Stanislas Rapacchi1, Pierre Croisille2, Magalie Viallon3, Denis Grenier1, Peter Kellman4, Han Wen4
1Creatis-LRMN, Universit Lyon 1, INSA Lyon, Lyon, France; 2Hopital Cardiologique et Pneumologique L. Pradel, Lyon, France; 3Hopital Cantonal Universitaire de Genve, Genve, Switzerland; 4National Heart, Lung and Blood Institute, NIH, Bethesda, MD, USA
Diffusion weighted imaging in the heart is greatly affected by contractile motion and remains challenging to date. Stimulated-echo approaches have relatively low signal level and require complete beat-to-beat positional repeatability which may not be met in patients. With spin-echo techniques, Gamper et al. recently proposed a robust motion-compensated sequence. However, through-slice diffusion was still difficult to measure. From their work, we developed an alternative approach for DWI, where a number of single-shot images of the same diffusion weighting are acquired at a series of different time points in diastole, and these are projected along the temporal axis by maximum-intensity-projection (tMIP) to form a true DWI. Through quantifying the motion-induced signal loss in DWI of a single slice based on experimental myocardial strain, we show the validity of tMIP and preliminary results in free-breathing scans of volunteers.
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