High-Resolution 3-T Endorectal Prostate MRI: A Multireader Study of Radiologist Preference and Perceived Interpretive Quality of 2D and 3D T2-Weighted Fast Spin-Echo MR Images.

OBJECTIVE: The goal of this study was to compare the perceived quality of 3-T axial T2-weighted high-resolution 2D and high-resolution 3D fast spin-echo (FSE) endorectal MR images of the prostate. MATERIALS AND METHODS: Six radiologists independently reviewed paired 3-T axial T2-weighted high-resolution 2D and 3D FSE endorectal MR images of the prostates of 85 men in two sessions. In the first session (n = 85), each reader selected his or her preferred images; in the second session (n = 28), they determined their confidence in tumor identification and compared the depiction of the prostatic anatomy, tumor conspicuity, and subjective intrinsic image quality of images. A meta-analysis using a random-effects model, logistic regression, and the paired Wilcoxon rank-sum test were used for statistical analyses. RESULTS: Three readers preferred the 2D acquisition (67-89%), and the other three preferred the 3D images (70-80%). The option for one of the techniques was not associated with any of the predictor variables. The 2D FSE images were significantly sharper than 3D FSE (p < 0.001) and significantly more likely to exhibit other (nonmotion) artifacts (p = 0.002). No other statistically significant differences were found. CONCLUSION: Our results suggest that there are strong individual preferences for the 2D or 3D FSE MR images, but there was a wide variability among radiologists. There were differences in image quality (image sharpness and presence of artifacts not related to motion) but not in the sequences' ability to delineate the glandular anatomy and depict a cancerous tumor.

Correlation of endorectal 2D JPRESS findings with pathological Gleason scores in prostate cancer patients.

To determine the metabolite ratios of (Cho + Cr)/Cit and (Cho + Cr)/Spm in patients with two ranges of pathological Gleason scores, namely (3 + 4) and (4 + 3). By using the localized two-dimensional (2D) J-resolved spectroscopy (JPRESS) technique, the metabolites ratios can be calculated and correlated with prostate cancer aggressiveness. A total of 24 patients who underwent endorectal 2D JPRESS between April 2006 and July 2007 were included in this study. The 2D JPRESS voxel was localized predominantly in the peripheral zone suspected for malignancy based on pathology. Using the metabolites such as total choline (Cho), creatine (Cr), spermine (Spm) and citrate (Cit), the ratios (Cho + Cr)/Cit and (Cho + Cr)/Spm were calculated. In 14 prostate cancer patients who had a final pathologic Gleason scores of i) (3 + 4 = 7, n = 7) and ii) (4 + 3 = 7, n = 7), the metabolite ratios (mean +/- SD) of (Cho + Cr)/Cit and (Cho + Cr)/Spm were calculated using the 2D JPRESS spectra as follows: i) (1.48 +/- 0.83) and (1.59 +/- 0.73); ii) (2.90 +/- 0.94) and (2.71 +/- 1.47), respectively. Higher percentage of aggressive disease correlates with higher metabolites ratio. Our pilot study suggests that 2D JPRESS can be reliably evaluated in a clinical setting using an endorectal coil. In addition to the citrate ratio, the spermine ratio also correlates with pathology based Gleason score.

Fine-tuning robot-assisted radical prostatectomy planning with MRI.

OBJECTIVES: Robot-assisted radical prostatectomy (RARP) has now become the most common surgical treatment option for prostate cancer (CaP). Clinicopathologic data (i.e., biopsy, digital rectal exam, prostate specific antigen level) and patient-specific factors (e.g., age, erectile function, co-morbidities) are the primary sources of information that urologists use for counseling and treatment decision making. Magnetic resonance imaging (MRI) has evolved along a similar temporal arc to RARP, with increased utilization and precision over the past decade. MRI prior to RARP provides multifaceted adjunctive information, including enhancement of locoregional staging, delineation of spatial anatomic information, and identification of aberrant anatomy, all of which aid in patient treatment counseling and operative planning. This article is designed for urologic surgeons who perform RARP, with the aim of providing a review of prostate MRI imaging and highlighting findings which may specifically alter the operation. METHODS AND MATERIALS: A review of the literature was performed, focusing on the most recent publications. RESULTS: MRI imaging of the prostate has become increasing accurate for the identification, localization, and characterization of CaP lesions. In addition to tumor-specific information, a number of intra- and extra-prostatic findings are consistently identified on MRI which may impact RARP. CONCLUSIONS: MRI provides important information which may alter RARP.

Diffusion tensor magnetic resonance tractography of the prostate: feasibility for mapping periprostatic fibers.

OBJECTIVE: To evaluate the feasibility of diffusion tensor imaging (DTI) tractography of the prostate for mapping of periprostatic neurovascular anatomy. METHODS: Eight men with prostate cancer scheduled to undergo nerve-sparing robot-assisted radical prostatectomy (RARP) underwent endorectal multiparametric magnetic resonance imaging (MRI) of the prostate with DTI. Tract mapping was accomplished by positioning spherical regions of interest contiguously along the prostatic capsule at the prostatic apex, midgland, and base. RESULTS: DTI tractography of the prostate effectively visualized periprostatic fiber tract anatomy. There was no significant correlation between total tract number and prostate size, however (Spearman's coefficient = 0.33, P = .42). Variation in tract distribution existed. The total fiber mass was highest in the lower prostate hemisphere at the base of the prostate (mean = 36.9 vs 21.1, P = .0004) and in the upper hemisphere at the apex (mean = 41.6 vs 57.9, P = .006). CONCLUSION: DTI tractography successfully visualized fiber tracts around the prostate. Gold standard anatomic correlation is needed.