Emerging Technology: Hyperspectral Imaging

Abstract

Clinical decision-making in managing the patient with peripheral vascular disease is dependent upon patient history, physical examination, and noninvasive and invasive testing. Noninvasive testing currently includes the ankle-brachial index, pulse volume recordings, and transcutaneous oximetry. Each test yields information regarding perfusion and tissue oxygenation, but has limitations. The ankle-brachial index compares lower extremity blood pressure with the upper extremity, but it must be interpreted with caution in a patient with calcified atherosclerotic vessels, as is seen with diabetic patients, which can lead to an overestimation of actual pressure. Pulse volume recordings are mainly a qualitative estimation of distal perfusion and are highly dependent on the operator, which introduces both intraobserver and interobserver variability. Duplex ultrasound evaluation looses sensitivity in the small vessels of the limb and can be limited by instrument and operator. Transcutaneous oximetry is a quantitative measure of skin (end organ) oxygenation, but is limited by only evaluating one small area of the foot at a given time. Hyperspectral imaging was developed to possibly provide quantitative information regarding the spatial tissue oxygen saturation in patients with peripheral vascular disease.