Feasibility of three-dimensional CT axial sequence assisted volumetric measurement for atrial septal defect evaluation / 中华放射学杂志

ABSTRACT

Objective:To explore the feasibility of three-dimensional CT axial sequence assisted volumetric measurement (CTAS) in evaluating atrial septal defect (ASD).Methods:The patients with single secundum ASD who successfully underwent interventional therapy in Fuwai Hospital from January 2016 to December 2019 were retrospectively collected. The patients underwent coronary CT angiography (CTA) before and on the second day after closures, and DSA examinations during operation. A total of 52 cases met the inclusion conditions, among them, there were 37 patients with large defects which had deficient inferior rims ≤3 mm, and 15 patients with severe pulmonary arterial hypertension that occluded with fenestrated ASD occluder. The CT data of patients before and after operation were reconstructed by CTAS. Then the anatomical structure of ASD before the operation was evaluated, including the long diameter and short diameter of ASD, and the CT three-dimensional volume diameter of ASD was calculated by using the equivalent circle conversion formula of ellipse. The waist diameter of occluder and rims of the ASD were measured after occlusion on postoperative CT three-dimensional volume reconstruction images. Meanwhile, the deployed occluder waist dimension was measured in DSA examination during the operation by simulating the balloon measurement of ASD. Lastly, paired t-test and consistency analysis were carried out among the values of parameters. Results:Before operation, the equivalent circle diameter of ASD was (32.3±5.4) mm measured by CTAS. After ASD occlusion, the size of the waist dimension measured by DSA and CTAS were (32.5±4.9) mm and (32.6±4.9) mm. There were no significant differences between them ( P>0.05). There were also no significant differences for each rims of the ASD pre and post operation on CTAS except for the inferior rims and the total length of atrial septum in superior-inferior direction ( P>0.05). Conclusion:As an alternative to balloon sizing, CTAS can be used as a reference standard to conduct ASD interventional treatment.