Evaluation of skin using infrared thermal imaging for dermatology and aesthetic applications

Cutaneous Imaging Techniques

Cutaneous imaging is a central tenant to the practice of dermatology. In this article, the authors explore various noninvasive and invasive skin imaging techniques, as well as the latest deployment of these technologies in conjunction with the use artificial intelligence and machine learning. The authors also provide insight into the benefits, limitations, and challenges around integrating these technologies into dermatologic practice.

Diagnostic Infrared Thermography of the Tongue and Taste Perception in Patients with Oral Lichen Planus: Case-Control Study

Oral lichen planus (OLP) is a chronic inflammatory disease of autoimmune origin that affects the skin and mucous membranes. The aim of this study was to assess the effectiveness of infrared thermography (IRT) as a diagnostic tool in patients with oral lichen planus (OLP), as well as disturbances in taste perception, in cases with and without tongue involvement. A case-control study was carried out in a sample of 87 patients divided into three groups: healthy individuals (controls; n = 43), OLP patients without involvement of the tongue (n = 24), and OLP patients with involvement of the tongue (n = 20). The patient symptoms and the clinical characteristics of the lesions were assessed. Four thermal images of the tongue were obtained using IRT: dorsum, right and left lateral surface, and tip of the tongue. General taste perception capacity and subjective sweet, acid, salty, and bitter sensation were evaluated in all three groups. There were no statistically significant differences in the IRT values among the three groups (p ≥ 0.05). In the OLP patients with involvement of the tongue, significantly higher values were observed in the mixed forms of the disease (p = 0.032). The OLP patients with and without involvement of the tongue showed no significant alterations in taste sensation (p = 0.69). IRT may serve as a complementary tool for assessing the activity of OLP with involvement of the tongue. However, more research is needed in this field.

Use of Infrared Thermography in Medical Diagnosis, Screening, and Disease Monitoring: A Scoping Review

Thermography provides non-invasive, radiation-free diagnostic imaging. Despite the extensive literature on medical thermography, a comprehensive overview of current applications is lacking. Hence, the aim of this scoping review is to identify the medical applications of passive infrared thermography and to catalogue the technical and environmental modalities. The diagnostic performance of thermography and the existence of specific reference data are evaluated, and research gaps and future tasks identified. The entire review process followed the Joanna Briggs Institute (JBI) approach and the results are reported according to PRISMA-ScR guidelines. The scoping review protocol is registered at the Open Science Framework (OSF). PubMed, CENTRAL, Embase, Web of Science, OpenGrey, OSF, and PROSPERO were searched using pretested search strategies based on the Population, Concept, Context (PCC) approach. According to the eligibility criteria, references were screened by two researchers independently. Seventy-two research articles were identified describing screening, diagnostic, or monitoring studies investigating the potential of thermography in a total of 17,314 participants within 38 different health conditions across 13 therapeutic areas. The use of several camera models from various manufacturers is described. These and other facts and figures are compiled and presented in a detailed, descriptive tabular and visual format. Thermography offers promising diagnostic capabilities, alone or in addition to conventional methods.

Best Practices for Body Temperature Measurement with Infrared Thermography: External Factors Affecting Accuracy

Infrared thermographs (IRTs) are commonly used during disease pandemics to screen individuals with elevated body temperature (EBT). To address the limited research on external factors affecting IRT accuracy, we conducted benchtop measurements and computer simulations with two IRTs, with or without an external temperature reference source (ETRS) for temperature compensation. The combination of an IRT and an ETRS forms a screening thermograph (ST). We investigated the effects of viewing angle (θ, 0-75°), ETRS set temperature (TETRS, 30-40 °C), ambient temperature (Tatm, 18-32 °C), relative humidity (RH, 15-80%), and working distance (d, 0.4-2.8 m). We discovered that STs exhibited higher accuracy compared to IRTs alone. Across the tested ranges of Tatm and RH, both IRTs exhibited absolute measurement errors of less than 0.97 °C, while both STs maintained absolute measurement errors of less than 0.12 °C. The optimal TETRS for EBT detection was 36-37 °C. When θ was below 30°, the two STs underestimated calibration source (CS) temperature (TCS) of less than 0.05 °C. The computer simulations showed absolute temperature differences of up to 0.28 °C and 0.04 °C between estimated and theoretical temperatures for IRTs and STs, respectively, considering d of 0.2-3.0 m, Tatm of 15-35 °C, and RH of 5-95%. The results highlight the importance of precise calibration and environmental control for reliable temperature readings and suggest proper ranges for these factors, aiming to enhance current standard documents and best practice guidelines. These insights enhance our understanding of IRT performance and their sensitivity to various factors, thereby facilitating the development of best practices for accurate EBT measurement.