Assessment of cardiovascular disease using permeability rates: Quantification by optical coherence tomography

In order to prevent major damage to the cardiovascular system, it is of vital importance to monitor molecular changes in vascular tissues. Symptoms of cardiovascular diseases frequently do not manifest themselves until it is too late for effective treatment; therefore, methodologies that facilitate early detection are crucial. Atherosclerosis is a major underlying cause of many cardiovascular diseases; thus, elucidating the mechanisms of atherosclerosis is essential for shedding light on the initiation and progression of atherosclerotic lesions. Atherosclerosis includes an inflammatory process in arterial tissue that involves subintimal accumulation of lipoproteins particles, mainly low-density lipoprotein and lipoprotein[a]. Measurement of the permeation rates of these particles should extend our understanding of this disease and lead to methods for early disease detection. Over the past decade, optical coherence tomography (OCT) has become widely used in research and, more recently, has been used as a high-resolution imaging technique, capable of quantifying molecular permeability in biological tissues. OCT enables highly sensitive and accurate measurement of permeability rates of molecules and particles in vascular tissue. This sensitivity is due to high in-depth and transverse resolution along with a high dynamic range. In this chapter, we discuss the permeation of molecules and particles through human and animal vascular tissue.