Feng Li MD, PhD, Presenter: License agreement, Hologic, Inc License agreement, General Electric Company License agreement, Toshiba Corporation License agreement, Deus Technologies, LLC License agreement, Riverain Medical License agreement, MEDIAN Technologies License agreement, Mitsubishi Corporation

Seiji Kumazawa PhD, Abstract Co-Author: Nothing to Disclose

Junji Shiraishi, Abstract Co-Author: License agreement, Riverain Medical License agreement, MEDIAN Technologies Research support, Riverain Medical Research support, Totoku Electric Co, Ltd

Philip Caligiuri MD, Abstract Co-Author: Nothing to Disclose

Heber M. MacMahon MD, Abstract Co-Author: Consultant, Riverain Medical Research support, MEDIAN Technologies Stockholder, Hologic, Inc

Kunio Doi PhD, Abstract Co-Author: Shareholder, Hologic, Inc License agreement, Hologic, Inc License agreement, Deus Technologies, LLC License agreement, Riverain Medical License agreement, Mitsubishi Corporation License agreement, MEDIAN Technologies License agreement, General Electric Company License agreement, Toshiba Corporation Research support, Deus Technologies, LLC Research support, DuPont Research support, Elbit Medical Imaging Ltd Research support, Fuji Photo Film Co, Ltd Research support, General Electric Company Research support, Hitachi, Ltd Research support, Eastman Kodak Company Research support, Konica Minolta Group Research support, Mitaya Manufacturing Co, Ltd Research support, Mitsubishi Corporation Research support, Koninklijke Philips Electronics NV Research support, Hologic, Inc Research support, Riverain Medical Research support, Seiko Corporation Research support, Siemens AG Research support, 3M Company Research support, Toshiba Corporation

To investigate the subjective similarity for pairs of images with various abnormal patterns of diffuse lung diseases (DLD) on thin-section computed tomography (CT) by experienced radiologists in order to explore a basis for selecting similar images in assisting radiologists’ image interpretation.

A total of 226 regions of interest (ROI) images (75 mm x 75 mm) with 4 major pattern types (ground-glass opacity [GGO], nodular opacity, reticular opacity, and honeycombing) of DLD on thin-section CT in 71 patients (mean age, 54 years; 35 men and 36 women) were identified by three radiologists. One radiologist manually selected 104 image pairs, where the images in each pair had the same pattern type and were similar in appearance. An additional 208 image pairs were randomly selected, evenly divided between the 4 pattern types. The subjective similarity (from “0: not similar at all” to “1.0: almost identical”) for each of pair was rated by 12 experienced radiologists. Similarity ratings and correlation coefficients were analyzed according to radiologist groupings and image pattern types.

The correlation coefficient of subjective similarity for all 312 pairs of images was 0.69 ± 0.05 (mean ± standard deviation) between one radiologist and any another one. For selected pairs with the same pattern types, the mean similarity was 0.72 ± 0.05 by the 12 observers. For randomized pairs, the mean similarity was 0.49 ± 0.06 for the same pattern type and 0.24 ± 0.04 for the varying pattern types (P < 0.001). For randomized pairs with the same pattern types, the mean similarity was higher for GGO (0.63 ± 0.05) and honeycombing (0.58 ± 0.05) than for reticular opacity (0.32 ± 0.05).

Subjective similarity ratings for pairs of abnormal images can be measured reliably and reproducibly by radiologists, and will provide an objective measure for the selection of similar images in assisting radiologists’ image interpretation.

Subjective similarity measurements for pairs of abnormal images can provide an objective measure for the selection of similar images in order to assist radiologists’ image interpretation.

Li, F, Kumazawa, S, Shiraishi, J, Caligiuri, P, MacMahon, H, Doi, K, Investigation of Subjective Similarity for Pairs of Images with Various Patterns of Diffuse Lung Disease on Thin-Section CT: Observer Performance Study.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6012955.html