Focus Session 6: MR Techniques and Methods: Non-Contrast CMR and New Contrast Mechanisms (2019)-Heartbeat-to-Heartbeat Quantitative Cardiac BOLD Imaging during a Single Breath-Hold using a combined Gradient Echo-Spin Echo EPI sequence

Heartbeat-to-Heartbeat Quantitative Cardiac BOLD Imaging during a Single Breath-Hold using a combined Gradient Echo-Spin Echo EPI sequence

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Video Transcription

Video Summary

The speaker describes a five-echo gradient/spin-echo EPI method that enables heartbeat-by-heartbeat T2 and T2* mapping. Breath-hold-induced CO2 changes cause vasodilation, increasing signal intensity, T2, and T2* values. Although the signal is influenced by RR interval changes and other physiological effects, the multiparametric fit separates these better than raw intensity. The method correlates well with standard mapping, shows significant slopes during breath holds, and is reproducible on rescan. Limitations include low voxel resolution and EPI-related artifacts in the lateral wall. Future improvements may include fingerprinting, hyperventilation protocols, and alternative readouts.

Keywords

five-echo EPI

T2 mapping

T2* mapping

breath-hold CO2

myocardial vasodilation