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Volume 39, Issue 6, June 2012
Transrectal ultrasound(TRUS)imaging is clinically used in prostate biopsy and therapy. Segmentation of the prostate on TRUSimages has many applications. In this study, a three-dimensional (3D) segmentation method for TRUSimages of the prostate is presented for 3D ultrasound-guided biopsy.Methods:
This segmentation method utilizes a statistical shape, texture information, and intensity profiles. A set of wavelet support vector machines (W-SVMs) is applied to the images at various subregions of the prostate. The W-SVMs are trained to adaptively capture the features of the ultrasoundimages in order to differentiate the prostate and nonprostate tissue. This method consists of a set of wavelet transforms for extraction of prostate texture features and a kernel-based support vector machine to classify the textures. The voxels around the surface of the prostate are labeled in sagittal, coronal, and transverse planes. The weight functions are defined for each labeled voxel on each plane and on the model at each region. In the 3D segmentation procedure, the intensity profiles around the boundary between the tentatively labeled prostate and nonprostate tissue are compared to the prostate model. Consequently, the surfaces are modified based on the model intensity profiles. The segmented prostate is updated and compared to the shape model. These two steps are repeated until they converge. Manual segmentation of the prostate serves as the gold standard and a variety of methods are used to evaluate the performance of the segmentation method.Results:
The results from 40 TRUSimage volumes of 20 patients show that the Dice overlap ratio is 90.3% ± 2.3% and that the sensitivity is 87.7% ± 4.9%.Conclusions:
The proposed method provides a useful tool in our 3D ultrasoundimage-guided prostate biopsy and can also be applied to other applications in the prostate.
The professions of Medical Physics and Clinical Engineering should be combined into a single profession “Clinical Science and Technology”39(2012); http://dx.doi.org/10.1118/1.3694114View Description Hide Description