ABSTRACT

Tissue substitutes or phantom materials play an important role in diagnostic X-ray imaging. During the developmental stages of an imaging system or an imaging technique, these tissue substitute materials play an important role in evaluating the feasibility and potential to achieve the targeted imaging performance. Upon development of the imaging system or the imaging technique, they are of great use in optimizing the performance of the imaging system or refining the imaging technique. Once the developed imaging system and the imaging technique are clinically translated, the use of phantoms comprising these tissue substitutes plays an important and ubiquitous role during quality control surveys and audits to verify and ensure that the imaging system is performing as per prescribed standards. In addition to the role of tissue substitutes for qualitatively and quantitatively characterizing imaging quality, they also play an important role for radiation dosimetry. This was recognized during the early 1900s. While early work was more focused on quantifying the output from the X-ray tube, such as the milliampere meter and beam quality measurements using Béclècre's spintermeter, Belot's penetrometer, and Benoist's radiochrometer, photochromic methods were developed such as the Kienböck quantimeter where a film strip placed on the exposed region is compared 1108to a reference scale purportedly graded in units of skin epilation dose. A review of these early works is provided by various authors (Kassabian 1907, Keogh 1918).