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

We present our initial experience on first-pass gadolinium-enhanced coronary 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. Comparisons 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 1 x 1 mm2 was achieved. Dramatic vascular signal enhancement by a factor of 3-5 was obtained in volunteers following the contrast agent injection, allowing for clear visualization of proximal coronary arteries. The longer TR scans generally performed better in terms of SNR and CNR improvement (approximately 50%) but allowed for less coverage. These preliminary results suggest that gadolinium-enhanced MRA is a useful tool to study proximal coronary arteries with breathhold, but for a larger coverage, a multiple dose approach may be necessary.