Detection of masses and clustered microcalcifications on data compressed mammograms: An observer performance study

OBJECTIVE. To evaluate observers' ability to detect breast masses and clust ered microcalcifications depicted on data compressed mammograms, an observe r performance study was performed. MATERIALS AND METHODS. Eight observers assessed 60 mammographic images obta ined in six modes, ranging from noncompressed to a maximum data compression level of 101:1. Observers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of a mass and also independently fo r the likelihood of the presence of clustered microcalcifications. In addit ion, observers were asked to rate their subjective assessment of the qualit y of each image for the detection of a mass and separately for the detectio n of microcalcifications. Receiver operating characteristic analyses were p erformed. RESULTS. The average area under the receiver operating characteristic curve , A,, for the detection of clustered microcalcifications decreases signific antly at the highest data compression level when compared with the noncompr essed and two lowest levels of data compression (P < 0.01), and a trend tes t of the average area under the receiver operating characteristic curve for all observers is statistically significant (p < 0.05). No statistically si gnificant differences among or between any of the data compression level mo des for the detection of masses were detected. CONCLUSION. At a high level of mammogram data compression, observer perform ance was degraded for the detection of clustered microcalcifications. Detec tion of masses was not affected by the data compression methods and levels used in this study.