Molecular imaging of atherosclerosis using MRI

Invasive imaging techniques such as intravascular ultrasound show that the burden of atherosclerotic plaque disease in any given individual correlates with the likelihood of future cardiovascular events. MRI has the advantage of being non-invasive and, compared with other currently available molecular imaging modalities it has good spatial resolution, making it ideal for imaging the thin arterial wall. However, it has a lower sensitivity than positron emission tomography and optical imaging.

To try to overcome this limitation, the authors of this study designed a novel elastin-specific magnetic resonance contrast agent, to help to define the atherosclerotic plaque burden in an Apoe−/− mouse model. Elastin shows increased expression during plaque development and also has biological signalling functions. Furthermore, using magnetic resonance signal values the amount of elastin can be quantified.

After administration of the elastin-specific magnetic resonance contrast agent, the authors noted a gradual increase in MRI signal from plaque, which was diminished in those mice treated with pravastatin. This signal increased with time, and the authors correlated their MRI signal findings with immunoblotting and histology to confirm the amount of elastin present.