Xiqi Zhu ^1* Jian Lv ² Xin Li ² Ronghua Mu ² Wei Zheng ² Peng Yang ² Bingqin Huang ² Fuzhen Liu ² Xiaomin Liu ³ Zhixuan Song ³ Xiaoyan Qin ²

• ¹ Department of Radiology, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
• ² Department of Medical Imaging, Nanxishan Hospital of Guangxi Zhuang Autonomous Region, Guilin, Guangxi Zhuang Region, China
• ³ Philips (China) Investment Co., Ltd., Guangzhou Branch, Guangzhou, China, Guangzhou, China

Background: In recent years, studies have confirmed the predictive capability of spectral computer tomography (CT) in determining microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC). Discrepancies in the predicted MVI values between conventional CT imaging features and spectral CT parameters necessitate additional validation.In this retrospective study, 105 cases of small HCC were reviewed, and participants were divided into MVI-negative (mean age, 59.40 ± 11.79 years) and MVI-positive (mean age, 58.74 ± 9.21 years) groups using pathological results.Imaging features and iodine density (ID) obtained from three-phase enhancement spectral CT scans were gathered from all participants. The study evaluated differences in imaging features and ID values of HCC between two groups, assessing their diagnostic accuracy in predicting MVI occurrence in HCC patients. Furthermore, the diagnostic efficacy of imaging features and ID in predicting MVI was compared.Results: Significant differences were noted in the presence of mosaic architecture, nodule-in-nodule architecture, and corona enhancement between the groups, all with p-values < 0.001. There were also notable disparities in IDs between the two groups across the arterial phase, portal phase, and delayed phases, all with p-values < 0.001.The imaging features of nodule-in-nodule architecture, corona enhancement, and nonsmooth tumor margin demonstrate significant diagnostic efficacy, with area under the curve (AUC) of 0.761, 0.742, and 0.752, respectively. In spectral CT analysis, the arterial, portal, and delayed phase IDs exhibit remarkable diagnostic accuracy in detecting MVI, with AUCs of 0.821, 0.832, and 0.802, respectively. Furthermore, the combined models of imaging features, ID, and imaging features with ID reveal substantial predictive capabilities, with AUCs of 0.846, 0.872, and 0.904, respectively.DeLong test results indicated no statistically significant differences between imaging features and IDs.Conclusions: Substantial differences were noted in imaging features and ID between the MVI-negative and MVI-positive groups in this study. The ID and imaging features exhibited a robust diagnostic precision in predicting MVI. Additionally, our results suggest that both imaging features and ID showed similar predictive efficacy for MVI.