The Use of Medical Hyperspectral Technology to Evaluate Microcirculatory Changes in Diabetic Foot Ulcers and to Predict Clinical Outcomes

Abstract

OBJECTIVE -Foot ulceration is a serious complication of diabetes, and new techniques that can predict wound healing may prove very helpful. We tested the ability of medical hyperspectral technology (HT), a novel diagnostic scanning technique that can quantify tissue oxy-and deoxyhemoglobin to predict diabetic foot ulcer healing.RESEARCH DESIGN AND METHODS -Ten type 1 diabetic patients with 21 foot ulcer sites, 13 type 1 diabetic patients without ulcers, and 14 nondiabetic control subjects were seen up to 4 times over a 6-month period. HT measurements of oxyhemoglobin (HT-oxy) and deoxyhemoglobin (HT-deoxy) were performed at or near the ulcer area and on the upper and lower extremity distant from the ulcer. An HT healing index for each site was calculated from the HT-oxy and -deoxy values.RESULTS -Hyperspectral tissue oxygenation measurements observed changes in tissue immediately surrounding the ulcer when comparing ulcers that heal and ulcers that do not heal (P Ͻ 0.001). The sensitivity, specificity, and positive and negative predictive values of the HT index for predicting healing were 93, 86, 93, and 86%, respectively, when evaluated on images taken at the first visit. Changes in HT-oxy among the three risk groups were noted for the metatarsal area of the foot (P Ͻ 0.05) and the palm (P Ͻ 0.01). Changes in HT-deoxy and the HT healing index were noted for the palm only (P Ͻ 0.05 and P Ͻ 0.01, respectively).CONCLUSIONS -HT has the capability to identify microvascular abnormalities and tissue oxygenation in the diabetic foot and predict ulcer healing. HT can assist in the management of foot ulceration. Diabetes Care 30:903-910, 2007D iabetic foot ulceration (DFU) remains a serious problem, as 15% of all diabetic patients are expected to be affected with the complication during their lifespan (1). Infected and/or ischemic DFU accounts for ϳ25% of all hospital stays among diabetic patients, while foot ulceration precedes 85% of lowerextremity amputations (2). Currently, large multicenter studies (3-5) have reported that the healing rate of DFU over a 12-to 20-week period lies between 30 and 60%. Early identification of patients who will go on to fail to heal an ulcer can be of particular help, as it can allow the physician to make the right choice of treatment between a conservative and aggressive path. Pathways can be developed to streamline patient care and to apply new, expensive therapies only in patients who need them.The evaluation of neuropathy, peripheral vascular disease, presence of infection, and the depth of the ulcer are standard procedures for the management of DFU (6). However, none of the above measurements can predict wound healing. The only method that has previously been shown to predict wound healing is the measurement of changes in the ulcer area over a 4-week period of intensive care (7). However, the positive predictive value of this technique is only 58%, while the negative predictive value is 91%. Additionally, using the measurement-of-change method requires sequential patient examination...

Hypoxia inducible microRNA 210 attenuates keratinocyte proliferation and impairs closure in a murine model of ischemic wounds

“…S1C). Hyperspectral scanning technology has recently emerged as being productive in characterizing tissue ischemia by noninvasively monitoring the tissue oxyhemoglobin and deoxyhemoglobin ratio (8). This technology has enabled the detection of early changes in the skin microcirculation in patients (9).…”

Hyperspectral imaging and spectral-spatial classification for cancer detection

“…In medical applications, hyperspectral image data provide a powerful tool for noninvasive tissue analysis. Hyperspectral imaging has been used to provide quantitative data regarding tissue oxygen saturation in patients with peripheral vascular disease [3], to detect ischemic regions of the intestine during surgery [4], to predict and follow healing in foot ulcers of diabetic patients [5], and to diagnose hemorrhagic shock [6].…”

An intelligent telemedicine system for detection of diabetic foot complications

“…Several studies have been conducted to implement hyperspectral imaging for monitoring diabetic neuropathy [55], for monitoring and predicting ulcer healing process [56][57][58], and for assessing the risk for ulceration formation [59]. Beyond these three options for diabetic foot management, an intelligent monitoring system should also be capable of automatic recognition of ulcers and its pre-signs and to be able to discriminate these complications from the healthy skin.…”

“…It measures the spectral data of the entire target area. The measurements are rendered into image form, providing a non-contact and noninvasive diagnosis tool to monitor diabetic neuropathy [55], to assess the risk for ulceration formation [59], and to predict ulcer healing [56,57]. Most of the pioneer studies followed the 'analytical approach' [96], which seeks to deconstruct the reflectance spectra into biologically and physically meaningful factors, such as a map of tissue oxygenation.…”

“…Changes in the spectral information may happen ahead of presence of the diabetic foot complications. Previous studies [56,57,59] indicated that skin spectral information could be used to predict the wound development and healing. These study found that the changes in micro-and macro-circulation might happen days before the wound formation and healing.…”