13. An apparatus for automatic prostate segmentation in magnetic resonance (MR) image data, comprising: means for performing a first intensity normalization on the MR image to adjust for global contrast changes between the MR image and other MR scans; means for performing a second intensity normalization on the MR image to adjust for intensity variation within the MR image due to an endorectal coil used to acquire the MR image, comprising; means for obtaining a mask image from the MR image; means for extracting a bright region from the MR image using the mask image, and means for calculating adjusted intensities to reduce an overall intensity within the bright region such that the adjusted intensities at a boundary of the bright region match a surrounding region in the MR image and gradient features within the bright region are retained; means for obtaining an initial prostate segmentation in the MR image by aligning a learned statistical shape model of the prostate to the MR image using marginal space learning (MSL); and means for refining the initial prostate segmentation using one or more trained boundary classifiers.
13. An apparatus for automatic prostate segmentation in magnetic resonance (MR) image data, comprising: means for performing a first intensity normalization on the MR image to adjust for global contrast changes between the MR image and other MR scans; means for performing a second intensity normalization on the MR image to adjust for intensity variation within the MR image due to an endorectal coil used to acquire the MR image, comprising; means for obtaining a mask image from the MR image; means for extracting a bright region from the MR image using the mask image, and means for calculating adjusted intensities to reduce an overall intensity within the bright region such that the adjusted intensities at a boundary of the bright region match a surrounding region in the MR image and gradient features within the bright region are retained; means for obtaining an initial prostate segmentation in the MR image by aligning a learned statistical shape model of the prostate to the MR image using marginal space learning (MSL); and means for refining the initial prostate segmentation using one or more trained boundary classifiers. 16. The apparatus of claim 13 , wherein the means for refining the initial prostate segmentation using one or more trained boundary classifiers comprises: means for refining a prostate surface mesh resulting from the initial prostate segmentation by calculating a displacement for each of a plurality of vertices of the mesh along a surface normal using the one or more trained boundary classifiers; and means for projecting a shape of the refined prostate surface mesh to a learned statistical shape space of the prostate.