Correlation of Ultrasound Acoustic Radiation Force Impulse Elastography with Sonographic Severity Grading of Fatty Liver Disease

Abstract

Introduction: Fatty liver is one of the commonly encountered incidental finding in routine ultrasonography practice. The fatty liver has been divided into three grades according to severity based on the degree of increased liver echotexture on ultrasonography. Ultrasonic elastography technique which measures liver stiffness is being used in quantitative and semiquantitative assessment of various liver conditions with few studies available on its role in fatty liver disease. Aim: To investigate the correlation of Acoustic Radiation Force Impulse (ARFI) elastography with ultrasound grading of the fatty liver disease. Materials and Methods: One hundred and nineteen patients were examined using B-mode ultrasonography and ARFI elastography and were divided in grade 0 (control group) and grade 1, 2, 3 according to severity of fatty liver. Ten successive ARFI readings were obtained from right lobe of liver and mean was considered the final ARFI value. Statistical analysis was performed using SPSS software, Version 20.0 with application of ANOVA test and t-test. Results: Total 119 patients, 68 males and 51 females were included in the study. Out of 79 patients of fatty liver, 39 patients had Grade 1 fatty liver, 29 patients had Grade 2 fatty liver, and 11 patients had Grade 3 fatty liver. Forty patients with normal liver were included in the control i.e., grade 0 group. The mean ARFI was 0.97±0.10 in grade 0, 1.24±0.14 in Grade 1, 1.38±0.16 in Grade 2 and 1.74±0.50 in Grade 3 groups. The difference between mean ARFI values between the control group and fatty liver group and also across various grades of fatty liver was found to be significant (p<0.001). The patients with a higher grade of fatty liver showed higher values on ARFI elastography. The difference between ARFI values in alcoholic and non-alcoholic fatty liver patients were not statistically significant. Conclusion: There was significant difference in ARFI elastography velocity measurements between normal and fatty liver patients. The difference between the mean ARFI values across the severity grades of fatty liver was also significant with higher ARFI elastography values seen in higher grades of fatty liver.

Keywords

• fibrosis
• hypertriglyceridemia
• liver stiffness
• steatosis