Purpose: To evaluate the MR agreement of cardiac function parameters between volumetric (cine SSFP) and phase contrast flow (PC-flow) assessment in patients with repaired tetralogy of Fallot (r-TOF) and chronic pulmonary regurgitation (PR) at rest and under dobutamine stress (DS-MR). Materials and Methods: We studied 18 patients with r-TOF and severe chronic PR (34 ± 12.7 years, PR fraction[flow] 44 ± 15%) by cardiac MR at rest, 10 and 20 μg/kg/min of dobutamine. We compared analogous functional parameters by volumetry and PC-flow: (i) Systemic output [left ventricle stroke volume (LVSV) versus aortic forward flow (AOFF)], (ii) Pulmonary output [right ventricle stroke volume (RVSV) versus pulmonary forward flow (PAFF)], (iii) PR volume [(RV SV-LVSV) versus pulmonary backward flow (PA BF)], (iv) PR fraction [(RVSV-LVSV/RV SV) versus (PABF/PAFF)]. Results: We found excellent Bland-Altman agreement (mean difference ± limits of agreement, mL/beat/m2) at rest for both the systemic (-0.8 ± 5.7) and pulmonary strokes volumes (-0.1 ± 7.6), which slightly deteriorates during DS-MR. The PR volume showed acceptable agreement at rest (-3.6 ± 15.1), but also further deteriorated during stress (5.4 ± 24). In contrast, the PR fraction showed poor agreement equally at rest (-5.6 ± 22.8) and DS-MR (3.2 ± 19.2). Conclusion: In r-TOF with chronic PR, analogous functional parameters should not be used interchangeably between volumetric and PC-flow assessment during DS-MR evaluation.
- blood flow
- cardiac volume
- tetralogy of Fallot
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging