Acoustic Radiation Force Impulse (ARFI) imaging is an elastography method to evaluate tissue stiffness. This study aims to evaluate the use of ARFI to non-invasively determine if a liver mass is benign or malignant.Methods
This is a two-year cross-sectional study of patients with liver tumours who underwent liver elastography using ARFI at SLMC Quezon City (QC) and Global City (GC). All cases were diagnosed using histopathology, CT, MRI or ultrasound. Liver masses were grouped to either benign or malignant according to their aetiology, and the mean ARFI value per group were computed. Receiver operating characteristic (RUC) analysis was performed to evaluate the diagnostic accuracy of the ARFI measurement. The optimal cut-off value was chosen to maximise the sensitivity and specificity. A p value less than 0.05 was considered statistically significant.Results
Ninety cases of patients with liver mass with definite aetiology and who underwent ARFI were included. 23.3% of the patients had a history of other malignancy, and 35.5% had cirrhosis. 81.1% of the patients had malignant liver masses. Average ARFI value of malignant masses was 2.24 m/s while that of benign is 1.88 m/s (p=0.113). Based on the ROC curve, a cut off ARFI value of 1.965 m/s has the highest sensitivity and specificity to distinguish malignant from benign liver masses at 65.8% and 58.8%, respectively. Using a cut off ARFI value of 1.02 m/s, the sensitivity and specificity of diagnosing a liver mass to be malignant are 90.4% and 23.5%, respectively. The calculated positive likelihood ratio is 1.18 and negative likelihood ratio of 0.41.Conclusions
ARFI imaging is a promising method to characterise a liver mass as benign or malignant. It can accurately and objectively assess the stiffness of the liver mass in a non-invasive way. Any liver mass with an ARFI value of.