Three steps approach for preoperative evaluation of tetralogy of Fallot patients: role of 128 MDCT

Background Tetralogy of Fallot is the most common congenital cyanotic heart disease. Advances in surgical repair recently facilitate survival of the affected patients into adulthood with good quality of life. Despite imaging plays crucial role in diagnosis of TOF patients, no single diagnostic modality suffices for complete evaluation of TOF. Thus, different diagnostic tools should be used alone or in combination according to patient’s clinical question. This study aims to find out the agreement between the echocardiography and MDCT in evaluation of TOF patients prior to surgical repair. Results Three-step approach used in scanning TOF patients. Firstly, classic TOF findings, MDCT was comparable to echocardiography in overriding aorta (k = 0.6), VSD (k = 0.8), RVH (k = 0.4), and sub valvular pulmonary stenosis (k = 0.6). Echocardiography is superior to MDCT in evaluation of valvular stenosis (k = 0.4). MDCT was superior to echocardiography in supravalvular pulmonary stenosis. Secondary, surgical relevant findings, McGoon ratio calculated in 94.2%, small and major APCs in 45.5% and 28.5% respectively, PDA in 35% and anomalous coronary artery in 5.1%. Thirdly, other TOF-associated anomalies, common: ASD (34.3%) and RAA (28.3%), and persistent LSVC (10.3%). Uncommon: situs ambiguous (2.5 %), PAPVR (1.2%), and IVC anomalies (3.8%). MDCT was superior to echocardiography in surgical relevant findings and other TOF-associated anomalies. Conclusion MDCT is a crucial imaging tool for extra cardiac evaluation of TOF patients prior to surgical repair.