Acute vasodilator response testing in the adult Fontan circulation using non-invasive 4D Flow MRI: a proof-of-principle study.

Background: Pulmonary vasodilator therapy in Fontan patients can improve exercise tolerance. We aimed to assess the potential for testing of acute vasodilator response using four-dimensional (D) flow MRI during oxygen inhalation.

Materials And Methods: Six patients with well-functioning Fontan circulations were prospectively recruited and underwent cardiac MRI.