A comparative analysis of CT angiography and echocardiography in the evaluation of chest findings in patients with interrupted aortic arch

Abstract

Interrupted aortic arch (IAA) is a rare congenital cardiovascular anomaly characterized by the absence of continuity between the ascending and descending aorta, often accompanied by congenital heart defects such as ventricular septal defects and patent ductus arteriosus. Accurate preoperative imaging is essential for surgical planning and patient management. This study aimed to compare the diagnostic accuracy of echocardiography and computed tomography angiography (CTA) in evaluating thoracic findings in patients with IAA. A retrospective analysis was conducted on 58 patients (median age: 18 days) diagnosed with IAA between September 2020 and January 2023 at the Heart Center, University Medical Center, Astana, Kazakhstan. Conventional echocardiography and multislice CTA were performed using standardized protocols. Sensitivity, specificity, and other diagnostic performance metrics were calculated. Statistical comparisons were made using McNemar's and Wilcoxon signed-rank tests, with p < 0.05 considered significant. Echocardiography correctly identified 91.4% of IAA cases, while CTA achieved 100% sensitivity and specificity. McNemar's test revealed a significant difference in diagnostic performance favoring CTA (p < 0.05). Measurements of the ascending aorta diameter showed no statistically significant difference between the two modalities (p = 0.09). IAA was predominantly type A (48.3%) and type B (46.6%), with hypoplastic ascending aorta identified in 34.5% of patients. Echocardiography remains a practical initial imaging modality for IAA, offering portability and cost-effectiveness. However, CTA demonstrated superior diagnostic accuracy and anatomical resolution, making it the preferred tool for detailed preoperative evaluation and surgical planning. Future studies with larger cohorts and additional modalities could further refine diagnostic strategies for IAA.

Keywords: computed tomography angiography; congenital heart defects; diagnostic imaging; echocardiography; interrupted aortic arch; surgical planning.

Figure 1

Echocardiographic images of a 7-day-old patient with type B IAA: (A) parasternal long-axis view shows the right ventricle (RV) and left atrium (LA) and the diameter of the ascending aorta (AAo) above the sinotubular junction; (B) parasternal short-axis view shows the right ventricle (RV), left atrium (LA), and the ascending aorta (AAo); (C) suprasternal notch view shows the brachiocephalic trunk (BT) and the left common carotid artery (LCC), followed by the echo signal disruption, corresponding to type B IAA.

Figure 2

CT angiographic multiplanar images of a 2-day-old patient with type B IAA: (A) axial plane shows the ascending aorta (AAo), followed by the patent ductus arteriosus (PDA), which connects the dilated pulmonary trunk (PT) and the descending aorta (DAo); (B) coronal plane shows the ascending aorta (AAo) and its branch brachiocephalic trunk (BT), next to which are the superior vena cava (SVC) and the enlarged pulmonary trunk (red arrow); (C) Maximum intensity projection of the reformatted sagittal aorta image shows an interrupted aortic arch just distal to the left subclavian artery origin (LS) and the pulmonary trunk (PT), which is connected to the descending aorta via the patent ductus arteriosus (PDA); (D) 3D reconstruction shows an interrupted aortic arch after the right common carotid artery (RCC) arises, and the left subclavian artery (LS) originates from the descending aorta, corresponding to type B IAA.

Figure 3

CT angiographic multiplanar images of a 55-day-old patient with type A IAA: (A) axial plane shows the branches of the aortic arch: brachiocephalic trunk (BT), left common carotid artery (LCC), and left subclavian artery (LS); (B) coronal plane shows that the ascending aorta branches into the brachiocephalic trunk (BT), which gives rise to the right common carotid artery. Also, the left common carotid artery (LCC) arising separately from the ascending aorta, the enlarged pulmonary trunk (PT), and its right branch are visualized; (C) Sagittal plane shows the pulmonary trunk (PT) continuing into the descending aorta via the patent ductus arteriosus (PDA); (D) 3D reconstruction shows an interrupted aortic arch after the left subclavian artery (LS) arises, corresponding to type A aortic arch interruption.