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Diffusion weighted MRI (DW-MRI) harmonization is necessary for multi-site or multi-acquisition studies. Current statistical methods address the need to harmonize from one site to another, but do not simultaneously consider the use of multiple datasets which are comprised of multiple sites, acquisitions protocols, and age demographics. This work explores deep learning methods which can generalize across these variations through semi-supervised and unsupervised learning while also learning to estimate multi-shell data from single-shell data using the Multi-shell Diffusion MRI Harmonization Challenge (MUSHAC) and Baltimore Longitudinal Study on Aging (BLSA) datasets. We compare disentanglement harmonization models, which seek to encode anatomy and acquisition in separate latent spaces, and a CycleGAN harmonization model, which uses generative adversarial networks (GAN) to perform style transfer between sites, to the baseline preprocessing and to SHORE interpolation. We find that the disentanglement models achieve superior performance in harmonizing all data while at the same transforming the input data to a single target space across several diffusion metrics (fractional anisotropy, mean diffusivity, mean kurtosis, primary eigenvector)., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Splenic artery pseudoaneurysms (PSA) are relatively rare but associated with high mortality/morbidity when presenting acutely. Embolization has emerged as the treatment of choice. We aim to evaluate the outcomes of embolization for the treatment of splenic artery PSAs., Methods: From 2007 to 2019, all patients that underwent embolization for splenic artery PSAs were included in this IRB-approved review. Evaluated outcomes included complications, morbidity/mortality rates, and 30-day white blood cell count. Student t-tests were performed to compare laboratory values before and after embolization. 5-year survival rates were estimated using Kaplan Meier methodology., Results: A retrospective analysis of 24 patients (14 males, mean age 51 ± 19 years) who underwent splenic artery PSA embolization was performed. Fifteen PSA embolizations were performed in an emergent setting. There was technical success in 23/24 patients. Etiologies included trauma (10), pancreatitis (9), post-surgical (3), and malignancy (2). Post-embolization patients had a mean length of stay of 19 days and within 30 days, 9 patients developed leukocytosis (median of 14,800/μl). The 5-year survival rate of these patients was 89% [95% CI 75% - 100%]. Post-procedure, 4 patients developed grade 2 complications. Grade 3 complications were observed in 5 patients. One (4.2%) splenic abscess was identified. Of the 19 patients with follow-up imaging, 14 patients had splenic infarcts (5 infarcts were >50% of splenic volume)., Conclusions: Splenic artery PSAs are encountered in the emergent setting and are most frequently secondary to trauma or pancreatitis. Embolization can be life-saving in these critically ill patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

A homozygous AAGGG repeat expansion within the RFC1 gene was recently described as a common cause of CANVAS syndrome. We examined 1069 sporadic ALS patients for the presence of this repeat expansion. We did not discover any carriers of the homozygous AAGGG expansion in our ALS cohort, indicating that this form of RFC1 repeat expansions is not a common cause of sporadic ALS. However, our study did identify a novel repeat conformation and further expanded on the highly polymorphic nature of the RFC1 locus., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background and Overview: Endodontics is a rewarding and challenging profession. The tasks of negotiating, cleaning, and shaping canals can frustrate even the most talented clinicians, particularly if the canals are blocked by calcifications. Circumventing these obstructions can be a slow, tedious process, and at times it is not possible. Various techniques have been developed to assist with this problem but have met with limited success. Given that the success of endodontic treatment is dependent on the elimination or reduction of bacterial influences on periapical tissues, this is a critical issue., Case Description: A new application of an existing technology is available. This technique uses 3-dimensional (3D) radiography (cone-beam computed tomography) and 3D intraoral imaging. Through the integration of the data sets, pathways are planned to locate blocked canals. Templates can be designed and fabricated on 3D printers that fit intimately on the dentition. Special drills are selected that fit through the sleeves embedded in the template. These pathways align the drill and guide the depth of the access. Once the canals are accessed, conventional root canal treatment is possible., Conclusions and Practical Implications: This case report reviews a new technique for treating a necrotic calcified root canal. The canal was identified in the apical one-third of the root. A pathway was planned to negotiate the canal using digital technology. The blockage was bypassed, and the root canal was successfully treated using a "template-guided access technique" with minimal tooth loss., (Copyright © 2021 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Objectives: Although several environmental factors contribute to the etiology of late-life depressive symptoms, the role of ambient air pollution has been understudied. Experimental data support the neurotoxicity of airborne particulate matter with aerodynamic diameter of ≤2.5 μm (PM 2.5 ), but it remains unclear whether long-term exposure is associated with late-life depressive symptoms. Our secondary aim was to explore whether the observed associations between exposure and depressive symptoms are explained by dementia risk., Design, Setting, and Participants: Prospective community-dwelling cohort study from the Women's Health Initiative Study of Cognitive Aging (1999-2010). Our analyses included 1,989 older women (baseline age 73.3 ± 3.75) with no prior depression or cognitive impairment., Measurements: Participants completed annual assessments of depressive symptoms (15-item Geriatric Depression Scale). Average ambient PM 2.5 exposure at the residential location was estimated by spatiotemporal modeling for the 3-years preceding each neuropsychological assessment. Participants underwent separate annual examinations for incident dementia defined by DSM-IV. Latent-class mixture models examined the association between PM 2.5 and identified trajectories of symptoms., Results: Six trajectories of depressive symptoms were identified. Across all women, PM 2.5 exposure was positively associated with depressive symptoms. The effect was especially strong in two clusters with sustained depressive symptoms (n = 625 sustained-mild [31%]; n = 125 sustained-moderate; [6%]). Among those with sustained-moderate symptoms, the estimated adverse effect of PM 2.5 exposure was greater than that of hypertension. Among women without dementia, associations were modestly attenuated., Conclusion: Long-term exposure to ambient fine particles was associated with increased depressive symptoms among older women without prior depression or cognitive impairment., (Copyright © 2019 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.)

Purpose: The diffusion MRI "b-vector" table describing the diffusion sensitization direction can be flipped and permuted in dimension due to different orientation conventions used in scanners and incorrect or improperly utilized file formats. This can lead to incorrect fiber orientation estimates and subsequent tractography failure. Here, we present an automated quality control procedure to detect when the b-table is flipped and/or permuted incorrectly., Methods: We define a "fiber coherence index" to describe how well fibers are connected to each other, and use it to automatically detect the correct configuration of b-vectors. We examined the performance on 3981 research subject scans (Baltimore Longitudinal Study of Aging), 1065 normal subject scans of high image quality (Human Connectome Project), and 202 patient scans (Vanderbilt University Medical Center), as well as 9 in-vivo and 9 ex-vivo animal data., Results: The coherence index resulted in a 99.9% (3979/3981) and 100% (1065/1065) success rate in normal subject scans, 98% (198/202) in patient scans, and 100% (18/18) in both in-vivo and ex-vivo animal data in detecting the correct gradient table in datasets without severe image artifacts. The four failing cases (4/202) in patient scans, and two failures in healthy subject scans (2/3981), all showed prominent motion or signal dropout artifacts., Conclusions: The fiber coherence measure can be used as an automatic quality assurance check in any diffusion analysis pipeline. Additionally, the success of this fiber coherence measure suggests potential broader applications, including evaluating data quality, or even providing diagnostic value as a biomarker of white matter integrity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Memory performance in older persons can reflect genetic influences on cognitive function and dementing processes. We aimed to identify genetic contributions to verbal declarative memory in a community setting., Methods: We conducted genome-wide association studies for paragraph or word list delayed recall in 19 cohorts from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, comprising 29,076 dementia- and stroke-free individuals of European descent, aged ≥45 years. Replication of suggestive associations (p < 5 × 10(-6)) was sought in 10,617 participants of European descent, 3811 African-Americans, and 1561 young adults., Results: rs4420638, near APOE, was associated with poorer delayed recall performance in discovery (p = 5.57 × 10(-10)) and replication cohorts (p = 5.65 × 10(-8)). This association was stronger for paragraph than word list delayed recall and in the oldest persons. Two associations with specific tests, in subsets of the total sample, reached genome-wide significance in combined analyses of discovery and replication (rs11074779 [HS3ST4], p = 3.11 × 10(-8), and rs6813517 [SPOCK3], p = 2.58 × 10(-8)) near genes involved in immune response. A genetic score combining 58 independent suggestive memory risk variants was associated with increasing Alzheimer disease pathology in 725 autopsy samples. Association of memory risk loci with gene expression in 138 human hippocampus samples showed cis-associations with WDR48 and CLDN5, both related to ubiquitin metabolism., Conclusions: This largest study to date exploring the genetics of memory function in ~40,000 older individuals revealed genome-wide associations and suggested an involvement of immune and ubiquitin pathways., (Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: There is a growing body of evidence attesting to the effectiveness and safety of selective non-operative management (SNOM) of abdominal gunshot wounds. However, much of the research which supports this conclusion has originated from a few centres, and the actual utilisation of SNOM by trauma surgeons is not known. We therefore conducted a survey to assess the acceptance of this strategy and evaluate variations in practise., Methods: Electronic questionnaire survey of trauma surgeons in the United States of America, Canada, Brazil, and South Africa. Responses were compared using Chi(2) and Fisher's exact tests., Results: 183 replies were received. 105 (57%) respondents practise SNOM of abdominal gunshot wounds, but there are marked regional variations in the acceptance of this strategy (p<0.01). Respondents who had completed trauma (p<0.01) or critical care (p<0.01) fellowships, and those who practise in a higher volume centre (defined as >50 penetrating abdominal injuries seen per year) (p<0.01) are more likely to practise SNOM of gunshot wounds. Most surgeons who practise SNOM regard peritonitis, omental and bowel evisceration, and being unable to evaluate a patient as a contraindication to attempting non-operative management. Almost all regard CT as essential. Respondents' preparedness to consider SNOM is related to injury extent., Conclusions: SNOM of abdominal gunshot wounds is practised by trauma surgeons in all four countries surveyed, but is not universally accepted, and there are variations in how it is practised., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: The role of neighborhood physical activity resources on childhood physical activity level is increasingly examined in pediatric obesity research. We describe how availability of physical activity resources varies by individual and block characteristics and then examine its associations with physical activity levels of Latino and black children in East Harlem, New York City., Methods: Physical activity resource availability by individual and block characteristics were assessed in 324 children. Availability was measured against 4 physical activity measures: average weekly hours of outdoor unscheduled physical activity, average weekly metabolic hours of scheduled physical activity, daily hours of sedentary behavior, and daily steps., Results: Physical activity resource availability differed by race/ethnicity, caregiver education, and income. Presence of one or more playgrounds on a child's block was positively associated with outdoor unscheduled physical activity (odds ratio [OR] = 1.95, 95% confidence interval [CI] 1.11-3.43). Presence of an after-school program on a child's block was associated with increased hours of scheduled physical activity (OR = 3.25, 95% CI 1.41-7.50) and decreased sedentary behavior (OR = 3.24, 95% CI 1.30-8.07). The more resources a child had available, the greater the level of outdoor unscheduled physical activity (P for linear trend = .026)., Conclusions: Neighborhood physical activity resource availability differs by demographic factors, potentially placing certain groups at risk for low physical activity level. Availability of select physical activity resources was associated with reported physical activity levels of East Harlem children but not with objective measures of physical activity., (Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Several popular classification algorithms used to segment magnetic resonance brain images assume that the image intensities, or log-transformed intensities, satisfy a finite Gaussian mixture model. In these methods, the parameters of the mixture model are estimated and the posterior probabilities for each tissue class are used directly as soft segmentations or combined to form a hard segmentation. It is suggested and shown in this paper that a Rician mixture model fits the observed data better than a Gaussian model. Accordingly, a Rician mixture model is formulated and used within an expectation maximization (EM) framework to yield a new tissue classification algorithm called Rician Classifier using EM (RiCE). It is shown using both simulated and real data that RiCE yields comparable or better performance to that of algorithms based on the finite Gaussian mixture model. As well, we show that RiCE yields more consistent segmentation results when used on images of the same individual acquired with different T1-weighted pulse sequences. Therefore, RiCE has the potential to stabilize segmentation results in brain studies involving heterogeneous acquisition sources as is typically found in both multi-center and longitudinal studies., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Time-dependent changes in brain activity were assessed in a group of older adults who maintained good physical and cognitive health at years 1, 3, 5, 7, and 9 of the Baltimore Longitudinal Study of Aging neuroimaging study. Each year, these participants underwent PET scans during rest and delayed verbal and figural recognition memory conditions. While memory performance remained stable over the 8 years, both generalized and modality-specific patterns of time-dependent changes in regional cerebral blood flow (rCBF) were found. Many brain regions showed steady, progressive changes in rCBF over the 8 years while others maintained rCBF for a number of years before showing incremental declines or increases in activity. These temporal patterns of change were observed in many regions of the brain, particularly in the frontal and temporal lobes, suggesting that there are distinctive patterns of age-related functional decline and compensatory activity over time. The precise patterns of regional involvement and the temporal dynamics of rCBF change within specific regions vary based on cognitive processing demands.

Changes in brain activity over time were evaluated in a group of older adults in the Baltimore Longitudinal Study of Aging who maintained good physical and cognitive health. Participants underwent PET scans during rest and delayed verbal and figural recognition memory performance at year 1 baseline and at year 9. While memory performance remained stable over the 8 years, longitudinal changes in regional cerebral blood flow were observed within each scan condition. Further analyses revealed distinctive patterns of change related specifically to verbal or figural recognition, as well as longitudinal changes common to all scan conditions. These findings demonstrate that the older brain undergoes functional reorganization with increasing age in healthy, cognitively stable individuals. In view of the stable memory performance, the task-dependent results suggest that age-related changes in brain activity help maintain cognitive function with advancing age.

Positron emission tomography (PET) patterns of cerebral blood flow associated with verbal and figural memory are described in relation to their value as functional probes for studying longitudinal changes that occur in the aging brain. Relative to a matching control task, verbal and figural encoding increase blood flow in prefrontal cortex (PFC), anterior cingulate, insular, lateral and medial temporal, occipital cortex and the cerebellum. Additionally, medial temporal regions exhibited greater activity during figural encoding relative to verbal encoding. During recognition, blood flow increases in prefrontal, cingulate, insular, and lateral temporal and Broca's areas. Analysis of hemispheric asymmetry reveals that the prefrontal cortex exhibits regionally dependent results. Prefrontal region BA 10 demonstrates more bilateral activation during encoding and retrieval, whereas BA 46 shows right greater than left activation during both encoding and retrieval. Overall, the two tasks activate diverse regions within the frontal, temporal and occipital lobes of the brain, including areas that show age-related structural changes, proving their usefulness in the longitudinal assessment of brain function in the elderly.

The use of virtual environment (VE) technology to assess spatial navigation in humans has become increasingly common and provides an opportunity to quantify age-related deficits in human spatial navigation and promote a comparative approach to the neuroscience of cognitive aging. The purpose of the present study was to assess age differences in navigational behavior in a VE and to examine the relationship between this navigational measure and other more traditional measures of cognitive aging. Following pre-training, participants were confronted with a VE spatial learning task and completed a battery of cognitive tests. The VE consisted of a richly textured series of interconnected hallways, some leading to dead ends and others leading to a designated goal location in the environment. Compared to younger participants, older volunteers took longer to solve each trial, traversed a longer distance, and made significantly more spatial memory errors. After 5 learning trials, 86% of young and 24% of elderly volunteers were able to locate the goal without error. Performance on the VE navigation task was positively correlated with measures of mental rotation and verbal and visual memory.

Observational studies suggest that estrogen replacement therapy (ERT) may protect against age-related memory decline and lower the risk of Alzheimer's disease (AD). This study aimed to characterize the neural substrates of those effects by comparing 2-year longitudinal changes in regional cerebral blood flow (rCBF) in 12 ERT users and 16 nonusers. Positron emission tomography (PET) measurements of rCBF were obtained under three conditions: rest, and verbal and figural recognition memory tasks. Groups showed different patterns of change in rCBF over time in a number of brain areas. These group differences, for the most part, reflected regions of increased rCBF over time in users compared to nonusers. The greatest differences between ERT users and nonusers were in the hippocampus, parahippocampal gyrus, and temporal lobe, regions that form a memory circuit and that are sensitive to preclinical AD. Across a battery of standardized neuropsychological tests of memory, users obtained higher scores than did nonusers of comparable intellect. Group differences in longitudinal change in rCBF patterns may reflect one way through which hormones modulate brain activity and contribute to enhanced memory performance among ERT users.