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Although CAD schemes can detect a high percentage of subtle cancers depicted on "prior" and false-negative
cases, radiologists frequently discard most of CAD-cued subtle masses in the clinical environment. As a result of the
relatively high false-positive detection rate and the fact that a large number of subtle masses are typically cued only on
one view cause radiologists to rely less on (and often ignore) CAD-cued masses. In this study, we present a multi-view
based method to increase the number of actual masses that are cued by the CAD scheme on both (ipso-lateral) views
and at the same time limiting the overall "case-based" false-positive detection rate. The new scheme includes a
traditional single-image based CAD scheme and a multi-view processing module. An image database from 435
examinations (or a total of 1,740 images) consisting 235 examinations depicting a verified malignant mass each and 200
negative examinations was used in this study. The single-image based CAD scheme with a fixed operating threshold
(i.e. 0.55) was applied to all images. For each CAD identified region (i.e. with detection score ≥ 0.55), the multi-view
processing module defined a matched strip on the corresponding ipso-lateral image and identified all "matched" regions
located inside the strip (including those with detection score < 0.55). All matched regions are cued on both views and
unmatched regions were discarded. CAD scheme initially detected 172 true masses and 576 false-positive regions. Of
the 172 masses, 90 were detected on two views (52%) and 82 were detected only on one view. Of the 576 false-positive
detections, only 72 pairs (14%) were considered "matched" and 432 were not, resulting in 504 case-based
("independent") cues. Case-based sensitivity and false-positive rate of the CAD scheme were 73.2% and 1.16 per case.
When only matched region pairs were cued, 160 masses (68.1%) and 308 false-positive detections (0.71 per case) were
identified on two views. Reducing the original operating threshold from 0.55 to 0.49 resulted in 172 masses and 413
false-positive detections (or 0.95 per case) being cued on two views. By increasing sensitivity through the reduction of
the detection threshold only inside the matched strip regions in ipso-lateral images the scheme successfully cued masses
on two views by maintaining detection sensitivity while reducing the "case-based" false-positive detection rate.
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