Texture-based Differentiation Of Focal Liver Lesions Based On Contrast-enhanced MRI Images

Objective: Intrahepatic cholangiocarcinoma(ICC),hepatic metastases(HM)and liver abscess(LA)are regarded as the main malignant tumors and benign lesions of the liver.MRI is a noninvasive imaging method commonly used to assess liver diseases,but its diagnostic accuracy is limited.Texture analysis(TA)is the hot spot of attention for radiologists.This study aims at assessing the feasibility of texture analysis based on contrast-enhanced MRI images for the classification of focal liver lesions,and to explore the value of differential diagnosis in ICC,HM and LA.Methods: The MRI data of 120 patients with pathologically proven ICC(n=40),HM(n=40)and LA(n=40)were retrospectively analyzed.We used two independent cohorts for training(n = 60 patients)and validation(n = 60 patients).Contrast-enhanced MRI scan was performed in all patients.The TA was performed and textual features were derived from free software Ma Zda,the Lasso regression was used to select texture features and construct the Lasso-Logistic modles,and calculate the area under the curve(AUC);the modles were verified with the validation group,and calculate the misclassification rate(MCR)of each group of lesions.Results: 1.All the texture feature parameters selected by the Lasso method showed statistical difference(P<0.05)between the 2 discriminant groups(benign and malignant FLLs,two types of malignant FLLs).For the identification of benign and malignant FLLs,the Lasso-logistic model based on delayed phase images is better than that based on T2 WI,arterial phase and portal venous phase images(AUC = 0.903,0.751,0.818 and0.837);for the classification of two types of malignant FLLs,the Lasso-logistic model of arterial phase images has best effect,followed by that based on the portal venous phase,delayed phase and T2 WI images(AUC = 0.926,0.895,0.857 and 0.769).2.For the 60 cases in the validation group,the TA based on three phase contrast-enhanced MRI images had lower misclassification rate(MCR)of differentiation(31.5%-35%)compared with that based on T2 WI images(10%-18.3%).In the differential diagnosis of benign and malignant lesions,the MCR of texture analysis based on delayed phase images(10%)is lower than that based on T2 WI,arterial phase and portal venous phase images(31.5%,18.3%,15%);for the differential diagnosis of two malignant lesions,texture analysis based on arterial phase images has lowest MCR(12.5%)compared with other phases images: 35%(T2WI),15%(portal venous phase)and 20%(delayed phase).Conclusion: To sum up,for the identification of benign and malignant FLLs with texture analysis,the differential diagnostic efficiency of three phase contrast-enhanced MRI images are better than that of T2 WI images.The results of this study show the possibility of differentiating different pathological types of liver lesions based on contrast-enhanced MRI images’ texture analysis.As a noninvasive auxiliary diagnostic method of FLLs,texture analysis has achieved good results in differential diagnosis,so it has some clinical utility.