Multimodality Imaging of Plaque
MRI is non-destructive to tissue, does not expose subjects to ionizing radiation, and allows for high-resolution imaging of superficial arteries such as the carotid. MRI generates tissue contrast based on spatial variations in chemical composition, molecular motion, diffusion, physical state, and water content. It therefore provides better soft tissue discrimination than ultrasound- (US) and CT-based imaging. Previous studies, focusing on 2-D imaging and analysis of plaque structure in humans and animals, provide ex vivo and in vivo evidence that MR imaging of atherosclerosis can provide information on plaque composition as well as disease burden.
1. Ex vivo Comparison of Imaging Modalities:
Below we demonstrate comparisons of different ex vivo imaging modalities. These figures indicate that MRI has more details of the soft tissue plaque components, while the calcium content is well resolved in all modalities.
|MRI and Volume CT
MRI and US
|Results from 3D registration of T2-weighted MRI (column 1) with B-mode U/S (column 3) at three transverse locations (rows 1-3). The fused images are shown in column 2 with MR indicated in green and U/S overlaid in red. Arrows in row 2 indicate quality of calcium nodule alignment.
2. In Vivo Comparison of Imaging Modalities:
Clinical Pilot (non-Investigational Drug) CAPES: Protocol on the Progression of Atherosclerotic Plaques in High-Risk Patients with Established Carotid Artery Disease involving MRI and PET correlated with histological changes. Sponsored by Pharmacia, now part of Pfizer