Title
Trend of Contrast Detection Threshold with and without Localization.
Abstract
Published information on contrast detection threshold is based primarily on research using a location-known methodology. In previous work on testing the Digital Imaging and Communications in Medicine (DICOM) Grayscale Standard Display Function (GSDF) for perceptual linearity, this research group used a location-unknown methodology to more closely reflect clinical practice. A high false-positive rate resulted in a high variance leading to the conclusion that the impact on results of employing a location-known methodology needed to be explored. Fourteen readers reviewed two sets of simulated mammographic background images, one with the location-unknown and one with the location-known methodology. The results of the reader study were analyzed using Reader Operating Characteristic (ROC) methodology and a paired t test. Contrast detection threshold was analyzed using contingency tables. No statistically significant difference was found in GSDF testing, but a highly statistical significant difference (p value <0.0001) was seen in the ROC (AUC) curve between the location-unknown and the location-known methodologies. Location-known methodology not only improved the power of the GSDF test but also affected the contrast detection threshold which changed from +3 when the location was unknown to +2 gray levels for the location-known images. The selection of location known versus unknown in experimental design must be carefully considered to ensure that the conclusions of the experiment reflect the study's objectives.
Year
DOI
Venue
2013
10.1007/s10278-013-9589-4
J. Digital Imaging
Keywords
Field
DocType
Image perception,contrast threshold,GSDF,ROC,SKE,LKE
Computer vision,Mammography,DICOM,Computer science,p-value,Clinical Practice,Linearity,Contingency table,Artificial intelligence,Statistics,Student's t-test,Analysis of variance
Journal
Volume
Issue
ISSN
26
6
1618-727X
Citations 
PageRank 
References 
0
0.34
2
Authors
8