Three-dimensional US of the prostate: early experience

To assess the feasibility of using a three-dimensional (3D) endorectal transducer at ultrasonography (US) in the prostate gland in a clinical setting.

Sixteen patients underwent 3D imaging of the prostate gland with a 3D endorectal probe following conventional two-dimensional (2D) US and prior to prostatic biopsy. Image acquisition was performed as a volume of data with nearly immediate reconstruction and simultaneous display of sectional anatomy in three orthogonal planes--sagittal plane, transverse or coronal plane, or any arbitrary oblique plane. Images were evaluated for presence of focal lesions, glandular volume, visualization of lateral and anterior portions of the gland, and extraglandular extension of tumor.

Three-dimensional US allowed better visualization of the gland and focal lesions, especially on the coronally reconstructed images, which were judged superior to the sagittally or transversely reconstructed images for interpretation in 50% of the patients. Prostatic volumes obtained from 3D US were consistently smaller than volumes obtained from 2D US (20% difference, P = .006). Three-dimensional US was superior to 2D US in depicting tumor presence (nine of 10 right hemispheres, three of eight left hemispheres) and extraglandular extent of disease (three of five hemispheres).

Three-dimensional endorectal prostatic US appears to be clinically feasible and easy to perform. Added anatomic information from the coronal plane may allow better depiction of tumors and extraglandular spread than is possible with current 2D techniques.