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  • 1.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Ortiz-Nieto, Francisco
    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.
    Weis, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Human brain MR spectroscopy thermometry using metabolite aqueous-solution calibrations2010In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 31, no 4, p. 807-814Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To estimate absolute brain temperature using proton MR spectroscopy ((1)H-MRS) and mean brain-body temperature difference of healthy human volunteers. MATERIALS AND METHODS: Chemical shift difference between temperature-dependent water spectral line position and temperature-stable metabolite spectral reference was used for the estimations of absolute brain temperature. Temperature calibrations constants were obtained from the spectra of the N-acetyl aspartate (NAA line at approximately 2.0 ppm), glycero-phosphocholine (GPC line at approximately 3.2 ppm), and creatine (Cr line at approximately 3.0 ppm) aqueous solutions with pH values within physiologically pertinent ranges. Single-voxel PRESS sequence (TR/TE 2000/80 ms) was used for this purpose. Brain temperature was determined by averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences. RESULTS: The mean brain temperature of 18 healthy volunteers was 38.1 +/- 0.4 degrees C and mean brain-body (rectal) temperature difference was 1.3 +/- 0.4 degrees C. CONCLUSION: Improved accuracy of the temperature constants and averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences increased the reliability of the brain temperature estimations.

  • 2.
    Hellström, Jussi
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Romanos Zapata, Romina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Libard, Sylwia
    Alafuzoff, Irina
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Clinical value of MR spectroscopy: How often does MRS yield more information than MRI?2015In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 57, no Suppl1, p. 143-144Article in journal (Refereed)
  • 3.
    Hellström, Jussi
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Romanos Zapata, Romina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Libard, Sylwia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology. Department of Pathology, Uppsala University Hospital, Uppsala, Sweden.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Evaluation of the INTERPRET decision-support system: can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?2019In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 61, no 1, p. 43-53Article in journal (Refereed)
    Abstract [en]

    Purpose: We evaluated in a clinical setting the INTERPRET decision-support system (DSS), a software generated to aid in MRS analysis to achieve a specific diagnosis for brain lesions.

    Methods: The material consisted of 100 examinations of focal intracranial lesions with confirmed diagnoses. MRS was obtained at 1.5 T using TE 20–30 ms. Data were processed with the LCModel for conventional analysis. The INTERPRET DSS 3.1. was used to obtain specific diagnoses. MRI and MRS were reviewed by one interpreter. DSS analysis was made by another interpreter, in 80 cases by two interpreters. The diagnoses were compared with the definitive diagnoses. For comparisons between DSS, conventional MRS analysis, and MRI, the diagnoses were categorised: high-grade tumour, low-grade tumour, non-neoplastic lesion.

    Results: Interobserver agreement in choosing the diagnosis from the INTERPRET database was 75%. The diagnosis was correct in 38/100 cases, incorrect in 57 cases. No good match was found in 5/100 cases. The diagnostic category was correct with DSS/conventional MRS/MRI in 67/58/52 cases, indeterminate in 5/8/20 cases, incorrect in 28/34/28 cases. Results with DSS were not significantly better than with conventional MRS analysis. All definitive diagnoses did not exist in the INTERPRET database. In the 61 adult patients with the diagnosis included in the database, DSS/conventional MRS/MRI yielded a correct diagnosis category in 48/32/29 cases (DSS vs conventional MRS: p = 0.002, DSS vs MRI: p = 0.0004).

    Conclusion: Use of the INTERPRET DSS did not improve MRS categorisation of the lesions in the unselected clinical cases. In adult patients with lesions existing in the INTERPRET database, DSS improved the results, which indicates the potential of this software with an extended database.

  • 4.
    Hellström, Jussi
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Romanos Zapata, Romina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Libard, Sylwia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology. Department of Pathology, Uppsala University Hospital, Uppsala, Sweden.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology. Department of Pathology, Uppsala University Hospital, Uppsala, Sweden.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    The value of magnetic resonance spectroscopy as a supplement to MRI of the brain in a clinical setting2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 11, article id e0207336Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: There are different opinions of the clinical value of MRS of the brain. In selected materials MRS has demonstrated good results for characterisation of both neoplastic and non-neoplastic lesions. The aim of this study was to evaluate the supplemental value of MR spectroscopy (MRS) in a clinical setting.

    MATERIAL AND METHODS: MRI and MRS were re-evaluated in 208 cases with a clinically indicated MRS (cases with uncertain or insufficient information on MRI) and a confirmed diagnosis. Both single voxel spectroscopy (SVS) and chemical shift imaging (CSI) were performed in 105 cases, only SVS or CSI in 54 and 49 cases, respectively. Diagnoses were grouped into categories: non-neoplastic disease, low-grade tumour, and high-grade tumour. The clinical value of MRS was considered very beneficial if it provided the correct category or location when MRI did not, beneficial if it ruled out suspected diseases or was more specific than MRI, inconsequential if it provided the same level of information, or misleading if it provided less or incorrect information.

    RESULTS: There were 70 non-neoplastic lesions, 43 low-grade tumours, and 95 high-grade tumours. For MRI, the category was correct in 130 cases (62%), indeterminate in 39 cases (19%), and incorrect in 39 cases (19%). Supplemented with MRS, 134 cases (64%) were correct, 23 cases (11%) indeterminate, and 51 (25%) incorrect. Additional information from MRS was beneficial or very beneficial in 31 cases (15%) and misleading in 36 cases (17%).

    CONCLUSION: In most cases MRS did not add to the diagnostic value of MRI. In selected cases, MRS may be a valuable supplement to MRI.

  • 5.
    Hellström, Jussi
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Romanos Zapata, Romina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Libard, Sylwia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Evaluation of INTERPRET Decision Support System (DSS) in clinical MRS of intracranial lesions and comparison to conventional MRS analysis and MRI.2015In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 57, no Suppl1, p. 67-68Article in journal (Refereed)
  • 6.
    Kullberg, Joel
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Reproducibility of hepatic triglyceride content assessment in normals using localized magnetic resonance spectroscopy2009In: Diabetes, obesity and metabolism, ISSN 1462-8902, E-ISSN 1463-1326, Vol. 11, no 5, p. 516-518Article in journal (Refereed)
    Abstract [en]

    AIM: To investigate the reproducibility of measurements of hepatic triglyceride content (HTGC) in subjects with normal HTGC using localized (1)H-magnetic resonance spectroscopy ((1)H-MRS) and a clinical 1.5T scanner. METHODS: The (1)H-MRS acquisition was performed with a common protocol using the whole-body coil and no respiratory triggering. An upper limit of normal HTGC of 5.56% was used. Duplicate measurements, including subject repositioning, were acquired from 23 subjects, 19 of whom had a normal HTGC. RESULTS: The mean coefficient of variation (CV) from the duplicate measurements was 14.8% (20.5% before exclusion of a subject who was considered to be an outlier). Mean CVs of subgroups below and above the 1% HTGC limit were 19.8 and 7.0 respectively. CONCLUSIONS: The mean CV calculated in subjects with HTGC in the normal range was found to be higher than CVs of wide range HTGC groups reported in the literature. It is concluded that the reproducibility of HTGC measurements using (1)H-MRS depends on the HTGC range. These findings are of importance in reproducibility studies and in estimations of required study group sizes.

  • 7.
    Marchesi, Silvia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
    Larsson, A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Ahlgren, Kerstin M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Autoimmunity.
    Lattuada, M.
    Policlin Milano, Milan, Italy..
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Hedenstierna, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology.
    Enhanced Abdominal Inflammation In Acute Respiratory Failure - Is The Culprit Ventilator Associated Abdominal Edema Or Inadequate Perfusion?: A Magnetic Resonance Imaging Pilot Study2015In: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 191Article in journal (Other academic)
  • 8.
    Marchesi, Silvia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlgren, Kerstin M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
    Roneus, Agneta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Feinstein, Ricardo
    Statens Veterinärmedicinska Anstalt, Uppsala, Sweden.
    Lipcsey, Miklós
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
    Larsson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Hedenstierna, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Hedenstierna laboratory.
    Abdominal organ perfusion and inflammation in experimental sepsis: a magnetic resonance imaging study2019In: American Journal of Physiology - Gastrointestinal and Liver Physiology, ISSN 0193-1857, E-ISSN 1522-1547, Vol. 316, no 1, p. G187-G196Article in journal (Refereed)
    Abstract [en]

    Diffusion-weighted magnetic resonance imaging (DW-MRI) uses water as contrast and enables the study of perfusion in many organs simultaneously in situ. We used DW-MRI in a sepsis model, comparing abdominal organs perfusion with global hemodynamic measurements and inflammation. Sixteen anesthetized piglets were randomized into 3 groups: HighMAP (mean arterial pressure, MAP > 65 mmHg), LowMAP (MAP between 50 and 60 mmHg) and Healthy Controls (HC). Sepsis was obtained with endotoxin and the desired MAP maintained with noradrenaline. After 6 hours DW-MRI was performed. Acute inflammation was assessed with IL-6 and TNFα in abdominal organs, ascites, and blood and by histology of intestine (duodenum). Perfusion of abdominal organs was reduced in the LowMAP group compared to the HighMAP group and HC. Liver perfusion was still reduced by 25% in the HighMAP group compared with HC. Intestinal perfusion did not differ significantly between the study groups. Cytokines concentration were generally higher in the LowMAP group but did not correlate with global hemodynamics. However, cytokines correlated with regional perfusion and, for liver and intestine, also with intra-abdominal pressure. Histopathology of intestine worsened with decreasing perfusion. In conclusion, although a low MAP (≤60 mmHg) indicated impeded abdominal perfusion in experimental sepsis, it did not predict inflammation, nor did other global measures of circulation. Decreased abdominal perfusion predicted partially inflammation but intestine, occupying most of the abdomen, and liver, were also affected by intra-abdominal pressure.

  • 9.
    Ortiz-Nieto, Francisco
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Johansson, Lars
    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.
    Weis, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Quantification of lipids in human lower limbs using yellow bone marrow as the internal reference: gender-related effects2010In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 28, no 5, p. 676-682Article in journal (Refereed)
    Abstract [en]

    The main purpose of this study was to determine and compare extra- and intramyocellular (IMCL) lipids content in the calf and thigh muscles of normal male and female volunteers using high-spatial-resolution magnetic resonance spectroscopic imaging (MRSI). The study groups consisted of 10 females and 10 males. The subjects were healthy and normal-weight. Fat (yellow bone marrow) was used as the internal concentration reference. Total fat and IMCL content were computed for all muscles in the slice and for three muscle compartments in the thigh, whereas three muscles and three muscle compartments were evaluated in the calf. To avoid the confounding effects of physical activity and diet, measurements were performed in the same session. A common feature for both genders was that thigh muscles had approximately 2.5 times greater total fat content as compared to muscles of the calf. The mean IMCL level was, however, more than 3 times higher in the calf muscles compared with the thigh. No significant differences in lipid concentrations of correspondent regions of interest were found between genders. The high-spatial-resolution MRSI technique enables a more detailed study of muscle lipid distribution and can therefore improve understanding of muscle lipid metabolism in healthy volunteers and in studies of patients with metabolic disorders.

  • 10.
    Rhodin, Annika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    von Ehren, Michaela
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Skottheim, B
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Grönbladh, Alfhild
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Gordh, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Nyberg, Fred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Recombinant human growth hormone improves cognitive capacity in a pain patient exposed to chronic opioids2014In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 58, no 6, p. 759-765Article in journal (Refereed)
    Abstract [en]

    During recent decades, the increasing use of opioids for chronic non-cancer pain has raised concerns regarding tolerance, addiction, and importantly cognitive dysfunction. Current research suggests that the somatotrophic axis could play an important role in cognitive function. Administration of growth hormone (GH) to GH-deficient humans and experimental animals has been shown to result in significant improvements in cognitive capacity. In this report, a patient with cognitive disabilities resulting from chronic treatment with opioids for neuropathic pain received recombinant human growth hormone (rhGH) replacement therapy. A 61-year-old man presented with severe cognitive dysfunction after long-term methadone treatment for intercostal neuralgia and was diagnosed with GH insufficiency by GH releasing hormone-arginine testing. The effect of rhGH replacement therapy on his cognitive capacity and quality of life was investigated. The hippocampal volume was measured using magnetic resonance imaging, and the ratios of the major metabolites were calculated using proton magnetic resonance spectroscopy. Cognitive testing revealed significant improvements in visuospatial cognitive function after rhGH. The hippocampal volume remained unchanged. In the right hippocampus, the N-acetylaspartate/creatine ratio (reflecting nerve cell function) was initially low but increased significantly during rhGH treatment, as did subjective cognitive, physical and emotional functioning. This case report indicates that rhGH replacement therapy could improve cognitive behaviour and well-being, as well as hippocampal metabolism and functioning in opioid-treated patients with chronic pain. The idea that GH could affect brain function and repair disabilities induced by long-term exposure to opioid analgesia is supported.

  • 11.
    Romanos Zapata, Romina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ortiz-Nieto, Fransisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Differential diagnosis of brain lesions using MRI, proton MR spectroscopy (MRS) and INTERPRET Decision Making System (DSS): A comparative study2013In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 55, no Suppl1, p. S76-Article in journal (Refereed)
  • 12.
    Rönn, Monika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lind, Monica P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Karlsson, Helen
    Cvek, Katarina
    Berglund, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Malmberg, Filip
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction.
    Örberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Lind, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cardiovascular epidemiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Quantification of total and visceral adipose tissue in fructose-fed rats using water-fat separated single echo MRI2013In: Obesity, ISSN 1930-7381, E-ISSN 1930-739X, Vol. 21, no 9, p. E388-E395Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of this study was to setup a rodent model for modest weight gain and an MRI-based quantification of body composition on a clinical 1.5 T MRI system for studies of obesity and environmental factors and their possible association. Design and Methods: Twenty-four 4-week-old female Fischer rats were divided into two groups: one exposed group (n=12) and one control group (n 12). The exposed group was given drinking water containing fructose (5% for 7 weeks, then 20% for 3 weeks). The control group was given tap water. Before sacrifice, whole body MRI was performed to determine volumes of total and visceral adipose tissue and lean tissue. MRI was performed using a clinical 1.5 T system and a chemical shift based technique for separation of water and fat signal from a rapid single echo acquisition. Fat signal fraction was used to separate adipose and lean tissue. Visceral adipose tissue volume was quantified using semiautomated segmentation. After sacrifice, a perirenal fat pad and the liver were dissected and weighed. Plasma proteins were analyzed by Western blot. Results: The weight gain was 5.2% greater in rats exposed to fructose than in controls (P=0.042). Total and visceral adipose tissue volumes were 5.2 cm(3) (P=0.017) and 3.1 cm(3) (P=0.019) greater, respectively, while lean tissue volumes did not differ. The level of triglycerides and apolipoprotein A-I was higher (P=0.034, P=0.005, respectively) in fructose-exposed rats.

  • 13.
    Sohlberg, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Mulic-Lutvica, Ajlana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Lindgren, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Ortiz-Nieto, Fransisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Wikström, Anna-Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Placental perfusion in normal pregnancy and early and late preeclampsia: A magnetic resonance imaging study.2014In: Placenta, ISSN 0143-4004, E-ISSN 1532-3102, Vol. 35, no 3, p. 202-206Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Our primary aim was to investigate if women with early or late preeclampsia have different placental perfusion compared with normal pregnancies. A secondary aim was to investigate if placental perfusion changes with increasing gestational age in normal pregnancy.

    METHODS: The study population included thirteen women with preeclampsia (five with early and eight with late preeclampsia) and nineteen women with normal pregnancy (ten with early and nine with late pregnancy). Early was defined as <34 weeks and late as ≥34 weeks gestation. All women underwent a magnetic resonance imaging (MRI) examination including a diffusion weighted sequence at 1.5 T. The perfusion fraction was calculated.

    RESULTS: Women with early preeclampsia had a smaller placental perfusion fraction (p = 0.001) and women with late preeclampsia had a larger placental perfusion fraction (p = 0.011), compared to women with normal pregnancies at the corresponding gestational age. The placental perfusion fraction decreased with increasing gestational age in normal pregnancies (p = 0.001).

    CONCLUSION: Both early and late preeclampsia differ in placental perfusion from normal pregnant women. Observed differences are however in the opposite direction, suggesting differences in pathophysiology. Placental perfusion decreases with increasing gestational age in normal pregnancy.

  • 14.
    Weis, Jan
    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.
    Hlavcak, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Häggman, Mikael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Bergman, Antonina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Two-dimensional spectroscopic imaging for pretreatment evaluation of prostate cancer: comparison with the step-section histology after radical prostatectomy2009In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 27, no 1, p. 87-93Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To minimize user and vendor dependence of the spectrum processing of prostate spectra, to measure the ratio of choline (Cho) plus creatine (Cr) to citrate (Cit) in the prostate tissue of normal volunteers and cancer patients, and to compare the results with pathologic findings after radical prostatectomy. MATERIALS AND METHODS: Four healthy volunteers and 13 patients with prostate cancer were measured. Measurements were performed using two-dimensional magnetic resonance spectroscopic imaging (MRSI) and endorectal coil. A standard vendor's spectrum processing approach has been modified. An original feature of this methodology was the combination of vendor-optimized and user-independent spectrum preprocessing in the scanner and user-independent quantitation in the environment of an MRUI software package. (Cho+Cr)/Cit ratio was used for the classification of prostate tissue. Results were compared with histopathology after radical prostatectomy. RESULTS: Eight of 13 cancer patients were classified as suspicious or very suspicious for cancer at spectroscopy, three were ambiguous for cancer and two patients were evaluated as false negative. A considerable overlap of metabolite ratios at various Gleason score was found. CONCLUSION: The proposed spectrum processing has the potential to improve the accuracy and user independency of the (Cho+Cr)/Cit quantitation. This study confirmed the previous results that a considerable overlap of (Cho+Cr)/Cit ratios exists at various Gleason score levels.

  • 15.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Bruvold, Morten
    Ortiz-Nieto, Francisco
    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.
    High-resolution echo-planar spectroscopic imaging of the human calf2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 1, p. e87533-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: This study exploits the speed benefits of echo-planar spectroscopic imaging (EPSI) to acquire lipid spectra of skeletal muscle. The main purpose was to develop a high-resolution EPSI technique for clinical MR scanner, to visualise the bulk magnetic susceptibility (BMS) shifts of extra-myocellular lipid (EMCL) spectral lines, and to investigate the feasibility of this method for the assessment of intra-myocellular (IMCL) lipids.

    METHODS: The study group consisted of six healthy volunteers. A two dimensional EPSI sequence with point-resolved spectroscopy (PRESS) spatial localization was implemented on a 3T clinical MR scanner. Measurements were performed by means of 64×64 spatial matrix and nominal voxel size 3×3×15 mm(3). The total net measurement time was 3 min 12 sec for non-water-suppressed (1 acquisition) and 12 min 48 sec for water-suppressed scans (4 acquisitions).

    RESULTS: Spectra of the human calf had a very good signal-to-noise ratio and linewidths sufficient to differentiate IMCL resonances from EMCL. The use of a large spatial matrix reduces inter-voxel signal contamination of the strong EMCL signals. Small voxels enabled visualisation of the methylene EMCL spectral line splitting and their BMS shifts up to 0.5 ppm relative to the correspondent IMCL line. The mean soleus muscle IMCL content of our six volunteers was 0.30±0.10 vol% (range 0.18-0.46) or 3.6±1.2 mmol/kg wet weight (range: 2.1-5.4).

    CONCLUSION: This study demonstrates that high-spatial resolution PRESS EPSI of the muscle lipids is feasible on standard clinical scanners.

  • 16.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Allers, Mats
    Lunderquist, Anders
    Ortiz-Nieto, Francisco
    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.
    Phase-difference and spectroscopic imaging for monitoring of human brain temperature during cooling2012In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 30, no 10, p. 1505-1511Article in journal (Refereed)
    Abstract [en]

    Decrease of the human brain temperature was induced by intranasal cooling. The main purpose of this study was to compare the two magnetic resonance methods for monitoring brain temperature changes during cooling: phase-difference and magnetic resonance spectroscopic imaging (MRSI) with high spatial resolution. Ten healthy volunteers were measured. Selective brain cooling was performed through nasal cavities using saline-cooled balloon catheters. MRSI was based on a radiofrequency spoiled gradient echo sequence. The spectral information was encoded by incrementing the echo time of the subsequent eight image records. Reconstructed voxel size was 1×1×5 mm3. Relative brain temperature was computed from the positions of water spectral lines. Phase maps were obtained from the first image record of the MRSI sequence. Mild hypothermia was achieved in 15–20 min. Mean brain temperature reduction varied in the interval <−3.0; − 0.6>°C and <−2.7; − 0.7>°C as measured by the MRSI and phase-difference methods, respectively. Very good correlation was found in all locations between the temperatures measured by both techniques except in the frontal lobe. Measurements in the transversal slices were more robust to the movement artifacts than those in the sagittal planes. Good agreement was found between the MRSI and phase-difference techniques.

  • 17.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ortiz-Nieto, Francisco
    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.
    Assessment of lipids in skeletal muscle by high-resolution spectroscopic imaging using fat as the internal standard: comparison with water referenced spectroscopy2008In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 59, no 6, p. 1259-1265Article in journal (Refereed)
    Abstract [en]

    The main purpose of the study was to compare proton (1H) single-voxel MR spectroscopy (MRS) with high-spatial-resolution spectroscopic imaging (MRSI) to determine the lipid content in human skeletal muscle. Unsuppressed water line was used as a concentration reference in the processing of single-voxel spectra. The spectrum from yellow bone marrow with a 100% fat content and probe with the vegetable oil served as internal and external reference for high-spatial-resolution MRSI, respectively. Very good correlation was found between lipid concentrations measured by water referenced single-voxel MRS and high-spatial-resolution MRSI with yellow bone marrow as the internal standard. Excellent correlation was found between total lipid concentrations estimated by high-spatial-resolution MRSI with vegetable oil as the external fat standard and yellow bone marrow as the internal reference. From comparison of single-voxel MRS and MRSI approaches, it follows that relaxation correction of the reference water and methylene fat line is inevitable in processing the standard single-voxel spectra. The high-resolution MRSI approach is recommended to avoid the problem of relaxation corrections and enables using vegetable oil as the external fat standard.

  • 18.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Johansson, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ortiz-Nieto, Francisco
    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.
    Assessment of lipids in skeletal muscle by LCModel and AMARES2009In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 30, no 5, p. 1124-1129Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To process single voxel spectra of the human skeletal muscle by using an advanced method for accurate, robust, and efficient spectral fitting (AMARES) and by linear combination of model spectra (LCModel). To determine absolute concentrations of extra- (EMCL) and intramyocellular lipids (IMCL). MATERIALS AND METHODS: Single-voxel proton magnetic resonance spectroscopy (PRESS) was used to obtain the spectra of the calf muscles. Unsuppressed water line was used as a concentration reference. A new prior knowledge for AMARES was proposed to estimate the concentrations of EMCL and IMCL. The prior knowledge was derived from the spectrum of vegetable oil. The results were compared with the values estimated by LCModel. Absolute concentrations of total lipid content in millimoles per kilogram wet weight were used for the comparisons. RESULTS: Absolute concentrations of total lipid content in skeletal muscle were estimated by AMARES and LCModel. Very good correlation of the total fat (EMCL + IMCL) and IMCL concentrations was achieved between both data processing approaches. CONCLUSION: Assessment the absolute concentrations of muscular lipids by AMARES and LCModel can be performed with comparable accuracy.

  • 19.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Jorulf, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Bergman, Antonina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Häggman, Michael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    MR spectroscopy of the human prostate using surface coil at 3 T: Metabolite ratios, age-dependent effects, and diagnostic possibilities2011In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 34, no 6, p. 1277-1284Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To measure prostate spectra of healthy volunteers using a surface coil, to demonstrate age-dependent effects, and to investigate diagnostic possibilities for prostate cancer detection.

    MATERIALS AND METHODS:

    Single-voxel and 2D magnetic resonance spectroscopic imaging (MRSI) spectra of 51 healthy volunteers with biopsy-proven prostate carcinoma of 20 patients for comparison were measured and processed using the LCModel. The mean normalized spectra and mean metabolite-to-citrate intensity ratios were computed.

    RESULTS:

    Metabolite-to-citrate ratios of healthy volunteers were lower in the older group (>51 years) than in the younger group (<45 years). The peripheral zone (PZ) revealed a lower metabolite-to-citrate intensity ratio than the central gland (CG). Age-related differences in metabolite-to-citrate ratio were insignificant in the voxels with predominantly CG tissue, whereas significant differences were found in the PZ. Sensitivity in detecting prostate cancer by single-voxel spectroscopy (SVS) and 2D MRSI was 75% and 80%, respectively.

    CONCLUSION:

    SVS and 2D MRSI of the prostate at 3 T, using a surface coil, are useful in situations when insertion of the endorectal coil into the rectum is difficult or impossible. Our findings of age-dependent effects may be of importance for the analysis of patient spectra.

  • 20.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ortiz-Nieto, Francisco
    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.
    MR Spectroscopy of the Prostate at 3T: Measurements of Relaxation Times and Quantification of Prostate Metabolites using Water as an Internal Reference2013In: Magnetic resonance in medical sciences, ISSN 1347-3182, Vol. 12, no 4, p. 289-296Article in journal (Refereed)
    Abstract [en]

    Purpose:

    We performed single-voxel magnetic resonance spectroscopy (MRS) of the human prostate at 3 tesla using a surface coil to measure prostate water, choline (Cho), creatine (Cr), and citrate (Cit) relaxation times T1, T2, and to estimate concentrations of Cho, Cr, and Cit in healthy volunteers.

    Methods:

    In nine of 17 healthy volunteers, we performed experiments to estimate relaxation time, and we used the spectra of the other eight to compute metabolite concentrations. Spectra were processed by LCModel and AMARES (advanced method for accurate, robust, and efficient spectral fitting) algorithms. T1 and T2 values were obtained by monoexponential fitting of the spectral intensities. Metabolite concentrations were estimated using prostate tissue water as an internal concentration reference.

    Results:

    Relaxation times are reported for prostate water (T1, 2163±166 ms; T2, 110±18 ms), Cho (T1, 987±71 ms; T2, 239±24 ms), Cr (T1, 1128±149 ms; T2, 188±20 ms), and Cit (T1, 476±70 ms; T2, 228±42 ms). Mean concentrations in healthy prostate were Cho, 2.6±0.3 mM, Cr, 5.8±1.3 mM, and Cit, 26.9±5.5 mM.

    Conclusion:

    We observed metabolite relaxation times and concentrations consistent with published values of healthy volunteers at 1.5 and 3T. T1 values increased and T2 slightly decreased with magnetic field strength. Our preliminary patient results indicate that water-referenced quantitative MRS of the human prostate is a promising tool for monitoring therapeutic effects and detecting tumor relapse, i.e., in situations when Cit intensity is small or undetectable.

  • 21.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ring, Patrik
    Olofsson, Tommie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Short echo time MR spectroscopy of brain tumors: grading of cerebral gliomas by correlation analysis of normalized spectral amplitudes2010In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 31, no 1, p. 39-45Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To process single voxel spectra of low- and high-grade gliomas. To propose correlation analysis of the scatter plots of normalized spectral amplitudes as a pattern recognition tool for the classification (grading) of brain tumors. To propose a spectrum processing approach that improves the differentiation of proton spectra with dominating macromolecule and lipid peaks. MATERIALS AND METHODS: LCModel was used to process spectra. Mean metabolite concentrations and mean normalized spectra were obtained for normal white matter and for gliomas. The mean spectra of macromolecules and lipids (ML) in the range 1.4-0.9 ppm, and mean difference spectra (DS) without ML and lactate were computed. Correlation analysis of the scatter plot of the patient and mean normalized spectral amplitudes and dispersion of the scatter plot points were used for classification and grading of tumors. RESULTS: It was found advantageous to perform the classifications using DS spectra. The shape of ML spectrum and concentration of tCr seem to be a good markers for glioma grade. CONCLUSION: Combining a qualitative comparison of the patient and mean DS spectra of the tumors using correlation analysis of normalized spectra amplitudes with a quantitative comparison of metabolite concentrations is a powerful tool in studying brain lesions.

  • 22.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    von Below, Catrin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Tolf, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wassberg, Cecilia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Haggman, Michael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Ladjevardi, Sam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Quantification of metabolite concentrations in benign and malignant prostate tissues using 3D proton MR spectroscopic imaging2017In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 45, no 4, p. 1232-1240Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To estimate concentrations of choline (Cho), spermine (Spm), and citrate (Cit) in prostate tissue using 3D proton magnetic resonance spectroscopic imaging (MRSI) with water as an internal concentration reference as well as to assess the relationships between the measured metabolites and also between the metabolites and apparent diffusion coefficient (ADC).

    MATERIALS AND METHODS: Forty-six prostate cancer patients were scanned at 3T. Spectra were acquired with the point-resolved spectroscopy (PRESS) localization technique. Single-voxel spectra of four healthy volunteers were used to estimate T1 relaxation time of Spm. Spm, Cho concentrations, and ADC values of benign prostate tissues were correlated with Cit content.

    RESULTS: The T1 value, 708 ± 132 msec, was estimated for Spm. Mean concentrations in the benign peripheral zone (PZ) were Cho, 4.5 ± 1 mM, Spm, 13.0 ± 4.4 mM, Cit, 64.4 ± 16.1 mM. Corresponding values in the benign central gland (CG) were Cho, 3.6 ± 1 mM, Spm, 13.3 ± 4.5 mM, Cit, 34.3 ± 12.9 mM. Concentrations of Cit and Spm were positively correlated in the benign PZ zone (r = 0.730) and CG (r = 0.664). Positive correlation was found between Cit and Cho in the benign CG (r = 0.705). Whereas Cit and ADC were positively correlated in the benign PZ (r = 0.673), only low correlation was found in CG (r = 0.265).

    CONCLUSION: We have shown that it is possible to perform water-referenced quantitative 3D MRSI of the prostate at the cost of a relatively short prolongation of the acquisition time. The individual metabolite concentrations provide additional information compared to the previously used metabolite-to-citrate ratios.

1 - 22 of 22
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