IVER FIBROSIS EVALUATION BY ACOUSTIC RADIATION FORCE IMPULSE IMAGING AND  THE ASPARTATE AMINOTRANSFERASE TO PLATELET RATIO INDEX IN CHRONIC HEPATIC DISEASE

Abstract

Background/Objectives: Acoustic radiation force impulse (ARFI) is a novel non-invasive technology for the assessment of liver fibrosis. Some studies previously reported that ARFI is a promising method for assessing liver fibrosis. Aspartaste aminotransferase (AST) to platelet ratio index (APRI) has been proposed as an easily determined and quite accurate noninvasive marker of liver fibrosis. This study aimed to explore the value of liver fibrosis assessment by ARFI, APRI and their combination in patients with chronic hepatic disease. Patients and Methods: The study was carried out on 119 patients with chronic hepatitis B, C, alcoholic liver disease and NASH. All of patients underwent a liver biopsy for histological assessment of liver fibrosis, ARFI elastography and calculate APRI. Cut-off values were determined using receiver-operating characteristic (ROC) curves. The corresponding cut-off values, sensitivities (Se), specificities (Sp), positive predict value (PPV) and negative predict value (NPV) were calculated and compared. In addition, the correlation of liver fibrosis stages with SWV and APRI were also tested to evaluate significant data. Results: Histological liver fibrosis was evaluated by Metavir scoring; F0: 9 cases, F1: 57 cases, F2: 23 cases, F3: 19 cases and F4: 11 case. SWV correlated significantly with the fibrosis stage (Spearman rho: 0.69, p = <0.0001). The areas under the ROC curves (AUROC) were 0.86 (95% CI: 0.79-0.93) for ≥F2 and 0.88 (0.80-0.96) ≥ F3. The cut-off values of SWV were as follows: ≥1.29 m/s for ≥F2 (Se 79.25%, Sp 89.36%, PPV 85.7% and NPV 84.3%), ≥ 1.36 m/s for ≥F3 (Se 96.67%, Sp 86.52%, PPV 70.7%, NPV 98.7%). APRI correlated with the fibrosis stage (Spearman rho: 0.35, p = 0.0001). AUROC were 0.7 (95% CI: 0.56-0.79) for ≥F2 and 0.7 (0.85-0.81) ≥ F3. The cut-off values of APRI were as follows: ≥0.569 for ≥F2 (Se 50.94%, Sp 88.33%, PPV 71.1% and NPV 67.9%), ≥ 1.163 for ≥F3 (Se 40%, Sp 96.63%, PPV 80%, NPV 82.7%). When both methods were taken into consideration, for predicting F ≥2, we obtained 45.3% Se, 100% Sp, 100% PPV, 69.5% NPV and 0,73 AUROC, while for predicting F ≥3 we obtained 40% Se, 98.9% Sp, 92.3% PPV, 83% NPV and 0.7 AUROC. When ARFI and APRI results agreed, F ≥2 was confirmed by liver biopsy in 45% of cases and F ≥3 in 43.3% of cases. Conclusions: Increasing SWV and APRI correlate with high degree of liver fibrosis. ARFI has a good accuracy with high specificities and NPV for prediction of significant and advanced fibrosis. APRI has a quite good accuracy with high specificities for prediction of significant and advanced fibrosis and high NPV for prediction of advanced fibrosis. The specificities and PPV of the combined tests were better than ARFI or APRI alone for predicting significant and advanced liver fibrosis. When these two methods are concordant in significant or advanced fibrosis, liver biopsy can be avoided. The methods should be employed routinely in the workup of patients with chronic liver disease to evaluate the presence of significant and advanced liver fibrosis. Key words: liver fibrosis, liver stiffness, chronic hepatic disease, acoustic radiation force impulse imaging (ARFI), the aspartate aminotransferase to platelet ratio index (APRI)