Case-Based Reasoning Computer Algorithm that Uses Mammographic Findings for Breast Biopsy Decisions
Carey E. Floyd, Jr.1,2,
Joseph Y. Lo1,2 and
Georgia D. Tourassi1
1
Department of Radiology, Duke University Medical Center, Box 2623, Durham, NC
27710. 2
Department of Biomedical Engineering, Duke University Medical Center, Durham,
NC 27710.
Fig. 1.Histogram shows benign and malignant cases binned by
malignancy fraction output of case-based reasoning system. Note that although
benign and malignant cases overlap considerably, 81 cases with malignancy
fraction of less than 0.1 are all benign. These patients could be spared
surgery without missing any malignancies. Dark shading indicates malignant;
light shading indicates benign.
Fig. 2.Histogram of benign and malignant cases binned by malignancy
fraction expanded around high-sensitivity region binned by malignancy
fraction. Note that if threshold were set at 0.15, additional 40 benign cases
would not have been biopsied, and one malignancy would have been missed. Dark
shading indicates malignant; light shading indicates benign.
Fig. 3.Mammogram of 73-year-old woman with cluster of
microcalcifications (>10) described as fine-branching. Cluster is at tip of
white arrowhead. Both mammographer and case-based reasoning would correctly
recommend biopsy of this malignant lesion.
Fig. 4.Mammogram of 43-year-old woman with isodense lobulated 18-mm
mass with well-circumscribed margin. Mass is at tip of white arrowhead. Both
mammographer and case-based reasoning would correctly recommend no biopsy of
this benign lesion.
Fig. 5.Mammogram of 45-year-old woman with isodense irregular 25-mm
mass with obscured margin. Mass is at tip of white arrowhead. Mammographer
correctly recommended biopsy of this malignant lesion. Case-based reasoning
would miss this malignancy if threshold were increased to avoid 40 more
biopsies.