Abstract
Background: Tetralogy of Fallot (TOF) is the most common cyanotic cardiac disease in children and is responsible for 7 -10% of all congenital abnormalities.MDCT has a limited role in the primary diagnosis of TOF, however, it plays an important role in accurate delineation of the intracardiac and extracardiac anomalies thus helps the treatment planning and improves the surgical outcome. This study aims to highlight role of MDCT angiography in OF variants and associated anomalies.

Patients and methods:Thirty patients (17 males and 13 females) with an age range of 3–74 months underwent MDCT cardiac angiography using 128-detectors Philips Healthcare Ingenuity scanner and Dual source Canon medical system incorporation, aquilion prime sp. scanner.
Results:The most common variant of Fallot was tetralogy of Fallot (66.7%) followed by pentalogy of Fallot (30%), and triology of Fallot (3.3%).Other variants include :double out let right ventricle (DORV) type Fallot (30%), Fallot with endocardial cushion defect (6.6%), Fallot with pulmonary atresia (26.7 %), and Fallot with absent pulmonary valve syndrome (3.3%).Associated intracardiac anomalies represent (33.3%), Systemic arterial abnormalities represent (23.3), Systemic venous abnormalities represent (23.3), Coronary arteries anomalies represent (3.3%). Associated Pulmonary arterial anomalies were found among46.7 % of cases.
Conclusion:MDCT cardiac angiography is a strong and indispensable modality in preoperative evaluation of TOF patients as it can delineate associated intracardiac and extracardiac anomalies. It provides complementary data to echocardiography regarding the pulmonary arteries, coronary arteries and tracheobronchial tree abnormalities.