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Contrast‐detail curves for liver CT
Author(s) -
Judy Philip F.,
Swensson Richard G.,
Nawfel Richard D.,
Chan Karen H.,
Seltzer Steven E.
Publication year - 1992
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.596791
Subject(s) - contrast (vision) , window (computing) , visibility , optics , artificial intelligence , computer vision , physics , mathematics , nuclear medicine , computer science , medicine , operating system
Contrast‐detail curves were constructed for liver computed tomographic (CT) images using an objective method. Stimuli were created by superimposing disks at specified locations on sets of 92 normal liver CT images. Bright and dark disks of 9 sizes and 36 possible image contrasts were used. Sets of 92 stimuli were rendered on film at five window widths (64, 128, 256, 512, and 1024 HU). The contrast‐detail (CD) curve flattened substantially for disks larger than 7‐mm diameter, and its slope (on a log‐log plot) was less than predicted from signal‐detection theory. Manipulation of display window manipulation had little impact on this disks' visibility. The results indicate that human observers have difficulty visualizing large, low‐contrast details on liver CT scans, and suggest that narrowing the display window will have little effect on this limitation.