Quantitative Assessment of Muscular Stiffness in Children With Chronic Kidney Disease Using Acoustic Radiation Force Impulse Ultrasound Elastography.

The aim of this study was to evaluate the feasibility of quantitative analysis of muscle stiffness in the rectus femoris muscle (RFM) by acoustic radiation force impulse (ARFI) ultrasound elastography in children with chronic kidney disease (CKD). Twenty-three children with CKD and 22 healthy children participated in the study in our radiology department. The strength of each CKD group and healthy group participants' tight extensors was assessed by a physiatrist using a handheld dynamometer. Acoustic radiation force impulse was used to measure the shear wave velocities (SWVs) of the RFM. The mean SWV value of the RFM correlated with the strengths of the tight extensors in the CKD and healthy groups. The mean ± SD SWV values of the RFM in the CKD group for the right (n = 23) and left sides (n = 21) were 1.23 ± 0.25 and 1.26 ± 0.30 m/s, respectively. The mean ± SD SWV values of the RFM in the healthy group for the right (n = 23) and left sides (n = 21) were 1.62 ± 0.33 and 1.65 ± 0.35 m/s, respectively. The SWV of the RFM significantly decreased in the patients with CKD when compared with controls (P < 0.001). The SWV values were not correlated to the handheld dynamometry. The interobserver agreement expressed as the interclass correlation coefficient was 0.65 (95% confidence interval, 0.33-0.84; P < 0.001). The acoustic radiation force impulse demonstrates a difference in RFM muscle stiffness between the CKD and healthy groups. This method is a feasible imaging method for the noninvasive assessment of muscle weakness in children with CKD.