Validity of Ultrasound Imaging in Measuring Quadriceps Muscle Thickness and Cross-Sectional Area in Patients Receiving Maintenance Hemodialysis

Background: Muscle wasting, prevalent in maintenance hemodialysis (HD) patients diagnosed with protein-energy wasting, represents an assessment challenge in the outpatient HD setting. Quadriceps muscle thickness (QMT) and cross-sectional area (CSA) assessment by ultrasound (US) is a potential surrogate measure for muscle wasting. We aimed to determine the validity of US to measure QMT and CSA against the gold standard-computed tomography (CT).

Methods: Twenty-six patients on HD underwent US and CT scans on the same day, postdialysis session. QMT for rectus femoris (RF) and vastus intermedius (VI) muscles was taken at the midpoint (MID) and two-thirds (2/3) of both thighs and CSA of the RF muscle (RF_CSA ), respectively. Correlation between US and CT measurements was determined by intraclass correlation coefficient (ICC) and Bland-Altman plot.

Results: ICC (95% CI) computed between US and CT was 0.94 (0.87-0.97)_, 0.97 (0.93-0.99)_, 0.94 (0.87-0.97), 0.94 (0.86-0.97), and 0.92 (0.83-0.97) for RF_MID, VI_MID, RF_2/3, VI_2/3 , and RF_CSA , respectively (all P < 0.001). Bland-Altman analysis indicated no bias in agreement between both methods.

Conclusion: The US imaging offers a valid and quick bedside assessment approach to assess muscle wasting in HD patients.