Differential diagnosis of different types of solid focal liver lesions using two-dimensional shear wave elastography

BACKGROUND The clinical management and prognosis differ between benign and malignant solid focal liver lesions(FLLs), as well as among different pathological types of malignant FLLs. Accurate diagnosis of the possible types of solid FLLs is important. Our previous study confirmed the value of shear wave elastography(SWE) using maximal elasticity(Emax) as the parameter in the differential diagnosis between benign and malignant FLLs. However, the value of SWE in the differential diagnosis among different pathological types of malignant FLLs has not been proved.AIM To explore the value of two-dimensional SWE(2D-SWE) using Emax in the differential diagnosis of FLLs, especially among different pathological types of malignant FLLs.METHODS All the patients enrolled in this study were diagnosed as benign, malignant or undetermined FLLs by conventional ultrasound. Emax of FLLs and the periphery of FLLs was measured using 2D-SWE and compared between benign and malignant FLLs or among different pathological types of malignant FLLs.RESULTS The study included 32 benign FLLs in 31 patients and 100 malignant FLLs in 96 patients, including 16 cholangiocellular carcinomas(CCCs), 72 hepatocellular carcinomas(HCCs) and 12 liver metastases. Thirty-five FLLs were diagnosed as undetermined by conventional ultrasound. There were significant differences between Emax of malignant(2.21 ± 0.57 m/s) and benign(1.59 ± 0.37m/s) FLLs(P = 0.000), and between Emax of the periphery of malignant(1.52 ± 0.39 m/s) and benign(1.36 ± 0.44 m/s) FLLs(P = 0.040). Emax of liver metastases(2.73 ± 0.99 m/s) was significantly higher than that of CCCs(2.14 ± 0.34 m/s) and HCCs(2.14 ± 0.46 m/s)(P = 0.002).The sensitivity, specificity and accuracy were 71.00%, 84.38% and 74.24% respectively, using Emax > 1.905 m/s(AUC 0.843) to diagnose as malignant and 23 of 35(65.74%) FLLs with undetermined diagnosis by conventional ultrasound were diagnosed correctly.CONCLUSION Malignant FLLs were stiffer than benign ones and liver metastases were stiffer than primary liver carcinomas. 2D-SWE with Emax was a useful complement to conventional ultrasound for the differential diagnosis of FLLs.