Radiomics-Based Mammographic Abnormality Identification via Radiologist Annotations
Ravi Bullock, Yiwen Xu, Rasika RajapaksheAbstract
Objective
This study developed a radiomics-based pipeline to identify suspicious findings on 2D screening mammograms by training models to distinguish radiologist-annotated abnormalities from normal breast tissue.
Methods
A total of 1,604 screening mammograms (n = 1,294 participants) were used in this retrospective study. Each mammogram included an original capture image, and a secondary capture image with a single radiologist-drawn annotation indicating a region of interest (ROI) with an abnormality. The annotation on each secondary capture image was used to select an ROI in the original image. An ROI with normal tissue was automatically selected from the remaining breast tissue for comparison. Radiomics features were extracted from the ROIs with abnormalities and normal tissue. Feature selection was performed using the SciKit-Learn SelectKBest method with Chi-squared, ANOVA F-, and mutual information score functions. Logistic regression, random forest, XGBoost, bagging, discriminant analysis, and support vector machines classifiers were trained on the selected features. The model performance was evaluated with the area under the receiver operating characteristic curve (AUC) on a holdout test set.
Results
While AUC values ranged from 0.69 to 0.73, no significant differences were observed between models (DeLong test, p > 0.05). The nominally highest performance was achieved via ANOVA F-score feature selection and discriminant analysis (AUC: 0.73; 95% CI: 0.70–0.77).
Conclusion
The radiomics-based pipeline shows promise in distinguishing abnormalities from normal tissue on screening mammograms.
Advances in knowledge
Radiomics has the potential to enhance breast cancer detection and is a step towards the integration of advanced machine learning into screening workflows.