Microvascular blood flow measurements with laser speckle contranst imaging in skin, lung and heart

Recently, a non–invasive method for measuring microvascular blood flow termed laser speckle contrast imaging (LSCI) has gained increasing attention. This methodology has previously been used to evaluate cutaneous blood flow in experimental settings and in the human brain. The LSCI method was first introduced in the 1980s and is a powerful tool for the full–field imaging of blood flow. In contrast to laser Doppler technologies, this method consists of assessing the blood flow response over a broad area of analysis rather than at a single point. This broad area of analysis is particularly important because it reduces the variability of the measurements due to the spatial heterogeneity of the skin microvasculature, especially in response to drug delivery. Indeed, previous studies have shown that the reproducibility of LSCI coupled with post–occlusive reactive hyperemia (PORH) and the iontophoresis of acetylcholine are very good.
Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function it is very limited used on the skin to assess cardiovascular diseases and furthermore it has never been used on lungs or heart before.
Objective (paradigm and hypothesis)
1. To determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with an increased risk for cardiovascular events (Framingham risk score more then 10) and if a daily intake of AGE for one year will show increased systemic microvascular functions.
2. To determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions in patients undergoing cardiopulmonary bypass surgery (CABG) before and after harvesting of v. saphenous magna.
3. To determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions in lungs connected to an Ex vivo lung perfusion (EVLP) circuit for evaluate lungs for lung transplantation.
4. To determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions in the heart