Deep learning model for the detection of prostate cancer and classification of clinically significant disease using multiparametric MRI in comparison to PI-RADs score.

BACKGROUND: The Prostate Imaging Reporting and Data System (PI-RADS) is an established reporting scheme for multiparametric magnetic resonance imaging (mpMRI) to distinguish clinically significant prostate cancer (csPCa). Deep learning (DL) holds great potential for automating csPCa classification on mpMRI. METHOD: To compare the performance between a DL algorithm and PI-RADS categorization in PCa detection and csPCa classification, we included 1,729 consecutive patients who underwent radical prostatectomy or biopsy in Tongji hospital. We developed DL models by integrating individual mpMRI sequences and employing an ensemble approach for distinguishing between csPCa and CiSPCa (specifically defined as PCa with a Gleason group 1 or benign prostate disease, training cohort: 1,285 patients vs. external testing cohort: 315 patients). RESULTS: DL-based models exhibited higher csPCa detection rates than PI-RADS categorization (area under the curve [AUC]: 0.902; sensitivity: 0.728; specificity: 0.906 vs. AUC: 0.759; sensitivity: 0.761; specificity: 0.756) (P < 0.001) Notably, DL networks exhibited significant strength in the prostate-specific antigen (PSA) arm < 10 ng/ml compared with PI-RADS assessment (AUC: 0.788; sensitivity: 0.588; specificity: 0.883 vs. AUC: 0.618; sensitivity: 0.379; specificity: 0.763) (P = 0.041). CONCLUSIONS: We developed DL-based mpMRI ensemble models for csPCa classification with improved sensitivity, specificity, and accuracy compared with clinical PI-RADS assessment. In the PSA-stratified condition, the DL ensemble model performed better than PI-RADS in the detection of csPCa in both the high PSA group and the low PSA group.

A Randomized Comparison of Transradial and Transfemoral Approach in Hepatic Arterial Infusion Chemotherapy.

INTRODUCTION: Hepatic arterial infusion chemotherapy (HAIC) has been popular for treating unresectable hepatocellular carcinoma (HCC). However, there are few reports comparing the transradial approach (TRA) and transfemoral approach (TFA) in HAIC. OBJECTIVE: This study aimed to compare the duration of the hepatic artery catheterization, fluoroscopy time (FT), radiation exposure, safety, and quality of life associated with the procedure in patients undergoing HAIC via TRA and TFA. METHODS: This prospective, single-center, randomized, controlled study included 120 patients with unresectable HCC undergoing HAIC procedures. Patients were randomly assigned to group A (n = 60, TRA-HAIC) or group B (n = 60, TFA-HAIC). The hepatic artery catheterization time, FT, entrance surface dose (ESD), dose area product (DAP), procedure-related complications, and quality of life associated with the procedure were assessed between the two groups. Independent-sample t-test and analysis of variance (ANOVA) were used to assess differences. Statistical significance was set at P < 0.05. RESULTS: HAIC procedures were successfully performed in both groups. The hepatic artery catheterization time (19.35 ± 5.84 vs. 18.93 ± 5.62 minutes, P = 0.837), FT (2.35 ± 2.23 vs. 2.25 ± 2.16 minutes, P = 0.901), ESD (259.32 ± 167.46 vs. 250.56 ± 170.58 mGy, P = 0.449), and DAP (125.37 ± 60.65 vs. 120.56 ± 64.33 Gy.cm3, P = 0.566) were comparable between the two groups. The incidence of artery occlusion (10.0% vs. 0%, P < 0.001) in the TRA group was significantly higher than that in the TFA group. TRA was associated with a statistically significant (P < 0.05) improvement in the quality of life. CONCLUSION: TRA to HAIC was associated with greater improvement in the quality of life associated with the procedure compared with TFA. Both approaches to HAIC had similar efficiency, safety, radiation exposure, and procedure duration.

Recent Progress in Advanced Hydrogel-Based Embolic Agents: From Rational Design Strategies to Improved Endovascular Embolization.

Transcatheter arterial embolization, a minimally invasive treatment to deliberately occlude the blood vessels, has become a safe and effective procedure for the management of vascular diseases and benign/malignant tumors. Particularly, hydrogel-based embolic agents have garnered much attention because of their potential to address some of the limitations of clinically used embolic agents and can be rationally designed to impart more favorable characteristics or functions. In this review, the recent progress toward the development of polymer-based hydrogels for effective endovascular embolization, including the in situ gelling hydrogels mediated by physically or chemically crosslinking, imageable hydrogels for intraprocedural and postprocedural feedback, use of hydrogels as the drug depot for local delivery of therapeutic drugs, hemostatic hydrogels inducing extrinsic or intrinsic coagulation of blood, stimuli-responsive shape memory hydrogels as the smart embolization devices, and hydrogels incorporating external-stimuli functional materials for multidisciplinary therapy, is systemically summarized. Moreover, the potential considerations of hydrogel-based embolic agents confronted in therapeutic embolization are pointed out. Finally, the perspectives for the development of more effective embolic hydrogels are also highlighted.

Apparent Diffusion Coefficient as a Noninvasive Biomarker for the Early Response in Hepatocellular Carcinoma After Transcatheter Arterial Chemoembolization Using Drug-eluting Beads.

BACKGROUND: Prognostic evaluation for Hepatocellular Carcinoma (HCC) after Transcatheter Arterial Chemoembolization (TACE) using Drug-Eluting Beads (DEBs) is essential for guiding the personalized treatment and follow-up strategy. Apparent Diffusion Coefficient (ADC) has been reported as a biomarker in conventional TACE. OBJECTIVE: This study aimed to evaluate the diagnostic value of ADCbaseline, ADC change, and ADCratio in predicting the early objective response for HCC after DEB-TACE. METHODS: This prospective single-center study included 32 consecutive patients undergoing dynamic contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging before and 1 month after DEB-TACE. After DEB-TACE, patients were grouped based on the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria into responders (complete response [CR], partial response [PR]) and nonresponders (stable disease [SD], progressive disease [PD]). The Mann- Whitney U test and receiver operating characteristic (ROC) curves were performed to assess the statistical differences in ADCbaseline, ADC change, and ADCratio between responders and nonresponders. RESULTS: At post-DEB-TACE follow-up MRI, 62.5% (n = 20, 11 CRs, and 9 PRs) of patients showed objective response, and 37.5% (n = 12, 7 SDs, and 5 PDs) did not respond to chemoembolization. Nonresponders had a significantly higher ADCbaseline value than responders (p < 0.001). The ROC for identifying the response to chemoembolization demonstrated that the threshold ADCbaseline value of 0.920 × 10-3 mm2/s had 100% sensitivity and 70% specificity. The ADC change and ADCratio of responders were higher than that of nonresponders (p < 0.001). CONCLUSION: ADCbaseline, ADC change, and ADCratio may be utilized as a noninvasive biomarker for predicting the early response of HCC to DEB-TACE.

Multi-parameter diffusion and perfusion magnetic resonance imaging and radiomics nomogram for preoperative evaluation of aquaporin-1 expression in rectal cancer.

PURPOSE: The overexpression of aquaporin-1 (AQP1) is associated with poor prognosis in rectal cancer. This study aimed to explore the value of multi-parameter diffusion and perfusion MRI and radiomics models in predicting AQP1 high expression. METHODS: This prospective study was performed from July 2019 to February 2021, which included rectal cancer participants after preoperative rectal MRI, with diffusion-weighted imaging, intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI), and dynamic contrast-enhanced (DCE) sequences. Radiomic features were extracted from MR images, and immunohistochemical tests assessed AQP1 expression. Selected quantitative MRI and radiomic features were analyzed. Receiver operating characteristic (ROC) curves evaluated the predictive performance. The nomogram performance was evaluated by its calibration, discrimen, and clinical utility. The intraclass correlation coefficient evaluated the interobserver agreement for the MRI features. RESULTS: 110 participants with the age of 60.7 ± 12.5 years been enrolled in this study. The apparent diffusion coefficient (ADC), IVIM_D, DKI_diffusivity, and DCE_Ktrans were significantly higher in participants with high AQP1 expression than in those with low expression (P < 0.05). ADC (b = 1000, 2000, and 3000 s/mm2), IVIM_D, DKI_diffusivity, and DCE_Ktrans were positively correlated (r = 0.205, 0.275, 0.37, 0.235, 0.229, and 0.227, respectively; P < 0.05), whereas DKI_Kurtosis was negatively correlated (r = - 0.22, P = 0.021) with AQP1 expression. ADC (b = 3000 s/mm2), IVIM_D, DKI_ diffusivity, DKI_Kurtosis, and DCE_Ktrans had moderate diagnostic efficiencies for high AQP1 expression (AUC = 0.715, 0.636, 0.627, 0.633, and 0.632, respectively; P < 0.05). The radiomic features had excellent predictive efficiency for high AQP1 expression (AUC = 0.967 and 0.917 for training and validation). The model-based nomogram had C-indexes of 0.932 and 0.851 for the training and validation cohorts, which indicated good fitting to the calibration curves (p > 0.05). CONCLUSION: Diffusion and perfusion MRI can indicate the aquaporin-1 expression in rectal cancer, and radiomic features can enhance the predictive efficiency for high AQP1 expression. A nomogram for high aquaporin-1 expression will improve clinical decision-making.

Efficacy, safety, and prognostic factors of drug-eluting beads transarterial chemoembolization using CalliSpheres in treating huge hepatocellular carcinoma patients.

BACKGROUND: The treatment of huge hepatocellular carcinoma (HCC) is still challengeable due to its deteriorative heterogeneity, for which conventional transarterial chemoembolization (TACE) is proposed as an efficient therapy; however, drug-eluting beads TACE (DEB-TACE) is rarely reported in these patients. Thus, the current study aimed to explore the efficacy, prognostic factors, and safety of DEB-TACE using CalliSpheres in huge HCC patients. METHODS: Ninety-nine huge HCC patients treated by DEB-TACE using CalliSpheres were retrospectively reviewed. Treatment response, change of tumor markers, liver function indexes, progression-free survival (PFS), and adverse events were retrieved. RESULTS: Objective response rate (ORR) was 66.1%, 48.6%, and 23.8%, then disease control rate (DCR) was 85.5%, 67.6%, and 33.3% at month (M) 1, M3, and M6, respectively; furthermore, carcinoembryonic antigen (CEA) (p = 0.037), alpha fetoprotein (AFP) (p < 0.001), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) (p < 0.001) were all declined at 1 month after DEB-TACE. The median PFS was 8.3 (95% confidence interval: 6.0-10.6) months with 1-year and 2-year PFS rates of 38.5% and 15.5%, accordingly. Moreover, elevated China liver cancer (CNLC) stage (p = 0.036, hazard ratio (HR): 1.937) and abnormal cancer antigen 199 (p = 0.019, HR: 2.465) were correlated with unfavorable PFS. Besides, liver function indexes were not deteriorated after DEB-TACE. Lastly, main adverse events included pain (20.2%), fever (17.2%), nausea (14.1%), and vomit (9.1%), which were mild and manageable. CONCLUSION: DEB-TACE using CalliSpheres presents satisfying efficacy and tolerable safety in huge HCC patients, suggesting that it might be a good treatment option for these patients.

Value of Intra-Perinodular Textural Transition Features from MRI in Distinguishing Between Benign and Malignant Testicular Lesions.

PURPOSE: To compare the performance of histogram analysis and intra-perinodular textural transition (Ipris) for distinguishing between benign and malignant testicular lesions. PATIENTS AND METHODS: This retrospective study included 76 patients with 80 pathologically confirmed testicular lesions (55 malignant, 25 benign). All patients underwent preoperative T2-weighted imaging (T2WI) on a 3.0T MR scanner. All testicular lesions were manually segmented on axial T2WI, and histogram and Ipris features were extracted. Thirty enrolled patients were randomly selected to estimate the robustness of the features. We used intraclass correlation coefficients (ICCs) to evaluate intra- and interobserver agreement of features, independent t-test or Mann-Whitney U-test to compare features between benign and malignant lesions, and receiver operating characteristic curve analysis to evaluate the diagnostic performance of features. RESULTS: Eighteen histogram features and forty-eight Ipris features were extracted from T2WI of each lesion. Most (60/66) histogram and Ipris features had good robustness (ICC of both intra- and interobserver variabilities >0.6). Three histogram and nine Ipris features were significantly different between the benign and malignant groups. The area under the curve values for Energy, TotalEnergy, and Ipris_shell1_id_std were 0.807, 0.808, and 0.708, respectively, which were relatively higher than those of other features. CONCLUSION: Ipris features may be useful for identifying benign and malignant testicular tumors but have no significant advantage over conventional histogram features.

Oxygen-Challenge Blood Oxygen Level-Dependent Magnetic Resonance Imaging for Evaluation of Early Change of Hepatocellular Carcinoma to Chemoembolization: A Feasibility Study.

RATIONALE AND OBJECTIVES: To investigate the feasibility of oxygen-challenge blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) at 3T for evaluating the early change of blood oxygenation before and after transcatheter arterial embolization (TACE) in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Thirty HCC patients with cirrhosis (HCC group, n = 30) and 30 healthy volunteers (control group, n = 30) were included in this study. Patients in the HCC group underwent BOLD before and 1 month after TACE. Oxygen was administered via a mask. Differences between pre- and post-O2 T2* values were evaluated using a pairwise t-test. Analysis of variance was performed to assess the statistical differences in the T2* values measured in HCC group pre-TACE and post-TACE and in healthy volunteers. RESULTS: In the HCC group, the pre- and post-O2 T2* values of the cancerous area before TACE were 26.03 ± 3.30 and 26.84 ± 3.42 msec, respectively, and both decreased significantly to 8.67 ± 1.76 and 8.82 ± 1.80 msec, respectively, at 1 month after TACE (p < 0.001). The respective pre- and post-O2 T2* values of the noncancerous area increased significantly from 14.96 ± 2.32 and 15.33 ± 2.28 msec at baseline to 16.38 ± 2.22 and 16.89 ± 2.24 msec at 1 month after TACE (p < 0.001). No significant response to BOLD was observed in the control group (p = 0.059). CONCLUSION: Oxygen-challenge BOLD MRI is feasible to assess post-TACE changes in HCC patients.

Water-stable and finasteride-loaded polyvinyl alcohol nanofibrous particles with sustained drug release for improved prostatic artery embolization - In vitro and in vivo evaluation.

Prostatic artery embolization (PAE) has been a well-established treatment for benign prostatic hyperplasia (BPH). To enhance the therapeutic efficacy, a strategy is to use embolic agent preloaded with 5α-reductase inhibitors for localized drug delivery. In this study, finasteride (FNS) was encapsulated into the polyvinyl alcohol (PVA) nanofibers via co-electrospinning technique, followed by heat treatment and cryogenic grinding to convert them into nanofibrous particles as a drug-loaded embolic agent. The FNS was found to be distributed uniformly in PVA nanofibers, and the processed FNS/PVA nanofibrous particles were 272 µm in mean particle size. Besides, the studies on the composition, thermal properties, swelling ratio, and water stability of the nanofibers and drug showed that the FNS remained its crystalline state in PVA nanofibers. The heat treatment increased the crystallinity of nanofibers and rendered them water stability. Both FNS and PVA possessed excellent thermal stability at high temperature (150 °C). In addition, in vitro drug release studies suggested the FNS followed a favorable sustained release up to 744 h. Furthermore, the cell viability and hemocompatibility assays indicated the nanofibers possessed excellent cytocompatibility and with no evidence of hemolysis. More importantly, the in vivo PAE procedures on beagles demonstrated the crosslinked FNS/PVA nanofibrous particles exhibited higher embolization efficacy with more obvious prostate volume (PV) reduction compared to crosslinked PVA nanofibrous particles after embolization for 1, 3, and 6 months (P < 0.05). Therefore, such drug-loaded PVA nanofibrous particles combined physical embolization and localized medical therapy together, which offer great potential to be used as an effective embolic agent for BPH therapy.

Discrimination between benign and malignant testicular lesions using volumetric apparent diffusion coefficient histogram analysis.

PURPOSE: This study aimed to evaluate the role of volumetric apparent diffusion coefficient (ADC) histogram analysis in discriminating between benign and malignant testicular masses. METHODS: In this retrospective study, fifty-nine patients with 61 pathologically confirmed testicular masses were consecutively enrolled, including 18 benign lesions and 43 malignant lesions. All patients conducted preoperative magnetic resonance imaging (MRI) with diffusion-weighted imaging. Eighteen volumetric histogram parameters were extracted from the ADC map of each lesion. Comparisons were conducted by an independent t-test or Mann-Whitney U test, where appropriate. The classification performance of the parameters that showed significant differences between benign and malignant testicular disease were evaluated via receiver operating characteristic (ROC) curve analysis. RESULTS: Among the 18 histogram parameters we extracted, the energy, total energy, and range of ADC of testicular malignancies were all significantly increased compared with those of benignities. The minimum ADC and 10th percentile ADC of testicular malignancies were both significantly reduced compared with those of benignities. The minimum ADC value achieved the highest diagnostic performance in distinguishing between testicular benignities and malignancies, with an area under the ROC curve (AUC) of 0.822, sensitivity of 81.40 %, and specificity of 77.78 %. CONCLUSIONS: Volumetric ADC histogram analysis might be a useful tool to preoperatively discriminate between benign and malignant testicular masses.

Engineered Cell-Derived Microparticles Bi2Se3/DOX@MPs for Imaging Guided Synergistic Photothermal/Low-Dose Chemotherapy of Cancer.

Cell-derived microparticles, which are recognized as nanosized phospholipid bilayer membrane vesicles, have exhibited great potential to serve as drug delivery systems in cancer therapy. However, for the purpose of comprehensive therapy, microparticles decorated with multiple therapeutic components are needed, but effective engineering strategies are limited and still remain enormous challenges. Herein, Bi2Se3 nanodots and doxorubicin hydrochloride (DOX) co-embedded tumor cell-derived microparticles (Bi2Se3/DOX@MPs) are successfully constructed through ultraviolet light irradiation-induced budding of parent cells which are preloaded with Bi2Se3 nanodots and DOX via electroporation. The multifunctional microparticles are obtained with high controllability and drug-loading capacity without unfavorable membrane surface destruction, maintaining their excellent intrinsic biological behaviors. Through membrane fusion cellular internalization, Bi2Se3/DOX@MPs show enhanced cellular internalization and deepened tumor penetration, resulting in extreme cell damage in vitro without considering endosomal escape. Because of their distinguished photothermal performance and tumor homing target capability, Bi2Se3/DOX@MPs exhibit admirable dual-modal imaging capacity and outstanding tumor suppression effect. Under 808 nm laser irradiation, intravenous injection of Bi2Se3/DOX@MPs into H22 tumor-bearing mice results in remarkably synergistic antitumor efficacy by combining photothermal therapy with low-dose chemotherapy in vivo. Furthermore, the negligible hemolytic activity, considerable metabolizability, and low systemic toxicity of Bi2Se3/DOX@MPs imply their distinguished biocompatibility and great potential for tumor theranostics.

Prediction of Pathological Upgrading at Radical Prostatectomy in Prostate Cancer Eligible for Active Surveillance: A Texture Features and Machine Learning-Based Analysis of Apparent Diffusion Coefficient Maps.

OBJECTIVE: To evaluate a combination of texture features and machine learning-based analysis of apparent diffusion coefficient (ADC) maps for the prediction of Grade Group (GG) upgrading in Gleason score (GS) ≤6 prostate cancer (PCa) (GG1) and GS 3 + 4 PCa (GG2). MATERIALS AND METHODS: Fifty-nine patients who were biopsy-proven to have GG1 or GG2 and underwent MRI examination with the same MRI scanner prior to transrectal ultrasound (TRUS)-guided systemic biopsy were included. All these patients received radical prostatectomy to confirm the final GG. Patients were divided into training cohort and test cohort. 94 texture features were extracted from ADC maps for each patient. The independent sample t-test or Mann-Whitney U test was used to identify the texture features with statistically significant differences between GG upgrading group and GG non-upgrading group. Texture features of GG1 and GG2 were compared based on the final pathology of radical prostatectomy. We used the least absolute shrinkage and selection operator (LASSO) algorithm to filter features. Four supervised machine learning methods were employed. The prediction performance of each model was evaluated by area under the receiver operating characteristic curve (AUC). The statistical comparison between AUCs was performed. RESULTS: Six texture features were selected for the machine learning models building. These texture features were significantly different between GG upgrading group and GG non-upgrading group (P < 0.05). The six features had no significant difference between GG1 and GG2 based on the final pathology of radical prostatectomy. All machine learning methods had satisfactory predictive efficacy. The diagnostic performance of nearest neighbor algorithm (NNA) and support vector machine (SVM) was better than random forests (RF) in the training cohort. The AUC, sensitivity, and specificity of NNA were 0.872 (95% CI: 0.750-0.994), 0.967, and 0.778, respectively. The AUC, sensitivity, and specificity of SVM were 0.861 (95%CI: 0.732-0.991), 1.000, and 0.722, respectively. There had no significant difference between AUCs in the test cohort. CONCLUSION: A combination of texture features and machine learning-based analysis of ADC maps could predict PCa GG upgrading from biopsy to radical prostatectomy non-invasively with satisfactory predictive efficacy.

Diagnostic Performance and Interobserver Consistency of the Prostate Imaging Reporting and Data System Version 2: A Study on Six Prostate Radiologists with Different Experiences from Half a Year to 17 Years.

BACKGROUND: One of the main aims of the updated Prostate Imaging Reporting and Data System Version 2 (PI-RADS v2) is to diminish variation in the interpretation and reporting of prostate imaging, especially among readers with varied experience levels. This study aimed to retrospectively analyze diagnostic consistency and accuracy for prostate disease among six radiologists with different experience levels from a single center and to evaluate the diagnostic performance of PI-RADS v2 scores in the detection of clinically significant prostate cancer (PCa). METHODS: From December 2014 to March 2016, 84 PCa patients and 99 benign prostatic shyperplasia patients who underwent 3.0T multiparametric magnetic resonance imaging before biopsy were included in our study. All patients received evaluation according to the PI-RADS v2 scale (1-5 scores) from six blinded readers (with 6 months and 2, 3, 4, 5, or 17 years of experience, respectively, the last reader was a reviewer/contributor for the PI-RADS v2). The correlation among the readers' scores and the Gleason score (GS) was determined with the Kendall test. Intra-/inter-observer agreement was evaluated using κ statistics, while receiver operating characteristic curve and area under the curve analyses were performed to evaluate the diagnostic performance of the scores. RESULTS: Based on the PI-RADS v2, the median κ score and standard error among all possible pairs of readers were 0.506 and 0.043, respectively; the average correlation between the six readers' scores and the GS was positive, exhibiting weak-to-moderate strength (r = 0.391, P = 0.006). The AUC values of the six radiologists were 0.883, 0.924, 0.927, 0.932, 0.929, and 0.947, respectively. CONCLUSION: The inter-reader agreement for the PI-RADS v2 among the six readers with different experience is weak to moderate. Different experience levels affect the interpretation of MRI images.

Characterization of testicular germ cell tumors: Whole-lesion histogram analysis of the apparent diffusion coefficient at 3T.

PURPOSE: To assess the values of parameters derived from whole-lesion histograms of the apparent diffusion coefficient (ADC) at 3T for the characterization of testicular germ cell tumors (TGCTs). MATERIALS AND METHODS: A total of 24 men with TGCTs underwent 3T diffusion-weighted imaging. Fourteen tumors were pathologically confirmed as seminomas, and ten tumors were pathologically confirmed as nonseminomas. Whole-lesion histogram analysis of the ADC values was performed. A Mann-Whitney U test was employed to compare the differences in ADC histogram parameters between seminomas and nonseminomas. Receiver operating characteristic analysis was used to identify the cutoff values for each parameter for differentiating seminomas from nonseminomas; furthermore, the area under the curve (AUC) was calculated to evaluate the diagnostic accuracy. RESULTS: The median of 10th, 25th, 50th, 75th, and 90th percentiles and mean, minimum and maximum ADC values were all significantly reduced for seminomas compared with nonseminomas (p<0.05 for all). In contrast, the median of kurtosis and skewness of ADC values of seminomas were both significantly increased compared with those of nonseminomas (p=0.003 and 0.001, respectively). For differentiating nonseminomas from seminomas, the 10th percentile ADC yielded the highest AUC with a sensitivity and specificity of 100% and 92.86%, respectively. CONCLUSION: Whole-lesion histogram analysis of ADCs might be used for preoperative characterization of TGCTs.

Evaluation of different mathematical models and different b-value ranges of diffusion-weighted imaging in peripheral zone prostate cancer detection using b-value up to 4500 s/mm2.

OBJECTIVES: To evaluate the diagnostic performance of different mathematical models and different b-value ranges of diffusion-weighted imaging (DWI) in peripheral zone prostate cancer (PZ PCa) detection. METHODS: Fifty-six patients with histologically proven PZ PCa who underwent DWI-magnetic resonance imaging (MRI) using 21 b-values (0-4500 s/mm2) were included. The mean signal intensities of the regions of interest (ROIs) placed in benign PZs and cancerous tissues on DWI images were fitted using mono-exponential, bi-exponential, stretched-exponential, and kurtosis models. The b-values were divided into four ranges: 0-1000, 0-2000, 0-3200, and 0-4500 s/mm2, grouped as A, B, C, and D, respectively. ADC, , D*, f, DDC, α, Dapp, and Kapp were estimated for each group. The adjusted coefficient of determination (R2) was calculated to measure goodness-of-fit. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of the parameters. RESULTS: All parameters except D* showed significant differences between cancerous tissues and benign PZs in each group. The area under the curve values (AUCs) of ADC were comparable in groups C and D (p = 0.980) and were significantly higher than those in groups A and B (p< 0.05 for all). The AUCs of ADC and Kapp in groups B and C were similar (p = 0.07 and p = 0.954), and were significantly higher than the other parameters (p< 0.001 for all). The AUCs of ADC in group D was slightly higher than Kapp (p = 0.002), and both were significantly higher than the other parameters (p< 0.001 for all). CONCLUSIONS: ADC derived from conventional mono-exponential high b-value (3200 s/mm2) models is an optimal parameter for PZ PCa detection.

Benign prostatic hyperplasia after prostatic arterial embolization in a canine model: A 3T multiparametric MRI and whole-mount step-section pathology correlated longitudinal study.

PURPOSE: To explore the morphological and functional characteristics of prostatic arterial embolization (PAE) in a canine model of benign prostatic hyperplasia (BPH) with 3T multiparametric magnetic resonance imaging (mp-MRI) and whole-mount step-section pathology correlation. MATERIALS AND METHODS: Eight adult male beagle dogs with hormone-induced BPH underwent 3T mp-MRI before and 1, 3, and 6 months after PAE, with subsequent whole-mount step-section pathologic assessment. Images were acquired using T1 -weighted images (T1 WI), T2 WI, 3D-SPACE, diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), T2 -mapping, and dynamic contrast-enhanced (DCE) sequences. Variance analysis was performed to assess statistical differences in prostatic volume (PV), apparent diffusion coefficient (ADC), and T2 values. Pearson correlation analysis was performed to correlate ADC, T2 , and PV. RESULTS: The PV decreased from baseline to 1, 3, and 6 months after PAE from (25.88 ± 7.09) cm3 to (6.48 ± 2.08) cm3 , (6.48 ± 3.39) cm3 , (6.20 ± 2.88) cm3 . The ADC values sequentially decreased from baseline to 1, 3, and 6 months after PAE from (1497.06 ± 222.72) × 10-6 mm2 /s to (1056.00 ± 189.46) × 10-6 mm2 /s, (950.48 ± 77.85) × 10-6 mm2 /s, (980.98 ± 107.78) × 10-6 mm2 /s. The T2 values decreased from baseline to 1, 3, and 6 months after PAE were (83.74 ± 5.29) msec, (68.72 ± 5.66) msec, (53.96 ± 15.04) msec, (49.81 ± 13.34) msec, respectively. ADC and T2 values were positively correlated with PV (r = 0.823 and 0.744, respectively). Microhemorrhages and hemosiderin were found on SWI after PAE. CONCLUSION: 3T mp-MRI may facilitate noninvasive assessment of morphological and functional changes of BPH after PAE. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1220-1229.