10. An apparatus for detecting a 3D anatomical object in a medical image volume, comprising: means for determining a constrained search range in the medical image volume based on a set of annotated training volumes; means for detecting position candidates in said constrained search range using a first trained classifier; means for generating position-orientation hypotheses from said position candidates based on orientation examples in said set of training volumes; means for detecting position-orientation candidates from said position-orientation hypotheses using a second classifier; means for generating similarity transformation hypotheses from said position-orientation candidates based on scale examples in said set of training volumes; means for detecting similarity transformation candidates from said similarity transformation hypotheses using a third trained classifier; and means for detecting said 3D anatomical object in the medical image volume based on at least one of said similarity transformation candidates.
10. An apparatus for detecting a 3D anatomical object in a medical image volume, comprising: means for determining a constrained search range in the medical image volume based on a set of annotated training volumes; means for detecting position candidates in said constrained search range using a first trained classifier; means for generating position-orientation hypotheses from said position candidates based on orientation examples in said set of training volumes; means for detecting position-orientation candidates from said position-orientation hypotheses using a second classifier; means for generating similarity transformation hypotheses from said position-orientation candidates based on scale examples in said set of training volumes; means for detecting similarity transformation candidates from said similarity transformation hypotheses using a third trained classifier; and means for detecting said 3D anatomical object in the medical image volume based on at least one of said similarity transformation candidates. 17. The apparatus of claim 10 , wherein said means for detecting said 3D anatomical object in the medical image volume based on at least one of said similarity transformation candidates comprises: means for aggregating a number of said similarity transformation candidates having a highest probability to determine a position, orientation, and scale of said 3D anatomical object in said medical image volume.