Peripheral Zone Research Articles

Lexico-Semantic Macrofield “Homeland” in Modern Russian (On the Material of the National Corpus of the Russian Language)

The lexical-semantic macrofield homeland is based on semantic origins, which are the components of the dictionary definitions. The lexeme homeland is a polysemy, which indicates its wide semantic range and productive use. The boundaries of the lexical-semantic macro-field under study are conditional and united on the basis of semantic combinations of the terms “fatherland”, “country”, “birthplace”, “origin”, “birth / origin” (of someone or something). Lexical units of the field “homeland” are distributed on the principle “core – periphery”: lexical-semantic groups with synonymic and antonymic series organize core (subject lexical-grammatical groups), near-core (procedural lexical-grammatical groups) and peripheral (attribute lexical-grammatical groups) zones of lexical-semantic field. Syntagmatic relations between lexical units of the lexical-semantic macrofield “homeland” are built according to three basic models (“adjective name + homeland”, “homeland + noun in the genitive case”, “verb + homeland”) and are distributed in thematic groups.

Experiments into the interaction of side dilution jets with bluff-body stabilised annular jets

Fundamental insights into the effects of side dilution jets on the flow behaviour and turbulence field in gas turbine combustors further advances the ability to use these jets to control (upstream) flame stability and (downstream) emissions. Despite this, the interaction of side dilution jets with typical flame anchoring mechanisms, such as bluff-bodies, and annular flows, both swirling and non-swirling, remains elusive due to the challenges of undertaking highly resolved laser diagnostics in such complex geometries. In this work, Particle Image Velocimetry (PIV) is used to investigate the interaction of turbulent side dilution jets (Red = 18,000 and 11,300) with bluff-body stabilised annular jets (Res = 35500 and 17800), under both swirling (S = 0.3) and non-swirling (S = 0) conditions. Boundary conditions for the cases studied are well-defined through Constant Temperature Anemometry, which in conjunction with the PIV resolved flow field means the results presented additionally serve as good benchmark cases for modelling (not undertaken here). The experiments are conducted in an optically accessible 700 mm long square-like (310 mm × 310 mm) enclosure equipped with four peripheral side dilution jets on the rounded corner supports.Results show that irrespective of the flow configuration used (swirling or non-swirling), side dilution jets considerably modify the overall flow field and lead to the development of characteristic recirculation zones on the periphery of the annular jet, named as Peripheral Recirculation Zones (PRZ). In the upstream region, PRZ significantly promote turbulence in the outer shear layer of the bluff-body stabilised annular jet, leading to a massive 176% (at x/D = 1.4) and 218% (x/D = 1.8) increase in peak turbulent kinetic energy. These high levels of turbulence further magnify closer to the location of the side jets. In the downstream (beyond x/D > 2) of the bluff-body stabilised annular jet, noticeable increases in centreline velocity decay (13%) and jet spreading (32%) are observed in the presence of a PRZ, which indicates better mixing and flow entrainment. The overall effects of side dilution jets vary directly and inversely with the Reynolds number of side dilution jets and annular jets, respectively. To resolve the flow dynamic behaviour independent of heat release, all tests are undertaken isothermally (non-reacting).

On Liquid Flow Maldistribution through Investigation of Random Open-Structure Packings

The optimal design of packed columns for separation processes is strongly dependent on an accurate prediction of the fluid flows in the packing. Insufficient knowledge about the complex factors and mechanisms governing hydrodynamic effects is compensated for by empirical information. The present study fills the gap in experimental data about the liquid phase distribution in plastic Raschig Super-Ring (RSRP) packing and plastic Ralu–Flow (RF) packing. These belong to the family of widely used random packings with an open lattice structure characterized by high mass transfer efficiency and a low pressure drop. The study was performed using the liquid collection method with a device with concentric annular collection sections at the packing outlet. Large-scale liquid maldistribution in the central and peripheral zones of the packed bed were evaluated in comparison data on competing random and structured packings. The effects of the packing size and the liquid load on the radial distribution of the superficial liquid velocity, wall flow formation and the maldistribution factor were investigated and analyzed. The results contribute to deepening the knowledge about the phenomenon of large-scale liquid flow maldistribution in packed columns, as well as to design enhancement.

Atoll sign ieventail diagnostic

The atoll sign or inverted halot sign is seen on high-resolution chest CT scans as a central frosted glass area surrounded by peripheral condensation in a ring or crescent, the contours of which may be smooth or spiculated [1]. Histologically, the central zone (ground glass opacity) corresponds to alveolar septal inflammation and cellular debris in the alveolar spaces, while the condensed peripheral zone corresponds to granulomatous tissue in the distal air spaces [2]

Using Land Use and Transportation Interaction (LUTI) models to determine land use effects from new vehicle transportation technologies; a regional scale of analysis

Advances in automotive engineering have brought about a range of new vehicle technologies, such as automation, connectivity and electrification, which are expected to have multiple effects on different aspects of people's lives and have the potential of radically transforming the transportation status quo. This paper explores the effects that such new technologies can have on land use by employing a Land Use and Transportation Interaction (LUTI) modelling approach. A new methodology is developed to simulate the effects of automation, connectivity and electrification on accessibility and to conduct a sensitivity analysis. The analysis is carried out on a regional scale to determine the effects of the new technologies on multiple cities that form a region. The case study for this application is the region of the West Midlands (UK). The results suggest that new vehicle technologies can affect accessibility, population and employment in the cities of the region, the region itself, as well as the peripheral zones beyond the boundary of the region in a 15-year modelling period. Most notably, the two main urban cores of the region are found to not lose their financial power, despite increases in employment opportunities and population density in more rural outskirts. The increased accessibility also results in the relocation of lower-income households to places with lower housing rent. The sensitivity analysis shows that these findings are mostly impacted by changes in road capacity (which is expected to be generally higher as a result of these new technologies), as well as different penetration levels in the fleet.

Characterization and chemical fractionation of potentially toxic elements in soils of a pre-mining mineralized area; an evaluation of mobility and environmental risk.

The environmental geochemical characterization of mineralized areas prior to mining does not receive adequate attention. This study shows trace element distribution in soils of two unexploited porphyry copper deposits located in Darreh-Zereshk and Ali-Abad in central Iran. The study was carried out using a compositional data analysis (CoDa) approach and combination of multivariate statistics and clustering techniques, which made it possible to identify the geochemical associations representing the different areas of the mineral deposits. The results of the chemical analyses, performed by ICP-MS, revealed high concentrations of those elements typically associated with porphyry deposits (As, Co, Cu, Mo, Ni, Pb, and Zn). The typical zonal pattern with an anomaly of Cu in central parts of the system and the prevalence of epithermal elements (Ag, Cd, Pb, and Zn) toward the peripheral propylitic alteration zone were recognized. The XRD analysis of selected soil samples allowed us to determine the distribution of elements within the different carrier minerals. Afterward, geochemical speciation patterns were investigated by a four-step sequential extraction procedure based on BCR protocol. The residual fraction consisting of primary resistant minerals was found to be the main host for As (73-93.4%), Cr (65.1-79.6%), Cu (54.3-81.4%), Ni (58.9-80.6%), V (75.9-88%), and Zn (56.5-60.5%) in the studied soils. Even though these elements are not readily leachable, their behavior and distribution could be largely affected by the mining operation and consequent changes in the physicochemical properties of the soil. The soluble-exchangeable phase was only less than 15% of the total extractions for all elements, except for Cd. With respect to the mobility factor (MF), Cd was the most mobile element followed by Sb and Pb. The measured risk assessment code (RAC) presented the following risk order: Cd > Sb > Ni > Co > Pb > Cr > As > Zn > Cu > V. This study reveals that the acquisition of pre-mining geo-environmental data of trace elements is very important to establish pre-mining backgrounds and baselines for evaluating post-mining or post-reclamation geochemical signatures.

Die multiparametrische MRT der Prostata: Anforderungen und Grundlagen der Befundung

Multiparametric MRI (mpMRI) is one of the primary diagnostic tools for detecting clinically relevant prostate cancer. It should be routinely used in addition to urological investigations owing to its higher diagnostic yield than systematic biopsies. However, combining targeted and systematic biopsies achieves the highest diagnostic rate. The Prostate Imaging Reporting and Data System (PI-RADS Version2.1) standardizes the acquisition and interpretation of mpMRI of the prostate. It consists of high-resolution T2- and diffusion-weighted images, the corresponding apparent diffusion coefficient (ADC) maps, and adynamic contrast-enhanced sequence. Reports describe the increasing likelihood of clinically significant prostate cancer with PI-RADS categories 1-5. The MRI sequence determining the PI-RADS category of alesion depends on its location within the prostate: in the transitional zone, the T2-weighted sequence and, in the peripheral zone, the diffusion-weighted sequence are the primary determinants. The diffusion-weighted and contrast-enhanced sequences provide secondary classification for the transitional and peripheral zones, respectively. This review summarizes and illustrates the diagnostic criteria defined in PI-RADS 2.1. In addition, evidence for mpMRI of the prostate, its indication and implementation are described.

Characterization of high-grade prostate cancer at multiparametric MRI: assessment of PI-RADS version 2.1 and version 2 descriptors across 21 readers with varying experience (MULTI study)

ObjectiveTo assess PI-RADSv2.1 and PI-RADSv2 descriptors across readers with varying experience.MethodsTwenty-one radiologists (7 experienced (≥ 5 years) seniors, 7 less experienced seniors and 7 juniors) assessed 240 ‘predefined’ lesions from 159 pre-biopsy multiparametric prostate MRIs. They specified their location (peripheral, transition or central zone) and size, and scored them using PI-RADSv2.1 and PI-RADSv2 descriptors. They also described and scored ‘additional’ lesions if needed. Per-lesion analysis assessed the ‘predefined’ lesions, using targeted biopsy as reference; per-lobe analysis included ‘predefined’ and ‘additional’ lesions, using combined systematic and targeted biopsy as reference. Areas under the curve (AUCs) quantified the performance in diagnosing clinically significant cancer (csPCa; ISUP ≥ 2 cancer). Kappa coefficients (κ) or concordance correlation coefficients (CCC) assessed inter-reader agreement.ResultsAt per-lesion analysis, inter-reader agreement on location and size was moderate-to-good (κ = 0.60–0.73) and excellent (CCC ≥ 0.80), respectively. Agreement on PI-RADSv2.1 scoring was moderate (κ = 0.43–0.47) for seniors and fair (κ = 0.39) for juniors. Using PI-RADSv2.1, juniors obtained a significantly lower AUC (0.74; 95% confidence interval [95%CI]: 0.70–0.79) than experienced seniors (0.80; 95%CI 0.76–0.84; p = 0.008) but not than less experienced seniors (0.74; 95%CI 0.70–0.78; p = 0.75). As compared to PI-RADSv2, PI-RADSv2.1 downgraded 17 lesions/reader (interquartile range [IQR]: 6–29), of which 2 (IQR: 1–3) were csPCa; it upgraded 4 lesions/reader (IQR: 2–7), of which 1 (IQR: 0–2) was csPCa. Per-lobe analysis, which included 60 (IQR: 25–73) ‘additional’ lesions/reader, yielded similar results.ConclusionsExperience significantly impacted lesion characterization using PI-RADSv2.1 descriptors. As compared to PI-RADSv2, PI-RADSv2.1 tended to downgrade non-csPCa lesions, but this effect was small and variable across readers.

Development and clinical utility analysis of a prostate zonal segmentation model on T2-weighted imaging: a multicenter study

ObjectivesTo automatically segment prostate central gland (CG) and peripheral zone (PZ) on T2-weighted imaging using deep learning and assess the model’s clinical utility by comparing it with a radiologist annotation and analyzing relevant influencing factors, especially the prostate zonal volume.MethodsA 3D U-Net-based model was trained with 223 patients from one institution and tested using one internal testing group (n = 93) and two external testing datasets, including one public dataset (ETDpub, n = 141) and one private dataset from two centers (ETDpri, n = 59). The Dice similarity coefficients (DSCs), 95th Hausdorff distance (95HD), and average boundary distance (ABD) were calculated to evaluate the model’s performance and further compared with a junior radiologist’s performance in ETDpub. To investigate factors influencing the model performance, patients’ clinical characteristics, prostate morphology, and image parameters in ETDpri were collected and analyzed using beta regression.ResultsThe DSCs in the internal testing group, ETDpub, and ETDpri were 0.909, 0.889, and 0.869 for CG, and 0.844, 0.755, and 0.764 for PZ, respectively. The mean 95HD and ABD were less than 7.0 and 1.3 for both zones. The U-Net model outperformed the junior radiologist, having a higher DSC (0.769 vs. 0.706) and higher intraclass correlation coefficient for volume estimation in PZ (0.836 vs. 0.668). CG volume and Magnetic Resonance (MR) vendor were significant influencing factors for CG and PZ segmentation.ConclusionsThe 3D U-Net model showed good performance for CG and PZ auto-segmentation in all the testing groups and outperformed the junior radiologist for PZ segmentation. The model performance was susceptible to prostate morphology and MR scanner parameters.

Test-retest repeatability of ADC in prostate using the multi b-Value VERDICT acquisition

PurposeVERDICT (Vascular, Extracellular, Restricted Diffusion for Cytometry in Tumours) MRI is a multi b-value, variable diffusion time DWI sequence that allows generation of ADC maps from different b-value and diffusion time combinations. The aim was to assess precision of prostate ADC measurements from varying b-value combinations using VERDICT and determine which protocol provides the most repeatable ADC. Materials and MethodsForty-one men (median age: 67.7 years) from a prior prospective VERDICT study (April 2016–October 2017) were analysed retrospectively. Men who were suspected of prostate cancer and scanned twice using VERDICT were included. ADC maps were formed using 5b-value combinations and the within-subject standard deviations (wSD) were calculated per ADC map. Three anatomical locations were analysed per subject: normal TZ (transition zone), normal PZ (peripheral zone), and index lesions. Repeated measures ANOVAs showed which b-value range had the lowest wSD, Spearman correlation and generalized linear model regression analysis determined whether wSD was related to ADC magnitude and ROI size. ResultsThe mean lesion ADC for b0b1500 had the lowest wSD in most zones (0.18–0.58x10-4 mm2/s). The wSD was unaffected by ADC magnitude (Lesion: p = 0.064, TZ: p = 0.368, PZ: p = 0.072) and lesion Likert score (p = 0.95). wSD showed a decrease with ROI size pooled over zones (p = 0.019, adjusted regression coefficient = -1.6x10-3, larger ROIs for TZ versus PZ versus lesions). ADC maps formed with a maximum b-value of 500 s/mm2 had the largest wSDs (1.90–10.24x10-4 mm2/s). ConclusionADC maps generated from b0b1500 have better repeatability in normal TZ, normal PZ, and index lesions.

The Influence of Moisture Content on Energy Losses in the Steam Turbine Last Stages

A method for calculating energy losses due to moisture content is presented, which takes into account the intra-channel and peripheral separation in condensing steam turbine LPC last stages and the actual moisture distribution over the stage height. It is shown that with the consideration of peripheral and intra-channel separation in the stage with a 1200-mm long rotor blade, the losses due to moisture content are decreased by 1.3% and, accordingly, stage efficiency hrist is increased by the same value. If the separated moisture is distributed taking into account the location of the intra-channel separation slots, and the separated peripheral moisture is distributed according to a linear law in the stage upper quarter, the real moisture content value at the periphery will decrease by 8%. This will make it possible to more accurately take into account the rotor blade droplet impingement erosion at the blade peripheral zone inlet section. It is recommended to calculate the energy losses due to moisture content not in the internal relative efficiency hri as part of additional losses, but inside the blade efficiency hrb, because these losses take place in the stage cascades, unlike other types of additional losses. This approach will help more accurately determine the following flow characteristics in the stage: relative velocities M1 and M2, velocity coefficients in the nozzle j and rotor y cascades, stage reaction ratio r, etc.

Prostate-specific antigen density as the best predictor of low- to intermediate-risk prostate cancer: a cohort study.

Evaluation of prostate cancer (PCa) when serum prostate-specific antigen (PSA) level is vaguely elevated is complicated. This is because serum PSA levels only reflect the number of prostate epithelial cells. We aimed to compare PSA and various prostate volume-related factors to determine which one can best predict PCa in patients with a PSA level of 2.5-20 ng/mL. Patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy at the Inje University Sanggye Paik Hospital between January 2018 and July 2021 and who had a PSA level of 2.5-20 ng/mL were retrospectively identified (n=275). Among them, based on biopsy results, patients were divided into cancer group and non-cancer groups, and age, PSA, total prostate volume (TPV), peripheral zone volume (PZV), peripheral zone PSA density (PZ-PSAD), transitional zone-PSAD (TZ-PSAD), and PSAD were compared and analyzed using receiver operating characteristic (ROC) and univariate analyses. The areas under ROC curves (AUCs) for age, total PSA, TPV, PZV, PZ-PSAD, TZ-PSAD, and PSAD for predicting PCa in patients with a PSA level of 2.5-20.0 ng/mL were 0.678, 0.680, 0.671, 0.639, 0.731, 0.736, and 0.764, respectively. In univariate and multivariate analysis, all categorical variables were divided based on the cut-off value and used to predict PCa. Those with a PSAD of ≥0.218 ng/mL2 were found to be at an increased risk of PCa than those with a PSAD of <0.218 ng/mL2 [odds ratio (OR) =3.51; 95% confidence interval (CI): 1.306-9.415], which was the best result, followed by TZ-PSAD with a cut-off value of 0.353. At a PSAD level of 0.218 ng/mL2, 85.0% of the PCa group could avoid unnecessary biopsy and 61.4% of the non-PCa group could reduce missed diagnosis when the TRUS findings were inaccurate. PSAD may inform biopsy decisions as the best predictor of PCa when TRUS findings are ambiguous in patients with a PSA level of 2.5-20.0 ng/mL.

Comparison of Strain and Shear Wave Elastography in Prostate Cancer Detection.

The aim of the study was to compare strain elastography with shear wave elastography in prostate cancer detection by comparing data gained during elastography with histological analysis after prostatectomy. Thirty patients with prostate cancer qualified for radical prostatectomy were enrolled into the study. All patients underwent transrectal strain elastography and shear wave elastography during pre-surgical evaluation. In each prostate, 36 regions were evaluated separately whether there was a suspicious prostate cancer lesion or not. Subsequently, the same regions were analyzed during histological analysis of the resected gland. Strain elastography and shear wave elastography (overall stiffness cutoff value=35 kPa) in our study were characterized by overall sensitivities of 58.9% and 65.3% and specificities of 71.8% and 70.2%, respectively. Cutoff values specific to the zones in the shear wave elastography examination (peripheral zone: 35 kPa, transitional zone: 45 kPa) were characterized by an overall prostate cancer detection sensitivity and specificity of 63.4% and 73% respectively. Shear wave elastography examination revealed a higher sensitivity versus strain elastography, 63.4% versus 58.9% (p=0.038, p < 0.05), and comparable specificity, 73.0% versus 71.8% (p=0.547, p > 0.05), respectively. Sensitivity in prostate cancer detection for both methods is higher for larger lesions (except Gleason score 5 massive lesions in strain elastography). Controversially we observed a decrease in sensitivity for strain elastography in the detection of lesions with a large diameter and a Gleason score of 5 near the prostate capsule. Overall sensitivity in the diagnosis of prostate cancer is more significant for shear wave elastography versus strain elastography.

New Methodology of Human Health Express Diagnostics Based on Pulse Wave Measurements and Occlusion Test

Nowadays, with the increase in the rhythm of life, the relevance of using express diagnostics methods for human health state estimation has significantly increased. We present a new express diagnostics method based on non-invasive measurements (the pulse wave shape, heart rate, blood pressure, and oxygen saturation of blood vessels and tissues). A feature of these measurements is that they can be carried out both in the hospital and at home. The new compact and portable optical hardware-software complex has been developed to measure tissue oxygen saturation. This complex makes it possible to reduce the measurement time from 60 min to 7-8 min, which reduces the likelihood of artifacts in the measurement process and increases its reliability. A new technique has been developed to carry out these measurements. A new optical sensor based on a line of charge-coupled devices has been developed to register a pulse wave in the far peripheral zone. The developed new technique for processing the pulse waveform and data on the oxygen saturation of hemoglobin in the blood and tissues allows a person to obtain additional information about their state of health independently. It will help to make conclusions about taking the necessary measures. This additional information allows the attending physician to provide more effective control over the course of treatment of the patient at any time since the methods of express diagnostics proposed by us have no restrictions on the number of applications. The functional state of more than 300 patients was studied. The results of various measurements are presented.

Extracapsular extension of transitional zone prostate cancer miss-detected by multiparametric magnetic resonance imaging.

To demonstrate the importance of extracapsular extension (ECE) of transitional zone (TZ) prostate cancer (PCa), examine the causes of its missed detection by Mp-MRI, and develop a new predictive model by integrating multi-level clinical variables. This retrospective study included 304 patients who underwent laparoscopic radical prostatectomy after 12 + X needle transperineal transrectal ultrasound (TRUS)-MRI-guided targeted prostate biopsy from 2018 to 2021 in our center was performed. In this study, the incidence rates of ECE were similar in patients with MRI lesions in the peripheral zone (PZ) and TZ (P = 0.66). However, the missed detection rate was higher in patients with TZ lesions than in those with PZ lesions (P < 0.05). These missed detections result in a higher positive surgical margin rate (P < 0.05). In patients with TZ lesions, detected MP-MRI ECE may have grey areas: the longest diameters of the MRI lesions were 16.5-23.5mm; MRI lesion volumes were 0.63-2.51ml; MRI lesion volume ratios were 2.75-8.86%; PSA were 13.85-23.05ng/ml. LASSO regression was used to construct a clinical prediction model for predicting the risk of ECE in TZ lesions from the perspective of MRI and clinical features, including four variables: the longest diameter of MRI lesions, TZ pseudocapsule invasion, ISUP grading of biopsy pathology, and number of positive biopsy needles. Patients with MRI lesions in the TZ have the same incidence of ECE as those with lesions in the PZ, but a higher missed detection rate.

Correlation between ADC, ADC ratio, and Gleason Grade group in prostate cancer patients undergoing radical prostatectomy: Retrospective multicenter study with different MRI scanners.

MRI is an important tool in the prostate cancer work-up, with special emphasis on the ADC sequence. This study aimed to investigate the correlation between ADC and ADC ratio compared to tumor aggressiveness determined by a histopathological examination after radical prostatectomy. Ninety-eight patients with prostate cancer underwent MRI at five different hospitals prior to radical prostatectomy. Images were retrospectively analyzed individually by two radiologists. The ADC of the index lesion and reference tissues (contralateral normal prostatic, normal peripheral zone, and urine) was recorded. Absolute ADC and different ADC ratios were compared to tumor aggressivity according to the ISUP Gleason Grade Groups extracted from the pathology report using Spearman's rank correlation coefficient (ρ). ROC curves were used to evaluate the ability to discriminate between ISUP 1-2 and ISUP 3-5 and intra class correlation and Bland-Altman plots for interrater reliability. All patients had prostate cancer classified as ISUP grade ≥ 2. No correlation was found between ADC and ISUP grade. We found no benefit of using the ADC ratio over absolute ADC. The AUC for all metrics was close to 0.5, and no threshold could be extracted for prediction of tumor aggressivity. The interrater reliability was substantial to almost perfect for all variables analyzed. ADC and ADC ratio did not correlate with tumor aggressiveness defined by ISUP grade in this multicenter MRI study. The result of this study is opposite to previous research in the field.

Transverse prostate maximum sectional area can predict clinically significant prostate cancer in PI-RADS 3 lesions at multiparametric magnetic resonance imaging.

To evaluate multiparametric magnetic resonance imaging (mpMRI) parameters, such as TransPA (transverse prostate maximum sectional area), TransCGA (transverse central gland sectional area), TransPZA (transverse peripheral zone sectional area), and TransPAI (TransPZA/TransCGA ratio) in predicting prostate cancer (PCa) in prostate imaging reporting and data system (PI-RADS) 3 lesions. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), the area under the receiver operating characteristic curve (AUC), and the best cut-off, were calculated. Univariate and multivariate analyses were carried out to evaluate the capability to predict PCa. Out of 120 PI-RADS 3 lesions, 54 (45.0%) were PCa with 34 (28.3%) csPCas. Median TransPA, TransCGA, TransPZA and TransPAI were 15.4cm2, 9.1cm2, 5.5cm2 and 0.57, respectively. At multivariate analysis, location in the transition zone (OR=7.92, 95% CI: 2.70-23.29, P<0.001) and TransPA (OR=0.83, 95% CI: 0.76-0.92, P<0.001) were independent predictors of PCa. The TransPA (OR=0.90, 95% CI: 0.082-0.99, P=0.022) was an independent predictor of csPCa. The best cut-off of TransPA for csPCa was 18 (Sensitivity 88.2%, Specificity 37.2%, PPV 35.7%, NPV 88.9%). The discrimination (AUC) of the multivariate model was 0.627 (95% CI: 0.519-0.734, P<0.031). In PI-RADS 3 lesions, the TransPA could be useful in selecting patients requiring biopsy.

Intraobserver and Interobserver Agreement between Six Radiologists Describing mpMRI Features of Prostate Cancer Using a PI-RADS 2.1 Structured Reporting Scheme.

Clinical practice has revealed ambiguities in PI-RADS v2.1 scoring, but a limited number of studies are available that validate the interreader and intrareader reproducibility of the mpMRI PI-RADS lexicon. We decomposed the PI-RADS rules into a set of common data elements to evaluate the inter- and intraobserver agreement in assessing the individual features included in the PI-RADS lexicon. Six radiologists (three highly experienced, three less experienced) in two sessions independently read thirty-two lesions in the peripheral and transition zone using the structured reporting tool, blinded to clinical MRI indication. The highest agreement between radiologists was observed for the abnormality detection, the evaluation of the type of signal intensity, and the characteristic of benign prostatic hyperplasia. Moderate agreement was reported for dynamic contrast-enhanced images. This resulted in a decrease in abnormality detection (PA = 76.5%) and enhancement indication (PA = 77.3%). The lowest agreement was observed for highly subjective features: shape, signal intensity level, and type of lesion margins. The results indicate the limitations of the PI-RADS v2.1 lexicon in relation to interreader and intrareader reproducibility. We have demonstrated that it is possible to develop structured reporting systems standardized according to the PI-RADS lexicon.

Investigation of a low emission peripheral vortex reverse flow (PVRF) combustor fuelled by LPG and ethylene

Peripheral Vortex Reverse Flow (PVRF) combustor is characterized by a strong peripheral recirculation zone resulting in stable combustion and low pollutant emissions. In this study, a PVRF combustor is investigated in the premixed and non-premixed modes with LPG and ethylene fuels at a maximum heat load of 6.25 kW and thermal intensity of 25 MW/m3-atm, relevant to gas turbine combustors. The fuel is injected co-axially, with respect to the air jet, using two different fuel injection diameters of 1 mm, and 2 mm. For both the fuels, the fuel injection velocity is higher as compared to the air injection velocity for fuel injection diameter of 1 mm, while it is lower for fuel injection diameter of 2 mm. CH* chemiluminescence images are acquired, and CO and NOx emissions are measured. Reynolds Averaged Navier Stokes (RANS) simulations are carried out at an equivalence ratio of 0.8 using the Eddy Dissipation Concept (EDC) model with a H2/CO/C1–C4 mechanism comprising of 50 species and 373 reactions. Delayed ignition and downstream shifting of the reaction zone facilitating higher product gas entrainment prior to reactions is observed in the non-premixed mode as compared to the premixed mode. NOx emissions were found to be lower in the non-premixed mode as compared to the premixed mode for both the fuels. This is possibly due to suppression of NO formation in the reaction zone via. prompt route which is also supported by lower CH* chemiluminescence intensity in the non-premixed mode. With LPG, the case with larger fuel injection diameter showed further delayed mixing as compared to the case with smaller fuel injection diameter, and resulted in even lower NOx emissions. For all the cases, CO emissions were of similar levels in the non-premixed and premixed modes suggesting that lower NOx emissions in the non-premixed mode is not at the expense of increase in CO emissions. Overall, the investigation shows that lower NOx emissions can be achieved in the non-premixed mode as compared to the premixed mode if more product gas entrainment is facilitated prior to the reactions by delayed mixing between fuel and oxidizer.

Effectiveness and Accuracy of MRI-Ultrasound Fusion Targeted Biopsy Based on PI-RADS v2.1 Category in Transition/Peripheral Zone of the Prostate.

MRI-ultrasound fusion targeted biopsy (MRI-TBx) improves the clinically significant prostate cancer (csPCa) detection with fewer cores. However, whether systematic biopsy-guided by transrectal ultrasound (TRUS-SBx) can be omitted when undergoing MRI-TBx in transition zone (TZ) and peripheral zone (PZ) remains unclear. To assess the performance and effectiveness of MRI-TBx based on PI-RADS v2.1 for csPCa diagnosis in TZ and PZ, respectively. Retrospective. A total of 309 selected cases (median age 70 years) with 356 lesions who underwent both MRI-TBx and TRUS-SBx were enrolled. A 3.0 T, multiparametric MRI (mp-MRI) including T2-weighted turbo-spin echo imaging (T2WI), diffusion-weighted spin-echo echo planar imaging (DWI), dynamic contrast-enhanced MRI with time-resolved T1-weighted imaging (DCE). Mp-MRI was assessed by two radiologists using PI-RADS v2.1. The csPCa detection rates provided by MRI-TBx, TRUS-SBx and combined biopsy in TZ and PZ were calculated, respectively. McNemar test was used to compare the csPCa detection rates in TZ and PZ, respectively. The frequencies and distribution of all detected prostate cancers by different biopsy methods were also compared. P < 0.05 was considered statistically significant. Among 356 lesions in 309 patients, 208 (68 in TZ, 140 in PZ) were pathologically confirmed as csPCa. In TZ, there were significant differences for csPCa detection with PI-RADS 3 between combined biopsy and TRUS-SBx (23.5% vs. 15.3%), MRI-TBx (23.5% vs. 16.3%), respectively. MRI-TBx detected 23% (19/83) cases missed by TRUS-SBx in which 68% (13/19) were csPCa. In PZ, there were no statistical differences between MRI-TBx and combined biopsy with PI-RADS 3-5 (P=0.21, 0.25, 0.07, respectively). In 9% (14/152) cases only detected by MRI-TBx, 86% (12/14) were clinically significant. Five percent (7/152) of cases only detected by TRUS-SBx were completely nonclinically significant. MRI-TBx played a positive role on csPCa diagnosis in TZ, but combined biopsy might be the best choice especially in the subgroup PI-RADS 3. In PZ, MRI-TBx had an advantage over TRUS-SBx for csPCa detection. 2. Stage 2.