Endorectal Magnetic Resonance Imaging Research Articles

Prototype Description and Ex Vivo Evaluation of a System for Combined Endorectal Magnetic Resonance Imaging and In-Bore Biopsy of the Prostate.

We describe early ex vivo proof-of-concept testing of a novel system composed of a disposable endorectal coil and converging multichannel needle guide with a reusable clamp stand, embedded electronics, and baseplate to allow for endorectal magnetic resonance (MR) imaging and in-bore MRI-targeted biopsy of the prostate as a single integrated procedure. Using prostate phantoms imaged with standard T 2 -weighted sequences in a Siemens 3T Prisma MR scanner, we measured the signal-to-noise ratio in successive 1-cm distances from the novel coil and from a commercially available inflatable balloon coil and measured the lateral and longitudinal deviation of the tip of a deployed MR compatible needle from the intended target point. Signal-to-noise ratio obtained with the novel system was significantly better than the inflatable balloon coil at each of five 1-cm intervals, with a mean improvement of 78% ( P < 0.05). In a representative sampling of 15 guidance channels, the mean lateral deviation for MR imaging-guided needle positioning was 1.7 mm and the mean longitudinal deviation was 2.0 mm. Our ex vivo results suggest that our novel system provides significantly improved signal-to-noise ratio when compared with an inflatable balloon coil and is capable of accurate MRI-guided needle deployment.

Seminal Vesicle Cyst: A Rarecase Report

Seminal vesicle cysts are unusual but treatable causes of lower urinary tract symptoms.Transrectal ultrasonography is a good method for initial evaluation of seminal vesicle cysts. Endorectal magnetic resonance imaging should be reserved for the cases whose ultrasonographic results are not conclusive. Treatment should be restricted to symptomatic patients. Transvesical approach and laparoscopy in the hands of an experienced urologist are the best methods for resection of seminal vesicle cysts. In this article, a case of congenital seminal vesicle cysts is presented and the clinical symptoms, diagnosis, and management are discussed. Bangladesh Journal of Urology, Vol. 22, No. 2, July 2019 p.206-209

Climacturia After Radical Prostatectomy: MRI-Based Predictors

BackgroundAfter radical prostatectomy (RP), climacturia is a prevalent and distressing problem. To date, no specific predictors have been identified. AimIn this analysis, we sought to find associated pelvic magnetic resonance imaging (MRI) parameters. MethodsWe identified all men in our departmental database who (i) had climacturia post-RP, ≥3 episodes; (ii) underwent a pre-RP endorectal MRI; (iii) had no radiation or androgen deprivation therapy (ADT). Soft tissue and bony dimensions were measured by 2 raters blinded to clinical and pathological data. OutcomesMRI parameters included the following: maximum height, width, and depth of prostate, prostate volume, urethral width and length, lower conjugate of pelvis, bony femoral width, outer and inner levator distances and thickness. Point-biserial correlations were run on univariate associations. Logistic regression was used for the multivariable model. Results194 consecutive pre-RP MRI studies were reviewed (56 men with and 138 without climacturia). Mean age was 60 ± 7 years, average time post-RP at assessment, 7 ± 7 months. Of MRI parameters, urethral width (r = 0.13, P = .03) and lower conjugate (r = 0.12, P = .05) were associated with presence of persistent climacturia. 2 others met criteria for multivariable analysis, prostate depth and outer levator distance. Of the non-MRI parameters, none were significantly related to climacturia and only body mass index (BMI) met criteria for multivariable analysis. On multivariable analysis, only urethral width was associated with climacturia (OR = 1.23, 95% CI: 1.01–1.49, P = .04); the wider the urethra, greater the chance of climacturia. Clinical ImplicationsImproved ability to predict the occurrence of orgasm-associated incontinence in the preoperative setting. Strengths and LimitationsLimitations include the fact that the MRI endorectal probe may have distorted pelvic tissues during imaging and that our study population size was small. However, prospective data collection, blinded measurements by 2 trained readers, and rigorous statistical analysis should be considered strengths. ConclusionBy identifying preoperative risk factors, such as urethral width on MRI, we may be able to better understand the pathophysiology of this condition and furthermore may permit us to better counsel men regarding this postoperative outcome.Sullivan JF, Ortega Y, Matsushita K, et al. Climacturia After Radical Prostatectomy: MRI-Based Predictors. J Sex Med 2020;17:1723–1728.

Rectal perforation following endorectal prostate MRI: an unexpected complication

BackgroundProstate cancer is a common cancer among men in developed countries. Prostate magnetic resonance imaging (MRI) has been widely employed for early diagnosis of prostate cancer and recommending a treatment plan. The incidence of rectal perforation during endorectal prostate MRI is rare and has never been reported before. Herein, we present a case of rectal perforation after a prostate MRI examination that was subjected to emergency surgical intervention because of the acute presentation of generalized peritonitis. Patients with systemic comorbidities are reportedly at greater risks of encountering colonoscopic perforation. Endorectal prostate MRI is a safe diagnostic modality, but inadequate lubrication of the endorectal coil or over-insufflation of the balloon during the procedure may also lead to serious complications such as hollow organ perforation. Early surgery will be necessary should peritoneal symptoms persist.Case presentationIn 2015, a 56-year-old man came to our ER due to acute abdominal pain after he finished his MRI exam. The exam indicated diffuse tenderness over his abdomen and at the ER, his abdominal CT (computerized tomography) was checked. The images revealed extraluminal air in the perirectal fat and the pneumoperitoneum. In response, exploratory laparotomy, simple closure of rectal perforation, and loop-S colostomy were performed and the patient was discharged 1 month after operation.ConclusionsProstate MRI is a secure procedure with few complications. Clinicians must keep in mind the possibility of perforation when using ultrasound probe. Hollow organ perforation can result in serious morbidity or death. As a result, patients need to be informed of the complications of prostate MRI. When performing the procedure, clinicians must be cautioned about the potential problems for patients with high-anesthetic risk.

Diagnostic capacities of endorectal magnetic resonance imaging in the staging of prostate cancer

Diagnostic capacities of endorectal magnetic resonance imaging in the staging of prostate cancer

Correlation Between Endorectal Ultrasound and Magnetic Resonance Imaging for Predicting the Circumferential Resection Margin in Patients With Mid-Low Rectal Cancer Without Preoperative Chemoradiotherapy.

To assess the correlation between endorectal ultrasound (ERUS) and magnetic resonance imaging (MRI) in predicting the circumferential resection margin (CRM) status of patients with mid-low rectal cancer without preoperative chemoradiotherapy. Twenty patients with rectal cancer who did not receive preoperative chemoradiotherapy and underwent ERUS and MRI examinations before total mesorectal excision from May 2018 to April 2019 were included in this study. The patient and tumor characteristics, lymph nodes, tumor stages, ERUS and MRI predictors of the CRM status, and postoperative pathologic results were recorded. The closest distance between the deepest portion of lesion invasion and the mesorectal fascia was independently measured on MRI and ERUS images by 2 observers. The observers were blinded to the pathologic results. Measurements from ERUS and MRI were compared. The mean distance between the distal edge of the lesion and the anal verge was 5.7 cm (range, 3.1-8.1 cm). The ERUS and pathologic evaluations of CRM involvement were consistent in 90% of the cases. The MRI and pathologic evaluations of CRM involvement were concordant in 95% of the cases. The Cohen κ coefficient of ERUS and MRI was 0.608 (P = .007). The correlation coefficient of ERUS and MRI for assessing the closest distance from the edge of cancer invasion to the mesorectal fascia was 0.99 (P = .0005). Endorectal ultrasound and MRI assessments of the preoperative CRM status appear to be highly consistent. Endorectal ultrasound can be used as a complementary tool with MRI to predict the CRM status of patients with mid-low rectal cancer without preoperative chemoradiotherapy.

Re: Mechanism of Action of the Transobturator Sling for Post-Radical Prostatectomy Incontinence: A Multi-Institutional Prospective Study Using Dynamic Magnetic Resonance Imaging.

No AccessJournal of UrologyUrological Survey1 Jul 2019Re: Mechanism of Action of the Transobturator Sling for Post-Radical Prostatectomy Incontinence: A Multi-Institutional Prospective Study Using Dynamic Magnetic Resonance Imaging Alan J. WeinMD, PhD (hon) Alan J. WeinAlan J. Wein More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000277AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Re: Mechanism of Action of the Transobturator Sling for Post-Radical Prostatectomy Incontinence: A Multi-Institutional Prospective Study Using Dynamic Magnetic Resonance Imaging." The Journal of Urology, 202(1), p. 37 Suggested Reading : Anatomy of radical prostatectomy as defined by magnetic resonance imaging. J Urol 1998; 159: 2148. Link, Google Scholar : Urinary continence after radical retropubic prostatectomy: relationship with membranous urethral length on preoperative endorectal magnetic resonance imaging. J Urol 2002; 168: 1032. Link, Google Scholar © 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 202Issue 1July 2019Page: 37-37 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alan J. Wein More articles by this author Expand All Advertisement Loading ...

Endorectal ultrasound and magnetic resonance imaging for staging of early rectal cancers: how well does it work in practice?

Background: Rectal tumor treatment strategies are individually tailored based on tumor stage, and yield different rates of posttreatment morbidity, mortality, and local recurrence. Therefore, the accuracy of pretreatment staging is highly important. Here we investigated the accuracy of staging by magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) in a clinical setting.Material and methods: A total of 500 patients were examined at the rectal cancer outpatient clinic at Haukeland University Hospital between October 2014 and January 2018. This study included only cases in which the resection specimen had a histopathological staging of adenoma or early rectal cancer (pT1–pT2). Patients with previous pelvic surgery or preoperative radiotherapy were excluded. The 145 analyzed patients were preoperatively examined via biopsy (n = 132), digital rectal examination (n = 77), rigid rectoscopy (n = 127), ERUS (n = 104), real-time elastography (n = 96), and MRI (n = 84).Results: ERUS distinguished between adenomas and early rectal cancer with 88% accuracy (95% CI: 0.68–0.96), while MRI achieved 75% accuracy (95% CI: 0.54–0.88). ERUS tended to overstage T1 tumors as T2–T3 (16/24). MRI overstaged most adenomas to T1–T2 tumors (18/22). Neither ERUS nor MRI distinguished between T1 and T2 tumors.Conclusions: In a clinical setting, ERUS differentiated between benign and malignant tumors with high accuracy. The present findings support previous reports that ERUS and MRI have low accuracy for T-staging of early rectal cancer. We recommend that MRI be routinely combined with ERUS for the clinical examination of rectal tumors, since MRI consistently overstaged adenomas as cancer. In adenomas, MRI had no additional benefit for preoperative staging.

Membranous urethral length and pelvic anatomical structures as predictors of continence outcome after robot-assisted radical prostatectomy

Introduction: Aim of our study was to determine whether preoperative prostate/pelvic anatomical structures predict continence recovery after robot-assisted radical prostatectomy (RARP). Materials and Methods: Between January 2012 and March 2016, 439 prostate cancer (PCa) patients with normal preoperative continence were retrospectively included. Anatomical prostate structures were measured on endorectal preoperative Magnetic Resonance Imaging. The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) was used to assess urinary incontinence (UI). Cox analysis was used to determine predictive factors for early continence recovery. Finally a binary logistic regression analysis was performed. Results: At a median follow up of 12.1 months 50.8% of men reported UI. In the Cox multivariate analysis longer membranous urethral length (MUL; P < 0.0001; OR 1.309; CI 1.211, 1.415) and shorter inner levator distance (ILD; P < 0.0001; OR 0.904; CI 0.85, 0.961) were predictors of earlier continence recovery. In the multivariate binary logistic regression analysis longer MUL and shorter ILD were independent predictors of continence outcome. Conclusions: Preoperative longer MUL and shorter ILD, independently improve continence recovery after RARP. These measurements could be used to identify patients at high risk of UI.

Endorectal MR imaging of prostate cancer: Evaluation of tumor capsular contact length as a sign of extracapsular extension

ObjectiveTo evaluate the length of contact between dominant tumor foci and the prostatic capsule as a sign of extracapsular extension at endorectal multiparametric MR imaging. Materials and methodsWe retrospectively identified 101 patients over a three-year interval who underwent endorectal multiparametric prostate MR imaging prior to radical prostatectomy for prostate cancer. Two readers identified the presence of dominant tumor focus (largest lesion with PI-RADS version 2 score of 4 or 5), and measured the length of tumor capsular contact and likelihood of extracapsular extension by standard criteria (1–5 Likert scale). Results were analyzed using histopathological review as reference standard. ResultsExtracapsular extension was found at histopathological review in 27 patients. Reader 1 (2) identified dominant tumor in 79 (73) patients, with mean tumor capsular contact length of 18.2 (14.0) mm. The area under the receiver operating characteristic curve for identification of extracapsular extension by tumor capsular contact length was 0.76 for reader 1 and 0.77 for reader 2, with optimal discrimination at values of 18 mm and 21 mm, respectively. In the subset of patients without obvious extracapsular extension by standard criteria (Likert scores 1–3), corresponding values were 0.74 and 0.66 with optimal thresholds of 24 and 21 mm. ConclusionLength of contact between the dominant tumor focus and the capsule is a moderately useful sign of extracapsular extension at endorectal multiparametric prostate MR imaging, including the subset of patients without obvious extracapsular extension by standard criteria, with optimal discrimination at threshold values of 18 to 24 mm.

Preoperative Stating of Pelvic Lymph Nodes in Prostate Cancer Patients via Endorectal Magnetic Resonance Imaging.

The aim of this study was to evaluate the diagnostic sensitivity, specificity and accuracy of endorectal magnetic resonance imaging (e-MRI), as a preoperative staging modality in the diagnosis of lymph node metastasis (LNM) in patients with prostate cancer (PCa). Retrospectively, we analyzed data from N=168 patients who underwent radical prostatectomy (RP) between 2004 and 2013 at two tertiary medical centres. Prior to RP all patients underwent an e-MRI. Inclusion criteria were: PSA levels >20 ng/ml or Gleason score >7. Examinations were performed on a closed 1.0-T system combined with an endorectal body phased-array coil, imaging results were correlated with histopathology. 10.7% (N=18 patients) had histologically-proven LNM. e-MRI was true-positive in N=6 (33.3%) and false-negative N=12 patients (66.6%). N=150 (89.3%) patients without LNM e-MRI were true-negative in 96% and false-positive in 4%. Sensitivity was 96%, specificity was 33%, accuracy was 64.5%. e-MRI can be considered a useful preoperative staging modality in diagnosis of LNM.

Patterns of Benign Prostate Hyperplasia Based on Magnetic Resonance Imaging Are Correlated With Lower Urinary Tract Symptoms and Continence in Men Undergoing a Robot-assisted Radical Prostatectomy for Prostate Cancer

To investigate the association between benign prostatic hyperplasia (BPH) patterns, classified by magnetic resonance imaging (MRI), with lower urinary tract symptoms (LUTS) or continence, preoperatively and after robot-assisted laparoscopic radical prostatectomy (RARP). This retrospective study included 49 prostate cancer patients, with prostate size >47 cm3, who underwent an endorectal MRI followed by RARP. Five BPH patterns were identified according to Wasserman, and additional prostate measurements were recorded. LUTS were assessed using the International Prostate Symptom Score and the PR25-LUTS-Questionnaire score. Continence was assessed using the International Consultation of Incontinence Questionnaire-Short Form. BPH pattern 3 (44.9%) was identified most common, followed by pattern 5 (26.6%), 1 (24.5%), and 2 and 4 (both 2%). BPH patterns were significant predictors of preoperative LUTS, with pedunculated with bilateral transition zone (TZ) and retrourethral enlargement (pattern 5) causing more severe symptoms compared with bilateral TZ and retrourethral enlargement (pattern 3) and bilateral TZ enlargement (pattern 1), whereas pattern 3 was additionally associated with more voiding symptoms compared with pattern 1. None of the BPH patterns was predictive of postoperative LUTS and continence. Independent predictors of continence at 12 months were lower preoperative PR25-LUTS score (P = .022) and longer membranous urethral length (P = .025). MRI is useful for classifying patients in BPH patterns which are strongly associated with preoperative LUTS. However, BPH patterns did not predict remnant LUTS or postoperative incontinence. Postoperative continence status was only associated with preoperative LUTS and membranous urethra length.

Results of Dose-adapted Salvage Radiotherapy After Radical Prostatectomy Based on an Endorectal MRI Target Definition Model

To assess the outcome of patients treated with a dose-adapted salvage radiotherapy (SRT) protocol based on an endorectal magnetic resonance imaging (erMRI) failure definition model after radical prostatectomy (RP). We report on 171 relapsing patients after RP who had undergone an erMRI before SRT. 64 Gy were prescribed to the prostatic bed with, in addition, a boost of 10 Gy to the suspected local relapse as detected on erMRI in 131 patients (76.6%). The 3-year biochemical relapse-free survival (bRFS), local relapse-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival were 64.2±4.3%, 100%, 85.2±3.2%, 100%, and 99.1±0.9%, respectively. A PSA value >1 ng/mL before salvage (P=0.006) and an absence of biochemical progression during RT (P=0.001) were both independently correlated with bRFS on multivariate analysis. No significant difference in 3-year bRFS was observed between the boost and no-boost groups (68.4±4.6% vs. 49.7±10%, P=0.251). A PSA value >1 ng/mL before salvage and a biochemical progression during RT were both independently correlated with worse bRFS after SRT. By using erMRI to select patients who are most likely expected to benefit from dose-escalated SRT protocols, this dose-adapted SRT approach was associated with good biochemical control and outcome, serving as a hypothesis-generating basis for further prospective trials aimed at improving the therapeutic ratio in the salvage setting.

Accuracy Validation of an Automated Method for Prostate Segmentation in Magnetic Resonance Imaging.

Three dimensional (3D) manual segmentation of the prostate on magnetic resonance imaging (MRI) is a laborious and time-consuming task that is subject to inter-observer variability. In this study, we developed a fully automatic segmentation algorithm for T2-weighted endorectal prostate MRI and evaluated its accuracy within different regions of interest using a set of complementary error metrics. Our dataset contained 42 T2-weighted endorectal MRI from prostate cancer patients. The prostate was manually segmented by one observer on all of the images and by two other observers on a subset of 10 images. The algorithm first coarsely localizes the prostate in the image using a template matching technique. Then, it defines the prostate surface using learned shape and appearance information from a set of training images. To evaluate the algorithm, we assessed the error metric values in the context of measured inter-observer variability and compared performance to that of our previously published semi-automatic approach. The automatic algorithm needed an average execution time of ∼60s to segment the prostate in 3D. When compared to a single-observer reference standard, the automatic algorithm has an average mean absolute distance of 2.8mm, Dice similarity coefficient of 82%, recall of 82%, precision of 84%, and volume difference of 0.5cm3 in the mid-gland. Concordant with other studies, accuracy was highest in the mid-gland and lower in the apex and base. Loss of accuracy with respect to the semi-automatic algorithm was less than the measured inter-observer variability in manual segmentation for the same task.

Diffusion-weighted endorectal MR imaging at 3T for prostate cancer: correlation with tumor cell density and percentage Gleason pattern on whole mount pathology.

To determine if tumor cell density and percentage of Gleason pattern within an outlined volumetric tumor region of interest (TROI) on whole-mount pathology (WMP) correlate with apparent diffusion coefficient (ADC) values on corresponding TROIs outlined on pre-operative MRI. Men with biopsy-proven prostate adenocarcinoma undergoing multiparametric MRI (mpMRI) prior to prostatectomy were consented to this prospective study. WMP and mpMRI images were viewed using 3D Slicer and each TROI from WMP was contoured on the high b-value ADC maps (b0, 1400). For each TROI outlined on WMP, TCD (tumor cell density) and the percentage of Gleason pattern 3, 4, and 5 were recorded. The ADCmean, ADC10th percentile, ADC90th percentile, and ADCratio were also calculated in each case from the ADC maps using 3D Slicer. Nineteen patients with 21 tumors were included in this study. ADCmean values for TROIs were 944.8±327.4 vs. 1329.9±201.6mm2/s for adjacent non-neoplastic prostate tissue (p<0.001). ADCmean, ADC10th percentile, and ADCratio values for higher grade tumors were lower than those of lower grade tumors (mean 809.71 and 1176.34mm2/s, p=0.014; 10th percentile 613.83 and 1018.14mm2/s, p=0.009; ratio 0.60 and 0.94, p=0.005). TCD and ADCmean (ρ=-0.61, p=0.005) and TCD and ADC10th percentile (ρ=-0.56, p=0.01) were negatively correlated. No correlation was observed between percentage of Gleason pattern and ADC values. DWI MRI can characterize focal prostate cancer using ADCratio, ADC10th percentile, and ADCmean, which correlate with pathological tumor cell density.

Noise-Compensated, Bias-Corrected Diffusion Weighted Endorectal Magnetic Resonance Imaging via a Stochastically Fully-Connected Joint Conditional Random Field Model.

Diffusion weighted magnetic resonance imaging (DW-MR) is a powerful tool in imaging-based prostate cancer screening and detection. Endorectal coils are commonly used in DW-MR imaging to improve the signal-to-noise ratio (SNR) of the acquisition, at the expense of significant intensity inhomogeneities (bias field) that worsens as we move away from the endorectal coil. The presence of bias field can have a significant negative impact on the accuracy of different image analysis tasks, as well as prostate tumor localization, thus leading to increased inter- and intra-observer variability. Retrospective bias correction approaches are introduced as a more efficient way of bias correction compared to the prospective methods such that they correct for both of the scanner and anatomy-related bias fields in MR imaging. Previously proposed retrospective bias field correction methods suffer from undesired noise amplification that can reduce the quality of bias-corrected DW-MR image. Here, we propose a unified data reconstruction approach that enables joint compensation of bias field as well as data noise in DW-MR imaging. The proposed noise-compensated, bias-corrected (NCBC) data reconstruction method takes advantage of a novel stochastically fully connected joint conditional random field (SFC-JCRF) model to mitigate the effects of data noise and bias field in the reconstructed MR data. The proposed NCBC reconstruction method was tested on synthetic DW-MR data, physical DW-phantom as well as real DW-MR data all acquired using endorectal MR coil. Both qualitative and quantitative analysis illustrated that the proposed NCBC method can achieve improved image quality when compared to other tested bias correction methods. As such, the proposed NCBC method may have potential as a useful retrospective approach for improving the consistency of image interpretations.

Endorectal multiparametric MRI of the prostate: incremental effect of perfusion imaging on biopsy target identification

PurposeTo evaluate the incremental effect of perfusion imaging on biopsy target identification at endorectal multiparametric prostate magnetic resonance imaging (MRI). Materials and methodsWe retrospectively 52 patients who underwent endorectal multiparametric prostate MRI for suspected or untreated prostate cancer. Two readers independently identified biopsy targets without and with perfusion images. ResultsReader 1 identified 36 targets without and 39 targets with perfusion imaging (P>.05). The corresponding numbers for reader 2 were 38 and 38, respectively (P=.5). ConclusionPerfusion imaging does not significantly increase the number of biopsy targets identified at endorectal multiparametric prostate MRI.

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.

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. 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. 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. 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.

Endorectal multiparametric 3-tesla magnetic resonance imaging associated with systematic cognitive biopsies does not increase prostate cancer detection rate: a randomized prospective trial.

To investigate prostate cancer (PC) detection rate, employing endorectal multiparametric 3-tesla magnetic resonance imaging (MRI) driving subsequent cognitive systematic prostatic biopsy (CSPB) versus a homogenous group of patients who did not undergo endorectal MRI. A series of patients with a first negative biopsy were enrolled in the study. Patients were randomized into two groups: Group A: patients underwent MRI and subsequent CSPB; Group B: patients that did not undergo MRI. Each patient underwent a 13-core sampling. Patients from Group A had four cores more for each MRI suspected lesion. The cancer detection rate was calculated for each group with regard to possible matches or mismatches between MRI evidence and pathological reports. Two hundred consecutive patients were investigated. Fifty out of 200 (25%) patients had a diagnosis of PC, 24 in Group A and 26 in Group B. In Group A, 67 patients (67%) were positive for suspected lesions at the MRI. The mismatch between MRI findings and the CSPB outcome was 61% with an MRI-driven detection rate of 15%. Group B detection rate was 26% with no significant differences versus Group A (P=NS). Patient discomfort was higher in Group A (82%). The accuracy of CSPB was 41% with a positive predictive value of 22.3%. This rate is lower in high-grade cancers (11.9%). The cost-effectiveness was higher in Group A. Prostate cancer detection rate does not improve by CSPB. The accuracy of CSPB was lower in high-grade PC, and a higher cost was found with CSPB.

Monte Carlo-based noise compensation in coil intensity corrected endorectal MRI.

BackgroundProstate cancer is one of the most common forms of cancer found in males making early diagnosis important. Magnetic resonance imaging (MRI) has been useful in visualizing and localizing tumor candidates and with the use of endorectal coils (ERC), the signal-to-noise ratio (SNR) can be improved. The coils introduce intensity inhomogeneities and the surface coil intensity correction built into MRI scanners is used to reduce these inhomogeneities. However, the correction typically performed at the MRI scanner level leads to noise amplification and noise level variations.MethodsIn this study, we introduce a new Monte Carlo-based noise compensation approach for coil intensity corrected endorectal MRI which allows for effective noise compensation and preservation of details within the prostate. The approach accounts for the ERC SNR profile via a spatially-adaptive noise model for correcting non-stationary noise variations. Such a method is useful particularly for improving the image quality of coil intensity corrected endorectal MRI data performed at the MRI scanner level and when the original raw data is not available.ResultsSNR and contrast-to-noise ratio (CNR) analysis in patient experiments demonstrate an average improvement of 11.7 and 11.2 dB respectively over uncorrected endorectal MRI, and provides strong performance when compared to existing approaches.DiscussionExperimental results using both phantom and patient data showed that ACER provided strong performance in terms of SNR, CNR, edge preservation, subjective scoring when compared to a number of existing approaches.ConclusionsA new noise compensation method was developed for the purpose of improving the quality of coil intensity corrected endorectal MRI data performed at the MRI scanner level. We illustrate that promising noise compensation performance can be achieved for the proposed approach, which is particularly important for processing coil intensity corrected endorectal MRI data performed at the MRI scanner level and when the original raw data is not available.