Cardiac MR flowmetry: Experimental validation and results in patients with operated cardiac deficiencies

Purpose: A flow-sensitive MR sequence (phase-contrast technique) was evaluated in phantom studies with regard to factors influencing measurements and correctness of results. The sequence was additionally used for functional evaluation of operated congenital heart disease. Methods: Pulsatile and constant flow were produced with the help of a phantom. Influence of angulation, range and vessel bending was evaluated. An examination protocol was developed from the results. 35 patients with surgically repaired congenital heart disease or without repair were examined. Results: A range preset below the actual flow velocity as well as angulation of more than 20 degrees were isolated as main pitfalls in MR flowmetry. In addition to morphological MR findings flow measurements were possible in 11 patients at vessel sites which were not or not completely suited for examination by Doppler ultrasound. Conclusion: The evaluated phase-contrast technique allows for fast and reliable flow quantification if the influences identified in phantom studies are considered.