[Standardization of bone tissue densitometry].

Traditional X-ray technique have proved be scarcely reliable in determining bone tissue mineral status especially when comparing X-rays made at different times. The use of ergal or hydroxylapatite samples has been put forward to resolve this problem since, when used together with computerised imaging techniques, they allow a more precise and quantitative analysis to be made. The velidity of tyhis technique is confirmed by an experimental trial on animal bone.

[The application of fractal technics for the enhancement of radiographic images].

This paper deals with digital radiological image processing, with a special emphasis on quantitative measurement extraction aimed at discriminating different lung pathologies. Texture analysis of these images, not easily performed by the human eye, can be carried out by means of fractal techniques, which allow different textures to be characterized by a single parameter--i.e.

[Digital radiography].

The reliability of radiographical information may be improved by a) standardised radiography (exposure-development); b) transformation of the original image into a densitometric image and equalization with a reference wedge made of Ergal. The linear absorption coefficient of Ergal in terms of photon X energy is almost identical to the average coefficient of the bone mineral matrix; c) processing the densitometric image for additional information. An automatic image analyser controlled by a computer is used.

[Radiologist-pattern interaction in the processing of fluoroscopic images].

The great complexity of interactions among radiologist, patient and radiological apparatus, when performing radiological tests, is perhaps the main cause of difficulties in the development of automatic systems, both for classification and quantification of radiological images, and for documentation and retrieval of radiological images. The result of such interactions is not a "plate", but a diagnosis, very often the "plate" does not even coincide with the radiological investigation, if this term implies a linkage with the perceptual mechanisms of the radiologist. In other words, the "plate" provides the radiologist with the elements to achieve an interpretation of the image, which will then lead to the diagnosis.

[The role of digital storage in radiological studies based on fluoroscopic technics].

In recording radiological images obtained by fluoroscopic techniques on permanent support, digital storage, when compared with other methods, shows several interesting features, especially in order to reduce the X-ray dose and to allow for using economical hard copies. In the paper a system is described, for which it is possible to predict competitive cost in the near future; such system is based on a 512 X 512 X 6 bits digital memory, continuosly refreshed and on a software package oriented to handle radiological images. Examples of images referring to typical body segments (stomach, skull, chest) are reported.