Usefulness of Digital Infrared Thermal Imaging in Evaluating the Efficacy of Epidural Block among the Patients with Lumbar Radiculopathy

ABSTRACT

OBJECTIVE: To assess the clinical value of digital infrared thermal imaging (DITI) as an indicator for successful lumbar epidural block in patients with lumbar radiculopathy. METHOD: Ten patients having lumbar radiculopathy with low back pain and unilateral radicular leg pain participated in this study. The DITI was taken before and 20 minutes after lumbar epidural block. Visual analog scale (VAS) and straight leg raising (SLR) test were done before taking DITI. Temperatures were measured over 39 sectors of both lower extremities. Temperature differences of the affected and the sound side were compared between before and after lumbar epidural block. Correlation between the temperature differences and two variables, the VAS and SLR were assessed. RESULTS: There were the relative increase of temperature in DITI after lumbar epidural block, especially in posterior part of sector 7, posterior upper lateral thigh, sector 8, posterior upper middle thigh, sector 14, medial popliteal area, sector 15, posterior upper lateral calf, and sector 18, posterior middle medial calf. In posterior 15(th) sectors, the relative increase of temperature had a positive correlation with improvement of VAS score, and in 18(th) sector, it is positively correlated with improvement of SLR. CONCLUSION: It seems that the relative increase of temperature differences after lumbar epidural block is positively correlated with improvement of VAS and SLR in specific sectors, posterior 15(th) and 18(th) each. DITI may be useful as an objective indicator of successful lumbar epidural block.