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Biomedical subjects

L S Jeromin

Publications and source records attributed to L S Jeromin.

6 recordsLinked to original sources
PubMed1998

The development of a new direct digital extra-oral radiographic system prototype using a thin-film transistor panel.

OBJECTIVE: To develop a new method of direct digital image acquisition for extra-oral radiography. METHODS: A selenium detector was combined with a thin-film transistor sensor and integrated with current technology for computed radiography in a system named Direct Radiography (DR). The effective image area of the prototype is 178 mm x 213.5 mm, and consists of a 1280 x 1536 pixel matrix with a pixel pitch of 139 microns x 139 microns. The electrical characteristics were evaluated and image quality was tested with a dried human mandible and half-skull phantom. The resultant images were subjectively reviewed by seven oral and maxillofacial radiologists. RESULTS: The prototype had a signal-to-noise ratio of 400:1 when the exposure was 250 x 10(-8) C/Kg. Spatial resolution was equal to the Nyquist frequency of 3.55 cycles/mm. The images of the phantoms were considered to be of equivalent quality to conventional screen-film images and demonstrated the normal anatomical structures used for clinical evaluation. Three to four images per minute were generated with this system. CONCLUSION: The DR system has an X-ray sensitivity comparable with a 400-speed film-screen system and appears suitable for clinical radiography. Further evaluation is therefore planned.

Humans↗
PubMed1980

Xeroradiography for intraoral dental radiology. A process description.

A novel x-ray imaging system for intraoral dental radiography is described. The imaging process is based on xeroradiographic principles. The surface of a small selenium photoreceptor is electrically charged. After insertion into a light-tight cassette, the photoreceptor is placed intraorally and x-ray exposed like film. The resultant electrostatic charge image is developed in a processor using liquid toner. The toner image is then transferred from the photoreceptor and fixed to a white plastic substrate for viewing. After cleaning, the photoreceptor is available for reuse. In contrast to film images, xeroradiographic images are exposed and processed sequentially. Processing time is approximately 20 seconds. Two image characteristics--edge enhancement and deletion--are primarily responsible for many advantageous qualities of xeroradiographic images over film images. An experimental processor was tested successfully at two dental schools.

Alloys↗
PubMed1980

Xeroradiography of dental structures. IV. Image properties of a dedicated intraoral system.

Dental xeroradiography, a new imaging system designed specifically for intraoral use, provides a convenient, rapid, low-dose alternative to conventional film radiography. In this study the new imaging system was compared to conventional direct-exposure dental film technique for basic imaging characteristics of contrast, resolution, and noise. Dental xeroradiography proved to be a superior imaging system for demonstrating dental structures and did so at radiation doses one-third of those required for conventional dental (film) radiography.

Humans↗
PubMed1979

Imaging properties of intraoral dental xeroradiography.

A prototype imaging system for intraoral dental xeroradiography has been described. In vivo evaluations of image quality show that intraoral xeroradiographs are superior to conventional intraoral film radiographs primarily because of the wide latitude and edge enhancement properties of xeroradiography. In addition, intraoral xeroradiography requires only a third of the radiation dose of corresponding intraoral film techniques.

Evaluation Studies as Topic↗
PubMedDate not supplied

Dose comparisons for mammographic systems.

Dose estimates were made for Kodak Min-R screens combined with Kodak Min-R film and Kodak Ortho M film, both with and without a 5:1 Bucky grid; for standard xeroradiographic techniques in negative development mode; and for the new, higher sensitivity xeroradiographic process of the Xerox 175 System. The estimates were derived from exposure versus depth measurements in phantoms made of BR12 breast simulation material using thermoluminescent detectors. A molybdenum target source with molybdenum filtration, at a half-value layer of 0.37-mm Al, was used for the screen-film measurements. All xeroradiographic measurements were made with a tungsten target source with aluminum filtration at half-value layers of 1.5 to 1.56 mm Al. Mean glandular dose estimates for the Min-R screen/Ortho M film combination with Bucky grid and for the new xeroradiographic process were found to be similar. Dose reduction with the new xeroradiographic system was achieved through a more sensitive photoreceptor and more sensitive development, which also improved the unique imaging characteristics of xeroradiography.

Biophysical Phenomena↗