Allison Lara Zwingenberger DVM, Presenter: Board of Directors, SciCan Ltd

The purpose of this study was to enhance students' ability to detect a true structure on a radiograph by selectively increasing contrast in the image.

Standard computer software (Photoshop CS3 Extended, Adobe Systems Incorporated, San Jose, CA) was used to highlight the abnormal structures. Duplicate slides with the features of interest highlighted were displayed sequentially during lectures. Instructor evaluations for two introductory veterinary radiology courses over three years were surveyed retrospectively for comments specific to the highlighted slides. Contrast enhancement was analyzed by measuring the difference in grayscale across the margin of the structure of interest before and after enhancement.

Analysis of contrast enhancement The selected radiographs included 14 positive highlights (soft tissue opacity) and 6 negative highlights (gas lucency). The mean difference in contrast before enhancement was 27.2 (95% CI (21.1, 33.2), range (10-56)), and after contrast enhancement was 61.6 (95% (CI 52.5, 70.6), range (37-100). This contrast difference was significantly increased compared to unenhanced radiographs (P<0.001). The mean ratio of contrast enhancement was 2.5 (range (1.7-3.8)). Survey Responses 478 responses to two questions evaluating the effectiveness of learning materials provided by the instructor were analyzed. 46% of all students answering questions 1 and 2 mentioned the slides or highlights. 19% of students mentioned the slides, 13% mentioned the highlights, and 14% mentioned both slides and highlights in their responses to questions 1 and 2. The responses were categorized as positive (100%) for all years (2008, 99%; 2009, 100%; 2010, 100%). There was one negative response in 2008. Of the 219 responses that mentioned the slides and/or highlights, students reported one or more of the following: improved clarity or visualization of the structures on radiographs (32%), that the materials were helpful or effective (33%), improved learning (9%), better understanding of the material (7%), and provided opportunity for self testing (6%).  

Selectively enhancing contours of interest on abdominal radiographs enhanced the learning experience of novice veterinary students learning radiology. 

Simple digital enhancements to radiographs used in presentations can be used to clearly demonstrate features of interest.

Zwingenberger, A, Seeing Is Believing: Selective Contrast Enhancement of Radiographs to Enhance Student Learning and Visual Perception.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009399.html