The objective of the proposed study is to evaluate a new, molecular image directed, three-dimensional (3D) ultrasound guided biopsy system in human patients. The current biopsy uses ultrasound imaging as guidance. However, the procedure uses two-dimensional (2D) ultrasound images and has sampling errors thus some cancers can be missed from the standard 2D image-guided biopsy. In this study, an FDA-approved ultrasound device will be used to obtain three-dimensional (3D) images of the prostate from a commercially available ultrasound scanner. The clinician can use the 3D images to guide biopsy, record the core location of the biopsy sites, and perform re-biopsy to the same sites in a patient follow-up examination. This system can also use images from magnetic resonance imaging (MRI) or positron emission tomography (PET) and then fuse PET or MR images with 3D ultrasound images to guide the needle to a suspicious tumor target as seen on MRI or PET. We think that this fusion targeted biopsy technology will help to improve the accuracy of the current systematic biopsy approach for prostate cancer detection.