A retrospective study of 120 repaired tetralogy-of-Fallot patients found similar conventional CMR, pulmonary regurgitation, and clinical outcomes across tubular and pyramidal RVOT shapes, while 4D-flow CMR detected local differences in velocity, wall shear stress, and energy loss. This shows imaging sensitivity, not yet prognostic or transcatheter-valve selection utility.
Key findings
- The groups did not differ in demographics, transannular patch history, long-term events, ventricular volumes/function, or pulmonary-regurgitation severity. Tubular RVOTs had higher peak velocity at the RVOT but lower at the right pulmonary artery, higher maximum WSS at the RVOT, pulmonary valve, and main pulmonary artery, and greater average energy loss at the pulmonary valve.
Why this matters globally
4D-flow may enable hemodynamic phenotyping before valve surveillance or intervention planning, but reproducible thresholds and incremental prognostic value over conventional CMR are required.
Thai researcher contribution
Siriraj pediatric cardiology, cardiac-center, and radiology teams assembled a substantial Thai rTOF series and applied 4D-flow to postoperative anatomy.
Limitations to consider
This retrospective single-center study had sparse minor morphologies and a main comparison of 108 patients, with selection and multiplicity concerns. Classification reproducibility and clinically meaningful 4D-flow thresholds are not reported. Similar clinical outcomes preclude claims about risk or PPVI suitability.