Between 1993 and 1998, the use of sonography relative to the other cross-sectional imaging modalities decreased from 56% to 43% (p<or = 0.001). During the same time, CT use increased from 30% to 41% (p<or = 0.001), and MR imaging use increased from 14% to 16% (p<or = 0.001). Survey responses indicated that potential cost saving was not a major factor in physicians' decisions to use sonography rather than other cross-sectional imaging modalities.