Abstract: Objective To investigate the application of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) in qualitative diagnosis of liver nodules and assessment of microvascular invasion. Methods A retrospective analysis was conducted on the clinical data of 337 patients with liver nodules admitted to the Qinhuangdao Second Hospital from February 2022 to January 2025. All patients underwent Gd-BOPTA-enhanced MRI scan. Pathological examination was used as the gold standard to analyze the diagnostic efficacy of Gd-BOPTA-enhanced MRI scan for benign and malignant liver nodules. According to pathological results, patients with malignant nodules were divided into positive and negative groups according to the situation of microvascular invasion. General information of the two groups and qualitative parameters of Gd-BOPTA-enhanced MRI scan were statistically analyzed. Multivariate logistic regression analysis was used to explore the influencing factors of microvascular invasion, and the receiver operating characteristic (ROC) curve was plotted to analyze the predictive efficacy of Gd-BOPTA-enhanced MRI scan for microvascular invasion. Results Pathological results showed that among the 337 patients, there were 266 cases of benign nodules and 71 cases of malignant nodules. Gd-BOPTA-enhanced MRI scan revealed 271 cases of benign nodules and 66 cases of malignant nodules among the 337 patients. The sensitivity, specificity, and kappa value of Gd-BOPTA-enhanced MRI scan for diagnosing the nature of liver nodules were 87.32%, 98.50%, and 0.881, respectively. Among the 71 patients with malignant liver nodules, there were 24 (33.80%) patients with microvascular invasion, while 47 (66.20%) had no microvascular invasion. The level of alpha fetoprotein in the positive group was significantly higher than that in the negative group (P<0.05). There were significant differences between the two groups in terms of peritumoral enhancement, condition of tumor edge, tumor capsule, and peritumoral low signal (P<0.05). Multivariate logistic regression analysis found that irregular tumor edge and peritumoral low signal were risk factors for microvascular invasion in patients with liver nodules (P<0.05). ROC curve analysis results showed that the areas under the curve (AUCs) for predicting microvascular invasion of liver nodules with qualitative parameters of irregular tumor edge and peritumoral low signal were 0.642 (95%CI: 0.519~0.752) and 0.791 (95%CI: 0.678~0.879), respectively. In addition, the AUC of peritumoral low signal was greater, with a sensitivity of 62.50% and a specificity of 95.74%. Conclusion Gd-BOPTA-enhanced MRI scan has good application value in qualitative diagnosis of liver nodules. Its qualitative parameters, including irregular tumor edge and peritumoral low signal, are risk factors for microvascular invasion in patients with liver nodules, and demonstrate good efficacy in predicting microvascular invasion of liver nodules.

Key words: Liver nodule, Enhanced magnetic resonance imaging scan, Gadobenate dimeglumine, Microvascular invasion, Qualitative diagnosis