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

Abstract

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.

Coronary Wall Imaging with MRI

“…Rapid technological advances in the development of open and real-time MR scanners with an array of MR compatible monitoring equipment and surgical instrumentation [41] offers the promise of MR-guided coronary intervention as already reported for peripheral vascular [42,43] and neurosurgical intervention [44].…”

Interventional and intraoperative MR: review and update of techniques and clinical experience

“…Moreover, time-resolved MRA can be gained by a reduced amount of contrast agent. The technique was demonstrated both in vitro in flow phantoms and in vivo in animal models [89,92] and humans [93,94] (Fig. 9).…”

Endovascular interventional magnetic resonance imaging

“…The feasibility of the proposed technique was shown both in vitro in flow phantom studies as well as in vivo in animal models and human patients. Successful studies were performed in hemodialysis access grafts in the forearm (Bos et al 2001), in iliac arteries of humans (Tello et al 1999) and animals (Bos et al 2000) (see figure 8), in the aorta (rabbits) and coronary arteries (dogs) (Serfaty et al 2000), in the renal arteries (pigs) (Omary et al 2002b) and in various other abdominal vessels such as the superior mesenteric artery and the hepatic artery (Quick et al 2003). Selective MRA may prove to be an important tool for use during MR-guided endovascular interventions.…”