Vendor Platforms Research Articles

Spleen stiffness in a healthy pediatric population undergoing liver magnetic resonance elastography.

Splenic stiffness is a potential imaging marker of portal hypertension. Normative spleen stiffness values are needed to define diagnostic thresholds. To report stiffness measurements of the spleen in healthy children undergoing liver magnetic resonance (MR) elastography across MRI vendors and field strengths. This was a post-hoc analysis of data collected under a prospective multicenter cross-sectional study. Volunteers aged 7-17.9years without a known history of liver or spleen disease were recruited for a research MRI between February 2018 and October 2019. Gradient recalled echo (GRE) or spin-echo-echo-planar imaging (SE-EPI) MR elastography was performed on a total of three vendor platforms and at two field strengths (1.5T (T) and 3T) with standard right upper quadrant passive driver placement (frequency of 60Hz). Two independent reviewers measured spleen stiffness, length, and volume. Descriptive statistics, independent sample t-tests or Mann-Whitney test, and Pearson's or Spearman's correlation were used. From 101 study volunteers, 72 (34 female) had measurable splenic stiffness. Median age was 12years (interquartile range [IQR], 9.9-14.9years). Mean (± SD) spleen stiffness was 4.7 ± 0.9kPa (IQR, 3.8-5.4kPa) with 6.1kPa reflecting the 95th percentile. Strong correlation was observed between reviewers (ICC = 0.89 [95%CI, 0.71-0.93; P < 0.001]). Male volunteers had slightly higher splenic stiffness compared to females: 4.9 ± 0.9 vs. 4.3 ± 0.8kPa (P = 0.014). There was significant correlation between spleen stiffness and body mass index (r = 0.33 [95%CI, 0.06-0.56; P = 0.024]) but no other measure of patient size (r = 0.15-0.29). No significant difference in spleen stiffness was observed across vendors (P = 0.089) or field strengths (P = 0.236). MR elastography-based spleen stiffness, measured as part of a liver MR elastography acquisition, is < 6.1kPa in a healthy pediatric population and does not vary with MRI vendor or field strength.

Metric learning guided sinogram denoising for cone beam CT enhancement.

Cone beam computed tomography (CBCT) is a widely available modality, but its clinical utility has been limited by low detail conspicuity and quantitative accuracy. Convenient post-reconstruction denoising is subject to back projected patterned residual, but joint denoise-reconstruction is typically computationally expensive and complex. In this study, we develop and evaluate a novel Metric-learning guided wavelet transform reconstruction (MEGATRON) approach to enhance image domain quality with projection-domain processing. Projection domain based processing has the benefit of being simple, efficient, and compatible with various reconstruction toolkit and vendor platforms. However, they also typically show inferior performance in the final reconstructed image, because the denoising goals in projection and image domains do not necessarily align. Motivated by these observations, this work aims to translate the demand for quality enhancement from the quantitative image domain to the more easily operable projection domain. Specifically, the proposed paradigm consists of a metric learning module and a denoising network module. Via metric learning, enhancement objectives on the wavelet encoded sinogram domain data are defined to reflect post-reconstruction image discrepancy. The denoising network maps measured cone-beam projection to its enhanced version, driven by the learnt objective. In doing so, the denoiser operates in the convenient sinogram to sinogram fashion but reflects improvement in reconstructed image as the final goal. Implementation-wise, metric learning was formalized as optimizing the weighted fitting of wavelet subbands, and a res-Unet, which is a Unet structure with residual blocks, was used for denoising. To access quantitative reference, cone-beam projections were simulated using the X-ray based Cancer Imaging Simulation Toolkit (XCIST). In both learning modules, a data set of 123 human thoraxes, which was from Open-Source Imaging Consortium (OSIC) Pulmonary Fibrosis Progression challenge, was used. Reconstructed CBCT thoracic images were compared against ground truth FB and performance was assessed in root mean square error (RMSE), peak signal-to-noise ratio (PSNR), and structural similarity index (SSIM). MEGATRON achieved RMSE in HU value, PSNR, and SSIM were 30.97±4.25, 37.45±1.78, and 93.23±1.62, respectively. These values are on par with reported results from sophisticated physics-driven CBCT enhancement, demonstrating promise and utility of the proposed MEGATRON method. We have demonstrated that incorporating the proposed metric learning into sinogram denoising introduces awareness of reconstruction goal and improves final quantitative performance. The proposed approach is compatible with a wide range of denoiser network structures and reconstruction modules, to suit customized need or further improve performance.

AAPM Task Group Report 325: MRI static magnetic field homogeneity measurement and evaluation procedures - Guidance and resources.

Measurement of static magnetic field (B0) homogeneity is an essential component of routine MRI system evaluation. This report summarizes the work of AAPM Task Group (TG) 325 on vendor-specific methods of B0 homogeneity measurement and evaluation. TG 325 was charged with producing a set of detailed, step-by-step instructions to implement B0 homogeneity measurement methods discussed in the American College of Radiology (ACR) MRI Quality Control Manual using specific makes and models of MRI scanners. The TG produced such instructions for as many approaches as was relevant and practical on six currently available vendor platforms including details of software/tools, settings, phantoms, and other experimental details needed for a reproducible protocol. Because edits to these instructions may need to be made as vendors enter and exit the market and change available tools, interfaces, and access levels over time, the step-by-step instructions are published as a living document on the AAPM website. This summary document provides an introduction to B0 homogeneity testing in MRI and several of the common methods for its measurement and evaluation. A living document on the AAPM website provides vendor-specific step-by-step instructions for performing these tests to facilitate accurate and reproducible B0 homogeneity evaluation on a routine basis.

Imaging cholangiocarcinoma: CT and MRI techniques.

Cross-sectional imaging plays a crucial role in the detection, diagnosis, staging, and resectability assessment of intra- and extrahepatic cholangiocarcinoma. Despite this vital function, there is a lack of standardized CT and MRI protocol recommendations for imaging cholangiocarcinoma, with substantial differences in image acquisition across institutions and vendor platforms. In this review, we present standardized strategies for the optimal imaging assessment of cholangiocarcinoma including contrast media considerations, patient preparation recommendations, optimal contrast timing, and representative CT and MRI protocols with individual sequence optimization recommendations. Our recommendations are supported by expert opinion from members of the Society of Abdominal Radiology's Disease-Focused Panel (DFP) on Cholangiocarcinoma, encompassing a broad array of institutions and practice patterns.

Improvements in Between-Vendor MRI Harmonization of Renal T2 Mapping using Stimulated Echo Compensation.

T2 mapping is valuable to evaluate pathophysiology in kidney disease. However, variations in T2 relaxation time measurements across MR scanners and vendors may occur requiring additional correction. To harmonize renal T2 measurements between MR vendor platforms, and use an extended-phase-graph-based fitting method ("StimFit") to correct stimulated echoes and reduce between-vendor variations. Prospective. 8 healthy "travelling" volunteers (37.5% female, 32 ± 6 years) imaged on four MRI systems across three vendors at four sites, 10 healthy volunteers (50% female, 32 ± 8 years) scanned multiple times on a given MR scanner for repeatability evaluation. ISMRM/NIST system phantom scanned for evaluation of T2 accuracy. 3T, multiecho spin-echo sequence. T2 images fit using conventional monoexponential fitting and "StimFit." Mean absolute percentage error (MAPE) of phantom measurements with reference T2 values. Average cortex and medulla T2 values compared between MR vendors, with masks obtained from T2-weighted images and T1 maps. Full-width-at-half-maximum (FWHM) T2 distributions to evaluate local homogeneity of measurements. Coefficient of variation (CV), linear mixed-effects model, analysis of variance, student's t-tests, Bland-Altman plots, P-value <0.05 considered statistically significant. In the ISMRM/NIST phantom, "StimFit" reduced the MAPE from 4.9%, 9.1%, 24.4%, and 18.1% for the four sites (three vendors) to 3.3%, 3.0%, 6.6%, and 4.1%, respectively. In vivo, there was a significant difference in kidney T2 measurements between vendors using a monoexponential fit, but not with "StimFit" (P = 0.86 and 0.92, cortex and medulla, respectively). The intervendor CVs of T2 measures were reduced from 8.0% to 2.6% (cortex) and 7.1% to 2.8% (medulla) with StimFit, resulting in no significant differences for the CVs of intravendor repeat acquisitions (P = 0.13 and 0.05). "StimFit" significantly reduced the FWHM of T2 distributions in the cortex and whole kidney. Stimulated-echo correction reduces renal T2 variation across MR vendor platforms. 2 TECHNICAL EFFICACY: Stage 1.

Successes and Barriers of Health Information Exchange Participation Across Hospitals in South Carolina From 2014 to 2020: Longitudinal Observational Study.

The 2009 Health Information Technology for Economic and Clinical Health Act sets three stages of Meaningful Use requirements for the electronic health records incentive program. Health information exchange (HIE) technologies are critical in the meaningful use of electronic health records to support patient care coordination. However, HIE use trends and barriers remain unclear across hospitals in South Carolina (SC), a state with the earliest HIE implementation. This study aims to explore changes in the proportion of HIE participation and factors associated with HIE participation, and barriers to exchange and interoperability across SC hospitals. This study derived data from a longitudinal data set of the 2014-2020 American Hospital Association Information Technology Supplement for 69 SC hospitals. The primary outcome was whether a hospital participated in HIE in a year. A cross-sectional multivariable logistic regression model, clustered at the hospital level and weighted by bed size, was used to identify factors associated with HIE participation. The second outcome was barriers to sending, receiving, or finding patient health information to or from other organizations or hospital systems. The frequency of hospitals reporting each barrier related to exchange and interoperability were then calculated. Hospitals in SC have been increasingly participating in HIE, improving from 43% (24/56) in 2014 to 82% (54/66) in 2020. After controlling for other hospital factors, teaching hospitals (adjusted odds ratio [AOR] 3.7, 95% CI 1.0-13.3), system-affiliated hospitals (AOR 6.6, 95% CI 3.2-13.7), and rural referral hospitals (AOR 8.0, 95% CI 1.2-53.4) had higher odds to participate in HIE than their counterparts, whereas critical access hospitals (AOR 0.1, 95% CI 0.02-0.6) were less likely to participate in HIE than their counterparts reimbursed by the prospective payment system. Hospitals with greater ratios of Medicare or Medicaid inpatient days to total inpatient days also reported higher odds of HIE participation. Despite the majority of hospitals reporting HIE participation in 2020, barriers to exchange and interoperability remained, including lack of provider contacts (27/40, 68%), difficulty in finding patient health information (27/40, 68%), adapting different vendor platforms (26/40, 65%), difficulty matching or identifying same patients between systems (23/40, 58%), and providers that do not typically exchange patient data (23/40, 58%). HIE participation has been widely adopted in SC hospitals. Our findings highlight the need to incentivize optimization of HIE and seamless information exchange by facilitating and implementing standardization of health information across various HIE systems and by addressing other technical issues, including providing providers' addresses and training HIE stakeholders to find relevant information. Policies and efforts should include more collaboration with vendors to reduce platform compatibility issues and more user engagement and technical training and support to facilitate effective, accurate, and efficient exchange of provider contacts and patient health information.

The move to T1: Why are we talking about it?

The move to a one-day settlement cycle (T1) in the US will encourage market participants to streamline settlement processes and reduce associated risk. A recent statistic from a tier one bank showed that, based on a trading volume of EUR2.5bn per day, almost 30 per cent of this (EUR700m) is locked up due to failing trades. An 80 per cent reduction in time given to settle means sustaining settlement rates will be challenging for organisations unless fundamental changes to processes are made. These changes fall into three categories: behavioural, procedural and technological. To make behavioural changes, organisations should: understand root causes of failures to increase efficiency, such as the need for several rounds of matching; maximise automation so teams in all regions have access to the same better-quality data across time-zones via the same infrastructure; and adopt data-sharing protocols for a more collaborative ecosystem with greater access to data. Procedural changes include changing batch times, giving middle and back-offices visibility into inventory and ensuring Standing Settlement Instructions are readily available and properly maintained to combat multiple in-house and vendor platforms that do not communicate. Technological advancements include the move to streamline technology stacks and operate through fewer settlement systems, avoiding the need to manage data in Excel spreadsheets and multiple platforms. Single-source providers like AccessFintech offer connectivity to vendors and drive down additional application programming interface (API) connection build costs. The market must focus on increasing automation and better interoperability and data sharing between counterparties to prepare for a proposed go live in 2024.

An Examination of Academic Library Privacy Policy Compliance with Professional Guidelines

Objective – The tension between upholding privacy as a professional value and the ubiquity of collecting patrons’ data to provide online services is now common in libraries. Privacy policies that explain how the library collects and uses patron records are one way libraries can provide transparency around this issue. This study examines 78 policies collected from the public websites of U.S. Association of Research Libraries’ (ARL) members and examines these policies for compliance with American Library Association (ALA) guidelines on privacy policy content. This overview can provide library policy makers with a sense of trends in the privacy policies of research-intensive academic libraries, and a sense of the gaps where current policies (and guidelines) may not adequately address current privacy concerns. Methods – Content analysis was applied to analyze all privacy policies. A deductive codebook based on ALA privacy policy guidelines was first used to code all policies. The authors used consensus coding to arrive at agreement about where codes were present. An inductive codebook was then developed to address themes present in the text that remained uncoded after initial deductive coding. Results – Deductive coding indicated low policy compliance with ALA guidelines. None of the 78 policies contained all 20 codes derived from the guidelines, and only 6% contained more than half. No individual policy contained more than 75% of the content recommended by ALA. Inductive coding revealed themes that expanded on the ALA guidelines or addressed emerging privacy concerns such as library-initiated data collection and sharing patron data with institutional partners. No single inductive code appeared in more than 63% of policies. Conclusion – Academic library privacy policies appear to be evolving to address emerging concerns such as library-initiated data collection, invisible data collection via vendor platforms, and data sharing with institutional partners. However, this study indicates that most libraries do not provide patrons with a policy that comprehensively addresses how patrons’ data are obtained, used, and shared by the library.

Creation of a Multi-vendor Image-Sharing Solution.

Transferring medical imaging studies from one institution to another is a common occurrence in today's medical practice. For the past two decades, radiology departments have relied on physical media (compact discs and digital video disks) and human couriers to accomplish image transfer. This mode of transfer is slow, prone to failure, and reliant on outdated technology. To address these shortcomings, multiple image-sharing vendors have created electronic, cloud-based solutions. While these solutions solve multiple problems, a new problem has been introduced: it is difficult to send or receive images across image-sharing platforms. In this work, we describe how we have developed a solution to share images across multiple vendor platforms.

National Trends in Telestroke Utilization in a US Commercial Platform Prior to the COVID-19 Pandemic

ObjectivesMost data on telestroke utilization come from single academic hub-and-spoke telestroke networks. Our objective was to describe characteristics of telestroke consultations among a national sample of telestroke sites on one of the most commonly used common vendor platforms, prior to the COVID-19 public health emergency. Materials and methodsA commercial telestroke vendor provided data on all telestroke consultations by two specialist provider groups from 2013-2019. Kendall's τ β nonparametric test was utilized to assess time trends. Generalized linear models were used to assess the association between hospital consult utilization and alteplase use adjusting for hospital characteristics. ResultsAmong 67,736 telestroke consultations to 132 spoke sites over the study period, most occurred in the emergency department (90%) and for stroke indications (final clinical diagnoses: TIA 13%, ischemic stroke 39%, hemorrhagic stroke 2%, stroke mimics 46%). Stroke severity was low (median NIHSS 2, IQR 0–6). Alteplase was recommended for 23% of ischemic stroke patients. From 2013 to 2019, times from ED arrival to NIHSS, CT scan, imaging review, consult, and alteplase administration all decreased (p<0.05 for all), while times from consult start to alteplase recommendation and bolus increased (p<0.01 for both). Transfer was recommended for 8% of ischemic stroke patients. Number of patients treated with alteplase per hospital increased with increasing number of consults and hospital size and was also associated with US region in unadjusted and adjusted analyses. Longer duration of hospital participation in the network was associated with shorter hospital median door-to-needle time for alteplase delivery (39 min shorter per year, p=0.04). ConclusionsAmong spoke sites using a commercial telestroke platform over a seven-year time horizon, times to consult start and alteplase bolus decreased over time. Similar to academic networks, duration of telestroke participation in this commercial network was associated with faster alteplase delivery, suggesting practice improves performance.

Determination of Abundant Metabolite Matrix Adducts Illuminates the Dark Metabolome of MALDI-Mass Spectrometry Imaging Datasets.

Spatial metabolomics using mass spectrometry imaging (MSI) is a powerful tool to map hundreds to thousands of metabolites in biological systems. One major challenge in MSI is the annotation of m/z values, which is substantially complicated by background ions introduced throughout the chemicals and equipment used during experimental procedures. Among many factors, the formation of adducts with sodium or potassium ions, or in case of matrix-assisted laser desorption ionization (MALDI)-MSI, the presence of abundant matrix clusters strongly increases total m/z peak counts. Currently, there is a limitation to identify the chemistry of the many unknown peaks to interpret their biological function. We took advantage of the co-localization of adducts with their parent ions and the accuracy of high mass resolution to estimate adduct abundance in 20 datasets from different vendors of mass spectrometers. Metabolites ranging from lipids to amines and amino acids form matrix adducts with the commonly used 2,5-dihydroxybenzoic acid (DHB) matrix like [M + (DHB-H2O) + H]+ and [M + DHB + Na]+. Current data analyses neglect those matrix adducts and overestimate total metabolite numbers, thereby expanding the number of unidentified peaks. Our study demonstrates that MALDI-MSI data are strongly influenced by adduct formation across different sample types and vendor platforms and reveals a major influence of so far unrecognized metabolite–matrix adducts on total peak counts (up to one third). We developed a software package, mass2adduct, for the community for an automated putative assignment and quantification of metabolite–matrix adducts enabling users to ultimately focus on the biologically relevant portion of the MSI data.

MEDLINE search retrieval issues: A longitudinal query analysis of five vendor platforms.

This study compared the results of data collected from a longitudinal query analysis of the MEDLINE database hosted on multiple platforms that include PubMed, EBSCOHost, Ovid, ProQuest, and Web of Science. The goal was to identify variations among the search results on the platforms after controlling for search query syntax. We devised twenty-nine cases of search queries comprised of five semantically equivalent queries per case to search against the five MEDLINE database platforms. We ran our queries monthly for a year and collected search result count data to observe changes. We found that search results varied considerably depending on MEDLINE platform. Reasons for variations were due to trends in scholarly publication such as publishing individual papers online first versus complete issues. Some other reasons were metadata differences in bibliographic records; differences in the levels of specificity of search fields provided by the platforms and large fluctuations in monthly search results based on the same query. Database integrity and currency issues were observed as each platform updated its MEDLINE data throughout the year. Specific biomedical bibliographic databases are used to inform clinical decision-making, create systematic reviews, and construct knowledge bases for clinical decision support systems. They serve as essential information retrieval and discovery tools to help identify and collect research data and are used in a broad range of fields and as the basis of multiple research designs. This study should help clinicians, researchers, librarians, informationists, and others understand how these platforms differ and inform future work in their standardization.

The utility of second single antigen bead assay: Clearing the water or stirring up mud?

Though solid-phase single antigen bead (SAB) testing has provided major advances to the HLA community and organ allocation, it has not been without limitations. In particular, false-positive reactions lead to interpretative challenges and the potential to preclude a transplant if the corresponding antigens are deemed unacceptable. Two different vendor platforms are commercially available for SAB testing, one more recent than the other. The aim herein was to assess the benefit of using the newer SAB platform in situations where the primary platform yielded suspicious (specifically, false positive) reactions. Therefore, 42 serum samples with commonly encountered false-positive patterns observed in our laboratory were tested with the newer platform. Cases were classified as resolved, equivalent, or divergent based on whether the second platform produced no reactivity, the same pattern, or a distinctly different pattern compared to the primary platform, respectively. Approximately 33% of cases were resolved, 46% were equivalent, and 21% were divergent. The project revealed advantages of adding a second SAB platform to the laboratory’s test menu including resolving challenging samples and including broader coverage of different alleles and unique class II alpha/beta subunit combinations. However, the challenges of validating, maintaining, and billing for another test method in the laboratory may be barriers to routine use.

Normal Liver Stiffness Measured with MR Elastography in Children.

Background Stiffness thresholds for liver MR elastography in children vary between studies and may differ from thresholds in adults. Normative liver stiffness data are needed to optimize diagnostic thresholds for children. Purpose To determine normal liver stiffness, and associated normal ranges for children, as measured with MR elastography across vendors and field strengths. Materials and Methods This was a prospective multicenter cohort study (ClinicalTrials.gov identifier: NCT03235414). Volunteers aged 7-17.9 years without a known history of liver disease were recruited at four sites for a research MRI and blood draw between February 2018 and October 2019. MRI was performed on three vendor platforms and at two field strengths (1.5 T and 3.0 T). All MRI scans were centrally analyzed; stiffness, proton density fat fraction (PDFF), and R2* values were expressed as means of means. Mean and 95% confidence intervals (CIs) for liver stiffness were calculated. Pearson correlation coefficient (r), two-sample t test, or analysis of variance was used to assess univariable associations. Results Seventy-one volunteers had complete data and no documented exclusion criterion (median age, 12 years; interquartile range [IQR], 10-15 years; 39 female participants). Median body mass index percentile was 54% (IQR, 32.5%-69.5%). Mean liver stiffness was 2.1 kPa (95% CI: 2.0, 2.2 kPa) with mean ± 1.96 kPa standard deviation of 1.5-2.8 kPa. Median liver PDFF was 2.0% (IQR, 1.7%-2.6%). There was no association between liver stiffness and any patient variable or MRI scanner factor. Conclusion Mean liver stiffness measured with MR elastography in children without liver disease was 2.1 kPa (similar to that in adults). The 95th percentile of normal liver stiffness was 2.8 kPa. Liver stiffness was independent of sex, age, or body mass index and did not vary with MRI scanner vendor or field strength. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Yin in this issue.

The library has infinite streaming content, but are users infinitely content? The library catalog vs. vendor platform discovery

Despite the widespread adoption of streaming video by academic libraries, there has been little discussion about how video content is discovered and accessed through the library catalog as compared to vendor platforms. This article explores the current status of video resources in the library catalog to better understand how users find and access streaming content. MARC records were evaluated, and searches were performed to gauge issues related to metadata quality and its impact on discovery. The study reveals new trends in how users access streaming content for teaching, learning, and research.

Reproducibility and Intervendor Agreement of Left Ventricular Global Systolic Strain in Children Using a Layer-Specific Analysis

Speckle-tracking strain analysis provides additive data to the assessment of pediatric and congenital heart disease; however, the variety of strain analysis software platforms by different vendors and the lack of data on intervendor strain agreement in children have limited its utility. The purpose of this study is to evaluate the intervendor agreement of strain on two commonly used analysis platforms in pediatrics by layer of myocardium and data compression. This prospective study analyzed two-dimensional speckle-tracking strain on two software platforms in 53 children with normal cardiac segmental anatomy and varying function. Three standard apical views and one parasternal short-axis view were exported at their acquired frame rates to workstations with GE EchoPAC and TomTec software and then also to TomTec at compressed frame rates. Both software platforms had been updated with European Association of Cardiovascular Imaging/American Society of Echocardiography Task Force recommendations for left ventricular (LV) global strain. Intravendor and intervendor agreement between layer-specific comparisons were assessed using Bland-Altman analysis (limits of agreement and bias) and intraclass correlation coefficients. This study included subjects with normal LV function (n=38) and cardiomyopathy (n=15) with an age range of 1month to 18years. Intertechnique agreement by default vendor myocardial layer (GE mid-TomTec endocardial layer) was robust for both global longitudinal (GLS) and circumferential strain (GCS; higher for GLS than GCS). Intravendor (inter- and interreader) agreement was slightly higher than intervendor. Only small differences in intraclass correlation coefficients were present between various myocardial layers and acquired versus compressed TomTec data with narrow limits of agreement and small bias except in certain subgroup comparisons. Comparison of LV GLS and GCS between two commonly used software platforms after European Association of Cardiovascular Imaging/American Society of Echocardiography Industry Task Force recommendations demonstrated good to excellent agreement in pediatrics, regardless of the layer of analysis or the image format, although some degree of variability remains between vendor platforms. Overall, GLS agreement was more robust than GCS, and this difference is exaggerated in specific subanalyses. These data suggest that comparisons of strain values obtained on these two vendors will be reasonable, but caution should be used when the indication is the detection of small differences between serial echocardiograms.

HighResNPS.com: An Online Crowd-Sourced HR-MS Database for Suspect and Non-targeted Screening of New Psychoactive Substances.

The number of new psychoactive substances (NPS) is constantly increasing. However, although the number might be large, most NPS have a low prevalence of use, so keeping screening libraries updated with the relevant analytical targets becomes a challenge. One way to ensure sufficient screening coverage is to use shared high resolution-mass spectrometry (HR-MS) databases, such as HighResNPS.com: a free, online, spreadsheet-format, crowd-sourced HR-MS database for NPS screening. The aims of this study were (i) to present the database to the scientific community and (ii) to verify that the HighResNPS database can be utilized in suspect screening workflows for LC-HR-MS instruments and software from four different instrument vendors. A sample was spiked with 10 NPS, and participating laboratories then analyzed the sample with their respective HR-MS vendor platforms and the HighResNPS database. The HighResNPS data were obtained via a spreadsheet converted to fit the import specifications of the different vendor platforms. Suspect screening was performed using LC-HR-MS vendor platforms from Thermo Fisher, Waters, Bruker and Agilent. All 10 NPS were identified in at least three workflows used for the four different vendor platforms. Multiple users have submitted data to HighResNPS for the same NPS, which resulted in multiple true-positive identifications for these NPS. Suspect screening with LC-HR-MS can be based on diagnostic fragment ions reported by users of different vendor platforms and can support NPS identification in biological samples and/or seizure analyses when no reference standard is available in-house. The present work clearly demonstrates that HighResNPS data is compatible with instruments and screening software from at least four different vendor platforms. The database can thus serve as a useful add-on in LC-HR-MS screening workflows.

Left atrial strain reproducibility using vendor-dependent and vendor-independent software

BackgroundTwo-dimensional speckle-tracking echocardiography (2D-STE) enables objective assessment of left atrial (LA) deformation through the analysis of myocardial strain, which can be measured by different speckle-tracking software. The aim of this study was to compare the consistency of 3 different commercially available software, which include vendor-specific software for measuring left ventricle (VSSLV), vendor-independent software packages for measuring LV strain (VISLV) and vendor-independent software packages for measuring LA strain (VISLA).MethodsSixty-four subjects (mean age: 44 ± 16 years, 50% males) underwent conventional echocardiograms using a GE Vivid 9 (GE Ultrasound, Horten, Norway) cardiac ultrasound system. Standard apical 4 and 2 chamber views of the left atrium were obtained in each subject with a frame-rate range of 40–71 frames/s. LA strain during the contraction phase (Sct), conduit phase (Scd), reservoir phase (Sr = Sct + Scd) were analyzed by 2 independent observers and 3 different software.ResultsSct, Scd, Sr were, respectively, − 11.26 ± 2.45%, − 16.77 ± 7.06%, and 28.03 ± 7.58% with VSSLV, − 14.77 ± 3.59%, − 23.17 ± 10.33%, and 38.23 ± 10.99% with VISLV, and − 14.80 ± 3.88%, − 23.94 ± 10.48%, and 38.73 ± 11.56% when VISLA was used. A comparison of strain measurements between VSSLV and VIS (VISLV and VISLA) showed VIS had significantly smaller mean differences and narrower limits of agreement. Similar results were observed in the coefficient of variation (CV) for measurements between VSSLV and VIS (VISLV and VISLA). Comparison of the intra-class correlation coefficients (ICCs) indicated that measurement reliability was weaker with VSSLV (ICC < 0.6) than with VIS (VISLV and VISLA) (ICC > 0.9). For intra-observer ICCs, VISLA > VSSLV = VISLV. For inter-observer ICCs, VSSLV > VISLA > VISLV.ConclusionsSoftware measurement results of LA strain vary considerably. We recommended not measuring LA strain across vendor platforms.

FeatherNet

Convolutional Neural Network (ConvNet or CNN) algorithms are characterized by a large number of model parameters and high computational complexity. These two requirements have made it challenging for implementations on resource-limited FPGAs. The challenges are magnified when considering designs for low-end FPGAs. While previous work has demonstrated successful ConvNet implementations with high-end FPGAs, this article presents a ConvNet accelerator design that enables the implementation of complex deep ConvNet architectures on resource-constrained FPGA platforms aimed at the IoT market. We call the design “FeatherNet” for its light resource utilization. The implementations are VHDL-based providing flexibility in design optimizations. As part of the design process, new methods are introduced to address several design challenges. The first method is a novel stride-aware graph-based method targeted at ConvNets that aims at achieving efficient signal processing with reduced resource utilization. The second method addresses the challenge of determining the minimal precision arithmetic needed while preserving high accuracy. For this challenge, we propose variable-width dynamic fixed-point representations combined with a layer-by-layer design-space pruning heuristic across the different layers of the deep ConvNet model. The third method aims at achieving a modular design that can support different types of ConvNet layers while ensuring low resource utilization. For this challenge, we propose the modules to be relatively small and composed of computational filters that can be interconnected to build an entire accelerator design. These model elements can be easily configured through HDL parameters (e.g., layer type, mask size, stride, etc.) to meet the needs of specific ConvNet implementations and thus they can be reused to implement a wide variety of ConvNet architectures. The fourth method addresses the challenge of design portability between two different FPGA vendor platforms, namely, Intel/Altera and Xilinx. For this challenge, we propose to instantiate the device-specific hardware blocks needed in each computational filter, rather than relying on the synthesis tools to infer these blocks, while keeping track of the similarities and differences between the two platforms. We believe that the solutions to these design challenges further advance knowledge as they can benefit designers and other researchers using similar devices or facing similar challenges. Our results demonstrated the success of addressing the design challenges and achieving low (30%) resource utilization for the low-end FPGA platforms: Zedboard and Cyclone V. The design overcame the limitation of designs targeted for high-end platforms and that cannot fit on low-end IoT platforms. Furthermore, our design showed superior performance results (measured in terms of [Frame/s/W] per Dollar) compared to high-end optimized designs.

Multi-vendor standardized sequence for edited magnetic resonance spectroscopy

Spectral editing allows direct measurement of low-concentration metabolites, such as GABA, glutathione (GSH) and lactate (Lac), relevant for understanding brain (patho)physiology. The most widely used spectral editing technique is MEGA-PRESS, which has been diversely implemented across research sites and vendors, resulting in variations in the final resolved edited signal. In this paper, we describe an effort to develop a new universal MEGA-PRESS sequence with HERMES functionality for the major MR vendor platforms with standardized RF pulse shapes, durations, amplitudes and timings.New RF pulses were generated for the universal sequence. Phantom experiments were conducted on Philips, Siemens, GE and Canon 3 T MRI scanners using 32-channel head coils. In vivo experiments were performed on the same six subjects on Philips and Siemens scanners, and on two additional subjects, one on GE and one on Canon scanners. On each platform, edited MRS experiments were conducted with the vendor-native and universal MEGA-PRESS sequences for GABA (TE = 68 ms) and Lac editing (TE = 140 ms). Additionally, HERMES for GABA and GSH was performed using the universal sequence at TE = 80 ms.The universal sequence improves inter-vendor similarity of GABA-edited and Lac-edited MEGA-PRESS spectra. The universal HERMES sequence yields both GABA- and GSH-edited spectra with negligible levels of crosstalk on all four platforms, and with strong agreement among vendors for both edited spectra. In vivo GABA+/Cr, Lac/Cr and GSH/Cr ratios showed relatively low variation between scanners using the universal sequence.In conclusion, phantom and in vivo experiments demonstrate successful implementation of the universal sequence across all four major vendors, allowing editing of several metabolites across a range of TEs.