Abstract P344: Comparison of Visceral Adipose Tissue Measurements in Adolescents Between Magnetic Resonance Imaging and DXA
Introduction: Excess Visceral Adipose Tissue (VAT) is linked to cardiometabolic risk in adolescents. VAT is mainly measured using Magnetic Resonance Imaging (MRI), yet dual-energy x-ray absorptiometry (DXA) is more affordable and available. The purpose was to compare VAT from MRI and DXA in adolescents. Methods: Adolescents 10-16 years of age were recruited. Abdominal MRI was performed using a General Electric (GE) Signal Excite scanner (3.0 Tesla; GE Medical Systems) with IDEAL-IQ imaging software. A series of scans between specific points on the liver and kidney were conducted. A trained technician manually drew VAT and used additional calculations to determine VAT volume (L). A whole-body DXA (GE iDXA scanner) was performed and software calculated VAT within the android region. Paired samples t-tests were used to determine differences between VAT values, within sex, race (White, African American, and Other race), and BMI categories (normal, overweight, and obese). VAT values were standardized to a mean of zero and unit standard deviation and compared with a Bland Altman plot. Results: A total of 330 adolescents participated. The mean age was 12.6±1.9 years, and the sample was 52.3% female, 58.5% White, 14.7% overweight (14.7%), and 33.5% obese. Average VAT from MRI (0.58±0.47 L) and DXA (0.35±0.41 L) significantly differed ( p =0.001). The error and absolute error were -0.23 ±0.20 L and 0.23±0.20 L respectively, with DXA measuring lower than MRI. DXA values were significantly lower from MRI values for each sex, race, and BMI categories ( p <0.01 for all). DXA values were closest to MRI values in African American adolescents (-0.14 ±0.20 L) and furthest away for those who had overweight (-0.31±0.17 L). All standardized values fell within ±1.96 standard deviations (Figure 1). Conclusions: In this sample, DXA measured VAT values were consistently lower overall and in subgroups compared to MRI. In general, DXA values were not comparable to MRI values.