Endorectal Surface Coil Magnetic Resonance Research Articles

Local staging of prostate cancer with endorectal surface coil MR imaging in a mid-field magnetic system

To investigate the accuracy of endorectal surface coil magnetic resonance imaging (ecMRI) in a 1.0-T magnetic field for the local staging of prostate cancer, 25 patients were studied. In 14 Stages T1 and T2 tumors, 11 were correctly identified and 3 were overstaged. In 11 Stage T3 neoplasms, ecMRI was accurate in 7 cases, and the other 4 were understaged. The overall accuracy of ecMRI in 1.0 T was 72% and that was comparable to the reported accuracy of this technique in high-field systems.

Endorectal MRI of Prostate Cancer: Comparison with Findings on Radical Prostatectomy

Purpose : To assess the accuracy of magnetic resonance (MR) imaging using an endorectal surface coil ineval-uation of local lesions of prostate carcinoma. Materials and Methods : Twenty patients with surgically provenprostate carcinoma underwent MR imaging using a 1.5T unit and an endorectal surface coil made at the Asan MedicalCenter. T1-weighted images in the axial plane and T2-weighted images in the axial, coronal, and sagittal planeswere obtained in all patients. We divided the prostate gland into right and left lobe, then determined thelocation of carcinoma within it, as well as capsular penetration and seminal vesicle invasion. MR images werecompared with surgical specimens. Results : MR imaging using an endorectal surface coil accurately demonstratedthe staging of prostate carcino-ma in 60% of patients (12/20), but with regard to the location of carcinoma withinthe prostate gland, capsular penetration, and seminal vesicle invasion, only nine cases (45%) showed completeagreement between en-dorectal surface coil MR images and pathologic findings. The accuracy of localizing thecarcinoma within the prostate gland, capsular penetration, and seminal vesicle invasion were 65%(13/20),70%(14/20), and 90%(18/20), respectively. Conclusion : MR imaging using an endorectal surface coil for thelocalization of prostate carcinoma and periprostatic tissue invasion showed a low degree of accuracy. Morespecific imaging findings are therefore needed.

Evaluation of regional extension of rectal carcinoma comparison of endorectal ultrasound (EUS) with endorectal surface coil magnetic resonance imaging (MRI)

Evaluation of regional extension of rectal carcinoma comparison of endorectal ultrasound (EUS) with endorectal surface coil magnetic resonance imaging (MRI)

A multivariable analysis of clinical factors predicting for pathological features associated with local failure after radical prostatectomy for prostate cancer

Purpose : A multivariate analysis is used to determine the predictive value of pretreatment clinical indicators on pathologic features associated with local failure after radical prostatectomy in patients with prostate cancer. Methods and Materials : A retrospective review of the pathologic findings of 235 patients with adenocarcinoma of the prostate treated between 1990 and 1993 with a radical retropubic prostatectomy was performed. The preoperative clinical data including the serum prostate specific antigen, clinical stage, Gleason sum, and endorectal magnetic resonance scan findings are used to identify patients prior to definitive treatment who would be at high risk for having pathologic features associated with local failure at radical prostatectomy. Outcome prediction curves are constructed from a logistic regression multivariate analysis displaying the probability of pathologic involvement of the seminal vesicle, extracapsular disease, or positive surgical margins as a function of the preoperative prostate specific antigen and Gleason sum for the cases when the endorectal magnetic resonance scan is positive, negative, or not included in the multivariate analysis. Results : Factors identified on multivariate analysis as significant predictors of seminal vesicle invasion include endorectal magnetic resonance scan findings ( p < 0.0001), and preoperative prostate specific antigen ( p = 0.017). Endorectal magnetic resonance scan findings ( p = 0.0016), preoperative prostate specific antigen ( p = 0.0002), and Gleason sum ( p < 0.0001) were significant predictors of extracapsular extension and preoperative prostate specific antigen ( p < 0.0001) and Gleason sum ( p = 0.03) were significant predictors of disease extending to the margins of resection. Clinical stage was not a significant predictor ( p > 0.05) of pathologic features associated with local failure on multivariate analysis. As a single modality, endorectal surface coil magnetic resonance imaging was accurate 93%, 69%, and 72% of the time for predicting seminal vesicle invasion, transcapsular disease, and final pathologic stage, respectively. Failure to recognize microscopic penetration of the capsule found at the time of pathologic evaluation in a prostate gland with a grossly intact capsule accounts for the majority (70%) of the staging inaccuracies. Conclusions : The use of the endorectal surface coil magnetic resonance scan findings in conjunction with both the serum prostate specific antigen and Gleason sum improves the clinical accuracy of predicting those patients at high risk for clinically unsuspected extraprostatic disease. In particular, for the subgroup of patients with moderately elevated prostate specific antigen (> 10–20 ng/mL) and intermediate grade clinically organ confined prostate cancer [Gleason sum: 5–7] where the specificity of these tests to predict for occult extraprostatic disease is suboptimal, the additional information obtained from the endorectal coil magnetic resonance scan allows the physician to definitively subgroup these patients into low and high risk for seminal vesicle invasion or transcapsular disease.

Use of Endorectal Surface Coil Magnetic Resonance Imaging for Local Staging of Prostate Cancer

A total of 111 patients with clinically localized prostate cancer (stage A or B) underwent endorectal surface coil magnetic resonance imaging (MRI) for preoperative staging of the disease. Of the patients 43 with advanced disease on endorectal surface coil MRI (33 with stage C and 10 with stage D disease) received alternative therapy, as did 21 with stage B disease on MRI The overall staging accuracy for the remaining 47 patients was 68%, with a 74% accuracy rate in staging advanced disease and a 91% accuracy rate for depiction of seminal vesicle involvement. Failure to recognize microscopic extracapsular disease was responsible for the majority of staging inaccuracies in this highly select group of patients. Endorectal surface coil MRI provides extremely high resolution images of the prostate and periprostatic structures, and is an exciting new modality for local staging of prostatic carcinoma.

Endorectal surface coil MR imaging of prostatic carcinoma with the inversion‐recovery sequence

The value of inversion-recovery (IR) sequences in the diagnosis and staging of prostatic carcinoma with magnetic resonance (MR) imaging was studied. Twenty-six patients with carcinoma of the prostate were imaged at 1.5 T with an endorectal surface coil and with a variety of IR sequences and a set of spin-echo (SE) sequences for comparison. Ex vivo prostate specimens were imaged again at the same field strength. The two images were correlated with histologic sections. Cancer was identified with MR imaging in 96% of patients. Of the tumors more than 4 mm in diameter, 87% were identified on T2-weighted SE images, whereas only 26% were identified on IR images. However, IR images may be more useful in local staging of carcinoma. Gross capsular infiltration was present in only two patients; however, it was detectable (and excluded in five other patients) by means of IR images. It was not detectable on SE images. The high quality of images obtained with the endorectal coil was confirmed. The authors conclude that addition of the IR sequence to MR imaging with the endorectal coil may improve the usefulness of this examination.

Prostate cancer: local staging with endorectal surface coil MR imaging.

Endorectal surface coil magnetic resonance (MR) imaging was used to stage the local extent of prostate cancer in 22 patients. The endorectal coil images were acquired with a 10-12-cm field of view and a 4-mm section thickness. All pathologic specimens were reviewed by one pathologist. Endorectal surface coil MR imaging was 82% accurate in the differentiation of stage B from stage C cancer. One case was overestimated, and three cases were underestimated. The three underestimated cases consisted of two cases of microscopic capsular invasion and one case of minimal seminal vesicle invasion. In a comparison of retrospective, blinded readings of endorectal coil and body coil images, there was an average improvement in accuracy of 16% in staging prostate cancer with endorectal coil images.