Two- and Three-dimensional MR Coronary Angiography with Intraarterial Injections of Contrast Agent in Dogs: A Feasibility Study

Abstract

Magnetic resonance (MR) images of coronary arteries were acquired with an inversion recovery-prepared technique after intraarterial injection of contrast material in five dogs. Real-time two-dimensional projection images were obtained with a temporal resolution of 3 frames per second. Three-dimensional electrocardiographically triggered high-spatial-resolution images were obtained with a fraction of the contrast agent required for intravenous injections. Background tissues were adequately suppressed in all images. On the basis of this experimental data, the optimal contrast agent concentration for two-dimensional real-time projection imaging was 6%. This preliminary work shows that contrast material-enhanced MR angiography with intraarterial injections is feasible with the proposed techniques.

Comparison between intravenous and intraarterial contrast injections for dynamic 3D MRI of liver tumors in the VX2 rabbit model

“…The TI was defined as the time interval between the application of the global inversion preparation pulse and the sampling of the first phase-encode line of the centrically ordered acquisition. The TI and sequence flip angle were optimized to null signals from background tissues over a wide range of T1 relaxation times in order to maximize the conspicuity of those tissues with T1 significantly shortened by the presence of Gd contrast agent (T1 shortened to Ͻ100 msec) (20,21). The TI and flip angle were optimized to ideally suppress all tissues that did not contain Gd contrast agent.…”

Feasibility of MR-guided Angioplasty of Femoral Artery Stenoses Using Real-time Imaging and Intraarterial Contrast-enhanced MR Angiography

“…Omary and Green [7] showed the feasibility of intraarterial angiography of coronary arteries in dogs. The accuracy between intravenous and intraarterial MRA was not different [8]. Until now, no experience existed with intraarterial MRA in humans.…”

Catheter contrast-enhanced coronary CT-angiography using an aortic root injection- preliminary technical development in four patients

“…Intra-arterial catheter directed injections of MR contrast [11][12][13][14][15][16] in animal models can depict the coronary arteries and regional myocardial perfusion [22]. Similar studies with CTA, however, have not been performed.…”

“…Recently, catheter directed intra-arterial (IA) enhanced MRA of the coronary arteries has been performed in animal models [11][12][13][14][15][16]. Advantages include elimination of bolus arrival timing issues, no systemic contrast dilution and assessment of the functional significance of coronary stenosis with myocardial first pass perfusion (FPP).…”