Volumetric image interpretation in radiology: scroll behavior and cognitive processes

Abstract

The interpretation of medical images is a primary task for radiologists. Besides two-dimensional (2D) images, current imaging technologies allow for volumetric display of medical images. Whereas current radiology practice increasingly uses volumetric images, the majority of studies on medical image interpretation is conducted on 2D images. The current study aimed to gain deeper insight into the volumetric image interpretation process by examining this process in twenty radiology trainees who all completed four volumetric image cases. Two types of data were obtained concerning scroll behaviors and think-aloud data. Types of scroll behavior concerned oscillations, half runs, full runs, image manipulations, and interruptions. Think-aloud data were coded by a framework of knowledge and skills in radiology including three cognitive processes: perception, analysis, and synthesis. Relating scroll behavior to cognitive processes showed that oscillations and half runs coincided more often with analysis and synthesis than full runs, whereas full runs coincided more often with perception than oscillations and half runs. Interruptions were characterized by synthesis and image manipulations by perception. In addition, we investigated relations between cognitive processes and found an overall bottom-up way of reasoning with dynamic interactions between cognitive processes, especially between perception and analysis. In sum, our results highlight the dynamic interactions between these processes and the grounding of cognitive processes in scroll behavior. It suggests, that the types of scroll behavior are relevant to describe how radiologists interact with and manipulate volumetric images.

Visual Search Performance and Strategy for Three-Dimensional Visualization Systems: Impact of Radiologist Experience

“…This finding is consistent with the results of earlier work [43], in which radiologists demonstrated a more organized search in the z-direction compared to non-radiologists when inspecting multi-slice images on a flat-panel display. This result is compatible with the assumption that bottom-up processing plays a major role in the perception of early-career radiologists, as was emphasized in previous experimental studies [45,53,54].…”

“…The human-computer interaction was increasingly studied, investigating its relation to cognitive processes [8,44,45] and the visual search outcome [2,33] during image interpretation in radiology. The major part of relevant research has been conducted using medical images (e.g., [2,43,45]), and few studies with non-medical search items have also included image manipulations in the experimental design [39,42]. Similar to our findings, the number of manipulations was reported [39] to increase for radiologists and non-radiologists when they viewed high-complexity images on a flat-panel display.…”

“…In addition to visual performance, another important aspect of ergonomic evaluation is the interaction technique that users implement when viewing images on a display. The interaction technique of radiologists was broadly assessed in the context of testing new radiology workstations [39,42], studying effective search strategies for multi-slice computer tomography viewing [2,33,43], and studying the cognitive processes of radiologists during medical image reading [44,45]. With the advent of multi-slice images, researchers mostly investigated how radiologists manipulated images in the z-direction, the feature which sharply distinguishes the new type of images from two-dimensional ones.…”

“…The emergence of new visualization systems in radiology changes the way radiologists conduct visual searches [1,2] and affects radiology education [15]. Whereas three-dimensional visualization systems are expected to be used extensively for professional purposes in medicine, most research into search strategies when viewing multi-slice images are conducted for flat-panel displays (e.g., [2,43,45]). Further investigation of image manipulation techniques is required to maximize the usability of new three-dimensional displays for specific users.…”

“…However, it is often difficult to recruit participants to be involved in the study, because professionals do not have time to participate as experimental observers. The previous user studies employed residents [39,45] or analyzed the results of radiologists and residents together [2,14,18] to investigate visual search through medical images and test the application of new workstations for professional purposes. Similar to the case of performance assessment using multi-slice images [43], the results of our study highlighted that the performance accuracy can be similar, however, the image manipulation strategies differ significantly depending on the amount of radiologist experience.…”