Intra procedure Deformable Ultrasound MRI Fusion for Prostate Biopsies

This Phase II proposal is a continuation of our successful Phase I grant whose overarching goal is to develop a
more robust and accurate method for the deformable fusion of pre operative magnetic resonance images MRI
and intra procedure trans rectal ultrasound TRUS images to guide prostate biopsy Prostate cancer is a major
cause of death in the U S and biopsy is the gold standard for its diagnosis Each year over million biopsies
are performed in the U S alone at a cost of well over $ billion Most of these biopsies are performed under TRUS
guidance in a systematic fashion but blinded to potential tumor locations because many tumors are invisible on
ultrasound This procedure is highly inef cient and as many as of serious tumors may be missed on a rst
time biopsy Multi parametric MRI mpMRI acquired before the biopsy can be used to de ne potential targets
and then used in conjunction with live TRUS imaging to perform targeted image guided biopsy A key challenge
is the accurate registration fusion of the intra procedure TRUS with the pre acquired MRI This fusion procedure
is often performed using rigid registration which does not account for prostate deformation between the MRI and
TRUS acquisitions Eigenandapos s Artemis system is one of a newer generation of devices that performs deformable
mapping between MRI and TRUS Current fusion methods such as in Artemis however are highly operator
dependent as they rely on semi automated TRUS segmentation by the clinician during the procedure which is
error prone time consuming and critically reliant on operator skill We propose to extend the development of
our strategy for deformable registration from Phase I based on a statistical deformation model learned from
an existing large multi institutional database N of MRI TRUS prostate image pairs We will learn the
statistics of both biopsy deformation and prostate shape clusters The model will reduce the dimensionality of
the search as well as constrain the deformation The proposed registration method will use a regional con dence
estimate for the intra procedure interactive TRUS segmentation in order to enhance robustness by focusing the
registration on the more con dent portions of the bounding surface We will also generate regional anisotropic
estimates of registration uncertainty These methods will streamline the clinicianandapos s work ow by providing a more
accurate and robust registration with less dependence on segmentation errors This project is signi cant in that
it has the potential to improve the utilization of MRI TRUS fusion guided prostate biopsy especially outside of
major academic hospitals by alleviating the dependence of the work ow on exact prostate segmentation from
often poor quality TRUS images In Aim we will further improve our fusion algorithm integrate it into the
Artemis system and test for improved accuracy In Aim we will create an innovative research interface to our
new algorithm to allow for clinical testing and then perform a two site clinical validation in N patients We will
compare our new method to the current non rigid MRI TRUS fusion method used in our FDA cleared Artemis
system to demonstrate improved accuracy Prostate cancer is the second most common form of cancer behind skin cancer and biopsy is the clinical gold
standard for diagnosis This grant is aimed at enhancing the accuracy and robustness of state of the art MRI
ultrasound fusion guided prostate biopsies with an expected improved detection of disease resulting in earlier
diagnosis and improved survival At the core of the effort is the development and validation of novel image
analysis methods for MRI ultrasound registration using a statistical model of deformation and shape based on
population statistics of prostate deformation