Abstract

GOMEZ, W.; LEIJA, L.; PEREIRA, W. C. A.  and  INFANTOSI, A. F. C. Segmentation of Breast Nodules on Ultrasonographic Images Based on Marke d-Controlled Watershed Transform. Comp. y Sist. [online]. 2010, vol.14, n.2, pp.165-174. ISSN 2007-9737.

In this article is presented a computerized segmentation method for breast nodules on ultrasonic images. With the goal of removing the speckle while preserving important information from the lesion boundaries, a Gabor filter followed by an anisotropic diffusion filtering are applied to the ultrasonic image. Furthermore, the marker-controlled Watershed transform defines potential boundaries that maximize the Average Radial Derivative function to get the final lesion contour. The segmentation procedure was applied on a database of 50 images and the computer-delineated margins were compared against manual outlines drawn by two radiologist. This comparison was performed by two metrics, which measure the similarity between two compared images: overlap ratio (OR) and normalized residual value (nrv). If there is perfect agreement between both images OR = 1 and nrv = 0. Then, the mean values results, for each metric, were for the first radiologist: OR = 0.87±0.04 and nrv = 0.14±0.06, and for the second radiologist: OR = 0.86±0.06 and nrv = 0.15±0.05.

Keywords : Breast ultrasound; Segmentation; Watershed transform; Average radial derivative.

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