Transforming Cardiac Imaging: Can CT Angiography Replace Interventional Angiography in Tetralogy of Fallot?

Background: Tetralogy of Fallot (TOF) is a complex congenital heart condition characterized by four major anatomical abnormalities. Accurate preoperative imaging is critical for optimal surgical outcomes, with transthoracic echocardiography (TTE), computed tomography angiography (CTA), and conventional catheter angiography (CCA) being the primary diagnostic tools. This study aimed to compare the diagnostic utility of TTE, CTA, and CCA in preoperative evaluations of TOF patients, focusing on anatomical parameters, imaging accuracy, and patient outcomes. Methods: A retrospective, single-center analysis included TOF patients under one year of age who underwent complete repair between January 2021 and December 2024. Preoperative imaging with TTE, CTA, and CCA was analyzed for parameters including pulmonary artery diameters, Nakata index, McGoon ratio, and Z-scores. Radiation exposure, procedure duration, contrast volume, and complications were documented. Statistical analyses were performed to assess the comparative accuracy and safety of these modalities. Results: All patients underwent TTE (n = 127), while CTA was performed in 86 patients and CCA in 41 patients. Among 127 patients, 62% were male, with a mean age of 5.81 ± 2.15 months. On TTE, CTA and CCA provided statistically similar measurements of the pulmonary annulus, main pulmonary artery, and branch diameters, with no significant differences in the Nakata index and McGoon ratio. CTA had a shorter procedure duration (3.1 ± 0.58 min) and lower radiation dose (1.19 ± 0.22 mSv) compared to CCA (20.73 ± 11.12 min; 5.48 ± 1.62 mSv). CTA successfully identified major aortopulmonary collateral arteries (MAPCAs) in 10% of patients and detected additional pulmonary pathologies, such as subsegmental atelectasis in 12%. Access site complications were observed in 10% of CCA cases but were absent in CTA evaluations. Conclusions: CTA emerges as a highly effective and non-invasive alternative to CCA for preoperative assessment of TOF, offering comparable anatomical accuracy with significantly reduced procedural risks, radiation exposure, and contrast volume. Combining TTE and CTA provides comprehensive diagnostic coverage, minimizing the need for invasive procedures and enhancing surgical planning. These findings underscore the evolving role of CTA in the management of congenital heart disease, contributing to improved patient safety and outcomes.