Detection of steatosis in chronic hepatitis C, based on the evaluation of the attenuation coefficient computed on the ultrasound image

Abstract

Background and aims. The current study aims to evaluate the performance of the attenuation coefficient (AC)
in quantifying liver steatosis in a cohort of consecutive patients with chronic hepatitis C.
Methods. 189 consecutive patients with chronic HCV infection were prospectively included in this study. They
were referred to an ultrasound exam 1 day prior to liver biopsy, using the same device setting. The attenuation
coefficient (AC) was calculated on each image.
Results. AC values were significantly correlated with steatosis (r= -0.444, p<0.005), but there was no significant
correlation with activity (r=- 0.135, p=0.076) or fibrosis (r=- 0.066, p=0.367). The mean values of AC for each
steatosis grade were 0.0284 (no steatosis), -0.0284 (insignificant steatosis <33%) and -0.1140 (significant steatosis
≥33%) (p<0.001). A cutoff value of -0.0024 of AC could distinguish the fatty load <33% from no steatosis (Sn 75%,
Sp 61.76%, PPV 60.6%, NPV 75.9%, AUROC 0.734), and a cutoff value of -0.0546 could distinguish the significant
steatosis from the absent/insignificant one (Sn 84.21%, Sp 78.53%, PPV 31.4 %, NPV 97.7%, AUROC 0.842).
Conclusions. AC could be used to develop an imaging steatosis detection method in HCV infection. The extra
use of certain classifiers might increase the diagnostic performance of the method.