ENERGY-SELECTIVE RADIOGRAPHY: A REVIEW.

Abstract

Energy-selective radiography makes use of body transmission measurements over multiple X-ray energy spectra. These measurements of the spectral properties of the transmitted radiation add a novel dimension to classical radiography, and provide more information than a measurement over a single arbitrary spectrum for the same radiographic exposure. The central questions are: How clinically relevant is this added information? How can measurements be combined to provide an improved image or to isolate valuable and previously unobtainable information? How can imaging systems be constructed to acquire energy-selective measurements? What are the noise properties of energy-selective images, and how do they compare to conventional images? This chapter begins with a short review of early contributions to energy selective radiography, and then describes some of the physical forms of dual-energy apparatus. A linear model of X-ray attenuation is presented. The presentation summarizes much of the analytical structure of broadband energy-selective radiography that dates from the mid-1970s.