An efficient and robust medical-image indexing procedure should be user-oriented. It is essential to index the images at the right level of description and ensure that the indexed levels match the user's interest level. This study examines 240 medical-image descriptions produced by three different groups of medical-image users (novices, intermediates, and experts) in the area of radiography. This article reports several important findings: First, the effect of domain knowledge has a significant relationship with the use of semantic image attributes in image-users' descriptions. We found that experts employ more high-level image attributes which require highreasoning or diagnostic knowledge to search for a medical image (Abstract Objects and Scenes) than do novices; novices are more likely to describe some basic objects which do not require much radiological knowledge to search for an image they need (Generic Objects) than are experts. Second, all image users in this study prefer to use image attributes of the semantic levels to represent the image that they desired to find, especially using those Received July 3, 2011; revised September 16, 2011; accepted September 16, 2011 © 2011 ASIS&T • Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/asi.21686 specific-level and scene-related attributes. Third, image attributes generated by medical-image users can be mapped to all levels of the pyramid model that was developed to structure visual information. Therefore, the pyramid model could be considered a robust instrument for indexing medical imagery.
IntroductionMedical images provide vital clinical data and are considered a powerful educational resource due to their immediate, informative, and illustrative nature. Medical images can be used by clinicians for their daily practice of medicine, such as making diagnoses, planning treatment, and monitoring responses to therapy as well as for medical education and research (Cleveland & Cleveland, 2009;Kalpathy-Cramer & Hersh, 2010;Müller, Michoux, Bandon, & Geissbuhler, 2004). Past studies have reported significant learning improvements when using medical images during classes and self-education for medical students and residents (Dawes, Vowler, Allen, & Dixon, 2004; KalpathyCramer & Hersh, 2010). A single hospital radiology department alone produced 50,000 images per day in 2006 (Müller , 2007). With the dramatic explosion of digital image collections in medicine, it is important to develop advanced techniques for effective and efficient management of this information, enabling users quick and easy access in a clinically meaningful way.Image information systems (e.g., picture archiving and communication systems) provide rapid access to digitalized film images and allow users to access medical-image databases based on combinations of a patient's identification, visit dates, and study characteristics (e.g., modality and study description) (Müller et al., 2004). However, to fulfill users' various requirements under different contexts of u...