UNASSIGNED: The purpose of the study was to evaluate signal-fat-fraction (SFF)-analysis based on a 2-point-Dixon water-fat separation method in whole-body simultaneous PET/MRI for identifying brown adipose tissue (BAT) and discriminating it from @entity1386 ( @entity1386 ) using cross-validation via PET. METHODS: This retrospective, internal review board-approved study evaluated 66 PET/MRI-examinations of 33 pediatric @entity1 (mean age 14.7 years; range 7.4-21.4). Eleven elderly @entity1 were evaluated as control (mean age 79.9 years, range 76.3-88.6). Pediatric @entity1 were divided into two groups-with and without metabolically active supraclavicular BAT. Standard of reference for the presence of BAT was at least one PET-examination showing @entity419 -uptake. PET/MRI included a 2-point-Dixon water-fat-separation method. Signal intensities in ROIs on fat and water images and mean standardized uptake values (SUVmean) were determined bilaterally in supraclavicular and gluteal fat depots. SFF was calculated from the ratio of fat signal over summed water-and fat signal. Statistical analysis was conducted by using Student's t-test and correlation analysis. RESULTS: SFF was significantly lower (p<0.0001) in supraclavicular BAT compared to gluteal @entity1386 in all pediatric subjects. Supraclavicular SFF was significantly higher in the control than in the pediatric group (p<0.0001). In PET-positive @entity1 with multiple examinations, SFF stayed stable while SUVmean fluctuated (median intraindividual change 5% vs. 91%). No significant correlation between SUVmean and SFF could be observed for BAT. CONCLUSION: The results demonstrate that MRI-SFF-analysis is a reproducible imaging modality for detection of @entity1 BAT and discrimination from @entity1386 . SFF-values of BAT are independent from its metabolic activity, making SFF a more reliable parameter for BAT than the commonly used PET-signal. However, with intent to investigate both the composition of BAT as well as its activation status hybrid PET/MRI might provide supplementary information.

Discrimination between brown and XXXX using a two-point Dixon water-fat separation method in simultaneous PET/MRI.

@entity1 :: ('9606', 'Species') :: ['human', 'patients'] @entity419 :: ('MESH:D019788', 'Chemical') :: ['(18)F-FDG'] @entity1386 :: ('MESH:D018205', 'Disease') :: ['white adipose tissue', 'WAT']
@entity1386 :: (MESH:D018205,Disease) :: ['white adipose tissue']
