Detection of coronary plaques using MR coronary vessel wall imaging: validation of findings with intravascular ultrasound

OBJECTIVES: Compared with X-ray coronary angiography (CAG), magnetic resonance imaging of the coronary vessel wall (MR-CVW) may provide more information about plaque burden and coronary remodelling. We compared MR-CVW with intravascular ultrasound (IVUS), the standard of reference for coronary vessel wall imaging, with regard to plaque detection and wall thickness measurements. METHODS: In this study 17 patients with chest pain, who had been referred for CAG, were included. Patients underwent IVUS and MR-CVW imaging of the right coronary artery (RCA). Subsequently, the coronary vessel wall was analysed for the presence and location of coronary plaques. RESULTS: Fifty-two matching RCA regions of interest were available for comparison. There was good agreement between IVUS and MR-CVW for qualitative assessment of presence of disease, with a sensitivity of 94% and specificity of 76%. Wall thickness measurements demonstrated a significant difference between mean wall thickness on IVUS and MR-CVW (0.48 vs 1.24 mm, P < 0.001), but great heterogeneity between wall thickness measurements, resulting in a low correlation between IVUS and MR-CVW. CONCLUSIONS: MR-CVW has high sensitivity for the detection of coronary vessel wall thickening in the RCA compared with IVUS. However, the use of MRI for accurate absolute wall thickness measurements is not supported when a longitudinal acquisition orientation is used. KEY POINTS : * Both MRI and IVUS can assess coronary vessels * Both MRI and IVUS can identify coronary vessel wall thickening. * MRI provides more information about the coronary plaque burden than conventional angiography. * However, MRI overestimates absolute coronary wall thickness when compared with IVUS.