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Thermography, mammography, and clinical examination in breast cancer screening. Review of 16,000 studies.

Breast cancer screening detected 139 biopsy-proved malignancies in 16,000 slef-selected women (8.7/1,000). In these, xeroradiography detected 78% (109), clinical examination 55% (76), and thermography 39% (54). In all 16,000 women, the thermogram was interpreted as positive in 17.9% (2,864). The greatest effectiveness of mammography vs. clinical examination was seen in detection of early breast cancers (small lesions with negative axillary lymph nodes). In this group, thermography was less effective than it was in patients with larger lesions and lymph node metastases.

Breast Neoplasms↗

Comparison of IR thermography and thermocouple measurement of heat loss from rabbit pinna.

The temperature of the pinnae of male New Zealand White rabbits was measured by use of infrared thermography. At ambient temperatures of 15, 20, and 25 degrees C, the average pinna temperatures were 23.0, 28.7, and 36.2 degrees C, respectively. From these temperatures, average heat loss from the total pinna surface area was calculated to be 2.8, 3.3, and 4.4 W, respectively. Preoptic temperature changes also affect the vasomotor state of the rabbit. At an ambient temperature of 20 degrees C, cooling the preoptic area of the rabbit by approximately 1 degree C resulted in an average pinna temperature of 26.5 degrees C and a heat loss of 2.4 W. Heating the preoptic area by approximately 1 degree C resulted in an average pinna temperature of 33.5 degrees C and a heat loss of 5.4 W. Finally, pinna temperatures were measured by use of a thermocouple and infrared thermography simultaneously. When the pinnae were vasodilated, the thermocouple measurements were consistently higher than the pinna surface temperatures measured thermographically. When the pinnae were vasoconstricted, the thermocouple measurements were consistently lower than the pinna surface temperatures measured thermographically. The discrepancy between the two methods of measurement is discussed.

Algorithms↗

Noninvasive magnetic resonance thermography of recurrent rectal carcinoma in a 1.5 Tesla hybrid system.

To implement noninvasive thermometry, we installed a hybrid system consisting of a radiofrequency multiantenna applicator (SIGMA-Eye) for deep hyperthermia (BSD-2000/3D) integrated into the gantry of a 1.5 Tesla magnetic resonance (MR) tomograph Symphony. This system can record MR data during radiofrequency heating and is suitable for application and evaluation of methods for MR thermography. In 15 patients with preirradiated pelvic rectal recurrences, we acquired phase data sets (25 slices) every 10 to 15 minutes over the treatment time (60-90 minutes) using gradient echo sequences (echo time = 20 ms), transformed the phase differences to MR temperatures, and fused the color-coded MR-temperature distributions with anatomic T1-weighted MR data sets. We could generate one complete series of MR data sets per patient with satisfactory quality for further analysis. In fat, muscle, water bolus, prostate, bladder, and tumor, we delineated regions of interest (ROI), used the fat ROI for drift correction by transforming these regions to a phase shift zero, and evaluated the MR-temperature frequency distributions. Mean MR temperatures (T(MR)), maximum T(MR), full width half maximum (FWHM), and other descriptors of tumors and normal tissues were noninvasively derived and their dependencies outlined. In 8 of 15 patients, direct temperature measurements in reference points were available. We correlated the tumor MR temperatures with direct measurements, clinical response, and tumor features (volume and location), and found reasonable trends and correlations. Therefore, the mean T(MR) of the tumor might be useful as a variable to evaluate the quality and effectivity of heat treatments, and consequently as optimization variable. Feasibility of noninvasive MR thermography for regional hyperthermia has been shown and should be further investigated.

Antineoplastic Combined Chemotherapy Protocols↗

Infrared thermography in newborns: the first hour after birth.

OBJECTIVE: It was the aim of this study to investigate the surface temperature in newborns within the first hour after delivery. Furthermore, the influence of different environmental conditions with regard to surface temperature was documented. METHODS: Body surface temperature was recorded under several environmental conditions by use of infrared thermography. 42 newborns, all delivered at term and with weight appropriate for date, were investigated under controlled conditions. RESULTS: The surface temperature immediately after birth shows a uniform picture of the whole body; however, it is significantly lower than the core temperature. Soon after birth, peripheral sites become cooler whereas a constant temperature is maintained at the trunk. Bathing in warm water again leads to a more even temperature profile. Radiant heaters and skin-to-skin contact with the mother are both effective methods to prevent heat loss in neonates. CONCLUSIONS: Infrared thermography is a simple and reliable tool for the measurement of skin temperature profiles in neonates. Without the need of direct skin contact, it may be helpful for optimizing environmental conditions at delivery suites and neonatal intensive-care units.

Age Factors↗

Avascular nephrotomy by means of thermography.

Experience with thermography to demarcate the different arterial areas of the kidney is reported. Thermography allows the performance of nephrotomies in an avascular plane with minimal bleeding and subsequent minimal renal parenchymal destruction. It is a safe and simple method which is preferred to the intraarterial injection of dyes which is done for the same purpose.

Hemorrhage↗

Thermal heterogeneity within human atherosclerotic coronary arteries detected in vivo: A new method of detection by application of a special thermography catheter.

BACKGROUND: Activated macrophages play an important role in the pathogenesis of acute ischemic syndromes. It has been postulated that detection of heat released by activated inflammatory cells of atherosclerotic plaques may predict plaque rupture and thrombosis. Previous ex vivo studies have shown that there is thermal heterogeneity in human carotid atherosclerotic plaques. METHODS AND RESULTS: To measure the temperature of human arteries in vivo, we developed a catheter-based technique. Ninety patients (45 with normal coronary arteries, 15 with stable angina [SA], 15 with unstable angina [UA], and 15 with acute myocardial infarction [AMI]) were studied. The thermistor of the thermography catheter has a temperature accuracy of 0.05 degrees C, a time constant of 300 ms, and a spatial resolution of 0.5 mm. Temperature was constant within the arteries of the control subjects, whereas most atherosclerotic plaques showed higher temperature compared with healthy vessel wall. Temperature differences between atherosclerotic plaque and healthy vessel wall increased progressively from SA to AMI patients (difference of plaque temperature from background temperature, 0. 106+/-0.110 degrees C in SA, 0.683+/-0.347 degrees C in UA, and 1. 472+/-0.691 degrees C in AMI). Heterogeneity within the plaque was shown in 20%, 40%, and 67% of the patients with SA, UA, and AMI, respectively, whereas no heterogeneity was shown in the control subjects. CONCLUSIONS: Thermal heterogeneity within human atherosclerotic coronary arteries was shown in vivo by use of a special thermography catheter. This heterogeneity is larger in UA and AMI, suggesting that it may be related to the pathogenesis.

Aged↗

The value of thermography in peripheral vascular disease.

The value of thermography as a reliable, noninvasive, and rapid method of investigating patients with peripheral vascular disease is discussed. Thermography has great value in managing deep venous thrombosis, in estimating the optimal site of amputation, in evaluating vasoactive drugs, and correctly timing the division of pedicled skin flaps. Its use in localizing incompetent perforating veins of the leg and in monitoring patients with cerebrovascular disease after surgery to the carotid arteries is also briefly described.

Amputation, Surgical↗

Abdominal thermography in acute appendicitis.

Abdominal thermography was carried out in 50 patients with suspected acute appendicitis. Forty of these came to laparotomy and in 32 the diagnosis was confirmed. Thermography was not found to be useful in predicting those patients requiring surgery.

Abdomen↗

Uselessness of thermography for diagnosis and follow-up of cutaneous malignant melanoma.

Thermography is useless for diagnosis of cutaneous malignant melanomas (CMM). In fact, false negative thermograms (29.9%) are much more numerous than clinically suspicious cases. Thermography is useless for follow-up of CMM. False-negative and false-positive thermograms of metastatic lymph nodes, subcutaneous nodules and removal site of CMM are much too numerous.

Follow-Up Studies↗

Infrared thermography to mass-screen suspected SARS patients with fever.

Fever greater than 38 degrees C is a cardinal sign of patients with the severe acute respiratory syndromes (SARS). To reduce the risk of nosocomial cross infections, screening all patients and visitors who visit hospitals and clinics for fever at the entrance of every hospital building has become a standard protocol in Taiwan during the SARS epidemic from mid-April to mid-June 2003. We used a digital infrared thermal imaging (DITI) system (Telesis Spectrum 9000 MB) to conduct mass screening of patients and visitors who entered the hospital to identify those with fever. The DITI system has two components: a sensor head and a PC imaging workstation. The sensor head is an optic-mechanical device which consists of imagining optics for focusing the infrared source information on the infrared detector. The infrared images are further converted into electrical signals, which are then processed for real-time display on the monitor. During the period from April 13 to May 12 2003, 72,327 outpatients and visitors entered Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan. A total of 305 febrile patients (0.42%) was detected by infrared thermography. Among them, three probable SARS patients were identified after thorough studies including contact history, laboratory tests and radiology examinations. The findings suggests that infrared thermography was an effective and reliable tool ideal for mass-screening patients with fever in the initial phase of screening for SARS patients at a busy hospital which sees approximately 3,000 outpatients every weekday during the SARS epidemic.

Cross Infection↗

Computer simulation in conjunction with medical thermography as an adjunct tool for early detection of breast cancer.

BACKGROUND: Mathematical modelling and analysis is now accepted in the engineering design on par with experimental approaches. Computer simulations enable one to perform several 'what-if' analyses cost effectively. High speed computers and low cost of memory has helped in simulating large-scale models in a relatively shorter time frame. The possibility of extending numerical modelling in the area of breast cancer detection in conjunction with medical thermography is considered in this work. METHODS: Thermography enables one to see the temperature pattern and look for abnormality. In a thermogram there is no radiation risk as it only captures the infrared radiation from the skin and is totally painless. But, a thermogram is only a test of physiology, whereas a mammogram is a test of anatomy. It is hoped that a thermogram along with numerical modelling will serve as an adjunct tool. Presently mammogram is the 'gold-standard' in breast cancer detection. But the interpretation of a mammogram is largely dependent on the radiologist. Therefore, a thermogram that looks into the physiological changes in combination with numerical simulation performing 'what-if' analysis could act as an adjunct tool to mammography. RESULTS: The proposed framework suggested that it could reduce the occurrence of false-negative/positive cases. CONCLUSION: A numerical bioheat model of a female breast is developed and simulated. The results are compared with experimental results. The possibility of this method as an early detection tool is discussed.

Body Temperature↗

Liquid crystal thermography: quantitative studies of abnormalities in carpal tunnel syndrome.

We performed liquid crystal thermography (LCT) in 38 normal hands and in 23 hands with carpal tunnel syndrome (CTS) documented by nerve conduction studies (NCS). Two of the authors unaware of the clinical situation read the 2 palmar thermograms taken at a 5-minute interval. They determined the absolute temperatures of the tip of digit 1 (D1), D2, D3, D4, D5, and of the thenar and hypothenar eminences. We calculated the temperature differences (absolute values throughout) between any 2 of these 7 sites, and computed the median index (MI = [D1 - D2] + [D1 - D3] + [D2 - D3]). Comparison of the control and CTS groups revealed greater temperature differences in CTS between D1 - D3, D1 - D4, D3 - D5, D4 - D5, and MI. There was a marked overlap between the 2 groups. Comparison of individual CTS hands with controls revealed definite thermographic abnormalities in 0 of 9 hands with mild NCS abnormalities, and in 7 of 14 hands with marked NCS abnormalities. These findings indicate that the sensitivity of LCT in CTS is low compared with NCS, and previous favorable reports concerning thermography in CTS may have been due to lack of control series or absence of quantitation.

Adult↗

The use of infrared thermography in the evaluation of oral lesions.

This study was conducted to quantitate the degree of inflammation associated with oral lesions by using infrared thermography. It was reasoned that the increased vascularity associated with inflamed tissue may result in measurable increases in surface temperature. One subject with normal oral mucosa and three subjects with oral lesions of varying causes were studied with a thermal video system, using an infrared imager and microprocessor. A clinical photograph of each subject was obtained. Multiple thermograms were made in a temperature range of 30.0 C to 34.2 C at a sensitivity of 0.2 C. Photographs were taken on different occasions to determine whether the temperature readings could be duplicated and to test the accuracy of each reading. The normal surface temperature of the control subject's mucosa was significantly cooler than were the temperatures of the inflamed areas in the subjects with lesions induced by chemotherapy. The temperature of the areas of stomatitis was consistent (subject 3, mean = 33.7 C; subject 4, mean = 33.9 C). The necrotic center of a traumatic ulcer inhibited measurement of an underlying inflamed base and, thus, was equivalent to the control in temperature (subject 1 (control), mean = 31.9 C; subject 2 (necrotic lesion), mean = 31.7 C). These results suggest that infrared thermography may provide a means to quantitatively assess the degree of mucosal inflammation.

Adult↗

Relationship of scrotal surface temperature measured by infrared thermography to subcutaneous and deep testicular temperature in the ram.

The right testis of 9 anaesthetized rams was removed from the parietal tunica vaginalis and replaced by a surrogate testis (water-filled balloon) through which water of known temperature was circulated. Thermistors were inserted in the surrogate testis, between the scrotal skin and parietal tunica vaginalis on the right side, and deep within the intact left testis. Scrotal surface temperatures over the surrogate and intact testes were measured by infrared thermography. Scrotal surface temperature was correlated (P less than 0.01) with both subcutaneous (r = 0.95) and surrogate (r = 0.91) testicular temperature. The temperature differential between scrotal surface (30.1 +/- 0.1 degrees C) and deep testicular temperature over the intact side (34.9 +/- 0.09 degrees C) was 4.8 degrees C at an ambient temperature between 24.0 and 26.6 degrees C. Contact with the scrotal skin is not required to measure scrotal surface temperature by infrared thermography. This, coupled with the close association between scrotal surface temperature and that of underlying structures, will enhance our ability to understand better testicular temperature regulation and scrotal/testicular function.

Animals↗

Infrared thermography of bullfrog skeletal muscle at rest and during an isometric tetanus.

Heat production in skeletal muscle has been studied with a thermopile consisting of several thermocouples in contact with muscle surface, and the experimental results have been interpreted on the assumption that heat is produced in a uniform manner. In the present study we have examined the temperature distribution of bullfrog sartorius muscle by the technique of infrared thermography, in which muscle temperatures at various regions can be measured and displayed as a thermogram on the monitor screen without thermal contact. It was found that in the muscle at rest and during an isometric tetanus, the temperature was not uniform, but differed from region to region. The amount of heat production during an isometric tetanus also differed from region to region, but the time course of heat production was nearly uniform in every region. By putting position markers on the muscle surface, it was possible to record muscle segment length changes together with temperature changes. It was found that during an isometric tetanus, the tibial region was stretched by the other regions, and the amount of heat produced was significantly greater in the other regions than in the tibial region. The application of infrared thermography in muscle energetics studies seems promising if the sensitivity of infrared detectors is improved.

Animals↗

Thermography in deep venous thrombosis of the leg.

Thermography, a fast, simple, and sensitive method, was compared with conventional contrast medium phlebography in the diagnosis of acute deep venous thrombosis of the lower extremities in 141 patients. In 84% of the cases, the results with both techniques agreed. Thermograms showed the pathologic findings in 38 of 41 cases with deep thrombosis. In the three cases with false-negative findings, only the anterior surfaces of the legs were studied. In 19 cases, pathologic thermograms were recorded in the absence of deep thrombosis; the main reasons for findings were posttraumatic, postoperative, and postthrombotic states, and insufficiency of the perforant veins. If a patient has no previous history of a venous or other intervening disease, thermography with a negative finding excludes deep venous thrombosis. If it is used as a primary method, it can replace many phlebographies in the diagnosis of acute deep venous thrombosis.

Adult↗

Electronic infrared thermography as a method of assessing herpes labialis infection.

The purpose of this study was to ascertain the applicability of infrared thermography to study the natural history of herpes labialis lesions. Since thermography is capable of detecting changes not visible to the naked eye, then it may be of value in complementing clinical examination of the various stages of herpes labialis. In addition, thermographic imaging is quantitative and therefore allows for an accurate assessment of temperature changes accompanying the disease process, both within patients and between patients. Ten female patients suffering from herpes labialis were studies (mean age 25 +/- 5 years). In all cases herpes simplex virus Type 1 was isolated by the HEP-2 technique. No treatment was instituted and patients were clinically assessed and thermographically imaged daily from the prodromal phase through to resolution. A marked temperature increase (1 degree C minimum) was observed within hours of the prodromal phase and maintained until day 4. As the lesions progressed to vesicle formation, the central area of the vesicle was noted to be cooler due to the insulating effect of the fluid. Even by day 6 a significant 0.5 degree C temperature increase over background was present at the involved site and this returned to normal within 8 to 10 days. The area of thermographic involvement was three to four times larger than the clinical area of involvement (60-100 mm2 versus 20-25 mm2). To assess reproducibility, we also studied patients through two additional untreated herpes labialis episodes. The prodromal phase was reproducible thermographically and characterized by a temperature increase of 1.42 degrees C +/- 0.2 degrees C. Thermographic imaging may represent a new approach to quantifying disease activity in herpes labialis, particularly in the subclinical prodromal stage.

Adult↗

Relationship between mean body surface temperature measured by use of infrared thermography and ambient temperature in clinically normal pigs and pigs inoculated with Actinobacillus pleuropneumoniae.

OBJECTIVE: To determine the relationship between ambient temperature and mean body surface temperature (MBST) measured by use of infrared thermography (IRT) and to evaluate the ability of IRT to detect febrile responses in pigs following inoculation with Actinobacillus pleuropneumoniae. ANIMALS: 28 crossbred barrows. PROCEDURES: Pigs (n = 4) were subjected to ambient temperatures ranging from 10 to 32 C in an environmental chamber. Infrared thermographs were obtained, and regression analysis was used to determine the relationship between ambient temperature and MBST. The remaining pigs were assigned to groups in an unbalanced randomized complete block design (6 A pleuropneumoniae-inoculated febrile pigs [increase in rectal temperature > or = 1.67 C], 6 A pleuropneumoniae-inoculated nonfebrile pigs [increase in rectal temperature < 1.67 C], and 12 noninoculated pigs). Infrared thermographs and rectal temperatures were obtained for the period from 2 hours before to 18 hours after inoculation, and results were analyzed by use of repeated-measures ANOVA. RESULTS: A significant linear relationship was observed between ambient temperature and MBST (slope, 0.40 C). For inoculated febrile pigs, a treatment X method interaction was evident for rectal temperature and MBST, whereas inoculated nonfebrile pigs only had increased rectal temperatures, compared with noninoculated pigs. A method X time interaction resulted from the longer interval after inoculation until detection of an increase in MBST by use of IRT. CONCLUSIONS AND CLINICAL RELEVANCE: Infrared thermography can be adjusted to account for ambient temperature and used to detect changes in MBST and radiant heat production attributable to a febrile response in pigs.

Actinobacillus Infections↗