Contrast-enhanced MRI of carotid atherosclerosis: dependence on contrast agent.

PURPOSE: To investigate the dependence of contrast-enhanced magnetic resonance imaging (MRI) of carotid artery atherosclerotic plaque on the use of gadobenate dimeglumine versus gadodiamide.
MATERIALS AND METHODS: Fifteen subjects with carotid atherosclerotic plaque were imaged with 0.1 mmol/kg of each agent. For arteries with interpretable images, the areas of the lumen, wall, and necrotic core and overlying fibrous cap (when present) were measured, as were the percent enhancement and contrast-to-noise ratio (CNR). A kinetic model was applied to dynamic imaging results to determine the fractional plasma volume, v(p), and contrast agent transfer constant, K(trans).
RESULTS: For 12 subjects with interpretable images, the agent used did not significantly impact any area measurements or the presence or absence of necrotic core (P > 0.1 for all). However, the percent enhancement was greater for the fibrous cap (72% vs. 54%; P < 0.05) necrotic core (51% vs. 42%; P = 0.12), and lumen (42% vs. 63%; P < 0.05) when using gadobenate dimeglumine, although no apparent difference in CNR was found. Additionally, K(trans) was lower when using gadobenate dimeglumine (0.0846 min(-1) vs. 0.101 min(-1); P < 0.01), although v(p) showed no difference (9.5% vs. 10.1%; P = 0.39).
CONCLUSION: Plaque morphology measurements are similar with either contrast agent, but quantitative enhancement characteristics, such as percent enhancement and K(trans), differ. (c) 2009 Wiley-Liss, Inc.