Background: Functional single ventricle (FSV) is a rare and complex cardiac malformation. FSV is a broad term including various cardiac structural anomalies in which one ventricle is severely underdeveloped. We aimed to accurately diagnose FSV and its different subtypes using multidetector computed tomography (MDCT).

Methods: Eighteen patients with suspected FSV underwent cardiac computed tomography angiography (CTA), and the results were compared to those of echocardiography.

Results: MDCT could accurately diagnose FSV and its different subtypes. It detected FSV of left ventricular morphology in 77.8% with the most common associated subtype is double inlet left ventricle (DILV) and FSV of right ventricular morphology in 22.2% with double outlet right ventricle (DORV) as the commonest variant. MDCT was superior to echocardiography in defining the dominant ventricle in 22.2% of cases and detection of the associated extra-cardiac anomalies in 38.9% of patients. MDCT could assess the connection and state of palliative shunts in the 4 patients with earlier interventions.

Conclusion: MDCT can diagnose FSV and the associated extra-cardiac malformation and is indispensable in pre and postoperative follow up.

Keywords: FSV; MDCT; DILV; DORV.