Bibliotheca radiologica最新文献

A discussion has been given of the principles and techniques of microwave thermography. The method is analogous to infrared thermography in that it detects thermal radiation emitted by the body. It differs in that it is sensitive to temperatures several centimeters beneath the skin surface and has coarser spatial resolution. Results are shown of successful attempts to detect subsurface thermal gradients in feline and human tissue. Planned clinical evaluation is described.

Statistical analysis of approximately 800 cases of breast cancer followed up for at least 3-5 years with careful correlation between mammography, thermography and clinical data has confirmed the accuracy and indispensable use of thermography for prognosis and follow-up. Pre-therapeutic prognosis. Strong correlations exist between the thermographic class and survival for T1, T2 and T3 cancers, confirming the contribution of thermography in therapeutic decision. Thus, a T1 cancer should be treated differently depending on the thermographic findings. Post-irradiation follow-up. Correlations exist between the development of thermic anomalies and the effect of irradiation on the cancer, showing the possibility of confirming sterilization or early detection of a recurrence. This is valid only if the thermic effects of radiation on the skin and gland are recognized and discounted.

In 27 post-menopausal patients with soft-tissue lesions of advanced breast cancer, temperature changes in skin-over tumour have been evaluated for their ability to predict response to additive hormone therapy. The thermoprofile across the tumour and its bed was selected for measuring purposes in preference to other thermographic methods. Serial measurements were carried out before and during therapy, and the observations correlated with the clinical response to therapy. Of the 14 patients who showed decrease of at least 1 degree C in the thermoprofile peak value within 2 weeks of initiating hormonal therapy, 57% showed clinical evidence of tumour regression 3 months later. Of 13 patients who did not show this change, none showed tumour regression later.

Thermography in veterinary medicine has hitherto been proven to be a method of great value in the detection of orthopaedic lesions in racehorses. Lesions of the musculo-skeletal system affecting tendons, joints, bones and skeletal muscle can be demonstrated and documented at an early stage thereby preventing the development of more serious lesions.

All techniques for measuring thermal blood flow have in common a small heat source and two temperature difference sensors placed in or on the tissue. The measured temperature difference can be quasistationary, nonstationary or constant, depending upon the heating pattern. Its extent and course, respectively the heating output in the case of pulse fluvography, are dependent upon blood flow. Conversion of the heat transport coefficient into specific blood flow is possible only if the vessels in the temperature field are predominantly capillaries. Both the sink and the pore theory make it possible to draw conclusions about specific blood flow from the measurement values obtained.

Unlabelled: Reference was made to a series of 35 cases of malignant melanoma which had not been operated on, and contributions of thermography in the following were taken into consideration. 1.

Diagnosis: the complementary nature of clinical, thermographic and histological information, both for the tumour and the lymph nodes; differentiation between less thermogenic malignant melanomas (Dubreuilh melanosis, LMM and SSM) and the forms giving rise to extensive and intense hyperthermy (NM). 2.

Prognosis: proposal of a prognostical classification which permits the evaluation of malignancy and, to a certain degree, the prediction of survival in a manner which is more significant than the histo-topographical classification. 3.

Follow-up: detection of local recurrences and/or lymph-node metastases in an infra-clinical state.

A very simplified 2-dimensional simulation model of the skin and subcutaneous tissues is presented. The model is given in an annotated FORTRAN computer program with suggested numerical values for all the required constants. The model can be used to evaluate surface temperature gradients and subcutaneous thermal gradients which result from deviations of subcutaneous blood flow or heat production.

Temperature in man measured or recorded by different means, is not constant but varies in a predictable and rhythmic fashion. Circadian (about 24-hour) rhythms have been demonstrated and studied in healthy men and women as well as in patients under a wide variety of experimental conditions and diseases. With the help of special computer programs (Halberg's cosinor) inferential statistical analyses can be performed. There validate and characterize a biological rhythm (i.e., core temperature) by several parameters: the period (tau) the acrophase (phi) (timing of the peak), the amplitude (A) and the rhythm-adjusted mean (M). Each one of these parameters is given with its confidence limits when the studied rhythm is detectable (p less than 0.05). The human temperature (oral, rectal and skin) circadian rhythm has been validated and quantified in healthy newborns, in healthy adults on various diets (including near-fasting conditions: 220 cal/24h, casein) and various type of activities. Food intake does not appear to influence the temperature circadian rhythm. The rhythm persists with a change of period and/or acrophase during isolation underground, without time dues or clues. Its acrophase can be shifted by manipulating synchronizing factors (i.e., shift-working, transmeridian flight). Alteration of circadian temperature rhythm may result from the timed administration of certain drugs (i.e. reserpine) and from certain chronic diseases (without overt fever). A first attempt to use both thermography and chronobiological method has been made independantly by Gautherie et al [40] and Smolensky [41] in the prediction of therapeutic value of a given modality during the course of breast cancer treatment.