Measurement of subcutaneous fat thickness with high frequency pulsed ultrasound: comparisons with a caliper and a radiographic technique.

This paper reports the use of a 10 MHz pulsed A-scan ultrasound system to measure the thickness of subcutaneous fat and its comparison with two other established techniques. Measurements using both ultrasound and Harpenden's skin calipers were made on the abdomen, over the scapula region, over the triceps and on the front of the thigh. Computerised axial tomography (CAT) was also used to obtain measurements of subcutaneous fat over the abdomen. In most instances the different techniques were significantly correlated. The ultrasound method showed non-dependency or bias upon the size of measurement when compared with the other two techniques. In addition, the ultrasound method was considered more accurate, reproducible and sensitive compared with the caliper technique and much more convenient than CAT scanning. However, the presence of septa at some sites in the more obese subjects was revealed by CAT scanning and made ultrasound assessment at these sites more difficult.