T2-weighted MR imaging of prostate cancer: multishot echo-planar imaging vs fast spin-echo imaging

The aim of the present study was to assess the performance of pre-biopsy T2-weighted MR imaging using multishot echo-planar imaging (EPI) sequence for visualization of prostate cancer and to compare image quality with that of fast spin-echo (FSE) sequence. Thirty-nine patients with suspected prostate cancer and one healthy male volunteer were examined on a 1.5-T MR scanner equipped with a pelvic phased-array coil. Axial MR images were obtained using multishot EPI sequence with a multishot number of 16 and FSE sequence without fat suppression. Paired EPI and FSE images were independently evaluated by three radiologists. Furthermore, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between EPI and FSE images of 12 pathologically proven lesions of prostate cancer. Delineation of the periprostatic venous plexus, prostate zonal anatomy, and seminal vesicle on EPI was graded to be superior/inferior to FSE in 15.8/0, 14.6/0, and 21.5/4.3% of cases, respectively. On the other hand, delineation of the neurovascular bundle was superior/inferior to FSE in 2.6/13.2% of cases. The SNR and CNR of prostate cancer on EPI were significantly higher than those on FSE (7.99+/-2.51 vs 3.36+/-0.58, p<0.0001, and 5.51+/-2.02 vs 2.21+/-0.79, p<0.0001, respectively). In conclusion, multishot EPI has higher quality of contrast resolution for imaging of prostate cancer compared with FSE and would have the potential usefulness in the detection of prostate cancer, although these results obtained with a phased-array coil cannot be extrapolated to examinations performed with an endorectal coil.