MOLECULAR FLUORESCENCE IMAGING/CARDIOLOGY: Near-infrared fluorescence facilitates in-vivo imaging of atherosclerosis

Molecular imaging has become an important clinical and research tool for the study of heart disease, allowing in-vivo visualization of inflammation and other biological processes. But while the standard approaches—MRI and PET—can image biological aspects of large vessels, these methods do not allow imaging of coronary arteries. A recent paper describes how high-resolution optical imaging modalities—for instance, near-infrared fluorescence (NIRF) coupled with fluorescent probes—have enhanced sensitivity and facilitated development of new intravascular imaging options.¹

According to the authors, NIR light has many advantages for biomedical applications: Unlike visible light, it penetrates deeply into tissue. It is also less affected by photon absorbers such as hemoglobin, lipid, and water within tissue and, thanks to less autofluorescence in the NIR window, enables high target-to-background ratios. In fact, imaging within the NIR range can substantially improve the potential for in-vivo work.

NIRF molecular imaging uses 650–900 nm bandwidth light to excite an optical contrast agent or probe, which emits NIR fluorescence detectable using an appropriate emission filter and a high sensitivity charge-coupled camera. The paper describes in-vivo molecular imaging of atherosclerosis using a catheter-based, 2-D NIRF approach as a promising tool for detection of vascular inflammation. The platform can be paired with existing clinical imaging technologies such as angiography and intravascular ultrasound (IVUS) to provide a unique and novel integrated multimodal molecular imaging technique that distinguishes inflammatory atheromata, and allows detection of intravascular NIRF signals in human-sized coronary arteries.

1. M.A. Calfon et al., J. Vis Exp., 4, 54, 2257 (2011).

More BioOptics World Current Issue Articles
More BioOptics World Archives Issue Articles