Abstract:Background and Aims Microvascular invasion (MVI) is an important risk factor for early postoperative recurrence of hepatocellular carcinoma (HCC). For HCC accompanied by MVI, anatomic liver resection or hepatectomy with a wide resection margin may increase the elimination rate of MVI, thereby reduce the recurrence and improve the disease-free and overall survival of patients. However, the diagnosis of MVI is based on postoperative histopathology, so accurate preoperative prediction of MVI is of great value for the development of individualized treatment plans for HCC. The greatest advantage of gadolinium-ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) lies in the specific imaging performance during the hepatobiliary phase. Therefore, the Gd-EOB-DTPA enhanced magnetic resonance imaging (EOB-MRI) performed in the hepatobiliary phase can clearly show the boundary of the lesion, and greatly improve the ability of the lesion display and diagnosis. This study was conducted to analyzed the preoperative EOB-MRI imaging characteristics and determine its predictive value for MVI in HCC patients.Methods The clinicopathologic and imaging data of 147 HCC patients who underwent preoperative EOB-MRI examination and radical hepatectomy from July 2014 to June 2017 in the Department of Hepatobiliary Surgery of Drum Tower Hospital of Nanjing University were reviewed. The risk factors for MVI were analyzed, and the predictive effectiveness of EOB-MRI was determined.Results Among the 147 patients, 49 cases were MVI positive and 98 cases were MVI negative. The results of univariate analysis showed that tumor size (P=0.001), non-nodular type tumor on the hepatobiliary phase (P<0.001), peritumoral enhancement in arterial phase (P=0.016), rim enhancement in arterial phase (P=0.014), mixed signal intensity of tumor on hepatobiliary phase (P=0.001) and peritumoral hypointensity on hepatobiliary phase (P<0.001) were predictors for MVI. The results of multivariate analysis showed that non-nodular type tumor on hepatobiliary phase (OR=5.075, 95% CI=1.587-16.223, P=0.006), mixed signal intensity of tumor on hepatobiliary phase (OR=2.750, 95% CI=2.679-18.977, P=0.030), peritumoral hypointensity on hepatobiliary phase (OR=7.130, 95% CI=2.679-18.977, P<0.001) were independent predictors for MVI. For predicting MVI, the sensitivity of the three EOB-MRI imaging features (the gross type of tumor, mixed signal intensity of tumor on hepatobiliary phase and peritumoral hypointensity on hepatobiliary phase) was 89.8%, 57.1% and 61.2%, and their specificity was 51.0%, 72.4% and 89.8%, respectively. The specificity reached 98.0% by simultaneous presence of the three EOB-MRI imaging features.Conclusion Non-nodular type tumor, mixed signal intensity of tumor and peritumoral hypointensity on hepatobiliary phase are independent predictors for MVI. The simultaneous presence of the three EOB-MRI imaging features has a high specificity for predicting MVI.