Clinical Application Of Spectral CT Multi-parameter Characteristics In Predicting Microvascular Invasion Of Hepatocellular Carcinoma

Objective: To explore the feasibility of using spectral CT multi-parameter features to predict microvascular invasion（MVI）in hepatocellular carcinoma（HCC）.Methods:A retrospective analysis of 40 patients with hepatocellular carcinoma who were admitted to the First Hospital of Lanzhou University and confirmed by pathological biopsy from December 2020 to January 2022 were retrospectively included and analyzed,complete clinical and laboratory data were collected from patients’ medical records.According to the postoperative pathological results,the patients were divided into two groups: microvascular invasion group and non-microvascular invasion group.All patients were scanned by epigastric spectral CT within one week before operation.The holographic spectral images of patients were obtained by Philips ISP software.the iodine concentration（IC）,effective atomic number and CT values corresponding to 40,70 and 90 Ke V in aortic phase and portal phase were measured respectively,and the standardized iodine concentration（NIC）,venous iodine uptake reduction rate（ICrr）and slope of energy spectrum curve were calculated.The differences of clinical and laboratory data and spectral quantitative parameters between the two groups were evaluated by independent sample t-test,Mann-Whitney U test,chi-square test or Fisher exact probability method.ROC characteristic curve was used to analyze the parameters with statistical differences to evaluate the diagnostic performance of HCC microvascular invasion.The CT values obtained by simulating conventional CT scanning with 70 ke V images were compared with those corresponding to 40 ke V images.Results: 1.There were significant differences in serum alpha-fetoprotein（AFP）,arterial phase iodine concentration（IC）,standardized iodine concentration（NIC）,slope of energy spectrum curve,effective atomic number and reduction rate of venous phase iodine uptake ratio（ICrr）between patients with microvascular invasion and those without microvascular invasion（p<0.05）.2.The ROC characteristic curve showed that the standardized iodine concentration（NIC）in the arterial phase had the highest diagnostic performance in judging HCC microvascular invasion.Using 0.15 as the threshold for NIC,one could obtain an area-under-curve（AUC）of 0.87 in ROC to differentiate between tumours with and without microvascular invasion,the index demonstrated sensitivity of 87.50%,specificity of 81.20%.3.There was no significant difference in the CT value at the 70 Kev single energy level in the arterial phase between the invasion group and the non-invasive group（P>0.05）;and the AUC value measured by the CT value at 70 ke V was lower,which was 0.617.When the energy level is adjusted to 40 ke V,the AUC increased to 0.862.Conclusion:1.There was a significant difference in preoperative serum AFP content between the microvascular invasion positive group and the microvascular invasion negative group,and when AFP ≥545.5ng/ml,the patients were more likely to have MVI.2.The quantitative parameters of spectral CT are helpful to the microvascular invasion of hepatocellular carcinoma,especially the arterial standardized iodine concentration（NIC）has the greatest potential application value in judging whether there is microvascular invasion or not,and can provide an important reference for clinical treatment and prognosis evaluation.