Pulmonary regurgitation (PR) is the most common complication after repaired Tetralogy of Fallot (TOF).
They used 4D-flow MRI to investigate circulation, an area integral of vorticity, in the main pulmonary artery (MPA) as a new hemodynamic parameter for assessing patients with a repaired Tetralogy of Fallot (TOF).
The show that increased longitudinal circulation in the MPA, as measured by 4D-MR flow analysis, was shown to be independently associated with right ventricular dysfunction in patients with a repaired TOF.

Nanae Tsuchiya, Michinobu Nagao, Yumi Shiina, Shohei Miyazaki, Kei Inai, Sadayuki Murayama & Shuji Sakai , "Circulation derived from 4D flow MRI correlates with right ventricular dysfunction in patients with tetralogy of Fallot", Scientific Reports , Published Online (2021) .