REAL-TIME INTERACTIVE MRI ON A CONVENTIONAL SCANNER

A real-time interactive MRI system capable of localizing coronary arte ries and imaging arrhythmic hearts in real-time is described. Non-2DFT acquisition strategies such as spiral-interleaf, spiral-ring, and cir cular echo-planar imaging provide short scan times on a conventional s canner. Real-time gridding reconstruction at 8-20 images/s is achieved by distributing the reconstruction on general-purpose UNIX workstatio ns. An X-windows application provides interactive control. A six-inter leaf spiral sequence is used for cardiac imaging and can acquire six i mages/s. A sliding window reconstruction achieves display rates of 16- 20 images/s. This allows cardiac images to be acquired in real-time, w ith minimal motion and flow artifacts, and without breath holding or c ardiac gating. Abdominal images are acquired at over 2.5 images/s with spiral-ring or circular echo-planar sequences. Reconstruction rates a re 8-10 images/s. Rapid localization in the abdomen is demonstrated wi th the spiral-ring acquisition, whereas peristaltic motion in the smal l bowel is well visualized using the circular echo-planar sequence.