Acoustic radiation force impulse elastography of the liver: Can fat deposition in the liver affect the measurement of liver stiffness?

摘要

Purpose. The aim of this study was to compare acoustic radiation force impulse (ARFI) results between livers with and without fat deposition. Materials and methods. We studied 200 consecutive healthy individuals who underwent health checkups at our institution. The subjects were divided into three groups according to the echogenicity of the liver on ultrasonography (US) and the liver-spleen attenuation ratio index (LSR) on computed tomography: normal liver group (n = 121, no evidence of bright liver on US and LSR > 1); fatty liver group (n = 46, bright liver on US and LSR < 1); others (n = 33, inconclusive results). Subjects in the inconclusive group and those who consumed alcohol >5 days a week (n = 18) were excluded from the analysis. The velocities measured by ARFI in the normal and fatty liver groups were compared using the two one-sided test. Results. The mean (SD) velocity measured in the normal and fatty liver groups were 1.03 (0.12) m/s and 1.02 (0.12) m/s, respectively. The ARFI results of the fatty liver group were similar to those of the normal liver group (P < 0.0001). Conclusion. This study suggested that fat deposition in the liver does not affect the liver stiffness measurement determined by ARFI.