Biparametric MRI Research Articles

619 - Simple biparametric MRI in detection and ruling out significant prostate cancer in biopsy-naïve men (BIDOC study)

619 - Simple biparametric MRI in detection and ruling out significant prostate cancer in biopsy-naïve men (BIDOC study)

Diagnostic accuracy of biparametric vs multiparametric MRI in clinically significant prostate cancer: Comparison between readers with different experience

BackgroundMRI plays a crucial role to identify men with a high likelihood of clinically significant prostate cancer who require immediate biopsy. The added value of DCE MRI in combination with T2-weighted imaging and DWI is controversial (risks related to gadolinium administration, duration of MR exam, financial burden, effects on diagnostic performance). A comparison of a biparametric and a standard multiparametric MR imaging protocol, taking into account the different experience of the readers, may help to choose the best MR approach regarding diagnostic performance. PurposeTo determine the added value of dynamic contrasted-enhanced imaging (DCE) over T2-weighted imaging (T2-WI) and diffusion weighted imaging (DWI) for the detection of clinically significant prostate cancer, and to evaluate how it affects the diagnostic performance of three readers with different grade of experience in prostate imaging. Materials and methodsEighty-five patients underwent prostate MR examination at 1.5 T MR scanner performed because of elevated prostate-specific antigen level and/or suspicion of prostate cancer at digital rectal examination.Two MR images sets (Set 1 = biparametric, Set 2 = multiparametric) were retrospectively and independently scored by three radiologists with 7, 3 and 1 years of experience in prostate MR imaging respectively, according to PI-RADS v2. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated by dichotomizing reader scores. Receiver operating characteristic (ROC) analysis was performed and areas under the curve (AUCs) were calculated for each reader and image set. A comparison of ROC curves was performed to test the difference between the areas under the ROC curves among the three readers. ResultsThere was no significant difference regarding the detection of clinically significant tumor among the three readers between the two image sets. The AUC for the bi-parametric and multi-parametric MR imaging protocol was respectively 0.68–0.72 (Reader 1), 0.72–0.70 (Reader 2) and 0.60–0.54 (Reader 3). ROC curve comparison revealed no statistically significant differences for each protocol among the most experienced (Reader 1) and the other readers (Readers 2–3). ConclusionThe diagnostic accuracy of a bi-parametric MR imaging protocol consisting of T2-weighted imaging and DWI is comparable with that of a standard multi-parametric imaging protocol for the detection of clinically significant prostate cancer. The experience of the reader does not significantly modify the diagnostic performance of both MR protocols.

Clinical Application of Biparametric MRI Texture Analysis for Detection and Evaluation of High-Grade Prostate Cancer in Zone-Specific Regions.

The purpose of this study was to investigate the performance of biparametric MRI texture analysis (TA) in detecting and evaluating high-grade prostate cancer in zone-specific regions. A retrospective study included 184 consecutively registered biopsy-naive patients in whom prostate cancer was suspected who were undergoing multiparametric prostate MRI. MR images were scored and evaluated by two readers using the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and biparametric MRI TA in separate sessions. Interobserver agreement on PI-RADSv2 score and textural parameters of biparametric MRI was evaluated. The logistic regression model based on TA was built for different zones of the prostate. ROC analysis was used to compare the TA-based model with other parameters alone. The correlation of each parameter with Gleason score of high-grade prostate cancer was also assessed. Reader reliability ranged from moderate to good for PI-RADSv2 (Cohen κ = 0.525-0.616) and from good to excellent for textural metrics (intraclass correlation coefficient, 0.745-0.925). Diagnostic performance was significantly improved by use of the TA-based model (transition zone AUC, 0.87; peripheral zone AUC, 0.89) in comparison with PI-RADSv2 and other texture parameters alone. For the transition zone, entropy had moderate to good correlation with the Gleason score of high-grade prostate cancer (r = 0.562, p = 0.004). In the peripheral zone, entropy (r = 0.614, p = 0.003) and inertia (r = 0.663, p = 0.002) had moderate to good correlations with Gleason score. The results of this clinical study indicate that a TA-based model that includes biparametric MRI can be used for identifying high-grade prostate cancer and that specific parameters extracted from TA may be additional tools for assessing tumor aggressiveness.

Score 3 prostate lesions: a gray zone for PI-RADS v2.

Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) does not offer a precise guidance on the clinical management (biopsy or not biopsy) for PI-RADS v2 score 3 lesions. Lesion volume calculated on biparametric MRI (bpMRI) [T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI)] by introducing a cut-off of 0.5 mL, allows to distinguish the lesions assigned by the multiparametric MRI (mpMRI) to the category PI-RADS v2 score 3 in two subgroups: a) Indolent or low risk lesions with volume <0.5 mL, and b) Significant or high risk lesions with volume ≥0.5 mL. For mpMRI lesions assigned to PI-RADS v2 score 3, we suggest the following management: 1) Subgroup a (low-risk lesion): Clinical surveillance (accurate evaluation of age and clinical informations, periodic monitoring of prostate specific antigen value and repeated bpMRI 1 year later); 2) Subgroup b (high-risk lesion): Targeted biopsy. The proposed management would reduce the use of unnecessary biopsies and increase the diagostic yield of significant prostate cancer of approximately 50% and 30% respectively. These approaches encourage the radiologist to adopt MRI lesion volume to improve PI-RADS v2 and to optimize the management of PI-RADS v2 score 3 lesions.

Is contrast enhancement needed for diagnostic prostate MRI?

Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) provides clinical guidelines for multiparametric magnetic resonance imaging (mpMRI) [T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)] of prostate. However, DCE-MRI seems to show a limited contribution in prostate cancer (PCa) detection and management. In our experience, DCE-MRI, did not show significant change in diagnostic performance in addition to DWI and T2WI [biparametric MRI (bpMRI)] which represent the predominant sequences to detect suspected lesions in peripheral and transitional zone (TZ). In this article we reviewed the role of DCE-MRI also indicating the potential contribute of bpMRI approach (T2WI and DWI) and lesion volume evaluation in the diagnosis and management of suspected PCa.

Biparametric versus Multiparametric MRI with Non-endorectal Coil at 3T in the Detection and Localization of Prostate Cancer.

To assess the sensitivity of biparametric magnetic resonance imaging (bpMRI) with non-endorectal coil in the detection and localization of index (dominant) and non-index lesions in patients suspected of having prostate cancer. We carried-out a retrospective analysis of multiparametric MRI (mpMRI) of 41 patients who underwent radical prostatectomy. Results of MRI for detection and localization of index and non-index lesions were correlated with those of histology. No statistically significant difference in size was seen between tumor lesion at histology and index lesion at MRI. In 41 patients, a total of 131 tumors were identified at histology, while bpMRI (T2-weighted and diffusion-weighted MRI) approach detected 181 lesions. bpMRI gave 27.6% false-positives and 3.3% false-negatives. Sensitivity in lesion detection by bpMRI increased with lesion size assuming high values for lesions ≥10 mm. For bpMRI and mpMRI, the sensitivity for detecting index lesions was the same and equal: 100% in the peripheral zone 97.6% and 94.7% in the entire prostate and transitional zone, respectively. bpMRI can be used alternatively to mpMRI to detect and localize index prostate cancer.

Magnetic resonance imaging of the prostate at 1.5 versus 3.0 T: A prospective comparison study of image quality

ObjectivesThis study prospectively evaluates objective image quality (IQ), subjective IQ, and PI-RADS scoring of prostate MRI at 3.0T (3T) and 1.5T (1.5T) within the same patients. MethodsSixty-three consecutive patients (64±9years) were prospectively included in this non-inferiority trial, powered at 80% to demonstrate a ≤10% difference in signal-to-noise (SNR) and contrast-to-noise ratio (CNR) of T2-weighted and diffusion-weighted imaging (T2WI, DWI) at 1.5T compared to 3T. Secondary endpoints were analysis of subjective IQ and PI-RADS v2 scoring. ResultsAll patients received multi-parametric prostate MRI on a 3T (T2WI, DWI, DCE) and bi-parametric MRI (T2WI, DWI) on a 1.5T scanner using body coils, respectively. SNR and CNR of T2WI were similar at 1.5T and 3T (p=0.7–1), but of DWI significantly lower at 1.5T (p<0.01). Subjective IQ was significantly better at 3T for both, T2WI and DWI (p<0.01). PI-RADS scores were comparable for both field strengths (p=0.05–1). Inter-reader agreement was excellent for subjective IQ assessment and PI-RADS scoring (k=0.9–1). ConclusionProstate MRI at 1.5T can reveal comparable objective image quality in T2WI, but is inferior to 3T in DWI and subjective IQ. However, similar PI-RADS scoring and thus diagnostic performance seems feasible independent of the field strength even without an endorectal coil.

Novel biparametric MRI and targeted biopsy improves risk stratification in men with a clinical suspicion of prostate cancer (IMPROD Trial).

To evaluate the role of a 3T biparametric magnetic resonance imaging (bpMRI), T2 -weighted imaging, and three separate diffusion-weighted imaging acquisitions combined with targeted biopsy (TB) for improving risk stratification of men with elevated prostate-specific antigen (PSA). Between March 2013 and February 2015, 175 men with a clinical suspicion of prostate cancer (PCa) were offered bpMRI (NCT01864135) based on a suspicion of PCa (two repeated PSA measurements in the range 2.5-20.0 ng/ml and/or abnormal digital rectal examination). Men with an equivocal to high suspicion of PCa had two TBs of the dominant lesion using cognitive ultrasound guidance, followed by systematic biopsy (SB). Men with a low to very low suspicion had only SB. In total, 161 (161/175, 92%) prospectively enrolled men completed the trial and were included in the final analyses. The primary endpoint of the trial was the cancer detection rate (CDR) of TB and SB. Clinically significant cancer (SPCa) was defined as Gleason score ≥3 + 4. TB compared with SB had higher CDR for SPCa (45%, 72/161 vs. 39%, 63/161, respectively; P > 0.05) and a lower CDR for Gleason score 3 + 3 (8%, 15/161 vs. 16%, 30/161; P < 0.05). Restricting biopsy to men with equivocal to highly suspicious bpMRI findings would have resulted in a 24% (38/161) reduction in the number of men undergoing biopsy, while missing 4 (2%) with SPCa. All anonymized datasets, including bpMRI reports and follow up information, are freely available on the trial server. Prebiopsy bpMRI and TB in men with a clinical suspicion of PCa improved risk stratification. 1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2017;46:1089-1095.

Biparametric versus multiparametric MRI in the diagnosis of prostate cancer.

BackgroundSince multiparametric magnetic resonance imaging (mp-MRI) of the prostate exceeds 30 min, minimizing the evaluation time of significant (Gleason scores > 6) prostate cancer (PCa) would be beneficial. A reduced protocol might be sufficient for the diagnosis.PurposeTo study whether a short unenhanced biparametric MRI (bp-MRI) matches mp-MRI in detecting significant PCa.Material and MethodsA total of 204 men (median age, 65 years; mean ± SD, 64.1; range 45–75 years; median serum PSA level, 14 ng/mL; range, 2.2–120 ng/mL; median prostate volume, 60 mL; range, 23–263 mL) fulfilled the criteria for being enrolled. They underwent mp-MRI and prostate biopsy from January through June 2014. Of the included patients, 9.3% underwent prostatectomy, 90.7% had TRUS-bx, and 10.8 had MRI-targeted TRUS-bx. Two radiologists separately assessed the mp-MRI examination (T2-weighted [T2W] imaging, diffusion-weighted imaging [DWI], apparent diffusion coefficient map [ADC-map] and dynamic contrast-enhanced imaging [DCE]). Two months later, the bp-MRI version (T2W imaging, DWI, and ADC-map) was evaluated.ResultsReader 1: Assessing mp-MRI: 0 false negatives, sensitivity of 1, and specificity 0.04. Assessing bp-MRI: four false negatives, sensitivity of 0.94, and specificity 0.15. Reader 2: Assessing mp-MRI: five false negatives, sensitivity of 0.93, and specificity 0.16. Assessing bp-MRI: three false negatives, sensitivity of 0.96, and specificity 0.15. Intra-reader agreement Cohen’s Kappa (κ) was 0.87 for reader 1 (95% confidence interval [CI], 0.83–0.92) and 0.84 for reader 2 (95% CI 0.78–0.89).ConclusionBp-MRI is as good as mp-MRI at detecting PCa. A large prospective study seems to be strongly warranted.

Standardizing Biparametric MRI to Simplify and Improve Prostate Imaging Reporting and Data System, Version 2, in Prostate Cancer Management.

Standardizing Biparametric MRI to Simplify and Improve Prostate Imaging Reporting and Data System, Version 2, in Prostate Cancer Management.

Reply to "Standardizing Biparametric MRI to Simplify and Improve Prostate Imaging Reporting and Data System, Version 2, in Prostate Cancer Management".

Reply to "Standardizing Biparametric MRI to Simplify and Improve Prostate Imaging Reporting and Data System, Version 2, in Prostate Cancer Management".

Contrast-ing opinions: biparametric versus multiparametric prostate MRI.

Dear Editor, I note the short communication by Turkbey and Choyke providing a succinct summary of the updated PI-RADS system for prostate MRI acquisition and interpretation in the September-October 2015 issue of Diagnostic and Interventional Radiology. (1). An interesting argument has also been presented against the routine use of dynamic contrast-enhanced (DCE) sequences suggested therein for multiparametric magnetic resonance imaging (mpMRI) evaluation of the prostate (2). The “multi” of mpMRI has never been strictly defined but is taken to mean the addition of functional sequence(s) to standard anatomical imaging. In reflecting the evolving diagnostic role of mpMRI, the recently updated Prostate Imaging Reporting and Data System (PIRADS) 2.0 removed the recommendation for routine magnetic resonance spectroscopy and reduced the role of DCE. The limitations of DCE have been well set out by the authors, namely the cost and its limited specificity. Unlike in breast MRI, DCE curve-typing is limited because most tumors demonstrate a type II curve (3) and a number of benign prostate conditions such as prostatitis and benign prostatic hyperplasia can demonstrate a Type III curve. Essentially the updated recommendations relegate the role of DCE to that of assessment of indeterminate lesions in the peripheral zone, and even then there must be a corresponding abnormality on another sequence. However, before dismissing DCE completely we need to appreciate the advantages it may bring. Contrast is often essential in the follow-up of patients undergoing ablative focal therapy procedures. Furthermore, DCE has a role to play when there is a technical failure of diffusion-weighted imaging which, aside from known presence of metalwork, may be difficult to prospectively predict. Indeterminate lesions may be seen in up 30% of studies using the old guidelines (4), and it has been suggested that the updated version will increase the tendency of radiologists to call PIRADS-3 lesions (5). In the absence of employing a patient-recall system, or having a supervising radiologist make on-table decisions for giving contrast, these are valid reasons for the routine use of DCE. At our institution we use DCE (45-minute time slot) for the initial, baseline MRI and biparametric (bp) MRI for follow-up in active surveillance (30 minutes), thus, three patients can be scanned using the latter protocol for every two using the former. Given the increasing demand for prostate MRI, this potentially has a significant impact on work flows aside from the ancillary costs of DCE. The use of bpMRI as a quick “screening” examination in biopsy-naive patients therefore becomes an attractive proposition. However, the current case for bpMRI is based on anecdotal and limited retrospective evaluations; hopefully future prospective randomized studies can help resolve the issue.

Prenatal Diagnosis of Renal Failure by Fetal Biparametric Magnetic Resonance Imaging

AbstractCongenital anomalies of the kidneys and urinary tract represent 93% of all prenatally diagnosed malformations. In the reported case, fetal Biparametric MRI (Bp-MRI) by morphologic (T1- and T2-weighted) and functional diffusion-weighted (DW) images allowed both diagnosis of congenital anomalies (e.g., hydrometrocolpos with septate vagina and uterus didelphys), and associated malfunction of kidneys by means of measurement of cortical and medullary apparent diffusion coefficient (ADC) values.

The current and future role of magnetic resonance imaging in prostate cancer detection and management.

PurposeAccurate detection of clinically significant prostate cancer (PC) and correct risk attribution are essential to individually counsel men with PC. Multiparametric MRI (mpMRI) facilitates correct localization of index lesions within the prostate and MRI-targeted prostate biopsy (TPB) helps to avoid the shortcomings of conventional biopsy such as false-negative results or underdiagnosis of aggressive PC. In this review we summarize the different sequences of mpMRI, characterize the possibilities of incorporating MRI in the biopsy workflow and outline the performance of targeted and systematic cores in significant cancer detection. Furthermore, we outline the potential of MRI in patients undergoing active surveillance (AS) and in the pre-operative setting.Materials and methodsAn electronic MEDLINE/PubMed search up to February 2015 was performed. English language articles were reviewed for inclusion ability and data were extracted, analyzed and summarized.ResultsTargeted biopsies significantly outperform conventional systematic biopsies in the detection of significant PC and are not inferior when compared to transperineal saturation biopsies. MpMRI can detect index lesions in app. 90% of cases as compared to prostatectomy specimen. The diagnostic performance of biparametric MRI (T2w + DWI) is not inferior to mpMRI, offering options to diminish cost- and time-consumption. Since app 10% of significant lesions are still MRI-invisible, systematic cores seem to be necessary. In-bore biopsy and MRI/TRUS-fusion-guided biopsy tend to be superior techniques compared to cognitive fusion. In AS, mpMRI avoids underdetection of significant PC and confirms low-risk disease accurately. In higher-risk disease, pre-surgical MRI can change the clinically-based surgical plan in up to a third of cases.ConclusionsmpMRI and targeted biopsies are able to detect significant PC accurately and mitigate insignificant PC detection. As long as the negative predictive value (NPV) is still imperfect, systematic cores should not be omitted for optimal staging of disease. The potential to correctly classify aggressiveness of disease in AS patients and to guide and plan prostatectomy is evolving.

Diagnostic value of biparametric MRI as an adjunct to PSA-based detection of prostate cancer.

193 Background: To determine the diagnostic yield of analyzing a fast, cost-conscious biparametric (T2 and diffusion-weighted) MRI (B-MRI) for prostate cancer (PCa) detection as an adjunct to to standard digital rectal exam (DRE) and prostate specific antigen (PSA)-based screening. Methods: Review of patients who were enrolled in a trial to undergo MP-MRI and MR/US fusion-guided prostate biopsy at our institution identified 143 men who underwent MP-MRI in addition to standard DRE and PSA-based PCa screening prior to any other prior prostate biopsy sessions. Patient demographics, DRE staging, PSA, PSA density (PSAD), and B-MRI findings were assessed for association with PCa detection on biopsy. Results: Men with detected PCa tended to be older, with higher PSA, higher PSAD, and increased number of screen positive lesions (#SPL) on B-MRI. B-MRI performed well for the detection of PCa with an area under the curve (AUC) of 0.80 (compared to 0.66 and 0.74 for PSA and PSAD). We derived PSA and MRI-based combined screening formulas for detection of PCa with optimized thresholds. (1) for PSA and B-MRI: PSA + 6 x (#SPL) &gt; 14 and (2) for PSAD and B-MRI: 14 x (PSAD) + (#SPL) &gt; 4.25. Area under the curve for equations 1 and 2 were 0.83 and 0.87 and overall accuracy of PCa detection was 79% in both models. Furthermore, the model integrating PSA with #SPL on B-MRI, was much more efficient at maximally identifying men with Gleason 7 or higher disease compared to PSA-screening alone. Use of model combining PSAD and MRI, the number of bGS 7 or higher cancers that were missed was minimized. Overall, combined use of PSA or PSAD coupled with B-MRI #SPL improved the true positive yield of identifying men with bGS 7 or higher while minimizing the false positive number of men identified as “screen-positive,” but with no cancer on biopsy. Conclusions: Number of positive lesions on B-MRI outperforms PSA alone in detecting PCa, supporting the use of this limited, non-contrast MRI as a potential adjunct tool in PCa screening. Furthermore, this imaging criteria coupled as an adjunct with PSA and PSAD, provides even more accuracy in detecting clinically-significant PCa.