Absolute Volume Research Articles

Supra-renal aortic atheroma extent and composition predict acute kidney injury after transcatheter aortic valve replacement: A three-dimensional computed tomography study

ObjectiveAcute kidney injury (AKI) may complicate transcatheter aortic valve replacement (TAVR) and could be linked to atheroembolization associated with catheter manipulation in the supra-renal (SR) aorta.We sought to determine the impact of SR aortic atheroma burden (SR-AAB) and composition, as well as of the aortic valve calcium score (AV-CS), measured at pre-operative multislice computed tomography (PO-MSCT), on AKI-TAVR. MethodsAll TAVR-patients 3 January-2018 to December-2020 were included. A three-dimensional analysis of PO-MSCT was performed, calculating percentage SR-AAB (%SR-AAB) as [(absolute SR-AAB volume)*100/vessel volume]. Types of plaque were defined according to Hounsfield unit (HU) intensity ranges. Calcified plaque was subcategorized into 3 strata: low- (351–700 HU), mid- (701–1000 HU), and high‑calcium (>1000 HU, termed 1 K-plaque). ResultsThe study population included 222 patients [mean age 83.3 ± 5.7 years, 95 (42.8%) males], AKI-TAVR occurred in 67/222 (30.2%). Absolute SR-AAB (41.3 ± 16.4 cm3 vs. 32.5 ± 10.7 cm3,p < 0.001) and %SR-AAB (17.6 ± 5.1% vs. 13.9 ± 4.3%,p < 0.001) were significantly higher in patients developing AKI-TAVR.Patients who developed AKI-TAVR had higher mid‑calcium (6.9 ± 3.8% vs. 4.2 ± 3.5%,p < 0.001) and 1 K-plaque (5.4 ± 3.7% vs. 2.4 ± 2.4%,p < 0.001) with no difference in AV-CS (p = 0.691).Adjusted multivariable logistic regression analysis showed that %SR-AAB [OR (x%increase): 1.12, 95%CI: 1.04–1.22,p = 0.006] and %SR-calcified plaque [OR (x%increase): 5.60, 95%CI: 2.50–13.36,p < 0.001] were associated with AKI-TAVR. Finally, 3-knots spline analyses identified %SR-AAB >15.0% and %SR-calcified plaque >7.0% as optimal thresholds to predict an increased risk of AKI-TAVR. ConclusionsSuprarenal aortic atheroma, when highly calcified, is associated with AKI-TAVR. Perioperative-MSCT assessment of aortic atherosclerosis may help in identification of patients at high-risk for AKI-TAVR, who could benefit from higher peri-operative surveillance.

Google Trends for health research: Its advantages, application, methodological considerations, and limitations in psychiatric and mental health infodemiology.

The high utilization of infodemiological tools for psychiatric and mental health topics signals the emergence of a new discipline. Drawing on the definition of infodemiology by Eysenbach, this emerging field can be termed "psychiatric and mental health infodemiology," defined as the science of distribution and determinants of information in an electronic medium, including the internet, or in a population to inform mental health services and policies. Since Google Trends is one of its popular tools, this minireview describes its advantages, application, methodological considerations, and limitations in psychiatric and mental health research. The advantage of Google Trends is the nature of its data, which may represent the actual behavior rather than their users' stated preferences in real-time through automatic anonymization. As such, it can provide readily available data about sensitive health topics like mental disorders. Therefore, Google Trends has been used to explore public concerns, interests, and behaviors about psychiatric and mental health phenomena, service providers, and specific disciplines. In this regard, several methodological can be considered by studies using Google Trends, including documenting their exact keywords, query category, time range, location, and date of retrieval. Likewise, its limitations should be accounted for in its interpretation, including restricted representation of people who use the Google search engine, limited validity in areas with low internet penetration or freedom of speech, does not provide absolute search volumes, unknown sampled queries, and limited transparency in its algorithm, especially the terms and idioms it subsumes under its "topic" keywords.

A Novel Frameless Laser Stereotaxis System for Neurosurgical Interventions

The aim of the article is to introduce a novel laser-based frameless stereotactic device that can locate intracranial lesions quickly and with computed tomograph (CT)/magnetic resonance imaging (MRI) films. Preliminary experiences of application in 416 cases are also summarized. From August in 2020 to October in 2022, a total of 416 cases of new minimalist laser stereotactic surgery have been performed on 415 patients. Of the 415 patients, 377 had intracranial hematomas, while the remaining cases were brain tumors or brain abscesses. Postoperative CT was used to evaluate the accuracy of catheterization of 405 patients according to the MISTIE study. The duration time of locating was recorded. Rebleeding refers to the definition: Compared with preoperative CT, the relative volume of postoperative hematoma increases by >33% or absolute volume increase >12.5 mL. According to postoperative CT, the accuracy of 405 stereotactic catheterization cases was good in 346 cases (85.4%) and suboptimal in 59 cases (14.6%), with no poor results. Postoperative rebleeding occurred in 4 spontaneous cerebral hemorrhage cases and 1 brain biopsy case. The average localization time of supratentorial lesions was 13.2 minutes in the supine position, 21.5 minutes in the lateral position, and 27.6 minutes in the prone position. The new laser-based frameless stereotactic device is simple in principle and convenient in positioning operation of brain hematoma and abscess puncture, brain biopsy and tumor surgery, and appropriate to the precision requirements in most craniocerebral surgery.

Longitudinal development of the cerebellum in human infants during the first 800 days

Revealing early dynamic development of the normative cerebellar structures contributes to exploring cerebellum-related neurodevelopmental disorders. Here, leveraging infant-tailored cerebellar image processing techniques, we studied the dynamic volumetric developmental trajectories of cerebellum and 27 cerebellar sub-regions and their relationships with behavioral scores based on 511 high-resolution structural MRI scans during the first 800 postnatal days. The ratio of the entire cerebellum to the intracranial volume increases rapidly at first and then peaks at 13months after birth. Both the absolute and relative volumes of most cerebellar sub-structures exhibit rapid increase at first, then the relative volumes decrease slightly after arriving at peaks (except for X lobules). Each lobule depicts larger absolute volume in males than in females. The within-subject variation of the cerebellar volumetric percentile score is generally stable. The volumetric development of several lobules (e.g., V, Crus I, and Crus II) has a significantly positive correlation with fine motor skills during the age range examined.

Quantitative Assessment of Lung Volumes and Enhancement in Patients with COVID-19: Role of Dual-Energy CT

Dual-energy computed tomography (DECT) has been used for detecting pulmonary embolism, but the role of lung perfusion DECT as a predictor of prognosis of coronavirus disease 2019 (COVID-19) has not been defined yet. The aim of our study was to explore whether the enhancement pattern in COVID-19+ patients relates to the disease outcome. A secondary aim was to compare the lung volumes in two subgroups of patients. In this observational study, we considered all consecutive COVID-19+ patients who presented to the emergency room between January 2021 and December 2021 with respiratory symptoms (with mild to absent lung consolidation) and were studied by chest contrast-enhanced DECT to be eligible. Two experienced radiologists post-processed the images using the "lung-analysis" software (SyngoVia). Absolute and relative enhancement lung volumes were assessed. Patients were stratified in two subgroups depending on clinical outcome at 30 days: (i) good outcome (i.e., discharge, absence of clinical or imaging signs of disease); (ii) bad outcome (i.e., hospitalization, death). Patient sub-groups were compared using chi-square test or Fisher test for qualitative parameters, chi-square test or Spearman's Rho test for quantitative parameters, Students' t-test for parametric variables and Wilcoxon test for non-parametric variables. We enrolled 78 patients (45M), of whom, 16.7% had good outcomes. We did not observe any significant differences between the two groups, both in terms of the total enhancement evaluation (p = 0.679) and of the relative enhancement (p = 0.918). In contrast, the average lung volume of good outcome patients (mean value of 4262 mL) was significantly larger than that of bad outcome patients (mean value of 3577.8 mL), p = 0.0116. All COVID-19+ patients, with either good or bad outcomes, presented similar enhancement parameters and relative enhancements, underlining no differences in lung perfusion. Conversely, a significant drop in lung volume was identified in the bad outcome subgroup eligible compared to the good outcome subgroup.

Detection of Diclofenac-Induced Alterations in Rainbow Trout (Oncorhynchus mykiss) Using Quantitative Stereological Methods.

In 2013, the nonsteroidal anti-inflammatory drug diclofenac (DCF) was included in the watch list for emerging pollutants under the European Union Water Framework Directive. Frequently, monitoring data revealed DCF concentrations in surface waters exceeding the proposed environmental quality standards of 0.04 µg L-1 and 0.126 µg L-1 . In recent literature, the possible effects of DCF on fish are discussed controversially. To contribute to a realistic risk assessment of DCF, a 28-day exposure experiment was carried on rainbow trout (Oncorhynchus mykiss). To warrant reliability of data, experiments were conducted considering the Criteria for Reporting and Evaluating Ecotoxicity Data. The test concentrations of DCF used (0.1, 0.5, 1, 5, 25, and 100 µg L-1 ) also included environmentally relevant concentrations. The lowest-observed-effect concentration (LOEC) for a significant decrease in the plasma concentrations of the DCF biomarker prostaglandin E2 was 0.5 µg L-1 (male fish). For objective evaluation of relevant histomorphological parameters of gills and trunk kidneys, unbiased quantitative stereological methods were applied. In the gills, significant increases in the thickness of the secondary lamella and in the true harmonic mean of barrier thickness in secondary lamellae were present at DCF concentrations of 25 µg L-1 and 100 µg L-1 . In the trunk kidneys, the absolute and relative volumes of nephrons were significantly decreased, paralleled by a significant increase of the volume of the interstitial renal tissue. With regard to quantitative histomorphological alterations in the trunk kidney, the observed LOEC was 0.5 µg L-1 . The quantitative histomorphological analyses that were conducted allow identification and objective quantification of even subtle but significant morphological effects and thus provide an important contribution for the comparability of study results for the determination of no-observed-effect concentrations(NOEC). Environ Toxicol Chem 2023;42:859-872. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Deformable image registration based on single or multi-atlas methods for automatic muscle segmentation and the generation of augmented imaging datasets.

Muscle segmentation is a process relied upon to gather medical image-based muscle characterisation, useful in directly assessing muscle volume and geometry, that can be used as inputs to musculoskeletal modelling pipelines. Manual or semi-automatic techniques are typically employed to segment the muscles and quantify their properties, but they require significant manual labour and incur operator repeatability issues. In this study an automatic process is presented, aiming to segment all lower limb muscles from Magnetic Resonance (MR) imaging data simultaneously using three-dimensional (3D) deformable image registration (single inputs or multi-atlas). Twenty-three of the major lower limb skeletal muscles were segmented from five subjects, with an average Dice similarity coefficient of 0.72, and average absolute relative volume error (RVE) of 12.7% (average relative volume error of -2.2%) considering the optimal subject combinations. The multi-atlas approach showed slightly better accuracy (average DSC: 0.73; average RVE: 1.67%). Segmented MR imaging datasets of the lower limb are not widely available in the literature, limiting the potential of new, probabilistic methods such as deep learning to be used in the context of muscle segmentation. In this work, Non-linear deformable image registration is used to generate 69 manually checked, segmented, 3D, artificial datasets, allowing access for future studies to use these new methods, with a large amount of reliable reference data.

Neural network-derived perfusion maps: A model-free approach to computed tomography perfusion in patients with acute ischemic stroke.

In this study, we investigate whether a Convolutional Neural Network (CNN) can generate informative parametric maps from the pre-processed CT perfusion data in patients with acute ischemic stroke in a clinical setting. The CNN training was performed on a subset of 100 pre-processed perfusion CT dataset, while 15 samples were kept for testing. All the data used for the training/testing of the network and for generating ground truth (GT) maps, using a state-of-the-art deconvolution algorithm, were previously pre-processed using a pipeline for motion correction and filtering. Threefold cross validation had been used to estimate the performance of the model on unseen data, reporting Mean Squared Error (MSE). Maps accuracy had been checked through manual segmentation of infarct core and total hypo-perfused regions on both CNN-derived and GT maps. Concordance among segmented lesions was assessed using the Dice Similarity Coefficient (DSC). Correlation and agreement among different perfusion analysis methods were evaluated using mean absolute volume differences, Pearson correlation coefficients, Bland-Altman analysis, and coefficient of repeatability across lesion volumes. The MSE was very low for two out of three maps, and low in the remaining map, showing good generalizability. Mean Dice scores from two different raters and the GT maps ranged from 0.80 to 0.87. Inter-rater concordance was high, and a strong correlation was found between lesion volumes of CNN maps and GT maps (0.99, 0.98, respectively). The agreement between our CNN-based perfusion maps and the state-of-the-art deconvolution-algorithm perfusion analysis maps, highlights the potential of machine learning methods applied to perfusion analysis. CNN approaches can reduce the volume of data required by deconvolution algorithms to estimate the ischemic core, and thus might allow the development of novel perfusion protocols with lower radiation dose deployed to the patient.

Trade-driven changes in China's air pollutant emissions during 2012–2017

Trade plays an important role in driving regional production and the associated pollutant emissions. Revealing the patterns and underlying driving forces of trade may be critical for informing future mitigation actions among regions and sectors. In this study, we focused on the “Clean Air Action” period from 2012 to 2017 and revealed the changes and driving forces in trade-related air pollutant emissions (including sulfur dioxide (SO2), particulate matter with a diameter equal to or less than 2.5 μm (PM2.5), nitrogen oxides (NOx), volatile organic compound (VOC), and carbon dioxide (CO2)) among regions and sectors in China. Our results showed that emissions embodied in domestic trade decreased considerably in absolute volume nationwide (23–61 %, except for VOC and CO2), but the relative contribution ratios from consumption in central and southwestern China increased (from 13 to 23 % to 15–25 % for various species), and those for eastern China decreased (from 39 to 45 % to 33–41 % for various species). From the sector perspective, trade-driven emissions from the power sector decreased in relative contribution ratios, while those from other sectors (including chemical, metal, nonmetal and services) were outstanding for specific regions, and became new targeted sectors when seeking mitigation through domestic supply chains. For changes in trade-related emissions, reduction in emission factor dominated the decreasing trends for almost all regions (27–64 % for the national total, except for VOC and CO2), and optimization in trade and/or energy structures also played marked reduction roles in specific regions, far offsetting the increasing effect of increasing trade volume (26–32 %, except for VOC and CO2). Our study provides a comprehensive picture of how trade-associated pollutant emissions changed during the “Clean Air Action” period, which may facilitate the formulation of more effective trade-associated policies to mitigate future emissions.

Evaluation of the Efficiency of Neuronavigation in Patients with Glioblastoma

Objective: To investigate the effect of neuronavigation use on mortality in patients with glioblastoma. Methods: For each of the 26 patients that underwent neuronavigation-assisted supratotal resection for glioblastoma between 2018 and 2020, one patient that underwent supratotal resection without navigation was selected. Results: Radiographic radicality was observed in 35% of the cases in the neuronavigation-assisted surgery group and 29% of those in the conventional surgery group. Absolute and relative residual tumor volumes were significantly lower in the neuronavigation-assisted surgery group. Radical tumor resection was associated with a very significant increase in survival. There was no significant difference in the survival rates between the patients that underwent surgery with and without neuronavigation. This was attributed to the small number of participants and supratotal resection being performed in all statistically determined patients The low median survival period of glioblastoma may have also contributed to this finding. Conclusions: Surgery plays an important role in the treatment of glioblastoma. A combination of techniques including intraoperative magnetic resonance imaging, neuronavigation, ultrasound, and fluorescence guidance allows for safe and maximum surgical resection, leading to better outcomes in terms of survival and postoperative functional recovery. However, despite maximal surgical resection and adjuvant chemotherapy-radiotherapy, most cases develop tumor recurrence within 10 months, which is considered to be due to established cancer stem cells. Therefore, there is an urgent need to develop more effective treatment strategies for glioblastoma.

Analysis of the effect of using Covid-19 medical mask waste with polypropylene on the compressive strength and split tensile strength of high-performance concrete

The coronavirus causing the Covid-19 pandemic has been experienced by us since 2020, which has led to an increase in the use of disposable medical masks in Indonesia and even worldwide. Polypropylene is a thermoplastic polymer used as the main ingredient in medical masks that takes more than 25 years to decompose in landfills. This research offers an innovative way to use medical mask waste in high-performance concrete. The resulting medical mask waste is subjected to a sterilization process and cut into fibers to analyze the effect of its addition on the compressive strength and splitting tensile strength of high-performance concrete. The research began with testing the physical and mechanical properties of the materials, designing a concrete mix using the absolute volume method, and taking samples for compression and splitting tests. The variation in the ratio of water-cement and pozzolanic materials w/(c+p) is 0.32. As a result, the compressive strength of concrete increased with a fiber size of 5×0.5 cm and 2×0.5 cm. An increase is up to 7 % with an optimum value of 72.37 MPa with a fiber size of 2×0.5 cm and a content of 0.15 %. However, there was a decrease in the compressive strength with a 5×1 cm mask fiber size. The overall split tensile strength value of all variations in waste fiber size and content increased with an optimum value of 7.29 MPa at 0.20 % fiber content with a fiber size of 5×0.5 cm. This indicates that polypropylene fibers from medical mask waste have a positive effect on high-performance concrete, namely improve the properties of concrete with a low tensile strength, which is expected to inhibit the propagation and reduce the size of cracks in reinforced concrete structures

Alternative methods to measure breast density in younger women

BackgroundBreast density is a strong and potentially modifiable breast cancer risk factor. Almost everything we know about breast density has been derived from mammography, and therefore, very little is known about breast density in younger women aged <40. This study examines the acceptability and performance of two alternative breast density measures, Optical Breast Spectroscopy (OBS) and Dual X-ray Absorptiometry (DXA), in women aged 18–40.MethodsBreast tissue composition (percent water, collagen, and lipid content) was measured in 539 women aged 18–40 using OBS. For a subset of 169 women, breast density was also measured via DXA (percent fibroglandular dense volume (%FGV), absolute dense volume (FGV), and non-dense volume (NFGV)). Acceptability of the measurement procedures was assessed using an adapted validated questionnaire. Performance was assessed by examining the correlation and agreement between the measures and their associations with known determinants of mammographic breast density.ResultsOver 93% of participants deemed OBS and DXA to be acceptable. The correlation between OBS-%water + collagen and %FGV was 0.48. Age and BMI were inversely associated with OBS-%water + collagen and %FGV and positively associated with OBS-%lipid and NFGV.ConclusionsOBS and DXA provide acceptable and viable alternative methods to measure breast density in younger women aged 18–40 years.

Noncontrast MRI in assessing venous reflux of legs using QFlow analysis and radial basis function neural network technique

Since venous reflux is difficult to quantify, triggered angiography non-contrast-enhanced (TRANCE)-magnetic resonance imaging (MRI) is a novel tool for objectively evaluating venous diseases in the lower extremities without using contrast media. This study included 26 pre-intervention patients with superficial venous reflux in the lower extremities and 15 healthy volunteers. The quantitative flow (QFlow) analyzed the phase shift information from the pixels within the region of interest from MRI. The fast and simple radial basis function neural network (RBFNN) learning model is constructed by determining the parameters of the radial basis function and the weights of the neural network. The input parameters were the variables generated through QFlow, while the output variables were morbid limbs with venous reflux and normal limb classification. The stroke volume, forward flow volume, absolute stroke volume, mean flux, stroke distance, and mean velocity of greater saphenous veins from QFlow analysis could be used to discriminate the morbid limbs of pre-intervention patients and normal limbs of healthy controls. The neural network successfully classified the morbid and normal limbs with an accuracy of 90.24% in the training stage. The classification of venous reflux using the RBFNN model may assist physicians in clinical settings.

A prospective, randomized, single-blind study to compare two methods of treating cystic lesions in the jaw

The study aimed to assess the usefulness of a bovine bone substitute material in treating cystic lesions in the jaw with a maximum diameter of <4 cm. In this prospective, randomized, single-blind intervention study of 116 patients, 61 underwent cystectomy with a subsequent filling of the defect using a bovine xenograft, and 55 underwent cystectomy alone. Volumetric measurement of the cysts was performed preoperatively and 6 and 12 months postoperatively using the available digital volume tomography data sets. Follow-up appointments were made 14 days and 1, 3, 6, and 12 months postoperatively. Almost complete regeneration was seen in both treatment groups within 12 months, with no significant difference in absolute volume loss between the 2 groups (P=.521). Examination 14 days after surgery revealed a tendency for more wound healing disorders with the use of a bone substitute (P=.077). It was no longer possible to detect any further differences in later examinations. Using bovine bone substitute material has no radiologically measurable advantage over cystectomy alone without defect filling regarding bone regeneration. In addition, there was a tendency for more wound-healing disorders to occur in the bone substitute group.

The association between perihaematomal oedema and functional outcome after spontaneous intracerebral haemorrhage: A systematic review and meta-analysis.

Perihaematomal oedema (PHO) formation has gained increasing interest as a therapeutic target after spontaneous intracerebral haemorrhage (ICH). Whether PHO contributes to poor outcome is unclear. We aimed to determine the association between PHO and outcome in patients with spontaneous ICH. We searched five databases up to 17 November 2021 for studies of ⩾10 adults with ICH reporting the presence of PHO and outcome. We assessed risk of bias, extracted aggregate data and used random effects meta-analysis to pool studies that reported odds ratios (OR) with 95% confidence intervals (CI). Primary outcome was poor functional outcome defined as modified Rankin Scale score of 3-6 at 3 months. Additionally, we assessed PHO growth and poor outcome at any time of follow-up. We prospectively registered the protocol in PROSPERO (CRD42020157088). We identified 12,968 articles, of which we included 27 studies (n = 9534). Eighteen studies reported an association between larger PHO volume and poor outcome, six a neutral result and three an inverse relationship. Larger absolute PHO volume was associated with poor functional outcome at 3 months (OR per mL increase of absolute PHO 1.03, 95% CI 1.00-1.06, I2 44%, four studies). Additionally, PHO growth was associated with poor outcome (OR 1.04, 95% CI 1.02-1.06, I2 0%, seven studies). In patients with spontaneous ICH, larger PHO volume is associated with poor functional outcome at 3 months. These findings support the development and investigation of new therapeutic interventions targeting PHO formation to evaluate if reduction of PHO improves outcome after ICH.

Validity Assessment of an Automated Brain Morphometry Tool for Patients with De Novo Memory Symptoms.

Automated volumetric analysis of structural MR imaging allows quantitative assessment of brain atrophy in neurodegenerative disorders. We compared the brain segmentation performance of the AI-Rad Companion brain MR imaging software against an in-house FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline. T1-weighted images of 45 participants with de novo memory symptoms were selected from the OASIS-4 database and analyzed through the AI-Rad Companion brain MR imaging tool and the FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline. Correlation, agreement, and consistency between the 2 tools were compared among the absolute, normalized, and standardized volumes. Final reports generated by each tool were used to compare the rates of detection of abnormality and the compatibility of radiologic impressions made using each tool, compared with the clinical diagnoses. We observed strong correlation, moderate consistency, and poor agreement between absolute volumes of the main cortical lobes and subcortical structures measured by the AI-Rad Companion brain MR imaging tool compared with FreeSurfer. The strength of the correlations increased after normalizing the measurements to the total intracranial volume. Standardized measurements differed significantly between the 2 tools, likely owing to differences in the normative data sets used to calibrate each tool. When considering the FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline as a reference standard, the AI-Rad Companion brain MR imaging tool had a specificity of 90.6%-100% and a sensitivity of 64.3%-100% in detecting volumetric abnormalities. There was no difference between the rate of compatibility of radiologic and clinical impressions when using the 2 tools. The AI-Rad Companion brain MR imaging tool reliably detects atrophy in cortical and subcortical regions implicated in the differential diagnosis of dementia.

Individually adjusted absolute blood volume feedback control: A promising solution for intradialytic hypotension.

Intradialytic hypotension (IDH) remains one of the most frequent complications associated to hemodialysis (HD), frequently triggered by a reduction in absolute blood volume (ABV) not compensated by vascular refilling. A recently developed dilutional method allows routinary measurement of ABV and, by a simple algorithm, may turn blood volume monitor (BVM) guided UF (ultrafiltration) biofeedback into an ABV control, automatically adjusting UF rate to maintain ABV above a preset threshold. The aim of this study is to identify an individual critical ABV threshold and test the ability of an ABV feedback control to avoid IDH. We studied 24 patients throughout three consecutive midweek HD treatments. ABV and blood pressure (BP) were measured every 30 min and anytime the patient referred any symptoms to identify each patient's critical ABV (ABV at the time of hypotension). A fixed bolus dilution approach at the start of HD was used to calculate ABV. Then, patients were followed through three additional HD treatments and IDH development was analyzed. Seventy-one treatments performed in 24 patients. ABV monitoring showed a constant decrease as HD treatment progressed. Thirteen IDH events were observed in eight different patients, with a mean systolic BP drop in IDH treatments of 37.38 ± 4.31 mmHg and a mean adjusted ABV at hypotension of 71.07 ± 14.88mL/kg. Critical ABV was individually set in patients prone to IDH. As expected, ABV feedback control successfully maintained ABV over preset critical ABV. IDH events were avoided in 21 out of 22 treatments performed. ABV drop was successfully reduced, as well as SBP drop (despite similar UF than prior to ABV feedback control implementation). ABV feedback control avoided IDH in 21 out of 22 treatments performed by maintaining blood volume above critical ABV, significantly reducing ABV variations without compromising prescribed UF.

Comparison of automated segmentation techniques for magnetic resonance images of the prostate

BackgroundContouring of anatomical regions is a crucial step in the medical workflow and is both time-consuming and prone to intra- and inter-observer variability. This study compares different strategies for automatic segmentation of the prostate in T2-weighted MRIs.MethodsThis study included 100 patients diagnosed with prostate adenocarcinoma who had undergone multi-parametric MRI and prostatectomy. From the T2-weighted MR images, ground truth segmentation masks were established by consensus from two expert radiologists. The prostate was then automatically contoured with six different methods: (1) a multi-atlas algorithm, (2) a proprietary algorithm in the Syngo.Via medical imaging software, and four deep learning models: (3) a V-net trained from scratch, (4) a pre-trained 2D U-net, (5) a GAN extension of the 2D U-net, and (6) a segmentation-adapted EfficientDet architecture. The resulting segmentations were compared and scored against the ground truth masks with one 70/30 and one 50/50 train/test data split. We also analyzed the association between segmentation performance and clinical variables.ResultsThe best performing method was the adapted EfficientDet (model 6), achieving a mean Dice coefficient of 0.914, a mean absolute volume difference of 5.9%, a mean surface distance (MSD) of 1.93 pixels, and a mean 95th percentile Hausdorff distance of 3.77 pixels. The deep learning models were less prone to serious errors (0.854 minimum Dice and 4.02 maximum MSD), and no significant relationship was found between segmentation performance and clinical variables.ConclusionsDeep learning-based segmentation techniques can consistently achieve Dice coefficients of 0.9 or above with as few as 50 training patients, regardless of architectural archetype. The atlas-based and Syngo.via methods found in commercial clinical software performed significantly worse (0.855-0.887 Dice).

The subcortical correlates of autistic traits in school-age children: a population-based neuroimaging study

BackgroundThere is emerging evidence that the neuroanatomy of autism forms a spectrum which extends into the general population. However, whilst several studies have identified cortical morphology correlates of autistic traits, it is not established whether morphological differences are present in the subcortical structures of the brain. Additionally, it is not clear to what extent previously reported structural associations may be confounded by co-occurring psychopathology. To address these questions, we utilised neuroimaging data from the Adolescent Brain Cognitive Development Study to assess whether a measure of autistic traits was associated with differences in child subcortical morphology, and if any observed differences persisted after adjustment for child internalising and externalising symptoms.MethodsOur analyses included data from 7005 children aged 9–10 years (female: 47.19%) participating in the Adolescent Brain Cognitive Development Study. Autistic traits were assessed using scores from the Social Responsiveness Scale (SRS). Volumes of subcortical regions of interest were derived from structural magnetic resonance imaging data.ResultsOverall, we did not find strong evidence for an association of autistic traits with differences in subcortical morphology in this sample of school-aged children. Whilst lower absolute volumes of the nucleus accumbens and putamen were associated with higher scores of autistic traits, these differences did not persist once a global measure of brain size was accounted for.LimitationsIt is important to note that autistic traits were assessed using the SRS, of which higher scores are associated with general behavioural problems, and therefore may not be wholly indicative of autism-specific symptoms. In addition, individuals with a moderate or severe autism diagnosis were excluded from the ABCD study, and thus, the average level of autistic traits will be lower than in the general population which may bias findings towards the null.ConclusionsThese findings from our well-powered study suggest that other metrics of brain morphology, such as cortical morphology or shape-based phenotypes, may be stronger candidates to prioritise when attempting to identify robust neuromarkers of autistic traits.

The deep trabecular structure of first metacarpals in extant hominids.

Recent studies have associated subarticular trabecular bone distribution in the extant hominid first metacarpal (Mc1) with observed thumb use, to infer fossil hominin thumb use. Here, we analyze the entire Mc1 to test for interspecific differences in: (1) the absolute volume of trabecular volume fraction, (2) the distribution of the deeper trabecular network, and (3) the distribution of trabeculae in the medullary cavity, especially beneath the Mc1 disto-radial flange. Trabecular bone was imaged using micro-computed tomography in a sample of Homo sapiens (n= 11), Pan paniscus (n= 10), Pan troglodytes (n= 11), Gorilla gorilla (n= 10) and Pongo sp., (n= 7). Using Canonical Holistic Morphometric Analysis (cHMA), we tested for interspecific differences in the trabecular bone volume fraction (BV/TV) and its relative distribution (rBV/TV) throughout the Mc1, including within the head, medullary cavity, and base. P. paniscus had the highest, and H. sapiens the lowest, BV/TV relative to other species. rBV/TV distribution statistically distinguished the radial concentrations and lack of medullary trabecular bone in the H. sapiens Mc1 from all other hominids. H. sapiens and, to a lesser extent, G. gorilla also had a significantly higher trabecular volume beneath the disto-radial flange relative to other hominids. These results are consistent with differences in observed thumb use in these species and may also reflect systemic differences in bone volume fraction. The trabecular bone extension into the medullary cavity and concentrations beneath the disto-radial flange may represent crucial biomechanical signals that will aid in the inference of fossil hominin thumb use.