Analysis of aortic blood-flow from ECG-free realtime PC MRI

Background Realtime PC MRI flow image data is usually acquired in combination with ECG signal acquisition, which enables the separation of the image sequences into cardiac cycles. Thereby, it becomes possible to analyze the variation of bloodflow-related parameters through influences such as arrhythmia or breathing maneuvers. Because of the time consuming ECG lead positioning and the errors occurring through interferences with MRI gradients, it is desirable to be able to do the cycle separation without the ECG signal for sequences which do not require ECG triggering. Our approach for an ECG-free multicycle flow analysis is based on the image data only. In order to compare the image-based cycle separation with the ECG-based approach, the suggested method has been applied to data acquired with ECG-signal, and the differences in cycle separation as well as their influence on the clinically relevant parameters have been analyzed.