Comparison between spleen and liver stiffness measurements by sound touch elastography for diagnosing cirrhosis at different aminotransferase levels: a prospective multicenter study

Objectives To compare the performance of spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by sound touch elastography (STE) for the diagnosis of cirrhosis at different alanine aminotransferase (ALT) levels, and to compare the applicability and repeatability of SSM with LSM performed by STE, a new two-dimensional shear wave elastography technology. Methods This prospective multicenter study included 25 centers and recruited chronic hepatitis B (CHB) patients with liver biopsy between May 2018 and November 2019. All patients underwent LSM and SSM by STE. Success and reliability rates were calculated and compared. Intra-observer agreement was assessed using intraclass correlation coefficients (ICCs). Differences between areas under the receiver operating characteristic curves (AUCs) of LSMs and SSMs at different ALT levels were compared using the Delong test. Results Among 603 CHB patients, the success and reliability rates of SSM were 94.53% (570/603) and 85.74% (517/603), respectively, which were similar to those of LSM ( p > 0.05), respectively. The ICC for intra-observer agreements of SSM was 0.964 ( p < 0.001). In the total cohort, ALT ≤ 2 × upper limit of normal (ULN) group, and A0–1 group, the AUCs of SSMs were significantly lower than those of LSMs for the diagnosis of cirrhosis ( p < 0.001). In the ALT > 2 × ULN group and A2–3 group, the AUC of SSM improved and was not significantly different from that of LSM ( p = 0.342, p = 0.510, respectively). Conclusions SSM by STE achieved applicability and repeatability equivalent to those of LSM. SSM might be a good substitute to LSM in patients with high ALT levels. Key Points • Spleen stiffness measurement performed by sound touch elastography was proven to have similar applicability and repeatability to liver stiffness measurement in this prospective multicenter study. • Spleen stiffness measurement demonstrated a poorer diagnostic performance for cirrhosis compared with liver stiffness measurement in the total cohort and low ALT level group, yet it showed a similar diagnostic performance to liver stiffness measurement in patients with high ALT levels.