Ultrasound Evaluation of Quadriceps Muscle Thickness in CKD

At T0 and at T2 (after twelve weeks), the patients underwent ultrasound evaluation of quadriceps rectus femoris thickness (QRFT) and quadriceps vastus intermedius thickness (QVIT) as this ultrasound approach seemed useful in the detection of muscle loss in CKD patients [43 (link),44 (link)]. This ultrasonographic evaluation was carried out by B-mode modulation with a 7.5 MHz transducer. The probe was placed perpendicular to the long axis of the muscle, which was covered with an abundant gel layer; minimal external pressure was exerted in order to prevent muscle compression. Three measurements were made bilaterally, in the supine position, with both knees in extension, at the level of two standardized points: the midpoint between the anterosuperior iliac spine and the upper limit of the patella and the boundary point between the lower third and the upper two-thirds of the quadriceps muscle. The values obtained were compared with the average of the measures evaluated in the reference population, as suggested by Sabatino et al. [45 (link),46 (link),47 (link)]. All ultrasounds were carried out by the same healthcare professional (A.N.) with an ultrasonographic experience of 15 years in order to reduce the bias related to intra-operator variability and with the same ultrasound equipment (Esaote MyLab70 XVision) with linear probe LA523.