Acoustic radiation force impulse in the diagnosis of liver fibrosis in patients with chronic hepatitis B
In the study, the baseline characteristics of CHB patients were not provided. How about the alanine aminotransferase (ALT) levels and BMI of these patients? Recent studies have suggested that several factors such as ALT levels and BMI may influence the accuracy of ARFI elastography 2–4. A high BMI is significantly related to low diagnostic accuracy of ARFI elastography 2,3. Liver stiffness values assessed by ARFI are also influenced by high ALT levels 4. A multicenter retrospective study has revealed that mean liver stiffness values are significantly higher in patients with chronic liver disease with ALT more than five times the upper limit of normal as compared with those with normal ALT levels 4. Furthermore, the distribution of liver fibrosis stage of the CHB patients was not provided in the study. As shown in table 1, the CHB patients were not equally distributed according to their liver fibrosis stage. The number of patients with ≥F5 fibrosis was very low, which might have biased the results.
In addition, several studies have reported that the spleen stiffness values measured by ARFI elastography are correlated with fibrosis staging and could be used as a single predictor of stages of liver fibrosis in CHB patients 5–7. Thus, the study would have been strengthened if the authors had evaluated the performance of the spleen stiffness values measured by ARFI elastography in staging fibrosis in CHB patients.