Dynamic Contrast-enhanced Myocardial Perfusion MRI Accelerated with K-t Sense

In the k-t sensitivity encoding (k-t SENSE) method spatiotemporal data correlations are exploited to accelerate data acquisition in dynamic MRI studies. The present study demonstrates the feasibility of applying k-t SENSE to contrast-enhanced myocardial perfusion MRI and using the speed-up to increase spatial resolution. At a net acceleration factor of 3.9 (k-t factor of 5 with 11 training profiles) accurate representations of dynamic signal intensity (SI) changes were achieved in computer simulations. In vivo, 5x k-t SENSE was compared with 2x SENSE (identical acquisition parameters except for in-plane spatial resolution = 1.48 x 1.48 mm(2) vs. 2.64 x 2.64 mm(2), respectively). In 10 volunteers no differences in myocardial SI profiles were found (relative peak enhancement = 151% vs. 149.7%, maximal upslope = 12.9%/s vs. 13.3%/s for 2x SENSE and 5x k-t SENSE, respectively, all P > 0.05). Overall image quality was similar, but endocardial dark rim artifacts were reduced with k-t SENSE. Signal-to-noise ratio (SNR) in the myocardium was greater with 5x k-t SENSE by a factor of 1.36 +/- 0.23 at peak contrast enhancement with the relative yield decreasing with increasing dynamics in the object in accordance to theory. Higher nominal acceleration factors of up to 10-fold were shown to be feasible in computer simulations and in vivo.