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The high quality of MRI reporting of the prostate is the most critical component of the service provided by a radiologist. Prostate MRI structured reporting with PI-RADS v. 2.1 has been proven to improve consistency, quality, guideline-based care in the management of prostate cancer. There is room for improved accuracy of prostate mpMRI reporting, particularly as PI-RADS core criteria are subjective for radiologists. The application of artificial intelligence may support radiologists in interpreting MRI scans. This review addresses the quality of prostate multiparametric MRI (mpMRI) structured reporting (include improvements in acquisition using artificial intelligence) in terms of size of prostate gland, imaging quality, lesion location, lesion size, TNM staging, sector map, and discusses the future prospects of quality in MR reporting.

Multiparametric magnetic resonance imaging (mpMRI) is increasingly used for risk stratification and localization of prostate cancer (PCa). Thanks to the great success of deep learning models in computer vision, the potential application for early detection of PCa using mpMRI is imminent.Deep learning analysis of the PROSTATEx dataset.In this study, we show a simple convolutional neural network (CNN) with mpMRI can achieve high performance for detection of clinically significant PCa (csPCa), depending on the pulse sequences used. The mpMRI model with T2-ADC-DWI achieved 0.90 AUC score in the held-out test set, not significantly better than the model using KConvolutional neural networks incorporating multiple pulse sequences show high performance for detection of clinically-significant prostate cancer, and the model including dynamic contrast-enhanced information correlates best with grade.

Background While Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 lesions typically warrant prostate biopsy and PI-RADS 1 and 2 lesions may be safely observed, PI-RADS 3 lesions are equivocal. Purpose To construct and cross-validate a machine learning model based on radiomics features from T2 -weighted imaging (T2 WI) of PI-RADS 3 lesions to identify clinically significant prostate cancer (csPCa), that is, pathological Grade Group ≥ 2. Study type Single-center retrospective study. Population A total of 240 patients were included (training cohort, n = 188, age range 43-82 years; test cohort, n = 52, age range 41-79 years). Eligibility criteria were 1) magnetic resonance imaging (MRI)-targeted biopsy between 2015 and 2020; 2) PI-RADS 3 index lesion identified on multiparametric MRI; (3) biopsy performed within 1 year of MRI. The percentages of csPCa lesions were 10.6% and 15.4% in the training and test cohorts, respectively. Field strength/sequence A 3 T; T2 WI turbo-spin echo, diffusion-weighted spin-echo echo planar imaging, dynamic contrast-enhanced MRI with time-resolved T1-weighted imaging. Assessment Multislice volumes-of-interest (VOIs) were drawn in the PI-RADS 3 index lesions on T2 WI. A total of 107 radiomics features (first-order histogram and second-order texture) were extracted from the segmented lesions. Statistical tests A random forest classifier using the radiomics features as input was trained and validated for prediction of csPCa. The performance of the machine learning classifier, prostate specific antigen (PSA) density, and prostate volume for csPCa prediction was evaluated using receiver operating characteristic (ROC) analysis. Results The trained random forest classifier constructed from the T2 WI radiomics features good and statistically significant area-under-the-curves (AUCs) of 0.76 (P = 0.022) for prediction of csPCa in the test set. Prostate volume and PSA density showed moderate and nonsignificant performance (AUC 0.62, P = 0.275 and 0.61, P = 0.348, respectively) for csPCa prediction in the test set. Conclusion The machine learning classifier based on T2 WI radiomic features demonstrated good performance for prediction of csPCa in PI-RADS 3 lesions. Evidence level 4 TECHNICAL EFFICACY: 2.

Prostate heterogeneity on multi-parametric MRI (mpMRI) may confound image interpretation by obscuring lesions; systematic biopsy may have a role in this context.To determine if prostate heterogeneity (1) correlates with clinical risk factors for prostate cancer and (2) associates with higher-grade tumor in systematic biopsy (SB), compared with MRI-directed target biopsy (MDTB), i.e., SB MDTB, thus providing a rationale for combined biopsy.IRB-approved retrospective study included men who underwent mpMRI, SB, and MDTB between 2015 and 2017. Regions of interest were applied to the entire transition zone (TZ) and peripheral zone (PZ) on T2-weighted imaging (T2WI), apparent diffusion coefficient maps (ADC), and early dynamic contrast-enhanced (DCE) images on the midgland slice. Mean signal intensities and standard deviation (SD) of each zone were calculated. SD served as a measure of heterogeneity. Spearman's rank correlation analysis of clinical and imaging variables was performed. Univariate logistic regression was used to determine if any imaging variable associated with SB MDTB.93 patients were included. Significant correlations included age and TZ ADC heterogeneity (rho = 0.34, p = 0.013), PSA density, and mean TZ ADC (rho = - 0.29, p = 0.049). PZ T2WI heterogeneity correlated with PZ ADC heterogeneity (rho = 0.48, p 0.001). PZ DCE heterogeneity correlated with TZ DCE heterogeneity (rho = 0.46, p 0.001). TZ ADC heterogeneity was associated with SB MDTB prior to multiple comparison correction (p = 0.032). p value after correction was 0.24.TZ ADC heterogeneity correlated with age and may reflect prostatic hyperplasia and/or prostate cancer. PZ heterogeneity, possibly a measure of prostatitis, correlated with TZ hyperplasia and/or inflammation. TZ ADC heterogeneity was associated with SB MDTB with p value of 0.05 prior to multiple correction; future investigation is needed to further elucidate significance of ADC heterogeneity in prostate imaging.

To quantify Gleason score (GS) heterogeneity within multiparametric magnetic resonance imaging (MRI)-targeted prostate biopsies and to determine impact on National Comprehensive Cancer Network (NCCN) risk stratification. An Institutional Review Board-approved retrospective study was performed on men who underwent Artemis (MRI-transrectal–ultrasound fusion) targeted biopsy (TB) for suspected prostate cancer between 2012 and 2015. Intratarget heterogeneity was defined as a difference in GS between 2 cores within a single target in patients with ≥2 positive cores. Prostate specific antigen, maximum tumor diameter, apparent diffusion coefficient, MRI suspicion score, prostate volume, systematic biopsy (SB) GS, and T-stage were analyzed for correlation with heterogeneity. Changes in NCCN risk based on high versus low GS on TB, SB alone, and SB+TB were compared. Fifty-three patients underwent TB of 73 suspected lesions. Seventy percent (51/73) had ≥2 positive cores, thus meeting inclusion criteria for heterogeneity analysis. Fifty-five percent (28/51) of qualifying targets showed GS heterogeneity. None of the evaluated factors showed a significant relationship with heterogeneity. NCCN low-risk, intermediate-risk, and high-risk groups were 30%, 49%, and 21%, respectively, with SB alone. Adding low GS TB to SB resulted in 17%, 55%, 28% in each risk group, while using high GS+SB resulted in 4%, 54%, and 42%. Overall, the addition of TB resulted in higher NCCN risk groups in 38% of cases. Over half of multiparametric MRI-defined targets demonstrated GS heterogeneity. The addition of high GS from TB leads to risk inflation compared with using SB alone. Further research is needed on how to integrate these findings into current risk stratification models and clinical practice.

OBJECTIVE To assess the qualitative and quantitative changes on prostate multiparametric magnetic resonance imaging (mpMRI) following partial gland ablation (PGA) with cryotherapy and correlate with histopathology. METHODS We used 3D Slicer to generate prostate models and segment ipsilateral (treated) and contralateral peripheral and transition zones in 10 men who underwent MRI/transrectal ultrasound fusion-guided PGA during 2017-2018. Pre- and post-PGA volumes of prostate segments were compared. Post-PGA mpMRI were categorized according to PI-RADS v2 and treatment response on mpMRI was assessed in a manner similar to the radiology evaluation framework following liver lesion ablation. RESULTS Median volume of ipsilateral peripheral and transition zones decreased from 10.9 mL and 13.0 mL to 7.2 mL and 10.8 mL (P = .005), respectively. Median volume of contralateral peripheral and transition zones also decreased from 12.1 mL and 12.5 mL to 9.9 mL to 10.4 mL (P = .005), respectively. Five men had clinically significant disease (Grade group ≥2) on post-PGA biopsy (3 within treatment field and 2 outside). Of the men with clinically significant prostate cancer, mpMRI revealed PI-RADS 3 lesions in 2. However, the treatment response framework did not detect residual disease. CONCLUSION PGA results in asymmetrical and significant reductions in prostate volume. Our results highlight the need for a separate assessment framework to enable standardization of the interpretation and reporting of post-PGA surveillance mpMRI. Moreover, our findings have significant implications for MRI-targeted surveillance biopsy following PGA with cryotherapy.

ObjectiveAlthough the feasibility of transperineal biopsy under local anesthesia has been demonstrated, little is known regarding the application of MRI/ultrasound software fusion targeted biopsy for transperineal biopsy under local anesthesia. The objective of our study is to describe our initial experience with in-office transperineal MRI/ultrasound software fusion targeted biopsy (Idea, Development, Exploration, Assessment, Long-term Follow-up [IDEAL] Stage 2a).MethodsBetween October 2017 and July 2019, 33 men underwent in-office transperineal MRI-targeted biopsy using the Artemis (Eigen, Grass Valley, CA, USA) fixed-robotic arm system. The indication for biopsy was elevated prostate specific antigen (PSA) (n=14), prior negative biopsy (n=10), active surveillance (n=6), and surveillance after partial gland cryoablation (n=3). We prospectively captured patient demographic and clinical characteristics, biopsy outcomes, and complications. Complications were classified according to Common Terminology Criteria for Adverse Events (CTCAE) V.5.0.ResultsThe median patient age was 67 years (IQR 61–71) and the median serum PSA level was 7.0 ng/mL (IQR 5.1–11.4). The median duration of in-office MRI-targeted transperineal biopsy was 26 min (IQR 23–28). Overall, transperineal MRI-targeted biopsy detected prostate cancer in 18 (54.6%) men, with 8 (24.2%) being clinically significant (Gleason Score ≥3+4, Grade Group ≥2). Clinically significant prostate cancer was detected in four (28.6%) biopsy naïve men, two (20.0%) men with a prior negative, one (16.7%) man on active surveillance and one (33.3%) man following partial gland ablation. Three (9.1%) men experienced complications: two hematuria and one urinary retention.ConclusionOur findings demonstrate the feasibility of the fixed-robotic arm fusion platform for in-office transperineal MRI-targeted biopsy and a low rate of adverse events. However, larger prostate size precludes MRI/ultrasound software fusion and pubic arch interference hindered the transperineal MRI-targeted approach in 9.1% of men. Pubic arch interference was overcome by a free-hand approach with software fusion guidance.

Context Multiparametric magnetic resonance imaging (mpMRI)-targeted transrectal prostate biopsy (TBx) may better predict pathology at radical prostatectomy than systematic transrectal prostate biopsy (SBx). Objective To assess concordance between biopsy and radical prostatectomy pathology in men undergoing a TBx as compared with those undergoing an SBx. Evidence acquisition Four electronic databases (Ovid MEDLINE, Ovid EMBASE, the Cochrane Library [Wiley], and EBSCHOHost) were searched from inception until July 2018. Studies were included if they were published after 2012, conducted both SBx and TBx, and compared the biopsy results with final pathology after radical prostatectomy for ≥50 patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized. Bias was appraised using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Evidence synthesis Our search yielded 10 studies including 1215 men. However, our inclusion criteria applied only to a proportion of men included in these studies. The median age was 65 yr and the median prostate-specific antigen level was 7.2 ng/ml. In the eight studies examining upgrading at prostatectomy, pathology from SBx was significantly more likely to be upgraded relative to TBx (odds ratio [OR] 2.47, 95% confidence interval [CI] 1.48–4.14, p = 0.001). We found no significant difference in downgrading (OR 1.13, 95% CI 0.48–2.67, p = 0.783) between TBx and SBx. For both biopsy-naive men and men with a prior negative biopsy, results from SBx were more likely to be upgraded than TBx at prostatectomy (OR 1.6 [95% CI 1.02–2.27, p Conclusions Pathologic upgrading at prostatectomy was less likely with mpMRI-targeted biopsy versus systematic biopsy alone, without concurrent increase in downgrading. This increased accuracy should improve confidence in management decisions based on MRI-targeted biopsy pathology. Patient summary We reviewed the ability of multiparametric magnetic resonance imaging –targeted biopsy to predict cancer grade at radical prostatectomy. We found that targeted biopsy provides more accurate assessment of Gleason score at prostatectomy than systematic biopsy.

Purpose To develop and evaluate a rapid three-dimensional (3D) quantitative T2 mapping method for prostate cancer imaging using dual echo steady state (DESS) MRI at 3T. Methods In simulations, DESS-T2 mapping in the presence of T1 and B1+ variations was evaluated. In a phantom and in healthy volunteers (n = 4), 3D DESS-T2 mapping was compared with a two-dimensional turbo spin echo (TSE) approach. In volunteers and a pilot patient study (n = 29), quantitative T2 in normal prostate anatomical zones and in suspected cancerous lesions was evaluated. Results The simulated bias for DESS-T2 was

ObjectivesCryoablation for prostate cancer is typically performed under general anaesthesia. We explore the safety, feasibility and costs of in-office MRI-targeted prostate partial gland cryoablation (PGC) under local anaesthesia. We hypothesise that an office-based procedure under local anaesthesia may yield greater patient convenience and lower health costs with similar outcomes to a general anaesthesia approach.Design/participants/setting/interventionsRetrospective study of men diagnosed with clinically significant prostate cancer (grade group (GG) ≥2) who elected to undergo in-office PGC under local anaesthesia.Main outcome measuresA total of 55 men with GG ≥2 prostate cancer underwent PGC under local anaesthesia, and 35 of 43 men (81.4%) who attained ≥6 months of follow-up post-treatment underwent MRI-targeted surveillance biopsy. We used MRI findings and targeted biopsy to characterise post-PGC oncological outcomes. Complications were categorised using Common Terminology Criteria for Adverse Events (CTCAE). Expanded Prostate Cancer Index-Clinical Practice was used to characterise urinary and sexual function scores at baseline, 4 and 9 months post-PGC. Time-driven activity-based costing was used to determine healthcare costs of in-office PGC.ResultsFive (9.1%) men experienced CTCAE score 3 adverse events. Urinary and sexual function did not change significantly from baseline to 4 months (p=0.20 and p=0.08, respectively) and 9 months (p=0.23 and p=0.67, respectively). Twenty-two men (62.9%) had no cancer or GG1 and 13 (37.1%) men had GG≥2 on post-PGC biopsy. Moreover, the median cost of in-office PGC was US$4,463.05 (range US$4,087.19–US7,238.16) with disposables comprising 69% of the cost.ConclusionsIn-office PGC is feasible under local anaesthesia with favourable functional outcome preservation and adverse events profile at significantly lower costs compared with a general anaesthesia approach.

OBJECTIVES: We sought to identify clinical and MRI characteristics in men with PI-RADS category 3 index lesions that predict clinically significant prostate cancer (PCa) on MRI targeted biopsy. MATERIALS AND METHODS: Multi-center study of prospectively collected data for biopsy-naive men (n=247) who underwent MRI-targeted and systematic biopsies for PI-RADS 3 index lesions. The primary endpoint was diagnosis of clinically significant PCa (Grade Group ≥2). Multivariable logistic regression models assessed for factors associated with clinically significant PCa. The probability distributions of clinically significant PCa based on different levels of predictors of multivariable models were plotted in a heatmap. RESULTS: Men with clinically significant PCa had smaller prostate volume (39.20 vs 55.10 mL, p0.15 ng/ml2 (OR 3.51, 95%CI 1.61–7.68) were independently associated with significant PCa. CONCLUSION: Higher PSA density, lower prostate volume and ADC values are associated with clinically significant PCa in biopsy-naïve men with PI-RADS 3 lesions. We present regression-derived probabilities of detecting clinically significant PCa based on various clinical and imaging values that can be used in decision-making. Our findings demonstrate an opportunity for MRI refinement or biomarker discovery to improve risk stratification for PI-RADS 3 lesions.

PurposeFor men with an elevated prostate-specific antigen (PSA), there is a strong evidence for prostate MRI to assess the risk of clinically significant prostate cancer (CSPC) and guide targeted-biopsy interventions. Prostate MRI is assessed using the Prostate Imaging-Reporting and Data System (PI-RADS), which is scored from 1 to 5. Equivocal or suspicious findings (PI-RADS 3–5) are recommended for subsequent targeted biopsy, for which the risk of infection and sepsis is increasing. However, PI-RADS was developed primarily in men of European descent. We sought to elucidate PI-RADS and MRI-targeted biopsy outcomes in Asian men, a rapidly growing population in the USA, Europe, Australia and internationally.Materials and methodsA prospective cohort of 544 men with elevated PSA without a diagnosis of prostate cancer who underwent MRI-targeted biopsy at our institution from January 2012 to December 2018 was analyzed. We categorized the cohort by self-designated race then used a validated algorithm which uses surname lists to identify a total of 78 (14%) Asian-Americans. The primary outcome was the likelihood of diagnosing CSPC (Gleason grade group >1) in Asian-Americans versus non-Asian-Americans. Multivariable logistic regression was used to determine the association of demographic and other characteristics with CSPC.ResultsOverall, MRI-targeted biopsy identified CSPC in 17% of Asian-American men versus 39% of non-Asian-American men (pConclusionWe found that PI-RADS underperforms in Asian-American men. For instance, only 2 of 35 (6%) Asian-American men with PI-RADS 3 were diagnosed with CSPC on MRI targeted biopsy. This has significant implications for overuse of diagnostic and image-guided interventional approaches in Asian-Americans, given the increasing risk of infectious complications from biopsy. Additional validation studies are needed to confirm our findings.

© 2015 John Wiley & Sons, Ltd. The overlap of metabolites is a major limitation in one-dimensional (1D) spectral-based single-voxel MRS and multivoxel-based MRSI. By combining echo planar spectroscopic imaging (EPSI) with a two-dimensional (2D) J-resolved spectroscopic (JPRESS) sequence, 2D spectra can be recorded in multiple locations in a single slice of prostate using four-dimensional (4D) echo planar J-resolved spectroscopic imaging (EP-JRESI). The goal of the present work was to validate two different non-linear reconstruction methods independently using compressed sensing-based 4D EP-JRESI in prostate cancer (PCa): maximum entropy (MaxEnt) and total variation (TV). Twenty-two patients with PCa with a mean age of 63.8 years (range, 46-79 years) were investigated in this study. A 4D non-uniformly undersampled (NUS) EP-JRESI sequence was implemented on a Siemens 3-T MRI scanner. The NUS data were reconstructed using two non-linear reconstruction methods, namely MaxEnt and TV. Using both TV and MaxEnt reconstruction methods, the following observations were made in cancerous compared with non-cancerous locations: (i) higher mean (choline + creatine)/citrate metabolite ratios; (ii) increased levels of (choline + creatine)/spermine and (choline + creatine)/myo-inositol; and (iii) decreased levels of (choline + creatine)/(glutamine + glutamate). We have shown that it is possible to accelerate the 4D EP-JRESI sequence by four times and that the data can be reliably reconstructed using the TV and MaxEnt methods. The total acquisition duration was less than 13 min and we were able to detect and quantify several metabolites.

We have developed a system for evaluating magnetic resonance imaging of prostate cancer, using patient-specific 3D printed molds to facilitate MR-histology correlation. Prior to radical prostatectomy a patient receives a multiparametric MRI, which an expert genitourinary radiologist uses to identify and contour regions suspicious for disease. The same MR series is used to generate a prostate contour, which is the basis for design of a patient-specific mold. The 3D printed mold contains a series of evenly spaced parallel slits, each of which corresponds to a known MRI slice. After surgery, the patient’s specimen is enclosed within the mold, and all whole-mount levels are obtained simultaneously through use of a multi-bladed slicing device. The levels are then formalin fixed, processed, and delivered to an expert pathologist, who identifies and grades all lesions within the slides. Finally, the lesion contours are loaded into custom software, which elastically warps them to fit the MR prostate contour. The suspicious regions on MR can then be directly compared to lesions on histology. Furthermore, the false-negative and false-positive regions on MR can be retrospectively examined, with the ultimate goal of developing methods for improving the predictive accuracy of MRI. This work presents the details of our analysis method, following a patient from diagnosis through the MR-histology correlation process. For this patient MRI successfully predicted the presence of cancer, but true lesion volume and extent were underestimated. Most cancer-positive regions missed on MR were observed to have patterns of low T2 signal, suggesting that there is potential to improve sensitivity.

The application of compressed sensing is demonstrated in a recently implemented four-dimensional echo-planar based J-resolved spectroscopic imaging sequence combining two spatial and two spectral dimensions. The echo-planar readout simultaneously acquires one spectral and one spatial dimension. Therefore, the compressed sensing undersampling is performed along the indirectly acquired spatial and spectral dimensions, and the reconstruction is performed using the split Bregman algorithm, an efficient TV-minimization solver. The four-dimensional echo-planar-based J-resolved spectroscopic imaging data acquired in a prostate phantom containing metabolites at physiological concentrations are accurately reconstructed with as little as 20% of the original data. Experimental data acquired in six healthy prostates using the external body matrix "receive" coil on a 3T magnetic resonance imaging scanner are reconstructed with acquisitions using only 25% of the Nyquist-Shannon required amount of data, indicating the potential for a 4-fold acceleration factor in vivo, bringing the required scan time for multidimensional magnetic resonance spectroscopic imaging within clinical feasibility.