Photoacoustic Imaging for Diabetic Feet

Diabetic foot ulcers are a major complication of diabetes mellitus, high morbidity, mortality, and costs. Healing times of diabetic foot ulcers are longest when critical ischemia is present. Critical ischemia is diagnosed by using non-invasive assessment of blood flow in the feet, by means of the ankle pressure, toe pressure or transcutaneous oxygen measurements (tcpO2). Cut-off values for these measurements are given in the international guidelines, showing the probability of healing without vascular intervention. However, current non-invasive measurement systems have various disadvantages. Improving diagnostic assessment of the microcirculation of the diabetic foot is therefore needed. Photoacoustic Imaging (PAI) is a promising technique for the visualisation of blood in tissue. With PAI microcirculation in the outermost layers of the skin can be measured, and these measurements can be performed closer to the ulcer location. PAI is frequently used in assessment of microcirculation. However, it has never been applied to the diabetic foot. A pilot study applying PAI to the diabetic foot is therefore needed.

One measurement of approximately 60-90 minutes

Non-invasive blood pressure measurements will be performed and a total of four LSCI will be made. During the LSCI two occlusion tests will be performed to measure the microcirculation of the foot and stability of LSCI. There are no known risks associated with blood pressure measurements or LSCI, beside temporary discomfort.