Bibliotheca radiologica最新文献

The common factor in most of the rheumatic diseases is an arthritis. Radiometry and thermography have been shown to indicate and measure heat resulting from localised inflammation. In rheumatoid arthritis, juvenile arthritis, osteoarthrosis, gout and ankylosing spondylitis abnormal heat distribution has been recorded over affected joints. Experimental evidence has shown that temperature change reflects the inflammatory state of the joint, and that this may be used to measure the effect of therapy by oral, systemic and local drug therapy, and also surgery, i.e. synovectomy.

Considering the main objectives of thermographic techniques and the particular characteristics of passive infrared detection, the essential arguments in favor of single detector scanners have been pointed out after a brief discussion of the detection and image pickup methods when quantitative and precise (0.1 degrees C) information on the temperature distribution near ambient temperature must be obtained. Single detector scanners can have sufficiently good performance to reach the objectives of precise thermography, but their real technical limits must be well-known in practice; consequently, the thermograph performance must be clearly defined by means of the modulation transfer function, the intrinsic thermal resolution and the response uniformity, as we indicate in the second part of this paper.

General and local abnormalities of thermic distribution in the affected limb were related to some basic patterns. Hyperthermic pattern, localized or general: it depends on existence of collateral pathways (when main arterial branches are occluded). Hypothermic pattern, localized or general: it depends on existence of severe arterial stenosis with blood flow decrease.

The gradient layer direct calorimeter built in Lausanne allows proportionate measurement of respiratory and cutaneous heat losses. The latter consists of evaporative and convective plus radiative heat losses, which are separately measured. Obese subjects had lower heat losses and higher thermal body insulation than controls. The decreased heat loss may contribute to their positive energy balance by decreasing the energy cost of maintaining body temperature during cold exposure. The changes in heat loss during exercise are also illustrated.

While carrying out 10,000 breast thermographic studies we have examined 4,000 palpable lesions, 1,100 of which were verified cancers. The study of these cases according to our classification into 5 categories has shown that: (1) in the benign lesions, there were 18% equivocal results and 13% 'false positives', and (2) in the malignant diseases, there were 18% doubtful thermograms, 8.5% 'false negatives' and 10% 'false positives'. Thermography allowed us to detect 10 subclinical and 56 occult cancers; in another connection we have identified a growth phase in 11% of our cancers (fast-growth forms).

Vasomotor tests have a great diagnostic interest in many dermatologic diseases. Histamine dihydrochloride and acetylcholine chloride in intradermal injections, a rubefacient derived from nicotinic acid in epicutaneous application, and the dermograph are commonly used and studied here. There remain many unknown and controversial factors in the interpretation of the mechanisms of the drugs used for these tests. A thermographic approach using infrared thermography and the most recent technique with liquid crystals in sheet provide a new contribution to studies on vasomotor tests; these methods have contributed to the study of the vasomotor reactions observed in different dermatological affections, in particular atopic eczema, and have introduced new data in the controversy which subsists about interpretations of 'delayed cholinergic blanch'.