User interface design for medical imaging workstations: image display and processing

Conventional diagnostic protocols in radiological viewing require the availability of a large display space, as exemplified by the film alternator (or lightbox). However, the recent trend in medical imaging workstation design is the use of relatively small display screens to present radiological images. In the study, the efficacy of an alternatorfilmstrip metaphor for navigating through and displaying the images of a patient study is evaluated. The metaphor relies on the availability of a ‘pictorial directory’ and accommodates the concurrent display of a variable number of images on the screen. In addition the study also evaluated the utility of two commonly available operations for manipulating the appearance of an image: contrast enhancement and image magnification. The study consisted of two experimental variables: availability of a pictorial directory (yes, no) and number of concurrently displayed images (1, 2, or 4). Twelve radiologists viewed two sets of X-ray computed tomography (CT) studies for each of the six treatment conditions and were asked to record an interpretation for each study. Results indicate that interpretations using the two-image display formats took the least amount of time per study, whereas the single-image format with access to the pictorial directory required the longest mean interpretation time. The image magnification capability was generally not found to be useful for image interpretation, whereas the contrast manipulation operations were judged extremely helpful. Implications of the results for medical imaging workstation design are discussed.