Infantile hemangioma status by dynamic infrared thermography: A preliminary study

Beyond visual inspection: The value of infrared thermography in skin diseases, a scoping review

Although warmth is a key sign of inflammatory skin lesions, an objective assessment and follow-up of the temperature changes are rarely done in dermatology. The recent availability of accurate, sensitive and cost-effective thermography devices has made the implementation of thermography in clinical settings feasible. The aim of this scoping review is to summarize the evidence around the value and pitfalls of infrared thermography (IRT) when used in the dermatology clinic. A systematic literature search was done for original articles using IRT in skin disorders. The results concerning the potential of IRT for diagnosis, severity staging and monitoring of skin diseases were collected. The data on the sensitivity and specificity of IRT were extracted. Numerous studies have investigated IRT in various skin diseases, revealing its significant value in wound management, skin infections (e.g. cellulitis), vascular abnormalities and deep skin inflammation (e.g. hidradenitis suppurativa). For other dermatological applications such as the interpretation of intradermal and patch allergy testing, hyper-/anhidrosis, erythromelalgia, cold urticaria and lymph node metastases more complex calculations, provocation tests or active cooling procedures are required. Dermatologists should be aware of a learning curve of IRT and recognize factors contributing to false positive and false negative results. Nonetheless, enough evidence is available to recommend IRT as a supplement to the clinical evaluation for the diagnosis, severity and follow-up of several skin diseases.

OUP accepted manuscript

Infrared thermography is a useful adjunct for the clinical monitoring of infantile hemangioma (IH) activity with or without treatment. There is a dearth or reporting on the ideal tissue for standardizing temperature readings from IH. This case illustrates the use of mean medial canthal temperatures and the differential hemangioma temperatures for monitoring of facial IH.

Effect of fatigue strength exercise on anterior thigh skin temperature rewarming after cold stress test

Although dynamic thermography skin temperature assessment has been used in medical field, scientific evidence in sports is scarce. The aim of the study was to assess changes in anterior thigh skin temperature in response to a cold stress test after a strength exercise fatiguing protocol. Ten physically active adults performed a familiarization session and two strength exercise sessions, one with dominant and the other with non-dominant lower limb. Participants performed bouts of 10 concentric and eccentric contractions of leg extensions in an isokinetic device until reaching around 30% of force loss. Infrared thermographic images were taken at baseline conditions and after the fatigue level from both thighs after being cooled using a cryotherapy system. ROIs included vastus medialis, rectus femoris, adductor and vastus lateralis. Skin temperature rewarming was assessed during 180s after the cooling process obtaining the coefficients of the following equation: ΔSkin temperature = β₀ + β_{1 *} ln(T), being β₀ and β₁ the constant and slope coefficients, respectively, T the time elapsed following the cold stress in seconds, and ΔSkin temperature the difference between the skin temperature at T respect and the pre-cooling moment. Lower β₀ and higher β₁ were found for vastus lateralis and rectus femoris in the intervention lower limb compared with baseline conditions (p < 0.05 and ES > 0.6). Adductor only showed differences in β₀ (p = 0.01 and ES = 0.92). The regressions models obtained showed that β₀ and β₁ had a direct relationship with age and muscle mass, but an inverse relationship with the number of series performed until 30% of fatigue (R² = 0.8). In conclusion, fatigue strength exercise results in a lower skin temperature and a faster thermal increase after a cold stress test.

Reproducibility of Skin Temperature Response after Cold Stress Test Using the Game Ready System: Preliminary Study

The objective of this preliminary study was to determine the reproducibility of lower limbs skin temperature after cold stress test using the Game Ready system. Skin temperature of fourteen participants was measured before and after cold stress test using the Game Ready system and it was repeated the protocol in four times: at 9:00, at 11:00, at 19:00, and at 9:00 h of the posterior day. To assess skin temperature recovery after cold stress test, a logarithmic equation for each region was calculated, and constant (β₀) and slope (β₁) coefficients were obtained. Intraclass correlation coefficient (ICC), standard error (SE), and within-subject coefficient of variation (CV) were determined. No differences were observed between measurement times in any of the regions for the logarithmic coefficients (p > 0.38). Anterior thigh (β₀ ICC 0.33–0.47; β₁ ICC 0.31–0.43) and posterior knee (β₀ ICC 0.42–0.58; β₁ ICC 0.28–0.57) were the regions with the lower ICCs, and the other regions presented values with a fair and good reproducibility (ICC > 0.41). Posterior leg was the region with the better reproducibility (β₀ ICC 0.68–0.78; β₁ ICC 0.59–0.74; SE 3–4%; within-subject CV 7–12%). In conclusion, cold stress test using Game Ready system showed a fair and good reproducibility, especially when the posterior leg was the region assessed.

Colorimetric analysis of images in the follow-up of infantile hemangiomas

BACKGROUND/OBJECTIVES

Infantile hemangiomas (IH) are common vascular tumors that appear early in life, have a rapid proliferative phase and slowly involute. There are no standardized ways to evaluate the regression of these lesions. We propose a colorimetric analysis of photographs to allow a more precise determination of IH treatment response and involution.

METHODS

Patients 1-10 months of age with superficial or mixed IH were included. The lesions were managed with 0.5% topical timolol ophthalmic solution. Patients were followed for 16 weeks with 6 evaluations each. Photographic images were taken with a red and green circle placed beside each hemangioma. The photographs were treated as to equalize the size, color, and brightness among them based on the colors of the two circles. A grading scale was established based on the color of the patient skin (0) and the color of the hemangioma at the beginning of treatment (100) by pixel analysis using Adobe Photoshop® software.

RESULTS

A total of 17 patients 1 to 10 months of age were included, of whom 16 were girls (94%). Fourteen lesions were superficial, and 3 were mixed IH. The median time prior to initiation of treatment was 105 days (44-232). All lesions showed some degree of clearing. The mean of lightening of color intensity observed was of 45% (17%-74%) over the period of follow-up.

CONCLUSIONS

The colorimetric analysis of the digital images allowed an accurate and objective evaluation of IH clearing.

Comparison between near-infrared fluorescence imaging with indocyanine green and infrared imaging: on-bench trial for kidney perfusion analysis. A project of the ESUT-YAUWP group

BACKGROUND

Infrared thermography (IRT) imaging technology is able to measure surface temperatures in real-time. The aim of our study is to understand whether IRT imaging is a reliable technology for the assessment of kidney-parenchyma perfusion with warm fluids.

METHODS

We used three porcine kidneys as a sample. IRT was compared to Near-infrared fluorescence (NIRF) technology with Indocyanine Green (ICG), X-rays with Contrast medium was used as a benchmark. Each kidney, placed inside an incubator, was perfused with contrast medium by a vascular 6-Fr catheter, to preview the perfusable parenchymal area. 100 mL of saline solution at 45 °C was then administered along a five-minutes time, followed by a second administration of 2/10 diluted ICG solution. A FLIR© C2 IR camera was used to acquire thermal data. During ICG administration, image acquisition was obtained with FireFly technology, with a 0° endoscopic camera. Quantitative variables are described using median and quartiles.

RESULTS

Real-time evaluation by IRT showed that, after five minutes of perfusion, it was possible to highlight the same parenchymal areas as visualized by X-ray. The IR images showed that surface temperature rise was directly reflecting local perfusion with heated saline solution. Analysis of NIRF technology and ICG showed an overlap between the two technologies. In addition to the compared technology, IR provided separate temperature measurement for each pixel in real time. Our findings were replicable on all the three kidneys examined. Higher resolution IR-cameras could provide even more detailed information.

CONCLUSIONS

Although NIRF technology with ICG is providing more image detail, we demonstrated that IRT is capable of detecting kidney parenchyma perfusion with warm fluids. Further studies will show its feasibility in graft re-perfusion assessment during kidney transplant or similar applications.

Heat transfer analysis and resolution quantification of active dynamic thermography through human skin

OBJECTIVES

Active dynamic thermography (ADT) is a non-contact imaging technique that characterizes non-homogeneities in thermal conductance through objects as a response to applied energy stimulus. The aim of this study was to (i) develop a heat transfer model to define the relationship between thermal stimulation and resolution and (ii) empirically quantify the resolution an ADT imaging system can detect through a range of depths of human skin.

MATERIALS AND METHODS

A heat transfer model was developed to describe a thermally non-conductive object below a sheet of skin. The size and depth of the object were varied to simulate wound conditions, while the intensity and duration of thermal stimulation were varied to define stimulation parameters. The model was solved by numerical analysis. For ex vivo experimentation, freshly excised human pannus tissue was cut into sheets of thickness 2.54-6.35 × 10-4  m (0.010-0.025vinches) for a total of 48 grafts from 12 patients. Grafts were placed over a 3D printed resolution target with objects ranging from 0.445-0.125 LP/mm. Stimulation from a 300 W halogen lamp array was applied for 0.5-14 seconds for a total of 480 experiments.

RESULTS

ADT resolved a peak of 0.428 ± 0.025 LP/mm for 2.54 × 10-4  m (0.010 inches) skin thickness, 0.384 ± 0.030 LP/mm for 3.81 × 10-4  m (0.015 inches), 0.325 ± 0.042 LP/mm for 5.08 × 10-4  m (0.020 inches) and 0.249 ± 0.057 LP/mm for 6.35 × 10-4  m (0.025 inches) skin thickness. Additionally, it was determined that the ideal duration of stimulation energy with a 300 W stimulation system was 4 seconds for 2.54 × 10-4  m, 6 seconds for 3.81 × 10-4  m, 8 seconds for 5.08 × 10-4  m, and 14 seconds for 6.35 × 10-4  m skin thickness.

CONCLUSIONS

This study has characterized the correlation between thermal stimulus input and resolvable object size and depth for ADT. Through ex vivo experimentation it has also quantified the functional imaging depth to below the sub-cutis, beyond that of conventional imaging techniques. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Dedicated tool to assess the impact of a rhetorical task on human body temperature

INTRODUCTION

Functional infrared thermal imaging is a method widely used in medicine, including analysis of the mechanisms related to the effect of emotions on physiological processes. The article shows how the body temperature may change during stress associated with performing a rhetorical task and proposes new parameters useful for dynamic thermal imaging measurements MATERIALS AND METHODS: 29 healthy male subjects were examined. They were given a rhetorical task that induced stress. Analysis and processing of collected body temperature data in a spatial resolution of 256×512pixels and a temperature resolution of 0.1°C enabled to show the dynamics of temperature changes. This analysis was preceded by dedicated image analysis and processing methods RESULTS: The presented dedicated algorithm for image analysis and processing allows for fully automated, reproducible and quantitative assessment of temperature changes and time constants in a sequence of thermal images of the patient. When performing the rhetorical task, the temperature rose by 0.47±0.19°C in 72.41% of the subjects, including 20.69% in whom the temperature decreased by 0.49±0.14°C after 237±141s. For 20.69% of the subjects only a drop in temperature was registered. For the remaining 6.89% of the cases, no temperature changes were registered CONCLUSIONS: The performance of the rhetorical task by the subjects causes body temperature changes. The ambiguous temperature response to the given stress factor indicates the complex mechanisms responsible for regulating stressful situations. Stress associated with the examination itself induces body temperature changes. These changes should always be taken into account in the analysis of infrared data.

Infant skin maturation: Preliminary outcomes for color and biomechanical properties

BACKGROUND

Newborn infant skin changes after birth but studies have focused on the epidermal barrier. Dermal properties are relevant for care, but literature on postnatal changes is sparse. We further characterized skin maturational changes in lightness, color and response to biomechanical stress.

METHODS

Normal skin sites from subsets of participants in a trial on the progression and stage of infantile hemangiomas were retrospectively examined. Standardized photographs were analyzed as L*, a*, and b* images. Biomechanics were measured with the Cutometer^® .

RESULTS

Color changed significantly with increasing age. Skin was darker and redder at 2.0 vs. 5.4, 8.5 and 12.8 months. Yellow color increased, with higher values at 12.8 vs. 2.0, 3.5 and 5.4 months. Chest tissue was consistently more elastic than arm and face sites, with significantly higher elasticity for the youngest and oldest age groups. Biological elasticity, elastic recovery, and total recovery were significantly greater for the oldest subjects. Viscoelasticity and elastic deformation were lower at 5.5 vs. 8.8 and 17.6 months. Arm viscoelastic creep was highest at 2.8 months.

CONCLUSION

Skin maturation continues into year two. Increasing elasticity and decreasing viscoelasticity may reflect increased collagen structure/function. The findings have implications for prevention of skin injury associated with mechanical forces.