Multi-Mode X-ray Imaging System with One-Sided CT Capability.

摘要

The goal of this project is to develop an X-ray imaging system with three operating modes, including (1) a CT Mode with an open one-sided geometry providing complete or partial CT type image slices with arbitrary orientations and shapes, (2) a Transmission Mode providing conventional transmission images, and (3) a Fluoroscopy Mode providing real-time images. Because this Versatile, open system offers immediate access to wounded soldiers with one third the weight and cost of conventional CT systems, it is especially suitable for combat casualty care. This Phase I program was carded out with a simplified one-sided CT system which can provide tomographic images with X-rays backscattered from different body volume elements penetrated by the X-ray beam. The X-ray image sensor consists of an array of low efficiency plastic scintillation detectors which select and count the scattered X-rays providing the image signal. With spatial resolution indicators used as test objects, the X-ray exposures and the digital outputs of the X-ray detectors were measured to determine the signal-tonoise ratios, the spatial resolutions, and the minimum required X-ray exposures. The results show that with the use of high efficiency detectors, this one-sided CT system is capable of obtaining spatial resolutions from 2 to 5 Line Pairs per cm with an average patient dose per slice of less than 2 rads per image slice, or a spatial resolution greater than 7 Line Pairs per cm with an average patient dose of 5 rads per slice, which is the dose requirements for present CT systems. ....Tomography, Backscattered x-rays, Multi-mode, One-sided CT, X-ray slot camera, Digital radiography, RAD II, SBIR.