Gadolinium-enhanced, vessel-tracking, two-dimensional coronary MR angiography: Single-dose arterial-phase vs. delayed-phase imaging

The purposes of our study were to investigate the benefits of using a singl e dose of an extracellular contrast agent for coronary magnetic resonance a ngiography (CMRA) and to determine the relative benefits of arterial-phase vs. delayed-phase image acquisition. The right coronary artery was imaged i n 10 healthy adults using a breath-hold, two-dimensional fast gradient echo pulse sequence designed for vessel tracking (multiphase, multislice image acquisition). Pre- and postcontrast CMRA was performed. Postcontrast Imagin g consisted of arterial- and delayed-phase CMRA following a 15 mL bolus (si ngle dose) of contrast media and of delayed-phase imaging following a cumul ative 45 mL contrast dose (triple dose). Contrast-enhanced CMRA provided a significantly higher (P < 0.001) signal-to-noise ratio (SNR) and contrast-t o-noise ratio (CNR) than noncontrast CMRA. CNR was highest for single-dose arterial-phase CAR;ZA (13.1 +/- 4.5) and triple-dose delayed-phase CMRA (13 .0 +/- 4.8), followed by single-dose delayed-phase CMRA (8.4 +/- 3.5) and n oncontrast CMRA (4.2 +/- 1.8). Single-dose arterial-phase CMRA provided the best visualization of the distal right coronary artery and was preferred f or blinded physician assessments. We concluded that utilization of a single dose of extracellular contrast media Improves CMRA, especially if timed fo r arterial-phase imaging. (C) 2001 Wiley-Liss, Inc.