ABSTRACT
Since its introduction by Godfrey Hounsfield in 1971, computed tomography (CT) has largely been recognized as a powerful imaging tool for demonstrating internal anatomy. However, CT also has the ability to quantify physiological processes, as was first shown in 1980 when Axel (1) published a methodology for the determination of cerebral blood flow by rapid-sequence CT. At that time, the speed of image acquisition and data processing of conventional CT systems was too slow for the technique to become widely accepted. Thus, throughout the 1980s, use of CT to quantify physiological processes was largely confined to studies of myocardial and renal blood flow using electron-beam CT systems, restricting its application to research only (2,3). The development of faster, spiral CT systems in the 1990s enabled the development of methodologies that could measure tissue perfusion and other physiological processes on conventional CT systems that were widely available (4). Interest in this area has been stimulated further, by the introduction of multislice CT and by the release of commercial perfusion CT software from a number of major equipment manufacturers. The first reported assessment of tumor physiology by conventional spiral CT was in 1993, which was a study of hepatic perfusion, including patients with metastases (5). This chapter aims to describe the current capabilities of CT in the assessment of tumor physiology, to describe the technique’s advantages and limitations, and to identify future potential developments.
