Comparison of two techniques for measurement of visceral adipose tissue cross-sectional areas by computed tomography

Most computed tomography (CT) scanners used today are able to accurately measure adipose tissue (AT) areas at any site of the body. However, first generation CT scanners used by some medical centers are not equipped with appropriate software allowing the measurements of AT areas. The aim of this study was to validate a technique of AT area measurements independent from CT scanner software. Abdominal AT areas were recorded with CT in a sample of 30 men. Areas were thereafter calculated using the standard CT software technique. Total and visceral AT areas were then remeasured using another technique for which X-ray film of each subject's scan was analysed by a system completely independent from the CT scanner (imaging densitometer and NIH image analysis software). Correlations between measurements obtained with the two techniques were very strong for both total (n = 0.99; SEE 11.7 cm(2)) and visceral AT areas (r = 0.99; SEE = 5.3 cm(2)). Values obtained with the image analysis method were generally higher than with the conventional CT software technique (cross-sectional areas of AT were overestimated by 4.7% for total abdominal and 8.5% for visceral AT respectively). In conclusion, the results indicate that measurements obtained with this image analysis technique would be adequate to correctly rank subjects according to levels of total or visceral AT areas. However, since this method appears to slightly overestimate AT areas, a standardized correction should be performed before comparing subjects with AT areas measured with this technique to subjects whose AT areas have been obtained with the conventional CT software technique. (C) 1999 Wiley-Liss, Inc.