Investigation of an appropriate contrast-enhanced CT protocol for young patients following the Fontan operation

Children with congenital heart diseases (CHDs) may need to be followed up with contrast-enhanced CT following the Fontan operation because complications such as the occlusion of conduits may occur. The purpose of the present study was to develop an adequate contrast-enhanced CT protocol for children with CHD following the Fontan operation. Between July 2012 and July 2017, 29 CT examinations for 26 patients aged 2–11 years (median 5 years) with CHD following the Fontan operation were performed using dual-source CT. A non-ionized contrast medium was injected through the dorsum manus vein. Scanning began 60 or 70 s after the start of the injection. The delayed phase was randomly selected to be 60 s in 14 cases and 70 s in 15 cases. We evaluated the enhancement of conduits following the Fontan operation at delayed phases. The CT numbers of conduits at 60 and 70 s were 185 ± 46 and 185 ± 31 HU, respectively (P = 0.97). In contrast-enhanced CT for children after the Fontan operation, both of the delayed phases (60 and 70 s) appeared to be adequate for evaluating intraconduit patency.