Dis Colon Rectum 2000 Sep;43(9):1319-21
Thermal imaging in the detection of bowel ischemia. Brooks JP, Perry WB, Putnam AT, Karulf RE Department of Colorectal Surgery, Wilford Hall Medical Center, San Antonio, Texas, USA.
PURPOSE: The aim of this study was to introduce thermal imaging in the intraoperative detection of bowel ischemia by comparing thermal imaging with conventional techniques in detecting acutely ischemic bowel, using histologic evidence for intestinal necrosis as the standard. METHODS: A prospective study was performed using a porcine model. Laparotomy was performed on four pigs under general anesthesia. A 25-cm segment of mid jejunum was tagged with proximal and distal sutures, and its mesentery was ligated and divided. Thermal imaging, visual inspection, Doppler ultrasound, and fluorescence with Wood's lamp after fluorescein were used to estimate the extent of bowel ischemia five minutes after ligation of the mesentery. Measurements were taken in reference to both the proximal and distal tags to obtain two data points per animal for each method. After two hours of warm ischemia, the jejunum was harvested and sectioned longitudinally. Comparisons were made between the estimated region of necrosis for each method and microscopic evidence of necrosis. RESULTS: Visual inspection was the only method unable to detect a difference between vascularized and devascularized bowel for each of the eight data points. Fluorescein dye missed 3 cm of ischemic bowel. Doppler ultrasound and thermal imaging were 100 percent sensitive for necrotic bowel, with thermal imaging overestimating necrosis to a greater extent than Doppler ultrasound. The positive predictive value of fluorescein dye, Doppler ultrasound, and thermal imaging for determining nonviable bowel was 91.8, 80.8, and 69.5 percent, respectively. CONCLUSIONS: Thermal imaging has the potential to be a useful adjunct in the intraoperative determination of bowel ischemia. Further studies are indicated to study this technique.
Yonsei Med J 1999 Oct;40(5):401-12
Thermatomal changes in cervical disc herniations. Zhang HY, Kim YS, Cho YE; Department of Neurosurgery, Yongdong Severance Hospital, Yonsei College of Medicine, Seoul, Korea. hyzhang@unitel.co.kr
Subjective symptoms of a cool or warm sensation in the arm could be shown objectively by using of thermography with the detection of thermal change in the case of radiculopathy, including cervical disc herniation (CDH). However, the precise location of each thermal change at CDH has not been established in humans. This study used digital infrared thermographic imaging (DITI) for 50 controls and 115 CDH patients, analyzed the data statistically with t-test, and defined the areas of thermatomal change in CDH C3/4, C4/5, C5/6, C6/7 and C7/T1. The temperature of the upper trunk and upper extremities of the control group ranged from 29.8 degrees C to 32.8 degrees C. The minimal abnormal thermal difference in the right and left upper extremities ranged from 0.1 degree C to 0.3 degree C in 99% confidence interval. If delta T was more than 0.1 degree C, the anterior middle shoulder sector was considered abnormal (p < 0.01). If delta T was more than 0.3 degree C, the medial upper aspect of the forearm and dorsal aspect of the arm, some areas of the palm and anterior part of the fourth finger, and their opposite side sectors and all dorsal aspects of fingers were considered abnormal (p < 0.01). Other areas except those mentioned above were considered abnormal if delta T was more than 0.2 degree C (p < 0.01). In p < 0.05, thermal change in CDH C3/4 included the posterior upper back and shoulder and the anterior shoulder. Thermal change in CDH C4/5 included the middle and lateral aspect of the triceps muscle, proximal radial region, the posterior medial aspect of the forearm and distal lateral forearm. Thermal change in CDH C5/6 included the anterior aspects of the thenar, thumb and second finger and the anterior aspects of the radial region and posterior aspects of the pararadial region. Thermal change in CDH C6/7 included the posterior aspect of the ulnar and palmar region and the anterior aspects of the ulnar region and some fingers. Thermal change in CDH C7/T1 included the scapula and posterior medial aspect of the arm and the anterior medial aspect of the arm. The areas of thermal change in each CDH included wider sensory dermatome and sympathetic dermatome There was a statistically significant change of temperature in the areas of thermal change in all CDH patients. In conclusion, the areas of thermal change in CDH can be helpful in diagnosing the level of disc protrusion and in detecting the symptomatic level in multiple CDH patients.
Nat Biotechnol 1999 Aug;17(8):813-6
Presymptomatic visualization of plant-virus interactions by thermography. Chaerle L, Van Caeneghem W, Messens E, Lambers H, Van Montagu M, Van Der Straeten D; Laboratorium voor Genetica, Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
Salicylic acid (SA), produced by plants as a signal in defense against induces metabolic heating mediated by alternative respiration in flowers of thermogenic plants, and, when exogenously applied, increases leaf temperature in nonthermogenic plants. We have postulated that the latter phenomenon would be detectable when SA is synthesized locally in plant leaves. Here, resistance to tobacco mosaic virus (TMV) was monitored thermographically before any disease symptoms became visible on tobacco leaves. Spots of elevated temperature that were confined to the place of infection increased in intensity from 8 h before the onset of visible cell death, and remained detectable as a halo around the ongoing necrosis. Salicylic acid accumulates during the prenecrotic phase in TMV-infected tobacco and is known to induce stomatal closure in certain species. We show that the time course of SA accumulation correlates with the evolution of both localized thermal effect and stomatal closure. Since the contribution of leaf respiration is marginal, we concluded that the thermal effect results predominantly from localized, SA-induced stomatal closure. The presymptomatic temperature increase could be of general significance in incompatible plant-pathogen interactions.
Laryngorhinootologie 1998 Dec;77(12):677-81
[Thermographic study of temperature gradient during ear surgery intervention].[Article in German] Pau HW, Fichelmann J, Wild W; HNO-Universitatsklinik und Poliklinik Rostock.
BACKGROUND: During middle ear surgery manipulations like burring, cooling with water, suction or even screwing cause changes of temperature which should be known to the surgeon. METHOD: An infrared thermovision device was introduced for registration. RESULTS: Thermography is an easy way for continuously recording thermic effects during surgery. If sufficient cooling is guaranteed, no temperatures high enough to cause tissue damage or functional defects could be observed. CONCLUSIONS: Adequate cooling provided, thermal injuries during ear surgery can be neglected. Thermography is an easy method for answering such questions, not only in ear surgery but also in other medical fields.
J Hand Ther 1999 Oct-Dec;12(4):284-90
Reliability and normal values for measuring the skin temperature of the hand with an infrared tympanic thermometer: a pilot study. Oerlemans HM, Graff MJ, Dijkstra-Hekkink JB, de Boo T, Goris RJ, Oostendorp RA; Allied Health Services, University Hospital Nijmegen, The Netherlands.
Recording asymmetry in skin temperature between symmetric body areas is useful in monitoring diseases that alter skin temperature. This pilot study checked the reported high reliability of recording skin temperature of the hands with an infrared tympanic thermometer, provided insight into the relationship between dorsal and palmar temperature differences, and assessed the agreement between these data and normative data obtained from thermograms. Using an infrared tympanic thermometer, two independent assessors measured the temperature of 13 asymptomatic, right-handed subjects (mean age, 30 years; range, 21 to 44 years). Both test-retest and interobserver reliabilities were high. Skin temperature of the hand differed with the site where it was measured; differences between sites changed over time. The mean absolute differences in skin temperature between dorsal and palmar aspects of the hands were 0.30 degrees C and 0.25 degrees C, respectively. These data match normative values reported in the literature for infrared thermograms.
Rev Neurol 1999 Mar 16-31;28(6):535-43
[Neurophysiological study of thin myelinated and unmyelinated fibers]. [Article in Spanish] Espinosa ML, Santiago S, Guzman JJ, Prieto J, Ferrer T; Laboratorio de SNA, Hospital General La Paz, Madrid, Espana.
INTRODUCTION: Standard neurophysiological techniques evaluate thick myelinated fibers. Yet, peripheral nerves are equally composed of thin myelinated and unmyelinated fibers. The latter are responsible for autonomic function as well as temperature and pain perception. DEVELOPMENT: Microneurographic studies are restricted to investigation laboratories. Since the techniques are complex and invasive, their performance is still poor for clinical purposes and some of the components to be analyzed, such as cardiovagal, cannot be directly recorded. The clinical need to evaluate the functions regulated by the autonomic nervous system (ANS) had led to devising a series of tests which, in most cases, rely on reflex responses evoked by already known standardize stimuli. The battery chosen has to be non invasive, reproducible, specific, providing relevant data to the investigated function, with a readily available technology, which has to be managed being aware of the physiological and pathological factors that might bear an influence on the results. The recent development of heart rate blood pressure power spectral analysis, provides a new interesting insight for quantification of ANS abnormalities. The study of thermography and thermometry of body surface brings forward evidence on the activity of other thin and unmyelinated fibers components of the peripheral nerve spectrum. CONCLUSION: The adequate management of the above mentioned tests gives rise to a more extensive and appropriate knowledge of the whole peripheral nerve fiber spectrum. |
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