Whole breast lesion detection using naive bayes classifier for portable ultrasound

In recent years, portable PC-based ultrasound (US) imaging systems developed by some companies can provide an integrated computer environment for computer-aided diagnosis and detection applications. In this article, an automatic whole breast lesion detection system based on the naive Bayes classifier using the PC-based US system Terason t3000 (Terason Ultrasound, Burlington, MA, USA) with a hand-held probe is proposed. To easily retrieve the US images for any regions of the breast, a clock-based storing system is proposed to record the scanned US images. A computer-aided detection (CAD) system is also developed to save the physicians' time for a huge volume of scanned US images. The pixel classification of the US is based on the naive Bayes classifier for the proposed lesion detection system. The pixels of the US are classified into two types: lesions or normal tissues. The connected component labeling is applied to find the suspected lesions in the image. Consequently, the labeled two-dimensional suspected regions are separated into two clusters and further checked by two-phase lesion selection criteria for the determination of the real lesion, while reducing the false-positive rate. The free-response operative characteristics (FROC) curve is used to evaluate the detection performance of the proposed system. According to the experimental results of 31 cases with 33 lesions, the proposed system yields a 93.4% (31/33) sensitivity at 4.22 false positives (FPs) per hundred slices. Moreover, the speed for the proposed detection scheme achieves 12.3 frames per second (fps) with an Intel Dual-Core Quad 3 GHz processor and can be also effectively and efficiently used for other screening systems.