3 Tesla magnetic resonance Imaging of the prostate with combined pelvic phased-array and endorectal coils: Initial experience

Rationale and Objectives. High-resolution magnetic resonance imaging of the prostate at 1.5T has gained acceptance for pretherapeutic staging of prostate cancer. The aim of this study was to evaluate the potential clinical utility of combined pelvic phased-array and endorectal coils at 3T. Materials and Methods. Six volunteers were examined on 1.5T and 3T scanners with pelvic phased-array surface coil combined with a disposable endorectal prostate coil. Results. We were able to acquire T2-W fast spin echo images with 1.5 mm slices, field of view 12, matrix 320 X 192, (voxel size 6.35 mm(3)), with excellent anatomic detail and good T2 contrast. A 1.5 mm axial slice thickness permitted high-quality multiplanar reconstructions with clear visualization of small patho-anatomic structures. Dynamic contrast-enhanced gradient echo images showed excellent spatial resolution (voxel size, 0.38 mm(3)) and temporal resolution. With this level of anatomic information in dynamic images we could clearly distinguish between intracapsular and extracapsular contrast enhancement. Conclusion. Using modified T2-fast spin echo and dynamic contrast-enhanced gradient echo sequences, we obtained whole gland coverage with 35-38 mum(3) resolution, without interfering artifacts, in reasonable acquisition times and staying well below the specific absorption rate guidelines. The high spatial resolution in the axial plane allowed meaningful multiplanar reconstructions. The initial results show the clinical utility of endorectal 3T for the noninvasive evaluation of the prostate with image features and quality not achievable at 1.5 T.