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Perfusion CT: a worthwhile enhancement?

In 1979, just 8 years after Godfrey Hounsfield’s introduction of CT, Leon Axel first proposed a method for determining tissue perfusion from dynamic contrast enhanced CT data [1]. Due to the requirement for rapid image acquisition and processing, CT perfusion measurements through the 1980s were largely confined to research studies of renal or myocardial blood flow using electron beam CT systems [2, 3]. However, the advent of spiral CT systems in the 1990s enabled perfusion CT to be performed with conventional CT systems, thereby broadening the technique’s availability [4, 5]. The development of multislice CT systems has stimulated further interest by potentially advancing perfusion CT from a single-slice technique to a volume-based examination. More recently, clinical use of CT perfusion imaging has been facilitated by the release of commercial software packages from a range of CT manufacturers. This article aims to review the clinical applications of perfusion CT, discuss the theoretical basis, validation and operation of available software packages and to highlight likely future developments.