Thermographic Studies Research Articles

Thermographic studies of phantom and canine kidneys thawed by microwave radiation

Thermographic studies of phantom and canine kidneys thawed by microwave radiation

Thermography in the detection of carpal tunnel syndrome and other compressive neuropathies

Studies were conducted using liquid crystal thermography (FlexiTherm) and electronic thermography for the diagnosis of carpal tunnel syndrome. Studies were also conducted to differentiate carpal tunnel syndrome from peripheral neurovascular injuries. Ninety patients were included in the study, with an average follow-up time of 24 months. Fifty patients also had electric studies for comparison and contrast. Thermal patterns of carpal tunnel syndrome showed a decreased vascular heat emission pattern over the median nerve distribution. The procedures using thermography consisted of imaging of the cervical spine, shoulders, forearms, and hands by Wexlerian guidelines to obtain diagnostic thermograms and a stress series. Results of the studies showed that thermographic studies were efficacious and sensitive for the differential diagnosis of carpal tunnel syndrome from other peripheral compressive neuropathies, including cervical radiculitis, thoracic outlet syndrome, cubital tunnel syndrome, and Guyon's canal syndrome. Biomechanic and etiologic factors indict carpal tunnel syndrome to be an occupational disease. Thermographic technique use may lead to the early diagnosis, treatment, and preventative measures that could eliminate the high cost of manpower loss and of medical care often concomitant with carpal tunnel syndrome.

Thermography in posttraumatic pain.

Posttraumatic pain is often associated with complex disturbances of the sympathetic nervous system which also controls microcirculation of the skin. Circulatory skin changes are in turn reflected by altered superficial thermal emission, which can be reliably imaged by thermography. Examples of classic thermographic patterns associated with commonly occurring injuries and detected along cutaneous distributions of peripheral nerves or spinal root dermatomes are presented. Thermographic abnormalities may also occur in ondermatomal distributions to involve an entire hand, foot, or extremity as observed in reflex sympathetic dystrophy. Such thermographic findings often appear before skin or roentgenographic changes become manifest and lead to earlier diagnosis. Prompt and more effective treatment, particularly in reflex sympathetic dystrophy, may thereby be initiated so that full blown, difficult to manage, chronic disability may be averted. The diagnosis of malingering may also be strengthened or suspected if thermographic studies together with other examinations are normal.

A thermographic studies on the relationships between the nasal skin temperature and nasal airway resistance

A thermographic studies on the relationships between the nasal skin temperature and nasal airway resistance

Synthesis of solid solutions of perovskites

The authors carry out thermographic studies, using a derivatograph, in order to understand the nature of the processes taking place during the synthesis of solid solutions of perovskites. Based on the detailed studies on the phase transformations occurring in the charges of the PSN-PMN solid solutions and on the selection of the optimum conditions for carrying out their synthesis, the authors obtained a powder containing a minimum quantity of the undesirable pyrochlore phase and by sintering it using the hot pressing method, they produced single phase ceramic specimens containing the perovskite phase alone with a density close to the theoretical value and showing zero apparent porosity and water absorption.

Breast thermography.

This discussion of breast thermography reviews the following: techniques; the "normal" thermogram found in approximately 65% of gynecologic patients; analysis and classification of a thermogram; factors influencing thermograms (breast symmetry, breast size, age, parity, history of breast feeding, menstrual cycle, pregnancy and lactation, exogenous steroid therapy, menopause and danazol, family history of breast carcinoma, benign breast disease, and time; thermograms and breast carcinoma; and clinical considerations. The temperature and the vascularization of the breast, which are modified by endocrine, inflammatory, and tumoral influences, can be studied through pictures formed by multiple simultaneous temperature in measurements called thermograms. Thermographic examinations must be performed in a draft-free, temperature, and humidity controlled room, where a constant temperature 20 degrees C is maintained. Using telethermography, a front and right and left oblique views must be taken. For contact thermographic studies, the cholesterol plate or sheet on which color distribution corresponds the best to the patient's mean temperature should be selected and a front and an oblique view should be taken of each breast. Thermograms must be analyzed by noting anatomic and vascular symmetry, by measuring temperature differences between comparable areas of the 2 breasts, and by observing the normal round contour of the breast. In addition, repeat thermograms must be compared to previous studies and any observed change must be noted. Increased heat can be vascular, focal, or diffuse. Recent reports and opinions on relationships between abnormal thermograms and cancer are controversial. The most favorable reports on the value of thermograms in the identification and management of breast cancers originate from the University of Strasbourg and the Cancer Institute of Marseille. It is the belief of this physician that thermography is not a specific test for carcinoma detection, for the diagnosis of any other breast disease. It is, however, a sensitive marker of local thermal and vascular abnormalities, which can be helpful in focusing attention on specific patients and for research. The greatest interest of clinical thermography lies in its use in the detection of carcinoma. Patients who have an abnormal thermogram need thorough clinical evaluation. It is possible that the greatest potential application of thermography is in its use in comparison studies.

Delayed Primary Closure. Blood-Flow in Healing Rat Skin Incisions

In an earlier study delayed primary closure (DPC) wounds were shown to develop higher biomechanical strength than primary closure (PC) wounds. In order to elucidate the underlying mechanism, local clearance of 133Xenon and thermography studies were undertaken. A paired comparison design with deposits of 133Xenon injected in the wound margins 3 and 4 days postoperatively, and directly into the wound tissue 10, 20 and 60 days postoperatively was used. Very pronounced differences, with higher blood-flows for DPC wounds, were found in the early measurements. In the later measurements there were significant but less obvious differences. With thermography no differences could be detected. It is concluded that DPC wound have a higher blood-flow, especially in the initial wound healing phase. This supports the hypothesis that an increased blood-flowing during early wound healing is beneficial for the development of mechanical strength in the maturing normal scar.

Millimeter-Wave Thermography Preliminary Clinical Findings in Head and Neck Diseases*

AbstractMillimeter wave thermographic studies of neck and head diseases are reported; they yield more diagnostic information about subcutaneous and even intracranial thermal abnormalities than conventional infrared thermography which is limited to cutaneous temperature measurements.

Millimeter-wave Thermography — Application to Breast Cancer*

Thermographic studies of 14 patients with breast carcinoma were performed using two millimeter wave scanners for 30 and 68 GHz. Small correlation with infrared thermograms was observed indicating the depth sensing capabilities of millimeter waves. Correlation with mammographic and other clinical findings was good for tumors with medium subcutaneous depth. These preliminary results indicate a need for a statistically more significant number of cases, extension towards lower sensing frequencies and experiments on postoperative specimens and phantom models.

A System for Developing Microwave-Induced Hyperthermia in Small Animals

A system has been developed at the University of California, San Francisco, for producing microwave-induced hyperthermia in small laboratory animals by irradiating an entire transverse section of defined height, for the purpose of assessing the effects of heat alone and heat plus ionizing radiation on normal tissue and tumors. A thermometry system consisting of a thermistor array, a low-voltage scanner, and a single channel recorder is described. Thermographic studies on sacrificed animals and thermistor studies in a phantom reveal a pattern of deep heating in a well-defined region, corroborated by thermistor measurements in vivo. Long-term animal survival at elevated temperatures (/spl equiv/45/spl deg/C) throughout a large volume is not readily obtained. Seven out of 17 animals heated to 44.8/spl deg/C throughout the entire abdominal region survived seven days post-heating, and histologic findings on this group of animals are briefly described. Various aspects of the biological techniques and the endpoints for current and planned experiments are discussed.

Thermographic studies of phantom and canine kidneys thawed by microwave radiation

Thermographic studies of phantom and canine kidneys thawed by microwave radiation

Thermographic and Behavioral Studies of Rats in the Near Field of 918-MHz Radiations

Patterns of thermalized energy of rat carcasses exposed to 918-MHz CW radiation in the near zone have been determined using a computerized thermograph. Peak absorption of energy in the body was estimated to be 0.9 W/kg per mW/cm/sup 2/ of incident energy. Operant responses of irradiated rats to schedules of fixed-ratio (food) reinforcement under the same conditions as the dosimetric test were observed to occur at averaged power densities of 30-40 mW/cm/sup 2/. This range of densities corresponds to absorbed peaks of energy of 27-36 W/kg. No change in behavior was observed for incident power densities and peaks of absorbed energy to 20-30 mW/cm/sup 2/ and to 18-27 W/kg, respectively, and all changes at higher values were reversible.

The relationship of mammary temperature to parturition in human subjects

Four hundred and seventy thermography studies were performed on 210 women to measure mammary temperature prior to, during, and immediately following pregnancy. Mean mammary temperature of 33.3 ± 0.1° C. (S.E.M.) obtained in 14 nonpregnant patients increased to 34.2 ± 0.1° C. (S.E.M.) by nine weeks of gestation (p < 0.01). The difference between mammary and sternal temperature was negative in the nonpregnant state and became positive after 18 weeks of pregnancy. Mammary temperature remained significantly higher in the pregnant group than in the nonpregnant group (p< 0.001) up to term. In six postpartum patients, a further increase from prepartum values to 35.4 ± 0.6°C. (S.E.M.) occurred. The results suggest that relatively large changes in mammary blood flow and/or metabolic rate take place in human subjects in early pregnancy and on the day following parturition.

Determination of power absorption in man exposed to high frequency electromagnetic fields by thermographic measurements on scale models.

When the body of man, small compared to a wavelength, is exposed to high frequency (HF) electromagnetic (EM) fields, the absorbed power density patterns and total absorbed power may be approximated by the simple superposition of the internal electric fields obtained from the quasistatic coupling characteristics of the electric and magnetic field components determined independently. These characteristics were obtained for full scale man by thermographic studies of power absorption in scale models of man exposed to fields at frequencies scaled up inversely proportional to the model size. A VHF resonant cavity was used to provide the necessary field strengths for producing measurable power absorption patterns under simulated HF exposure conditions. The results indicate that peak power absorption densities as high as 5.63 W/kg can be produced in man exposed to 10 mW/cm <R xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</R> 31 MHz radiation fields. The results show that the absorption decreases as the square of the frequency as predicted by theory for frequencies below 31 MHz.

Thermographic studies of serpentines by ignition up to 1400° C

(1974). Thermographic studies of serpentines by ignition up to 1400° C. International Geology Review: Vol. 16, No. 2, pp. 202-213.

Thermographic studies on the healing of differently tied fascial sutures

Thermographic studies on the healing of differently tied fascial sutures

Early flow in the implanted internal mammary artery in the dog. Arteriographic and thermographic studies of the implant.

Early flow in the implanted internal mammary artery in the dog. Arteriographic and thermographic studies of the implant.

Relation between the desiccation rate and the body temperature in thermographic studies

An equation has been derived and experimentally verified for calculating the evaporation rate from a known thermogram, or vice versa, taken under conditions of thermographic testing.

Thermographic response to local external heat sources.

HomeRadiologyVol. 102, No. 2 PreviousNext Diagnostic RadiologyThermographic Response to Local External Heat SourcesJoAnn D. Haberman, John E. Francis, Tom J. LoveJoAnn D. Haberman, John E. Francis, Tom J. LoveAuthor Affiliations Department of Radiology University of Oklahoma Medical CenterOklahoma City, Okla. 73104JoAnn D. HabermanJohn E. FrancisTom J. LovePublished Online:Feb 1 1972https://doi.org/10.1148/102.2.341MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In AbstractA mathematical model for predicting skin temperatures during thermography is related to temperatures observed during actual thermographic studies. Both normal and abnormal patterns were studied; the abnormal patterns resulted from the application of an external heat source which simulated an internal lesion. Variations of thermal response were noted, and the increased heat loss from the local area was compared to the metered heat input from the probe. The results given by the model were in agreement with observed temperatures. The role of the veins in the thermoregulation of temperature elevations in simulated lesions is demonstrated.Article HistoryPublished in print: Feb 1972 FiguresReferencesRelatedDetailsCited ByPhysics in Medicine and Biology, Vol. 33, No. 8Oral Surgery, Oral Medicine, Oral Pathology, Vol. 56, No. 3IEEE Transactions on Biomedical Engineering, Vol. BME-24, No. 4Physics in Medicine and Biology, Vol. 20, No. 2Physics in Medicine and Biology, Vol. 20, No. 3Recommended Articles RSNA Education Exhibits RSNA Case Collection Vol. 102, No. 2 Metrics Altmetric Score PDF download

Thermographic studies of human skin subjected to localized pressure.

1. A series of thermographic studies were made over various body surfaces that consisted of determining the thermal fluctuation of the body surface subjected to localized pressure.2. A positive correlation between temperature variation and localized pressure was found.3. Variations of temperature of the body surfaces are described and discussed.4. It is suggested that the thermographic instrument may become a useful tool in the fitting of prosthetic devices where localized pressure may be a factor in a misfitting prosthesis.