Background: Flow quantification is a central component in the evaluation of structural heart disease. Given the acoustic limitations of echocardiography, two-dimensional phase contrast magnetic resonance imaging (MRI) may be needed for non-invasive flow quantification. Careful evaluation of the dataset is necessary to ensure that the flow measurements are reliable.
Aim: The aim of this study was to use the conservation of mass principle to check the validity of the flow measurements.
Methods: Twenty consecutive patients referred cardiac MRI were included. Scans were acquired using a standard cardiac 1.5 Tesla MRI scanner. Phase-contrast MRI flow acquisition was planned in the proximal main pulmonary artery (MPA) and in the ascending aorta (Asc Ao).
Results: Net flow in the MPA was 75 ± 17 ml and net aortic flow was 74 ± 18 ml (P = 0.565). Bland-Altman analysis showed a mean difference between measurements of 1.45 ± 11.0 ml.
Conclusion: Applying the conservation of mass principle to check the internal validity of flow data is feasible and serves as a quality control measure for cardiac MRI.