Evaluation of atherosclerotic lesions using NMR microimaging

Magnetic resonance imaging (MRI) has been proposed as a potential tool in the evaluation of atherosclerotic lesions. However, two basic difficulties have to date prevented the full exploitation of the potentials of this technique: the poor spatial resolution of the conventional tomographs and the wide variety of the lesions as well as their intrinsic dishomogeneity. In this study the in vitro morphology of normal and atherosclerotic vascular tissue specimens has been evaluated using a high resolution spectometer equipped with a microimaging device. Morphological features of the vessel walls as small as 10(-1) mm have been detected and the distribution of lipids and of calcified or necrotic regions has been evidenced in atherosclerotic plaques. Different techniques, such as local spectroscopy performed on volumes of 1 mm3 and localized magnetization recovery measurements, have been employed to characterize specific regions of the vessel walls from the chemical and the physical point of view. The good agreement of NMR findings with histological data allows us to conclude that NMR microimaging represents a suitable technique for the in vitro detection and characterization of atheromatous lesions.