Correlates of life course physical activity in participants of the Baltimore longitudinal study of aging

Physical activity is consistently associated with better health and longer life spans. However, the extent to which length and intensity of exercise across the life course impact health outcomes relative to current activity is undefined. Participants of the Baltimore Longitudinal Study of Aging were asked to categorize their level of physical activity in each decade of life from adolescence to the current decade. In linear mixed effects models, self-reported past levels of physical activity were significantly associated with activity assessed at study visits in the corresponding decade of life either by questionnaire or accelerometry. A pattern of life course physical activity (LCPA) derived by ranking participants on reported activity intensity across multiple decades was consistent with the trajectories of activity estimated from standard physical activity questionnaires assessed at prior study visits. In multivariable linear regression models LCPA was associated with clinical characteristics, measures of body composition and indicators of physical performance independent of current physical activity. After adjustment for minutes of high intensity exercise, LCPA remained significantly associated with peak VO2, fasting glucose, thigh muscle area and density, abdominal subcutaneous fat, usual gait speed, lower extremity performance, and multimorbidity (all p < 0.01) at the index visit. The observed associations suggest that an estimate of physical activity across decades provides complementary information to information on current activity and reemphasizes the importance of consistently engaging in physical activity over the life course.

Comprehensive behavioral and physiologic assessment of peripheral and central auditory function in individuals with mild traumatic brain injury

Auditory complaints are frequently reported by individuals with mild traumatic brain injury (mTBI) yet remain difficult to detect in the absence of clinically significant hearing loss. This highlights a growing need to identify sensitive indices of auditory-related mTBI pathophysiology beyond pure-tone thresholds for improved hearing healthcare diagnosis and treatment. Given the heterogeneity of mTBI etiology and the diverse peripheral and central processes required for normal auditory function, the present study sought to determine the audiologic assessments sensitive to mTBI pathophysiology at the group level using a well-rounded test battery of both peripheral and central auditory system function. This test battery included pure-tone detection thresholds, word understanding in quiet, sentence understanding in noise, distortion product otoacoustic emissions (DPOAEs), middle-ear muscle reflexes (MEMRs), and auditory evoked potentials (AEPs), including auditory brainstem responses (ABRs), middle latency responses (MLRs), and late latency responses (LLRs). Each participant also received magnetic resonance imaging (MRI). Compared to the control group, we found that individuals with mTBI had reduced DPOAE amplitudes that revealed a compound effect of age, elevated MEMR thresholds for an ipsilateral broadband noise elicitor, longer ABR Wave I latencies for click and 4 kHz tone burst elicitors, longer ABR Wave III latencies for 4 kHz tone bursts, larger MLR Na and Nb amplitudes, smaller MLR Pb amplitudes, longer MLR Pa latencies, and smaller LLR N1 amplitudes for older individuals with mTBI. Further, mTBI individuals with combined hearing difficulty and noise sensitivity had a greater number of deficits on thalamic and cortical AEP measures compared to those with only one/no self-reported auditory symptoms. This finding was corroborated with MRI, which revealed significant structural differences in the auditory cortical areas of mTBI participants who reported combined hearing difficulty and noise sensitivity, including an enlargement of left transverse temporal gyrus (TTG) and bilateral planum polare (PP). These findings highlight the need for continued investigations toward identifying individualized audiologic assessments and treatments that are sensitive to mTBI pathophysiology.

Prenatal depressive symptoms and childhood development of brain limbic and default mode network structure

Prenatal depressive symptoms are linked to negative child behavioral and cognitive outcomes and predict later psychopathology in adolescent children. Prior work links prenatal depressive symptoms to child brain structure in regions like the amygdala; however, the relationship between symptoms and the development of brain structure over time remains unclear. We measured maternal depressive symptoms during pregnancy and acquired longitudinal T1-weighted and diffusion imaging data in children (n = 111; 60 females) between 2.6 and 8 years of age. Controlling for postnatal symptoms, we used linear mixed effects models to test relationships between prenatal depressive symptoms and age-related changes in (i) amygdala and hippocampal volume and (ii) structural properties of the limbic and default-mode networks using graph theory. Higher prenatal depressive symptoms in the second trimester were associated with more curvilinear trajectories of left amygdala volume changes. Higher prenatal depressive symptoms in the third trimester were associated with slower age-related changes in limbic global efficiency and average node degree across childhood. Our work provides evidence that moderate symptoms of prenatal depression in a low sociodemographic risk sample are associated with structural brain development in regions and networks implicated in emotion processing.

Learn2Reg: Comprehensive Multi-Task Medical Image Registration Challenge, Dataset and Evaluation in the Era of Deep Learning

Image registration is a fundamental medical image analysis task, and a wide variety of approaches have been proposed. However, only a few studies have comprehensively compared medical image registration approaches on a wide range of clinically relevant tasks. This limits the development of registration methods, the adoption of research advances into practice, and a fair benchmark across competing approaches. The Learn2Reg challenge addresses these limitations by providing a multi-task medical image registration data set for comprehensive characterisation of deformable registration algorithms. A continuous evaluation will be possible at https://learn2reg.grand-challenge.org. Learn2Reg covers a wide range of anatomies (brain, abdomen, and thorax), modalities (ultrasound, CT, MR), availability of annotations, as well as intra- and inter-patient registration evaluation. We established an easily accessible framework for training and validation of 3D registration methods, which enabled the compilation of results of over 65 individual method submissions from more than 20 unique teams. We used a complementary set of metrics, including robustness, accuracy, plausibility, and runtime, enabling unique insight into the current state-of-the-art of medical image registration. This paper describes datasets, tasks, evaluation methods and results of the challenge, as well as results of further analysis of transferability to new datasets, the importance of label supervision, and resulting bias. While no single approach worked best across all tasks, many methodological aspects could be identified that push the performance of medical image registration to new state-of-the-art performance. Furthermore, we demystified the common belief that conventional registration methods have to be much slower than deep-learning-based methods.

CORRELATES OF PHYSICAL ACTIVITY HISTORY IN PARTICIPANTS OF THE BALTIMORE LONGITUDINAL STUDY OF AGING

Physical activity across the life course contributes to physical function and health in later life. Here we characterize a measure of physical activity history, newly implemented in participants of the Baltimore Longitudinal Study of Aging (n = 690). Participants selected one of four levels to describe activity during each decade of life from age ten to the present. Recalled levels of physical activity are positively associated with activity assessed in current and prior decade study visits, suggesting that the recalled estimates are consistent with historic activity. A summary measure based on ranking activity patterns was associated with measures of physical performance, muscle and fat areas quantified from computed tomography images as well as some indicators of homeostatic dysregulation (p <.05). The observed associations suggest that an estimate of physical activity across decades provides complementary information to estimates of current activity and reemphasizes the importance of consistently engaging in physical activity.

Federated learning enables big data for rare cancer boundary detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.

The effects of prenatal bisphenol A exposure on brain volume of children and young mice

Bisphenol A (BPA) is a synthetic chemical used for the manufacturing of plastics, epoxy resin, and many personal care products. This ubiquitous endocrine disruptor is detectable in the urine of over 80% of North Americans. Although adverse neurodevelopmental outcomes have been observed in children with high gestational exposure to BPA, the effects of prenatal BPA on brain structure remain unclear. Here, using magnetic resonance imaging (MRI), we studied the associations of maternal BPA exposure with children's brain structure, as well as the impact of comparable BPA levels in a mouse model. Our human data showed that most maternal BPA exposure effects on brain volumes were small, with the largest effects observed in the opercular region of the inferior frontal gyrus (ρ = -0.2754), superior occipital gyrus (ρ = -0.2556), and postcentral gyrus (ρ = 0.2384). In mice, gestational exposure to an equivalent level of BPA (2.25 μg BPA/kg bw/day) induced structural alterations in brain regions including the superior olivary complex (SOC) and bed nucleus of stria terminalis (BNST) with larger effect sizes (1.07≤ Cohens d ≤ 1.53). Human (n = 87) and rodent (n = 8 each group) sample sizes, while small, are considered adequate to perform the primary endpoint analysis. Combined, these human and mouse data suggest that gestational exposure to low levels of BPA may have some impacts on the developing brain at the resolution of MRI.

The impact of the lung EDRN-CVC on Phase 1, 2, & 3 biomarker validation studies

The Early Detection Research Network’s (EDRN) purpose is to discover, develop and validate biomarkers and imaging methods to detect early-stage cancers or at-risk individuals. The EDRN is composed of sites that fall into four categories: Biomarker Developmental Laboratories (BDL), Biomarker Reference Laboratories (BRL), Clinical Validation Centers (CVC) and Data Management and Coordinating Centers. Each component has a crucial role to play within the mission of the EDRN. The primary role of the CVCs is to support biomarker developers through validation trials on promising biomarkers discovered by both EDRN and non-EDRN investigators. The second round of funding for the EDRN Lung CVC at Vanderbilt University Medical Center (VUMC) was funded in October 2016 and we intended to accomplish the three missions of the CVCs: To conduct innovative research on the validation of candidate biomarkers for early cancer detection and risk assessment of lung cancer in an observational study; to compare biomarker performance; and to serve as a resource center for collaborative research within the Network and partner with established EDRN BDLs and BRLs, new laboratories and industry partners. This report outlines the impact of the VUMC EDRN Lung CVC and describes the role in promoting and validating biological and imaging biomarkers.

Enabling AI Innovation via Data and Model Sharing: An Overview of the Nsf Convergence Accelerator Track D

This article provides a brief overview of 18 projects funded in Track D—Data and Model Sharing to Enable AI Innovation—of the 2020 Cohort of the National Science Foundation's (NSF) Convergence Accelerator (CA) program. The NSF CA is focused on transitioning research to practice for societal impact. The projects described here were funded for one year in phase I of the program, beginning September 2020. Their focus is on delivering tools, technologies, and techniques to assist in sharing data as well as data-driven models to enable AI innovation. A broad range of domain areas is covered by the funded efforts, spanning across healthcare and medicine, to climate change and disaster, and civil/built infrastructure. The projects are addressing sharing of open as well as sensitive/private data. In September 2021, six of the eighteen projects described here were selected for phase II of the program, as noted in this article.

Relative Vigorous-Intensity Physical Activity Predicts Brain Microstructural Changes in Older Adults

Physical activity especially at moderate-to-vigorous intensity may preserve brain structure in old age. However, current findings are cross-sectional and rely on absolute intensity. This study aimed to examine whether relative or absolute vigorous-intensity physical activity (VPA) predicts brain microstructural changes. We analyzed 260 initially cognitively normal and well-functioning participants(age=70.5yrs) who had VPA data via ActiHeart and longitudinal brain microstructure by DTI(follow-up=3.7yrs). Associations of VPA with microstructural changes were examined using linear mixed-effects models, adjusted for demographics. Each SD higher relative VPA defined by heart rate reserve (i.e. 21 min/day) was significantly associated with less decline in memory-related microstructural integrity, including mean diffusivity of entorhinal cortex and parahippocampal gyrus and fractional anisotropy of uncinate fasciculus and cingulum-hippocampal part, and not executive/motor-related microstructure. Absolute VPA was not associated with microstructural markers. Among well-functioning older adults, participating in VPA defined by heart rate reserve may predict less brain microstructural decline in memory-related areas.

Data for evaluation of the onshore Cretaceous Zululand Basin in South Africa for geological CO2 storage

The world has set the goal of reducing CO2 emissions from burning fossil fuels by using carbon capture and storage (CCS) as one of the major solutions. A sudden and complete switch from fossil fuels to renewable resources cannot be achieved immediately. Therefore, CCS remains an essential techniques to reduce CO2. In this work, the 180 - 65 Ma old onshore part of the Zululand Basin in KwaZulu-Natal in South Africa was investigated for geological CO2 sequestration. A total of 160 core samples of sandstone, conglomerate, tuff, rhyolite, breccia, and siltstone were taken from NZA, ZA, ZB, and ZC drill cores. The wells were drilled in the 1960s by the South African Petroleum and Gas Corporation Company for hydrocarbon exploration. In order to examine the basin suitability for CO2 storage, porosity and permeability, mineralogy, geochemistry, geomechanical properties, and H2O-CO2-rock interactions were investigated using geological core logging, spectral scanning, petrography, X-ray diffraction (XRD), X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry, uniaxial compressive stress, and scanning electron microscopy. The basin comprises clastic sedimentary rocks, pyroclastic deposits and carbonates from the Makatini, Mzinene and St. Lucia formations. Aptian and Cenomanian sandstones are identified as CO2 reservoirs, and the siltstone above is considered capstone. The sandstone comprises on average 34.45 wt% quartz, 32.91 wt% clays, 29.53 wt% feldspars, 4.44 wt% carbonates, 3.10 wt% Fe-oxides, 2.40 wt% micas, and 2.00 wt% organic materials as per XRD data, also contains trace amounts of sulphides and sulphates. Geochemical XRF data for sandstone are 29.72 - 62.51 wt% SiO2, 6.95 - 13.44 wt% Al2O3, 3.06 - 48.81 wt%, 1.90 - 4.51 wt% MgO, 1.04 - 2.19 wt% K2O, 1.00 - 3.67 Na2O wt%. The content of TiO2, Cr2O3 and P2O5 is below 0.01 wt% each. Siltstone has similar mineralogy and geochemistry as sandstone, but high clay content, fine-grained, impervious, with porosity <5%. The sandstone and siltstone are geomechanically soft and recorded 15 MPa on the Enerpac P141 device. CO2-H2O-rock interaction experiments performed at 100 °C and 100 bar using autoclaves showed that sandstone and siltstone react with scCO2.

Mapping gradient nonlinearity and miscalibration using diffusion-weighted MR images of a uniform isotropic phantom

PURPOSE

To use diffusion measurements to map the spatial dependence of the magnetic field produced by the gradient coils of an MRI scanner with sufficient accuracy to correct errors in quantitative diffusion MRI (DMRI) caused by gradient nonlinearity and gradient amplifier miscalibration.

THEORY AND METHODS

The field produced by the gradient coils is expanded in regular solid harmonics. The expansion coefficients are found by fitting a model to a minimum set of diffusion-weighted images of an isotropic diffusion phantom. The accuracy of the resulting gradient coil field maps is evaluated by using them to compute corrected b-matrices that are then used to process a multi-shell diffusion tensor imaging (DTI) dataset with 32 diffusion directions per shell.

RESULTS

The method substantially reduces both the spatial inhomogeneity of the computed mean diffusivities (MD) and the computed values of the fractional anisotropy (FA), as well as virtually eliminating any artifactual directional bias in the tensor field secondary to gradient nonlinearity. When a small scaling miscalibration was purposely introduced in the x, y, and z, the method accurately detected the amount of miscalibration on each gradient axis.

CONCLUSION

The method presented detects and corrects the effects of gradient nonlinearity and gradient gain miscalibration using a simple isotropic diffusion phantom. The correction would improve the accuracy of DMRI measurements in the brain and other organs for both DTI and higher order diffusion analysis. In particular, it would allow calibration of MRI systems, improving data harmony in multicenter studies.

Integrated Biomarkers for the Management of Indeterminate Pulmonary Nodules

Rationale: Patients with indeterminate pulmonary nodules (IPNs) at risk of cancer undergo high rates of invasive, costly, and morbid procedures. Objectives: To train and externally validate a risk prediction model that combined clinical, blood, and imaging biomarkers to improve the noninvasive management of IPNs. Methods: In this prospectively collected, retrospective blinded evaluation study, probability of cancer was calculated for 456 patient nodules using the Mayo Clinic model, and patients were categorized into low-, intermediate-, and high-risk groups. A combined biomarker model (CBM) including clinical variables, serum high sensitivity CYFRA 21-1 level, and a radiomic signature was trained in cohort 1 (n = 170) and validated in cohorts 2-4 (total n = 286). All patients were pooled to recalibrate the model for clinical implementation. The clinical utility of the CBM compared with current clinical care was evaluated in 2 cohorts. Measurements and Main Results: The CBM provided improved diagnostic accuracy over the Mayo Clinic model with an improvement in area under the curve of 0.124 (95% bootstrap confidence interval, 0.091-0.156; P < 2 × 10-16). Applying 10% and 70% risk thresholds resulted in a bias-corrected clinical reclassification index for cases and control subjects of 0.15 and 0.12, respectively. A clinical utility analysis of patient medical records estimated that a CBM-guided strategy would have reduced invasive procedures from 62.9% to 50.6% in the intermediate-risk benign population and shortened the median time to diagnosis of cancer from 60 to 21 days in intermediate-risk cancers. Conclusions: Integration of clinical, blood, and image biomarkers improves noninvasive diagnosis of patients with IPNs, potentially reducing the rate of unnecessary invasive procedures while shortening the time to diagnosis.

Altered gray matter development in pre-reading children with a family history of reading disorder

Reading disorders are common in children and can impact academic success, mental health, and career prospects. Reading is supported by network of interconnected left hemisphere brain regions, including temporo-parietal, occipito-temporal, and inferior-frontal circuits. Poor readers often show hypoactivation and reduced gray matter volumes in this reading network, with hyperactivation and increased volumes in the posterior right hemisphere. We assessed gray matter development longitudinally in pre-reading children aged 2-5 years using magnetic resonance imaging (MRI) (N = 32, 110 MRI scans; mean age: 4.40 ± 0.77 years), half of whom had a family history of reading disorder. The family history group showed slower proportional growth (relative to total brain volume) in the left supramarginal and inferior frontal gyri, and faster proportional growth in the right angular, right fusiform, and bilateral lingual gyri. This suggests delayed development of left hemisphere reading areas in children with a family history of dyslexia, along with faster growth in right homologues. This alternate development pattern may predispose the brain to later reading difficulties and may later manifest as the commonly noted compensatory mechanisms. The results of this study further shows our understanding of structural brain alterations that may form the neurological basis of reading difficulties.

Multi-Site Infant Brain Segmentation Algorithms: The iSeg-2019 Challenge

To better understand early brain development in health and disorder, it is critical to accurately segment infant brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). Deep learning-based methods have achieved state-of-the-art performance; h owever, one of the major limitations is that the learning-based methods may suffer from the multi-site issue, that is, the models trained on a dataset from one site may not be applicable to the datasets acquired from other sites with different imaging protocols/scanners. To promote methodological development in the community, the iSeg-2019 challenge (http://iseg2019.web.unc.edu) provides a set of 6-month infant subjects from multiple sites with different protocols/scanners for the participating methods. T raining/validation subjects are from UNC (MAP) and testing subjects are from UNC/UMN (BCP), Stanford University, and Emory University. By the time of writing, there are 30 automatic segmentation methods participated in the iSeg-2019. In this article, 8 top-ranked methods were reviewed by detailing their pipelines/implementations, presenting experimental results, and evaluating performance across different sites in terms of whole brain, regions of interest, and gyral landmark curves. We further pointed out their limitations and possible directions for addressing the multi-site issue. We find that multi-site consistency is still an open issue. We hope that the multi-site dataset in the iSeg-2019 and this review article will attract more researchers to address the challenging and critical multi-site issue in practice.

Prenatal and postnatal maternal anxiety and amygdala structure and function in young children

Anxiety symptoms are relatively common during pregnancy and are associated with behavioural problems in children. The amygdala is involved in emotion regulation, and its volume and function are associated with exposure to prenatal maternal depression. The associations between perinatal maternal anxiety and children's amygdala structure and function remain unclear. The objective of this study was to determine associations between prenatal and postnatal maternal anxiety and amygdala structure and function in children. Maternal anxiety was measured during the second trimester of pregnancy and 12 weeks postpartum. T1-weighted anatomical data and functional magnetic resonance imaging data were collected from 54 children (25 females), between the ages of 3-7 years. Amygdala volume was calculated and functional connectivity maps were created between the amygdalae and the rest of the brain. Spearman correlations were used to test associations between amygdala volume/functional connectivity and maternal anxiety symptoms, controlling for maternal depression symptoms. Second trimester maternal anxiety symptoms were negatively associated with functional connectivity between the left amygdala and clusters in bilateral parietal regions; higher maternal anxiety was associated with increased negative connectivity. Postnatal maternal anxiety symptoms were positively associated with child amygdala volume, but this finding did not remain significant while controlling for total brain volume. These functional connectivity differences may underlie behavioral outcomes in children exposed to maternal anxiety during pregnancy.

Microstructural Neuroimaging of Frailty in Cognitively Normal Older Adults

Physical frailty is an age-related clinical syndrome that is related to adverse health outcomes, including cognitive impairment and dementia. Recent studies have shown structural neuroimaging correlates with frailty. However, most existing evidence relies on brain volumetric measures. Whether brain microstructure is associated with frailty and its spatial distribution have not been explored. In the Baltimore Longitudinal Study of Aging, we identified 776 cognitively normal participants aged 50 and older who had concurrent data on frailty and brain microstructure by diffusion tensor imaging (DTI), including mean diffusivity (MD) of gray matter and fractional anisotropy (FA) of white matter. We first identified neuroimaging markers that were associated with frailty score (0-5) and further examined their relationships with frailty status (0: non-frail, 1-2: pre-frail, 3+: frail) using multivariate linear regression. Models were adjusted for age, sex, race, years of education, and Apolipoprotein E e4 carrier status. DTI-based neuroimaging markers that were associated with frailty status were localized in the supplementary motor area of the frontal lobe, several subcortical regions (putamen, caudate), and body and splenium of corpus callosum. This study demonstrates for the first time that microstructure of both gray and white matter differs by frailty levels in cognitively normal older adults. Brain areas were not widespread, but mostly localized in gray matter subcortical motor areas and white matter corpus callosum. Whether changes in brain microstructure precede future frailty development warrants further investigation.

Network localization of clinical, cognitive, and neuropsychiatric symptoms in Alzheimer's disease

There is both clinical and neuroanatomical variability at the single-subject level in Alzheimer's disease, complicating our understanding of brain-behaviour relationships and making it challenging to develop neuroimaging biomarkers to track disease severity, progression, and response to treatment. Prior work has shown that both group-level atrophy in clinical dementia syndromes and complex neurological symptoms in patients with focal brain lesions localize to brain networks. Here, we use a new technique termed 'atrophy network mapping' to test the hypothesis that single-subject atrophy maps in patients with a clinical diagnosis of Alzheimer's disease will also localize to syndrome-specific and symptom-specific brain networks. First, we defined single-subject atrophy maps by comparing cortical thickness in each Alzheimer's disease patient versus a group of age-matched, cognitively normal subjects across two independent datasets (total Alzheimer's disease patients = 330). No more than 42% of Alzheimer's disease patients had atrophy at any given location across these datasets. Next, we determined the network of brain regions functionally connected to each Alzheimer's disease patient's location of atrophy using seed-based functional connectivity in a large (n = 1000) normative connectome. Despite the heterogeneity of atrophied regions at the single-subject level, we found that 100% of patients with a clinical diagnosis of Alzheimer's disease had atrophy functionally connected to the same brain regions in the mesial temporal lobe, precuneus cortex, and angular gyrus. Results were specific versus control subjects and replicated across two independent datasets. Finally, we used atrophy network mapping to define symptom-specific networks for impaired memory and delusions, finding that our results matched symptom networks derived from patients with focal brain lesions. Our study supports atrophy network mapping as a method to localize clinical, cognitive, and neuropsychiatric symptoms to brain networks, providing insight into brain-behaviour relationships in patients with dementia.

Abstract 3317: Development of a lung nodule cohort with integrated clinical, molecular and imaging biomarkers

Background: We are facing an epidemic of indeterminate pulmonary nodules (IPN). Current diagnostic strategies lack accuracy such that the management of IPNs 6-30 mm leads to an unacceptable rate of invasive biopsies and of missed opportunities for cure. Based on the critical need of evaluating candidate biomarkers across heterogeneous populations, we intended to assemble a large cohort of fully annotated IPNs from five collaborative institutions.

Methods: Standard operating procedures (SOPs) were developed to capture subject demographics and assign consistent identifiers across clinical, bio-specimens, and imaging data. REDCap database was created for clinical, imaging and biospecimen data capture. Sample collection, processing, storage and shipping SOPs were created and shared among institutions to assure for consistency and quality accuracy. DICOM files, demographic and clinical data, blood and tissue samples were collected prospectively through IRB approved studies at each institution (VUMC, Nashville VAMC, Moffitt Cancer Center, and UPMC). Imaging studies and specimens were de-identified locally using custom JavaScript program in a secure web browser and assigned as specific identifier. De-identified thin slice, non-contrast chest CT studies were tested for quality control and transmitted to an imaging repository (eXtensible Neuroimaging Repository-XNAT) that can be mined by all collaborators.

Results: To date, a cohort of 845 subjects, 507 (60%) males and 338 (40%) females, with lung nodules was assembled. 36 % are current smokers, 56 % former smokers and 8% never smokers, with an average of 46 pack year smoking history. Clinical data including risk prediction models such as the Mayo and PLCO m2012 are reported. Pathological confirmation of nodules is available for 322 benign and 444 malignant nodules. The cohort 283 lung adenocarcinomas, 71 squamous cell carcinomas, 53 small cell carcinoma, 17 non-small cell lung cancer, 9 carcinoid, and 79 subjects considered benign based on CT follow without growth. Serum, plasma and peripheral blood monocyte related DNA is available on all. All diagnostic chest CT are available in our thoracic imaging repository (XNAT) in a de-identified format.

Conclusions: We assembled a unique cohort of incidental and screening detected lung nodules prospectively enrolled at four institutions for which full clinical data capture, chest CT DICOM files and blood specimens were collected. This repository allows the derivation and independent validation of candidate molecular and imaging biomarkers for the management of IPNs. This work is supported by UO1 152662, UO1CA186145 and UO1CA196405

Citation Format: Sanja Antic, Travis Osterman, Aneri Balar, Dhairya Lakhani, Rina Nguyen, Sara Block, Kimberly Fileds, Brandon Winston, Anel Muterspaugh, Yuankai Huo, Riqiang Gao, Joseph Leader, David Wilson, Viswam Nair, Robert Gillies, Matthew Schabath, Chirayu Shah, Bennett Landman, Pierre Massion. Development of a lung nodule cohort with integrated clinical, molecular and imaging biomarkers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3317.

Imaging biomarkers in thyroid eye disease and their clinical associations

The purpose of this study is to understand the phenotypes of thyroid eye disease (TED) through data derived from a multiatlas segmentation of computed tomography (CT) imaging. Images of 170 orbits of 85 retrospectively selected TED patients were analyzed with the developed automated segmentation tool. Twenty-five bilateral orbital structural metrics were used to perform principal component analysis (PCA). PCA of the 25 structural metrics identified the two most dominant structural phenotypes or characteristics, the "big volume phenotype" and the "stretched optic nerve phenotype," that accounted for 60% of the variance. Most of the subjects in the study have either of these characteristics or a combination of both. A Kendall rank correlation between the principal components (phenotypes) and clinical data showed that the big volume phenotype was very strongly correlated ( p - value < 0.05 ) with motility defects, and loss of visual acuity. Whereas, the stretched optic nerve phenotype was strongly correlated ( p - value < 0.05 ) with an increased Hertel measurement, relatively better visual acuity, and smoking. Two clinical subtypes of TED, type 1 with enlarged muscles and type 2 with proptosis, are recognizable in CT imaging. Our automated algorithm identifies the phenotypes and finds associations with clinical markers.

Abstract 3723: Assessing the reproducibility of computer-aided nodule assessment and risk yield (CANARY) method to characterize lung adenocarcinomas

This study assessed the inter-user reproducibility of Computer-Aided Nodule Assessment and Risk Yield (CANARY), a novel analytical tool that risk stratifies lung adenocarcinomas (ADCs) according to defined computed tomography (CT) structural characteristics. CANARY detects nine distinct voxel signatures in ADCs based on standard CT imaging, thereby defining nodule characteristics correlating with patient outcomes, and corresponding to invasion or lepidic growth histologically. A software user segments the borders of each ADC prior to voxel analysis, introducing potential variability into the assessment. While CANARY is a promising method, it requires validation of the analytical variability between users and prediction of accuracy in an independent cohort. To evaluate the reproducibility of CANARY analysis, three independent users who are not part of the CANARY development team segmented and analyzed 50 biopsy-confirmed primary lung ADCs from Vanderbilt University Medical Center. The CT scans of ADCs were selected retrospectively based on the following criteria: ADC-histology proven on biopsy, diagnosed between 2009-2015, less than 3cm in greatest diameter, and stages IA-IV. Users followed a standard operating procedure established at the Mayo Clinic, and were blinded to clinical characteristics and patient outcomes.

Results: To measure inter-user variability of ADC voxel composition, the intraclass correlation coefficient (ICC) was calculated based upon the percentage of each voxel subtype within the whole ADC. An ICC of 1 reflects high reproducibility between users. Amongst all 50 ADCs, the average ICC for all nine voxel types was 0.828 (95% CI 0.76, 0.895). The ICC of the four voxel types associated with invasive features on CT was 0.865 (95% CI 0.805, 0.924). ICCs were also calculated using a logarithmic transformation for data normalization, generating an ICC of 0.745 (95% CI 0.663, 0.826) for all nine voxel types, and an ICC of 0.995 (95% CI 0.993, 0.997) for the four voxel types associated with invasion. Conclusions: (1) CANARY analysis of lung ADC voxel signatures appears to be reproducible amongst users, making it a reliable tool for the evaluation of ADC voxel density. (2) Correlation of invasive signatures associated with more aggressive ADCs was nearly perfect amongst users. Additional validation metrics for CANARY with larger datasets are being evaluated, including the accuracy of tumor prognostic predictions between users and analysis of ADC datasets from other institutions.

Citation Format: Erica C. Nakajima, Michael P. Frankland, Tucker Johnson, Sanja L. Antic, Ronald A. Karwoski, Bennett Landman, Heidi Chen, Ronald C. Walker, Brian J. Bartholmai, Tobias Peikert, Srinivasan Rajagopalan, Pierre P. Massion, Fabien Maldonado. Assessing the reproducibility of computer-aided nodule assessment and risk yield (CANARY) method to characterize lung adenocarcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3723. doi:10.1158/1538-7445.AM2017-3723

Cortical asymmetry in Parkinson's disease: early susceptibility of the left hemisphere

BACKGROUND AND PURPOSE

Clinically, Parkinson's disease (PD) presents with asymmetric motor symptoms. The left nigrostriatal system appears more susceptible to early degeneration than the right, and a left-lateralized pattern of early neuropathological changes is also described in several neurodegenerative conditions, including Alzheimer's disease, frontotemporal dementia, and Huntington's disease. In this study, we evaluated hemispheric differences in estimated rates of atrophy in a large, well-characterized cohort of PD patients.

METHODS

Our cohort included 205 PD patients who underwent clinical assessments and T1-weighted brain MRI's. Patients were classified into Early (n = 109) and Late stage (n = 96) based on disease duration, defined as greater than or less than 10 years of motor symptoms. Cortical thickness was determined using FreeSurfer, and a bootstrapped linear regression model was used to estimate differences in rates of atrophy between Early and Late patients.

RESULTS

Our results show that patients classified as Early stage exhibit a greater estimated rate of cortical atrophy in left frontal regions, especially the left insula and olfactory sulcus. This pattern was replicated in left-handed patients, and was not influenced by the degree of motor symptom asymmetry (i.e., left-sided predominant motor symptoms). Patients classified as Late stage exhibited greater atrophy in the bilateral occipital, and right hemisphere-predominant cortical areas.

CONCLUSIONS

We show that cortical degeneration in PD differs between cerebral hemispheres, and findings suggest a pattern of early left, and late right hemisphere with posterior cortical atrophy. Further investigation is warranted to elucidate the underlying mechanisms of this asymmetry and pathologic implications.

The Attenuation Distribution Across the Long Axis (ADLA): Preliminary Findings for Assessing Response to Cancer Treatment

RATIONALE AND OBJECTIVES

Novel image analysis methods may be useful adjuncts to standard cancer treatment response assessment techniques. The attenuation distribution across the long axis (ADLA) is a simple measure of lesion heterogeneity that can be obtained while measuring the long axis diameter of a target lesion. The purpose of this study was to obtain preliminary validation of the ADLA method for predicting treatment response in a small clinical trial.

MATERIALS AND METHODS

Under an Institutional Review Board waiver, we obtained de-identified imaging and clinical data from a phase 2 trial of an investigational anticancer therapy at our institution. We retrospectively analyzed all patients with at least one liver metastasis measuring ≥15 mm on baseline contrast-enhanced computed tomography. For each patient at every imaging time point, up to two target liver lesions were evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and ADLA measurements. The ADLA was obtained as the standard deviation of the post-contrast computed tomography attenuation values in the portal venous phase across a linear function spanning the long-axis diameter. Using Kaplan-Meier survival analysis, the log-rank test was used to evaluate the ability of RECIST 1.1 and ADLA measurements to discriminate patients with longer overall survival (OS).

RESULTS

Fifteen patients met inclusion criteria. Median survival was 149 days (range 57-487). Best overall response by the ADLA method successfully separated patients with longer OS (p = .04). Best overall response by RECIST 1.1 did not discriminate patients with longer survival (P > .05).

CONCLUSION

In retrospective data analysis from a phase 2 clinical trial, the ADLA method was more predictive of OS than RECIST 1.1. Further studies are needed to explore the utility of this measurement in predicting response to cancer treatment.

Structural Functional Associations of the Orbit in Thyroid Eye Disease: Kalman Filters to Track Extraocular Rectal Muscles

Pathologies of the optic nerve and orbit impact millions of Americans and quantitative assessment of the orbital structures on 3-D imaging would provide objective markers to enhance diagnostic accuracy, improve timely intervention and eventually preserve visual function. Recent studies have shown that the multi-atlas methodology is suitable for identifying orbital structures, but challenges arise in the identification of the individual extraocular rectus muscles that control eye movement. This is increasingly problematic in diseased eyes, where these muscles often appear to fuse at the back of the orbit (at the resolution of clinical computed tomography imaging) due to inflammation or crowding. We propose the use of Kalman filters to track the muscles in three-dimensions to refine multi-atlas segmentation and resolve ambiguity due to imaging resolution, noise, and artifacts. The purpose of our study is to investigate a method of automatically generating orbital metrics from CT imaging and demonstrate the utility of the approach by correlating structural metrics of the eye orbit with clinical data and visual function measures in subjects with thyroid eye disease. The pilot study demonstrates that automatically calculated orbital metrics are strongly correlated with several clinical characteristics. Moreover, the superior, inferior, medial and lateral rectus muscles obtained using Kalman filters are each correlated with different categories of functional deficit. These findings serve as foundation for further investigation in the use of CT imaging in the study, analysis and diagnosis of ocular diseases, specifically thyroid eye disease.

Region of interest correction factors improve reliability of diffusion imaging measures within and across scanners and field strengths

Diffusion tensor imaging (DTI) measures are commonly used as imaging markers to investigate individual differences in relation to behavioral and health-related characteristics. However, the ability to detect reliable associations in cross-sectional or longitudinal studies is limited by the reliability of the diffusion measures. Several studies have examined the reliability of diffusion measures within (i.e. intra-site) and across (i.e. inter-site) scanners with mixed results. Our study compares the test-retest reliability of diffusion measures within and across scanners and field strengths in cognitively normal older adults with a follow-up interval less than 2.25 years. Intra-class correlation (ICC) and coefficient of variation (CoV) of fractional anisotropy (FA) and mean diffusivity (MD) were evaluated in sixteen white matter and twenty-six gray matter bilateral regions. The ICC for intra-site reliability (0.32 to 0.96 for FA and 0.18 to 0.95 for MD in white matter regions; 0.27 to 0.89 for MD and 0.03 to 0.79 for FA in gray matter regions) and inter-site reliability (0.28 to 0.95 for FA in white matter regions, 0.02 to 0.86 for MD in gray matter regions) with longer follow-up intervals were similar to earlier studies using shorter follow-up intervals. The reliability of across field strengths comparisons was lower than intra- and inter-site reliabilities. Within and across scanner comparisons showed that diffusion measures were more stable in larger white matter regions (>1500 mm(3)). For gray matter regions, the MD measure showed stability in specific regions and was not dependent on region size. Linear correction factor estimated from cross-sectional or longitudinal data improved the reliability across field strengths. Our findings indicate that investigations relating diffusion measures to external variables must consider variable reliability across the distinct regions of interest and that correction factors can be used to improve consistency of measurement across field strengths. An important result of this work is that inter-scanner and field strength effects can be partially mitigated with linear correction factors specific to regions of interest. These data-driven linear correction techniques can be applied in cross-sectional or longitudinal studies.

Voxelwise Relationships Between Distribution Volume Ratio and Cerebral Blood Flow: Implications for Analysis of β-Amyloid Images

Quantification of β-amyloid (Aβ) in vivo is often accomplished using the distribution volume ratio (DVR), based on a simplified reference tissue model. We investigated the local relationships between DVR and cerebral blood flow (CBF), as well as relative CBF (R1), in nondemented older adults.

METHODS

Fifty-five nondemented participants (mean age, 78.5 y) in the Baltimore Longitudinal Study of Aging underwent (15)O-H2O PET CBF and dynamic (11)C-PiB PET. (15)O-H2O PET images were normalized and smoothed using SPM. A simplified reference tissue model with linear regression and spatial constraints was used to generate parametric DVR images. The DVR images were regressed on CBF images on a voxel-by-voxel basis using robust biologic parametric mapping, adjusting for age and sex (false discovery rate, P = 0.05; spatial extent, 50 voxels). DVR images were also regressed on R1 images, a measure of the transport rate constant from vascular space to tissue. All analyses were performed on the entire sample, and on high and low tertiles of mean cortical DVR.

RESULTS

Voxel-based analyses showed that increased DVR is associated with increased CBF in the frontal, parietal, temporal, and occipital cortices. However, this association appears to spare regions that typically show early Aβ deposition. A more robust relationship between DVR and CBF was observed in the lower tertile of DVR, that is, negligible cortical Aβ load, compared with the upper tertile of cortical DVR and Aβ load. The spatial distributions of the DVR-CBF and DVR-R1 correlations showed similar patterns. No reliable negative voxelwise relationships between DVR and CBF or R1 were observed.

CONCLUSION

Robust associations between DVR and CBF at negligible Aβ levels, together with similar spatial distributions of DVR-CBF and DVR-R1 correlations, suggest that regional distribution of DVR reflects blood flow and tracer influx rather than pattern of Aβ deposition in those with minimal Aβ load. DVR-CBF associations in individuals with a higher DVR are more likely to reflect true associations between patterns of Aβ deposition and CBF or neural activity. These findings have important implications for analysis and interpretation of voxelwise correlations with external variables in individuals with varying amounts of Aβ load.

Heritability of fractional anisotropy in human white matter: a comparison of Human Connectome Project and ENIGMA-DTI data

The degree to which genetic factors influence brain connectivity is beginning to be understood. Large-scale efforts are underway to map the profile of genetic effects in various brain regions. The NIH-funded Human Connectome Project (HCP) is providing data valuable for analyzing the degree of genetic influence underlying brain connectivity revealed by state-of-the-art neuroimaging methods. We calculated the heritability of the fractional anisotropy (FA) measure derived from diffusion tensor imaging (DTI) reconstruction in 481 HCP subjects (194/287 M/F) consisting of 57/60 pairs of mono- and dizygotic twins, and 246 siblings. FA measurements were derived using (Enhancing NeuroImaging Genetics through Meta-Analysis) ENIGMA DTI protocols and heritability estimates were calculated using the SOLAR-Eclipse imaging genetic analysis package. We compared heritability estimates derived from HCP data to those publicly available through the ENIGMA-DTI consortium, which were pooled together from five-family based studies across the US, Europe, and Australia. FA measurements from the HCP cohort for eleven major white matter tracts were highly heritable (h(2)=0.53-0.90, p<10(-5)), and were significantly correlated with the joint-analytical estimates from the ENIGMA cohort on the tract and voxel-wise levels. The similarity in regional heritability suggests that the additive genetic contribution to white matter microstructure is consistent across populations and imaging acquisition parameters. It also suggests that the overarching genetic influence provides an opportunity to define a common genetic search space for future gene-discovery studies. Uniquely, the measurements of additive genetic contribution performed in this study can be repeated using online genetic analysis tools provided by the HCP ConnectomeDB web application.

A framework on surface-based connectivity quantification for the human brain

Quantifying the connectivity between arbitrary surface patches in the human brain cortex can be used in studies on brain function and to characterize clinical diseases involving abnormal connectivity. Cortical regions of human brain in their natural forms can be represented in surface formats. In this paper, we present a framework to quantify connectivity using cortical surface segmentation and labeling from structural magnetic resonance images, tractography from diffusion tensor images, and nonlinear inter-subject registration. For a single subject, the connectivity intensity of any point on the cortical surface is set to unity if the point is connected and zero if it is not connected. The connectivity proportion is defined as the ratio of the total connected surface area to the total area of the surface patch. By nonlinearly registering the connectivity data of a group of normal controls into a template space, a population connectivity metric can be defined as either the average connectivity intensity of a cortical point or the average connectivity proportion of a cortical region. In the template space, a connectivity profile and a connectivity histogram of an arbitrary cortical region of interest can then be derived from these connectivity quantification values. Results from the application of these quantification metrics to a population of schizophrenia patients and normal controls are presented, revealing connectivity signatures of specified cortical regions and detecting connectivity abnormalities.

Effect of oral appliances on genioglossus muscle tonicity seen with diffusion tensor imaging: a pilot study

OBJECTIVE

The purpose of this study was to examine whether the diffusion tensor imaging (DTI) technique can be used as a modality to represent the structural deformation in the in vivo genioglossus (GG) muscle fibers with oral appliances (OAs).

STUDY DESIGN

Three healthy subjects were recruited for the pilot study. A custom-made OA, which is modified from a tongue retaining device (TRD), was constructed for each subject before the DTI acquisitions. Recordings were made with and without OAs to compare the GG muscle fiber deformation.

RESULT

DTI provided good resolution of tongue muscle fibers in vivo and successful isolation of each muscle fiber bundle. In particular, the GG muscle fiber deformation due to OAs was clearly visualized.

CONCLUSIONS

This DTI technique may be used not only to identify the individual myoarchitecture, but also to assess muscle fiber deformations in vivo, such as constriction, dilatation, and rotation with OAs. Clinical studies for OSA patients will be the next step.

212 INSEMINATION OF OVUM PICKUP-DERIVED DAIRY COWS RESULTS IN OFFSPRING WITH NORMAL BIRTH WEIGHT

Animals derived by ovum pickup-in vitro production (OPU-IVP) have a higher birth weight compared with animals derived by AI (Wagtendonk et al. 2000 Theriogenology 53, 575–597). It has been suggested that this higher birth weight is the result of epigenetic changes such as aberrant methylation and gene expression pattern, which are caused by the presence of serum in the culture medium (Wrenzycki et al. 2004 Anim. Reprod. Sci. 82–83, 593–603). The present study aimed to investigate whether the higher birth weight, possibly caused by epigenetic changes, is a permanent characteristic that is transmitted to the offspring. We therefore monitored the birth weight of calves born after insemination of OPU-IVP-derived animals. Ovum pickup-IVP was performed according to routine procedures. Immature COC were recovered by OPU. The COC were matured in vitro in TCM-199 supplemented with fetal calf serum (FCS)/LH/FSH. Subsequently, matured oocytes were fertilized with frozen–thawed gradient-separated semen and further cultured for 7 days in TCM-199/10% FCS on a BRL monolayer (CoCul group) or in SOFaaBSA (SOF group). First-generation OPU-IVP animals were produced from oocytes collected by OPU of AI-derived animals. The second generation was produced by inseminating OPU-IVP animals. Calves generated by inseminating AI animals were used as a control group. Birth weights of control AI, first-generation, and second-generation calves were analyzed by using restricted maximum likelihood (Genstat 9.1). Model Birth Weight: *Fixed: Parity Recipient + Sex + Gestation Length + Year + Embryo Type (AI, first, or second generation) + Culture System (CoCul or SOF). *Random: Sire + Barn. The results (Table 1) clearly show that the first-generation (OPU-IVP) calves had, on average, a 3.4-kg greater birth weight than the AI calves. The second-generation calves, however, had approximately the same birth weight as the calves in the AI control group. Our results indicated that the high birth weight of OPU-IVP-derived calves is not a permanent characteristic that is transmitted to their offspring. Previous studies have demonstrated that the fertility of OPU-IVP-derived animals is in the normal range (Wagtendonk et al. 2000 Theriogenology 53, 575–597). Table 1. Birth weight (least squares means ± SE) of AI calves (control), first generation OPU-IVP-derived calves, and second generation AI derived calves from OPU-IVP mothers

Diffusion Tensor Estimation by Maximizing Rician Likelihood

Diffusion tensor imaging (DTI) is widely used to characterize white matter in health and disease. Previous approaches to the estimation of diffusion tensors have either been statistically suboptimal or have used Gaussian approximations of the underlying noise structure, which is Rician in reality. This can cause quantities derived from these tensors - e.g., fractional anisotropy and apparent diffusion coefficient - to diverge from their true values, potentially leading to artifactual changes that confound clinically significant ones. This paper presents a novel maximum likelihood approach to tensor estimation, denoted Diffusion Tensor Estimation by Maximizing Rician Likelihood (DTEMRL). In contrast to previous approaches, DTEMRL considers the joint distribution of all observed data in the context of an augmented tensor model to account for variable levels of Rician noise. To improve numeric stability and prevent non-physical solutions, DTEMRL incorporates a robust characterization of positive definite tensors and a new estimator of underlying noise variance. In simulated and clinical data, mean squared error metrics show consistent and significant improvements from low clinical SNR to high SNR. DTEMRL may be readily supplemented with spatial regularization or a priori tensor distributions for Bayesian tensor estimation.

Ways to improve the biosecurity of bovine semen

Semen production and trade is a worldwide industry. A framework, based on international standards is awaiting international and national regulation. In the perspective of biosecurity of the final product, critical notes can be made according to the semen production regulation and product safety. Process description brings the obligatory health standards for the production bulls, collection and processing of semen, identification, registration, worldwide distribution and insemination into discussion. Test frequency, test quality and demands, way of sampling and test consistency can influence product safety. New scientific knowledge can influence the value of the regulation. Whether a country is free of notifiable disease should influence decisions regarding necessary tests for the production bulls. The biosecurity of the semen production process is influenced by several factors. The effectiveness of the antibiotics used is questionable. The extenders for cryopreservation added to the semen can affect product safety. The way materials and storage containers have to be disinfected must be clear. In modern industry, tracking and tracing is an important issue. Worldwide differences in ways of identification of straws do not benefit a proper identification and registration throughout the process. Regulation could help improve the transparency of production and trade. Before anything concerning biohazard is implemented in regulation, each rule should be thoroughly based on scientific research where possible and furthermore it must be possible to enforce the regulation. The effort it takes to enforce the regulation should be in balance with the benefit it provides. An approach to alter regulation quickly is advisable. To produce a safe product that is accepted for international trade is of vital interest for the survival of artificial insemination (AI) in cattle.

Brain atrophy in long-term abstinent alcoholics who demonstrate impairment on a simulated gambling task

We recently demonstrated impairment on the Simulated Gambling Task (SGT) in long-term abstinent alcoholics (AbsAlc). Brain regions that have been shown to be necessary for intact SGT performance are the ventromedial prefrontal cortex (VMPFC) and the amygdala; patients with VMPFC or amygdalar damage demonstrate SGT impairments similar to those of substance abusing populations. We examined these brain regions, using T1-weighted MRIs, in the 101 participants from our previous study using voxel-based morphometry (VBM). VBM was performed using a modification we developed [Fein, G., Landman, B., Tran, H., Barakos, J., Moon, K., Di Sclafani, V., Shumway, R., 2006. Statistical parametric mapping of brain morphology: sensitivity is dramatically increased by using brain-extracted images as inputs. Neuroimage] of Baron's procedure, [], in which we use skull-stripped images as input. We also restricted the analysis to a ROI consisting of the amygdala and VMPFC as defined by the Talairach Daemon resource. Compared to the controls, the AbsAlc participants had significant foci of reduced gray matter density within the amygdala. Thus, SGT decision-making deficits are associated with reduced gray matter in the amygdala, a brain region previously implicated in similar decision-making impairments in neurological samples. This structurally based abnormality may be the result of long-term alcohol abuse or dependence, or it may reflect a pre-existing factor that predisposes one to severe alcoholism. From an image analysis perspective, this work demonstrates the increased sensitivity that results from using skull-stripped inputs and from restricting the analysis to a ROI. Without both of these methodological advances, no statistically significant finding would have been forthcoming from this work.

Statistical parametric mapping of brain morphology: sensitivity is dramatically increased by using brain-extracted images as inputs

A major attraction of voxel-based morphometry (VBM) is that it allows researchers to explore large datasets with minimal human intervention. However, the validity and sensitivity of the Statistical Parametric Mapping (SPM2) approach to VBM are the subject of considerable debate. We visually inspected the SPM2 gray matter segmentations for 101 research participants and found a gross inclusion of non-brain tissue surrounding the entire brain as gray matter in five subjects and focal areas bordering the brain in which non-brain tissue was classified as gray matter in many other subjects. We also found many areas in which the cortical gray matter was incorrectly excluded from the segmentation of the brain. The major source of these errors was the misregistration of individual brain images with the reference T1-weighted brain template. These errors could be eliminated if SPM2 operated on images from which non-brain tissues (scalp, skull, and meninges) are removed (brain-extracted images). We developed a modified SPM2 processing pipeline that used brain-extracted images as inputs to test this hypothesis. We describe the modifications to the SPM2 pipeline that allow analysis of brain-extracted inputs. Using brain-extracted inputs eliminated the non-brain matter inclusions and the cortical gray matter exclusions noted above, reducing the residual mean square errors (RMSEs, the error term of the SPM2 statistical analyses) by over 30%. We show how this reduction in the RMSEs profoundly affects power analyses. SPM2 analyses of brain-extracted images may require sample sizes only half as great as analyses of non-brain-extracted images.

287 EFFECT OF CYSTEAMINE DURING IN VITRO MATURATION OF OPU DERIVED BOVINE OOCYTES ON FURTHER IN VITRO EMBRYONIC DEVELOPMENT AND PREGNANCY RATE

Glutathione (GSH) plays an important protective role in relation to reactive oxygen species generated by normal oxidative metabolism in the cell. The presence of cysteamine during in vitro maturation may facilitate the synthesis of GSH by immature oocytes. In a previous study we showed a positive effect of the presence of cysteamine during in vitro maturation of slaughterhouse derived bovine oocytes on subsequent in vitro embryonic development (Merton et al. 2004 Rep. Fert. Dev. 16, 279 abstract). This report shows the results of a field trial with ultrasound guided transvaginal oocyte collection (OPU) derived oocytes, in order to confirm our previous results obtained with slaughterhouse derived oocytes. Immature cumulus–oocyte complexes (COCs) were recovered twice weekly by ovum pick-up (OPU) at two collection centres from 11 cows and 147 pregnant heifers. COCs were matured in vitro in TCM199/FCS/LH/FSH supplemented either with or without cysteamine (0.1 mM). Subsequently, matured oocytes were fertilised with frozen-thawed gradient-separated semen and further cultured for 7 days in SOFaaBSA. At Day 7, Morula grade 1 (IETS) were transferred fresh and early-, mid- and exp-Blast grade 1 and 2 were transferred either fresh or frozen/thawed. The experimental design was a 2 × 2 factorial. Results were analysed by Chi-square analyses. The results show that the presence of cysteamine during in vitro maturation significantly affected embryo production from OPU derived COCs (23.4% and 34.4% Morula + Blastocyst rate at Day 7 for control and cysteamine, respectively; Table 1). This higher embryo production rate was mainly due to an increased number of Blastocysts. Also the proportion of grade 3 embryos was significantly reduced in the cysteamine group (P < 0.01). The number of transferable embryos per session was 1.06 and 1.73 for control and cysteamine, respectively. Pregnancy rate was not significantly affected by the presence of cysteamine during in vitro maturation for both fresh and frozen/thawed embryos (fresh: 40.5% and 44.8%, frozen/thawed: 44.4% and 47.2% for control and cysteamine, respectively). These results show that the presence of cysteamine during in vitro maturation affects further in vitro embryonic development, resulting in a higher embryo production rate. This suggest that an apparently ‘simple’ extra protection of the oocyte, due to the free radical scavenging potency of GSH, can have an enormous effect (63.2% relative increase in transferable embryos) on its in vitro developmental potency. The intrinsic quality of the ‘extra’ produced transferable embryos seems not to be different, since pregnancy rate was not affected. Table 1. Effect of cysteamine during in vitro maturation of OPU-derived bovine oocytes on subsequent in vitro embryonic development

Treated and treatment-naive alcoholics come from different populations

In most research on alcoholism, convenience samples of individuals who have been in some type of treatment are used. Berkson's fallacy results when the associations found in studies of select samples are incorrectly presumed to apply to all alcoholics (i.e., including untreated alcoholics in the general population). In the current study, we examined whether treated and untreated alcoholics have similar early alcohol use histories by comparing abstinent alcoholics (treated and sober at least 6 months) with treatment-naive alcoholics (active drinkers). We studied 14 pairs of women and 25 pairs of men matched on the age at which they first met criteria for heavy alcohol use (women, 80 drinks per month; men, 100 drinks per month). The timeline follow-back interview method was used to gather retrospective alcohol use information. Alcohol dose and duration of use were subsequently computed for two intervals: (1) time between the person's first drink and date at which the person met criteria for heavy drinking and (2) period between when criteria for heavy drinking were met and current age of the treatment-naive person from each pair. During the period before the matching "heavy drinking" criteria were met, alcohol dose did not differ between groups. In the period after criteria for heavy alcohol use were met, in comparison with treatment-naive alcoholics, the treated alcoholics had higher average and peak alcohol doses. We rejected the hypothesis that the treatment-naive alcoholics and the treated alcoholics have similar alcohol use trajectories over time, with the treatment-naive sample simply being observed earlier in its alcohol use histories. Instead, we concluded that the two groups come from different populations with regard to alcohol use. In fact, the treated alcoholics had alcohol doses more than 50% higher than those of treatment-naive alcoholics in the years just after they began drinking heavily. This finding supports the suggestion that results from studies of alcoholics in treatment or after treatment (i.e., most studies of alcoholics) cannot be generalized to untreated individuals (who make up the majority of alcoholics).

Treated and treatment-naive alcoholics come from different populations

In most research on alcoholism, convenience samples of individuals who have been in some type of treatment are used. Berkson's fallacy results when the associations found in studies of select samples are incorrectly presumed to apply to all alcoholics (i.e., including untreated alcoholics in the general population). In the current study, we examined whether treated and untreated alcoholics have similar early alcohol use histories by comparing abstinent alcoholics (treated and sober at least 6 months) with treatment-naive alcoholics (active drinkers). We studied 14 pairs of women and 25 pairs of men matched on the age at which they first met criteria for heavy alcohol use (women, 80 drinks per month; men, 100 drinks per month). The timeline follow-back interview method was used to gather retrospective alcohol use information. Alcohol dose and duration of use were subsequently computed for two intervals: (1) time between the person's first drink and date at which the person met criteria for heavy drinking and (2) period between when criteria for heavy drinking were met and current age of the treatment-naive person from each pair. During the period before the matching "heavy drinking" criteria were met, alcohol dose did not differ between groups. In the period after criteria for heavy alcohol use were met, in comparison with treatment-naive alcoholics, the treated alcoholics had higher average and peak alcohol doses. We rejected the hypothesis that the treatment-naive alcoholics and the treated alcoholics have similar alcohol use trajectories over time, with the treatment-naive sample simply being observed earlier in its alcohol use histories. Instead, we concluded that the two groups come from different populations with regard to alcohol use. In fact, the treated alcoholics had alcohol doses more than 50% higher than those of treatment-naive alcoholics in the years just after they began drinking heavily. This finding supports the suggestion that results from studies of alcoholics in treatment or after treatment (i.e., most studies of alcoholics) cannot be generalized to untreated individuals (who make up the majority of alcoholics).

Controlling for premorbid brain size in imaging studies: T1-derived cranium scaling factor vs. T2-derived intracranial vault volume

Intracranial vault (ICV) volume, obtained from T2-weighted magnetic resonance imaging (MRI), is generally used to estimate premorbid brain size in imaging studies. T1-weighted sequences lack the signal characteristics for ICV measurements [they have poor contrast at the outer boundary of sulcal cranium scaling factor (CSF)] but are valuable in imaging studies due to their excellent gray vs. white matter contrast. Smith et al. [NeuroImage 17 (2002) 479] suggested a T1-derived cranium scaling factor as an alternative control variable for premorbid brain size in cross-sectional studies. This index, which is computed using the SIENAX software, is a scaling factor comparing an individual's skull to a template skull derived from the Montreal Neurological Institute (MNI) average of 152 T1 studies (the MNI152). SIENAX computes coarsely defined estimates for the individual and MNI skulls rather than well-defined volumes. To test how well this approach would work as a control variable for premorbid brain size in cross-sectional studies, we compared the T1-derived cranium scaling factor to T2-derived ICV measurements in a sample of 92 individuals: 39 white males, 22 white females, and 31 African-American males, with an age range of 26-78 years. The correlation between T1- and T2-derived variables was 0.94 and did not differ across subject groups. The T1-derived cranium scaling factor accounted for a statistically significant portion (87%) of the variance of the T2-derived ICV measure and thus is a good surrogate for ICV measurement of premorbid brain size as a reference measure in MRI atrophy studies. Furthermore, neither race, sex, nor age accounted for any additional variance in ICV, indicating that neither race-, gender-, nor age-associated cranial bone thickness effects were present in this data set.

320EFFECT OF CYSTEAMINE DURING IN VITRO MATURATION ON FURTHER EMBRYONIC DEVELOPMENT AND POSTTHAW SURVIVAL OF IVP BOVINE EMBRYOS

The uptake of cysteamine by immature oocytes may facilitate the synthesis of glutathione (GSH) during in vitro maturation, as reported by Matos et al. (1995 Mol. Reprod. Dev. 42 432–436). GSH plays an important protective role in relation to reactive oxygen species generated by normal oxidative metabolism. This study investigated the effects of the presence of cysteamine during in vitro maturation on subsequent in vitro embryonic development and postthaw in vitro survival. Immature Cumulus-Oocyte-Complexes (COCs) were recovered from ovaries 6 to 8h after slaughter. COCs were matured in vitro for 22 to 24h in TCM199/FCS/LH/FSH supplemented either with or without cysteamine (0.1mM), Subsequently, matured oocytes were fertilized with frozen-thawed Percoll-separated semen and further cultured for seven days in SOFaaBSA. Morulae grade 1 (IETS) and blastocysts grades 1 and 2 (IETS) were frozen on Day 7 in 10% Glycerol using a conventional slow freezing procedure (Wagtendonk-de Leeuw et al. 1995 Cryobiology;; 32 157–167). In vitro survival was measured by rates of blastocyst formation and reexpansion at 24h and hatching/ed blastocysts at 72h in SOFaaBSA supplemented with 5% FCS. Results were analyzed by Chi-square analyses. The presence of cysteamine during in vitro maturation significantly affected the embryo production rate (19.4% and 24.0% for control and cysteamine at Day 7, respectively). The higher number of embryos at Day 7 was totally due to an increased number of blastocysts (Table 1); however, the distribution of embryos among the different quality grades was not affected. Addition of cysteamine did not affect the post thaw survival of the frozen/thawed embryos (85% v. 91% reexpansion and 33% v. 34% hatching/ed for control v. cysteamine, respectively). These results show that the presence of cysteamine during in vitro maturation, does affect further in vitro embryonic development, resulting in a higher embryo production rate. Embryo quality, expressed in morphological grades and postthaw survival rates, were not affected. A field trial will be conducted in order to confirm these results with ovum pick up-derived oocytes. Table 1 Effect of cysteamine during in vitro maturation on subsequent in vitro embryonic development of IVP bovine embryos (number of replicates: 5)