Assessment of Microvascular Disease in the Diabetic Foot Using Spatial Frequency Domain Imaging

The following work explores the pathological implications of microvascular disease in the development of non-healing diabetic foot ulcers (DFU), and Spatial Frequency Domain Imaging (SFDI) ability to detect microvascular disease in the plantar aspect of the dermis of the feet. If not properly treated or monitored, DFUs can lead to adverse events such as amputation and lead to a lower quality of life. Historically, microvascular disease isn’t taken into consideration in terms of treating these patients. If there is concern for lack of blood supply to the lower extremities to aid in healing the DFU, the macrovascular blood supply is typically assessed; however, microvascular function is incredibly important for proper wound healing. Traditional non-invasive vascular assessments focus primarily on the overall macrovascular blood supply to the lower extremities, which leaves a clinical need to further define and understand the microvascular blood supply to the lower extremities. SFDI is a non-invasive imaging technology that uses LED illumination at multiple wavelengths within the visible light and near-infrared spectrum to illuminate the surface of the skin and interrogate tissue properties. SFDI measures the following: tissue oxygenation (StO2), concentration of hemoglobin within the capillary bed of the papillary dermis (HbT1), and concentration of hemoglobin within the capillary bed of the reticular dermis (HbT2). I hypothesize if a patient has microvascular disease present within the plantar aspect of the dermis of the feet, then SFDI technology can assess and quantify microvascular disease, which may lead to improved clinical decisions regarding a patient’s care