How reliably can ultrasound help determine muscle and adipose tissue thickness in clinical settings? An assessment of intra- and inter-examiner reliability in the USVALID study.

Abstract

Ultrasound is used to measure muscle and adipose tissue thickness at the bedside. This study was aimed at determining the intra- and inter-examiner reliability for marking points to measure adipose tissue and muscle thickness and assessing it in terms of the performance and evaluation of the corresponding ultrasound scans. Intra- and inter-examiner reliability was tested in 120 patients. Limb lengths were measured to mark three and two measuring points on both the thighs and upper arms, respectively. Ultrasound scans were performed at each measuring point to evaluate muscle and adipose tissue thickness. Regarding the marking of the measuring points, intra- and inter-examiner reliability were high to very high, with correlation coefficients ranging from 0.74 to 0.96. In the performance and evaluation of adipose tissue thickness, all measuring points showed a high to very high reliability, with correlation coefficients ranging from 0.70 to 0.97. In the performance and evaluation of muscle thickness, the ventral measuring point on the thigh and the anterior measuring point on the upper arm showed the best reliability, with high to very high correlation coefficients ranging from 0.77 to 0.93. In terms of intra- and inter-examiner reliability, the ventral measuring point on the thigh and the anterior measuring point on the upper arm can be strongly recommended for ultrasound measurements of muscle and adipose tissue thickness.