Interventional catheter magnetic resonance angiography with a conventional 1.5-T magnet: work in progress

Magnetic resonance contrast enhancement depends on the relative timing of image acquisition. Limited human trials have demonstrated efficacy of intra-arterial gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in delineating vascular anatomy with X-rays. The present study assessed the ability of dynamic MR during intra-arterial Gd-DTPA administration to demonstrate vascular anatomy compared to conventional angiography as the gold standard. As interventional MR techniques using dedicated magnets proliferate, the ability to perform invasive MR angiography with a conventional magnet would be of great utility at established sites. Four subjects referred for different types of angiography underwent dynamic MR studies, including one with iliac artery stenting (Palmaz P204, Johnson and Johnson). All were examined with conventional angiography, and again after dynamic intra-arterial (IA) Gd-DTPA infusion. Coronal MRI images of the body were acquired using a 1.5-T superconducting magnet (three with a GE Signa, one with Philips NT), fast spoiled gradient echo (FSPGR); echo time (TE) = 4.2 msec, repetition time (TR) = 68-150 msec, flip = 75 degrees, 0-600 s after dilute Gd-DTPA IA bolus injection during sequential breath-hold acquisitions of 13-32 s each. All arteries were detected with dynamic MR. The FSPGR MRI with IA Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate arterial anatomy and arterial stent patency.