SBIR-STTR Award

The development of a novel electronic screen/film cassette for use in medical x-ray imaging (radiography) is proposed. During phase I, a standard cassette will be modified by adding a two dimensional array of photodetectors interdigitated with a second array of light emitting diodes (LED's), placed behind the back intensifying screen. The photodetectors, activated during a radiographic exposure, will be used to estimate the regional x-ray exposure received over contiguous 2 - 10 cm2 regions of the film. Following the termination of the x-ray exposure, the interdigitated array of LEDs would be activated momentarily, each diode delivering an additional amount of light exposure, determined by the signal recorded by nearby photodetectors, such that the resultant optical densities recorded on a radiograph, once developed, would lie above some predetermined threshold value.Use of the proposed cassette will improve upon current radiographic film quality in three ways:1. by increasing image contrast in ordinarily underexposed regions ("toe") of a normal radiographic film;2. by compressing the range of optical densities recorded on a normal radiographic film, and;3. by reducing the "retake" rate for severely underexposed radiographs.During phase II, several preproduction prototype cassettes will be constructed using several common screen/film types and evaluated in a series of clinical tests in a variety of radiographic procedures - chest, mammographic and bone radiography.

Thesaurus Terms:
Biomedical Engineering, Instrumentation Clinically Oriented, Optics, Image Enhancement, Optics, Image Processing Analysis And Display, Optics, Imaging-Visualization, Radiodiagnosis And Radiodiagnostic Methods, Radiography Optics, Light Emission, Optics, Photomultipliers, Physical Properties, Densitometry Models, Phantom Models National Cancer Institute (NCI)

Lost image contrast in underexposed regions of x-ray films (radiographs) is a persistent and pervasive problem that compromises the reliability with which radiologists diagnose disease from radiographs. This is sometimes called the "dynamic range" limitation of film. The X-Ray Light Equalizer (XLE) is an electro-optical device that boosts the contrast of underexposed regions of any radiographic film by supplementing x-ray exposure with additional light exposure, thereby extending the dynamic range of radiographic film and improving diagnostic accuracy.During Phase I, a prototype XLE device was constructed and tested. The results of that work indicated that:(1) virtually any x-ray film can be improved using light equalization,(2) contrast improvement by factors as large as five are possible with this approach, and(3) the prototype XLE significantly increased image contrast in underexposed regions of radiographic images of chest and head phantoms without noticeably affecting the adequately exposed areas of the same films.The primary goal of this Phase II research effort is to evaluate the clinical efficacy of light equalization radiography in chest, portable, and mammographic exams. Clinical prototypes of XLE devices for each of these three areas will be developed during Phase II. Observer studies will be carried out at the University of Chicago in chest and portable radiography.Awardee's statement of the potential commercial applications of the research:The XLE will be inexpensive, selling for approximately $10,000, and easy to use. Each of the 46,000 hospital-based x-ray units in the United States is a candidate for the installation of a XLE.

Thesaurus Terms:
Biomedical Engineering, Instrumentation Clinically Oriented, Optics, Image Enhancement, Optics, Image Processing Analysis And Display, Optics, Imaging-Visualization, Radiodiagnosis And Radiodiagnostic Methods, Radiography Neoplasms Diagnosis, Breast Neoplasms Diagnosis, Mammography, Optics, Light Emission, Optics, Photomultipliers, Physical Properties, Densitometry Computer, Personal Computers, Human, Clinical, Models, Phantom Models National Cancer Institute (NCI)