Endorectal MR Research Articles

Local Staging of Prostatic Carcinoma: Comparison of Transrectal Sonography and Endorectal MR Imaging

Local Staging of Prostatic Carcinoma: Comparison of Transrectal Sonography and Endorectal MR Imaging

Local staging of prostatic carcinoma: comparison of transrectal sonography and endorectal MR imaging.

We compared the results of transrectal sonography and endorectal MR imaging in the local staging of prostatic carcinoma. 56 patients (mean age, 61.1 +/- 7.3 years) with the diagnosis of prostate cancer who by transrectal sonography had no evidence of gross extracapsular extension underwent endorectal coil MR imaging prior to radical prostatectomy. Imaging findings prospectively evaluated in each patient were cancer laterality, extracapsular extension, and seminal vesicle invasion. Twenty-one of 56 (38%) patients had extracapsular extension on final pathology. A total of 100 sides and five seminal vesicles were involved with cancer, and 27 sides (21 patients, six with bilateral extracapsular extension) demonstrated extracapsular extension. Imaging results were correlated with step-sectioned, radical prostatectomy pathologic data, and statistical analysis was expressed at a p = .05 level of significance. Retrospective readings of the images were used to construct receiver operating characteristic curves for the detection of extracapsular extension. For tumor laterality, transrectal sonography was compared with endorectal coil MR imaging for sensitivity (70% versus 97%; p < .001), specificity (58% versus 58%), positive predictive value (93% versus 95%) and negative predictive value (18% versus 70%). For extracapsular extension, transrectal sonography was compared with endorectal coil MR imaging for the entire prostate and individually for each side of the prostate. The respective results for sensitivity (48% versus 91%, p < .01 and 37% versus 78%, p < .005), specificity (71% versus 49% and 87% versus 73%), positive predictive value (50% versus 51% and 48% versus 48%), and negative predictive value (69% versus 90% and 81% versus 91%). The receiver operating characteristic analysis of retrospective data demonstrated endorectal coil MR imaging to be superior to transrectal sonography in the detection of extracapsular extension. The small number of seminal vesicles involved by cancer (n = 5) precluded meaningful comparisons between the imaging techniques. Endorectal coil MR imaging is more sensitive but less specific than transrectal sonography for detecting extracapsular extension of carcinoma of the prostate. Both procedures have low positive predictive values yet similarly high negative predictive values when each side of the prostate is assessed independently for extracapsular extension.

Prostate imaging by endorectal coil MR, body helmholtz coil MR and transrectal ultrasound: Which is most useful?

Prostate imaging by endorectal coil MR, body helmholtz coil MR and transrectal ultrasound: Which is most useful?

Evaluation of fat saturation technique for T2-weighted endorectal coil MRI of the prostate

The use of fat suppression has been found to improve tissue contrast and artifact control for performance of body coil MR imaging of the pelvis. The objective of this study was to evaluate whether use of fat suppression confers similar advantages when endorectal coil MR examinations are performed for staging of prostate cancer. Sixty consecutive patients were evaluated with conventional T 1-weighted (TR 600, TE 20) and conventional and fat saturation proton density-/ T 2-weighted (TR 2500, TE 35 80 ) sequences. Thirteen of 60 patients underwent subsequent radical prostatectomy and constituted the study group for which conventional and fat suppressed long TR images were directly compared by three reviewers. Criteria assessed included the relative ability of each sequence to demonstrate zonal distinction, periprostatic venous plexus, fibromuscular stroma, capsule definition, seminal vesicle architecture, tumor conspicuity, capsular penetration and/or seminal vesicle tumor invasion, artifact control, and overall image quality. There was no statistically significant improvement in factors relating to image quality with use of fat saturation. In addition, depiction of the anatomic and pathologic features listed above was not significantly improved for fat-suppressed as compared with conventional endorectal coil images. It is concluded that fat saturation does not result in significant improvement over conventional T 2-weighted images in endorectal MR imaging of the prostate.

Accurate intensity correction for endorectal surface coil MR imaging of the prostate

An accurate technique is developed to correct the intensity variation in the magnetic resonance images acquired with an endorectal surface coil for prostate imaging. The technique relies on reconstructing the in vivo size, shape, and location of the coil during imaging, wherefrom a pixel-by-pixel correction is applied to the coil's sensitivity profile in accordance with the Biot-Savart law. The method is evaluated by a test-object containing multiple layers of beads embedded in gelatine. Qualitatively, the improvement in visualizing regions of interest after corrections is obvious. Quantitatively, the local SNR shows an improvement by a factor of 1.5-2. Several human studies are performed. The technique shows remarkable improvement in visualizing the prostate region.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>