Intraarterial gadolinium-enhanced 2D and 3D MR angiography: A preliminary study

PURPOSE: To evaluate, in phantom and canine models, intraarterial gadoliniu m-enhanced two-dimensional (2D) and three-dimensional (3D) magnetic resonan ce angiography (MRA). MATERIALS AND METHODS: The in vitro experiments examined gadodiamide soluti ons ranging in gadolinium (Gd) concentration from 0.1% to 100%. A spoiled g radient-recalled echo (SPGR) sequence was used with various repetition time /echo time (TR/TE) parameters. Signal was measured to determine which conce ntration yielded the highest signal. For in vivo experiments, pigtail cathe ters were placed in the abdominal aortae of two dogs. Intraarterial injecti ons of 20-30 mt of 0.5%-25% Gd solutions were performed. We acquired images with use of 2D and 3D SPGR techniques. Depiction of the abdominal aortae a nd renal vessels was assessed qualitatively and quantitatively. RESULTS: Phantom experiments demonstrated that a 2%-6% solution of Gd produ ced the highest MR signal, depending on the imaging parameters. In the cani ne model, a 2% Gd solution was best for 2D techniques, whereas 7%-14% Gd so lutions were optimal for 3D techniques. CONCLUSIONS: Intraarterial contrast material-enhanced 2D and 3D MRA can be successfully implemented with use of dilute Gd, Dilution permits the admini stration of more intraarterial injections per day, without exceeding the do se limit, compared with intravenous Gd-enhanced MRA. Intraarterial injectio ns also limit scan synchronization and contrast material dispersion issues. This technique may have application in MR-guided endovascular procedures.