Abstract 11991: Intraluminal and Intrawall Hyperintense Plaques Identified by Noncontrast T1-Weighted Magnetic Resonance Imaging Showed Different Vulnerable Plaque Morphology Assessed by Optical Coherence Tomography
Backgrounds: Many studies have suggested that the onset of clinical symptoms are related to thrombosis and intraplaque hemorrhage in patients with acute coronary syndrome. Recently, magnetic resonance T1-weighted imaging (T1WI) enables assessment of vulnerable morphology of carotid and coronary atherosclerotic plaques as hyperintense plaque (HIP). However, the association between localization of HIPs and plaque morphology was not investigated in previous studies. The aim of this study was to investigate the characteristics of coronary intraluminal or intrawall HIP on noncontrast T1WI compared with plaque morphology assessed by optical coherence tomography (OCT).
Methods and Results: A total of 80 lesions from 78 patients with either stable or unstable angina pectoris were included and divided into 3 groups according to the presence and the localization of HIPs. First, the plaques with the signal intensity of coronary plaque to cardiac muscle ratio (PMR) ≤1.0 were classified into non-HIPs (n=33). Then, HIPs with PMR >1.0 were classified into 2 types using the cross-sectional coronary images (Figure): intraluminal HIP was defined as one occupied the lumen and the lumen was not identified (n=19), and intrawall HIP was defined as one was localized within the coronary wall and the lumen was identified as black hole (n=28). Regarding plaque characterization detected by OCT, there were significant differences in the frequency of lipid rich plaque, calcification, thin-cap fibroatheroma, thrombus, macrophage infiltrations, and microchannels in the 3 groups. Multivariate analysis revealed that intrawall HIPs were related to macrophage infiltrations (P=0.006) and the absence of calcification (P=0.001). In contrary, intraluminal HIPs were associated with thrombus (P=0.005) and microchannels (P=0.007).
Conclusions: This study suggests that the intraluminal and intrawall HIPs on T1WI show different types of vulnerable plaque morphology assessed by OCT imaging.
- © 2013 by American Heart Association, Inc.