Preliminary evaluation of effectiveness of logical flow charts in teaching roentgen diagnosis.

Abstract

IN A PREVIOUS publication (3), it was proposed that the analytical processes of roentgen interpretation might be defined and represented in the form of logical flow charts analogous to those employed in computer programming. Further, it was suggested that such flow charts might contribute significantly to the teaching of roentgen diagnosis. Others have protested that the interpretation of films depends on factors so numerous, so diverse, and so subtle as to defy succinct definition, that roentgen diagnosis is essentially an art and as such cannot be represented by an inflexible schema. Mindful of these opposing views a limited study was undertaken in an effort to test objectively the validity of the flow-chart concept and to assess its applicability to radiologic teaching. It is the purpose of this report to present the findings of this study. Rationale of Study The study was based on the premise that if an individual without prior radiologic training were able, with the guidance of a flow chart, to consistently interpret a particular type of roentgen examination correctly, then it would be reasonable to assume that the flow chart he employed accurately represented the processes of roentgen diagnosis for that particular type of study. Accordingly, the ability of radiologically naive observers to interpret roentgenograms correctly with the guidance of a flow chart was taken as an index of the accuracy with which a flow chart can reprerepresent the processes of roentgen diagnosis. By the same token the ability of these subjects subsequently to interpret roentgenograms correctly without the guidance of the flow chart was taken as an index of its effectiveness in teaching roentgen diagnosis. Elements of the Study Flow Chart A modified version of the previously published schema (4) for the analysis of the barium enema was employed throughout the study. This flow chart offered several advantages: (a) It dealt with a complex examination, yet one characterized by relatively few diagnostic possibilities; (b) roentgen shadows whose perception was critical to the flow-chart analysis were in general easily perceived and highly characteristic; and (c) further and quite incidentally its use promised to provide some objective evidence of the importance of the "fluoroscopic impression" in the diagnosis of gastrointestinal studies. Because of mechanical failure on the part of the random access projector it was not possible to present the flow chart in the form of "programmed teaching slides" (4). Instead, it was presented in the form of a numbered sequence of index cards, each of which bore one of the questions or one of the outputs of the flow chart together with procedural directions. Subjects Three subjects were selected who not only were untrained with respect to radiologic methods, but who had no knowledge of clinical medicine.