The questions are about the RV: how big (indexed volumes), how well it pumps, how much the pulmonary valve leaks (regurgitant fraction), and whether the outflow tract or branch pulmonary arteries are narrowed — because together they time pulmonary valve replacement.
Orient first
- Repair relieves RV outflow obstruction, often with a transannular patch, which leaves free pulmonary regurgitation; the RV dilates over decades.
- Pulmonary valve replacement is timed by RV volume thresholds, RV/LV function, exercise capacity and arrhythmia — verify the current thresholds (commonly RVEDVi around 150–160 mL/m²).
- Other late lesions: RVOT aneurysm, branch pulmonary artery stenosis, residual VSD, aortic root dilatation.
Acquire the study
- Short-axis cine stack (and axial stack for RV volumes), RVOT and branch PA cine; phase-contrast flow in the main PA, ascending aorta and each branch PA; MRA of the pulmonary arteries; LGE.
The manoeuvre
- RV and LV volumes indexed to BSA (EDVi, ESVi), EF — compare with the previous study, same contouring rules.
- Phase contrast in the main PA: forward and backward flow → pulmonary regurgitant fraction (%).
- RVOT: aneurysm or akinetic patch region; residual stenosis (velocity).
- Branch PAs: stenosis on MRA and flow split between left and right PA.
- Aortic root and ascending aorta diameters; residual VSD patch leak (Qp:Qs).
- LGE: RVOT patch and VSD patch expected; additional LV/RV LGE is a risk marker.
What confirms it
- Indexed RV volumes, biventricular EF, pulmonary regurgitant fraction and branch PA status stated and compared, so the team can apply its PVR thresholds.
What licenses you to exclude it
- Significant RV volume load is excluded by normal indexed RV volumes on a complete stack — trends matter more than one value.
The classic misread
- Changing contouring (trabeculae in vs out) between studies — creates a false interval change.