[Standardization of bone tissue densitometry]. / Contributo alla standardizzazione della densitometria del tessuto osseo.

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]. / Applicazione di tecniche frattali per la discriminazione di immagini radiografiche.

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. the fractal dimension. To extract the fractal dimension of an image, the so-called "blanket" method is employed, which allows the average fractal dimension of an image area to be evaluated. The result of this processing is a new image whose points are assigned the average fractal dimension value of the area they belong to. The behaviors of fractal dimension histograms related to various simulations of lung pathologies are notably different, which allows such pathologies to be effectively characterized and differentiated on a quantitative basis. The radiographic images the "blanket" method was applied to are related to simulations of both pathological and healthy tissues. The behaviors of fractal dimension histograms and the average fractal dimension values allow the characterization of the different pathologies both for single tissues and in case of superimposition of a healthy tissue on a pathological one. The promising simulation results have encouraged us to carry out the present experimental investigation in the field of lung neoplasms.

[Digital radiography]. / Radiografia digitale.

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. The first osteological results showing the correspondence between the densitometric measurements provided by the analyser and the actual bone mineral content revealed by chemical analysis are presented.

[Radiologist-pattern interaction in the processing of fluoroscopic images]. / Interazione radiologo-pattern nell'elaborazione di immagini fluoroscopiche.

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. In view of a foreseeable spreading of economical medical informatics methodologies, an aim of the present work is stressing the importance of the interactions between medical operators and information processing systems, to select relevant parameters for diagnosis. Sequences of images (originally taken by a movie camera) are presented, which relate to the motor activity of digestive apparatus segments. Processing stresses some of their morpho-dynamic features.

[The role of digital storage in radiological studies based on fluoroscopic technics]. / Ruolo della memorizzazione digitale nelle indagini radiologiche basate su tecniche fluoroscopiche.

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.