REAL AND SIMULATED CLUSTERED MICROCALCIFICATIONS IN DIGITAL MAMMOGRAMS - ROC STUDY OF OBSERVER PERFORMANCE

We have developed a model to simulate clustered microcalcifications on digital mammograms. Wavelet transform techniques were used to detect real clustered microcalcifications. A feature analysis process was app lied to automatically extract the features describing the individual s imulated microcalcifications and clusters from the values of the real clustered microcalcifications present in the mammogram. Subsequently, a database of simulated and real clustered microcalcifications was cre ated. Clusters of microcalcifications from this database were tested f or indistinguishability from real ones. Two radiologists and one physi cist were asked to indicate whether the microcalcifications were eithe r real or simulated. The responses of the readers were evaluated with a ROC analysis and the area under the curve was calculated. The averag e ROC area was 0.54 +/- 0.03, indicating there was no statistical diff erence between real and simulated clustered microcalcifications. The m ethod allows for the creations of simulated clustered microcalcificati ons that are virtually indistinguishable from real microcalcifications in digital mammograms and could be used to evaluate different image p rocessing techniques. (C) 1997 American Association of Physicists in M edicine.