Influence of Enhanced Visualization Processing (EVP) of Chest Images on Workflow

PROJECT PARTICIPANTS Elizabeth Krupinski, PhD 1 Martin Radvany, MD 2 Alan Levy, MD 2 Daniel Ballenger, MD 2 Jonathan Tucker, PhD 2 Anna Chacko, MD 2 Richard VanMetter, PhD 3 1 University of Arizona Tucson, AZ 2 Brook Army Medical Center San Antonio, TX 3 Kodak Health Imaging Rochester, NY

EVP w Increase latitude without reducing contrast needed for diagnostic details? Acquire CR images traditional way Process with Kodak CR system Default processing with nonlinear edge enhancement

EVP w Automatic tone scaling algorithm PTONE (perceptual tone scale) Image analysis Tone scale generation Tone scale application w Utilizes Perceptual Linearization w EVP applied after analysis & generation, before application

EVP w Divides image low & high-frequency component images w Contrast low-frequency reduced, increasing the latitude w Contrast high-frequency enhanced, preserving diagnostic detail w Images recombined & PTONE applied

Preference Study w Van Metter & Foos SPIE 1999 w 70 images, 10 radiologist w Side-by-side comparison w EVP satisfactory or better than control images (92.6% vs 55.6%) w More control images unsatisfactory (4.0% vs 0.6%)

Current Hypothesis w EVP will improve workflow w Reduce use image processing w Reduce time using processing w Reduce overall viewing time

Materials & Methods w BAMC summer 2000 w Kodak CR 400 System with EVP w Fuji CR system without EVP w Portable chest images - 4 ICUs w 1 ICU each day for Kodak => mix of both each day w R & L lead markers on Kodak w Send through PACS

Reading Procedure w Did not alter normal reading routine Used window/level etc. Used zoom Reports dictated Proceeded own pace

Observation w Digital video security camera w VCR w Date & time stamp w Radiologists turned on w Showed ID badge to camera

Panasonic WV-BP x 494 pixels - 30 frames/sec - SNR = 50 dB - Minimum illumination 0.08 lx at F1.4 with automatic gain on Sony VCR & Monitor

Data Analysis w 66 Kodak & 75 Fuji cases w 4 radiologists 1 = 23 Kodak, 25 Fuji 2 = 21 Kodak, 25 Fuji 3 = 17 Kodak, 22 Fuji 4 = 5 Kodak, 3 Fuji w Videotapes reviewed: viewing time & frequency use of image processing

Viewing Time F = 6.271, p = all readers F = 13.58, p = # 4 out

Zoom & Processing w Zoom 64% Kodak cases & 69% Fuji cases X 2 = 0.51, df = 1, p > 0.05 w Window/level etc. 35% Kodak cases & 41% Fuji cases X 2 = 0.49, df = 1, p > 0.05 w No significant differences in usage frequency

Zoom Time Zoom : F = 9.26, p = Modality : F = 9.19, p =

Processing Time Processing : F = 17.61, p < Modality : F = 18.73, p <

Conclusions w Workflow significantly improved with EVP ~ 13 sec on average / case w Savings of 22 minutes / 100 cases w Does not reduce frequency of image processing use w Time associated with use is reduced significantly

Caveats w Not a diagnostic accuracy study ROC study could address this w Used only chest images from the ICU Image & diagnostic task may influence EVP impact on workflow