Intra-operative application of real-time tissue elastography for the diagnosis of liver tumours

Objective: Real-time tissue elastography (RTE) has made it possible to visualize tissue elasticity. The aim of this study was to evaluate the usefulness of RTE for the differential diagnosis of liver tumours during surgical exploration. Methods: Fifty-five liver tumours in 44 patients were examined with RTE, concomitant with routine intra-operative ultrasonography. Elasticity images were classified into four types, from type A (even strain) to type D (no strain), according to the distribution and the degree of the strain contrasted with that of the surrounding liver [elasticity type of liver tumour (ETLT)]. We evaluated the consistency of the findings of RTE with the pathological diagnosis as a reference standard. Results: All malignant lesions showed various degrees of strain reduction in the tumour tissue. Twenty-one of 22 hepatocellular carcinomas (HCCs) were classified as type B with a sensitivity of 95.5%, a specificity of 90.9% and an accuracy of 92.7%, while all 24 metastatic adenocarcinomas were classified as either type C or type D with a sensitivity of 100%, a specificity of 80.6% and an accuracy of 89.1%. Conclusions: Application of RTE in surgical exploration provided significant information about the elasticity of liver tumours. RTE, using a new criterion, ETLT, enabled us to distinguish rather accurately between two common malignancies: HCC and metastatic adenocarcinoma.