The growth in the applications of physics to medicine is perhaps best illustrated by the developments in medical imaging. When AAPM was founded, medical imaging consisted primarily of x-ray fluoroscopy (direct images) and radiography (exposures on film). Although these techniques still dominate the work of a radiology department, there are a number of new ways of making images of the interior of the living body. (See, for example, the cover of this issue and figure 1.) Many of these new imaging methods depend on computers to perform the enormous amounts of data-analysis required—computed tomography or nmr imaging, for example, would not be possible without computers—and in many other cases computers serve to provide enhanced images that may allow more accurate diagnoses.