Abstract #3644

Wu Y, Unal O, Korosec F, Wieben O, Wu Y, Du J, Peters D, Mistretta C

We applied the HighlY constrained back PRojection (HYPR) algorithm to the PR-TRICKs MRA technique. HYPR is a method that permits great improvements in temporal resolution in radial acquisitions by producing time frames using only a small subset of the total number of projections necessary to satisfy the Nyquist criterion. Streak artifacts that would ordinarily result from constructing images using a dramatically reduced number of projections are ameliorated by constraining the unfiltered back projected data to regions in which vessels are known to exist. In order to determine the location of the vessels, a vessel map is produced using data from multiple time frames. Because the data for each of the time frames is produced from projections that are acquired at slightly different angles, data from multiple time frames can be combined to produce high SNR, low artifact composite images (or vessel maps). Using the HYPR method, the temporal resolution can be improved by more than a factor of 80 as compared to a fu