Pulmonary MR angiography with contrast agent at 4 Tesla: A preliminary result

In this study, pulmonary MR angiography (MRA) using a tailored coil at 4 Te sla in conjunction with an intravenous injection of contrast agent is descr ibed. Three-dimensional gradient-echo images were obtained during the intra venous injection of 0.05, 0.1, and 0.2 mmol/kg body weight of gadodiamide t o investigate the signal enhancement effect of the contrast agent in pulmon ary arteries qualitatively and quantitatively. In the qualitative analysis, the subsegmental branches were visualized on every dose. In the quantitati ve analysis, the average contrast-to-noise ratios (CNRs) of the main pulmon ary arteries increased in a dose-dependent manner. However, the CNRs of seg mental arteries did not increase as the dose of contrast agent increased, a s observed at 1.5 Tesla MRI. These observations demonstrate the feasibility of delineating the pulmonary vasculature using a contrast agent; however, our results also suggest possible high-field-related disabilities that need to be overcome before high-field (greater than or equal to4 Tesla) MRI can be used to full advantage. (C) Wiley-Liss, Inc.