Kevin Howell

Evaluation of methotrexate and corticosteroids for the treatment of localized scleroderma (morphoea) in children.

Background  Localized scleroderma (LS) or morphoea is often considered to be a benign self‐limiting condition confined to the skin and subcutaneous tissue. However, the course of the disease is unpredictable and severe functional and cosmetic disability may result. Drug treatment with systemic corticosteroids in combination with methotrexate has been reported to be beneficial in LS, but data in children is limited.

Microvascular imaging: techniques and opportunities for clinical physiological measurements

The microvasculature presents a particular challenge in physiological measurement because the vessel structure is spatially inhomogeneous and perfusion can exhibit high variability over time. This review describes, with a clinical focus, the wide variety of methods now available for imaging of the microvasculature and their key applications. Laser Doppler perfusion imaging and laser speckle contrast imaging are established, commercially-available techniques for determining microvascular perfusion, with proven clinical utility for applications such as burn-depth assessment. Nailfold capillaroscopy is also commercially available, with significant published literature that supports its use for detecting microangiopathy secondary to specific connective tissue diseases in patients with Raynauds phenomenon. Infrared thermography measures skin temperature and not perfusion directly, and it has only gained acceptance for some surgical and peripheral microvascular applications. Other emerging technologies including imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging are also described to show their potential as techniques that could become established tools for clinical microvascular assessment. Growing interest in the microcirculation has helped drive the rapid development in perfusion imaging of the microvessels, bringing exciting opportunities in microvascular research.

COMPARISON OF LASER-DOPPLER PERFUSION IMAGING, LASER-DOPPLER FLOWMETRY, AND THERMOGRAPHIC IMAGING FOR ASSESSMENT OF BLOOD-FLOW IN HUMAN SKIN

In this study we compared three non-invasive methods of measuring skin perfusion, thermographic imaging (TI), laser Doppler flowmetry (LDF) and the new technique of laser Doppler imaging (LDI). Seven normal volunteers were studied in a temperature-controlled room with an ambient temperature of 22 +/- 1 degree C. Images of the left hand were recorded using LDI followed by TI. LDF was then used on two standard locations on the fingers and back of the hand. The measurements were then repeated for a hot (37 degrees C) and then a cold (10 degrees C) challenge. A significant linear correlation (r = 0.960, p < 0.01, with 95% confidence limit of 0.35-0.77, n = 38) was found between LDF and LDI. However, LDF and LDI did not correlate well with TI (r = 0.577, p < 0.01, with 95% confidence limit of 0.32-0.76, n = 38). The LDI method was found to be highly reproducible (mean +/- 1 SD; 625 +/- 30, with coefficient of variation 5%). The blood flow and temperature distribution of skin of the hand was then recorded using TI and LDI in 10 patients (mean age +/- SD, 41.7 +/- 9.9) with scleroderma and eight normal volunteers (mean age +/- SD, 30.6 +/- 6.5). The overall mean blood flow and temperature in the hands of patients with scleroderma (mean +/- SD 444 +/- 265 flux, 29.3 +/- 3.3 degrees C) was significantly (p < 0.0001) lower compared with the normal volunteers (mean +/- SD, 912 +/- 390 flux, 34.0 +/- 3.2 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of a protocol for the assessment of skin temperature and blood flow in childhood localised scleroderma

Background/purpose: Localised scleroderma (LS) is the most common form of scleroderma seen in children, and usually presents unilaterally. Infrared thermography (IRT) and laser Doppler (LD) have both been reported to be useful in assessing the active, inflammatory stage of LS. We developed and validated a protocol using these techniques for the assessment of unilateral LS activity in children.

Impact of Hallmark Autoantibody Reactivity on Early Diagnosis in Scleroderma

Raynauds phenomenon often precedes the diagnosis of systemic sclerosis and is the first symptom of the disease in many cases. Antinuclear antibody positivity can assist in the early identification of cases of isolated Raynauds phenomenon likely to progress to systemic sclerosis. However, the specific differences between rate of progression for different scleroderma hallmark antibodies is less clear. We review the predictive potential of ANA positivity and nailfold capillaroscopy for identifying cases of Raynauds phenomenon which may progress to connective tissue diseases. We also have reviewed data from our own large scleroderma cohort to explore the relationship between antibody subtype and time to development of SSc. Duration of pre-existing Raynauds phenomenon may be an important determinant of the profile of systemic sclerosis cases identified through screening. Ninety-five percent of our patients with isolated Raynauds phenomenon, negative autoimmune serology on more than one visit and normal capillaroscopy score showed no progression to connective tissue disease. Duration of antecedent Raynauds phenomenon differs between disease subsets and scleroderma-specific ANA patterns.

Infrared Thermography: Current Applications in Equine Medicine

Abstract Infrared thermography is an imaging technique, mapping body surface temperature changes which may indicate inflammatory, vascular, or neurological disorders. The proper use of thermography to evaluate surface thermal patterns requires a controlled environment and rigorous adherence to an imaging protocol to eliminate errors of interpretation. Thermography plays an important role as a complementary diagnostic tool in veterinary medicine, indicating any areas of abnormality and suggesting where to concentrate further diagnostic imaging or treatment. During the healing process, it can quantify the regression of inflammation or monitor the efficacy of anti‐inflammatory medication. However, the specificity and sensitivity of thermography can be limited for many applications, and it is therefore most valuable as an adjunct to other modalities and should always be performed under veterinary guidance. More research is required to confirm the reproducibility of the technique, especially during long‐term follow‐up. This review considers the evidence for the utility of thermography in equine medicine practice and presents its current advantages and limitations. HighlightsThermography plays an important complementary role in early detection of pathology.Thermography provides physiological information about an injury and aids localization.Therefore it is most valuable when combined with other modalities.

The effect of ambient temperature on infrared thermographic images of joints in the distal forelimbs of healthy racehorses

The aim of the study was to describe the dependence on ambient temperature of distal joint temperature at the forelimbs of racehorses. The study also investigated the influence of differing ambient temperatures on the temperature difference between joints: this was measured ipsilaterally (i.e. between the carpal and fetlock joints along each forelimb) and contralaterally (i.e. between the same joints of the left and right forelimbs). Sixty-four healthy racehorses were monitored over 10 months. At each session, three thermographic images were taken of the dorsal, lateral and medial aspects of the distal forelimbs. Temperature measurements were made from regions of interest (ROIs) covering the carpal and fetlock joints. There was a strong correlation between ambient temperature and absolute joint temperature at all ROIs. The study also observed a moderate correlation between ambient temperature and the ipsilateral temperature differences between joints when measured from the medial and lateral aspects. No significant correlation was noted when measured dorsally. The mean contralateral temperature differences between joints were all close to 0°C. The data support previous reports that the temperature distribution between the forelimbs of the healthy equine is generally symmetric, although some horses differ markedly from the average findings.

The influence of breed, age, gender, training level and ambient temperature on forelimb and back temperature in racehorses

A previous thermographic study of racehorses identified 13 regions of interest (ROIs) for monitoring the impact of training. However, that investigation did not consider the influence of breed, age, gender or training intensity level on the temperature of ROIs. The present study adopted a multivariate analysis approach to determine whether the aforementioned factors, along with ambient temperature, significantly influenced ROI temperature in the key body regions. Thermography measurements were obtained from 53 racehorses of three breeds. Horses were in regular training for over 10 months, having 13 thermographic examinations in each racing season. Backward stepwise multiple linear regression indicated that ambient temperature and breed contributed significantly to the model for predicting ROI temperature at all 13 ROIs. Training intensity level contributed significantly to the model only at the thoracic vertebrae, the left third metacarpal bone and left fetlock joint. Neither gender nor age contributed to the model significantly at any ROI. Our data suggest that ambient temperature, breed and training level affect racehorse body surface temperature in some areas of the distal parts of the forelimbs and the back. This contributes to a better understanding of the normal range of thermographic findings in racehorses undergoing intensive training.

Assessment of Saddle Fit in Racehorses Using Infrared Thermography

&NA; The aim of this study was to assess the influence of horse, saddle, and rider on saddle fit in racehorses by detecting pressure distribution using infrared thermography. In this study, 22 saddles used on 65 racing horses ridden by 21 riders were used. Data from horses including gender, breed, age, training intensity, and level of performance were collected. Type and mass of the saddle were also obtained, along with information about the riders body mass and riding skills. Thermographic images of the saddles panels were captured immediately after untacking the horse at each thermographic examination. On each thermographic image of the saddle panels, six regions of interest (ROIs) were marked, with mean temperature calculated within each ROI to indicate pressure distribution. Saddle fit was evaluated for right/left panel pressure, bridging/rocking pressure, and front/back pressure according to horses: gender, breed, age, training intensity, level of conditioning, riders skills, and load (saddle plus rider mass). There were statistically significant relationships (P < .05) between left/right asymmetry and age, training, intensity and load. In front/back pressure, there was a statistically significant relationship (P < .05) for load. No statistically significant relationships were observed between bridging/rocking pressure and the rest of the aforementioned variables. The study indicated that load, horse age, and training intensity influence pressure distribution in racing saddles. Therefore, animal age and load have to be considered in saddle fit. Infrared thermography has been confirmed as a useful tool in the evaluation of saddle fit in racing horses. HighlightsLoad and horse age influence pressure distribution of the saddle fit.Horse age and load have to be considered in saddle fit in racing horses.Infrared thermography is a useful tool in the evaluation of saddle fit.

A Pilot Study Into the Utility of Dynamic Infrared Thermography for Measuring Body Surface Temperature Changes During Treadmill Exercise in Horses

ABSTRACT The aim of the study was to investigate the feasibility of evaluating heat loss from the body surface of horses during exercise on a treadmill using dynamic infrared thermography (IRT). Continuous measurements of body surface temperature change at walk, trot, and during recovery time were collected from five horses using a thermographic camera. Horses were exercised on the treadmill for 25 minutes: 10 minutes of walk, 10 minutes of trot, 5 minutes of walk, and ending with 10 minutes of recovery time. Four thermograms per minute were extracted from the original 30 Hz video sequences for temperature analysis. Four regions of interest (ROIs) were positioned on each analyzed thermographic image including neck (NC), shoulder (SH), chest (CH), and croup area. At baseline, the NC was the hottest ROI, followed by the SH. By the end of the first walk, the temperature at all ROIs had increased, with the NC area remaining the warmest. During the trot, temperature increased for the first 5 minutes, with the greatest increase in temperature in the CH area. During the second walk, the temperatures started to decline in all regions. By the end of the recovery period, temperature had reduced at all regions, with the NC and CH areas demonstrating the biggest drop in temperature. It was found that heat loss from the body surface during exercise can be evaluated by means of dynamic body surface temperature measurement with IRT. More research is now required to fully explore the physiological changes of the equine musculoskeletal system during exercise. HighlightsHeat loss is evaluated by means of dynamic body surface temperature measurement.Dynamic temperature measurement provided information on heat dissipation.Thermography is a technique which reveals the evolution of temperature in real time.