Purpose
The study aims to determine the role of Sound Touch Elastography [STE] technique in staging liver fibrosis and predicting clinically significant gastro-esophageal varices among patients with chronic liver disease [CLD] keeping aspartate aminotransferase to platelet ratio index [APRI] as the reference standard.
Methods
A prospective short-term study including 60 eligible patients with CLD were staged as non-significant fibrosis [NSF], significant fibrosis [SF] and cirrhosis [C] based on APRI values. STE was performed on each patient obtaining multiple readings as per pre-defined standards. The intra-observer reliability between each measurement and its association with APRI staging was evaluated using relevant statistical variables. Further, Youden’s index was used to define the optimum cut-off values on STE in differentiating the stages of fibrosis and in predicting clinically significant gastro-esophageal varices.
Results
Based on APRI cut-off values, 41.7% [n = 25] of the study population had cirrhosis, while 45% [n = 27] had significant fibrosis and 13.3% [n = 8] had NSF. The STE values in kPa showed a positive correlation with APRI values [(rs) = 0.837, p < 0.001]. The intra-class correlation estimates based on a mean rating [k = 5] was found to be 0.97 [0.95–0.99], implying an excellent agreement between the measurements. Optimum cut-off values in staging SF and C were 7.26 kPa [J = 0.73, sensitivity—85.19%, specificity—87.5%; 95% CI] and 13.79 kPa [J = 0.84, sensitivity—96.0%, specificity—88.89%; 95% CI]. The AUROC for each of these stages were 0.926 [0.785–0.987] and 0.976 [0.890–0.999], respectively. 23.3% [n = 14] of the study population had clinically significant gastro-esophageal varices with a value above 18.84 kPa [J = 0.88] showing a sensitivity of 92.85% and a specificity of 95.65% in predicting the same.
Conclusion
The novel STE technique shows good accuracy in staging liver fibrosis as determined by APRI values and in prediction of clinically significant gastro-esophageal varices with excellent reliability. It shows promising prospects and can be integrated widely in clinical practice for assessment and staging of fibrosis in CLD.
