Reduced dose and improved image quality with computerized line-scan radiography system

This paper reports on Diode-Array Digital Radiography (DADR) that reduces patient x-ray dose and improves diagnostic quality compared with conventional filmed radiography. DADR geometrically eliminates scattered x-rays by using a line-scanning technique, removing background fog. The x-ray tube is collimated to produce a fan beam of x-rays which impinges on a linear detector. The source and detector are held in alignment by a C-arm which scans the patient by translating the assembly orthogonally to the detector aperture. Each image line is exposed for a very brief time, which provides for a very short effective x-ray exposure and eliminates blurring due to patient motion. The detector uses a patented combination of scintillator, fiber optic image guides and self-scanning photodiode arrays which, in combination with scatter rejection, creates an electronic image having greater dynamic range than filmed x-rays. The image is converted to 12-bit digital computer data which may be sorted inexpensively, enhanced for diagnosis, and transferred to a PACS network. Images are displayed in full 2352 x 2000 resolution on a high-bandwidth monitor. Diagnostic experiments have concentrated on chest imaging, an application for which Scantech is developing a new product. Patient dose is typically less than half that incurred with conventional techniques