Motivation: A bolus injection of the hyperpolarized pyruvate may affect heart rate, potentially causing a fixed trigger delay setup to miss signals from the targeted cardiac phase. Goal(s): To develop a retrospective compensation algorithm for dynamic cardiac 13C MRS by utilizing a phase-dependent simulation. Approach: Hemodynamic response of the heart to bolus injected pyruvate was simulated. The feasibility of the retrospective compensation method was tested using human cardiac data in vivo. Results: Time-resolved 13C MR spectroscopy, acquired from healthy subjects without a cardiac gating, could be properly assessed retrospectively using recorded heart rate and corresponding structural cine images Impact: By utilizing structural Cine images alongside heart rate records, a retrospectively reconstructing algorithm was developed for restoring the ideal input function despite the cardiac phases. This method enhanced the precision of cardiac MRS in HP MRI.
Lin et al. (Tue,) studied this question.