Clinical Use Of Low-dose Aortic CTA In The Prognostic Assessment Of Stanford Type B Intermural Aortic Haematoma

Objective:In this study,the quality of low-dose and normal-dose images of patients with IMHB was compared by using 128-row 256-layer spiral CT to investigate the feasibility of low-dose aortic CTA for the diagnosis of IMHB.The aim is to investigate the feasibility of low-dose aortic CTA for the diagnosis of IMHB and to further investigate the value of low-dose aortic CTA in the prognostic evaluation of IMHB.Methods:A total of 203 patients who underwent aortic CTA at our radiology department from September 2019 to December 2022 and were diagnosed with IMHB by clinical and imaging findings were selected.Based on the general data,clinical history and imaging images,152 patients were finally enrolled,of whom 107 were male and 45 were female.The patients enrolled were divided into a low-dose group and a normal-dose group according to the scanning protocol at the initial visit.The feasibility of low-dose aortic CTA for the diagnosis of IMHB was analysed by comparing the image quality.The patients enrolled were divided into surgical and pharmacological groups according to their treatment modality,and the prognostic differences between the two groups were analysed.Patients treated with pharmacological therapy alone were retrospectively analysed,and the ROC curve was used to estimate the threshold value of the initial hematoma thickness in the same level of the lumen that led to the patients’ prognostic progression.Finally,the patients enrolled were divided into stable and progressive groups according to their prognosis to investigate whether PAU was an influential factor in patients’ prognosis.Results:1 The differences in mean CT values between the images of patients in the low-dose group and the normal-dose group were not statistically significant(P > 0.05)for the six measurement points: ascending aorta at the level of the pulmonary trunk,descending aorta at the level of the pulmonary trunk,abdominal aorta at the level of the superior mesenteric artery,abdominal aorta at the level of the inferior mesenteric artery,right common iliac artery,and right and left lumbaris major muscle in the L4 plane.The differences in subjective scores,SNR and CNR between the two groups of images were not statistically significant(P > 0.05).The values of radiation dose-related indicators were significantly reduced in the low-dose group compared to the normal-dose group,and the difference between the two groups was statistically significant(P < 0.05).2 The prognosis of patients in the surgical group was more stable and less progressive than in the drug group,with a statistically significant difference between the two groups(P < 0.05).The reduction in haematoma after 1 year was 58.3% in the surgical group and 28.6% in the drug group,with a statistically significant difference between the two groups(P < 0.05).The sensitivity and specificity of using 31.5% of haematoma at initial diagnosis as the threshold value for predicting prognostic progression in patients treated with drugs was the highest,with a sensitivity of 78% and a specificity of 79.2%.3 The proportion of PAU in the stable and progressive groups was(35.85% and 58.54%)after drug treatment and(18.18% and 57.14%)in the stable and progressive groups,respectively,after surgical treatment,and the proportion of PAU in the progressive group was significantly higher than that in the stable group regardless of the treatment modality,with a statistically significant difference between the two groups(P < 0.05).Conclusions:1 Low-dose aortic CTA can clearly show the aorta and its branch vessels,which not only meets the diagnostic requirements of IMHB but also reduces the radiation dose received by the patient,which is of great significance in reducing radiation damage to the patient’s body.2 Patients with IMHB treated surgically have a better prognosis than those treated with drugs alone.At the initial diagnosis of an aortic intermural haematoma with a thickness of more than 31.5% of the aortic lumen at the same level,the prognosis for patients treated with medication is poor,with a tendency for disease progression.3 PAU has an adverse effect on the prognosis of patients with IMHB,and treatment should be taken early and monitored clinically in IMHB patients with combined PAU.