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  • 51.
    Lundqvist, Eva
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Segelsjö, Monica
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Andersson, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Transplantationskirurgi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Biglarnia, Ali-Reza
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Transplantationskirurgi.
    Measurement of transplanted pancreatic volume using computed tomography: reliability by intra- and inter-observer variability2012Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 9, s. 966-972Artikel i tidskrift (Refereegranskat)
    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.

  • 52.
    Lönnemark, Maria
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Oral contrast media in CT of the abdomen. A double-blind randomized study comparing an aqueous solution of amidotrizoate, an aqueous solution of iohexol and a viscous solution of iohexol1993Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 34, nr 5, s. 517-519Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In a double-blind randomized study 3 different preparations of oral contrast media for bowel opacification at CT of the abdomen have been compared. Plain aqueous solutions of amidotrizoate (9 mg I/ml) and iohexol (9 mg I/ml) were used as well as a preparation of iohexol (9 mg I/ml) to which a viscosity-increasing agent had been added. The distribution of the contrast media in the intestine, transit time and patient tolerance were evaluated. No significant differences were found regarding the distribution between the 3 preparations of contrast media, while there was a tendency for the transit time to be increased when the viscous preparation of iohexol was used. The aqueous solution of iohexol had the best taste, while the viscous preparation was markedly more difficult to drink. Aqueous solutions of iohexol and amidotrizoate were equal for bowel opacification and the addition of the viscosity-increasing agent did not improve the distribution of the contrast medium in the intestine.

  • 53. Mannerkoski, Minna
    et al.
    Heiskala, H.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Åberg, L.
    Sarna, S.
    Wirtavuori, K.
    Autti, Taina
    Brain magnetic resonance imaging of siblings from families with two or more children with learning or intellectual disabilities and need for full-time special education2009Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 4, s. 437-445Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Several factors are involved in determining a child's need for special education (SE). Thus, the value of brain magnetic resonance imaging (MRI) for subjects with learning and intellectual disabilities is uncertain. PURPOSE: To evaluate the usefulness of MRI in the diagnostic process of siblings with learning and intellectual disabilities and need for full-time SE. MATERIAL AND METHODS: Altogether, 119 siblings (mean age 11.9 years) from families in which two or more children attended/had previously attended full-time SE underwent prospective brain MRI. SE grouping included three levels, from specific learning disabilities (level 1) to global intellectual disabilities (level 3). Forty-three controls (level 0, mean age 12.0 years) attended mainstream education groups. Signal intensity and structural abnormalities were analyzed, and areas of the cerebrum, posterior fossa, corpus callosum, vermis and brain stem, and diameters of the corpus callosum were measured. In analyses, all area measurements were calculated in proportion to the total inner skull area. RESULTS: Abnormal finding in MRI was more common for siblings (n=62; 52%) in SE (58% for level 3; 49% for level 2; 35% for level 1) than for controls (n=13; 16%). The siblings showed enlarged supra- (P<0.001) and infratentorial (P=0.015) cerebrospinal fluid (CSF) spaces and mild corpus callosum abnormalities (P=0.003) compared to controls. Siblings in SE had smaller inner skull area than controls (P<0.001). Further, the relative area of the mesencephalon (P=0.027) and the diameter of the body of the corpus callosum (P=0.015) were significantly smaller than in controls. In binary logistic regression analysis, enlarged supratentorial CSF spaces increased the probability of SE (odds ratio 4.2; P=0.023). CONCLUSION: Subjects with learning and intellectual disabilities commonly have more MRI findings than controls. Enlarged supratentorial CSF spaces were a frequent finding in siblings in full-time SE.

  • 54. Meyer, Sofie
    et al.
    Valdemarsson, Stig
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Classification of pituitary growth hormone producing adenomas according to SIPAP: application in clinical practice2011Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, nr 7, s. 796-801Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background In 1997, the SIPAP classification was introduced, a guide designed for MRI, to characterize pituitary adenomas with emphasis on extrasellar extensions and impact on adjacent structures. To our knowledge no previous evaluation of the inter-observer agreement of the SIPAP classification has been performed.

    Purpose To evaluate the inter-observer agreement of the SIPAP classification.

    Material and Methods Sixty patients operated on for growth hormone producing pituitary adenomas at Lund University Hospital 1991-2007 had an assessable preoperative MRI scan. Forty-five of them also had an assessable postoperative MRI scan. The mean time between surgery and postoperative MRI scans was 11 months. Two observers evaluated all the MRI scans independently. The outcome of the evaluation is presented as the percentage of concordance in each of the evaluated directions and the degree of discrepancy for each of the directions evaluated.

    Results In 284 (79%) of 360 preoperative gradings both observers agreed completely. In 17 of the 60 preoperative MRI scans, both observers made identical assessments according to the SIPAP classification in all the six different directions of tumor extension. In 76 gradings the results differed between the observers. The difference was 1 grade (or less) in 69 cases. In 230 (85%) of 270 postoperative gradings the results were identical for both observers. In 18 of the 45 postoperative MRI scans, both observers made the same assessments according to the SIPAP classification in all the six different directions of tumor extension. In 40 gradings the results differed between the observers. The difference was 1 grade (or less) in all 40 cases.

    Conclusion We found a relatively high inter-observer agreement both pre- and postoperatively, supporting the usefulness and easy applicability of the SIPAP system for grading of pituitary adenomas pre- as well as postoperatively.

  • 55.
    Milosavljevic, Jugoslav
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Lindqvist, Ulla Ruth Kristina
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Elvin, Anders
    Ultrasound and power Doppler evaluation of the hand and wrist in patients with psoriatic arthritis2005Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, nr 4, s. 374-385Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To evaluate the ability of high-resolution and power Doppler sonography in detecting joint and tendon abnormalities in patients with psoriatic arthritis (PsA) of the hands and wrists compared with clinical and radiological findings. MATERIAL AND METHODS: Thirty-six patients with psoriatic arthritis of the hands and wrists and 10 healthy controls were examined with ultrasound (US). The degree of synovial proliferation, tenosynovitis, presence of joint effusion as well as the vascularity of synovial tissue was estimated. US findings were scored using a newly devised scoring system. RESULTS: Thirty-two patients had articular synovial proliferation and/or tenosynovitis/ tendinitis or joint effusion in one or more joints according to US. Twenty-two patients had tendon changes; only five had joint effusion. The synovial, Doppler, and total articular-teno scores were all significantly correlated to the number of swollen joints. The scores, however, did not correlate to other clinical or laboratory measurements of disease activity. CONCLUSION: US proved effective in demonstrating PsA involvement of the hands and wrists and was more sensitive than clinical examination in detecting pathology. Long-term follow-up studies are needed to evaluate whether this can change the traditional approach for assessing involvement of joints and tendons in PsA.

  • 56.
    Nylander, Ruta
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Fahlström, Markus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Rostrup, Egill
    Kullberg, Joel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Damangir, Soheil
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Lind, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Kardiovaskulär epidemiologi.
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Quantitative and qualitative MRI evaluation of cerebral small vessel disease in an elderly population: a longitudinal study2018Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 59, nr 5, s. 612-618Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background Cerebral white matter hyperintensities (WMHs), lacunes, and microbleeds are seen on magnetic resonance imaging (MRI) in small vessel disease (SVD). Purpose To assess SVD on MRI and its evolution over five years in an elderly population and to investigate whether relative cerebral blood flow (rCBF) at baseline was related to the progression of white matter (WM) lesions. Material and Methods In a population-based study, 406 participants aged 75 years underwent morphological MRI of the brain and 252 of them again at age 80 years. At age 75 years, a perfusion scan was also done. WMHs were evaluated qualitatively (visual scoring) and quantitatively (CASCADE software). Lacunes and microbleeds were counted. Results A significant progression of the WMH score and WMH volume occurred over five years ( P < 0.0001). New lacunes were seen in 10%. Participants with new lacunes at age 80 years showed a more pronounced increase in WMHs (P < 0.0001). Microbleeds were present in 14% at age 75 years. The visual WMH score was significantly associated with the presence of microbleeds ( P < 0.0001). There was no relationship between total WM rCBF and WMH volume at age 75 years, and no significant associations between regional or total rCBF at age 75 years and changes in WMH volume over five years. The total WM and GM volume decreased significantly between the ages of 75 and 80 years ( P < 0.0001). Conclusion MRI manifestations of SVD progressed over five years in an elderly population (age range = 75-80 years). rCBF was not associated with WMH volume or progression of WMH volume.

  • 57.
    Palm, Fredrik
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Carlsson, Per-Ola
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Hansell, Peter
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Nygren, Anders
    Hellberg, Olof
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Liss, Per
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Altered response in renal blood flow and oxygen tension to contrast media in diabetic rats2003Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, nr 3, s. 347-53Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To investigate the effect of the contrast medium (CM) iopromide on renal microcirculation and oxygen tension in non-diabetic control and streptozotocin-diabetic Wistar Furth rats. MATERIALS AND METHODS: Oxygen tension was measured with Clark-type microelectrodes and blood flow with laser-Doppler flow probes. In order to differentiate between an acutely increased blood glucose concentration and a long-term diabetic state, some of the non-diabetic control rats were intravenously infused with glucose. RESULTS: CM decreased the medullary oxygen tension in control (non-diabetic normoglycemic) rats ( approximately 35%) but not in diabetic rats. Medullary blood flow in control rats increased after CM administration and remained elevated, while it was unchanged in the diabetic rats. In response to CM, glucose-infused control rats responded similarly to control animals in medullary oxygen tension, but similarly to diabetic rats in medullary blood flow. Contrary to in control rats, medullary oxygen tension was unchanged in diabetic animals after CM administration. CONCLUSION: Streptozotocin-diabetic rats have an altered response to intravenous injection of the CM iopromide compared to non-diabetic rats. The unaltered medullary oxygen tension, seen in the diabetic group after injection of CM, suggests that non-hemodynamic mechanisms are responsible for the increased frequency of renal failure commonly seen among diabetic patients.

  • 58.
    Penno, Eva
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Johnsson, C
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Transplantationskirurgi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Macrophage uptake of ultra-small iron oxide particles for magnetic resonance imaging in experimental acute cardiac transplant rejection2006Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, nr 3, s. 264-271Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To discriminate between acutely rejecting and non-rejecting transplanted hearts using a blood pool contrast agent and T2* magnetic resonance imaging (MRI) in a clinical 1.5T scanner.

    MATERIAL AND METHODS:

    Allogeneic and syngeneic heterotopic heart transplantations were performed in rats. One allogeneic and one syngeneic group each received either the ultra-small iron oxide particle (USPIO), at two different doses, or no contrast agent at all. MRI was performed on postoperative day 6. Immediately after the MR scanning, contrast agent was injected and a further MRI was done 24 h later. Change in T2* was calculated.

    RESULTS:

    No significant difference in change in T2* could be seen between rejecting and non-rejecting grafts in either of the doses, or in the control groups. There was a difference between the allogeneic group that received the higher contrast agent dose and the allogeneic group that did not receive any contrast agent at all.

    CONCLUSION:

    In our rat model, measurements of T2* after myocardial macrophage uptake of AMI-227 in a clinical 1.5T scanner were not useful for the diagnosis of acute rejection.

  • 59.
    Radecka, Eva
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Brekkan, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Urologkirurgi.
    Juhlin, Claes
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Nilsson, L
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Thoraxkirurgi.
    Sundin, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    An unusual case of tumor thrombus in the inferior vena cava: A case report2003Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, nr 2, s. 160-161Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adrenal cortical carcinoma (ACC) is a rare malignancy. Patients present either with a functional tumor or secondary to mass effect. In non-functioning tumors, the tumor size often exceeds 5 cm by the time of diagnosis, and tumor thrombus can occur. We report on a case of a small non-functioning ACC causing a large tumor thrombus in the inferior vena cava.

  • 60.
    Radecka, Eva
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Magnusson, Mats
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Magnusson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Survival time and period of catheterisation in patients treated with percutaneous nephrostomy for urinary obstruction due to malignancy2006Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 47, nr 3, s. 328-331Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To assess patient mortality and survival time, period of catheterization, and indications for percutaneous nephrostomy (PCN) withdrawal in patients treated with PCN for urinary obstruction due to malignancy.

    MATERIAL AND METHODS:

    A retrospective analysis of 151 patients treated with 257 PCNs in a 5-year period was performed. Data on survival time, duration of catheterization, and clinical end-points for PCN treatment were collected.

    RESULTS:

    The median survival time of the patients was 255 days, while median catheterization time was 62 days. The majority of patients (84) died with the catheter. Indications for PCN withdrawal were surgery, stent treatment, catheter displacement, and response to medical treatment.

    CONCLUSION:

    The majority of patients with malignancy treated with PCN have advanced disease and short life expectancy. Factors such as diagnosis, prognosis, economy, and the patient's preference influence the choice of urinary diversion method. However, PCN should be considered in patients with malignancy on grounds of safety and low cost.

  • 61.
    Raininko, Raili
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Mattsson, Peter
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurologi.
    Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time 1H magnetic resonance spectroscopy (MRS) study2010Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 51, nr 3, s. 309-315Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Age- and sex-related changes of metabolites in healthy adult brains have been examined with different (1)H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T(1) and T(2) relaxation effects and makes it possible to measure metabolites with short T(2) relaxation times. PURPOSE: To examine the effect of age on the metabolite concentrations measured by (1)H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE). MATERIAL AND METHODS: Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification. Results: Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations. CONCLUSION: The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on (1)H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each (1)H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people.

  • 62. Ramgren, Birgitta
    et al.
    Siemund, Roger
    Nilsson, Ola G
    Höglund, Peter
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Abul-Kasim, Kasim
    Björkman-Burtscher, Isabella M
    CT angiography in non-traumatic subarachnoid hemorrhage: the importance of arterial attenuation for the detection of intracranial aneurysms2015Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 56, nr 10, s. 1248-1255Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Computed tomography angiography (CTA) is today the primary method for the detection of intracranial aneurysms. The technique has evolved considerably during the last decade, and it is important to establish criteria for high image quality, especially with regard to improving the diagnosis of small aneurysms.

    PURPOSE: To evaluate diagnostic accuracy and image quality by arterial attenuation of CTA in patients with non-traumatic subarachnoid hemorrhage (SAH).

    MATERIAL AND METHODS: Between 2005 and 2011, CTA and digital subtraction angiography (DSA) were performed in 326 patients with non-traumatic SAH. Sensitivity and specificity for aneurysm detection were evaluated per patient, per aneurysm, and per ruptured aneurysm. The image quality of CTA was evaluated by arterial attenuation measurements (mean Hounsfield units [HU]) in the internal carotid artery (ICA).

    RESULTS: In all, 285 aneurysms in 235 patients were detected by DSA, 19 aneurysms were missed on CTA, and 223 aneurysms were classified as ruptured. In 91 patients, no aneurysm was found. Correct diagnosis with CTA was made in 28 patients with perimesencephalic hemorrhage. Sensitivity and specificity (95% confidence interval) calculated per patient were 91.6% (87.3-94.9) and 87.9% (79.8-93.6), respectively, per aneurysm 93.3% (89.7-95.9) and 88% (79.9-93.6), and per ruptured aneurysm 94.9% (91.3-97.3) and 96.7% (90.7-99.3). Arterial attenuation (in HU) in CTA revealing true positive ruptured aneurysms and true negative aneurysms (mean 535 ± 110 HU) differed significantly (P = 0.02) from false negative ruptured aneurysms (mean 424 ± 30 HU).

    CONCLUSION: CTA has high sensitivity and specificity for the detection of ruptured aneurysms. The sensitivity is related to arterial attenuation in the ICA.

  • 63.
    Rasmussen, Ib Christian
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Gastrointestinalkirurgi.
    Dahlstrand, Ursula
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Kolorektalkirurgi.
    Sandblom, Gabriel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Gastrointestinalkirurgi.
    Eriksson, Lars-Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Nyman, Rickard
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Fractures of self-expanding metallic stents in periampullary malignant biliary obstruction2009Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 7, s. 730-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Self-expanding metallic stents are widely used for relieving biliary duct obstruction in patients with unresectable periampullary malignancies. However, only a few studies have assessed the occurrence of fractures in these stents. PURPOSE: To determine the prevalence and significance of stent fracture after placement of self-expanding metallic stents for periampullary malignant biliary obstruction. MATERIAL AND METHODS: Over a 5-year period, 48 patients underwent placement of self-expanding metallic stents for periampullary malignant biliary obstructions. Stents were introduced 2-6 weeks after a percutaneous transhepatic biliary decompression. The medical records and relevant images were reviewed for stent patency, stent fracture, type of stent, and stent-related complications. RESULTS: Stent fracture was detected in four of the 48 patients (8%): in one patient at 1 month and in three patients between 10 and 21 months after stenting. All four fractures involved one type of nitinol stent used in 38 patients. In one of the patients, fracture was complicated by life-threatening gastrointestinal bleeding. The mean survival time for all patients was 251 days (standard deviation [SD]+/-275 days) and the mean overall patency time for all stents was 187 days (SD+/-205 days). CONCLUSION: Stent fracture occurs after placement of self-expanding nitinol stents for periampullary malignant biliary obstruction. The low reported incidence of this complication may be due to a lack of awareness of and difficulty in detecting stent fracture. Fracture should be considered as a possible contributing factor in recurrent biliary obstruction after self-expanding metallic stent insertion.

  • 64.
    Ripoll, Montserrat Alemany
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Siösteen, B.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för patologi.
    Hartman, M.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för patologi.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    MR detectability and appearance of small experimental intracranial hematomas at 1.5 T and 0.5 T: A 6-7-month follow-up study2003Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 44, nr 2, s. 199-205Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To investigate the detectability and appearance of small experimental intracranial hemorrhages on MR at 0.5 T and 1.5 T in a long-term follow-up. MATERIAL AND METHODS: Autologous blood (1 ml) was injected into the brain of 7 rabbits to create intraparenchymal hematomas. The injected blood leaked partially into the cerebrospinal fluid (CSF) spaces. MR imaging at 0.5 T and 1.5 T were performed immediately before and after hematoma creation, at 2 weeks and monthly up to 6 or 7 months using T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. RESULTS: Blood was detected both in the brain and in the CSF spaces of all animals during the first hours after hematoma creation at 1.5 T. In the last examination after 6-7 months, the T2*-w GE sequences still showed residues of the intraparenchymal hematomas in all the rabbits at 1.5 T, but the signal pattern was not specific for the age of the hematomas. SE and FLAIR sequences were insensitive. The histopathology revealed iron deposits in all brains. CONCLUSION: Residues of small intraparenchymal hematomas can be seen for months with T2*-w GE sequences on brain MR imaging at 1.5 T. The age of the microhematomas cannot be estimated with MR imaging.

  • 65.
    Rodriguez, M
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Rehn, S M
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Nyman, Rickard S
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Sundström, J C
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för patologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Glimelius, Bengt L
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    CT in malignancy grading and prognostic prediction of non-Hodgkin's lymphoma1999Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 40, nr 2, s. 191-197Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    The presence of tumor inhomogeneities in MR images of non-Hodgkin's lymphoma (NHL) provides information about malignancy grade and prognosis. The aim of this study was to determine whether CT images are also informative in these respects.

    MATERIAL AND METHODS:

    Sixty-three CT examinations in patients with NHL (32 high-grade and 31 low-grade tumors) were reviewed retrospectively by two senior radiologists. The tumor patterns were classified subjectively as homogeneous, slightly inhomogeneous or severely inhomogeneous and their relations to malignancy grade, clinical characteristics and prognosis were determined.

    RESULTS:

    Sixteen out of 17 patients with a severely inhomogeneous tumor pattern had high-grade NHL tumors while 21 out of 29 patients with a homogeneous tumor appearance had low-grade NHL tumors. Among chemotherapy-treated patients, those with the highest degree of inhomogeneity had a significantly worse prognosis (9 out of 11 patients died). This relationship was not found in patients treated with radiotherapy.

    CONCLUSION:

    A severely inhomogeneous tumor pattern on CT images was found to be associated with a high malignancy grade in NHL. This CT pattern was also compatible with a poor prognosis in patients treated with chemotherapy.

  • 66. Rollven, Erik
    et al.
    Holm, Torbjorn
    Glimelius, Bengt
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för onkologi.
    Lorinc, Esther
    Blomqvist, Lennart
    Potentials of high resolution magnetic resonance imaging versus computed tomography for preoperative local staging of colon cancer2013Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 54, nr 7, s. 722-730Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Preoperative identification of locally advanced colon cancer is of importance in order toproperly plan treatment. Purpose: To study high resolution T2-weighted magnetic resonance imaging (MRI) versus computed tomography (CT) for preoperative staging of colon cancer with surgery and histopathology as reference standard. Material and Methods: Twenty-eight patients with a total of 29 tumors were included. Patients were examined on a 1.5 T MR unit using a phased array body coil. T2 turbo spin-echo high resolution sequences were obtained in a coronal, transverse, and perpendicular plane to the long axis of the colon at the site of the tumor. Contrast-enhanced CT was performed using a protocol for metastasis staging. The examinations were independently evaluated by two gastrointestinal radiologists using criteria adapted to imaging for prediction of T-stage, N-stage, and extramural venous invasion. Based on the T-stage, tumors were divided in to locally advanced (T3cd-T4) and not locally advanced (T1-T3ab). Surgical and histopathological findings served as reference standard. Results: Using MRI, T-stage, N-stage, and extramural venous invasion were correctly predicted for each observer in 90% and 93%, 72% and 69%, and 82% and 78% of cases, respectively. With CT the corresponding results were 79% and 76%, 72% and 72%, 78% and 67%. For MRI inter-observer agreements (Kappa statistics) were 0.79, 0.10, and 0.76. For CT the corresponding results were 0.64, 0.66, and 0.22. Conclusion: Patients with locally advanced colon cancer, defined as tumor stage T3cd-T4, can be identified by both high resolution MRI and CT, even when CT is performed with a metastasis staging protocol. MRI may have an advantage, due to its high soft tissue discrimination, to identify certain prognostic factors such as T-stage and extramural venous invasion.

  • 67.
    Rosenqvist, Kerstin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning, Västerås.
    Ebeling Barbier, Charlotte
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Rorsman, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Gastroenterologi/hepatologi.
    Sangfelt, Per
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Gastroenterologi/hepatologi.
    Nyman, Rickard
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Treatment of acute portomesenteric venous thrombosis with thrombectomy through a transjugular intrahepatic portosystemic shunt: a single-center experience.2018Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 59, nr 8, s. 953-958Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Acute portomesenteric venous thrombosis (PMVT) is a potentially life-threatening condition and urgent treatment is required.

    Purpose: To retrospectively evaluate the efficacy and safety of treating acute PMVT by the creation of a transjugular intrahepatic portosystemic shunt (TIPS) followed by thrombectomy.

    Material and Methods: Six patients (all men, age range = 39-51 years) presenting with acute PMVT were treated with transjugular thrombectomy (TT) through a TIPS created in the same session. The intervention included iterated venography through the TIPS one to three times within the first week after diagnosis and repeated thrombectomy if needed (n = 5).

    Results: Recanalization was successful with persistent blood flow through the main superior mesenteric vein, portal vein, and TIPS in all six patients. Five patients were treated primarily with thrombectomy through a TIPS with clinical improvement. The final patient was initially treated with surgical thrombectomy and bowel resection. TIPS and TT was performed two days after surgery due to re-thrombosis but the patient deteriorated and died of multi-organ failure. Procedure-related complications were transient hematuria (n = 3) and transient encephalopathy (n = 2). In-hospital time was <14 days in four of the five patients with primary TIPS and TT. No sign of re-thrombosis was noted during follow-up (mean = 18 months, range = 8-28 months).

    Conclusion: Thrombectomy through a TIPS is feasible and can be effective in recanalization and symptom-relief in acute PMVT.

  • 68.
    Rosenqvist, Kerstin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Eriksson, Lars-Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Rorsman, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Gastroenterologi/hepatologi.
    Sangfelt, Per
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Gastroenterologi/hepatologi.
    Nyman, Rickard
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Endovascular treatment of acute and chronic portal vein thrombosis in patients with cirrhotic and non-cirrhotic liver2016Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, nr 5, s. 572-579Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Treatment of patients with portal vein thrombosis (PVT) differs due to different etiology and wide range of symptoms but certain patients seems to benefit from endovascular intervention.

    PURPOSE: To assess the safety and efficiency of endovascular treatment of acute and chronic PVT in patients with cirrhotic and non-cirrhotic liver.

    MATERIAL AND METHODS: Twenty-one patients with PVT treated with an endovascular procedure in 2002-2013 were studied retrospectively. Data on etiology, onset and extension of thrombus, presenting symptoms, methods of intervention, portal pressure gradients, complications, recurrence of symptoms, re-interventions, clinical status at latest follow-up, and survival were collected.

    RESULTS: Four non-cirrhotic patients with acute extensive PVT and bowel ischemia were treated with local thrombolysis, in three combined with placement of a transjugular intrahepatic portosystemic shunt (TIPS) placement. Three recovered and have survived more than 6 years. In six non-cirrhotic patients with chronic PVT and acute or threatening variceal bleeding recanalization and TIPS were successful in three and failed in three. Eleven cirrhotic patients with PVT and variceal bleeding or refractory ascites were successfully treated with recanalization and TIPS. Re-intervention was performed in five of these patients and five patients died, three within 12 months of intervention. Four cirrhotic patients had episodes of shunt-related encephalopathy and three had variceal re-bleeding.

    CONCLUSION: TIPS was found to be effective in reducing portal hypertension in patients with PVT. In patients with extensive PVT and bowel ischemia treatment with TIPS combined with thrombolysis should be considered.

  • 69.
    Rossitti, Sandro
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Hidden compartments in intracranial arteriovenous malformation1997Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 5, s. 922-3Artikel i tidskrift (Refereegranskat)
  • 70. Smedby, O
    et al.
    Weis, J
    Timing adjustment in gadolinium MR angiography by raw data recombination. Technical note.1999Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 40, nr 4, s. 462-4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To solve the problem of injection timing in gadolinium MR angiography, a simple procedure is proposed which allows the acquisition interval to be chosen after injection. Starting simultaneously with the injection, several consecutive acquisitions are made, after which raw data acquired in a contiguous interval with a variable starting time are recombined to one data set, which is then used for delayed image reconstruction.

  • 71. Smedby, Örjan
    et al.
    Weis, Jan
    Timing adjustment in gadolinium MRA by raw data rearrangement1999Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 40, s. 462-464Artikel i tidskrift (Refereegranskat)
  • 72. Soljanlahti, Sami
    et al.
    Raininko, Raili
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Hyttinen, L.
    Lauerma, Kirsi
    Keto, Pekka
    Vuorio, Alpo F.
    Autti, Taina
    Statin-treated familial hypercholesterolemia patients with coronary heart disease and pronounced atherosclerosis do not have more brain lesions than healthy controls in later middle age2007Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 8, s. 894-899Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Clinically silent brain lesions detected with magnetic resonance imaging (MRI) are associated with increased risk for stroke, while stroke risk is controversial in familial hypercholesterolemia (FH). PURPOSE: To determine whether the occurrence and size of clinically silent brain lesions in FH patients with coronary heart disease (CHD) is higher than in neurologically healthy controls without CHD. MATERIAL AND METHODS: Brain MRI (1.5T) was performed on 19 DNA-test-verified FH patients with CHD and on 29 cardiovascularly and neurologically healthy controls, all aged 48 to 64 years. All patients were on cardiovascular medication. Intracranial arteries were evaluated by MR angiography. Infarcts, including lacunas, and white matter T2 hyperintensities (WMHI), considered as signs of small vessel disease, were recorded. A venous blood sample was obtained for assessment of risk factors. Carotid and femoral intima-media thicknesses (IMT), assessed with ultrasound, were indicators of overall atherosclerosis. RESULTS: On intracranial MR angiography, three patients showed irregular walls or narrowed lumens in intracranial carotid arteries. No silent infarcts appeared, and no differences in numbers or sizes of WMHIs between groups were recorded. Patients had greater carotid and femoral IMTs, and a greater number of carotid and femoral plaques. Cholesterol-years score, level of low-density lipoprotein (LDL) cholesterol, and level of high-sensitivity C-reactive protein (hsCRP) of the FH-North Karelia patients were higher than those of the controls, while the level of high-density lipoprotein (HDL) cholesterol in controls was higher. CONCLUSION: FH patients with CHD and adequate cardiovascular risk-factor treatment showed no difference in the amount or size of clinically silent brain lesions compared to controls, despite patients' more severe atherosclerosis.

  • 73. Sugimoto, Eiichi
    et al.
    Lörelius, Lars-Erik
    Eriksson, Barbro
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Öberg, Kjell
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Midgut Carcinoid Tumours CT appearance1995Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, nr 4, s. 367-371Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CT was performed on 80 patients referred for staging and treatment of histologically verified midgut carcinoid tumours. In 17 cases (21%) CT was normal in spite of biochemical signs of tumour (increased U-5-HIAA). The most common finding was liver metastases in 54/80 (68%) of patients. Mesenteric metastases, usually as a soft tissue mass at the mesenteric root, were found in 17/80 (21%). Retroperitoneal adenopathy was found in 19/80 (24%). During a follow-up time of 3 months to 10 years (median 3 years) 445 additional CT examinations were performed on 77 patients. In 39 of these, progressive disease (new lesions) was found after a median time of 15 months (range 3 months-6.5 years). CT is poor in detecting primary carcinoid tumours but helpful in evaluating the extent of tumour spread before surgical exploration and during follow-up once the diagnosis has been established.

  • 74. Svalkvist, A.
    et al.
    Johnsson, A. A.
    Vikgren, J.
    Hakansson, M.
    Ullman, Gustaf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Beräknings- och systembiologi.
    Boijsen, M.
    Fisichella, V.
    Flinck, A.
    Molnar, D.
    Mansson, L. G.
    Bath, M.
    Evaluation of an improved method of simulating lung nodules in chest tomosynthesis2012Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 8, s. 874-884Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Simulated pathology is a valuable complement to clinical images in studies aiming at evaluating an imaging technique. In order for a study using simulated pathology to be valid, it is important that the simulated pathology in a realistic way reflect the characteristics of real pathology. Purpose: To perform a thorough evaluation of a nodule simulation method for chest tomosynthesis, comparing the detection rate and appearance of the artificial nodules with those of real nodules in an observer performance experiment. Material and Methods: A cohort consisting of 64 patients, 38 patients with a total of 129 identified pulmonary nodules and 26 patients without identified pulmonary nodules, was used in the study. Simulated nodules, matching the real clinically found pulmonary nodules by size, attenuation, and location, were created and randomly inserted into the tomosynthesis section images of the patients. Three thoracic radiologists and one radiology resident reviewed the images in an observer performance study divided into two parts. The first part included nodule detection and the second part included rating of the visual appearance of the nodules. The results were evaluated using a modified receiver-operating characteristic (ROC) analysis. Results: The sensitivities for real and simulated nodules were comparable, as the area under the modified ROC curve (AUC) was close to 0.5 for all observers (range, 0.43-0.55). Even though the ratings of visual appearance for real and simulated nodules overlapped considerably, the statistical analysis revealed that the observers to were able to separate simulated nodules from real nodules (AUC values range 0.70-0.74). Conclusion: The simulation method can be used to create artificial lung nodules that have similar detectability as real nodules in chest tomosynthesis, although experienced thoracic radiologists may be able to distinguish them from real nodules.

  • 75.
    Themudo, Raquel Espregueira
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Ebeling Barbier, Charlotte
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Lind, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Bjerner, Tomas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Signal Intensity of Myocardial Scars at Delayed-enhanced MRI2009Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 6, s. 652-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Traditionally, unrecognized myocardial infarction (UMI) is defined as the appearance, in a non-acute setting, of a new diagnostic Q wave. In the recent past, delayed-enhanced magnetic resonance imaging (DE-MRI) has provided a new imaging method for evaluating myocardial viability and to detect myocardial scars. Purpose: To investigate differences in tissue characteristics between UMI and recognized myocardial infarction (RMI) scars, by assessing the signal intensity (SI) detected by DE-MRI. Material and Methods: A randomized subgroup of 259 subjects from the Prospective Investigation of the Vasculature of Uppsala Seniors (PIVUS) study was submitted to cardiac magnetic resonance imaging (MRI). DE-MRI-detected myocardial scars were divided in two groups, UMI and RMI, according to the hospital medical records. The scars detected by DE-MRI were analyzed by measuring SI ratio of scar tissue to normal myocardium. Results: The mean SI ratio in the UMI group (4.5+/-3.0, mean+/-SD) was lower than in the RMI group 8.9+/-5.1 (P-value = 0.001). This difference was still significant (P <0.0001) after adjustment for gender, body mass index, time of image acquisition after gadolinium administration, scar transmurality, or total myocardial infarction mass. Conclusion: The difference in the SI ratio of the scars between the two groups most likely reflects a different contrast distribution volume of the tissues, which might indicate that UMI and RMI tissues diverge in tissue composition.

  • 76. Thomsen, H
    et al.
    Steffensen, E
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas2012Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, nr 1, s. 95-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Perfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies.PurposeTo assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC-MRI using two different regions for normalization and two different measurement approaches.Material and

    Methods

    Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and rCBV maps, with contralateral normal appearing white matter and cerebellum as reference regions. Larger ROIs were drawn for histogram analyses. The type and grade of the gliomas were obtained by histopathology. Statistical comparison was made between diffuse astrocytomas, anaplastic astrocytomas, and glioblastomas.

    Results

    rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r = 0.60) and to the cerebellum (r = 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated (0.61 < r < 0.93), whereas for kurtosis and peak height, the correlation coefficient was about 0.3 when comparing rCBF and rCBV values for the same reference region. Neither rCBF nor rCBV quantification provided a statistically significant difference between the three types of gliomas. However, both rCBF and rCBV tended to increase with tumor grade and to be lower in patients who had undergone resection/treatment.

    Conclusion

    rCBF measurements normalized to white matter or cerebellum are comparable with the established rCBV measurements used for the clinical evaluation of cerebral gliomas.

  • 77. Thorstensen, Örn
    et al.
    Isberg, B.
    Jorulf, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Svahn, U.
    Westman, L.
    Venizelos, N.
    Nennesmo, I.
    Detection of small implanted tumors growing during repeated magnetic resonance imaging of the rabbit liver: application of an interpretation model2004Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 45, nr 5, s. 547-555Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To apply experimentally and further develop a new image interpretation model based on repeated imaging and aimed at improving assessments of technical efficacy and diagnostic accuracy in the detection of small lesions. MATERIAL AND METHODS: VX2 carcinoma was implanted in the liver of 14 rabbits as two 1.1-1.7 mm3 cores. Magnetic resonance imaging was performed before and 4 days after implantation and then every second day up to the 14th to 20th day. One T2-weighted sequence (TSE T2) and three T1-weighted sequences (SE T1, GE T1, and TFL T1) were used. Interpretation was performed stepwise: three readers independently interpreted image sequences chronologically (step 1). Tumors were included at the last examination (step 2). By concurrent interpretation of repeated examinations, the earliest day at which tumors became visible and tumor size were recorded (step 3). Records were corrected (step 4) and autopsy was performed (step 5). Two procedures for use in calculating repeated detection rates of tumors with different magnetic resonance imaging sequences are presented and discussed. RESULTS: Of 40 macroscopic tumors, 34 were included. They were mainly small (size range SE T1: 1-3mm, TSE T2: 1.5-5 mm) when they became visible as determined at step 3, which was consistently earlier than observed at step 1. TSE T2, SE T1, and GE T1 did not differ significantly regarding earliest day of detection (step 3), while TFL T1 revealed the tumors later. The initial repeated detection rates were higher with TSE T2 than with the other sequences. Frequency of false positives varied over time, indicating fluctuating criteria for reporting tumors. CONCLUSION: A theoretical image interpretation model previously described proved to be applicable for detection of experimental liver tumors. The model was improved by introducing calculations of repeated detection rates for initial image interpretation using an imaging reference standard.

  • 78.
    Wang, C
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ekholm, S
    Fagertun, H
    Hellström, M
    Hemmingsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Holtås, S
    Isberg, B
    Jonnson, E
    Lönnemark-Magnusson, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    McGill, S
    Wallengren, N O
    Westman, L
    Diagnostic efficacy of MnDPDP in MR imaging of the liver: A phase III multicentre study1997Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 4 Pt 2, s. 643-649Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To assess the diagnostic efficacy, safety and tolerability of mangafodipir trisodium (MnDPDP, Teslascan) in MR imaging of the liver.

    MATERIAL AND METHODS:

    Eighty-two patients from 4 centres underwent MR imaging with pre-contrast sequences including T1-weighted SE and GRE, and T2-weighted turbo SE sequences. MnDPDP at a dose of 5 mumol/kg b.w. was administered by slow i.v. infusion, and 20-60 min after infusion the T1-weighted SE and GRE sequences were repeated. Diagnostic efficacy was evaluated by counting the number of lesions and by evaluating whether more information for lesion characterisation was available in post-contrast images. Safety and tolerability were assessed by recording adverse events and infusion-related discomfort.

    RESULTS:

    Significantly more lesions were found in MnDPDP-enhanced T1-weighted SE and GRE images than in unenhanced images of the same sequences. More lesions were also found in these images compared with T2-weighted images at a level of marginal significance. More information was obtained from MnDPDP-enhanced images in 40 cases. Mild to moderate adverse events were experienced by 17% of the patients.

    CONCLUSION:

    MnDPDP-enhanced images can improve lesion detection in the liver and are helpful for lesion characterisation. To obtain optimal diagnostic information of liver lesions T2-weighted images are also valuable. MnDPDP is a safe contrast agent for MR imaging of liver lesions.

  • 79.
    Wang, C
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Gordon, P B
    Hustvedt, S O
    Grant, D
    Sterud, A T
    Martinsen, I
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Hemmingsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    MR imaging properties and pharmacokinetics of MnDPDP in healthy volunteers1997Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 4 Pt 2, s. 665-676Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    Thirteen male volunteers were studied to evaluate the MR imaging properties and pharmacokinetics of 10 mM mangafodipir trisodium infusion (MnDPDP, Teslascan).

    MATERIAL AND METHODS:

    Doses of 5 and 10 mumol/kg b.w. were administered by bolus injection (< 1 min) to 5 subjects, and by infusion (20 min) to 8 subjects, with a 3-week wash-out between doses. Infusion subjects underwent MR imaging.

    RESULTS:

    At 1 h after infusion, the plasma concentration of Mn was reduced to approximately 15% of the maximum value. Fifteen to 20% of Mn was recovered in the urine, and 50-60% was recovered in the faeces. The rapid initial plasma clearance of Mn is consistent with both rapid tissue uptake and rapid renal elimination. Increases in signal intensity were apparent on T1-weighted images of the liver, pancreas, spleen, renal cortex and the renal medulla, but not in regions of the brain protected by an intact blood-brain barrier. Increases were seen in the choroid plexus and pituitary. Contrast-related adverse events, only flushing of moderate intensity, occurred in bolus injection subjects.

    CONCLUSION:

    At 5 and 10 mumol/kg, mangafodipir produces relatively long-lasting enhancement of several abdominal organs, including the liver, pancreas and kidney.

  • 80.
    Wang, Chen
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Sundín, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ericsson, A
    Bach-Gansmo, T
    Hemmingsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Dysprosium-enhanced MR imaging for tumor tissue characterization: an experimental study in a human xenograft model1997Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 38, nr 2, s. 281-286Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To evaluate dysprosium-enhanced MR imaging for differentiation between morphologically intact and necrotic tumor tissue in a tumor model.

    MATERIAL AND METHODS:

    A human colon carcinoma was transplanted subcutaneously into 9 nude (immunodeprived) rats. MR imaging was performed before and after injection of the dysprosium agent Dy-DTPA-BMA. T1-, T2- and T2*-weighted sequences were acquired. The tumors were dissected, histological sections were prepared, and compared with corresponding MR images.

    RESULTS:

    In intact tissue, the MR signal intensity in the T2- and T2*-weighted images decreased after Dy injection and the delineation of the intact regions were sharp and corresponded well to the gross histological sections.

    CONCLUSION:

    Dy-enhanced MR imaging facilitated the differentiation between intact and necrotic tumor tissue.

  • 81.
    Wiklund, E
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Koskinen, S K
    Linder, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Kolorektalkirurgi.
    Åslund, P-E
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Eklöf, Hampus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Whole body computed tomography for trauma patients in the Nordic countries 2014: survey shows significant differences and a need for common guidelines2016Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, nr 6, s. 750-757Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Whole body computed tomography in trauma (WBCTT) is a standardized CT examination of trauma patients. It has a relatively high radiation dose. Therefore, well-defined clinical indications and imaging protocols are needed. This information regarding Nordic countries is limited.

    PURPOSE: To identify Nordic countries' WBCTT imaging protocols, radiation dose, and integration in trauma care, and to inquire about the need for common Nordic guidelines.

    MATERIAL AND METHODS: A survey with 23 multiple choice questions or free text responses was sent to 95 hospitals and 10 trauma centers in and outside the Nordic region, respectively. The questions were defined and the hospitals selected in collaboration with board members of "Nordic Forum for Trauma and Emergency Radiology" (www.nordictraumarad.com).

    RESULTS: Two Nordic hospitals declined to take part in the survey. Out of the remaining 93 Nordic hospitals, 56 completed the questionnaire. Arterial visualization is routine in major trauma centers but only in 50% of the Nordic hospitals. The CT scanner is located within 50 m of the emergency department in all non-Nordic trauma centers but only in 60% of Nordic hospitals. Radiation dose for WBCTT is in the range of 900-3600 mGy × cm. Of the 56 responding Nordic hospitals, 84% have official guidelines for WBCTT. Eighty-nine percent of the responders state there is a need for common guidelines.

    CONCLUSION: Scanning protocols, radiation doses, and routines differ significantly between hospitals and trauma centers. Guideline for WBCTT is presently defined locally in most Nordic hospitals. There is an interest in most Nordic hospitals to endorse new and common guidelines for WBCTT.

  • 82.
    Wikström, Johan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Bjornerud, Atle
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    McGill, S.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Venous saturation slab causes overestimation of stenosis length in two-dimensional time-of-flight magnetic resonance angiography2009Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 50, nr 1, s. 55-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: The use of downstream saturation slabs in two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of the arterial system eliminates signal from regions with countercurrent flow, as seen in veins, but possibly also beyond arterial stenoses because of flow turbulence. PURPOSE: To investigate the contribution of a downstream saturation slab to signal intensity (SI) loss beyond stenoses at 2D TOF MRA. MATERIAL AND METHODS: 2D TOF MRA was performed on a bifurcation phantom with a tight stenosis at 1.5T during pulsatile flow. Qualitative and quantitative evaluations of stenosis delineation were performed with different echo times (TE) (3.7 or 7.0 ms), spatial resolution (1 x 1 x 1 or 1 x 1 x 5 mm(3)), and with or without a downstream saturation slab. For reference, a high-resolution contrast-enhanced sequence without flow was obtained. RESULTS: The downstream saturation slab caused severe signal loss immediately distal to the stenosis, causing overestimation of stenosis length. This region corresponded with a region of poststenotic flow jet, where turbulence is expected. With increase in TE, there was some increased SI loss at the level of maximum stenosis. A lower spatial resolution resulted in overall poorer delineation of the stenosis. CONCLUSION: Using clinically relevant sequence parameters, the use of a downstream saturation slab at 2D TOF MRA was found to be a major contributor to signal loss in stenotic regions, which can result in an overestimation of stenosis length.

  • 83.
    Wikström, Johan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Hansen, Tomas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Lind, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Ankle brachial index <0.9 underestimates the prevalence of peripheral artery occlusive disease assessed with whole-body magnetic resonance angiography in the elderly2008Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 49, nr 2, s. 143-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. PURPOSE: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. MATERIAL AND METHODS: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. RESULTS: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one > or =50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a > or =50% stenosis in the pelvic or leg arteries. CONCLUSION: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population.

  • 84.
    Wikström, Johan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Karacagil, Sadettin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Correlation of femoral artery flow velocity waveform with ipsilateral iliac artery stenoses assessed with magnetic resonance imaging2007Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 48, nr 4, s. 422-430Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Magnetic resonance (MR) permits quantitative flow velocity measurements that could be used to detect changes in the curve profile downstream of a high-grade stenosis. Purpose: To assess whether MR flow measurements can be used to detect iliac artery stenoses. Material and Methods: Contrast-enhanced magnetic resonance angiography (MRA) and quantitative flow measurements in the lower aorta and proximal femoral arteries were performed in 29 patients with suspected iliac artery stenoses. Stenoses were graded into five degrees: 0%, 1-49%, 50-74%, 75-99%, and 100% diameter reduction. The femoral artery waveforms were evaluated qualitatively by two independent reviewers regarding peak systolic velocity (PSV), aortofemoral difference in time-to-peak (TTP), systolic acceleration (SA), curve-shape index (CSI), and the presence of an early diastolic flow reversal. The correlation between these parameters and the degree of stenosis was assessed. Results: A significant correlation with degree of stenosis was observed for the qualitative flow waveform evaluations, with a high degree of interobserver agreement (=0.84). A significant correlation was also found between degree of stenosis and PSV, TTP, SA, CSI, and presence of diastolic flow reversal. The flow velocity pattern, however, remained unchanged, both qualitatively and quantitatively, up to a stenosis degree of at least 75%. Conclusion: Iliac artery stenoses cause femoral artery flow waveform changes that can be detected with MRI, but only at high-grade levels.

  • 85.
    Wikström, Johan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Johansson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Rossitti, S.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi.
    Karacagil, Sadettin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    High-resolution carotid artery MRA: Comparison with fast dynamicac quistion and duplex ultrasound scanning2002Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 43, nr 3, s. 256-261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To determine whether the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) of the carotid arteries is improved by using a slow-injection, high-resolution technique.

    MATERIAL AND METHODS: In 22 patients suspected to have internal carotid artery (ICA) stenosis at duplex ultrasound scanning (DUS), CE-MRA was performed both with a fast, dynamic (8 s/phase) and with a slower, high-resolution technique (scan time 2:20 min).

    RESULTS: There was conformity between the CE-MRA techniques regarding the degree of stenosis in 34/40 extracranial ICAs. In 3/6 discrepant cases, short occlusions were seen with the fast dynamic technique, whereas both the high-resolution CE-MRA technique and DUS showed patent vessels. There was an overall tendency toward higher stenosis grading with the dynamic technique. Overlying veins could be removed on a workstation in all high-resolution examinations.

    CONCLUSION: The high-resolution carotid CE-MRA technique proposed herein seems to improve the diagnostic accuracy, at least for differentiation between high-grade stenoses and occlusions.

  • 86.
    Wikström, Johan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Ronne-Engström, E.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurokirurgi.
    Gal, Gyula
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Enblad, P.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurokirurgi.
    Tovi, Metin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för onkologi, radiologi och klinisk immunologi, Enheten för radiologi.
    Three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) and contrast-enhanced MRA of intracranial aneurysms treated with platinum coils2008Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 49, nr 2, s. 190-6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Contrast-enhanced magnetic resonance angiography (CE-MRA) is less prone to flow-related signal intensity loss than three-dimensional time-of-flight (3D TOF) MRA and may therefore be more sensitive for detection of residual patency in platinum coil-treated intracranial aneurysms. Purpose: To compare MRA and CE-MRA in the follow-up of intracranial aneurysms treated with platinum coils. MATERIAL AND METHODS: CE-MRA and 3D TOF MRA (pre- and postcontrast injection) of the intracranial vasculature was performed at 1.5T in 38 patients (47 aneurysms) referred for DSA in the follow-up of coiled intracranial aneurysms. RESULTS: DSA showed aneurysm patency in 22/47 investigations. Patent aneurysm components were observed with CE-MRA in 18/22 cases, and with 3D TOF MRA in 21/22 cases. There was no significant difference in patent aneurysm component size between CE-MRA and 3D TOF MRA. In addition, CE-MRA showed six, 3D TOF MRA before contrast injection showed seven, and 3D TOF MRA after contrast injection showed eight cases with patent aneurysm components not observed on DSA. CONCLUSION: 3D TOF MRA was highly sensitive for detection of patent aneurysm components, and at least as sensitive as CE-MRA. Residual aneurysm patency seems to be better visualized with MRA than with DSA in some cases.

  • 87.
    Zachrisson, Karin
    et al.
    Sahlgrens Univ Hosp, Dept Radiol, Grona Straket 2, SE-41345 Gothenburg, Sweden..
    Herlitz, Hans
    Sahlgrens Univ Hosp, Dept Mol & Clin Med, Nephrol, Gothenburg, Sweden..
    Lönn, Lars
    Univ Copenhagen, Rigshosp, Dept Radiol, Copenhagen, Denmark.;Univ Copenhagen, Rigshosp, Dept Vasc Surg, Copenhagen, Denmark..
    Falkenberg, Mårten
    Sahlgrens Univ Hosp, Dept Radiol, Grona Straket 2, SE-41345 Gothenburg, Sweden..
    Eklöf, Hampus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Duplex ultrasound for identifying renal artery stenosis: direct criteria re-evaluated2017Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, nr 2, s. 176-182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Renal artery duplex ultrasound (RADUS) is an established method for diagnosis of renal artery stenosis (RAS), but there is no consensus regarding optimal RADUS criteria. Purpose: To define optimal cutoff values for RADUS parameters when screening for RAS using intra-arterial transstenotic pressure gradient measurement (PGM) as reference. Material and Methods: The renal arteries of 58 consecutive patients evaluated for renovascular hypertension were examined by RADUS and PGM. Conclusive measurements with both methods were obtained in 76 arteries. Hemodynamically significant RAS was defined as PGM >= 15 mmHg and was found in 43 of the 76 arteries. RADUS parameters included renal artery peak systolic velocity (PSV) and the renal-aortic ratio (RAR) of flow velocities. Receiver operating characteristic curves (ROCs) and Youden's index were used to calculate optimal RADUS criteria for RAS. Results: When traditional RADUS criteria for RAS were used, with a combination of PSV >= 180 cm/s and RAR >= 3.5, the sensitivity was 62% and the specificity was 91%. When RADUS criteria were optimized for sensitivity, then RAR >= 2.6 alone resulted in a sensitivity of 89% and a specificity of 69%. Conclusion: The RAR >= 2.6 is a more sensitive criterion than traditional RADUS criteria when screening patients with clinical suspicion of RAS.

  • 88.
    Åström, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Abdsaleh, Shahin
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Brenning, G C
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Medicin.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    MR imaging of primary, secondary, and mixed forms of lymphedema2001Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 42, nr 4, s. 409-416Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To describe the pathological features and assess the diagnostic information of different MR sequences in patients with primary, secondary, and mixed (phlebo-, lipophlebo-, or lipolymphedema) forms of lymphedema of the lower leg.

    MATERIAL AND METHODS:

    In 26 patients with clinical diagnoses of primary (n=10), pure secondary (n=4), mixed (n=9) and combined secondary and mixed forms of lymphedema (n=3), MR imaging was performed with coronal and axial T1 SE, T2 TSE, fat-suppressed (SPIR) T2 sequences and axial T1 SE after i.v. injection of Gd-DTPA.

    RESULTS:

    In 24 patients there was a honeycomb pattern in the subcutis with a signal intensity corresponding to fluid (n=11), fibrosis (n=3), or both (n=10). Five patients with primary lymphedema showed subfascial fluid accumulation. Dermal edema was noted in 23 patients. Fat or edema components in the muscles were mostly seen in patients with phlebolymphedema. The honeycomb pattern was best seen on coronal T1 images, and fluid accumulations on axial SPIR-T2 images. Fibrosis was only assessible from the T2 TSE sequence. Gd-DTPA did not improve the diagnostic information.

    CONCLUSION:

    For evaluation of lymphedema and its mixed forms, an axial T2-weighted SPIR sequence in conjunction with a coronal T1 SE sequence are sufficient.

  • 89.
    Åström, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Sundström, J C
    Lindgren, P G
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för radiologi.
    Automatic biopsy instruments used through a coaxial bone biopsy system with an eccentric drill tip1995Ingår i: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 36, nr 3, s. 237-242Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Twenty-eight consecutive CT (n = 23) or ultrasonographically (n = 5) guided biopsy procedures were performed on musculoskeletal lytic lesions covered (n = 13) or not covered (n = 15) with intact bone. Specimens were obtained by means of Biopty techniques (n = 27), i.e. Biopty and Monopty instruments, through different cannulas with normal or shortened needle-throws. Four out of 5 bone penetrations were successful with an Ostycut needle, and all 8 bone penetrations by a coaxial bone biopsy system with an eccentric drill. The eccentric drill makes a hole in the cortical bone larger than the diameter of the outer cannula of this system, making it easy to anchor the cannula and then coaxially insert a Biopty-Gun needle for example. The overall histopathological diagnostic accuracy of the Biopty techniques was 25/27 (92.6%).

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