Wiard Jorritsma - Empirical and Model-based Usability Evaluations of Multiple Radiology PACS Workstation Interfaces

Previous research on the Picture Archiving and Communication System (PACS), which is the main software component of the radiology workstation, focuses on functionality and largely ignores the interaction between radiologists and the PACS. This interaction is what determines the PACS’s usability (i.e. the degree to which radiologists can effectively, efficiently and enjoyably work with the PACS). To study this interaction and to compare the usability of different PACS interfaces, I performed empirical and model-based usability evaluations of three PACSs. The results showed that one PACS had distinctly better usability than the others and that radiologists could therefore work with this PACS more efficiently and with greater satisfaction. The results provided detailed insights in the way radiologists interact with a PACS and were used to define improvements for this interaction. This thesis also compares the usefulness of two model-based usability evaluation methods, GOMS and CogTool, for a PACS usability study. The model predictions of both methods correlated positively with the empirical data, and this correlation was stronger for GOMS than for CogTool. This finding, combined with GOMS’s greater practical convenience for modeling user interaction with a PACS, makes GOMS more suitable for a PACS usability study than CogTool.