Automated prostate multi-regional segmentation in magnetic resonance using fully convolutional neural networks.

OBJECTIVE: Automatic MR imaging segmentation of the prostate provides relevant clinical benefits for prostate cancer evaluation such as calculation of automated PSA density and other critical imaging biomarkers. Further, automated T2-weighted image segmentation of central-transition zone (CZ-TZ), peripheral zone (PZ), and seminal vesicle (SV) can help to evaluate clinically significant cancer following the PI-RADS v2.1 guidelines. Therefore, the main objective of this work was to develop a robust and reproducible CNN-based automatic prostate multi-regional segmentation model using an intercontinental cohort of prostate MRI. METHODS: A heterogeneous database of 243 T2-weighted prostate studies from 7 countries and 10 machines of 3 different vendors, with the CZ-TZ, PZ, and SV regions manually delineated by two experienced radiologists (ground truth), was used to train (n = 123) and test (n = 120) a U-Net-based model with deep supervision using a cyclical learning rate. The performance of the model was evaluated by means of dice similarity coefficient (DSC), among others. Segmentation results with a DSC above 0.7 were considered accurate. RESULTS: The proposed method obtained a DSC of 0.88 ± 0.01, 0.85 ± 0.02, 0.72 ± 0.02, and 0.72 ± 0.02 for the prostate gland, CZ-TZ, PZ, and SV respectively in the 120 studies of the test set when comparing the predicted segmentations with the ground truth. No statistically significant differences were found in the results obtained between manufacturers or continents. CONCLUSION: Prostate multi-regional T2-weighted MR images automatic segmentation can be accurately achieved by U-Net like CNN, generalizable in a highly variable clinical environment with different equipment, acquisition configurations, and population. KEY POINTS: • Deep learning techniques allows the accurate segmentation of the prostate in three different regions on MR T2w images. • Multi-centric database proved the generalization of the CNN model on different institutions across different continents. • CNN models can be used to aid on the diagnosis and follow-up of patients with prostate cancer.

Multicenter Repeatability and Reproducibility of MR Fingerprinting in Phantoms and in Prostatic Tissue.

PURPOSE: To evaluate multicenter repeatability and reproducibility of T1 and T2 maps generated using MR fingerprinting (MRF) in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom and in prostatic tissues. METHODS: MRF experiments were performed on 5 different 3 Tesla MRI scanners at 3 different institutions: University Hospitals Cleveland Medical Center (Cleveland, OH), Brigham and Women's Hospital (Boston, MA) in the United States, and Diagnosticos da America (Rio de Janeiro, RJ) in Brazil. Raw MRF data were reconstructed using a Gadgetron-based MRF online reconstruction pipeline to yield quantitative T1 and T2 maps. The repeatability of T1 and T2 values over 6 measurements in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom was assessed to demonstrate intrascanner variation. The reproducibility between the 4 clinical scanners was assessed to demonstrate interscanner variation. The same-day test-retest normal prostate mean T1 and T2 values from peripheral zone and transitional zone were also compared using the intraclass correlation coefficient and Bland-Altman analysis. RESULTS: The intrascanner variation of values measured using MRF was less than 2% for T1 and 4.7% for T2 for relaxation values, within the range of 307.7 to 2360 ms for T1 and 19.1 to 248.5 ms for T2 . Interscanner measurements showed that the T1 variation was less than 4.9%, and T2 variation was less than 8.1% between multicenter scanners. Both T1 and T2 values in in vivo prostatic tissue demonstrated high test-retest reliability (intraclass correlation coefficient > 0.92) and strong linear correlation (R2  > 0.840). CONCLUSION: Prostate MRF measurements of T1 and T2 are repeatable and reproducible between MRI scanners at different centers on different continents for the above measurement ranges.

Risk-based MRI-directed diagnostic pathway outperforms non-risk-based pathways in suspected prostate cancer biopsy-naïve men: a large cohort validation study.

OBJECTIVES: To investigate and compare the performance of different proposed diagnostic pathways in a cohort of biopsy-naïve men at risk for prostate cancer (PCa), in terms of biopsy avoidance, accurate diagnosis of clinically significant prostate cancer (csPCa), and reduction in overdiagnosis of clinically insignificant cancer (cisPCa), with particular focus on a recently suggested "risk-based" MRI-directed diagnostic pathway. METHODS: Single-center, retrospective cohort study, including 499 biopsy-naïve men at risk for PCa. All men underwent PI-RADS-compliant prostate MRI, transrectal ultrasound fusion-guided targeted (TBx), and systematic biopsy (SBx). Five diagnostic pathways were retrospectively evaluated and compared for. Outcome measures were biopsy avoidance, combined with missed csPCa and detected cisPCa. csPCa and cisPCa were defined as ISUP grade group ≥ 2 and grade = 1, respectively. Chi-square test was used for statistical analysis. Decision curve analyses were used to compare the benefits of the pathways across a range of biopsy thresholds. RESULTS: The prevalence (detection-focused [reference] pathway) of csPCa and cisPCa was 52.9% (264/499) and 23.0% (115/499). MRI-focused pathway (no biopsy in PI-RADS 1-2 men) did not significantly reduce ISUP ≥ 2 cancer detection (52.1% (260/499); p = 0.13), but significantly reduced ISUP 1 cancers diagnosed (20.6% (103/499); p < 0.01), and biopsy avoidance was 11.8% (59/499). The risk-based MRI-directed pathway (no biopsy in low-risk PI-RADS 1-3 men) resulted in a small reduction of ISUP ≥ 2 diagnosed (51.7% (258/499); p = 0.04), however non-significant when compared to MRI-focused pathway (p = 0.625). Moreover, the risk-based pathway further reduced detection of ISUP 1 (18.6% (93/499); p < 0.01), and biopsy avoidance was 19.2% (96/499). Decision curve analysis showed maximized net benefit of the risk-based pathway, for the range of threshold probabilities between 6.25 and 65%. CONCLUSION: The risk-based MRI-directed pathway for prostate cancer diagnosis was optimal in balancing accurate diagnosis, reducing overdiagnosis, and maximizing biopsy avoidance. This substantial evidence should inform guideline recommendations towards using "risk-based" MRI-directed biopsy decisions in biopsy-naïve men at risk of significant prostate cancer. KEY POINTS: • Our study recognizes the added value of prostate MRI and MR-targeted biopsies in order to propose clinical diagnostic pathways for prostate cancer, towards maximizing the potential avoidance of unnecessary biopsies, while maintaining optimal detection rate of clinically significant prostate cancer. • The risk-based MRI-directed pathway incorporates risk factors such as PSA density, digital rectal examination, and family history to further refine the initial stratification of patients based on PI-RADS scores. • In this study, the risk-based pathway had the most optimal performance in terms of combination of outcomes, with the highest rate of biopsy avoidance (19.2%), while keeping a high detection rate of clinically significant prostate cancer (51.7%), when compared to the reference standard (52.9%).

The role of cine MR imaging in the assessment of uterine function.

PURPOSE: To review the literature on uterine contraction and to highlight magnetic resonance imaging using the cine technique as a useful method to evaluate these movements. METHODS: The literature research on PubMed database was done up to February 2019 with restriction to English language about articles regarding uterine peristalsis and cine MR. RESULTS: Infertility is a common clinical problem and a source of frustration for those who want to have children. Uterine movements are crucial elements in respect of successful conception, implantation, and the development of a healthy pregnancy. It is known that the direction and frequency of uterine peristalsis are closely related to the different phases of the menstrual cycle, and that changes in its activity may interfere with reproduction. One condition that has been linked with infertility by several studies is dysfunctional uterine contractility. Magnetic resonance imaging, using the cine technique, has been shown to be a useful tool in the evaluation of these movements, allowing the identification of patients with some type of dysfunction and establish strategies to increase pregnancy rates. CONCLUSION: Cine MR is an excellent imaging method for the evaluation of uterine peristalsis and identification of dysfunctional contractions.

Computer-aided diagnosis prior to conventional interpretation of prostate mpMRI: an international multi-reader study.

OBJECTIVES: To evaluate if computer-aided diagnosis (CAD) prior to prostate multi-parametric MRI (mpMRI) can improve sensitivity and agreement between radiologists. METHODS: Nine radiologists (three each high, intermediate, low experience) from eight institutions participated. A total of 163 patients with 3-T mpMRI from 4/2012 to 6/2015 were included: 110 cancer patients with prostatectomy after mpMRI, 53 patients with no lesions on mpMRI and negative TRUS-guided biopsy. Readers were blinded to all outcomes and detected lesions per PI-RADSv2 on mpMRI. After 5 weeks, readers re-evaluated patients using CAD to detect lesions. Prostatectomy specimens registered to MRI were ground truth with index lesions defined on pathology. Sensitivity, specificity and agreement were calculated per patient, lesion level and zone-peripheral (PZ) and transition (TZ). RESULTS: Index lesion sensitivity was 78.2% for mpMRI alone and 86.3% for CAD-assisted mpMRI (p = 0.013). Sensitivity was comparable for TZ lesions (78.7% vs 78.1%; p = 0.929); CAD improved PZ lesion sensitivity (84% vs 94%; p = 0.003). Improved sensitivity came from lesions scored PI-RADS < 3 as index lesion sensitivity was comparable at PI-RADS ≥ 3 (77.6% vs 78.1%; p = 0.859). Per patient specificity was 57.1% for CAD and 70.4% for mpMRI (p = 0.003). CAD improved agreement between all readers (56.9% vs 71.8%; p < 0.001). CONCLUSIONS: CAD-assisted mpMRI improved sensitivity and agreement, but decreased specificity, between radiologists of varying experience. KEY POINTS: • Computer-aided diagnosis (CAD) assists clinicians in detecting prostate cancer on MRI. • CAD assistance improves agreement between radiologists in detecting prostate cancer lesions. • However, this CAD system induces more false positives, particularly for less-experienced clinicians and in the transition zone. • CAD assists radiologists in detecting cancer missed on MRI, suggesting a path for improved diagnostic confidence.

Porto-sinusoidal Vascular Disease and Portal Hypertension.

Porto-sinusoidal vascular disease (PSVD) is the medical diagnosis for a patient who has portal hypertension in the absence of cirrhosis on liver biopsy. There are several specific histologic findings for PSVD, including obliterative portal venopathy, nodular regenerative hyperplasia, and incomplete septal fibrosis. Epidemiologic reports vary widely among regions; PSVD comprises less than 10% of causes of portal hypertension in Western countries but incidence has been found to be as high as 48% in India. There is an expansive list of etiologies that have been reported to cause PSVD.

Emerging and anticipated innovations in prostate cancer MRI and their impact on patient care.

Prostate cancer (PCa) remains the leading malignancy affecting men, with over 3 million men living with the disease in the US, and an estimated 288,000 new cases and almost 35,000 deaths in 2023 in the United States alone. Over the last few decades, imaging has been a cornerstone in PCa care, with a crucial role in the detection, staging, and assessment of PCa recurrence or by guiding diagnostic or therapeutic interventions. To improve diagnostic accuracy and outcomes in PCa care, remarkable advancements have been made to different imaging modalities in recent years. This paper focuses on reviewing the main innovations in the field of PCa magnetic resonance imaging, including MRI protocols, MRI-guided procedural interventions, artificial intelligence algorithms and positron emission tomography, which may impact PCa care in the future.

Artificial intelligence applications in prostate cancer.

Artificial intelligence (AI) applications have enabled remarkable advancements in healthcare delivery. These AI tools are often aimed to improve accuracy and efficiency of histopathology assessment and diagnostic imaging interpretation, risk stratification (i.e., prognostication), and prediction of therapeutic benefit for personalized treatment recommendations. To date, multiple AI algorithms have been explored for prostate cancer to address automation of clinical workflow, integration of data from multiple domains in the decision-making process, and the generation of diagnostic, prognostic, and predictive biomarkers. While many studies remain within the pre-clinical space or lack validation, the last few years have witnessed the emergence of robust AI-based biomarkers validated on thousands of patients, and the prospective deployment of clinically-integrated workflows for automated radiation therapy design. To advance the field forward, multi-institutional and multi-disciplinary collaborations are needed in order to prospectively implement interoperable and accountable AI technology routinely in clinic.

PI-RADS 3 lesions: a critical review and discussion of how to improve management.

Since the publication of PI-RADS v1 in 2012, the debate regarding the question of how to manage PI-RADS 3 lesions has been mostly unsolved. However, based on our review of the current literature we discuss possible solutions and improvements to the original classification, factors such as PSAD (Prostate Specific Antigen Density), age, and tumor volume, in the decision of whether to proceed with a biopsy or not.

Deep infiltrating endometriosis: cine magnetic resonance imaging in the evaluation of uterine contractility.

Objective: To evaluate uterine function by using cine magnetic resonance imaging to visualize the contractile movements of the uterus in patients with and without deep infiltrating endometriosis (with or without associated adenomyosis). Materials and Methods: This was a prospective case-control study. The study sample comprised 43 women: 18 in the case group and 25 in the control group. We performed cine magnetic resonance imaging in a 3.0 T scanner, focusing on the presence, direction, and frequency of uterine peristalsis. Results: The frequency of uterine peristalsis was higher in the case group than in the control group, in the periovulatory phase (3.83 vs. 2.44 peristaltic waves in two minutes) and luteal phase (1.20 vs. 0.91 peristaltic waves in two minutes). However, those differences were not statistically significant. There was a significant difference between the patients with adenomyosis and those without in terms of the frequency of peristalsis during the late follicular/periovulatory phase (0.8 vs. 3.18 peristaltic waves in two minutes; p < 0.05). Conclusion: The frequency of uterine peristalsis appears to be higher during the periovulatory and luteal phases in patients with deep infiltrating endometriosis, whereas it appears to be significantly lower during the late follicular/periovulatory phase in patients with adenomyosis. Both of those effects could have a negative impact on sperm transport and on the early stages of fertilization.

Objetivo: Avaliar a função uterina mediante visualização dos movimentos contráteis do útero por meio de cine-ressonância magnética em pacientes com e sem endometriose infiltrativa profunda (com ou sem adenomiose associada). Materiais e Métodos: Estudo caso-controle prospectivo. A amostra foi composta por 43 mulheres, sendo 18 mulheres no grupo caso e 25 mulheres no grupo controle. A cine-ressonância magnética foi realizada com magneto 3.0 T, com foco na presença, direção e frequência do peristaltismo uterino. Resultados: O peristaltismo uterino foi mais frequente nas pacientes do grupo endometriose do que no grupo controle na fase periovulatória (3,83 × 2,44 peristalses em dois minutos) e lútea (1,20 × 0,91 peristalse em dois minutos). No entanto, esses resultados não foram estatisticamente significantes. Nas pacientes com adenomiose, observou-se redução significativa na frequência de peristaltismo durante a primeira fase do ciclo menstrual (3,18 × 0,8 peristalses; p < 0,05). Conclusão: A frequência de peristaltismo uterino parece estar aumentada durante a fase periovulatória e lútea em pacientes com endometriose infiltrativa profunda e significativamente reduzida em pacientes com adenomiose durante a primeira fase do ciclo menstrual. Ambos os efeitos têm potencial de interferir negativamente no transporte de espermatozoides e nos primeiros estágios de fecundação.

Magnetic resonance fingerprinting based comprehensive quantification of T1 and T2 values of the background prostatic peripheral zone: Correlation with clinical and demographic features.

PURPOSE: To quantify and assess the distribution of MR fingerprinting (MRF)-derived T1 and T2 values of the whole prostatic peripheral zone (PZ), and perform subgroup analyses according to clinical and demographic features. METHOD: One hundred and twenty-four patients with prostate MR exams and MRF-based T1 and T2 maps of the prostatic apex, mid gland, and base were identified from our database and included. Regions of interest encompassing the right and left lobes of the PZ were drawn for each axial slice on the T2 map and copied to the T1 map. Clinical data were obtained from medical records. Kruskal-Wallis test was used for assessing differences between subgroups and the Spearman coefficient was used for assessing any correlations. RESULTS: Mean T1 and T2 values were 1941 and 88 ms, respectively, for the whole-gland, 1884 and 83 ms for the apex, 1974 and 92 ms for the mid-gland, 1966 and 88 ms for the base. T1 values were weakly negatively correlated with PSA values, while T1 and T2 values were weakly positively correlated with prostate weight and moderately positively correlated with PZ width. Finally, patients with PI-RADS 1 scores had higher T1 and T2 values of the whole PZ, compared with those with scores 2-5. CONCLUSION: Mean T1 and T2 values of the background PZ of the whole gland were 1941 ± 313 and 88 ± 39 ms, respectively. Among clinical and demographic factors, there was a significant positive correlation between T1 and T2 values and PZ width.

Imaging in urethral stricture disease: an educational review of current techniques with a focus on MRI.

Urethral stricture disease refers to narrowing of the urethral lumen obstructing the flow of urine. Urethral strictures can significantly impact daily life due to incontinence, incomplete emptying, hesitancy, and increased risk of urinary tract infections. Imaging is central to the evaluation of suspected urethral stricture, as assessment of stricture length and severity is crucial for guidance of surgical management. The currently employed modalities include radiography, chiefly retrograde urethrography (RUG) and voiding cystourethrography (VCUG); magnetic resonance urethrography (MRU); and sonourethrography (SUG). MRU has become a recent focus of research as it provides high spatial resolution, multiplanar capacity, and soft tissue type differentiation for evaluation of periurethral compartments and concurrent soft tissue defects. The protocol for MRU has evolved over the years to now include dynamic micturition imaging and image reconstruction options. In this review, we discuss each of the imaging modalities used in the diagnosis and evaluation of urethral stricture and provide an overview of literature on MRU over the last decade, including suggested indications that have not yet been incorporated into current guidelines. We delineate scenarios where special diagnostic imaging beyond radiography is beneficial, providing examples from our practice and description of our techniques for each modality.

Spatiotemporal knowledge teacher-student reinforcement learning to detect liver tumors without contrast agents.

Detecting Liver tumors without contrast agents (CAs) has shown great potential to advance liver cancer screening. It enables the provision of a reliable liver tumor-detecting result from non-enhanced MR images comparable to the radiologists' results from CA-enhanced MR images, thus eliminating the high risk of CAs, preventing an experience gap between radiologists and simplifying clinical workflows. In this paper, we proposed a novel spatiotemporal knowledge teacher-student reinforcement learning (SKT-RL) as a safe, speedy, and inexpensive contrast-free technology for liver tumor detection. Our SKT-RL builds a teacher-student framework to realize the exploring of explicit liver tumor knowledge from a teacher network on clear contrast-enhanced images to guide a student network to detect tumors from non-enhanced images directly. Importantly, our STK-RL enables three novelties in aspects of construction, transferring, and optimization to tumor knowledge to improve the guide effect. (1) A new spatiotemporal ternary knowledge set enables the construction of accurate knowledge that allows understanding of DRL's behavior (what to do) and reason (why to do it) behind reliable detection within each state and between their related historical states. (2) A novel pixel momentum transferring strategy enables detailed and controlled knowledge transfer ability. It transfers knowledge at a pixel level to enlarge the explorable space of transferring and control how much knowledge is transferred to prevent over-rely of the student to the teacher. (3) A phase-trend reward function designs different evaluations according to different detection phases to optimal for each phase in high-precision but also allows reward trend to constraint the evaluation to improve stability. Comprehensive experiments on a generalized liver tumor dataset with 375 patients (including hemangiomas, hepatocellular carcinoma, and normal controls) show that our novel SKT-RL attains a new state-of-the-art performance (improved precision by at least 4% when comparing the six recent advanced methods) in the task of liver tumor detection without CAs. The results proved that our SKT-DRL has greatly promoted the development and deployment of contrast-free liver tumor technology.

Evaluating the Downstream Revenues of a Self-Pay Bi-Parametric Prostate MRI Program.

OBJECTIVE: To quantify downstream healthcare utilization and revenue associated with a self-pay bi-parametric prostate MRI (bpMRI) program. METHODS: Medical records of 592 patients who underwent bpMRI between August 2017 and March 2020 were examined for follow-up clinical activities. These include prostate biopsy, radical prostatectomy, external beam radiation therapy, brachytherapy, androgen deprivation therapy, CT Chest, Abdomen and Pelvis, PET/CT, MRI Pelvis, and Nuclear Medicine Bone Scans. The charges for each clinical activity were derived from the Medicare Physician Fee Schedule to conservatively estimate revenues. This patient population was further divided into four groups: Group A, patients who demonstrated an MRI lesion and underwent prostatectomy; Group B, patients who did not demonstrate lesion but underwent prostatectomy; Group C, patients who demonstrated lesion but did not undergo prostatectomy; and Group D, patients who neither demonstrated lesion nor underwent prostatectomy. Revenues for each group were categorized by Urology, Radiation Oncology and Radiology subspecialties. RESULTS: Conservative estimates yielded $520 of downstream revenue per patient who underwent bpMRI. Group A patients yielded 47% of total revenue ($1974 per patient). Group B patients, the smallest group, yielded $1828 per patient. Group C patients made up the largest group and grossed $398 per patient. Group D demonstrated the lowest per patient revenue of $179. Groups A and B yielded most relative revenue for Urology. Group C yielded most relative revenue for Radiation Oncology, and Group D yielded most relative revenue for Radiology. CONCLUSION: A self-pay bpMRI program has the potential to improve patient access to prostate cancer screening while remaining financial sustainable.

Novel radiomic analysis on bi-parametric MRI for characterizing differences between MR non-visible and visible clinically significant prostate cancer.

Background: around one third of clinically significant prostate cancer (CsPCa) foci are reported to be MRI non-visible (MRI─). Objective: To quantify the differences between MR visible (MRI+) and MRI─ CsPCa using intra- and peri-lesional radiomic features on bi-parametric MRI (bpMRI). Methods: This retrospective and multi-institutional study comprised 164 patients with pre-biopsy 3T prostate multi-parametric MRI from 2014 to 2017. The MRI─ CsPCa referred to lesions with PI-RADS v2 score < 3 but ISUP grade group > 1. Three experienced radiologists were involved in annotating lesions and PI-RADS assignment. The validation set (Dv) comprised 52 patients from a single institution, the remaining 112 patients were used for training (Dt). 200 radiomic features were extracted from intra-lesional and peri-lesional regions on bpMRI.Logistic regression with least absolute shrinkage and selection operator (LASSO) and 10-fold cross-validation was applied on Dt to identify radiomic features associated with MRI─ and MRI+ CsPCa to generate corresponding risk scores RMRI─ and RMRI+. RbpMRI was further generated by integrating RMRI─ and RMRI+. Statistical significance was determined using the Wilcoxon signed-rank test. Results: Both intra-lesional and peri-lesional bpMRI Haralick and CoLlAGe radiomic features were significantly associated with MRI─ CsPCa (p < 0.05). Intra-lesional ADC Haralick and CoLlAGe radiomic features were significantly different among MRI─ and MRI+ CsPCa (p < 0.05). RbpMRI yielded the highest AUC of 0.82 (95 % CI 0.72-0.91) compared to AUCs of RMRI+ 0.76 (95 % CI 0.63-0.89), and PI-RADS 0.58 (95 % CI 0.50-0.72) on Dv. RbpMRI correctly reclassified 10 out of 14 MRI─ CsPCa on Dv. Conclusion: Our preliminary results demonstrated that both intra-lesional and peri-lesional bpMRI radiomic features were significantly associated with MRI─ CsPCa. These features could assist in CsPCa identification on bpMRI.

Impact of Magnetic Resonance Imaging Targeting on Pathologic Upgrading and Downgrading at Prostatectomy: A Systematic Review and Meta-analysis.

CONTEXT: The evidence supporting multiparametric magnetic resonance imaging (MRI) targeting for biopsy is nearly exclusively based on biopsy pathologic outcomes. This is problematic, as targeting likely allows preferential identification of small high-grade areas of questionable oncologic significance, raising the likelihood of overdiagnosis and overtreatment. OBJECTIVE: To estimate the impact of MRI-targeted, systematic, and combined biopsies on radical prostatectomy (RP) grade group concordance. EVIDENCE ACQUISITION: PubMed MEDLINE and Cochrane Library were searched from July 2018 to January 2022. Studies that conducted systematic and MRI-targeted prostate biopsies and compared biopsy results with pathology after RP were included. We performed a meta-analysis to assess whether pathologic upgrading and downgrading were influenced by biopsy type and a net-benefit analysis using pooled risk difference estimates. EVIDENCE SYNTHESIS: Both targeted only and combined biopsies were less likely to result in upgrading (odds ratio [OR] vs systematic of 0.70, 95% confidence interval [CI] 0.63-0.77, p < 0.001, and 0.50, 95% CI 0.45-0.55, p < 0.001), respectively). Targeted only and combined biopsies increased the odds of downgrading (1.24 (95% CI 1.05-1.46), p = 0.012, and 1.96 (95% CI 1.68-2.27, p < 0.001) compared with systematic biopsies, respectively. The net benefit of targeted and combined biopsies is 8 and 7 per 100 if harms of up- and downgrading are considered equal, but 7 and -1 per 100 if the harm of downgrading is considered twice that of upgrading. CONCLUSIONS: The addition of MRI-targeting results in lower rates of upgrading as compared to systematic biopsy at RP (27% vs 42%). However, combined MRI-targeted and systematic biopsies are associated with more downgrading at RP (19% v 11% for combined vs systematic). Strong heterogeneity suggests further research into factors that influence the rates of up- and downgrading and that distinguishes clinically relevant from irrelevant grade changes is needed. Until then, the benefits and harms of combined MRI-targeted and systematic biopsies cannot be fully assessed. PATIENT SUMMARY: We reviewed the ability of magnetic resonance imaging (MRI)-targeted biopsies to predict cancer grade at prostatectomy. We found that combined MRI-targeted and systematic biopsies result in more cancers being downgraded than systematic biopsies.

Prostate MRI: diffusion-weighted imaging at 1.5T correlates better with prostatectomy Gleason Grades than TRUS-guided biopsies in peripheral zone tumours.

OBJECTIVES: To investigate the usefulness of Apparent Diffusion Coefficients (ADC) in predicting prostatectomy Gleason Grades (pGG) and Scores (GS), compared with ultrasound-guided biopsy Gleason Grades (bGG). METHODS: Twenty-four patients with biopsy-proven prostate cancer were included in the study. Diffusion-weighted images were obtained using 1.5-T MR with a pelvic phased-array coil. Median ADC values (b0,500,1000 s/mm²) were measured at the most suspicious areas in the peripheral zone. The relationship between ADC values and pGG or GS was assessed using Pearson's coefficient. The relationship between bGG and pGG or GS was also evaluated. Receiver operating characteristic (ROC) curve analysis was performed to assess the performance of each method on a qualitative level. RESULTS: A significant negative correlation was found between mean ADCs of suspicious lesions and their pGG (r = -0.55; p < 0.01) and GS (r = -0.63; p < 0.01). No significant correlation was found between bGG and pGG (r = 0.042; p > 0.05) or GS (r = 0.048; p > 0.05). ROC analysis revealed a discriminatory performance of AUC = 0.82 for ADC and AUC = 0.46 for bGG in discerning low-grade from intermediate/high-grade lesions. CONCLUSIONS: The ADC values of suspicious areas in the peripheral zone perform better than bGG in the correlation with prostate cancer aggressiveness, although with considerable intra-subject heterogeneity. KEY POINTS: • Prostate cancer aggressiveness is probably underestimated and undersampled by routine ultrasound-guided biopsies. • Diffusion-weighted MR images show good linear correlation with prostate cancer aggressiveness. • DWI information may be used to improve risk-assessment in prostate cancer.

MR imaging in deep pelvic endometriosis: a pictorial essay.

Deep pelvic endometriosis is an important gynecologic disorder that is responsible for severe pelvic pain and is defined as subperitoneal invasion that exceeds 5 mm in depth. Deep pelvic endometriosis can affect the retrocervical region, uterosacral ligaments, rectum, rectovaginal septum, vagina, urinary tract, and other extraperitoneal pelvic sites. It is commonly associated with dysmenorrhea, dyspareunia, pelvic pain, urinary tract symptoms, and infertility. Because surgery remains the best therapeutic option for affected patients, the accurate preoperative assessment of the extension of endometriotic disease is extremely important. Pelvic magnetic resonance (MR) imaging is a noninvasive method with high spatial resolution that allows multiplanar evaluation of deep pelvic endometriosis and good tissue characterization, but without the use of ionizing radiation or iodinated contrast agents. MR imaging yields important findings that help grade the disease and identify subperitoneal lesion extension and other associated disease entities, thereby facilitating accurate diagnosis and adequate treatment. Radiologists should be familiar with the MR imaging findings of deep infiltrating endometriosis in various anatomic locations so that they can provide information that allows adequate presurgical counseling.

Seamless Integration of Artificial Intelligence Into the Clinical Environment: Our Experience With a Novel Pneumothorax Detection Artificial Intelligence Algorithm.

Although interest in artificial intelligence (AI) has exploded in recent years and led to the development of numerous commercial and noncommercial algorithms, the process of implementing such tools into day-to-day clinical practice is rarely described in the burgeoning AI literature. In this report, we describe our experience with the successful integration of an AI-enabled mobile x-ray scanner with an FDA-approved algorithm for detecting pneumothoraces into an end-to-end solution capable of extracting, delivering, and prioritizing positive studies within our thoracic radiology clinical workflow. We also detail several sample cases from our AI algorithm and associated PACS workflow in action to highlight key insights from our experience. We hope this report can help inform other radiology enterprises seeking to evaluate and implement AI-related workflow solutions into daily clinical practice.

Practical recommendations for the safe use of gadolinium in magnetic resonance imaging: a Delphi expert panel study.

OBJECTIVE: To assess the practical aspects of the use of various gadolinium-based contrast agents (GBCAs) by radiologists. MATERIALS AND METHODS: Ten experienced radiologists from different regions of Brazil participated in a Delphi panel querying their use of various GBCAs, including linear and macrocyclic classes (1.0 and 0.5 M), in terms of the choice of agent, volume and dosage of the agents, and associated safety concerns. RESULTS: The response rate was 100% for all questions. GBCAs are safe in terms of acute adverse reactions, and nephrogenic systemic fibrosis is rare. The deposition of gadolinium in the brain and other tissues is a concern among the experts. Macrocyclic agents are preferable to linear agents; an injection volume below 0.1 mL/kg of a 1.0 M agent could result in good-quality images with additional long-term safety, but there is no published evidence to support this recommendation. The majority of experts preferred not to administer GBCAs to pregnant patients. CONCLUSION: When choosing a GBCA, it is important to consider the characteristics of the gadolinium deposition in patient tissues and minimize potential risks. Furthermore, medical education programs are needed to increase the awareness of the potential risks of gadolinium deposition and thus avoid instances of overexposure to the contrast agent.

OBJETIVO: Avaliar aspectos práticos do uso de agentes de contraste à base de gadolínio (gadolinium-based contrast agents - GBCAs) por médicos especialistas em radiologia. MATERIAIS E MÉTODOS: Dez radiologistas de diferentes regiões do Brasil foram convidados a participar de um painel Delphi com perguntas sobre o uso de GBCAs lineares e macrocíclicos (1,0 e 0,5 M), em termos de dosagem, volume injetado e preocupações relacionadas à segurança. RESULTADOS: A taxa de resposta foi de 100% para todas as perguntas. GBCAs são seguros em relação a reações adversas agudas, e os casos de fibrose nefrogênica sistêmica são raros. O depósito de gadolínio no cérebro e em outros tecidos é uma preocupação de todo o painel. Agentes macrocíclicos são preferíveis aos lineares. Um volume menor que 0,1 mL/kg injetado de contraste macrocíclico 1,0 M poderia oferecer imagem com boa qualidade e benefício adicional em longo prazo, entretanto, não há evidências publicadas que apóiem tal recomendação. A maioria prefere não administrar GBCA em gestantes. CONCLUSÃO: É importante considerar as características de deposição e minimizar potenciais riscos ao se escolher um GBCA. Ações de educação médica são necessárias para a conscientização dos potenciais riscos da presença de gadolínio em longo prazo e evitar a sobre-exposição ao agente de contraste.