k-t BLAST: Exploiting spatiotemporal structure in simultaneous cardiac and respiratory resolved volume imaging

A. Sigfridsson, J-P. E. Kvitting, L. Wigström, H. Knutsson Division of Clinical Physiology, Linköping University, Linköping, Sweden, Biomedical Engineering, Linköping University, Linköping, Sweden Introduction: The recently introduced k-t BLAST technique [1] for accelerating acquisition of dynamic imaging has shown promising results. By exploiting lower temporal frequency content in parts of the imaging region, and the ability to estimate this frequency content, aliasing resulting from undersampling the signal can to a significant extent be resolved. Imaging resolving both cardiac and respiratory phase simultaneously [2, 3] might also benefit from the k-t BLAST technique. Having two temporal dimensions increases the opportunities for exploiting the spatiotemporal structure. The acceleration of the acquisition can be useful to increase spatial or temporal resolution. The shortened scan time is especially beneficial for volumetric imaging, where traditional acquisitions are long (19 minutes [3]). It might also enable other sequences than the rapid SSFP sequence, such as phase contrast imaging. This is important for physiological studies, such as the study of respiratory effects on right ventricular filling. Simultaneous cardiac and respiratory phase resolution may also be beneficial for study and evaluation of respiratory artifact suppression schemes and with the use of accelerated imaging, essentially respiratory artifact free images may be obtained in a relatively short acquisition time.