abdominal fat - standarized technique for measurement at CT, Radiology 1999

ABSTRACT

The authors estimated abdominal fat distribution on the basis of measurements at computed tomography (CT). The attenuation range for fat tissue was defined as the interval within the mean plus or minus 2 SDs considered to be individual variation. Fat areas found with this method were closely correlated with those obtained by means of the computed planimetric method or with a fixed attenuation range from −190 to −30 HU as the standard of reference. Although the average CT numbers obtained with different scanners were distributed widely, the calculated fat areas were almost identical. This method might be a practical and standardized method at CT.

Abdominal obesity, as calculated with indexes such as the waist-to-hip circumference ratio, is related to metabolic disorders and hypertension and to an increased frequency of total mortality and cardiovascular disease (1–3). In recent years, intraabdominal visceral fat accumulation has been suggested as playing an important and etiologic role in these relationships (4–6). Computed tomography (CT) is an optimal technique for the accurate assessment of intraabdominal fat (7,8). We previously developed a method for measuring the fat volume in the human body by using this technique (7). Several studies revealed that visceral fat areas from a single scan obtained at the level of the umbilicus (approximately the level of L4 and L5) were highly correlated with the total visceral fat volume (7–9). Accordingly, a technique for the measurement of abdominal fat distribution based on findings at CT may be a practical and widely usable method for the evaluation of visceral fat accumulation, which is one of the most important cardiovascular risk factors. In the literature, however, several different attenuation ranges have been used to measure adipose tissue. Since the areas measured on the basis of different attenuation ranges may not be identical, we developed and evaluated a standardized method for measuring abdominal fat volume with CT.

Fat CT, Radiology 1999