Agreement and correlation of abdominal skeletal muscle area measured by CT and MR imaging in cirrhotic patients

BACKGROUND: CT-based abdominal skeletal muscle area (SMA) serves as a standard for assessing muscle mass in patients with cirrhosis. Few studies have used MR imaging to measure SMA in cirrhotic patients. The purpose of this study was to investigate the agreement and correlation of the SMA measured by MRI and CT in cirrhotic patients. METHODS: CT and MR images from 38 cirrhotic patients were analyzed using the Slice-O-Matic V5.0 software. One observer independently measured SMA at the mid-third lumbar vertebral (L3) level on CT and MR images. The intraclass correlation coefficient (ICC), Pearson correlation coefficient, and Bland–Altman plot were used to evaluate the agreement and correlation between CT and MRI SMA and their relationship with the sarcopenia severity and Child–Pugh grades. RESULTS: CT and MRI had a high intraobserver agreement, with ICCs ranging from 0.991 to 0.996. CT and MRI measurements were closely correlated (r = 0.991–0.998, all for P < 0.01), and the bias of the measurements was 0.68–3.02%. Among all MR images, T1w water images had the strongest correlation (r = 0.998, P < 0.01) and the minimum bias of 0.68%. The measurements of mid-L3 SMA on CT and T1w water images remained highly consistent in cirrhotic patients with different severities of sarcopenia and Child–Pugh grades. CONCLUSIONS: MRI and CT showed high agreement and correlation for measuring mid-L3 SMA in cirrhotic patients. In addition to CT, MR images can also be used to assess muscle mass in cirrhotic patients, regardless of the severity of sarcopenia and Child–Pugh grades. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12880-022-00932-0.