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The detection of clinically significant prostate cancers while simultaneously avoiding over-diagnosing tumors with low malignant potential is a challenge in clinical practice.Multiparametric prostate magnetic resonance imaging (MRI) in accordance with the Prostate Imaging Reporting and Data System (PI-RADS) guidelines is accepted as standard-of-care with both urologists and radiologists.The PI-RADS guidelines have been updated to version 2.1, including revised technical recommendations and changes to the scoring of lesions.The PI-RADS guidelines have had great impact on the standardization of multiparametric prostate MRI and offer templates for structured reporting. This simplifies communication with the referring physician.The new version 2.1 of the guidelines represents an evolutionary improvement of the widely accepted version 2.0. Several aspects of reporting have been revised-however, some pre-known limitations persist, which will require further refinement in the future.KLINISCHES/METHODISCHES PROBLEM: Die Identifikation klinisch signifikanter Prostatakarzinome bei gleichzeitigem Vermeiden einer Überdiagnostik niedrigmaligner Tumoren stellt eine Herausforderung in der klinischen Routine dar.Die gemäß PI-RADS-Richtlinien (Prostate Imaging Reporting and Data System Guidelines) akquirierte und interpretierte multiparametrische Magnetresonanztomographie (MRT) der Prostata ist als klinischer Standard bei Urologen und Radiologen akzeptiert.Die PI-RADS-Richtlinien sind neu auf Version 2.1 aktualisiert worden und beinhalten neben präzisierten technischen Anforderungen einzelne Änderungen in der Läsionsbewertung. LEISTUNGSFäHIGKEIT: Die PI-RADS-Richtlinien haben entscheidende Bedeutung in der Standardisierung der multiparametrischen MRT der Prostata erlangt und bieten Vorlagen zur strukturierten Befundung, was die Kommunikation mit dem Zuweiser erleichtert.Die nun auf Version 2.1 aktualisierten Richtlinien stellen eine Verfeinerung der verbreiteten Version 2.0 dar. Dabei wurden viele Aspekte der Befundung präzisiert, einige vorbekannte Limitationen bleiben jedoch bestehen und erfordern die weitere Verbesserung der Richtlinien in kommenden Versionen.

Purpose: This study aimed to assess the feasibility of a rapid diffusion tensor imaging (DTI) for evaluation of the female urinary sphincter function based on differentiation between rest and muscle contraction.Methods: Magnetic resonance imaging (MRI) of the lower pelvis was performed at 3 Tesla in 10 healthy female volunteers (21–36 years; body mass index, 20.8±3.6 kg/m2) between June and July 2019. High-resolution T1- and T2-weighted images were acquired for anatomical reference, and following DTI performed in 4 experiment phases: twice during rest (denoted rest-1, rest-2) and contraction (contraction-1, contraction-2). Manual segmentation of the urinary sphincter and the levator ani muscles were performed by 2 independent readers. Mean diffusivity (MD) and fractional anisotropy (FA) values derived from DTI volumes were compared in search for significant differences between the experiment phases. Interreader agreement was assessed by intraclass correlation coefficient (ICC).Results: Kruskal-Wallis test showed significant differences between MD values among all the experiment phases, by both independent readers (1st: X2 [3,76]=17.16, PX2 [3,76]=15.88, PPost hoc analysis revealed differences in MD values by both readers between: rest-1 vs. contraction-1 (least P

Wilms tumor; Pediatric; Renal tumor Tumor de Wilms; Pediatría; Tumor renal Tumor de Wilms; Pediatria; Tumor renal Background: The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. Purpose: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. Study type: Consensus process using a Delphi method. Population: Not applicable. Field strength/sequence: Abdominal MRI including T1- and T2-weighted imaging, contrast-enhanced MRI, and diffusion-weighted imaging at 1.5 or 3 T. Assessment: Twenty-three radiologists from the SIOP-RTSG radiology panel with ≥5 years of experience in MRI of pediatric renal tumors and/or who had assessed ≥50 MRI scans of pediatric renal tumors in the past 5 years identified potentially discriminatory characteristics in the first questionnaire. These characteristics were scored in the subsequent second round, consisting of 5-point Likert scales, ranking- and multiple choice questions. Statistical tests: The cut-off value for consensus and agreement among the majority was ≥75% and ≥60%, respectively, with a median of ≥4 on the Likert scale. Results: Consensus on specific characteristics mainly concerned the discrimination between WTs and non-WTs, and WTs and nephrogenic rest(s) (NR)/nephroblastomatosis. The presence of bilateral lesions (75.0%) and NR/nephroblastomatosis (65.0%) were MRI characteristics indicated as specific for the diagnosis of a WT, and 91.3% of the participants agreed that MRI is useful to distinguish NR/nephroblastomatosis from WT. Furthermore, all participants agreed that age influenced their prediction in the discrimination of pediatric renal tumors. Data conclusion: Although the discrimination of pediatric renal tumors based on MRI remains challenging, this study identified some specific characteristics for tumor subtypes, based on the shared opinion of experts. These results may guide future validation studies and innovative efforts. This work was supported by a grant (Grant Number 341) from the Stichting Kinderen Kankervrij (KiKa).

Dignity of Small Renal Masses: Implications for Diagnostics and Therapy

Nierentumoren im Kindesalter werden nach Vorgaben der Renal Tumor Study Group der Internationalen Gesellschaft fur padiatrische Onkologie (RTSG-SIOP) behandelt. Der haufigste renale Tumor im Kindesalter ist das Nephroblastom. Die Magnetresonanztomographie (MRT) ist nach der Sonographie die bevorzugte bildgebende Methode. Die Aufgabe der Bildgebung umfasst die Differenzialdiagnose renaler Tumoren im Kindesalter anhand epidemiologischer und morphologischer Kriterien. Neu ist die Einfuhrung der Thorax-Computertomographie (CT) in der initialen Diagnostik. Neue Studien zu Nephroblastomsubtypen mit Diffusionsbildgebung (DWI) zeigen, dass durch Auswertungen des ADC(„apparent diffusion coefficient“)-Histogramms blastemreiche und anaplastische High-risk-Tumoren zu differenzieren sind. Bildgebende Kriterien zur nierenerhaltenden chirurgischen Therapie sind aktuell festgelegt und erlauben eine individuelle Therapie bei unilateralen, aber insbesondere bei bilateralen Tumoren. Differenzialdiagnosen sind neben dem kongenitalen mesoblastischen Nephrom, der Rhabdoidtumor, das Klarzellsarkom und das Nierenzellkarzinom. Herausfordernd ist die Diagnose nephrogener Reste und der Nephroblastomatose. Durch standardisierte Bildgebung verbessert sich Diagnostik und Therapie renaler Tumoren im Kindesalter, und neue prognostische Marker konnen zukunftig in der Bildgebung etabliert werden.

Background Recent studies have reported the additive value of combined gallium 68 (68Ga)-labeled Glu-urea-Lys (Ahx)-HBED-CC ligand targeting the prostate-specific membrane antigen (PSMA) (hereafter called 68Ga-PSMA-11) PET/MRI for the detection and localization of primary prostate cancer compared with multiparametric MRI. Purpose To compare the diagnostic accuracy and interrater agreement of multiparametric MRI and 68Ga-PSMA-11 PET/MRI for the detection of extracapsular extension (ECE) and seminal vesicle infiltration (SVI) in patients with prostate cancer. Materials and Methods Retrospective analysis of 40 consecutive men who underwent multiparametric MRI and 68Ga-PSMA-11 PET/MRI within 6 months for suspected prostate cancer followed by radical prostatectomy between April 2016 and July 2018. Four readers blinded to clinical and histopathologic findings rated the probability of ECE and SVI at multiparametric MRI and PET/MRI by using a five-point Likert-type scale. The prostatectomy specimen served as the reference standard. Accuracy was assessed with a multireader multicase analysis and by calculating reader-average areas under the receiver operating characteristics curve (AUCs), sensitivity, and specificity for ordinal and dichotomized data in a region-specific and patient-specific approach. Interrater agreement was assessed with the Fleiss multirater κ. Results For multiparametric MRI versus PET/MRI in ECE detection, respectively, AUC, sensitivity, and specificity in the region-specific analysis were 0.67 and 0.75 (P = .07), 28% (21 of 76) and 47% (36 of 76) (P = .09), and 94% (529 of 564) and 90% (509 of 564) (P = .007). For the patient-specific analysis, AUC, sensitivity, and specificity were 0.66 and 0.73 (P = .19), 46% (22 of 48) and 69% (33 of 48) (P = .04), and 75% (84 of 112) and 67% (75 of 112) (P = .19), respectively. For multiparametric MRI versus PET/MRI in SVI detection, respectively, AUC, sensitivity, and specificity of the region-specific analysis were 0.66 and 0.74 (P = .21), 35% (seven of 20) and 50% (10 of 20) (P = .25), and 98% (295 of 300) and 94% (282 of 300) (P < .001). For the patient-specific analysis, AUC, sensitivity, and specificity were 0.65 and 0.79 (P = .25), 35% (seven of 20) and 55% (11 of 20) (P = .20), and 98% (137 of 140) and 94% (131 of 140) (P = .07), respectively. Interrater reliability for multiparametric MRI versus PET/MRI did not differ for ECE (κ, 0.46 vs 0.40; P = .24) and SVI (κ, 0.23 vs 0.33; P = .39). Conclusion Our results suggest that gallium 68 (68Ga)-labeled Glu-urea-Lys (Ahx)-HBED-CC ligand targeting the prostate-specific membrane antigen (PSMA) (68Ga-PSMA-11) PET/MRI and multiparametric MRI perform similarly for local staging of prostate cancer in patients with intermediate-to-high-risk prostate cancer. The increased sensitivity of 68Ga-PSMA-11 PET/MRI for the detection of extracapsular disease comes at the cost of a slightly reduced specificity. © RSNA, 2019.

To analyze routine preoperative prostate MRI to predict erectile function (EF) before and after radical prostatectomy (RP).Patients who underwent RP with an existing preoperative MRI including dynamic contrast-enhanced images and completed International Index of Erectile Function (IIEF-5) questionnaires at baseline and 12 months postoperative. They were divided into four erectile dysfunction (ED) groups according to preoperative IIEF-5 score. The perfusion quality was measured in the peripheral zone of the prostate by the ratio of signal increase 120 s after wash-in of contrast agent (Ratio120) in preoperative MRI and compared between the ED groups.Ratio120 showed differences among the preoperative ED groups (Preoperative MRI of the prostate may be used for the prediction of EF and postsurgical recovery after RP. This may serve as important tool in preoperative patient counseling and management of expectations.

Purpose To assess the value of diffusion-weighted MRI (DW-MRI) in the non-invasive prediction of blastemal remnant after neoadjuvant chemotherapy in nephroblastoma. Methods This IRB-approved study included 32 pediatric patients with 35 tumors who underwent DW-MRI prior and after completion of neoadjuvant chemotherapy and subsequent surgical resection. Two blinded radiologists volumetrically assessed each tumor on pre- and post-neoadjuvant images and the parameters mean ADC, median ADC, 12.5th/25th/75th ADC percentile, skewness, and kurtosis were calculated. Blastemal remnant was determined per the pathology report. Associations between imaging features and blastemal remnant quartiles were examined using the Kruskal–Wallis test and adjusted for false discovery rate. Results Inter-reader agreement was high for mean ADC, skewness, kurtosis, and volume (ICC: 0.76–0.998). Pre-therapeutic histogram parameters skewness and kurtosis were found to be higher in patients with a higher amount of blastemal remnant for reader 1 (overall p = 0.035) and for kurtosis in reader 2 (overall p = 0.032) with skewness not reaching the level of statistical significance (overall p = 0.055). Higher tumor volume on pre-treatment imaging was associated with a higher amount of blastemal remnant after therapy (overall p = 0.032 for both readers). Conclusions Pre-treatment skewness and kurtosis of ADC histogram analysis were significantly associated with a larger fraction of a blastemal remnant after neoadjuvant chemotherapy. These findings could be incorporated into a more personalized chemotherapeutic regime in these patients and offer prognostic information at the time of initial diagnosis.

Background In testicular cancer determination of clinical stage and recommendation of therapeutic strategy after inguinal orchiectomy are based on primary imaging by CT-scan of the chest and CT- or MRI- abdomen. It has not been investigated so far, whether the imaging should be performed before or after primary testicular surgery. Staging before surgery means exposing all patients to CT radiation irrespective of ensured histologic malignancy while postoperative staging could pose a risk in biased clinical decision making by increased presence of unspecific lymph node enlargement caused by postsurgical effects. Therefore, we aimed to investigate the association between the timing of initial staging and occurrence of unspecific lymph node enlargement and adjuvant therapies after inguinal orchiectomy. Methods We retrospectively evaluated clinical and radiological data from 236 patients who had undergone inguinal orchiectomy for testicular cancer at our department. Statistical analysis was performed to determine whether the occurrence of unspecific lymph node enlargement or the rate of adjuvant therapies were influenced by timing of initial staging (preoperative vs. postoperative). Results The postoperative imaging cohort showed significant more inguinal, pelvic and retroperitoneal unspecific lymph node enlargement than the preoperative imaging cohort. Simultaneous occurrence of inguinal or pelvic lymph node enlargement together with retroperitoneal enlargements could only be found in the postoperative imaging cohort. No difference regarding adjuvant therapies could be found. Conclusions Timing of imaging affects the detection rate of unspecific lymph node enlargements but does not show a significant effect on the rate of adjuvant therapies.

Zusammenfassung. Die breite Verfügbarkeit radiologischer Diagnostik führt zur vermehrten Diagnose renaler Inzidentalome mit einem Durchmesser

Background Bowel preparation before multiparametric MRI (mpMRI) of the prostate is performed widely, despite contradictory or no evidence for efficacy. Purpose To investigate the value of hyoscine N-butylbromide (HBB), microenema (ME) and ‘dietary restrictions’ (DR) for artifact reduction and image quality (IQ) in mpMRI of the prostate. Study type Retrospective. Population Between 10/2018 and 02/2020 treatment-naïve men (median age, 64.9; range 39.8–87.3) who underwent mpMRI of the prostate were included. The total patient sample comprised of n = 180 patients, who received either HBB, ME, were instructed to adhere to DR, or received a combination of those measures prior to the MR scan. Field strength/sequence T2-weighted imaging (T2w), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced MRI (DCE-MRI) scanned on two 3T systems. Assessment A radiologist specialized in urogenital imaging (R1) and a senior radiology resident (R2) visually assessed IQ parameters on transversal T2w, DWI and ADC maps on a 5-point Likert-like scale. Statistical tests Group comparison between IQ parameters was performed on reader level using Kruskal–Wallis and Mann–Whitney U tests. Binary univariate logistic regression analysis was used to assess independent predictors of IQ. Interrater agreement was assessed using Intraclass Correlation Coefficient (ICC). Results ‘DWI geometric distortion’ was significantly more pronounced in the HBB+/ME−/DR− (R1, 3.6 and R2, 4.0) as compared to the HBB−/ME+/DR− (R1, 4.2 and R2, 4.6) and HBB+/ME+/DR− (R1, 4.3 and R2, 4.7) cohort, respectively. Parameters ‘DWI IQ’ and ‘Whole MRI IQ’ were rated similarly by both readers. ME was a significant independent predictor of ‘good IQ’ for the whole MRI for R1 [b = 1.09, OR 2.98 (95% CI 1.29, 6.87)] and R2 [b = 1.01, OR 2.73 (95% CI 1.24, 6.04)], respectively. Data conclusion ME seems to significantly improve image quality of DWI and the whole mpMRI image set of the prostate. HBB and DR did not have any benefit.

Proposal of a systematic approach to assess Deep infiltrating endometriosis (DIE) through pelvic Magnetic resonance imaging (MRI) using the Enzian classification and examination of inter-rater agreement. Three radiologists reviewed 23 MRI of patients with pelvic DIE at one tertiary referral center retrospectively and independently. Inclusion criteria were intraoperative confirmation of DIE and MR imaging according to ESUR (European Society of Urogenital Radiology) guidelines. Assessment of the anatomical pelvic compartments was performed using a manual based on the Enzian classification with step-by-step instructions using recommended planes and sequences presented here. Interrater agreement was measured using kappa statistics. According to the intraoperative site lesions in 53 anatomical compartments were present. Interrater agreement was best for compartments A (0.255) and FB (0.642). For FI (0.204) and B (0.146) it was slight, there was poor agreement for C (− 0.263), FA (− 0.022), and FO (− 0.030), respectively, and as for FU, no ureter infiltration was described. MRI as a noninvasive diagnostic tool offers essential advantages regarding classification and therapy planning for patients with DIE. However, its assessment is difficult and a more systematic approach is needed. Our proposed manual based on the Enzian classification is reproducible and could support radiologists and gynecologists.

PurposeTo assess the value of the PI-RADS 2.1 scoring system in the detection of prostate cancer on multiparametric MRI in comparison to the standard PI-RADS 2.0 system and to assess its inter-reader variability.Materials and methodsThis IRB-approved study included 229 patients undergoing multiparametric prostate MRI prior to MRI-guided TRUS-based biopsy, which were retrospectively recruited from our prospectively maintained institutional database. Two readers with high (reader 1, 6 years) and low (reader 2, 2 years) level of expertise identified the lesion with the highest PI-RADS score for both version 2.0 and 2.1 for each patient. Inter-reader agreement was estimated, and diagnostic accuracy analysis was performed.ResultsInter-reader agreement on PI-RADS scores was fair for both version 2.0 (kappa: 0.57) and 2.1 (kappa: 0.51). Detection rates for prostate cancer (PCa) and clinically significant prostate cancer (csPCa) were almost identical for both PI-RADS versions and higher for the more experienced reader (AUC, Reader 1: PCa, 0.881-0.887, csPCa, 0.874-0.879; Reader 2: PCa, 0.765, csPCa, 0.746-0.747; both p > 0.05), both when using a PI-RADS score of ≥ 4 and ≥3 as indicators for positivity for cancer.ConclusionsThe new PI-RADS 2.1 scoring system showed comparable diagnostic performance and inter-reader variability compared to version 2.0. The introduced changes in the version 2.1 seem only to take effect in a very small number of patients.

Purpose: To investigate associations between imaging features of tumors and age, gender and body mass index (BMI) in patients with renal cell carcinoma. Method: This IRB-approved, HIPAA-compliant study included 1348 patients with histopathologically confirmed renal cell carcinoma of the clear cell subtype (ccRCC, n = 904) or non-clear cell subtype (n = 444), who underwent pre-treatment CT imaging less than 180 days before nephrectomy between 1999 and 2011. Two radiologists independently, retrospectively analyzed all imaging studies and identified features (necrosis, renal vein invasion, contact with renal sinus fat, multicystic appearance and nodular enhancement), which were then correlated with patient age, gender and BMI at time of surgery. Results: Inter-reader agreement on imaging features ranged from substantial to excellent (kappa: 0.688 to 0.982). In the ccRCC group, multicystic tumor appearance was significantly associated with lower patient age (p < 0.05) and lower BMI (p < 0.05); the presence of renal vein invasion was significantly associated with lower BMI in males (p < 0.05); and both tumor contact with the renal sinus and nodular enhancement were significantly associated with greater patient age (p < 0.05). In the non-clear cell RCC group, necrosis was associated with lower BMI for females (p < 0.05). Conclusions: This study demonstrated significant associations between imaging features of RCC and patient age and BMI, hinting an influence of these factors on tumor biology and genomic make-up. These findings could aid future studies in selecting patients while investigating genomic, molecular and metabolic variables in RCC and might potentially impact on future stratification and therapy of patients.

PURPOSE Comparing mpMRI and 68Ga-PSMA-PET/MRI in primary staging of PCa and investigating the value of quantitative mpMRI-measurements for prediction of extracapsular extension and N-metastases. METHODS Patients with PCa undergoing 68Ga-PSMA-PET/MRI and mpMRI during January 2016 to February 2019 were retrospectively included. Two readers each on 68Ga-PSMA-PET/MRI or mpMRI rated extraprostatic extension (≥T3) and regional lymph-node-metastasis (N1) on a Likert-scale. A fifth reader measured tumor volume, maximum diameter, and capsular contact length on mpMRI. Probability of lymph-node-metastasis was additionally calculated using the 2018 Briganti model. Interobserver-agreement was assessed by squared Cohen's kappa, and diagnostic accuracy was determined using radical prostatectomy (n = 35/49) as reference standard. RESULTS 49 patients (median age 66 years [IQR: 61-72 years]) were evaluated. Interobserver-agreement for mpMRI and 68Ga-PSMA-PET/MRI was: ≥T3: κ = 0.58/0.47; N1: κ = 0.55/0.92. Diagnostic accuracy for mpMRI vs 68Ga-PSMA-PET/MRI readers for ≥ T3 was AUC: 0.72, 0.62 vs 0.71, 0.72 (p > 0.38) and for N1 was AUC: 0.39, 0.55 vs 0.72, 0.78 (p

To determine the appearance of rectal cancer on MRI after oxaliplatin-based chemotherapy (ICT) and make a preliminary assessment of MRI’s value in predicting response to total neoadjuvant treatment (TNT). In this IRB-approved, HIPAA-compliant, retrospective study between 1 January 2010–20 October 2014, pre- and post-ICT tumour T2 volume, relative T2 signal intensity (rT2SI), node size, signal intensity and border characteristics were assessed in 63 patients (65 tumours) by three readers. The strength of association between the reference standard of histopathological percent tumour response and tumour volume change, rT2SI and lymph node characteristics was assessed with Spearman’s correlation coefficient and Wilcoxon’s rank sum test. Cox regression was used to assess association between DFS and radiological measures. Change in T2 volume was not associated with TNT response. Change in rT2SI showed correlation with TNT response for one reader only using selective regions of interest (ROIs) and borderline correlation with response using total volume ROI. There was a significant negative correlation between baseline and post-ICT node size and TNT response (r = -0.25, p = 0.05; r = -0.35, p = 0.005, readers 1 and 2, respectively). Both baseline and post-induction median node sizes were significantly smaller in complete responders (p = 0.03, 0.001; readers 1 and 2, respectively). Change in largest baseline node size and decrease in post-ICT node signal heterogeneity were associated with 100% tumour response (p = 0.04). Nodal sizes at baseline and post-ICT MRI correlated with DFS. In patients undergoing post-ICT MRI, tumour volume did not correlate with TNT response, but decreased lymph node sizes were significantly associated with complete response to TNT as well as DFS. Relative T2SI showed borderline correlation with TNT response. • MRI-based tumour volume after induction chemotherapy and before chemoradiotherapy did not correlate with overall tumour response at the end of all treatment. • Lymph node size after induction chemotherapy and before chemoradiotherapy was strongly associated with complete pathological response after all treatment. • Lymph node sizes at baseline and post-induction chemotherapy MRI correlated with disease-free survival.

We evaluated the outcomes of surgical intervention and active surveillance in patients diagnosed with cystic renal cell carcinoma at our hypothesized radiological cutoff of greater than 50% cystic.We identified all 430 patients with a pathologically confirmed cystic renal mass that fit our criteria from 2000 to 2015. The 292 patients with a lack of computerized tomography, tumors less than 50% cystic on imaging, multifocal tumors and prior renal cell carcinoma were excluded from study. Patients were stratified into benign or malignant subgroups, and radiological, clinicopathological and oncologic features were determined. Univariate and multivariate associations between clinicoradiological parameters in each group were analyzed. We similarly reviewed the records of a separate cohort of patients treated with active surveillance for cystic renal cell carcinoma.Of the 138 identified cases of cystic renal cell carcinoma 102 (73.9%) were renal cell carcinoma and 36 (26.1%) were benign masses. Of the tumors 77.5% were Fuhrman grade 1-2, 83.4% were stage pT2 or less and 65.9% showed clear cell histology. On univariate analysis male gender, a solid component and increasing Bosniak classification were significant for malignancy. In a separate cohort we identified 38 patients on active surveillance. The growth rate was 1.0 mm per year overall and 2.3 mm per year for the solid component. At a median followup of more than 4 years in all cohorts there was no evidence of recurrence or metastasis of cystic renal cell carcinoma.Patients with unifocal cystic renal cell carcinoma evaluated using a standardized radiological threshold of greater than 50% cystic had an excellent prognosis on active surveillance and after surgical resection.

The purpose of our study was to retrospectively evaluate and categorize temporal changes in MRI appearances of the prostate in patients who underwent focal therapy with MRI follow-up. The Institutional Review Board approved this retrospective study and waived the requirement for informed consent. Thirty-seven patients (median age 61; 48–70 years) with low-to-intermediate-risk, clinically organ-confined prostate cancer underwent focal ablation therapy from 2009 to 2014. Two radiologists reviewed post-treatment MRIs (n = 76) and categorized imaging features blinded to the time interval between the focal therapy and the follow-up MRI. Inter-reader agreement was assessed (kappa) and generalized linear regression was used to examine associations between an imaging feature being present/absent and days between ablation and MRI. Inter-reader agreement on MRI features ranged from fair to substantial. Edema was found present at earlier times after ablation (median 16–25 days compared to MRIs without edema, median 252–514 days), as was rim enhancement of the ablation zone (18–22.5 days vs. 409–593 days), a hypointense rim around the ablation zone on T2-weighted images (53-57.5 days vs. 279–409 days) and the presence of an appreciable ablation cavity (48.5–60 days vs. 613–798 days, all p

Purpose To assess the abilities of the standard mono-exponential (ME), bi-exponential (BE), diffusion kurtosis (DK) and stretched exponential (SE) models to characterize diffusion signal in malignant and prostatic tissues and determine which of the four models best characterizes these tissues on a per-voxel basis. Materials and methods This institutional-review-board-approved, HIPAA-compliant, retrospective study included 55 patients (median age, 61 years; range, 42–77 years) with untreated, biopsy-proven PCa who underwent endorectal coil MRI at 3-Tesla, diffusion-weighted MRI acquired at eight b-values from 0 to 2000 s/mm2. Estimated parameters were apparent diffusion coefficent (ME model); diffusion coefficients for the fast (Dfast) and slow (Dslow) components and fraction of fast component, ffast (BE model); diffusion coefficient D, and kurtosis K (DK model); distributed diffusion coefficient DDC and α for (SE model). For one region-of-interest (ROI) in PZ and another in PCa in each patient, the corrected Akaike information criterion (AICc) and the Akaike weight (w) were calculated for each voxel. Results Based on AICc and w, all non-monoexponential models outperformed the ME model in PZ and PCa. The DK model in PZ and SE model in PCa ROIs best fit the greatest average percentages of voxels (39% and 43%, respectively) and had the highest mean w (35 ± 16 × 10− 2 and 41 ± 22 × 10− 2, respectively). Conclusion DK and SE models best fit DWI data in PZ and PCa, and non-ME models consistently outperformed the ME model. Voxel-wise mapping of the preferential model demonstrated that the vast majority of voxels in either tissue type were best fit with one of the non-monoexponential models. At the given SNR levels, the maximum b-value of 2000 s/mm2 is not sufficiently high to identify the preferred non-monoexponential model.

To determine the value of novel whole tumor metrics in DWI-MRI and DCE-MRI of rectal cancer treatment assessment. This retrospective study included 24 uniformly treated patients with rectal adenocarcinoma who underwent MRI including diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) sequences, before and after chemoradiotherapy. Two experienced readers independently measured tumor volume and apparent diffusion coefficient (ADC) on DWI-MRI and tumor volume and transfer constant K trans on DCE-MRI. In addition, we explored and defined Total Lesion Diffusion (TLD) as Total DWI tumor volume multiplied by mean volumetric ADC and Total Lesion Perfusion (TLP) as the total DCE tumor volume multiplied by the mean volumetric K trans. These metrics were correlated with histopathologic percent tumor regression in the resected specimen (%TR). Inter-reader agreement was assessed using the concordance correlation coefficient (CCC). For both readers, post-treatment TLP revealed comparable correlations with %TR compared with K trans (reader 1; Spearman’s rho = − 0.36 vs. − 0.32, reader 2; Spearman’s rho = − 0.32 vs. − 0.28). In addition, TLP afforded the highest inter-reader agreement at post-treatment among TLP, DCE vol, and K trans (CCC: 0.64 vs. 0.36 vs. 0.35). Post-treatment TLD showed similar correlation with %TR as DWI volume in reader 1 and superior correlation with %TR for reader 2 (reader 1; Spearman’s rho − 0.56 vs. − 0.57, reader 2; Spearman’s rho − 0.59 vs. − 0.45). The novel tumor metrics TLD and TLP revealed similar results to established metrics for correlation with tumor response with equivalent or superior inter-reader agreements and we recommend that these be studied in larger trials.

To assess the value of new magnetic resonance imaging (MRI) techniques in cervical cancer. We searched PubMed and MEDLINE and reviewed articles published from 1990 to 2016 to identify studies that used MRI techniques, such as diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM) and dynamic contrast enhancement (DCE) MRI, to assess parametric invasion, to detect lymph node metastases, tumour subtype and grading, and to detect and predict tumour recurrence. Seventy-nine studies were included. The additional use of DWI improved the accuracy and sensitivity of the evaluation of parametrial extension. Most studies reported improved detection of nodal metastases. Functional MRI techniques have the potential to assess tumour subtypes and tumour grade differentiation, and they showed additional value in detecting and predicting treatment response. Limitations included a lack of technical standardisation, which limits reproducibility. New advanced MRI techniques allow improved analysis of tumour biology and the tumour microenvironment. They can improve TNM staging and show promise for tumour classification and for assessing the risk of tumour recurrence. They may be helpful for developing optimised and personalised therapy for patients with cervical cancer. • Conventional MRI plays a key role in the evaluation of cervical cancer. • DWI improves tumour delineation and detection of nodal metastases in cervical cancer. • Advanced MRI techniques show promise regarding histological grading and subtype differentiation. • Tumour ADC is a potential biomarker for response to treatment.

Die transrektale Sonografie mit systematischer Biopsie gilt derzeit als Standard fur die Diagnose eines Prostatakarzinoms. Allerdings ist das Verfahren nicht immer prazise – hochgradige Erkrankungen konnen ubersehen und niedrig maligne Veranderungen ubertherapiert werden. Die Fusionsbiopsie konnte eine Alternative darstellen, aber dazu muss sie zuverlassig reproduzierbar sein. Das haben Mediziner aus den USA gepruft.

To assess the performance of the updated Prostate Imaging Reporting and Data System (PI-RADSv2) and the apparent diffusion coefficient (ADC) for predicting confirmatory biopsy results in patients considered for active surveillance of prostate cancer (PCA). IRB-approved, retrospective study of 371 consecutive men with clinically low-risk PCA (initial biopsy Gleason score ≤6, prostate-specific antigen

The purpose of this study was to develop a quantitative multiparametric MRI approach to differentiating clear cell renal cell carcinoma (RCC) from other renal cortical tumors.This retrospective study included 119 patients with 124 histopathologically confirmed renal cortical tumors who underwent preoperative MRI including DWI, contrast-enhanced, and chemical-shift sequences before nephrectomy. Two radiologists independently assessed each tumor volumetrically, and apparent diffusion coefficient values, parameters from multiphasic contrast-enhanced MRI (peak enhancement, upslope, downslope, AUC), and chemical-shift indexes were calculated. Univariate and multivariable logistic regression analyses were performed to identify parameters associated with clear cell RCC.Interreader agreement was excellent (intraclass correlation coefficient, 0.815-0.994). The parameters apparent diffusion coefficient (reader 1 AUC, 0.804; reader 2, 0.807), peak enhancement (reader 1 AUC, 0.629; reader 2, 0.606), and downslope (reader 1 AUC, 0.575; reader 2, 0.561) were significantly associated with discriminating clear cell RCC from other renal cortical tumors. The combination of all three parameters further increased diagnostic accuracy (reader 1 AUC, 0.889; reader 2, 0.907; both p ≤ 0.001), yielding sensitivities of 0.897 for reader 1 and 0.897 for reader 2, and specificities of 0.762 for reader 1 and 0.738 for reader 2 in the identification of clear cell RCC. With maximized sensitivity, specificities of 0.429 and 0.262 were reached for readers 1 and 2, respectively.A quantitative multiparametric approach statistically significantly improves diagnostic performance in differentiating clear cell RCC from other renal cortical tumors.

We sought to externally validate recently published prostate cancer risk calculators incorporating multiparametric magnetic resonance imaging to predict clinically significant prostate cancer. We also compared the performance of these calculators to that of multiparametric magnetic resonance imaging naïve prostate cancer risk calculators.We identified men without a previous prostate cancer diagnosis who underwent transperineal template saturation prostate biopsy with fusion guided targeted biopsy between November 2014 and March 2018 at our academic tertiary referral center. Any Gleason pattern 4 or greater was defined as clinically significant prostate cancer. Predictors, which were patient age, prostate specific antigen, digital rectal examination, prostate volume, family history, previous prostate biopsy and the highest region of interest according to the PI-RADS™ (Prostate Imaging Reporting and Data System), were retrospectively collected. Four multiparametric magnetic resonance imaging prostate cancer risk calculators and 2 multiparametric magnetic resonance imaging naïve prostate cancer risk calculators were evaluated for discrimination, calibration and the clinical net benefit using ROC analysis, calibration plots and decision curve analysis.Of the 468 men 193 (41%) were diagnosed with clinically significant prostate cancer. Three multiparametric magnetic resonance imaging prostate cancer risk calculators showed similar discrimination with a ROC AUC significantly higher than that of the other prostate cancer risk calculators (AUC 0.83-0.85 vs 0.69-0.74). Calibration in the large showed 2% deviation from the true amount of clinically significant prostate cancer for 2 multiparametric magnetic resonance imaging risk calculators while the other calculators showed worse calibration at 11% to 27%. A clinical net benefit was observed only for 3 multiparametric magnetic resonance imaging risk calculators at biopsy thresholds of 15% or greater. None of the 6 investigated prostate cancer risk calculators demonstrated clinical usefulness against a biopsy all strategy at thresholds less than 15%.The performance of multiparametric magnetic resonance imaging prostate cancer risk calculators varies but they generally outperform multiparametric magnetic resonance imaging naïve prostate cancer risk calculators in regard to discrimination, calibration and clinical usefulness. External validation in other biopsy settings is highly encouraged.

To assess interreader agreement of manual prostate cancer lesion segmentation on multiparametric MR images (mpMRI). The secondary aim was to compare tumor volume estimates between MRI segmentation and transperineal template saturation core needle biopsy (TTSB). We retrospectively reviewed patients who had undergone mpMRI of the prostate at our institution and who had received TTSB within 190 days of the examination. Seventy-eight cancer lesions with Gleason score of at least 3 + 4 = 7 were manually segmented in T2-weighted images by 3 radiologists and 1 medical student. Twenty lesions were also segmented in apparent diffusion coefficient (ADC) and dynamic contrast enhanced (DCE) series. First, 20 volumetric similarity scores were computed to quantify interreader agreement. Second, manually segmented cancer lesion volumes were compared with TTSB-derived estimates by Bland-Altman analysis and Wilcoxon testing. Interreader agreement across all readers was only moderate with mean T2 Dice score of 0.57 (95%CI 0.39–0.70), volumetric similarity coefficient of 0.74 (0.48–0.89), and Hausdorff distance of 5.23 mm (3.17–9.32 mm). Discrepancy of volume estimate between MRI and TTSB was increasing with tumor size. Discrepancy was significantly different between tumors with a Gleason score 3 + 4 vs. higher grade tumors (0.66 ml vs. 0.78 ml; p = 0.007). There were no significant differences between T2, ADC, and DCE segmentations. We found at best moderate interreader agreement of manual prostate cancer segmentation in mpMRI. Additionally, our study suggests a systematic discrepancy between the tumor volume estimate by MRI segmentation and TTSB core length, especially for large and high-grade tumors. • Manual prostate cancer segmentation in mpMRI shows moderate interreader agreement. • There are no significant differences between T2, ADC, and DCE segmentation agreements. • There is a systematic difference between volume estimates derived from biopsy and MRI.

Background Recent studies have reported the additive value of combined gallium 68 (

Purpose To compare the correlation of transition zone prostate-specific antigen density (TZPSAD) versus whole gland (WG) density (PSAD) with Gleason score. Methods In this single-center, retrospective cohort study, men undergoing MRI of the prostate in 2015 and 2016 who had a transperineal template saturation biopsy within 6 months of MRI were included (n = 178; median age 64 y, interquartile range [IQR] 58–68 y; PSA 6.6 ng/ml, 4.6–9.7 ng/ml). The WG and TZ were segmented voxel-wise on T2-weighted transverse planes. The volumes and corresponding PSA-densities were calculated. Correlations with the Gleason score were assessed with Spearman’s rho. Optimal thresholds of the PSA densities were computed using the Youden Index of the receiver-operating-characteristics curve. A p-value of ≤ 0.05 was considered statistically significant. Results Median WG volume was 45 ml (IQR: 33.9–58.7 ml, range: 17.2–165.3 ml), median volume of the TZ was 27.3 ml (IQR: 19.2–39.3 ml, range: 9.0–141.1 ml). Both PSA density values, PSAD and TZPSAD, correlated significantly with the Gleason score: The PSAD (rho = 0.39) showed significantly weaker correlation than the TZPSAD (rho = 0.44, p = 0.05). ROC analysis revealed an ideal cut-off of 0.15 ng/ml2 for PSAD (95%-CI: 0.09–0.16 ng/ml2) and 0.22 ng/ml2 for the TZPSAD (0.15-0.32 ng/ml2) for discrimination between Gleason 3 + 4 and 4 + 3. Conclusion The TZPSAD exhibited a stronger correlation with cancer dedifferentiation than PSAD and may thus be a better surrogate marker for cancer aggressiveness than PSAD. Moreover, the TZPSAD threshold of 0.22 ng/ml2 may help in risk stratification of men with suspected PCa.

To evaluate the role of preoperative multiparametric magnetic resonance imaging (MRI) as predictor of post-prostatectomy incontinence (PPI). We analyzed patients who underwent robot-assisted radical prostatectomy for localized prostate cancer at our institution between July 2015 and April 2017. In these patients, we measured the perfusion quality of the pelvic floor with contrast media kinetics in the preoperative MRI of the prostate and compared the levator ani muscle (region of interest) to the surrounding pelvic muscle structures (reference). Prospectively collected questionnaires regarding urinary incontinence were then evaluated 1 year postoperatively. Outcomes were dichotomized into “continent” (ICIQ-Score = 0–5) and “incontinent” (ICIQ-Score ≥ 6). In each patient, we determined the perfusion ratio of the levator ani muscle divided by the surrounding pelvic muscle structures and compared them among the groups. Forty-two patients were included in the study (n = 22 in “continent”, n = 20 in “incontinent” group). The median perfusion ratio from the continent group was significantly higher compared to the incontinent group (1.61 vs. 1.15; 95% CI 0.09–0.81, p = 0.015). The median perfusion ratio in “excellent” (ICIQ-Score = 0) was significantly higher than in “poor” (ICIQ-Score ≥ 11) outcomes (1.48 vs. 0.94; 95% CI 0.04–1.03, p = 0.036). Further, a higher perfusion ratio was negatively correlated with ICIQ-Score (r = − 0.33; 95% CI − 0.58 to 0.03; p = 0.031). Our data demonstrate a promising new strategy to predict PPI through the perfusion quality of pelvic muscle structures with contrast media kinetics. This may facilitate preoperative patient consulting and decision-making.

OBJECTIVE. The objective of this study was to develop a scoring system for background signal intensity changes or prostate homogeneity on prostate MRI and to assess these changes’ influence on cancer detection. MATERIALS AND METHODS. This institutional review board–approved, HIPAA-compliant, retrospective study included 418 prostate MRI examinations in 385 men who subsequently underwent MRI-guided biopsy. The Likert score for suspicion of cancer assigned by the primary radiologist was extracted from the original report, and histopathologic work-up of the biopsy cores served as the reference standard. Two readers assessed the amount of changes on T2-weighted sequences and assigned a predefined prostate signal-intensity homogeneity score of 1–5 (1 = poor, extensive changes; 5 = excellent, no changes). The sensitivity and specificity of Likert scores for detection of prostate cancer and clinically significant cancer (Gleason score ≥ 3+4) were estimated in and compared between subgroups of patients with different signal-intensity homogeneity scores (≤ 2, 3, and ≥ 4). RESULTS. Interreader agreement on signal-intensity homogeneity scores was substantial (κ = 0.783). Sensitivity for prostate cancer detection increased when scores were better (i.e., higher) (reader 1, from 0.41 to 0.71; reader 2, from 0.53 to 0.73; p ≤ 0.007, both readers). In the detection of significant cancer (Gleason score ≥ 3+4), sensitivity also increased with higher signal-intensity scores (reader 1, from 0.50 to 0.82; reader 2, from 0.63 to 0.86; p ≤ 0.028), though specificity decreased significantly for one reader (from 0.67 to 0.38; p = 0.009). CONCLUSION. Background signal-intensity changes on T2-weighted images significantly limit prostate cancer detection. The proposed scoring system could improve the standardization of prostate MRI reporting and provide guidance for applying prostate MRI results appropriately in clinical decision-making.

Segmentation of anatomical structures and pathologies is inherently ambiguous. For instance, structure borders may not be clearly visible or different experts may have different styles of annotating. The majority of current state-of-the-art methods do not account for such ambiguities but rather learn a single mapping from image to segmentation. In this work, we propose a novel method to model the conditional probability distribution of the segmentations given an input image. We derive a hierarchical probabilistic model, in which separate latent variables are responsible for modelling the segmentation at different resolutions. Inference in this model can be efficiently performed using the variational autoencoder framework. We show that our proposed method can be used to generate significantly more realistic and diverse segmentation samples compared to recent related work, both, when trained with annotations from a single or multiple annotators., Comment: Accepted to MICCAI 2019

The objective of this study was to investigate whether the apparent diffusion coefficient (ADC) value from DWI and the forward volume transfer constant (K(trans)) value from dynamic contrast-enhanced MRI independently predict prostate cancer aggressiveness, and to determine whether the combination of both parameters performs better than either parameter alone in assessing tumor aggressiveness before treatment.This retrospective study included 158 men with histopathologically confirmed prostate cancer who underwent 3-T MRI before undergoing prostatectomy in 2011. Whole-mount step-section pathologic maps identified 195 prostate cancer foci that were 0.5 mL or larger; these foci were then volumetrically assessed to calculate the per-tumor ADC and K(trans) values. Associations between MRI and histopathologic parameters were assessed using Spearman correlation coefficients, univariate and multivariable logistic regression, and AUCs.The median ADC and K(trans) values showed moderate correlation only for tumors for which the Gleason score (GS) was 4 + 4 or higher (ρ = 0.547; p = 0.042). The tumor ADC value was statistically significantly associated with all dichotomized GSs (p0.005), including a GS of 3 + 3 versus a GS of 3 + 4 or higher (AUC, 0.693; p = 0.001). The tumor K(trans) value differed statistically significantly only between tumors with a GS of 3 + 3 and those with a primary Gleason grade of 4 (p ≤ 0.015), and it made a statistically significant contribution only in differentiating tumors with a GS of 4 + 3 or higher (AUC, 0.711; p0.001) and those with a GS of 4 + 4 or higher (AUC, 0.788; p0.001) from lower-grade tumors. Combining ADC and K(trans) values improved diagnostic performance in characterizing tumors with a GS of 4 + 3 or higher and those with a GS of 4 + 4 or higher (AUC, 0.739 and 0.856, respectively; p0.01).Although the ADC value helped to differentiate between all GSs, the K(trans) value was only a benefit in characterizing more aggressive tumors. Combining these parameters improves their performance in identifying patients with aggressive tumors who may require radical treatment.

Bevacizumab has shown benefit in the first-line setting in combination with interferon; however, data on use as monotherapy are limited. In this retrospective analysis of 71 patients we assessed the efficacy of bevacizumab monotherapy in patients whose disease progressed during treatment with other targeted drugs. Bevacizumab monotherapy resulted in prolonged disease control and few discontinuations for adverse events, including for patients who were heavily pretreated.Bevacizumab has shown benefit in the first-line treatment of metastatic clear cell renal cell carcinoma (ccRCC) in combination with interferon α. In this retrospective analysis we assessed the efficacy of bevacizumab monotherapy in patients whose disease progressed during treatment with vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors, and/or mammalian target of rapamycin inhibitors.A retrospective analysis was performed on metastatic ccRCC patients who received bevacizumab monotherapy after their disease progressed during treatment with previous targeted therapies. The primary objective was to assess overall survival (OS) and the secondary objectives includes progression-free survival (PFS), therapy duration, and incidence of serious adverse events assessed during visits to the Memorial Sloan Kettering Cancer Center (MSKCC) urgent care center.Seventy-one patients were treated with bevacizumab as monotherapy in the salvage setting. Most patients were heavily pretreated with 36 patients (51%) who received bevacizumab as a fourth-line or later agent, and 33 patients (46%) who received at least 2 previous VEGF targeted agents. Eighteen patients (25%) had a Karnofsky Performance Status (KPS)80%, and 20 patients (28%) were classified as poor risk according to MSKCC criteria. Median OS was 11.5 months (95% confidence interval [CI], 6.4-17.4), and median PFS was 1.9 months (95% CI, 1.7-4.1). Nine patients (13%) had a prolonged time of therapy of12 months. Four patients (6%) discontinued therapy because of adverse events. Poor KPS (80%) and MSKCC poor-risk classification were prognostic for poor OS with hazard ratios of 4.09 (P.001) and 2.84 (P = .021), respectively.Bevacizumab monotherapy resulted in prolonged disease control and few discontinuations because of adverse events in patients whose disease had progressed during treatment with other targeted therapies, including patients who were heavily pretreated.

The objective of this study was to investigate associations between CT features and survival in patients with clear cell renal cell carcinoma (ccRCC).The study included 763 patients with histopathologically confirmed ccRCC who underwent preoperative contrast-enhanced CT between 1999 and 2011. Imaging features, both qualitative (cystic tumor, necrosis, tumor contact with renal sinus, renal vein invasion, peritumoral stranding, and peritumoral neovascularity) and quantitative (maximal tumor diameter and distance from the tumor to the renal sinus), were evaluated. Univariate and multivariable Cox regressions were used to assess associations of imaging features with disease-specific survival (DSS) and disease-specific progression-free survival (PFS).Greater tumor size and the presence of renal vein invasion on CT were associated with decreased DSS and disease-specific PFS (p0.05), and the presence of extensive necrosis (more than two-thirds of the tumor volume) was associated with decreased disease-specific PFS (p0.05); this association remained statistically significant when we controlled for pathologic tumor stage. In contrast, no disease-specific death or progression was seen in patients with purely cystic tumors. Greater distance between the tumor and the renal sinus was not statistically significantly associated with longer survival.In patients with ccRCC, observation of extensive necrosis on CT was statistically significantly associated with decreased disease-specific PFS, whereas greater tumor size and the presence of renal vein invasion on CT were statistically significantly associated with decreased DSS and disease-specific PFS. No disease progression was observed in tumors with a cystic appearance. Therefore, selected CT features could potentially aid in risk assessment for and counseling of patients with ccRCC and could provide prognostic information beyond the established tumor staging system.

The purpose of this study was to differentiate clear cell renal cell carcinoma (RCC) from other common renal cortical tumors by use of DWI.The study included 117 patients (mean age, 60 years) with 122 histopathologically confirmed renal cortical tumors who underwent 1.5-T MRI that included DWI before they underwent nephrectomy between 2006 and 2013. For each tumor, two radiologists independently evaluated apparent diffusion coefficient (ADC) values on the basis of a single ROI in a nonnecrotic area of the tumor and also by assessment of the whole tumor. The concordance correlation coefficient (CCC) was calculated to assess interreader agreement. The mean ADC values of clear cell RCC and every other tumor subtype were compared using an exact Wilcoxon rank sum test.Interreader agreement was excellent and higher in whole-tumor assessment (CCC, 0.982) than in single-ROI analysis (CCC, 0.756). For both readers, ADC values for clear cell RCC found on single-ROI assessment (2.19 and 2.08 × 10(-3) mm(2)/s) and whole-tumor assessment (2.30 and 2.32 × 10(-3) mm(2)/s) were statistically significantly higher than those for chromophobe, papillary, or unclassified RCC (p0.05) but were similar to those for oncocytoma found on single-ROI assessment (2.14 and 2.32 × 10(-3) mm(2)/s) and whole-tumor assessment (2.38 and 2.24 × 10(-3) mm(2)/s). ADC values were also higher for clear cell RCC than for angiomyolipoma, but the difference was statistically significant only in whole-tumor assessment (p0.03).ADC values were statistically significantly higher for clear cell RCC than for chromophobe, papillary, or unclassified RCC subtypes; however, differentiating clear cell RCC from oncocytoma by use of DWI remains especially challenging, because similar ADC values have been shown for these two tumor types.

PURPOSE: To determine whether water diffusion and the perfusion fraction coefficients in prostate peripheral zone (PZ) and prostate cancer (PCa) are affected by intravenous contrast injection and explore the potential mechanism behind previously reported differences between pre- and post-contrast ADC values. METHODS: Our institutional review board waived informed consent for this HIPAA-compliant, retrospective study, which included 32 patients (median age, 63 years; range, 47–77 years) with biopsy-proven, untreated PCa who underwent 3-Tesla MRI, including DW-MRI at b-values 0, 400, 700, 1000 s/mm(2) before and after gadolinium injection. For regions of interest (ROIs) in presumed benign PZ and PZ PCa, apparent diffusion coefficent (ADC), perfusion fraction f, and diffusion coefficient D were estimated voxel-wise, and signal-to-noise ratio (SNR) and contrast-to-noise (CNR) were estimated. Pre- and post-contrast measurements were compared by Wilcoxon signed-rank test; P

Purpose To evaluate the interreader variability in prostate and seminal vesicle (SV) segmentation on T2w MRI. Methods Six readers segmented the peripheral zone (PZ), transitional zone (TZ) and SV slice-wise on axial T2w prostate MRI examinations of n = 80 patients. Twenty different similarity scores, including dice score (DS), Hausdorff distance (HD) and volumetric similarity coefficient (VS), were computed with the VISCERAL EvaluateSegmentation software for all structures combined and separately for the whole gland (WG = PZ + TZ), TZ and SV. Differences between base, midgland and apex were evaluated with DS slice-wise. Descriptive statistics for similarity scores were computed. Wilcoxon testing to evaluate differences of DS, HD and VS was performed. Results Overall segmentation variability was good with a mean DS of 0.859 (±SD = 0.0542), HD of 36.6 (±34.9 voxels) and VS of 0.926 (±0.065). The WG showed a DS, HD and VS of 0.738 (±0.144), 36.2 (±35.6 vx) and 0.853 (±0.143), respectively. The TZ showed generally lower variability with a DS of 0.738 (±0.144), HD of 24.8 (±16 vx) and VS of 0.908 (±0.126). The lowest variability was found for the SV with DS of 0.884 (±0.0407), HD of 17 (±10.9 vx) and VS of 0.936 (±0.0509). We found a markedly lower DS of the segmentations in the apex (0.85 ± 0.12) compared to the base (0.87 ± 0.10, p Conclusions We report baseline values for interreader variability of prostate and SV segmentation on T2w MRI. Variability was highest in the apex, lower in the base, and lowest in the midgland.