We developed and tested a prototype case-based decision support system to explore the applicability of this technique to the selection of diagnostic imaging procedures. We developed a case-based system, named ProtoISIS, based on the Protos learning apprentice. ProtoISIS learned the domain of ultrasonography and body computed tomography by reviewing 200 consecutive cases of actual requests for imaging procedures. We tested ProtoISIS by using it to classify four sets of 25 cases of actual imaging procedure requests. Case-based reasoning can be applied successfully to the selection of diagnostic imaging procedures and holds potential for use in clinical decision support aids.
Further work is necessary to realize a clinically useful system.