The Value Of Dual-energy CT Quantitative Parameters In Differentiating Spontaneous Intramural Hematoma And Atherosclerosis Of Carotid Artery

Objective:To evaluate the value of dual-energy CT（DECT）quantitative parameters in differentiating carotid artery spontaneous intramural hematoma from atherosclerosis.Methods:The quantitative parameters of dual-energy CTA images of 14 patients with carotid spontaneous intramural hematoma and 56 patients with atherosclerosis who underwent dual-energy CTA examination and were confirmed by HR-VWI examination or follow-up in the First Hospital of Shanxi Medical University from September 2018 to March 2021 were retrospectively analyzed.The clinical data of the patients were recorded.Two radiologists with 5 and 8 years of diagnostic experience measured the quantitative parameters of dual-energy CT.Including conventional CT value,normalized iodine concentration（NIC）,normalized effective atomic number(Z_eff-C),fat fraction,energy spectrum curve slope(λ_HU),virtual non-contrast CT value（VNC）and virtual non-contrast CT value difference between the lesion and the lumen(VNC_ΔCT).Finally,the mean value of the data measured by two radiologists was analyzed.normally distributed variables of Dual-energy quantitative data were compared by independent samples t test,and non-normally distributed ones by the Mann-Whitney U test between the two groups.The quantitative parameters with statistically significant differences were incorporated into binary logistic regression for multi-factor analysis to obtain independent predictors for the identification of the two diseases.Drawing the receiver operating characteristic（ROC）curve to evaluate the diagnostic performance of carotid hematomas and atherosclerosis,and calculating the corresponding sensitivity and specificity.Results:A total of 70 patients were selected in this study,including 14 patients in the intramural hematoma group,with a total of 14 diseased vessels,all located in the extracranial segment,8internal carotid arteries in the left and 5 internal carotid arteries in the right,and one common carotid artery in the right and one in the internal carotid artery.The 56 patients in the atherosclerosis group had 56 diseased vessels,all located in the extracranial segment,21carotid arteries in right internal,17 internal carotid arteries in left,11 common carotid arteries in left,and 7 common carotid arteries in right.The study showed that NIC in the atheroma group was significantly higher than that in the intramural hematoma group,while VNC_ΔCT was significantly lower the intramural hematoma group,with statistical significance（P<0.05）.NIC and VNC_ΔCT can be used as independent predictors for differentiating intramural hematoma from atherosclerosis.The area under the curve（AUC）of NIC,VNC_ΔCT and the combination of two parameters were 0.83,0.76 and 0.88,respectively.,the sensitivity was 78.6%,71.4%and 85.7%and the specificity was 83.9%,78.6%and 83.9%,respectively.Conclusion:The NIC and VNC_ΔCT have better diagnostic performance in differentiating carotid spontaneous intramural hematoma from atherosclerosis,which provide a new objective imaging evidence and certain clinical application value.