Arthur Burgess1, Francine Jacobson, Philip Judy. 1. Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA.
Abstract
RATIONALE AND OBJECTIVES: In a previous publication concerning detection of masses in mammograms it was shown that the amplitude (contrast) required for detection increased as mass size increased. The work presented here was designed to measure the variation of amplitude threshold for discrimination between masses as a function of lesion size. MATERIALS AND METHODS: A hybrid image method with digitized masses added to digitized normal mammograms was used. The masses were extracted from surgical specimen radiographs. Observer experiments were performed using the two-alternative forced-choice method with images displayed on a computer monitor. There were two tasks: (1) discrimination between a ductal carcinoma and a fibroadenoma, and (2) discrimination between two ductal carcinomas. Masses were scaled to cover the linear size range from 1 to 16 mm. Three observers took part, two physicists and a radiologist. RESULTS: The discrimination contrast-detail (CD) diagrams were found to have minimum threshold amplitudes at lesion sizes near 4 mm. The detection results had demonstrated an unusual contrast-detail diagram form with threshold amplitudes monotonically increasing with lesion size for lesions larger than 1 mm, which was opposite the usual result for image noise. Discrimination thresholds or masses larger than 4 mm were approximately 1.5-2 times those reported for detection of the lesions. CONCLUSION: The detection results had been explained using a relatively simple model based on signal detection theory with some characteristics of the human visual system included. The observer model cannot explain the discrimination results, so additional complexity must be introduced to the observer model.
RATIONALE AND OBJECTIVES: In a previous publication concerning detection of masses in mammograms it was shown that the amplitude (contrast) required for detection increased as mass size increased. The work presented here was designed to measure the variation of amplitude threshold for discrimination between masses as a function of lesion size. MATERIALS AND METHODS: A hybrid image method with digitized masses added to digitized normal mammograms was used. The masses were extracted from surgical specimen radiographs. Observer experiments were performed using the two-alternative forced-choice method with images displayed on a computer monitor. There were two tasks: (1) discrimination between a ductal carcinoma and a fibroadenoma, and (2) discrimination between two ductal carcinomas. Masses were scaled to cover the linear size range from 1 to 16 mm. Three observers took part, two physicists and a radiologist. RESULTS: The discrimination contrast-detail (CD) diagrams were found to have minimum threshold amplitudes at lesion sizes near 4 mm. The detection results had demonstrated an unusual contrast-detail diagram form with threshold amplitudes monotonically increasing with lesion size for lesions larger than 1 mm, which was opposite the usual result for image noise. Discrimination thresholds or masses larger than 4 mm were approximately 1.5-2 times those reported for detection of the lesions. CONCLUSION: The detection results had been explained using a relatively simple model based on signal detection theory with some characteristics of the human visual system included. The observer model cannot explain the discrimination results, so additional complexity must be introduced to the observer model.
Authors: David L Leong; Louise Rainford; Tamara Miner Haygood; Gary J Whitman; Philip M Tchou; William R Geiser; Selin Carkaci; Patrick C Brennan Journal: J Digit Imaging Date: 2012-10 Impact factor: 4.056
Authors: Eric Clarkson; Matthew A Kupinski; Harrison H Barrett; Lars Furenlid Journal: Proc IEEE Inst Electr Electron Eng Date: 2008-03 Impact factor: 10.961
Authors: David L Leong; Louise Rainford; Tamara Miner Haygood; Gary J Whitman; William R Geiser; Beatriz E Adrada; Lumarie Santiago; Patrick C Brennan Journal: J Digit Imaging Date: 2013-12 Impact factor: 4.056