The definition of advanced CT changes yearly. In 2001, Diagnostic Imaging editors had a challenge finding a group of authors experienced with four-row CT. By 2002, the exponential leap to 16-row posed the same problem. This year, finally, many imaging centers worldwide have been testing the limits of their 16-row scanners and determining the limits of this newest generation of technology. The gap between "advanced" and "everyday" is rapidly disappearing.

Such new capabilities, particularly cardiovascular applications that are proving to be more accurate than angiography, have fueled rapid CT procedure growth. Procedures once performed with radiography, or not at all, have become mainstream.

The next revolutions in CT may be more subtle. Software that automates the useful but tedious process of creating custom 3D reconstructions may be the first. Meanwhile, manufacturers are already planning another exponential leap in detectors-to 64, 128, or 256 rows-as well as CT units specially calibrated to cardiovascular imaging or radiotherapy planning.

That next generation of scanners is still a few years away, which means that for the first time in a number of years, CT imagers have the luxury of knowing that the leading edge of technology is more or less within sight.