Evaluation of 2D- Shear Wave Elastography for Characterisation of Focal Liver Lesions.

Background & Aim: This is a prospective study for evaluation of 2D-shear wave elastography (2D-SWE) for characterisation and differentiation of benign and malignant focal liver lesions (FLLs). Methods: The patients referred to our ultrasound unit were prospectively included. B-mode ultrasound and 2D-SWE (Aixplorer*France) were performed for one FLL in each patient. Liver histology and/or contrast enhanced imaging were used as a reference method. Results: 140 patients with FLL were included. SWE acquisitions failed in 24% of them. Therefore, 106 patients with FLL could be analysed, 42/106 with benign and 64/106 with malignant FLLs. The median stiffness for benign FLLs was 16.4 (2.1-71.9) kPa: 16.55 kPa for 18 focal nodular hyperplasia (FNH), 16.35 kPa for 18 hemangioma, 9.8 kPa for 3 focal fatty sparings (FFS), 8.9 kPa for 1 adenoma, 20 kPa for one regenerative node and 29 kPa for one cholangiofibroma, and for the malignant FLLs 36 (4.1-142.9) kPa: 44.8 kPa for 16 hepatocellular carcinoma (HCC), 70.7 kPa for 7 cholangiocarcinoma (CCC) and 29.5 kPa for the 41 metastasis (p<0.001). Malignant FLLs were significantly stiffer than benign FLLs (p<0.0001). Cholangiocarcinomas were the stiffest malignant FFLs with significantly higher values as compared to HCCs and metastases (p=0.033 and p=0.0079, respectively). No significant difference in stiffness could be observed between the different benign FLL entities. No significant difference was observed whether 2D-SWE included the whole FLL, the periphery or only the hardest area of the FLL. Conclusions: 2D-SWE provides further characterising information for interpretation of FLLs and may be useful at least in differentiation of CCCs and HCCs.