1. Automatic Detection And Classification Of Microcalcifications In Digital Mammograms Institute for Brain and Neural Systems Brown University Providence RI

2. The CALMA Project (Computer Assisted Library for MAmmography) represents a collaborative effort of several institutions from Italy and USA: INFN (National Institute for Nuclear Physics) sections (Bologna, Pisa and Udine), medical centers of mammographic screening (Bari, Bologna and Udine) and the Institute for Brain and Neural Systems at Brown University. Its purpose is to develop a CAD (Computer Assisted Diagnosis) system for the detection and classification of mammographic lesions, based on neural networks and expert systems. The CAD systems have been quite successful as diagnosing tools, in many cases outperforming estimates by expert radiologists. Our goal is to build a system which consists of a scanner (or a digital mammogram) and dedicated hardware and software that can assist radiologists in their diagnoses. We are currently developing a software package including tools for image processing, detection and classification of lesions. At the moment we are analyzing the most common lesions in mammograms: clustered microcalcifications. Our data set consists of two databases. The first database has been compiled at Bari and Udine hospitals and contains 2000 images. The second database, for evaluation of our results, is a Nijmegen database which contains 40 images. Our approach for preprocessing and image enhancement of digital mammographs combines classical image and multiresolution wavelet analysis techniques. Once the Regions Of Interest (ROI) have been detected, a set of features characterizing their texture is extracted from each ROI. Since the number of texture features is very large, we apply a feature reduction scheme based on their mutual correlation and discrimination power. A Neural Network (NN) based classifier is then trained on the remaining features in order to separate the two classes of lesions (benign and malignant tumors). Outline of the Project

3. Possible Types of Lesions microcalcifications masses star-shaped lesions (single or clustered)

4. Microcalcifications Microcalcifications look like little spots (0.1  0.3mm) with high brightness compared to the surrounding tissue. They are clinically important if clustered in groups of three, or more, within an area of about 1cm 2.

5. Example of Microcalcifications in a Mammogram