Three-dimensional gadolinium-enhanced coronary magnetic resonance angiography: Initial experience

We present our initial experience on first-pass gadolinium-enhanced corolla ry artery magnetic resonance angiography (MRA). Three-dimensional segmented gradient-echo sequences were developed to image coronary arteries within a single breathhold during the injection of a double-dose contrast agent. Co mparisons were made between a short TR of 2.7-msec (n = 5) and a long TR of 5.0-msec (n = 3) sequences in terms of the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). An in-plane resolution of roughly I X I mm( 2) was achieved. Dramatic vascular signal enhancement by a factor of 3-5 wa s obtained in volunteers following the contrast agent injection, allowing f or clear visualization of proximal corollary arteries. The longer TR scans generally performed better in terms of SNR and CNR improvement (approximate ly 50%) but allowed for less covet-age. These preliminary results suggest t hat gadolinium-enhanced MRA is a useful tool to study proximal coronary art eries with breathhold, but for a larger coverage, a multiple close approach may be necessary.