Diagnostic accuracy of CT angiography in infants with tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries

Background: CT angiography (CTA) is increasingly used for the evaluation of congenital heart disease.

Objective: The aim was to determine the diagnostic accuracy of CTA in infants with tetralogy of Fallot with pulmonary atresia (ToF-PA) and major aortopulmonary collateral arteries (MAPCAs).

Methods: We retrospectively evaluated 18 consecutive patients (7 girls; median age, 6 days; range, 1-334 days) with ToF-PA and MAPCAs. Findings on CTA were compared with diagnostic catheterization (n = 16) or intraoperative findings (n = 2) for the number of MAPCAs, their diameter, origin, and supplied lung lobes and for the presence and diameter of central pulmonary arteries. Spearman correlation coefficient was calculated to assess the correlation between diameter measurements on CTA and catheterization. CTA dose-length product and catheterization dose-area product were recorded, and effective radiation doses were calculated with the use of age-specific conversion factors.

Results: Agreement was found between CTA and catheterization or intraoperative findings for the number of MAPCAs, their origin, and supplied lung lobes in all cases. In 11 of 13 patients, CTA accurately demonstrated central pulmonary arteries. A good correlation was found between diameter measurements on CTA and catheterization for MAPCAs (r = 0.83) and central pulmonary arteries (r = 0.82). Median effective doses were 0.9 mSv for CTA and 14.4 mSv for catheterization (P < .001).

Conclusion: CTA is accurate in the preoperative evaluation of infants with ToF-PA and MAPCAs and is associated with a substantially lower radiation dose than catheterization. Preoperative diagnostic catheterization, therefore, may only be necessary in select patients with small MAPCAs in whom the precise assessment of central pulmonary arteries is required for surgical planning.