Objectives To investigate the morphologic characteristics of intramural hematoma (IMH) on CT angiography (CTA), and evaluate the possible correlation of serum C-reactive protein (CRP) with morphologic characteristics of IMH. Material and Methods Forty-two patients who were initially diagnosed as IMH by aortic CTA and also had serum CRP examination on the same day of CTA were enrolled in this retrospective study, including 30 males and 12 females, with the mean age of 61 ± 14 years old. The volumetric CT data were retrospectively processed and analyzed on post-processing workstation. Based on the thickness of IMH and the length-area curve, the cross-sectional area of true lumen and total vessel were measured, the hematoma-vessel ratio (HVR) was calculated. Imaging characteristics were compared between patients who had pathological elevated CRP (> 0.8 mg/dl) and those did not. Spearman correlation analyses of CRP level and morphological characteristics of IMH were performed, and the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic validity of CRP. Results Of all 42 IMH patients, the mean serum CRP was 3.94 ± 4.71 mg/dl, and the mean HVR was 46.7%± 14.2%. HVR in patients with elevated CRP was significantly higher than those with normal CRP (49.7% ± 15.0% vs. 40.7% ± 10.5 %, P = 0.030). HVR was mildly correlated with CRP in all patients (r =0.48, P < 0.001). CRP levels differed neither between patients with Stanford type A and B (P = 0.207), nor between patients with and without intimal disruption (P = 0.230). To discriminate HVR > 47% (the mean value), the area under curve (AUC) were 0.700 (95% CI: 0.535-0.865) for CRP at a cutoff point of 3.55 mg/dl, with a sensitivity of 54.5% and a specificity of 90.0%. Conclusion CRP was mildly correlated with the severity of cross-sectional hematoma area of IMH, but not with Stanford types and the presence of intimal disruption.

Key words: CT angiography, C-reactive protein, intramural hematoma, acute aortic syndrome, morphology

Funding: Fund supported by the Clinical Research Supporting Fund of Chinese PLA General Hospital(2016FC-TSYS-1039)