TY - JOUR AU - Machann, J. C1 - 72155 C2 - 56413 CY - 111 River St, Hoboken 07030-5774, Nj Usa TI - Editorial for "MR elastography for classification of focal liver lesions using viscoelastic parameters: A pilot study based on intrinsic and extrinsic activations". JO - J. Magn. Reson. Imaging PB - Wiley PY - 2024 SN - 1053-1807 ER - TY - JOUR AB - Background: Quantification of pancreatic fat (PF) and intrahepatic lipids (IHL) is of increasing interest in subjects at risk for metabolic diseases. There is limited data available on short- and medium-term variability of PF/IHL and on their dependence on nutritional status. Purpose: To assess short-term intraday variations of PF/IHL after a high-fat meal as well as medium-term changes after 5 days of high-caloric diet. Study Type: Prospective cohort study. Subjects: A total of 12 subjects (six males) for intraday variations study, 15 male subjects for medium-term high-caloric diet study and 11 age- and body mass index (BMI)-matched controls. Field Strength/Sequence: A 3 T; chemical-shift encoded multiecho gradient echo sequence. Assessment: For the intraday study, subjects were scanned after overnight fasting and after a high fat meal on the same day. For the medium-term study, 26 subjects were scanned after overnight fasting with 15/11 rescanned after 5 days of high-calorie diet/isocaloric diet. Proton density fat fraction (PDFF) maps were generated inline on the scanner. Regions of interest were manually drawn in head, body, and tail of pancreas and in the liver by a medical physicist and a doctoral student (26/4 years of experience). PF was calculated as the average of the head, body, and tail measurements. Statistical Tests: Repeated measurements ANOVA for assessing changes in PF/IHL, linear correlation analyses for assessing relationships of PF/IHL with BMI. Significance level P < 0.05 for all. Results: Nonsignificant changes in PF (2.6 ± 1.0 vs. 2.7 ± 0.9% after high-fat meal, 1.4 ± 0.8 vs. 1.5 ± 0.6% [high-caloric diet] and 1.5 ± 0.8 vs. 1.8 ± 1.0% [isocaloric control group]), nonsignificant changes in IHL after high-fat meal (2.6 ± 1.3 vs. 2.5 ± 0.9%) and in the control group (1.1 ± 0.6 vs. 1.2 ± 1.1%), significantly increased IHL after high-caloric diet (1.7 ± 2.2% vs. 2.7 ± 3.6%). Nonsignificant changes in PF (2.6 ± 1.0 vs. 2.7 ± 0.9% after high-fat meal, 1.4 ± 0.8 vs. 1.5 ± 0.6% [high-caloric diet] and 1.5 ± 0.8 vs. 1.8 ± 1.0% [isocaloric control group]), nonsignificant changes in IHL after high-fat meal (2.6 ± 1.3 vs. 2.5 ± 0.9%) and in the control group (1.1 ± 0.6 vs. 1.2 ± 1.1%), significantly increased IHL after 5-days of high-caloric diet (1.7 ± 2.2% vs. 2.7 ± 3.6%). Data Conclusion: Time of day and nutritional status have no significant influence on PF/IHL and are therefore not likely to be major confounders in epidemiologic or clinical studies. Evidence Level: 2. Technical Efficacy: Stage 1. AU - Machann, J. AU - Hasenbalg, M.* AU - Dienes, J.* AU - Wagner, R. AU - Sandforth, A. AU - Fritz, V.* AU - Birkenfeld, A.L. AU - Nikolaou, K.* AU - Kullmann, S. AU - Schick, F.* AU - Heni, M. C1 - 64204 C2 - 52107 CY - 111 River St, Hoboken 07030-5774, Nj Usa TI - Short-term variability of proton density fat fraction in pancreas and liver assessed by multiecho chemical-shift encoding-based MRI at 3 T. JO - J. Magn. Reson. Imaging VL - 56 IS - 4 PB - Wiley PY - 2022 SN - 1053-1807 ER - TY - JOUR AU - Machann, J. C1 - 62443 C2 - 50740 CY - 111 River St, Hoboken 07030-5774, Nj Usa SP - 541-542 TI - Editorial for "Concentration of gallbladder phosphatidylcholine in cholangiopathies: A 31 P MR spectroscopy pilot study". JO - J. Magn. Reson. Imaging VL - 55 IS - 2 PB - Wiley PY - 2021 SN - 1053-1807 ER - TY - JOUR AB - PURPOSE: To evaluate the volume and changes of human brown adipose tissue (BAT) in vivo following exposure to cold using magnetic resonance imaging (MRI). MATERIALS AND METHODS: The clavicular region of 10 healthy volunteers was examined with a 3T MRI system. One volunteer participated twice. A cooling vest that was circulated with temperature-controlled water was used to expose each volunteer to a cold environment. Three different water temperature phases were employed: baseline (23°C, 20 min), cooling (12°C, 90 min), and a final warming phase (37°C, 30 min). Temperatures of the water in the circuit, of the body, and at the back skin of the volunteers were monitored with fiberoptic temperature probes. Applying the 2-point DIXON pulse sequence every 5 minutes, fat fraction (FF) maps were determined and evaluated over time to distinguish between brown and white adipose tissue. RESULTS: Temperature measurements showed a decrease of 3.8 ± 1.0°C of the back skin temperature, while the body temperature stayed constant at 37.2 ± 0.9°C. Focusing on the two interscapular BAT depots, a mean FF decrease of -2.9 ± 2.0%/h (P < 0.001) was detected during cold stimulation in a mean absolute volume of 1.31 ± 1.43 ml. Also, a correlation of FF decrease to back skin temperature decrease was observed in all volunteers (correlation coefficients: |r| = [0.51; 0.99]). CONCLUSION: We found that FF decreases in BAT begin immediately with mild cooling of the body and continue during long-time cooling. AU - Stahl, V.* AU - Maier, F.* AU - Freitag, M.T.* AU - Floca, R.O.* AU - Berger, M.C.* AU - Umathum, R.* AU - Berriel Diaz, M. AU - Herzig, S. AU - Weber, M.A.* AU - Dimitrakopoulou-Strauss, A.* AU - Rink, K.* AU - Bachert, P.* AU - Ladd, M.E.* AU - Nagel, A.M.* C1 - 49093 C2 - 41643 CY - Hoboken SP - 369-380 TI - In vivo assessment of cold stimulation effects on the fat fraction of brown adipose tissue using DIXON MRI. JO - J. Magn. Reson. Imaging VL - 45 IS - 2 PB - Wiley-blackwell PY - 2017 SN - 1053-1807 ER - TY - JOUR AB - Purpose: To investigate the inhomogeneity of radiofrequency fields at higher field strengths that can interfere with established volumetric methods, in particular for the determination of visceral (VAT) and subcutaneous adipose tissue (SCAT). A versatile, interactive sparse sampling (VISS) method is proposed to determine VAT, SCAT, and also total body volume (TBV). Materials and Methods: VISS is based on a separation of major components by contour lines, followed by a sparse sampling algorithm, and eventually a quick manual correction. T1-weighted whole body scans of 24 subjects were evaluated (12 at 1.5T, 12 at 3.0T). Results: (a) Coefficients of variance (CV) and intra class correlation coefficients (ICC) determined within 3 raters (24 subjects) showed high consistency for SCAT (CV 2.2%, ICC 0.993) and VAT (CV 4.9%, ICC 0.987), (b) comparison with an established volumetric method revealed good agreement (Bland-Altman, VAT -0.68L to 1.07L, SCAT -2.18L to 8.39L), and (c) comparison of weights calculated from TBV with values measured on a scale resulted in an even better accuracy for VISS (Bland-Altman -1.98 kg to 4.09 kg) than for the reference method (-5.60 kg to 1.60 kg). Conclusion: VISS is reproducible in particular within the same rater, accurate as compared with established methods, and robust against low contrast and inhomogeneity artifacts. AU - Bühler, T.* AU - Ramseier, N.* AU - Machann, J. AU - Schwenzer, N.F.* AU - Boesch, C.* C1 - 10825 C2 - 30460 SP - 951-960 TI - Magnetic resonance imaging based determination of body compartments with the Versatile, Interactive Sparse Sampling (VISS) method. JO - J. Magn. Reson. Imaging VL - 36 IS - 4 PB - Wiley-Blackwell PY - 2012 SN - 1053-1807 ER - TY - JOUR AB - PURPOSE: To evaluate phase-sensitive inversion-recovery (PSIR) imaging at 1.5 T in a mouse model of permanent coronary artery ligation as a potentially rapid and robust alternative for the accurate assessment of myocardial infarction (MI) by cardiac magnetic resonance imaging (MRI). MATERIALS AND METHODS: PSIR late gadolinium enhancement (LGE) imaging was compared to conventional 2D segmented inversion-recovery imaging for the assessment of murine MI. RESULTS: PSIR images provided comparable contrast and kinetics of intravenously injected gadopentetate dimeglumine (Gd-DTPA). At the mid-ventricular level there was good agreement between conventional IR and PSIR for infarct size assessment. After intravenous injection a limited time window of ∼6 minutes is available for delayed enhancement imaging in mice. Whole-heart infarct imaging with 1 mm thick slices was only possible in this restricted time frame when the PSIR method is applied, avoiding the need for repetitively adapting the correct inversion time. Infarct size determined by PSIR MRI demonstrated good agreement with postmortem histology. Infarct size determined by PSIR LGE MRI inversely correlates with left-ventricular function on day 7 after MI. CONCLUSION: The PSIR technique provides stable and consistent contrast between hyperenhanced and remote myocardium independent of the selected inversion time (TI) and proved to be a robust, fast, and accurate tool for the assessment of MI in mice. AU - Wildgruber, M.* AU - Settles, M.* AU - Kosanke, K.* AU - Bielicki, I.* AU - Ntziachristos, V. AU - Rummeny, E.J.* AU - Botnar, R.M.* AU - Huber, A.M.* C1 - 10587 C2 - 30297 SP - 1372-1382 TI - Evaluation of phase-sensitive versus magnitude reconstructed inversion recovery imaging for the assessment of myocardial infarction in mice with a clinical magnetic resonance scanner. JO - J. Magn. Reson. Imaging VL - 36 IS - 6 PB - Wiley-Blackwell PY - 2012 SN - 1053-1807 ER - TY - JOUR AU - Eckstein, F.* AU - Stammberger, T. AU - Priebsch, J.* AU - Englmeier, K.-H. AU - Reiser, M.* C1 - 21296 C2 - 19411 SP - 161-167 TI - Effect of Gradient and Section Orientation on Quantitative Analyse of Knee Joint Cartilage. JO - J. Magn. Reson. Imaging VL - 11 PY - 2000 SN - 1053-1807 ER - TY - JOUR AU - Eckstein, F.* AU - Stammberger, T. AU - Priebsch, J.* AU - Englmeier, K.-H. AU - Reiser, M.* C1 - 21515 C2 - 19636 SP - 161-167 TI - Effect of Gradient and Section Orientation on quantitative Analysis of Knee Joint Cartilage. JO - J. Magn. Reson. Imaging VL - 11 PY - 2000 SN - 1053-1807 ER -