A Word About Radiation Dose

Abstract

The development of computed tomography (CT) colonography (CTC) as a viable clinical tool has paralleled the rapid advancement of CT technology. About one decade after CT was revolutionized by the advent of spiral/helical CT technology, multislice CT (MDCT) was introduced, offering better longitudinal and temporal resolution. These benefits improve nearly all imaging applications in which broad anatomic coverage is required in a breath hold, including CTC. Although dual or split detector systems have been available since the early 1990s, CT scanners with four data channels were introduced in 1998 and have provided another quantum leap in CT performance, permitting thinner slices, shorter scans, and greater volume coverage. Now, systems with 8 to 16 data channels are emerging, and manufacturers are testing incorporation of flat-panel detectors in CT scanners as a future means of extending this technology to nearly instantaneous CT data acquisition. However, the potential for increased radiation exposure with MDCT has dampened enthusiasm for its use, in particular in screening applications such as CTC.