TY  - JOUR
AB  - PURPOSE: Excess fat accumulation contributes significantly to metabolic dysfunction and diseases. This study aims to systematically compare the accuracy of commercially available Dixon techniques for quantification of fat fraction in liver, skeletal musculature, and vertebral bone marrow (BM) of healthy individuals, investigating biases and sex-specific influences. METHOD: 100 healthy White individuals (50 women) underwent abdominal MRI using two-point and multi-echo Dixon sequences. Fat fraction (FF), proton density fat fraction (PDFF) and T2* values were calculated for liver, paravertebral muscles (PVM) and vertebral BM (Th8-L5). Agreement and systematic deviations were assessed using linear correlation and Bland-Altman plots. RESULTS: High correlations between FF and PDFF were observed in liver (r = 0.98 for women; r = 0.96 for men), PVM (r = 0.92 for women; r = 0.93 for men) and BM (r = 0.97 for women; r = 0.95 for men). Relative deviations between FF and PDFF in liver (18.92 % for women; 13.32 % for men) and PVM (1.96 % for women; 11.62 % for men) were not significant. Relative deviations in BM were significant (38.13 % for women; 27.62 % for men). Bias correction using linear models reduced discrepancies. T2* times were significantly shorter in BM (8.72 ms for women; 7.26 ms for men) compared to PVM (13.45 ms for women; 13.62 ms for men) and liver (29.47 ms for women; 26.35 ms for men). CONCLUSION: While no significant differences were observed for liver and PVM, systematic errors in BM FF estimation using two-point Dixon imaging were observed. These discrepancies - mainly resulting from organ-specific T2* times - have to be considered when applying two-point Dixon approaches for assessment of fat content. As suitable correction tools, linear models could provide added value in large-scale epidemiological cohort studies. Sex-specific differences in T2* should be considered.
AU  - Haueise, T.
AU  - Schick, F.
AU  - Stefan, N.*
AU  - Machann, J.
C1  - 69952
C2  - 55335
TI  - Comparison of the accuracy of commercial two-point and multi-echo Dixon MRI for quantification of fat in liver, paravertebral muscles, and vertebral bone marrow.
JO  - Eur. J. Radiol.
VL  - 172
PY  - 2024
SN  - 0720-048X
ER  - 

TY  - JOUR
AB  - PURPOSE: To investigate the feasibility of liver fat quantification in contrast-enhanced dual source dual energy computed tomography (DECT) using multi-echo Dixon magnetic resonance imaging (MRI) as reference standard. METHOD: Patients who underwent MRI of the liver including a multi-echo Dixon sequence for estimation of proton density fat fraction in 2017 as well as contrast-enhanced DECT imaging of the abdomen were included in this retrospective, monocentric IRB approved study. Furthermore, patients with a hepatic fat amount >5% who were examined in 2018 with MRI and DECT were included. The final study group consisted of 81 patients with 90 pairs of examinations. Analysis of parameter maps was performed manually using congruent regions of interest which were placed in the liver parenchyma, in the erector spinae muscles, and psoas major muscles. RESULTS: Mean patient age was 61 ± 13 years. Median time between MRI and DECT was 48 days. MRI liver fat quantification resulted in a median of 3.8% (IQR: 2.2-8.2%) compared to 1.8% (IQR: 0-6.3%) in DECT (p < 0.001), with a Spearman correlation of 0.73. Bland-Altman analysis resulted in a systematic underestimation of liver fat in DECT, with a mean difference of -1.7%. Fat quantification in the erector spinae muscles (p = 0.257) and the psoas major muscles (p = 0.208) was not significantly different in DECT compared to MRI. CONCLUSIONS: Liver and muscular fat quantification in portal-venous phase DECT is feasible with good to excellent correlation compared to a multi-echo Dixon MRI sequence analysis. While there is an underestimation of the liver fat content in DECT, there are no significant differences between DECT and MRI fat quantification of the erector spinae and psoas major muscles.
AU  - Gassenmaier, S.*
AU  - Kähm, K.*
AU  - Walter, S.S.*
AU  - Machann, J.
AU  - Nikolaou, K.*
AU  - Bongers, M.N.*
C1  - 62565
C2  - 50947
CY  - Elsevier House, Brookvale Plaza, East Park Shannon, Co, Clare, 00000, Ireland
TI  - Quantification of liver and muscular fat using contrast-enhanced Dual Source Dual Energy Computed Tomography compared to an established multi-echo Dixon MRI sequence.
JO  - Eur. J. Radiol.
VL  - 142
PB  - Elsevier Ireland Ltd
PY  - 2021
SN  - 0720-048X
ER  - 

TY  - JOUR
AB  - PURPOSE: The evaluation process of potential living kidney donors focusses on renal anatomy and split renal function. This study aimed to evaluate a magnetic resonance imaging (MRI)-based approach for simultaneous evaluation of both and its impact on clinical decision making. METHOD: Over a 3-year period, 65 potential living kidney donors were consecutively enrolled. The MRI protocol was extended by MR-nephrography to measure split renal function. Standard DTPA-scintigraphy was used for functional comparison. RESULTS: Split renal function showed no systematic bias between the two methods (mean difference 0.3%, p = 0.08). Both methods would have yielded the same clinical decision for donor nephrectomy in 75% of the patients. In 25 % of the patients, one method indicated a relevant side difference while the other did not, and a different clinical decision could have been made based on split renal function alone. CONCLUSIONS: MRI proved eligible for comprehensive living kidney donor evaluation and non-inferior to scintigraphy for determining split renal function. In clinical decision making, these two methods would have resulted in the same side for donor nephrectomy in a large proportion of potential donors. Whether MRN will be implemented in clinical practice depends on transplant centre infrastructure and policy.
AU  - Krumm, P.*
AU  - Hupka, T.*
AU  - Haußmann, F.*
AU  - Dittmann, H.*
AU  - Mühlbacher, T.
AU  - Nadalin, S.*
AU  - Königsrainer, A.*
AU  - Nikolaou, K.*
AU  - Heyne, N.
AU  - Kramer, U.*
AU  - Guthoff, M.
C1  - 62636
C2  - 51013
CY  - Elsevier House, Brookvale Plaza, East Park Shannon, Co, Clare, 00000, Ireland
TI  - Contrast-enhanced MRI for simultaneous evaluation of renal morphology and split renal function in living kidney donor candidates.
JO  - Eur. J. Radiol.
VL  - 142
PB  - Elsevier Ireland Ltd
PY  - 2021
SN  - 0720-048X
ER  - 

TY  - JOUR
AB  - Objectives: Management of incidental findings (IF) remains controversial but highly relevant. Our aim was to assess the frequency, management and psychosocial consequences of IF reporting in a population-based cohort study undergoing whole-body MR imaging. Methods: The study was nested in a prospective cohort from a longitudinal, population-based cohort (KORA-FF4) in southern Germany. All MR obtained on 3 T MR scanner were reviewed by board-certified radiologists regarding clinically relevant IF. A baseline and follow-up questionnaires including PHQ-9 were completed prior to and 6-month after to the scan. Results: Of 400 participants (56.3 ± 9.2years, 58 % male) undergoing whole-body MR, IF were found in 22 % of participants (n = 89); most frequently located in the abdominal sequences. In the pre-scan survey, most participants stated as the motivation that they wanted to “contribute to a scientific purpose” (91 %), while “knowing whether I'm healthy” was the most frequent motivation reported 6 months post-scan (88 %). The desire for IF reporting increased over time (pre- vs. 6-months-post-scan), also for clinically less important IF (72 % vs. 84 %, p = 0.001). Regarding psychosocial impact, a small portion (3.4 %) reported that awaiting the IF report added “definitely” or “very probably” additional stress burden. Of participants with reported IF, 56.8 % classified the results as “very helpful”. In the post-scan survey moderate depression was observed in 3.3 % and severe depression in 1.2 %. This did not differ between participants with and without reported IF. Conclusion: In a cohort with whole-body MR imaging, the prevalence of IF was high. Participants considered reporting of IF highly important and added only minor psychological burden.
AU  - Schlett, C.L.*
AU  - Rospleszcz, S.
AU  - Korbmacher, D.*
AU  - Lorbeer, R.*
AU  - Auweter, S.*
AU  - Hetterich, H.*
AU  - Selder, S.*
AU  - Heier, M.
AU  - Linkohr, B.
AU  - Weckbach, S.*
AU  - Ertl-Wagner, B.*
AU  - Peters, A.
AU  - Bamberg, F.*
C1  - 60739
C2  - 49547
CY  - Elsevier House, Brookvale Plaza, East Park Shannon, Co, Clare, 00000, Ireland
TI  - Incidental findings in whole-body MR imaging of a population-based cohort study: Frequency, management and psychosocial consequences.
JO  - Eur. J. Radiol.
VL  - 134
PB  - Elsevier Ireland Ltd
PY  - 2021
SN  - 0720-048X
ER  - 

TY  - JOUR
AB  - OBJECTIVES: Intra- and intermyocellular lipid deposition and adipose tissue are part of glucose homeostasis and insulin resistance; however, their role in type 2 diabetes mellitus (T2DM) remains unclear. We assessed differences in the degree of abdominal myosteatosis among subjects with T2DM and prediabetes. MATERIALS AND METHODS: Asymptomatic subjects from the general population were classified as subjects with T2DM, prediabetes or healthy controls and underwent multi-echo Dixon magnetic resonance imaging (MRI) (TR 8.90 ms, six echo times, flip-angle 4°). Abdominal myosteatosis was quantified as proton-density fat-fraction (PDFF) by a standardized segmentation-algorithm. Cardiometabolic risk factors were prospectively obtained in a comprehensive health assessment and visceral and subcutaneous adipose tissue (VAT and SAT) were quantified semi-automatically. Uni- and multivariate quantile regression were used to examine associations. RESULTS: Among 349 included subjects (mean age: 56.0 ± 8.0years, 56.7% males), 45 were classified as subjects with T2DM and 84 with prediabetes (12.9% and 24.1%; respectively). Median PDFF was significantly higher in subjects with T2DM and prediabetes compared to healthy controls (13.1% (IQR10.5-16.6%); 11.1% (IQR8.9-15.0%) and 10.1% (IQR7.5-13.3%); respectively, p < 0.001). The observed differences were independent of age and gender (all p < 0.002) but attenuated after adjustment for BMI (β: -0.02, 95%CI: -1.49 to 1.44, p = 0.974; β: 0.47, 95%CI: -0.91 to 1.86, p = 0.506; prediabetes and T2DM, respectively). This effect was attributable to VAT, which remained independently associated with PDFF after full adjustment (β: 0.01, 95%CI: 0.01-0.02, p = 0.002). CONCLUSIONS: There are significant differences in the degree of abdominal myosteatosis between subjects with T2DM, prediabetes and healthy controls, that may be confounded by VAT. However, abdominal myosteatosis by MRI might serve as a cardiometabolic imaging-biomarker, specifically in the setting of impaired glucose metabolism.
AU  - Kiefer, L.S.*
AU  - Fabian, J.*
AU  - Rospleszcz, S.
AU  - Lorbeer, R.*
AU  - Machann, J.
AU  - Storz, C.*
AU  - Kraus, M.S.*
AU  - Schlett, C.L.*
AU  - Roemer, F.*
AU  - Wintermeyer, E.*
AU  - Rathmann, W.*
AU  - Nikolaou, K.*
AU  - Peters, A.
AU  - Bamberg, F.*
C1  - 53866
C2  - 45004
SP  - 261-268
TI  - Assessment of the degree of abdominal myosteatosis by magnetic resonance imaging in subjects with diabetes, prediabetes and healthy controls from the general population.
JO  - Eur. J. Radiol.
VL  - 105
PY  - 2018
SN  - 0720-048X
ER  - 

TY  - JOUR
AB  - OBJECTIVES: To evaluate the feasibility and incremental diagnostic value of xenon-enhanced dual-energy CT in mechanically ventilated intensive care patients with worsening respiratory function. METHODS: The study was performed in 13 mechanically ventilated patients with severe pulmonary conditions (acute respiratory distress syndrome (ARDS), n=5; status post lung transplantation, n=5; other, n=3) and declining respiratory function. CT scans were performed using a dual-source CT scanner at an expiratory xenon concentration of 30%. Both ventilation images (Xe-DECT) and standard CT images were reconstructed from a single CT scan. Findings were recorded for Xe-DECT and standard CT images separately. Ventilation defects on xenon images were matched to morphological findings on standard CT images and incremental diagnostic information of xenon ventilation images was recorded if present. RESULTS: Mean xenon consumption was 2.95l per patient. No adverse events occurred under xenon inhalation. In the visual CT analysis, the Xe-DECT ventilation defects matched with pathologic changes in lung parenchyma seen in the standard CT images in all patients. Xe-DECT provided additional diagnostic findings in 4/13 patients. These included preserved ventilation despite early pneumonia (n=1), more confident discrimination between a large bulla and pneumothorax (n=1), detection of an airway-to-pneumothorax fistula (n=1) and exclusion of a suspected airway-to-mediastinum fistula (n=1). In all 4 patients, the additional findings had a substantial impact on patients' management. CONCLUSIONS: Xenon-enhanced DECT is safely feasible and can add relevant diagnostic information in mechanically ventilated intensive care patients with worsening respiratory function.
AU  - Högl, S.*
AU  - Meinel, F.G.*
AU  - Thieme, S.F.*
AU  - Johnson, T.R.*
AU  - Eickelberg, O.
AU  - Zwissler, B.*
AU  - Nikolaou, K.*
C1  - 11890
C2  - 30840
SP  - 557-562
TI  - Worsening respiratory function in mechanically ventilated intensive care patients: Feasibility and value of xenon-enhanced dual energy CT.
JO  - Eur. J. Radiol.
VL  - 82
IS  - 3
PB  - Elsevier
PY  - 2013
SN  - 0720-048X
ER  -