Standard Ultrasound Examination of the Liver Does Not Correlate with APRI Score or Histological Level of Fibrosis in a Population with Hepatitis C

Abstract

Purpose: In the management of patients (pts) with liver disease, ultrasound (US) examinations of the liver are commonly ordered to estimate hepatic fibrosis as well as to monitor the development of hepatocellular cancer in patients with chronic hepatitis C (HCV). Our aim was to test the utility of US to detect fibrosis in a group of patients with chronic hepatitis C who have undergone determination of the aspartate aminotransferase/platelet ratio index (APRI) score and liver biopsy Methods: Out of the pool of pts examined at our institution within the last year, 195 have had an ultrasound examination within 6 months of a pretreatment staging liver biopsy. 9 patients with HIV co-infection, 1 patient with autoimmune hepatitis and 12 patients with Hepatitis B were excluded, because the APRI and histological fibrosis scores have not been validated in these groups. 54 pts had incomplete data. Thus, 119 patients were studied: APRI <0.4 = 17, 0.4–1.5 = 75, >1.5 = 27. The following ultrasound criteria were utilized: Liver size: small, normal, or enlarged; nodularity: + or -; echogenicity: normal, increased or coarse; spleen size: normal or >12 cm = enlarged; Liver biopsy fibrosis was scored 0–4 on the Batts-Ludwig scale. Data was analyzed using SAS 9.1® statistical software. Results: The correlation coefficient between fibrosis stage and APRI across all values was 0.505 (P < .0001). Limiting the APRI to the indeterminant range (0.4–1.5), the score was 0.460 (P < .0001). The correlation coefficient between fibrosis stage and ultrasound score was 0.167 (P= 0.069, ns) for all stages of fibrosis and 0.372 (P= 0.0278) when limited to stage 3 and 4 fibrosis on biopsy. Limiting to APRI between 0.4–1.5, the correlation between ultrasound score and fibrosis was 0.099 (P= 0.398). Conclusion: Confirming previous studies, The APRI score significantly correlates with fibrosis stage when all samples are compared or when the comparison is limited to APRI values in the indeterminant range (0.4–1.5). In contrast the ultrasound score correlates with fibrosis score only in patients with advanced fibrosis. The addition of ultrasound score to APRI does not improve correlation with fibrosis score. Examination of traditional criteria for evaluation of liver ultrasound studies does not add significantly to the detection of hepatic fibrosis over and above APRI, in patients with well compensated chronic hepatitis C.