The relationship of computed tomography and ultrasonography in diagnosis of abdominal disease.

A detailed comparison of computed tomography and ultrasonography of the abdomen is presented from a theoretical point of view. The advantages and limitations of both modalities are discussed in terms of scan content, resolution, plane of interrogation, dynamic imaging, examination time, imaging problems, automation, contrast administration, puncture guidance, examination availability, hazards, personnel and space requirements, and cost. Analysis of these factors leads the authors to conclude that ultrasound should be the procedure of choice for sectional imaging of the abdomen. Computed tomography should be reserved for those situations in which the ultrasound examination is not diagnostic (i.e., skeletal system, lungs, mediastinum).