David J. Steklenski

Comprehensive and automated image quality performance measurement of computed radiography systems

A method is developed that enables comprehensive and automatic image quality testing of storage phosphor-based computed radiography (CR) systems. The measurements made with this method are both quantitative and objective, and are consistent with the guidelines set forth by the American Association of Physics in Medicine Task Group 10. The method is implemented as a toolkit that consists of a test phantom, a procedure for making controlled x-ray exposures, and software that automatically analyzes phantom and flat-field images then compares the measured results against a set of tolerances. By using this new method, acceptance testing and periodic image quality control testing of CR systems can be performed quickly and efficiently. A complete CR test that includes measurements for three cassette sizes can be finished in about one hour.

Design and performance features of a new mammographic film/screen system

Most current research in mammographic detector development has been focused on digital detectors. However, the vast majority of clinical practice still uses film/screen systems. This paper will report on the design and performance features of a new film/screen system for mammography that has the potential to become the new gold standard in image quality for this demanding application. This new system includes a new film and new intensifying screens. The new film has unique emulsions on each side of the base. It features novel fine-grain, metal ion-doped silver halide microcrystals. It is exposed with a single intensifying screen. Two different intensifying screens have been developed to create systems with different speeds. The new screens use an improved phosphor and new coating structures. The highfrequency MTF has been boosted. The system provides higher contrast, lower noise, and sharper images.

Performance characteristics of a flexible antiscatter grid used in computed radiography

In this paper we examine the imaging performance of an experimental mechanically-flexible antiscatter grid for use with computed radiography. Bucky factors, contrast improvement factors, and signal-to-noise improvement factors were computed from transmittance measurements made with 5-, 10-, 15-, 20-, and 25-cm uniform-thickness water phantoms. These phantoms were selected to span the range of scatter fractions found in chest radiography.