MULTISLICE FIRST-PASS MYOCARDIAL PERFUSION IMAGING ON A CONVENTIONAL CLINICAL SCANNER

A technique is demonstrated for the acquisition and processing of mult islice, first-pass contrast-enhanced perfusion images in the myocardiu m. The acquisition is a modification of ''keyhole'' imaging in which t ime series images are acquired by sampling a limited segment of k-spac e, corresponding to the low spatial frequencies. In the modification d emonstrated here, keyhole samples are divided into two groups that are sampled on alternate cardiac cycles. The alternate ''missing'' k-spac e portions are synthesized by Fourier interpolation. Visualization of contrast agent accumulation by image subtraction is demonstrated. A mo tion artifact reduction process using time domain Fourier filtering is used to reduce artifacts from respiration. Studies were performed on 46 patients at 1.5 T using gadoteridol (0.05-0.1 mmol/kg) injected int o the right antecubital vein in conjunction with radionuclide imaging. Fully concordant studies were noted in 27 of these patients. Remainin g studies were either partially or completely discordant for reasons r elating to the differing natures of radionuclide versus MR contrast ag ent characteristics.