Adipose tissue MRI for quantitative measurement of central obesity.
OBJECTIVE
To validate adipose tissue magnetic resonance imaging (atMRI) for rapid, quantitative volumetry of visceral adipose tissue (VAT) and total adipose tissue (TAT).


METHODS
Data were acquired on normal adults and clinically overweight girls with Institutional Review Board (IRB) approval/parental consent using sagittal 6-echo 3D-spoiled gradient-echo (SPGR) (26-sec single-breath-hold) at 3T. Fat-fraction images were reconstructed with quantitative corrections, permitting measurement of a physiologically based fat-fraction threshold in normals to identify adipose tissue, for automated measurement of TAT, and semiautomated measurement of VAT. TAT accuracy was validated using oil phantoms and in vivo TAT/VAT measurements validated with manual segmentation. Group comparisons were performed between normals and overweight girls using TAT, VAT, VAT-TAT-ratio (VTR), body-mass-index (BMI), waist circumference, and waist-hip-ratio (WHR).


RESULTS
Oil phantom measurements were highly accurate (<3% error). The measured adipose fat-fraction threshold was 96% ± 2%. VAT and TAT correlated strongly with manual segmentation (normals r(2) ≥ 0.96, overweight girls r(2) ≥ 0.99). VAT segmentation required 30 ± 11 minutes/subject (14 ± 5 sec/slice) using atMRI, versus 216 ± 73 minutes/subject (99 ± 31 sec/slice) manually. Group discrimination was significant using WHR (P < 0.001) and VTR (P = 0.004).


CONCLUSIONS
The atMRI technique permits rapid, accurate measurements of TAT, VAT, and VTR.
Department of Radiology, University of Wisconsin, Madison, Wisconsin 53792-3252, USA.
Aziz H
AH
Poonawalla
Brett P
BP
Sjoberg
Jennifer L
JL
Rehm
Diego
D
Hernando
Catherine D
CD
Hines
Pablo
P
Irarrazaval
Scott B
SB
Reeder
D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000465:Algorithms; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D050152:Intra-Abdominal Fat / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D024821:Metabolic Syndrome / Q000473:pathology; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000473:pathology*; D050177:Overweight; D019047:Phantoms, Imaging; D012044:Regression Analysis; D015203:Reproducibility of Results; D055815:Young Adult