Multiview-based computer-aided detection scheme for breast masses

Abstract

In this study, we developed and tested a new multiview-based computer-aided detection (CAD) scheme that aims to maintain the same case-based sensitivity level as a single-image-based scheme while substantially increasing the number of masses being detected on both ipsilateral views. An image database of 450 four-view examinations (1800 images) was assembled. In this database, 250 cases depicted malignant masses, of which 236 masses were visible on both views and 14 masses were visible only on one view. First, we detected suspected mass regions depicted on each image in the database using a single-image-based CAD. For each identified region (with detection score > or = 0.55), we then identified a matching strip of interest on the ipsilateral view based on the projected distance to the nipple along the centerline. By lowering CAD operating threshold inside the matching strip, we searched for a region located inside the strip and paired it with the original region. A multifeature-based artificial neural network scored the likelihood of the paired "matched" regions representing true-positive masses. All single (unmatched) regions except for those either with very high detection scores (> or = 0.85) or those located near the chest wall that cannot be matched on the other view were discarded. The original single-image-based CAD scheme detected 186 masses (74.4% case-based sensitivity) and 593 false-positive regions. Of the 186 identified masses, 91 were detected on two views (48.9%) and 95 were detected only on one view (51.1%). Of the false-positive detections, 54 were paired on the ipsilateral view inside the corresponding matching strips and the remaining 485 were not, which represented 539 case-based false-positive detections (0.3 per image). Applying the multiview-based CAD scheme, the same case-based sensitivity was maintained while cueing 169 of 186 masses (90.9%) on both views and at the same time reducing the case-based false-positive detection rate by 23.7% (from 539 to 411). The study demonstrated that the new multiview-based CAD scheme could substantially increase the number of masses being cued on two ipsilateral views while reducing the case-based false-positive detection rate.

Spatial Localization Accuracy of Radiologists in Free-Response Studies: Inferring Perceptual FROC Curves from Mark-Rating Data

“…As ζ decreases from ∞ to −∞, y(ζ) increases from 0 to y max (y max ≤ 1) and x(ζ) increases from 0 to x max . These are common characteristics of observed FROC curves (2,3,5,(20)(21)(22). The end-point (x max , y max ) is reached when all marked regions are counted.…”

Mammographic CAD: Correlation of regions in ipsilateral views - a pilot study

“…3. Variations on the arc method have been used by Paquerault et al 4 , Zheng et al 5 and van Engeland et al 6 to reduce the search region in their CAD algorithms. 3.…”

“…While there have been a few studies indicating the usefulness of using two standard mammographic views for false-positive reduction, [3][4][5][6] these algorithms have not been incorporated into CAD systems. Most importantly in these dual-view algorithms, the suspicious features are identified in both standard mammographic views and information is correlated between pairs of suspicious features to identify matches and thereby reduce the number of false-positives.…”

FluorescenceIn SituHybridization (FISH) Signal Analysis Using Automated Generated Projection Images

“…3g) as the best focused FISH image that is also consistent with the visual selection. Once a cell candidate is detected and segmented, a classifier based on criteria of region size and circularity [31] is applied to identify or classify whether this candidate represents an analyzable cell or un-analyzable object (i.e., debris or clustered cells). Then, the CAD scheme uses the (x, y) coordinate of the detected cell center and cell boundary in the ROI to define a volume of interest (VOI) in another image stack that records the FISH-probed chromosome signals.…”