Performance and reproducibility of a computerized mass detection scheme for digitized mammography using rotated and resampled images: an assessment.

OBJECTIVE Our objective was to compare the performance and reproducibility of a computer-aided detection (CAD) scheme that uses multiple rotated and resampled images with an in-house-developed CAD scheme (single-image-based) and a commercial CAD product in detecting masses depicted on digitized mammograms. MATERIALS AND METHODS Ninety-two film mammograms (acquired from 23 patients) were selected. Forty-four mass regions associated with malignancy were visually identified. A commercial CAD system was used to scan and process each image four times, for a total of 368 digitized images depicting 176 mass regions. Images were processed using two CAD schemes developed in our laboratory. One uses the detection results generated from a single image, and the other averages five detection scores generated after processing the originally digitized image and four slightly rotated and resampled images. A region-based analysis was used to compare reproducibility and performance levels among the two in-house schemes and the commercial system. RESULTS The commercial system detected a total of 98 mass regions (55.7% sensitivity) and 136 false-positive regions (an average of 0.37 per image). Among the detected mass regions, 76 represented 19 regions that were detected on all four scans and 22 represented 10 regions that were not fully reproducible. Eighty-eight false-positive detections represented 22 reproducible detections on all four scans. Our single-image-based scheme identified 87 mass regions and 160 false-positive regions. Seventeen mass regions and 28 false-positive regions were detected on all four scans. The multiple-image-based scheme identified 98 mass regions and 132 false-positive regions. Twenty-three mass regions were detected on all four scans. One hundred twelve of the 132 false-positive regions represented 28 reproducible detections. CONCLUSION Averaging detection scores from multiple rotated and resampled images generated from a single digitization of a film can reduce variations in detection scores. Our multiple-image-based scheme improved both performance and reproducibility over the single-image-based scheme. The multiple-image-based scheme yielded an overall performance comparable to that of the commercial system but with improved reproducibility.

[1]  David Gur,et al.  A method to test the reproducibility and to improve performance of computer-aided detection schemes for digitized mammograms. , 2004, Medical physics.

[2]  Luisa P. Wallace,et al.  Changes in breast cancer detection and mammography recall rates after the introduction of a computer-aided detection system. , 2004, Journal of the National Cancer Institute.

[3]  B. Zheng,et al.  Soft-copy mammographic readings with different computer-assisted detection cuing environments: preliminary findings. , 2001, Radiology.

[4]  K Doi,et al.  Effect of case selection on the performance of computer-aided detection schemes. , 1994, Medical physics.

[5]  J Champness,et al.  Reproducibility of prompts in computer-aided detection (CAD) of breast cancer. , 2003, Clinical radiology.

[6]  R A Clark,et al.  False-positive reduction in CAD mass detection using a competitive classification strategy. , 2001, Medical physics.

[7]  W A Kaiser,et al.  Reproducibility--an important factor determining the quality of computer-aided detection (CAD) systems. , 2000, European journal of radiology.

[8]  How not to assess computer-aided detection for mammography. , 2004, AJR. American journal of roentgenology.

[9]  E. Egge,et al.  Computed assisted detection of interval breast cancers. , 2001, European journal of radiology.

[10]  Bin Zheng,et al.  Mammography with computer-aided detection: reproducibility assessment initial experience. , 2003, Radiology.

[11]  Y H Chang,et al.  On the reporting of mass contrast in CAD research. , 1996, Medical physics.

[12]  David Gur,et al.  Computer-aided detection performance in mammographic examination of masses: assessment. , 2004, Radiology.

[13]  Y H Chang,et al.  Applying computer-assisted detection schemes to digitized mammograms after JPEG data compression: an assessment. , 2000, Academic radiology.

[14]  C J D'Orsi,et al.  Computer-aided detection: there is no free lunch. , 2001, Radiology.