Temporal frequency analysis of dynamic MRI techniques

Dynamic imaging strategies often involve updating certain areas of k-space (i.e., the low spatial frequencies) more frequently than others. However, i mportant dynamic signal changes may occur anywhere in k-space, In this stud y, a dynamic k-space sampling analysis method was developed to determine th e energy error associated with specific dynamic sampling strategies. The me thod uses the temporal power spectrum of k-space signals to determine the l evel and k-space locations of sampling errors. The proposed method was used to compare two dynamic sampling strategies (full sequential and keyhole) f or a dynamic first-pass bolus simulation and a continuous heart imaging stu dy, The error analysis agreed well with the errors in the reconstructed ima ges. The technique can be used to determine the minimum sampling frequency for any location in the k-space, and may ultimately be used to optimize dyn amic sampling strategies. Magn Reson Med 45:550-556, 2001, (C) 2001 Wiley-L iss, Inc.