Evaluation of hyperspectral imaging technology in patients with peripheral vascular disease

Hyperspectral imaging technology is a novel method of using transcutaneous measurement of oxyhemoglobin (HT-Oxy) and deoxyhemoglobin (HT-Deoxy) concentrations to create a two-dimensional, color-coded "oxygen map." The aims of this study were to compare the use of a hyperspectral imaging device with the transcutaneous oxygen measurement (TCOM), ankle-brachial index (ABI), and severity of peripheral vascular disease (PVD) and to assess their correlations.

This prospective study recruited 294 participants divided into three distinct groups composed of healthy volunteers and patients with PVD. Patients underwent measurements of lower limbs at a standardized point over the head of the first metatarsal on the plantar aspect using the hyperspectral imaging device, generating four outputs including HT-Oxy, HT-Deoxy, oxygen saturation (HT-Sat), and skin temperature, and the TCOM system, generating transcutaneous partial pressure of oxygen (TcpO₂) and carbon dioxide (TcpCO₂). Demographic data, severity of PVD, ABI, and other pertinent information were obtained from both the participants and medical records.

Interoperator reliability ranged from 86% to 94% across the four hyperspectral imaging device outputs, whereas intraoperator reliability ranged from 92% to 94%. The HT-Oxy, HT-Sat, TcpCO₂, and ABI of the diseased limb correlated significantly with the severity of PVD. HT-Sat significantly correlated with TcpO₂ (R = 0.19), TcpCO₂ (R = -0.26), ABI (R = 0.42), and skin temperature (R = 0.56). HT-Deoxy also correlated with TcpCO₂ (R = 0.27).

This study demonstrates the reliability of hyperspectral imaging in comparison to TCOM, ABI, skin temperature, and severity of PVD in a series of patients. Its correlation to other established modalities and low interoperator and intraoperator variability could enable this modality to be a useful screening tool in PVD.