Comparison of Shear-Wave Elastography USG and CT: Composition Analysis of Rectus Femoris Muscle in Healthy Adults and Chronic Kidney Disease Patients.

PURPOSE

This study aimed to compare shear-wave elastography (SWE) USG and composition analysis of CT on the right mid-rectus femoris muscle (RF) in both healthy adults and chronic kidney disease (CKD) patients.

METHODS

Sixty-three healthy adults and 22 CKD patients were included. One musculoskeletal radiologist performed right RF SWE USG, while two radiologists measured shear-wave velocity (SWV) from the same SWE images. CT scan was performed, and muscle composition was measured using imageJ, categorized into four HU-based compositions. Interobserver agreement for SWV between two readers was evaluated. Correlations between SWV and CT compositions were analyzed using Pearson's or Spearman's correlation.

RESULTS

SWV of healthy group was significantly higher than CKD group by each reader (p = 0.030 and 0.038). The percentage of low-density muscle was higher in CKD group than healthy group (p < 0.001), and the percentage of normal density muscle was higher in healthy group than CKD (p < 0.001) by each reader. Interobserver agreement of SWV by the two readers was almost perfect in both groups (k = 0.957-0.984, 0.959-0.993). There was a statistically significant correlation between SWV and the percentage of normal density muscle on CT in both healthy adults and CKD patient groups (Reader 1, r = 0.318-0.480, p = 0.001 and 0.024; Reader 2, r = 0.511-0.518, p < 0.001 and p = 0.013).

CONCLUSIONS

SWV demonstrated a significant correlation with the percentage of normal density muscle on CT in both healthy adults and CKD patients by each reader. SWE provides a radiation-free approach that may offer an objective method for evaluating muscle quality, potentially making it an option for muscle monitoring.