CARDIAC MAGNETIC-RESONANCE FLUOROSCOPY

A technique is described for high speed interactive imaging of the hea rt with either white or black blood contrast. Thirty-two views of a se gmented, magnetization-prepared gradient echo sequence are acquired du ring diastole. Using three-quarter partial Fourier sampling, data for a complete 128 x 128 image are acquired in three cardiac cycles. High speed reconstruction provides an image update of each cardiac cycle 15 9 ms after measurement. An independent graphical user interface facili tates interactive control of section localization and contrast by perm itting pulse sequence parameter modification during scanning. The effi ciency and image quality of the cardiac MR fluoroscopy technique were evaluated in 11 subjects. Compared with the conventional graphic presc ription method, the cardiac fluoroscopy technique provides an approxim ate eightfold reduction in the time required to obtain subject-specifi c double oblique sections. Image quality for these scout acquisitions performed during free breathing was sufficient to identify small cardi ac structures.