KEYHOLE METHOD FOR ACCELERATING IMAGING OF CONTRAST AGENT UPTAKE

Magnetic resonance (MR) imaging methods with good spatial and contrast resolution are often too slow to follow the uptake of contrast agents with the desired temporal resolution. Imaging can be accelerated by s kipping the acquisition of data normally taken with strong phase-encod ing gradients, restricting acquisition to weak-gradient data only. If the usual procedure of substituting zeros for the missing data is foll owed, blurring results. Substituting instead reference data taken befo re or well after contrast agent injection reduces this problem. Volunt eer and patient images obtained by using such reference data show that imaging can be usefully accelerated severalfold. Cortical and medulla ry regions of interest and whole kidney regions were studied, and both gradient- and spin-echo images are shown. The method is believed to b e compatible with other acceleration methods such as half-Fourier reco nstruction and reading of more than one line of k space per excitation .