Prototype Design and Phantom Evaluation of a Device for Co-registered MRI/TRUS Imaging of the Prostate.

Magnetic Resonance Imaging (MRI) and transrectal Ultrasound (TRUS) are both used in imaging interventions in men suspected of having and with prostate cancer for diagnosis as well as treatment. Due to the widespread availability and ease of use of TRUS, it is widely acknowledged that availability of spatially registered MRI/TRUS data could provide the optimal combination for characterization of prostate tissue and interventional guidance. To provide such spatially aligned data, we propose a device to support co-registered acquisition of MRI and TRUS data while maintaining a stable configuration (shape) of the prostate. We present the design and evaluation of a custom sleeve that can be introduced transrectally, and can accommodate both TRUS and endorectal MRI probes. Our experiments on a phantom have demonstrated that imaging with this sleeve did not compromise differentiation of internal structures and did not affect the quality of the MR acquisition. Reduction of the signal and contrast were however observed and quantified in the TRUS data. Further evaluation and modification of the device necessary for possible patient studies are discussed.