3D registration of ultrasound with histology in the prostate

The authors hypothesize that frequency shift and power mode Doppler imaging in 3D can provide valuable diagnostic information for the detection and staging of prostate cancer. 3D data sets of both Doppler modes are taken of each prostate prior to radical prostatectomy. An in vitro b-mode scan is performed after surgery. The prostate is then cut into 3 mm sections and H&E and factor 8 stained whole mount slides are made. The in vitro scan and the sectioning are done in the same orientation, so that the slides can easily be aligned with the in vitro scan. The boundary of the prostate is fit with an ellipsoid and the urethra is identified in the two Doppler scans and the stacked histology slides, providing the scaling, translational, and rotational components of an affine transform. The resulting transform is used to register the volumetric data sets from a particular prostate, which allows quantitative vascular measures to be made in and around regions of histologically identified cancer. It can also be used to align data from different prostates to produce a probability map of where cancer occurs and a vascularity density map of cancerous prostates.