant patients with stenosis in the transplant renal artery or in the iliac artery after percutaneous transluminal angioplasty (PTA). MATERIAL AND METHODS: PTA was carried out on 24 patients with TRAS or iliac artery stenosis. Altogether, 28 stenoses were treated with PTA. The immediate technical result and the clinical outcomes after 1 and 3 months were assessed as well as clinical adverse events. A reduction in serum creatinine and/or a reduction in the number of antihypertensive drugs were criteria for clinical success. RESULTS: The immediate technical success rate after PTA was 93%. The clinical success rate after 1 month was 58%, increasing to 75% after 3 months. CONCLUSION: The technical success rate is not equivalent to the clinical success rate when treating TRAS with PTA. Furthermore, there is a delay in clinical response, sometimes of 3 months, after a technically successful PTA.

  • 41.
    Hagen, Gaute
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Wadström, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Eriksson, Lars-Gunnar
    Magnusson, Petter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. RAD.
    Magnusson, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Three-dimensional rotational angiography of transplanted renal arteries: influence of an extended angle of rotation on beam-hardening artifacts2005In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, no 2, p. 170-176Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To investigate whether three-dimensional rotational angiography (3D-RA) of the transplant renal artery performed with an extended angle of rotation can reduce beam-hardening artifacts in 3D reconstructed images without image quality being lost or side effects to the transplanted kidney being increased.

    MATERIAL AND METHODS:

    3D-RA with a C-arm rotation of 180 degrees was performed consecutively in 12 renal transplanted patients with suspicion of renal artery stenosis. A 1.7-mm balloon occlusion catheter was placed using the crossover technique and this was compared to a protocol with 160 degrees rotation and a traditional 1.4-mm catheter in 10 patients. The occurrence of beam-hardening artifacts was registered and the effects of the reduced contrast load on image quality and of arterial occlusion on renal function were assessed.

    RESULTS:

    The extended angle of rotation, from 160 degrees to 180 degrees, reduced the beam-hardening artifacts. Artifacts were observed in 4/11 patients (36%) in the study group and in all 10 (100%) of the controls. There was no statistical difference regarding image quality between the two protocols. Renal function was equally affected in both protocols.

    CONCLUSION:

    3D-RA with an extended C-arm rotation reduced the beam-hardening artifacts. Image quality was not reduced despite the reduced contrast medium load. The different protocols had no effect on patient outcome.

  • 42.
    Helenius, Malin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Magnusson, Mats
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Contrast enhancement in bladder tumors examined with CT urography using traditional scan phases2014In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, no 9, p. 1129-1136Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    Bladder assessment in an early contrast-enhancing computed tomography urography (CTU) phase requires that bladder tumors be enhanced using contrast material.

    PURPOSE:

    To investigate the enhancement pattern in bladder tumors using a CTU protocol where the scan is enhancement triggered.

    MATERIAL AND METHODS:

    Fifty patients diagnosed with bladder cancer were examined during the unenhanced (UP), corticomedullary (CMP), and excretory phases (EP). Twenty-one patients, all aged 50 years or older, were also examined during the nephrographic phase (NP). A ROI placed in the aorta was used to start the scan during the CMP when the attenuation reached 200 Hounsfield units (HU). The NP and EP were started with a 40 s and 300 s delay, respectively, after the CMP was finished. Attenuation and size measurements were made in the axial plane.

    RESULTS:

    Mean contrast enhancement of bladder tumors was 37, 25, and 17 HU in the CMP, NP, and EP, respectively. The differences in contrast enhancement were significant across all three phases. Eighty-eight percent of patients showed the highest contrast enhancement in the CMP. In 96% of the cases, contrast enhancement >20 HU was seen. The mean value of the shortest dimension of the bladder tumors was 22 ± 12 mm.

    CONCLUSION:

    The contrast enhancement is significantly higher in the CMP than in the NP and EP, suggesting that the CMP is preferable when assessing the bladder in the early contrast enhancing phase.

  • 43. Henriksson, Lars
    et al.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Smedby, Örjan
    Albrektsson, Per
    Assessment of congestive heart failure in chest radiographs: Observer performance with two common film-screen systems1990In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 31, no 5, p. 469-471Article in journal (Refereed)
    Abstract [en]

    The effect of observer variations and film-screen quality on the diagnosis of congestive heart failure based on chest radiographs was studied in 27 patients. For each patient, two films were exposed, one with the Kodak Lanex Medium system and one with the Agfa MR 400 system. The films were presented to three observers who assessed the presence of congestive heart failure on a three-graded scale. The results showed no significant difference between the two systems but large systematic differences between the observers. There were also differences between the two ratings by the same observer that could not be explained by the film-screen factor. It is concluded that the choice between these two systems is of little importance in view of the interobserver and intraobserver variability that can exist within the same department.

  • 44.
    Johansson, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Correlation between dose rate and T1 in blood at Gd-enhanced MR angiography1998In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, no 5, p. 579-582Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To determine the correlation between dose rate and T1 in blood at Gd-enhanced MR angiography (MRA).

    MATERIAL AND METHODS:

    A test dose of contrast agent was used to calculate the time delay between injection and arrival in the abdominal aorta. The dose rate was expressed as ml.kg b.w.-1.s-1. The correlation between dose rate and T1 was determined by varying the dose rate while keeping the scanning and infusion times constant. The signal intensity in the abdominal aorta was measured during the first pass of Gd and compared with markers of known T1 values.

    RESULTS:

    A correlation between dose rate and T1 in blood was obtained.

    CONCLUSION:

    A Gd dose rate of 0.01 ml.kg b.w.-1.s-1 gives a T1 in blood of 100 ms. This can be used to calculate the optimal pulse sequence for contrast-enhanced MRA.

  • 45.
    Johansson, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Kirchin, Miles A
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Gadobenate dimeglumine (MultiHance) in MR angiography: an in-vitro phantom comparison with gadopentetate dimeglumine (Magnevist) at different concentrations2012In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, no 10, p. 1112-1117Article in journal (Refereed)
    Abstract [en]

    Background

    Numerous clinical studies suggest that gadobenate dimeglumine is diagnostically superior to other gadolinium chelates for MR imaging applications, including contrast-enhanced MR angiography (CE-MRA). However, confirmatory in-vitro phantom studies have thus far been lacking.

    Purpose

    To evaluate the difference in signal intensity achieved with the high-relaxivity MR contrast agent gadobenate dimeglumine (MultiHance) relative to that achieved with the standard-relaxivity non-specific agent gadopentetate dimeglumine (Magnevist) at different concentrations using an in-vitro phantom study design.

    Material and Methods

    Test tubes with whole human blood were prepared with concentrations of gadobenate dimeglumine or gadopentetate dimeglumine ranging from 0 to 12 mM. A three-dimensional (3D) T1-weighted gradient echo sequence normally used for CE-MRA of the renal arteries was performed at flip angles of 25° and 35°. The signal-to-noise ratio (SNR) was calculated for all concentrations of both contrast agents. Furthermore a Look-Locker sequence was used and quantitative T1 mapping was performed for all the test tubes. The contrast agent concentration in the aorta was simulated using previously published data on T1 in the aorta during the first pass of a contrast agent. The differences between gadobenate dimeglumine and gadopentetate dimeglumine were compared at the simulated concentrations.

    Results

    The SNR achieved with gadobenate dimeglumine was consistently greater than that achieved with gadopentetate dimeglumine at all concentrations. An improvement of 15-25% in SNR was obtained when increasing the flip angle from 25° to 35°. The relative improvement in SNR with gadobenate dimeglumine relative to gadopentetate dimeglumine ranged from 25-72% and was markedly greater at lower concentrations with a flip angle of 35°.

    Conclusion

    Our findings suggest that the relative benefit of gadobenate dimeglumine over gadopentetate dimeglumine for CE-MRA applications is greater at lower concentrations.

  • 46. Kansoul, H A
    et al.
    Axelsson, R
    Yamamoto, Shinji
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Savicheva, I
    Aspelin, P
    Ericzon, B-G
    Gjertsen, H
    Parameters obtained by hepatobiliary scintigraphy have significant correlation with biochemical factors early after liver transplantation2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 6, p. 597-604Article in journal (Refereed)
    Abstract [en]

    Background: Early postoperative hepatobiliary scintigraphy after liver transplantation is performed worldwide, but data on its significance for graft function are currently limited.

    Purpose: To examine the correlation between the result of early postoperative hepatobiliary scintigraphy and pre- and postoperative biochemical parameters in liver transplantation (LTx) patients.

    Material and Methods: Six parameters of hepatobiliary scintigraphy using 99mTc mebrofenin were statistically analyzed in 108 LTx patients: 1) half-life of the activity of elimination of mebrofenin from the blood; 2) total clearance of mebrofenin from the blood due to all possible routes; 3) half-life of the activity due to liver uptake; 4) clearance of mebrofenin from the blood due to liver uptake; 5) time to maximal uptake in the liver; and 6) the hepatic extraction fraction (HEF) and biochemical data. Analysis between patients with preoperative normal liver function, familial amyloid polyneuropathy (FAP), and end-stage liver disease (non-FAP) was also performed.

    Results: Univariate and multivariate analysis revealed that total bilirubin postoperative day 3 correlated with all three scintigraphic parameters, and peak aspartate aminotransferase and alanine aminotransferase correlated with HEF. The analysis between patients with FAP and non-FAP revealed no significant difference of scintigraphic data between the two groups.

    Conclusion: A significant correlation between early postoperative scintigraphic results and biochemical parameters was demonstrated.

  • 47.
    Khoschnau, Shwan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    Larsson, Hans
    Radiology department, Sabbatsbergssjukhus, Stockholm.
    Elhami, Hojat
    Radiology department, Enköpingssjukhuset, Enköping.
    Rylance, Rebecca
    The southern Sweden musculoskeletal research center, department of orthopedics, Lund, Sweeden.
    Rahme, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    MRI without contrast is an unreliable method for detection of capsular reaction following shoulder surgery2012In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455Article in journal (Refereed)
    Abstract [en]

    Background

    Subacromial decompression is a common surgical procedure in patients with subacromial outlet impingement. The results are often good, although some patients develop adhesive capsulitis with postoperative pain and stiffness. The main aim of the present study was to analyze the reaction of the joint capsule 3 months after subacromial decompression using MRI without contrast.  We also wanted to study if there was a relation between the capsular reaction and the Constant score (CS) or the subjective shoulder value (SSV).

    Methods

    Forty-eight patients with a median age of fifty-six years underwent subacromial decompression with or without AC-joint resection. They were investigated with a standard x ray and MRI pre surgery and MRI three months after surgery. The CS and SSV were measured preoperatively and at three months, six months, and two years postoperatively for SSV. Two musculoskeletal radiologists independently evaluated the MRI images and used a scoring system from 0-7.

    Results

    The relationship between the baseline CS and the MRI pre-surgery score was significant for both raters. There were a significant difference between the raters’ pre and post-surgery average MRI scores, which simply means that there was a difference found in the average score between baseline and three months. However, the inter-rater reliability was poor. The improvement in the CS from baseline to three and six months postoperation was significant. The subjective shoulder value improved at three, six and 24 months after surgery.

    Conclusions

    MRI is an unreliable method to study capsular reaction in the shoulder joint due to the high subjectivity of the radiologists. Considerable improvements were observed in the CS and the SSV.

  • 48. Linder, G.
    et al.
    Carlsson, Per-Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Källskog, Örjan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Hansell, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Jansson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Riesenfeld Källskog, V.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Hemodynamic Effect of Iopromide in Pancreas-Duodenum Transplanted Rats2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 10, p. 1125-1130Article in journal (Refereed)
    Abstract [en]

    Background: Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation, especially in acute pancreatitis. Purpose: To evaluate the effects of the low-osmolar CM iopromide on total pancreatic and especially islet blood perfusion after whole pancreas transplantation. Material and Methods: Rats receiving a pancreas-duodenum transplantation 2 days earlier, i.e., with graft pancreatitis, were injected with iopromide. Blood perfusion measurements were then made with a microsphere technique. Results: The graft blood perfusion was decreased in control rats when compared to the endogenous pancreas. Administration of iopromide increased both total pancreatic and islet blood perfusion in the grafted pancreas, but not in the endogenous gland. No effects on blood perfusion to either the native or transplanted duodenum were seen after iopromide administration. Conclusion: Iopromide increases the blood perfusion of a whole pancreas transplant 2 days after implantation, i.e., when graft pancreatitis is present. The consequences of this CM-induced hyperperfusion for graft pancreatic function remain to be established.

  • 49.
    Linder, Gustaf
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Carlsson, Per-Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Källskog, Örjan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Hansell, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Jansson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Källskog, Vendela
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Radiological Contrast Media and Pancreatic Blood Perfusion in Anesthetized Rats2007In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, no 10, p. 1120-1124Article in journal (Refereed)
    Abstract [en]

    Background: Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation. Purpose: To evaluate the effects of an iso-osmolar (iodixanol, 290 mOsm/kg H2O) and a low-osmolar (iopromide, 660 mOsm/kg H2O) CM on total pancreatic and islet blood perfusion. Material and Methods: Thiobutabarbital-anesthetized rats were injected with iodine-equivalent doses (600 mg I/kg body weight) of iodixanol or iopromide. Saline or low-osmolar mannitol (660 mOsm/kg H2O) solutions served as control substances. Blood perfusion measurements were then carried out with a microsphere technique. Results: Iso-osmolar iodixanol had no effects on blood perfusion. Low-osmolar iopromide increased total pancreatic blood perfusion, whereas islet blood perfusion was unchanged. No differences were seen when mannitol solutions were given. Conclusion: Neither an iso-osmolar nor a low-osmolar CM affected pancreatic islet blood perfusion, whereas the low-osmolar CM increased total pancreatic blood perfusion. The absence of hemodynamic effect of low-osmolar mannitol suggests that the hyperosmolality per se of iopromide versus iodixanol does not induce the hemodynamic effect. The consequences of the effect of iopromide for pancreatic function remain to be established.

  • 50.
    Lundqvist, Eva
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Segelsjö, Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Andersson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Biglarnia, Ali-Reza
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Measurement of transplanted pancreatic volume using computed tomography: reliability by intra- and inter-observer variability2012In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, no 9, p. 966-972Article in journal (Refereed)
    Abstract [en]

    Background

    Unlike other solid organ transplants, pancreas allografts can undergo a substantial decrease in baseline volume after transplantation. This phenomenon has not been well characterized, as there are insufficient data on reliable and reproducible volume assessments. We hypothesized that characterization of pancreatic volume by means of computed tomography (CT) could be a useful method for clinical follow-up in pancreas transplant patients.

    Purpose

    To evaluate the feasibility and reliability of pancreatic volume assessment using CT scan in transplanted patients.

    Material and Methods

    CT examinations were performed on 21 consecutive patients undergoing pancreas transplantation. Volume measurements were carried out by two observers tracing the pancreatic contours in all slices. The observers performed the measurements twice for each patient. Differences in volume measurement were used to evaluate intra- and inter-observer variability.

    Results

    The intra-observer variability for the pancreatic volume measurements of Observers 1 and 2 was found to be in almost perfect agreement, with an intraclass correlation coefficient (ICC) of 0.90 (0.77-0.96) and 0.99 (0.98-1.0), respectively. Regarding inter-observer validity, the ICCs for the first and second measurements were 0.90 (range, 0.77-0.96) and 0.95 (range, 0.85-0.98), respectively.

    Conclusion

    CT volumetry is a reliable and reproducible method for measurement of transplanted pancreatic volume.

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