Between visit variability of thermal imaging of feet in people attending podiatric clinics with diabetic neuropathy at high risk of developing foot ulcers.

OBJECTIVE: People with diabetic neuropathy who have previously ulcerated are at high risk of re-ulceration. They should regularly attend podiatry clinics for surveillance and routine protective podiatric treatment. It has been suggested that inflammation prior to skin breakdown shows up as a hotspot on a thermal image even in the absence of clinical signs. The aim of this study is to quantify inter-patient and intra-patient thermal variations presented by diabetic feet at high risk of ulceration. APPROACH: Whole foot and spot temperatures were recorded for 96 patients who attended two successive podiatry appointments without ulceration 28 [28, 31] days apart, median [interquartile range]. This was a part of a longer study into whether thermal imaging in clinic can reduce the rate of re-ulceration. MAIN RESULTS: The variation in spot temperature right/left differences for single patients between visits was comparable to the variation observed between patients (0.8 [0.3, 1.5] °C compared with 0.9 [0.4, 1.7] °C). Similarly, whole foot temperature variation for a single patient between visits was comparable to the variation observed between patients (0.6 [0.2, 1.1] °C compared with 0.8 [0.2, 1.3] °C). SIGNIFICANCE: Thresholds which depend on thermal differences from visit to visit are unlikely to have sufficient specificity to effectively target treatment designed to prevent the development of foot ulcers.

A Multicenter Study of the Validity and Reliability of Responses to Hand Cold Challenge as Measured by Laser Speckle Contrast Imaging and Thermography: Outcome Measures for Systemic Sclerosis-Related Raynaud's Phenomenon.

OBJECTIVE: Reliable and objective outcome measures to facilitate clinical trials of novel treatments for systemic sclerosis (SSc)-related Raynaud's phenomenon (RP) are badly needed. Laser speckle contrast imaging (LSCI) and thermography are noninvasive measures of perfusion that have shown excellent potential. This multicenter study was undertaken to determine the reliability and validity of a hand cold challenge protocol using LSCI, standard thermography, and low-cost cell phone/mobile phone thermography (henceforth referred to as mobile thermography) in patients with SSc-related RP. METHODS: Patients with RP secondary to SSc were recruited from 6 UK tertiary care centers. The patients underwent cold challenge on 2 consecutive days. Changes in cutaneous blood flow/skin temperature at each visit were imaged simultaneously using LSCI, standard thermography, and mobile thermography. Measurements included area under the curve (AUC) for reperfusion/rewarming and maximum blood flow rate/skin temperature after rewarming (MAX). Test-retest reliability was assessed using intraclass correlation coefficients (ICCs). Estimated latent correlations (estimated from multilevel models, taking values between -1 and 1; denoted as rho values) were used to assess the convergent validity of LSCI and thermography. RESULTS: In total, 159 patients (77% with limited cutaneous SSc) were recruited (84% female, median age 63.3 years). LSCI and standard thermography both had substantial reliability, with ICCs for the reperfusion/rewarming AUC of 0.67 (95% confidence interval [95% CI] 0.54, 0.76) and 0.68 (95% CI 0.58, 0.80), respectively, and ICCs for the MAX of 0.64 (95% CI 0.52, 0.75) and 0.72 (95% CI 0.64, 0.81), respectively. Very high latent correlations were present for the AUCs of LSCI and thermography (ρ = 0.94; 95% CI 0.87, 1.00) and for the AUCs of standard and mobile thermography (ρ = 0.98; 95% CI 0.94, 1.00). CONCLUSION: This is the first multicenter study to examine the reliability and validity of cold challenge using LSCI and thermography in patients with SSc-related RP. LSCI and thermography both demonstrated good potential as outcome measures. LSCI, standard thermography, and mobile thermography had very high convergent validity.

Thermal symmetry of healthy feet: a precursor to a thermal study of diabetic feet prior to skin breakdown.

Early identification of areas of inflammation may aid prevention of diabetic foot ulcers. A new bespoke thermal camera system has been developed to thermally image feet at risk. Hotspots (areas at least 2.2 °C hotter than the contralateral site) may indicate areas of inflammation prior to any apparent visual signs. This article describes the thermal pattern and symmetry of 103 healthy pairs of feet. 68% of participants were thermally symmetric at the 33 foot sites measured. 32% of participants had at least one hotspot, but hotspots overall only accounted for 5% of the measurements made. Refinements to the definition of hotspots are proposed when considering feet at risk of ulceration.

Evaluation of potential predictors of outcome of laser-assisted uvulopalatoplasty for snoring.

OBJECTIVE: Laser-assisted uvulopalatoplasty (LAUP) is a common treatment for snoring, but up to 50% of patients obtain little or no sustained benefit. We investigated whether pre-operative measurements from lateral cephalometry, acoustic rhinometry, analysis of snoring sounds, and body mass index (BMI) could predict which snorers benefited from LAUP. STUDY DESIGN AND SETTING: Fifty-five snoring patients were assessed pre- and 6 months post-LAUP. Snoring severity was assessed by objective sound level recorded during polysomnography, and a Snoring Symptoms Inventory (SSI) questionnaire. RESULTS: The outcome of surgery was assessed by changes in objective sound measurements and in SSI, 6 months after LAUP. CONCLUSIONS: Relationships between the predictive measurements and outcome were at best only weak and none had sufficient predictive value to be useful in clinical practice.