Feasibility of k-t BLAST technique for measuring "seven-dimensional" fluid flow.
OBJECTIVE
To investigate the feasibility of rapid MR measurement of "seven-dimensional" (three velocity components, three dimensions, and time) fluid flow using the k-t Broad-use Linear Acquisition Speed-Up Technique (BLAST).


METHODS
Complete k-space data were acquired for pulsatile fluid flow in a model of a stenosed carotid bifurcation. The data was subsampled to simulate "training" and "accelerated acquisition" data for reconstruction using k-t BLAST.


RESULTS
Flow waveforms estimated from k-t BLAST reconstructions were in good agreement with those measured from the full data set for overall speedup factors up to approximately four times when slice-by-slice undersampling in k(y) was used. Accuracy was better than 25 mm/second or 7% (root-mean-square error) for individual time frames under these conditions. Flow patterns in the plane of symmetry, near the bifurcation, and in the stenosis were also in good agreement with those reconstructed from the full data set. Improved performance was obtained from undersampling in both k(y) and k(z), when acceleration factors up to 12 times gave acceptable results.


CONCLUSIONS
The k-t BLAST technique can be applied to flow quantification, and may make feasible the acquisition of time-resolved blood flow from extended arterial regions within acceptable examination times.
Marshall
Ian
I
Medical Physics and SHEFC Brain Imaging Research Centre for Scotland, University of Edinburgh, Edinburgh, UK. ian.marshall@ed.ac.uk
D001783:Blood Flow Velocity / Q000502:physiology*; D002346:Carotid Sinus; D016893:Carotid Stenosis / Q000175:diagnosis*; D005240:Feasibility Studies; D005583:Fourier Analysis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D011673:Pulsatile Flow; D012680:Sensitivity and Specificity