CT Assessment of Muscle Mass and Quality for Hip Surgery: A Feasibility Study

Purpose: The segmentation of psoas muscles at L3 is used to measure muscle mass and quality, and thus estimate sarcopenia status and body composition with a single cross-sectional computed tomography (CT) slice. However, this parameter is not useful when CT is performed in other areas for other issues. Our aim was to correlate estimation of muscle mass around the hip with that obtained using psoas segmentation at L3 on CT scans.

Methods and Materials: A radiologist reviewed unenhanced abdominal CT scans performed in 50 consecutive patients (29 men; mean age: 69.6 ± 11 years; range: 37–87 years). Regions of interest were drawn manually to assess the cross-sectional area (CSA) and attenuation of the psoas muscles at the L3 level, which was considered the standard. These values were correlated with CSA and attenuation of iliopsoas, rectus femoris, sartorius, and tensor fascia latae at the level of the hip, separately on each side. After applying Bonferroni correction for multiple comparisons, statistical significance was set as p < .002.

Results: The mean CSAs of the right and left psoas at L3 were 699.3 ± 206 mm² and 759.1 ± 264 mm², respectively; attenuation values were 35.5 ± 8.7 HU and 35.6 ± 7.9 HU, respectively. We found a significant correlation between attenuation values of both psoas at L3 and those of all the other muscles measured at the hip (p < 0.001; r > 0.491). A significant correlation was also observed between CSA of the right psoas and that of all the other muscles (p ≤ 0.001; r > 0.459), except for the tensor fascia latae at the lesser trochanter (p = 0.004; r = 0.401). We also observed a significant correlation between CSA of the left psoas and that of the left psoas at the top of the femoral head and rectus femoris (p = 0.001; r = 0.456), with no significant correlation with tensor fascia latae and sartorius (p ≥ 0.002; r ≤ 0.430).

Conclusion: Measurements of mass and quality of muscles around the hip are highly correlated with those performed on the psoas at the L3 level. These measurements could be applied in future studies to evaluate sarcopenia in patients undergoing hip surgery using routinely performed scans without additional imaging.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
17 December 2020