Thermography Abstracts

J Am Vet Med Assoc. 2013 Feb 1;242(3):388-95. doi: 10.2460/javma.242.3.388.

Effects of infrared camera angle and distance on measurement and reproducibility of thermographically determined temperatures of the distolateral aspects of the forelimbs in horses.

Westermann S, Buchner HH, Schramel JP, Tichy A, Stanek C. Source

Units of Large Animal Surgery and Orthopaedics, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria.

Abstract

OBJECTIVE:

To assess effects of camera angle and distance on measurement and reproducibility of thermographically determined temperatures of the distolateral aspect of the forelimbs in horses.

DESIGN:

Evaluation study.

ANIMALS:

10 adult horses.

PROCEDURES:

Thermographic images of both forelimbs were obtained at 3 times during the day (replicates 1, 2, and 3); maximum surface temperature over 1 region (distolateral aspect of the third metacarpal bone and metacarpophalangeal joint) was measured. Standard images were obtained every 5 minutes for 1 hour with the camera positioned at an angle of 90° and a distance of 1.0 m from the forelimb; additional images were obtained at changed (± 20°) angles or at a 1.5-m distance. At the end of each replicate, 4 sets of additional images were obtained at 2-minute intervals to assess short-term reproducibility.

RESULTS:

Mean ± SD temperature difference between left and right forelimbs was 0.32° ± 0.27°C (0.58° ± 0.49°F) in standard images. Temperatures measured via standard images were highly correlated with those measured with the camera positioned at changed angles or distance. Mean ± SD differences between temperatures measured via standard images and those measured from changed angles or distance were considered small (≤ 0.22° ± 0.18°C [0.40° ± 0.32°F] for all comparisons). The degree of short-term reproducibility was high.

CONCLUSIONS AND CLINICAL RELEVANCE:

Thermographically determined temperatures were unaffected by 20° changes in camera angle or a 0.5-m increase in camera distance from the forelimb. Minor temperature differences between left and right forelimbs were detected in the study and should be considered during diagnostic investigations.

Equine Vet J. 2013 Sep;45(5):637-41. doi: 10.1111/evj.12019. Epub 2013 Jan 7.

The effect of airflow on thermographically determined temperature of the distal forelimb of the horse.

Westermann S, Stanek C, Schramel JP, Ion A, Buchner HH.

Source

Large Animal Surgery and Orthopaedics, University of Veterinary Medicine Vienna (Vetmeduni Vienna), Vienna, Austria.

Abstract

REASONS FOR PERFORMING STUDY:

Current literature suggests that thermographic imaging of horses should be performed in a draught-free room. However, studies on the effect of airflow on determined temperature have not been published.

OBJECTIVES:

To investigate effects of airflow on thermographically determined temperature of horses' forelimbs; to assess the relationship of wind velocity, rectal temperature, ambient temperature and humidity.

METHODS:

Thermographic images were obtained for the forelimbs of 6 horses in a draught-free room. Three replicates (R) with defined wind velocities (R1, 0.5-1.0 m/s; R2, 1.3-2.6 m/s; and R3, 3.0-4.0 m/s) were conducted. Each replicate consisted of a baseline image, a 15 min phase with the wind on and a 15 min phase with the wind off. We exposed only the right leg to airflow and determined the temperature by thermography with the wind on and wind off. Temperature differences between baseline and wind on, between wind on and wind off and between different wind velocities were analysed by a general linear model, Student's paired t test and ANOVA.

RESULTS:

After the onset of wind, the temperature on the right forelimb decreased within 1-3 min (by approximately 0.6°C at R1, 1.5°C at R2 and 2.1°C at R3). With the wind off, the temperature increased within 3 min (by approximately 1.2°C at R1, 1.7°C at R2 and 2.1°C at R3). With increasing wind velocity, the temperature differences between baseline and wind on and between wind on and wind off increased significantly.

CONCLUSIONS:

Barely noticeable wind velocities caused a decrease in thermographically determined temperatures of the forelimbs of the horse. Further research is required to assess the influence of airflow on other parts of the body and at different ambient temperatures, as well as the effect on horses with inflammatory lesions, especially of the distal limbs.

POTENTIAL RELEVANCE:

It is essential for practitioners to perform thermography on horses in a draught-free environment in order to avoid false-positive or -negative diagnoses.

Vet Anaesth Analg. 2013 Mar;40(2):142-8. doi: 10.1111/j.1467-2995.2012.00768.x. Epub 2012 Aug 14.

Thermographic imaging of superficial temperature in dogs sedated with medetomidine and butorphanol with and without MK-467 (L-659'066).

Vainionpää M, Salla K, Restitutti F, Raekallio M, Junnila J, Snellman M, Vainio O.

Source

Department of Equine and Small Animal Medicine, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Helsinki, Finland 4Pharma Ltd, Espoo, Finland.

Abstract

OBJECTIVE:

To record, with a thermal camera, peripheral temperature changes during different sedation protocols and to relate the results to changes in the rectal temperature.

STUDY DESIGN:

Randomized crossover part-blinded experimental study.

ANIMALS:

Eight healthy purpose-bred neutered Beagles (two females and six males) weight 14.5 ± 1.6 kg (mean ± SD) and aged 3-4 years.

METHODS:

Each dog was sedated four times. Treatments were medetomidine 20 μg kg(-1) and butorphanol 0.1 mg kg(-1) (MB) with or without MK-467 500 μg kg(-1) (MK). Both drug combinations were administered IV and IM as separate treatments. A thermal camera (T425, FLIR) with a resolution of 320 by 240 was used for imaging. The dogs were placed in lateral recumbency on an insulated mattress. Digital (DFT) and metatarsal footpad temperatures (MFT) were measured with thermography. Thermograms and rectal temperature (RT) were taken before and at 3, 10, 20, 30, 45 and 60 minutes after treatment.

RESULTS:

At 60 minutes after drug administration, MFT was higher (p < 0.001) after MB+MK (34.5 ± 1.1 IV, 34.8 ± 0.5 IM) than MB (31.1 ± 2.9 IV, 30.5 ± 3.6 IM), DFT was higher (p < 0.001) after MB+MK (33.6 ± 1.4 IV, 34.0 ± 0.6 IM) than MB (26.7 ± 1.4 IV, 26.7 ± 2.5 IM), and RT was lower (p < 0.001) after MB+MK (36.7 ± 0.8 IV, 36.9 ± 0.3 IM) than MB (37.5 ± 0.3 IV, 37.4 ± 0.4 IM), with both routes. The change from baseline was greater with MB+MK than MB in all variables.

CONCLUSIONS:

Superficial temperature changes can be seen and detected with thermography. MK-467 used with MB resulted in increased superficial temperatures and a decline in rectal temperature compared to MB alone.

CLINICAL RELEVANCE:

The sedation protocol may influence core temperature loss, and may also have an effect on thermographic images.

J Vet Med Sci. 2012 Dec;74(12):1539-44. Epub 2012 Jul 9.

Comparison of three thermal cameras with canine hip area thermographic images.

Vainionpää M, Raekallio M, Tuhkalainen E, Hänninen H, Alhopuro N, Savolainen M, Junnila J, Hielm-Björkman A, Snellman M, Vainio O.

Source

Department of Equine and Small Animal Medicine, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Helsinki, Koetilantie 7, Finland.

Abstract

The objective of this study was to compare the method of thermography by using three different resolution thermal cameras and basic software for thermographic images, separating the two persons taking the thermographic images (thermographers) from the three persons interpreting the thermographic images (interpreters). This was accomplished by studying the repeatability between thermographers and interpreters. Forty-nine client-owned dogs of 26 breeds were enrolled in the study. The thermal cameras used were of different resolutions-80 × 80, 180 × 180 and 320 × 240 pixels. Two trained thermographers took thermographic images of the hip area in all dogs using all three cameras. A total of six thermographic images per dog were taken. The thermographic images were analyzed using appropriate computer software, FLIR QuickReport 2.1. Three trained interpreters independently evaluated the mean temperatures of hip joint areas of the six thermographic images for each dog. The repeatability between thermographers was >0.975 with the two higher-resolution cameras and 0.927 with the lowest resolution camera. The repeatability between interpreters was >0.97 with each camera. Thus, the between-interpreter variation was small. The repeatability between thermographers and interpreters was considered high enough to encourage further studies with thermographic imaging in dogs.

Theriogenology. 2009 Aug;72(3):372-7. doi: 10.1016/j.theriogenology.2009.03.005. Epub 2009 May 30.

Assessment of pregnancy in the late-gestation mare using digital infrared thermography.

Bowers S, Gandy S, Anderson B, Ryan P, Willard S.

Source

Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762, USA.

Abstract

The objective of this study was to investigate use of digital infrared thermal imaging (DITI) to determine whether surface temperature gradient differences exist between pregnant and nonpregnant mares as a noncontact method to determine pregnancy status. On the day measurements were collected, each pregnant mare (n=10; beginning at 292.4+/-1.4 d of gestation) was paired with a nonpregnant mare (n=17). Ambient temperature, DITI measurements (left and right flank, wither temperatures [i.e., animal surface control] and background temperature), and rectal temperatures were obtained every 7 d for 5 wk before parturition and for 3 wk after parturition. There were no differences (P>0.10) in temperature of the left and right side within groups; therefore, data were pooled. Pregnant mares had a higher (P<0.01) flank temperature than that of nonpregnant mares (36.0+/-0.2 degrees C vs. 34.2+/-0.2 degrees C, respectively). Moreover, the difference (2.4 degrees C) in flank temperatures between the pregnant and nonpregnant mares was greater when the ambient temperature was <19 degrees C. Flank and wither temperatures were positively correlated (R=0.72; P<0.01) and were positively correlated with ambient temperature (R=0.48 and 0.64, respectively; P<0.01). However, wither temperatures (skin control site) did not differ (P>0.10) between pregnant and nonpregnant mares. In conclusion, late-gestation mares had higher flank temperatures than those of nonpregnant mares, regardless of environmental conditions, however discriminating abilities were greater when ambient temperature was lower. We inferred that DITI may have value in confirming mid- to late-gestation pregnancies in some species by noncontact means, as observed in the mare.

Equine Vet J. 2009 Jan;41(1):18-23.

Distal limb cast sores in horses: risk factors and early detection using thermography.

Levet T, Martens A, Devisscher L, Duchateau L, Bogaert L, Vlaminck L.

Source

Department of Large Animal Surgery and Anaesthesiology, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.

Abstract

REASONS FOR PERFORMING STUDY:

There is a lack of evidence-based data on the prevalence, outcome and risk factors of distal limb cast sores, and no objective tool has been described for the early detection of cast sores.

OBJECTIVES:

To investigate the prevalence, location, outcome and risk factors of cast sores after application of a distal limb cast and to determine whether static thermography of the cast is a valuable tool for the assessment of sores.

METHODS:

A prospective study was conducted on horses treated with a distal limb cast. At each cast removal, cast sores were graded as superficial sores (SS), deep dermal sores (DS) or full thickness skin ulcerations (FS). In several cases, a thermographic evaluation of the cast was performed immediately prior to removal and differences in temperature (AT) between the coolest point of the cast and 2 cast regions predisposed for sore development (dorsoproximal mc/mtIII and palmar/plantar fetlock) were calculated.

RESULTS:

Mean +/- s.d. total casting time of 70 horses was 31 +/- 18 days. Overall, 57 legs (81%) developed at least SS. Twenty-four legs (34%) ultimately developed DS and one horse had an FS. Multivariable analysis showed that the severity of sores was positively associated with increasing age (OR: 1.111, P = 0.028), a normal (vs. swollen) limb (OR: 3387, P = 0.023) and an increase in total casting time (OR per week: 1.363, P = 0.002). The thermographic evaluation (35 casts) revealed that the severity of sores was positively associated with increasing deltaT (OR: 2.100, P = 0.0005). The optimal cut-off values for the presence of SS and DS were set at, respectively, deltaT = 23 and 43 degrees C.

CONCLUSION AND POTENTIAL RELEVANCE:

Distal limb cast is a safe coaptation technique with increasing risk of developing sores with time. Thermography is a valuable and rapid clinical tool to monitor the development of cast sores.

Influence of exercise on thermographically determined surface temperatures of thoracic and pelvic limbs in horses.

Simon EL, Gaughan EM, Epp T, Spire M.

Source

Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA.

Abstract

OBJECTIVE:

To determine the amount of time required for surface temperatures of thoracic and pelvic limbs in horses to return to pre-exercise temperatures after high-speed treadmill exercise, as detected via infrared thermographic imaging.

DESIGN:

Prospective study.

ANIMALS:

6 Thoroughbreds.

PROCEDURES:

All horses had been trained on and conditioned to use of a high-speed treadmill. Baseline thermographic images were obtained 3 days prior to exercise (baseline). Horses were exercised on a treadmill at a walk for 5 minutes, a slow trot (3 m/s) for 5 minutes, a trot (5 to 6 m/s) for 5 minutes, and a slow gallop (6 to 8 m/s) for 5 minutes, then back to a trot for 3 minutes, a slow trot for 3 minutes, and a walk for 3 minutes prior to stopping. Thermal images were obtained immediately after stopping exercise (0 minutes) and 5, 15, 45, and 60 minutes and 6 hours after stopping exercise. Ambient temperature surrounding each horse was recorded.

RESULTS:

In all regions, significant differences in surface temperatures were detected between thermograms obtained before exercise and those obtained immediately after, 5 minutes after, and 15 minutes after exercise was stopped. There were no significant differences in surface temperatures between thermograms obtained before exercise and those obtained > or = 45 minutes after exercise was stopped.

CONCLUSIONS AND CLINICAL RELEVANCE:

In horses, images generated via infrared thermography are not influenced by exercise-generated heat > or = 45 minutes after exercise is stopped.

Equine Vet J. 2004 May;36(4):306-12.

Reliability and repeatability of thermographic examination and the normal thermographic image of the thoracolumbar region in the horse.

Tunley BV, Henson FM.

Source

Queen's Veterinary School Hospital, Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, Cambridgeshire CB3 0ES, UK.

Abstract

REASONS FOR PERFORMING STUDY:

Thermographic imaging is an increasingly used diagnostic tool. When performing thermography, guidelines suggest that horses should be left for 10-20 mins to 'acclimatise' to the thermographic imaging environment, with no experimental data to substantiate this recommendation. In addition, little objective work has been published on the repeatability and reliability of the data obtained. Thermography has been widely used to identify areas of abnormal body surface temperature in horses with back pathology; however, no normal data is available on the thermographic 'map' of the thoracolumbar region with which to compare horses with suspected pathology.

OBJECTIVES:

To i) investigate whether equilibration of the thermographic subject was required and, if so, how long it should take, ii) investigate what factors affect time to equilibration, iii) investigate the repeatability and reliability of the technique and iv) generate a topographic thermographic 'map' of the thoracolumbar region.

METHODS:

A total of 52 horses were used. The following investigations were undertaken: thermal imaging validation, i.e. detection of movement around the baseline of an object of constant temperature; factors affecting equilibration; pattern reproducibility during equilibration and over time (n = 25); and imaging of the thoracolumbar region (n = 27).

RESULTS:

A 1 degrees C change was detected in an object of stable temperature using this detection system, i.e the 'noise' in the system. The average time taken to equilibrate, ie. reach a plateau temperature, was 39 mins (40.2 in the gluteal region, 36.2 in lateral thoracic region and 40.4 in metacarpophalangeal region). Only 19% of horses reached plateau within 10-20 mins. Of the factors analysed hair length and difference between the external environment and the internal environment where the measurements were being taken both significantly affected time to plateau (P<0.05). However, during equilibration, the thermographic patterns obtained did not change, nor when assessed over a 7 day period. A 'normal' map of the surface temperature of the thoracolumbar region has been produced, demonstrating that the midline is the hottest, with a fall off of 3 degrees C either side of the midline.

CONCLUSIONS:

This study demonstrates that horses may not need time to equilibrate prior to taking thermographic images and that thermographic patterns are reproducible over periods up to 7 days. A topographical thermographic 'map' of the thoracolumbar region has been obtained.

POTENTIAL RELEVANCE:

Clinicians can obtain relevant thermographic images without the need for prior equilibration and can compare cases with thoracolumbar pathology to a normal topographic thermographic map.

Behav Res Methods Instrum Comput. 2003 Aug;35(3):429-39.

Infrared imaging technology and biological applications.

Kastberger G, Stachl R.

Source

Institute of Zoology, University of Graz, Graz, Austria.

Abstract

Temperature is the most frequently measured physical quantity, second only to time. Infrared (IR) technology has been utilized successfully in astronomy (for a summary,see Hermans-Killam, 2002b) and in industrial and research settings (Gruner, 2002; Madding, 1982, 1989; Wolfe & Zissis, 1993) for decades. However, fairly recent innovations have reduced costs, increased reliability, and resulted in noncontact IR sensors offering mobile, smaller units of measurement (EOI, 2002; Flir, 2000, 2001,2002). The advantages of using IR imaging are (1) rapidity in the millisecond range, facilitating measurement of moving targets, (2) noncontact procedures, allowing measurements of hazardous or physically inaccessible objects, (3) no interference and no energy lost from the target, (4) no risk of contamination, and (5) no mechanical effect on the surface of the object. All these factors have led to IR technology's becoming an area of interest for new kinds of applications and users. In both manufacturing and quality control, temperature plays an important role as an indicator of the condition of a product or a piece of machinery (EOI, 2002; Flir, 2000, 2001, 2002; Raytek, 2002). In medical and veterinary applications, IR thermometry is increasingly used in organ diagnostics, in the evaluation of sports injuries and the progression of therapy, in disease evaluation (e.g, breast cancer, arthritis, and SARS; Flir, 2003), and in injury and inflammation examinations in horses, livestock (Tivey & Banhazi, 2002), and zoo animals (Hermans-Killam, 2002a; Thiesbrummel, 2002). Lastly, physiological expressions of life processes in animals (Kastberger, Winder, & Steindl, 2001; Stabentheiner, Kovac, & Hagmüller, 1995; Stabentheiner, Kovac, & Schmaranzer, 2002; Stabentheiner & Schmarnzer, 1987) and plants (Bermadinger-Stabentheiner & Stabentheiner, 1995) can be monitored. The most recent field in which IR technology has been applied is animal behavior. This article focuses on the practical options for noncontact IR thermometry--in particular, in biological applications.