Scalable metadata environments (MDE): artistically impelled immersive environments for large-scale data exploration

NASA Astrophysics Data System (ADS)

West, Ruth G.; Margolis, Todd; Prudhomme, Andrew; Schulze, Jürgen P.; Mostafavi, Iman; Lewis, J. P.; Gossmann, Joachim; Singh, Rajvikram

2014-02-01

Scalable Metadata Environments (MDEs) are an artistic approach for designing immersive environments for large scale data exploration in which users interact with data by forming multiscale patterns that they alternatively disrupt and reform. Developed and prototyped as part of an art-science research collaboration, we define an MDE as a 4D virtual environment structured by quantitative and qualitative metadata describing multidimensional data collections. Entire data sets (e.g.10s of millions of records) can be visualized and sonified at multiple scales and at different levels of detail so they can be explored interactively in real-time within MDEs. They are designed to reflect similarities and differences in the underlying data or metadata such that patterns can be visually/aurally sorted in an exploratory fashion by an observer who is not familiar with the details of the mapping from data to visual, auditory or dynamic attributes. While many approaches for visual and auditory data mining exist, MDEs are distinct in that they utilize qualitative and quantitative data and metadata to construct multiple interrelated conceptual coordinate systems. These "regions" function as conceptual lattices for scalable auditory and visual representations within virtual environments computationally driven by multi-GPU CUDA-enabled fluid dyamics systems.

Cerebral arteriovenous malformation

MedlinePlus

AVM - cerebral; Arteriovenous hemangioma; Stroke - AVM; Hemorrhagic stroke - AVM ... The cause of cerebral AVM is unknown. An AVM occurs when arteries in the brain connect directly to nearby veins without having the ...

Operational Support for Instrument Stability through ODI-PPA Metadata Visualization and Analysis

NASA Astrophysics Data System (ADS)

Young, M. D.; Hayashi, S.; Gopu, A.; Kotulla, R.; Harbeck, D.; Liu, W.

2015-09-01

Over long time scales, quality assurance metrics taken from calibration and calibrated data products can aid observatory operations in quantifying the performance and stability of the instrument, and identify potential areas of concern or guide troubleshooting and engineering efforts. Such methods traditionally require manual SQL entries, assuming the requisite metadata has even been ingested into a database. With the ODI-PPA system, QA metadata has been harvested and indexed for all data products produced over the life of the instrument. In this paper we will describe how, utilizing the industry standard Highcharts Javascript charting package with a customized AngularJS-driven user interface, we have made the process of visualizing the long-term behavior of these QA metadata simple and easily replicated. Operators can easily craft a custom query using the powerful and flexible ODI-PPA search interface and visualize the associated metadata in a variety of ways. These customized visualizations can be bookmarked, shared, or embedded externally, and will be dynamically updated as new data products enter the system, enabling operators to monitor the long-term health of their instrument with ease.

Absolute Ethanol Embolization of Arteriovenous Malformations in the Periorbital Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Li-xin, E-mail: sulixin1975@126.com; Jia, Ren-Bing, E-mail: jrb19760517@hotmail.com; Wang, De-Ming, E-mail: wdmdeming@hotmail.com

2015-06-15

ObjectiveArteriovenous malformations (AVMs) involving the periorbital region are technically challenging clinical entities to manage. The purpose of the present study was to present our initial experience of ethanol embolization in a series of 16 patients with auricular AVMs and assess the outcomes of this treatment.MethodsTranscatheter arterial embolization and/or direct percutaneous puncture embolization were performed in the 16 patients. Pure or diluted ethanol was manually injected. The follow-up evaluations included physical examination and angiography at 1- to 6-month intervals.ResultsDuring the 28 ethanol embolization sessions, the amount of ethanol used ranged from 2 to 65 mL. The obliteration of ulceration, hemorrhage, pain, infection,more » pulsation, and bruit in most of the patients was obtained. The reduction of redness, swelling, and warmth was achieved in all the 16 patients, with down-staging of the Schobinger status for each patient. AVMs were devascularized 100 % in 3 patients, 76–99 % in 7 patients, and 50–75 % in 6 patients, according to the angiographic findings. The most common complications were necrosis and reversible blister. No permanent visual abnormality was found in any of the cases.ConclusionEthanol embolization is efficacious and safe in the treatment of AVMs in the periorbital region and has the potential to be accepted as the primary mode of therapy in the management of these lesions.« less

Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery.

PubMed

Bednarz, G; Downes, B; Werner-Wasik, M; Rosenwasser, R H

2000-03-15

This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17-2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73-99%). The mean MRA nidus volume was 2.4 cc (range 0. 6-5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20-1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.

Metadata Mapper: a web service for mapping data between independent visual analysis components, guided by perceptual rules

NASA Astrophysics Data System (ADS)

Rogowitz, Bernice E.; Matasci, Naim

2011-03-01

The explosion of online scientific data from experiments, simulations, and observations has given rise to an avalanche of algorithmic, visualization and imaging methods. There has also been enormous growth in the introduction of tools that provide interactive interfaces for exploring these data dynamically. Most systems, however, do not support the realtime exploration of patterns and relationships across tools and do not provide guidance on which colors, colormaps or visual metaphors will be most effective. In this paper, we introduce a general architecture for sharing metadata between applications and a "Metadata Mapper" component that allows the analyst to decide how metadata from one component should be represented in another, guided by perceptual rules. This system is designed to support "brushing [1]," in which highlighting a region of interest in one application automatically highlights corresponding values in another, allowing the scientist to develop insights from multiple sources. Our work builds on the component-based iPlant Cyberinfrastructure [2] and provides a general approach to supporting interactive, exploration across independent visualization and visual analysis components.

In vitro characteristics of endothelial cells prepared from human cerebral arteriovenous malformation lesions using a novel method.

PubMed

Hao, Q; Chen, X L; Ma, L; Ye, X; Wang, H; Wang, T T; Hu, Y; Zhao, Y L

2018-03-01

The cerebral arteriovenous malformation (cAVM) is a usual and continually unaware reason of heamorrhage and seizure. It contains of feeder arteries, drain veins and abnormal vessel nets. However, pathologic mechanisms of the development of cAVM are unknown. The purpose of this study was to explore a novel protocol to isolate, culture and passage endothelial cells (ECs) from human cAVM lesions. We developed a protocol for isolating and growing ECs from eight patients with cAVM. The tissues were microsurgically removed from cAVM lesion and were digested by 0.25% Trypsin-EDTA, and cultured in ECM medium. ECs were selected by FACS and confirmed their EC origin by immunocytochemistry of the basic expression patterns of CD31 and CD34. LDL-uptake and capillary tube formation were used to determine their functional features. The isolated cAVM-ECs exhibited contact inhibition of growth and appearance of rounded cobblestone. cAVM-ECs were CD31- and CD34-positive. In functional assays, cAVM-ECs were able to uptake LDL and form capillary tubes. cAVM-ECs from younger patients proliferated faster than that from elders, and cAVM-ECs were less stable than normal artery ECs. In addition, cAVM-ECs appeared to more easily transform into mesenchymal cells than normal artery ECs. Using the protocol, isolated cAVM-ECs are stably established, and retain their endothelial phenotypes. These cAVM-ECs may provide a biological tool to examine molecular phenotypes and mechanisms responsible for human cAVM. Copyright © 2017 Elsevier Inc. All rights reserved.

Procedure for the Isolation of Endothelial Cells from Human Cerebral Arteriovenous Malformation (cAVM) Tissues.

PubMed

Hao, Qiang; Chen, Xiao-Lin; Ma, Li; Wang, Tong-Tong; Hu, Yue; Zhao, Yuan-Li

2018-01-01

In this study, we successfully established a stable method for the isolation of endothelial cells (ECs) from human cerebral arteriovenous malformation (cAVM) tissues. Despite human cAVM tissues having a minor population of ECs, they play an important role in the manifestation and development of cAVM as well as in hemorrhagic stroke and thrombogenesis. To characterize and understand the biology of ECs in human cAVM (cAVM-ECs), methods for the isolation and purification of these cells are necessary. We have developed this method to reliably obtain pure populations of ECs from cAVMs. To obtain pure cell populations, cAVM tissues were mechanically and enzymatically digested and the resulting single cAVM-ECs suspensions were then labeled with antibodies of specific cell antigens and selected by flow cytometry. Purified ECs were detected using specific makers of ECs by immunostaining and used to study different cellular mechanisms. Compared to the different methods of isolating ECs from tissues, we could isolate ECs from cAVMs confidently, and the numbers of cAVM-ECs harvested were almost similar to the amounts present in vessel components. In addition to optimizing the protocol for isolation of ECs from human cAVM tissues, the protocol could also be applied to isolate ECs from other human neurovascular-diseased tissues. Depending on the tissues, the whole procedure could be completed in about 20 days.

Thalidomide Reduces Hemorrhage of Brain Arteriovenous Malformations in a Mouse Model.

PubMed

Zhu, Wan; Chen, Wanqiu; Zou, Dingquan; Wang, Liang; Bao, Chen; Zhan, Lei; Saw, Daniel; Wang, Sen; Winkler, Ethan; Li, Zhengxi; Zhang, Meng; Shen, Fanxia; Shaligram, Sonali; Lawton, Michael; Su, Hua

2018-05-01

Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current treatments for bAVM are all associated with considerable risks. There is no safe method to prevent bAVM hemorrhage. Thalidomide reduces nose bleeding in patients with hereditary hemorrhagic telangiectasia, an inherited disorder characterized by vascular malformations. In this study, we tested whether thalidomide and its less toxic analog, lenalidomide, reduce bAVM hemorrhage using a mouse model. bAVMs were induced through induction of brain focal activin-like kinase 1 ( Alk1 , an AVM causative gene) gene deletion and angiogenesis in adult Alk1 -floxed mice. Thalidomide was injected intraperitoneally twice per week for 6 weeks, starting either 2 or 8 weeks after AVM induction. Lenalidomide was injected intraperitoneally daily starting 8 weeks after AVM induction for 6 weeks. Brain samples were collected at the end of the treatments for morphology, mRNA, and protein analyses. The influence of Alk1 downregulation on PDGFB (platelet-derived growth factor B) expression was also studied on cultured human brain microvascular endothelial cells. The effect of PDGFB in mural cell recruitment in bAVM was explored by injection of a PDGFB overexpressing lentiviral vector to the mouse brain. Thalidomide or lenalidomide treatment reduced the number of dysplastic vessels and hemorrhage and increased mural cell (vascular smooth muscle cells and pericytes) coverage in the bAVM lesion. Thalidomide reduced the burden of CD68 + cells and the expression of inflammatory cytokines in the bAVM lesions. PDGFB expression was reduced in ALK1-knockdown human brain microvascular endothelial cells and in mouse bAVM lesion. Thalidomide increased Pdgfb expression in bAVM lesion. Overexpression of PDGFB mimicked the effect of thalidomide. Thalidomide and lenalidomide improve mural cell coverage of bAVM vessels and reduce bAVM hemorrhage, which is likely through upregulation of Pdgfb expression. © 2018 American Heart Association, Inc.

Factors Associated With Proximal Intracranial Aneurysms to Brain Arteriovenous Malformations: A Prospective Cohort Study.

PubMed

Morgan, Michael Kerin; Alsahli, Khalid; Wiedmann, Markus; Assaad, Nazih N; Heller, Gillian Z

2016-06-01

The risk of hemorrhage from a brain arteriovenous malformation (bAVM) is increased when an associated proximal intracranial aneurysm (APIA) is present. Identifying factors that are associated with APIA may influence the prediction of hemorrhage in patients with bAVM. To identify patient- and bAVM-specific factors associated with APIA. We analyzed a prospective database of bAVMs for factors associated with the presence of APIA. Factors analyzed included age, sex, bAVM size, aneurysm size, circulation contributing to the bAVM, location of the aneurysm, deep venous drainage, and Spetzler-Ponce categories. Multiple logistic regression was performed to identify an association with APIA. Of 753 cases of bAVM with complete angiographic surveillance, 67 (9%) were found to have APIA. Older age (continuous variable; odds ratio, 1.04; 95% confidence interval, 1.02-1.05) and posterior circulation supply to the bAVM (odds ratio, 2.29; 95% confidence interval, 1.32-3.99) were factors associated with increased detection of APIA. The association of posterior circulation-supplied bAVM was not due to infratentorial bAVM location because 72% of posterior circulation APIAs were supplying supratentorial bAVM. APIAs appear to develop with time, as evident from the increased age for those with APIAs. Furthermore, they were more likely present in bAVMs supplied by the posterior circulation. This may be due to a difference in hemodynamic stress. APIA, associated proximal intracranial aneurysmbAVM, brain arteriovenous malformationDSA, digital subtraction angiographySMG, Spetzler-Martin gradeSPC, Spetzler-Ponce category.

Development of three-dimensional brain arteriovenous malformation model for patient communication and young neurosurgeon education.

PubMed

Dong, Mengqi; Chen, Guangzhong; Qin, Kun; Ding, Xiaowen; Zhou, Dong; Peng, Chao; Zeng, Shaojian; Deng, Xianming

2018-01-15

Rapid prototyping technology is used to fabricate three-dimensional (3D) brain arteriovenous malformation (AVM) models and facilitate presurgical patient communication and medical education for young surgeons. Two intracranial AVM cases were selected for this study. Using 3D CT angiography or 3D rotational angiography images, the brain AVM models were reconstructed on personal computer and the rapid prototyping process was completed using a 3D printer. The size and morphology of the models were compared to brain digital subtraction arteriography of the same patients. 3D brain AVM models were used for preoperative patient communication and young neurosurgeon education. Two brain AVM models were successfully produced. By neurosurgeons' evaluation, the printed models have high fidelity with the actual brain AVM structures of the patients. The patient responded positively toward the brain AVM model specific to himself. Twenty surgical residents from residency programs tested the brain AVM models and provided positive feedback on their usefulness as educational tool and resemblance to real brain AVM structures. Patient-specific 3D printed models of brain AVM can be constructed with high fidelity. 3D printed brain AVM models are proved to be helpful in preoperative patient consultation, surgical planning and resident training.

Pathogenesis of arteriovenous malformations in the absence of endoglin.

PubMed

Mahmoud, Marwa; Allinson, Kathleen R; Zhai, Zhenhua; Oakenfull, Rachael; Ghandi, Pranita; Adams, Ralf H; Fruttiger, Marcus; Arthur, Helen M

2010-04-30

Arteriovenous malformations (AVMs) result in anomalous direct blood flow between arteries and veins, bypassing the normal capillary bed. Depending on size and location, AVMs may lead to severe clinical effects including systemic cyanosis (pulmonary AVMs), hemorrhagic stroke (cerebral AVMs) and high output cardiac failure (hepatic AVMs). The factors leading to AVM formation are poorly understood, but patients with the familial disease hereditary hemorrhagic telangiectasia (HHT) develop AVMs at high frequency. As most HHT patients have mutations in ENG (endoglin) or ACVRL1 (activin receptor-like kinase 1), a better understanding of the role of these genes in vascular development is likely to reveal the etiology of AVM formation. Using a mouse with a conditional mutation in the Eng gene, we investigated the sequence of abnormal cellular events occurring during development of an AVM. In the absence of endoglin, subcutaneous Matrigel implants in adult mice were populated by reduced numbers of new blood vessels compared with controls, and resulted in local venous enlargement (venomegaly). To investigate abnormal vascular responses in more detail, we turned to the more readily accessible vasculature of the neonatal retina. Endoglin-deficient retinas exhibited delayed remodeling of the capillary plexus, increased proliferation of endothelial cells and localized AVMs. Muscularization of the resulting arteriovenous shunts appeared to be a secondary response to increased blood flow. AVMs develop when an angiogenic stimulus is combined with endoglin depletion. Moreover, AVM formation appears to result from the combination of delayed vascular remodeling and an inappropriate endothelial cell proliferation response in the absence of endoglin.

A Modified Radiosurgery-Based Arteriovenous Malformation Grading Scale and Its Correlation With Outcomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wegner, Rodney E.; Oysul, Kaan; Pollock, Bruce E.

Purpose: The Pittsburgh radiosurgery-based arteriovenous malformation (AVM) grading scale was developed to predict patient outcomes after radiosurgery and was later modified with location as a two-tiered variable (deep vs. other). The purpose of this study was to test the modified radiosurgery-based AVM score in a separate set of AVM patients managed with radiosurgery. Methods and Materials: The AVM score is calculated as follows: AVM score = (0.1)(volume, cc) + (0.02)(age, years) + (0.5)(location; frontal/temporal/parietal/occipital/intraventricular/corpus callosum/cerebellar = 0, basal ganglia/thalamus/brainstem = 1). Testing of the modified system was performed on 293 patients having AVM radiosurgery from 1992 to 2004 at themore » University of Pittsburgh with dose planning based on a combination of stereotactic angiography and MRI. The median patient age was 38 years, the median AVM volume was 3.3 cc, and 57 patients (19%) had deep AVMs. The median modified AVM score was 1.25. The median patient follow-up was 39 months. Results: The modified AVM scale correlated with the percentage of patients with AVM obliteration without new deficits ({<=}1.00, 62%; 1.01-1.50, 51%; 1.51-2.00, 53%; and >2.00, 32%; F = 11.002, R{sup 2} = 0.8117, p = 0.001). Linear regression also showed a statistically significant correlation between outcome and dose prescribed to the margin (F = 25.815, p <0.001). Conclusions: The modified radiosurgery-based AVM grading scale using location as a two-tiered variable correlated with outcomes when tested on a cohort of patients who underwent both angiography and MRI for dose planning. This system can be used to guide choices among observation, endovascular, surgical, and radiosurgical management strategies for individual AVM patients.« less

Augmented reality in neurovascular surgery: feasibility and first uses in the operating room.

PubMed

Kersten-Oertel, Marta; Gerard, Ian; Drouin, Simon; Mok, Kelvin; Sirhan, Denis; Sinclair, David S; Collins, D Louis

2015-11-01

The aim of this report is to present a prototype augmented reality (AR) intra-operative brain imaging system. We present our experience of using this new neuronavigation system in neurovascular surgery and discuss the feasibility of this technology for aneurysms, arteriovenous malformations (AVMs), and arteriovenous fistulae (AVFs). We developed an augmented reality system that uses an external camera to capture the live view of the patient on the operating room table and to merge this view with pre-operative volume-rendered vessels. We have extensively tested the system in the laboratory and have used the system in four surgical cases: one aneurysm, two AVMs and one AVF case. The developed AR neuronavigation system allows for precise patient-to-image registration and calibration of the camera, resulting in a well-aligned augmented reality view. Initial results suggest that augmented reality is useful for tailoring craniotomies, localizing vessels of interest, and planning resection corridors. Augmented reality is a promising technology for neurovascular surgery. However, for more complex anomalies such as AVMs and AVFs, better visualization techniques that allow one to distinguish between arteries and veins and determine the absolute depth of a vessel of interest are needed.

Interactive Visualization Systems and Data Integration Methods for Supporting Discovery in Collections of Scientific Information

DTIC Science & Technology

2011-05-01

iTunes illustrate the difference between the centralized approach of digital library systems and the distributed approach of container file formats...metadata in a container file format. Apple’s iTunes uses a centralized metadata approach and allows users to maintain song metadata in a single...one iTunes library to another the metadata must be copied separately or reentered in the new library. This demonstrates the utility of storing metadata

The Value of Data and Metadata Standardization for Interoperability in Giovanni Or: Why Your Product's Metadata Causes Us Headaches!

NASA Technical Reports Server (NTRS)

Smit, Christine; Hegde, Mahabaleshwara; Strub, Richard; Bryant, Keith; Li, Angela; Petrenko, Maksym

2017-01-01

Giovanni is a data exploration and visualization tool at the NASA Goddard Earth Sciences Data Information Services Center (GES DISC). It has been around in one form or another for more than 15 years. Giovanni calculates simple statistics and produces 22 different visualizations for more than 1600 geophysical parameters from more than 90 satellite and model products. Giovanni relies on external data format standards to ensure interoperability, including the NetCDF CF Metadata Conventions. Unfortunately, these standards were insufficient to make Giovanni's internal data representation truly simple to use. Finding and working with dimensions can be convoluted with the CF Conventions. Furthermore, the CF Conventions are silent on machine-friendly descriptive metadata such as the parameter's source product and product version. In order to simplify analyzing disparate earth science data parameters in a unified way, we developed Giovanni's internal standard. First, the format standardizes parameter dimensions and variables so they can be easily found. Second, the format adds all the machine-friendly metadata Giovanni needs to present our parameters to users in a consistent and clear manner. At a glance, users can grasp all the pertinent information about parameters both during parameter selection and after visualization.

Brain Arteriovenous Malformation Pathogenesis: A Response-to-Injury Paradigm

PubMed Central

Kim, Helen; Su, Hua; Weinsheimer, Shantel; Pawlikowska, Ludmila; Young, William L.

2011-01-01

Brain arteriovenous malformations (AVMs) are a rare but important cause of intracranial hemorrhage (ICH) in young adults. In this paper, we review both human and animal studies of brain AVM, focusing on the: (1) natural history of AVM hemorrhage; (2) genetic and expression studies of AVM susceptibility and hemorrhage; and (3) strategies for development of a brain AVM model in adult mice. These data target various mechanisms which must act in concert to regulate normal angiogenic response to injury. Based on the various lines of evidence reviewed in this paper, we propose a “response-to-injury” model of brain AVM pathogenesis. PMID:21725736

The "focus on aneurysm" principle: Classification and surgical principles of management of concurrent arterial aneurysm with arteriovenous malformation causing intracranial hemorrhage.

PubMed

Jha, Vikas; Behari, Sanjay; Jaiswal, Awadhesh K; Bhaisora, Kamlesh Singh; Shende, Yogesh P; Phadke, Rajendra V

2016-01-01

Concurrent arterial aneurysms (AAs) occurring in 2.7-16.7% patients harboring an arteriovenous malformation (AVM) aggravate the risk of intracranial hemorrhage. We evaluate the variations of aneurysms simultaneously coexisting with AVMs. A classification-based management strategy and an abbreviated nomenclature that describes their radiological features is also proposed. Tertiary care academic institute. Test of significance applied to determine the factors causing rebleeding in the groups of patients with concurrent AVM and aneurysm and those with only AVMs. Sixteen patients (5 with subarachnoid hemorrhage and 11 with intracerebral/intraventricular hemorrhage; 10 with low flow [LF] and 6 with high flow [HF] AVMs) underwent radiological assessment of Spetzler Martin (SM) grading and flow status of AA + AVM. Their modified Rankin's score (mRS) at admission was compared with their follow-up (F/U) score. Pre-operative mRS was 0 in 5, 2 in 6, 3 in 1, 4 in 3 and 5 in 1; and, SM grade I in 5, II in 3, III in 3, IV in 4 and V in 1 patients, respectively. AA associated AVMs were classified as: (I) Flow-related proximal (n = 2); (II) flow-related distal (n = 3); (III) intranidal (n = 5); (IV) extra-intranidal (n = 2); (V) remote major ipsilateral (n = 1); (VI) remote major contralateral (n = 1); (VII) deep perforator related (n = 1); (VIII) superficial (n = 1); and (IX) distal (n = 0). Their treatment strategy included: Flow related AA, SM I-III LF AVM: aneurysm clipping with AVM excision; nidal-extranidal AA, SM I-III LF AVM: Excision or embolization of both AA + AVM; nidal-extranidal and perforator-related AA, SM IV-V HF AVM: Only endovascular embolization or radiosurgery. Surgical decision-making for remote AA took into account their ipsilateral/contralateral filling status and vessel dominance; and, for AA associated with SM III HF AVM, it varied in each patient based on diffuseness of AVM nidus, flow across arteriovenous fistula and eloquence of cortex. Follow up (F/U) (23.29 months; range: 1.5-69 months) mRS scores were 0 in 12, 2 in 2, 3 in 1 and 6 in 1 patients, respectively. Patients with intracranial AVMs should be screened for concurrent AAs. Further grading, management protocols and prognostication should particularly "focus on the aneurysm."

Gamma Knife Radiosurgery for Pediatric Arteriovenous Malformations: A Canadian Experience.

PubMed

Zeiler, Fred A; Janik, Maciej K; McDonald, Patrick J; Kaufmann, Anthony M; Fewer, Derek; Butler, Jim; Schroeder, Garry; West, Michael

2016-01-01

Gamma Knife (GK) radiosurgery for pediatric arteriovenous malformations (AVM) of the brain presents a non-invasive treatment option. We report our institutional experience with GK for pediatric AVMs. We performed a retrospective review of all pediatric patients treated with GK for cerebral AVMs at our institution from November 2003 up to and including September 2014. Patient demographics, AVM characteristics, treatment parameters and AVM responses were recorded. Nineteen patients were treated, with 4 lost to follow-up. The mean age was 14.2 years (range. 7-18 years), with 10 being males (52.6%). The mean AVM diameter and volume were 2.68 cm and 3.10 cm3 respectively. The mean Spetzler-Martin (SM) and Pollock grades of the treated AVMs were 2.4 and 0.99 respectively. The mean follow-up was 62 months. All AVMs treated demonstrated a response on follow-up imaging. Nine of 15 (60.0%) patients displayed obliteration of their AVMs. Nine of 11 patients with a minimum of 3 years follow-up (81.8%) displayed obliteration, with SM and Pollock grades correlating to the chance of obliteration in this group. Two patients developed post-GK edema requiring short course dexamethasone therapy. No other major complications occurred. No permanent complications occurred. GK radiosurgery for pediatric AVMs offers a safe and effective treatment option, with low permanent complication rates during early follow-up.

Pathogen metadata platform: software for accessing and analyzing pathogen strain information.

PubMed

Chang, Wenling E; Peterson, Matthew W; Garay, Christopher D; Korves, Tonia

2016-09-15

Pathogen metadata includes information about where and when a pathogen was collected and the type of environment it came from. Along with genomic nucleotide sequence data, this metadata is growing rapidly and becoming a valuable resource not only for research but for biosurveillance and public health. However, current freely available tools for analyzing this data are geared towards bioinformaticians and/or do not provide summaries and visualizations needed to readily interpret results. We designed a platform to easily access and summarize data about pathogen samples. The software includes a PostgreSQL database that captures metadata useful for disease outbreak investigations, and scripts for downloading and parsing data from NCBI BioSample and BioProject into the database. The software provides a user interface to query metadata and obtain standardized results in an exportable, tab-delimited format. To visually summarize results, the user interface provides a 2D histogram for user-selected metadata types and mapping of geolocated entries. The software is built on the LabKey data platform, an open-source data management platform, which enables developers to add functionalities. We demonstrate the use of the software in querying for a pathogen serovar and for genome sequence identifiers. This software enables users to create a local database for pathogen metadata, populate it with data from NCBI, easily query the data, and obtain visual summaries. Some of the components, such as the database, are modular and can be incorporated into other data platforms. The source code is freely available for download at https://github.com/wchangmitre/bioattribution .

Arteriovenous malformations of the uterus.

PubMed

Cura, M; Martinez, N; Cura, A; Dalsaso, T J; Elmerhi, F

2009-09-01

Arterial venous malformations (AVM) of the uterus are uncommon entities and should be considered in patients who present with profuse genital bleeding. There are two types of uterine AVM: acquired and congenital. Acquired uterine AVMs are conformed by communications between the uterine arteries and the myometrial veins, and are caused by an iatrogenic event or a pathological condition. Congenital AVMs are the result of abnormal development of primitive vessels that result in connections between pelvic arteries and veins in the uterus without an interconnecting capillary bed. Ultrasonography is a noninvasive diagnostic method able to demonstrate and characterize AVMs of the uterus. AVM in the pelvis may be noted incidentally by computed tomography (CT) of the pelvis, and magnetic resonance imaging (MRI) is frequently used to confirm and further characterize the sonographic findings of uterine AVM. Catheter angiography and embolization are very effective in defining the vascular anatomy and treating uterine vascular abnormalities.

Clinical presentation and treatment paradigms of brain arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia.

PubMed

Gamboa, Nicholas T; Joyce, Evan J; Eli, Ilyas; Park, Min S; Taussky, Philipp; Schmidt, Richard H; McDonald, Jamie; Whitehead, Kevin J; Kalani, M Yashar S

2018-05-01

Hereditary hemorrhagic telangiectasia (HHT) is characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectases, and multisystem arteriovenous malformations (AVMs). Brain AVMs typically present at birth and are identified in approximately 10-20% of patients with HHT. A retrospective review was undertaken of all HHT patients with known single or multiple brain AVMs treated at our institution. Thirty-nine patients with brain AVM(s) were diagnosed with HHT. Most patients presented with at least one Curaçao criterion. A total of 78 brain AVMs were identified in 39 patients. Two-thirds of patients had solitary brain AVMs, whereas 33% of patients harbored at least two lesions (range: 2-16). Brain AVMs of the supratentorial cerebral hemispheres comprised 83% of all lesions, whereas infratentorial lesions accounted for only 17%. Of the 55 brain AVMs assigned Spetzler-Martin grading, the majority of patients were Grade 1 (73%), and 23% and 4% were Grades 2 and 3, respectively. Patients were treated with surgery alone (51%), embolization alone (6%), embolization followed by surgery (9%), stereotactic radiosurgery (11%), stereotactic radiosurgery followed by surgery (3%), or observation (20%). Of patients who underwent genetic analysis, 62% possessed mutations in ENG (HHT type 1), whereas 38% had mutations in ACVRL1 (HHT type 2). This robust patient cohort of brain AVMs in 39 patients with HHT advances the collective understanding of this disease's varied presentation, diagnostic workup, genetic underpinnings, and available treatment options. Copyright © 2018. Published by Elsevier Ltd.

Difference of language cortex reorganization between cerebral arteriovenous malformations, cavernous malformations, and gliomas: a functional MRI study.

PubMed

Deng, Xiaofeng; Xu, Long; Zhang, Yan; Wang, Bo; Wang, Shuo; Zhao, Yuanli; Cao, Yong; Zhang, Dong; Wang, Rong; Ye, Xun; Wu, Jun; Zhao, Jizong

2016-04-01

The authors attempted to demonstrate the difference in language cortex reorganization between cerebral malformations (AVMs), cavernous malformations (CMs), and gliomas by blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. Clinical and imaging data of 27 AVM patients (AVM-L group), 29 CM patients (CM-L group), and 20 glioma patients (Glioma-L group) were retrospectively reviewed, with lesions overlying the left inferior frontal gyrus (Broca area). As a control, patients with lesions involving the right inferior frontal gyrus were also enrolled, including 14 AVM patients (AVM-R group), 20 CM patients (CM-R group), and 14 glioma patients (Glioma-R group). All patients were right-handed. Lateralization indices (LI) of BOLD signal activations were calculated separately for Broca and Wernicke areas. In AVM-L group, right-sided lateralization of BOLD signals was observed in 10 patients (37.0%), including 6 in the Broca area alone, 1 in the Wernicke area alone, and 3 in both areas. Three patients (10.3%) of CM-L group showed right-sided lateralization in both Broca and Wernicke areas, and 1 patient (5.0%) of Glioma-L group had right-sided lateralization in the Wernicke area alone. A significant difference of right-sided lateralization was observed between the AVM-L group and CM-L group (P = 0.018) and also between the AVM-L group and Glioma-L group (P = 0.027). No patient in AVM-R, CM-R, or Glioma-R groups showed right-sided lateralization. Language cortex reorganization may occur in AVM, CM, and glioma patients when the traditional language cortex was involved by lesions, but the potential of reorganization for CM and glioma patients seems to be insufficient compared with AVM patients.

Onyx(®) in endovascular treatment of cerebral arteriovenous malformations - a review.

PubMed

Szajner, Maciej; Roman, Tomasz; Markowicz, Justyna; Szczerbo-Trojanowska, Małgorzata

2013-07-01

Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. In most cases, the disorder may be asymptomatic. The objective of endovascular AVM treatment is set individually for each case upon consultations with a neurosurgeon and a neurologist. The endpoint of the treatment should consist in prevention of AVM bleeding in a management procedure characterized by a significantly lower risk of complications as compared to the natural history of AVM. Endovascular interventions within AVM may include curative exclusion of AVM from circulation, embolization adjuvant to resection or radiation therapy, targeted closure of a previously identified bleeding site as well as palliative embolization. Onyx was first described in the 1990s. It is a non-adhesive and radiolucent compound. Onyx-based closure of the lumen of the targeted vessel is obtained by means of precipitation. The process is enhanced peripherally to the main flux of the injected mixture. This facilitates angiographic monitoring of embolization at any stage. The degree of lumen closure is associated with the location of the vessel. Supratentorial and cortical locations are most advantageous. Dense and plexiform structure of AVM nidus as well as a low number of supplying vessels and a single superficial drainage vein are usually advantageous for Onyx administration. Unfavorable factors include nidus drainage into multiple compartments as well as multiarterial supply of the AVM, particularly from meningeal arteries, en-passant arteries or perforating feeders. Onyx appears to be a safe and efficient material for embolization of cerebral AVMs, also in cases of intracranial bleeding associated with AVM. Curative embolization of small cerebral AVMs is an efficient and safe alternative to neurosurgical and radiosurgical methods. Careful angiographic assessment of individual arteriovenous malformations should be performed before each Onyx administration.

Onyx® in endovascular treatment of cerebral arteriovenous malformations – a review

PubMed Central

Szajner, Maciej; Roman, Tomasz; Markowicz, Justyna; Szczerbo-Trojanowska, Małgorzata

2013-01-01

Summary Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. In most cases, the disorder may be asymptomatic. The objective of endovascular AVM treatment is set individually for each case upon consultations with a neurosurgeon and a neurologist. The endpoint of the treatment should consist in prevention of AVM bleeding in a management procedure characterized by a significantly lower risk of complications as compared to the natural history of AVM. Endovascular interventions within AVM may include curative exclusion of AVM from circulation, embolization adjuvant to resection or radiation therapy, targeted closure of a previously identified bleeding site as well as palliative embolization. Onyx was first described in the 1990s. It is a non-adhesive and radiolucent compound. Onyx-based closure of the lumen of the targeted vessel is obtained by means of precipitation. The process is enhanced peripherally to the main flux of the injected mixture. This facilitates angiographic monitoring of embolization at any stage. The degree of lumen closure is associated with the location of the vessel. Supratentorial and cortical locations are most advantageous. Dense and plexiform structure of AVM nidus as well as a low number of supplying vessels and a single superficial drainage vein are usually advantageous for Onyx administration. Unfavorable factors include nidus drainage into multiple compartments as well as multiarterial supply of the AVM, particularly from meningeal arteries, en-passant arteries or perforating feeders. Onyx appears to be a safe and efficient material for embolization of cerebral AVMs, also in cases of intracranial bleeding associated with AVM. Curative embolization of small cerebral AVMs is an efficient and safe alternative to neurosurgical and radiosurgical methods. Careful angiographic assessment of individual arteriovenous malformations should be performed before each Onyx administration. PMID:24115958

Testing the radiosurgery-based arteriovenous malformation score and the modified Spetzler-Martin grading system to predict radiosurgical outcome.

PubMed

Andrade-Souza, Yuri M; Zadeh, Gelareh; Ramani, Meera; Scora, Daryl; Tsao, May N; Schwartz, Michael L

2005-10-01

The aim of this study was to validate the radiosurgery-based arteriovenous malformation (AVM) score and the modified Spetzler-Martin grading system to predict radiosurgical outcome. One hundred thirty-six patients with brain AVMs were randomly selected. These patients had undergone a linear accelerator radiosurgical procedure at a single center between 1989 and 2000. Patients were divided into four groups according to an AVM score, which was calculated from the lesion volume, lesion location, and patient age (Group 1, AVM score <1; Group 2, AVM score 1-1.49; Group 3, AVM score 1.5-2; and Group 4, AVM score >2). Patients with a Spetzler-Martin Grade III AVM were divided into Grades IIIA (lesion >3 cm) and IIIB (lesion <3 cm). Sixty-two female (45.6%) and 74 male (54.4%) patients with a median age of 37.5 years (mean 37.5 years, range 5-77 years) were followed up for a median of 40 months. The median tumor margin dose was 15 Gy (mean 17.23 Gy, range 15-25 Gy). The proportions of excellent outcomes according to the AVM score were as follows: 91.7% for Group 1, 74.1% for Group 2, 60% for Group 3, and 33.3% for Group 4 (chi-square test, degrees of freedom (df) = 3, p < 0.001). Based on the modified Spetzler-Martin system, Grade I lesions had 88.9% excellent results; Grade II, 69.6%; Grade IIIB, 61.5%; and Grades IIIA and IV, 44.8% (chi-square test, df = 3, p = 0.047). The radiosurgery-based AVM score can be used accurately to predict excellent results following a single radiosurgical treatment for AVM. The modified Spetzler-Martin system can also predict radiosurgical results for AVMs, thus making it possible to use this system while deciding between surgery and radiosurgery.

The “focus on aneurysm” principle: Classification and surgical principles of management of concurrent arterial aneurysm with arteriovenous malformation causing intracranial hemorrhage

PubMed Central

Jha, Vikas; Behari, Sanjay; Jaiswal, Awadhesh K.; Bhaisora, Kamlesh Singh; Shende, Yogesh P.; Phadke, Rajendra V.

2016-01-01

Context: Concurrent arterial aneurysms (AAs) occurring in 2.7-16.7% patients harboring an arteriovenous malformation (AVM) aggravate the risk of intracranial hemorrhage. Aim: We evaluate the variations of aneurysms simultaneously coexisting with AVMs. A classification-based management strategy and an abbreviated nomenclature that describes their radiological features is also proposed. Setting: Tertiary care academic institute. Statistics: Test of significance applied to determine the factors causing rebleeding in the groups of patients with concurrent AVM and aneurysm and those with only AVMs. Subjects and Methods: Sixteen patients (5 with subarachnoid hemorrhage and 11 with intracerebral/intraventricular hemorrhage; 10 with low flow [LF] and 6 with high flow [HF] AVMs) underwent radiological assessment of Spetzler Martin (SM) grading and flow status of AA + AVM. Their modified Rankin's score (mRS) at admission was compared with their follow-up (F/U) score. Results: Pre-operative mRS was 0 in 5, 2 in 6, 3 in 1, 4 in 3 and 5 in 1; and, SM grade I in 5, II in 3, III in 3, IV in 4 and V in 1 patients, respectively. AA associated AVMs were classified as: (I) Flow-related proximal (n = 2); (II) flow-related distal (n = 3); (III) intranidal (n = 5); (IV) extra-intranidal (n = 2); (V) remote major ipsilateral (n = 1); (VI) remote major contralateral (n = 1); (VII) deep perforator related (n = 1); (VIII) superficial (n = 1); and (IX) distal (n = 0). Their treatment strategy included: Flow related AA, SM I-III LF AVM: aneurysm clipping with AVM excision; nidal-extranidal AA, SM I-III LF AVM: Excision or embolization of both AA + AVM; nidal-extranidal and perforator-related AA, SM IV-V HF AVM: Only endovascular embolization or radiosurgery. Surgical decision-making for remote AA took into account their ipsilateral/contralateral filling status and vessel dominance; and, for AA associated with SM III HF AVM, it varied in each patient based on diffuseness of AVM nidus, flow across arteriovenous fistula and eloquence of cortex. Follow up (F/U) (23.29 months; range: 1.5-69 months) mRS scores were 0 in 12, 2 in 2, 3 in 1 and 6 in 1 patients, respectively. Conclusions: Patients with intracranial AVMs should be screened for concurrent AAs. Further grading, management protocols and prognostication should particularly “focus on the aneurysm.” PMID:27366251

Superficial middle cerebral vein connection to the cavernous sinus is not infrequent in brain arteriovenous malformations: an argument against their congenital origin?

PubMed

Shotar, Eimad; Guédon, Alexis; Sourour, Nader; Di Maria, Federico; Gabrieli, Joseph; Nouet, Aurélien; Chiras, Jacques; Clarençon, Frédéric

2016-07-01

The aim of this study was to test the hypothesis that the superficial middle cerebral vein (SMCV) is frequently absent or fails to connect with the cavernous sinus (CS) in the presence of brain arteriovenous malformations (AVMs), a frequently reported argument for the congenital origin of brain AVMs. The SMCV was retrospectively compared between patients with a brain AVM and a control group. The presence or absence of the SMCV, its direct or indirect connection to the CS and its termination in a laterocavernous sinus (LCS), paracavernous sinus (PCS), or directly in the CS was studied on digital subtraction angiography. One hundred twenty-five left or right side carotid angiograms from 70 patients with a brain AVM were compared to 125 angiograms from 74 controls. The SMCV was present in 88 (70.4 %) cases in the brain AVM group and 96 (76.8 %) cases in controls (p = 0.25). The SMCV was connected directly or indirectly to the CS in 65 (52 %) cases in the brain AVM group and 65 (52 %) cases in controls (p = 1). When comparing the subgroup of carotid angiograms ipsilateral to a supratentorial AVM, no statistically significant difference was found with controls. In three of six cases in which a SMCV drained an AVM, the vein terminated directly or indirectly in the CS. No difference of SMCV presence and direct or indirect connection to the CS was found between patients with AVM and a control group. SMCV anatomy does not support the congenital origin of brain AVMs.

Seizure risk with AVM treatment or conservative management: prospective, population-based study.

PubMed

Josephson, Colin B; Bhattacharya, Jo J; Counsell, Carl E; Papanastassiou, Vakis; Ritchie, Vaughn; Roberts, Richard; Sellar, Robin; Warlow, Charles P; Al-Shahi Salman, Rustam

2012-08-07

To compare the risk of epileptic seizures in adults during conservative management or following invasive treatment for a brain arteriovenous malformation (AVM). We used annual general practitioner follow-up, patient questionnaires, and medical records surveillance to quantify the 5-year risk of seizures and the chances of achieving 2-year seizure freedom for adults undergoing AVM treatment compared to adults managed conservatively in a prospective, population-based observational study of adults in Scotland, newly diagnosed with an AVM in 1999-2003. We identified 229 adults with a new diagnosis of an AVM, of whom two-thirds received AVM treatment (154/229; 67%) during 1,862 person-years of follow-up (median completeness of follow-up 97%). There was no significant difference in the proportions with a first or recurrent seizure over 5 years following AVM treatment, compared to the first 5 years following clinical presentation in conservatively managed adults, in analyses stratified by mode of presentation (intracerebral hemorrhage, 35% vs 26%, p = 0.5; seizure, 67% vs 72%, p = 0.6; incidental, 21% vs 10%, p = 0.4). For patients with epilepsy, the chances of achieving 2-year seizure freedom during 5-year follow-up were similar following AVM treatment (n = 39; 52%, 95% confidence interval [CI] 36% to 68%) or conservative management (n = 21; 57%, 95% CI 35% to 79%; p = 0.7). In this observational study, there was no difference in the 5-year risk of seizures with AVM treatment or conservative management, irrespective of whether the AVM had presented with hemorrhage or epileptic seizures.

Identification of a rare BMP pathway mutation in a non-syndromic human brain arteriovenous malformation via exome sequencing.

PubMed

Walcott, Brian P; Winkler, Ethan A; Zhou, Sirui; Birk, Harjus; Guo, Diana; Koch, Matthew J; Stapleton, Christopher J; Spiegelman, Dan; Dionne-Laporte, Alexandre; Dion, Patrick A; Kahle, Kristopher T; Rouleau, Guy A; Lawton, Michael T

2018-01-01

Brain arteriovenous malformations (AVMs) are abnormal connections between arteries and veins that can result in hemorrhagic stroke. A genetic basis for AVMs is suspected, and we investigated potential mutations in a 14-year-old girl who developed a recurrent brain AVM. Whole-exome sequencing (WES) of AVM lesion tissue and blood was performed accompanied by in silico modeling, protein expression observation in lesion tissue and zebrafish modeling. A stop-gain mutation (c.C739T:p.R247X) in the gene SMAD family member 9 ( SMAD9 ) was discovered. In the human brain tissue, immunofluorescent staining demonstrated a vascular predominance of SMAD9 at the protein level. Vascular SMAD9 was markedly reduced in AVM peri-nidal blood vessels, which was accompanied by a decrease in phosphorylated SMAD4, a downstream effector protein of the bone morphogenic protein signaling pathway. Zebrafish modeling ( Tg kdrl:eGFP ) of the morpholino splice site and translation-blocking knockdown of SMAD9 resulted in abnormal cerebral artery-to-vein connections with morphologic similarities to human AVMs. Orthogonal trajectories of evidence established a relationship between the candidate mutation discovered in SMAD9 via WES and the clinical phenotype. Replication in similar rare cases of recurrent AVM, or even more broadly sporadic AVM, may be informative in building a more comprehensive understanding of AVM pathogenesis.

An overview on chemical derivatization and stability aspects of selected avermectin derivatives.

PubMed

Awasthi, Atul; Razzak, Majid; Al-Kassas, Raida; Harvey, Joanne; Garg, Sanjay

2012-01-01

Naturally occurring avermectins (AVMs) and its derivatives are potent endectocide compounds, well-known for their novel mode of action against a broad range of nematode and anthropod animal parasites. In this review, chemical and pharmaceutical aspects of AVM derivatives are described including stability, synthetic and purification processes, impurities and degradation pathways, and subsequent suggestions are made to improve the chemical stability. It has been found out that unique structure of AVM molecules and presence of labile groups facilitated the derivatization of AVM into various compounds showing strong anthelmintic activity. However, the same unique structure is also responsible for labile nature related to sensitive stability profile of molecules. AVMs are found to be unstable in acidic and alkaline conditions. In addition, these compounds are sensitive to strong light, and subsequently presence of photo-isomer in animals treated topically with AVM product is well known. The pharmacoepial recommendations for addition of antioxidant into drug substance, as well as its products, arises from the fact that AVM are very sensitive to oxidation. Formations of solvates, salts, epoxides, reduction of double bonds and developing liquid formulation around pH 6.2, were some chemical approaches used to retard the degradation in AVM. This coherent review will contribute towards the better understanding of the correlation of chemical processes, stability profile and biological activity; therefore, it will help to design the shelf-life stable formulations containing AVMs.

Intraosseous embolotherapy of central arteriovenous malformations in the jaw: long-term experience with 8 cases.

PubMed

Liu, Denggao; Ma, Xuchen; Zhao, Fuyun; Zhang, Jianguo

2009-11-01

To investigate the long-term effects of direct intraosseous histoacryl embolotherapy on central arteriovenous malformations (AVMs) of the jaw. Eight patients with central AVMs of the jaw (3 in the maxilla and 5 in the mandible) were treated with direct intraosseous histoacryl injection. These AVMs exhibited cystic radiolucency, with (n = 5) or without (n = 3) honeycombed component. On angiography, all the AVMs exhibited a large intraosseous nidus with multiple suppliers and drainages. The intraosseous lesions were percutaneously punctured with an 18- to 20-gauge needle, and NBCA diluted 30% to 40% with iodized oil was injected during venous compression. Postembolic arteriograms showed that all the AVMs were completely or nearly completely devascularized after single or multiple injections at the initial treatment. The follow-up period ranged from 3 to 8 years. Two AVMs experienced postembolic curettage and were anatomically cured. Three AVMs were anatomically cured after 1 to 3 sessions of embolotherapy. The other 3 AVMs were clinically cured after 1 (n = 2) to 4 (n = 1) sessions of embolotherapy. There were no procedure-related severe complications. Direct intraosseous glue embolotherapy can be a simple and safe technique for endovascular management of central AVMs in the jaw and is particularly effective in an emergency. Complete reossification of the intraosseous nidus can be anticipated if a complete occlusion is obtained.

Acoustic systems for the measurement of streamflow

USGS Publications Warehouse

Laenen, Antonius; Smith, Winchell

1982-01-01

Very little information is available concerning acoustic velocity meter (AVM) operation, performance, and limitations. This report provides a better understanding about the application of AVM instrumentation to streamflow measurment. Operational U.S. Geological Survey systems have proven that AVM equipment is accurate and dependable. AVM equipment has no practical upper limit of measureable velocity if sonic transducers are securely placed and adequately protected, and will measure velocitites as low as 0.1 meter per second which is normally less than the threshold level for mechanical or head-loss meters. In some situations the performance of AVM equipment may be degraded by multipath interference, signal bending, signal attenuation, and variable streamline orientation. Smaller, less-expensive, more conveniently operable microprocessor equipment is now available which should increase use of AVM systems in streamflow applications. (USGS)

International multicenter cohort study of pediatric brain arteriovenous malformations. Part 2: Outcomes after stereotactic radiosurgery.

PubMed

Starke, Robert M; Ding, Dale; Kano, Hideyuki; Mathieu, David; Huang, Paul P; Feliciano, Caleb; Rodriguez-Mercado, Rafael; Almodovar, Luis; Grills, Inga S; Silva, Danilo; Abbassy, Mahmoud; Missios, Symeon; Kondziolka, Douglas; Barnett, Gene H; Dade Lunsford, L; Sheehan, Jason P

2017-02-01

OBJECTIVE Pediatric patients (age < 18 years) harboring brain arteriovenous malformations (AVMs) are burdened with a considerably higher cumulative lifetime risk of hemorrhage than adults. Additionally, the pediatric population was excluded from recent prospective comparisons of intervention versus conservative management for unruptured AVMs. The aims of this multicenter, retrospective cohort study are to analyze the outcomes after stereotactic radiosurgery for unruptured and ruptured pediatric AVMs. METHODS We analyzed and pooled AVM radiosurgery data from 7 participating in the International Gamma Knife Research Foundation. Patients younger than 18 years of age who had at least 12 months of follow-up were included in the study cohort. Favorable outcome was defined as AVM obliteration, no post-radiosurgical hemorrhage, and no permanently symptomatic radiation-induced changes (RIC). The post-radiosurgery outcomes of unruptured versus ruptured pediatric AVMs were compared, and statistical analyses were performed to identify predictive factors. RESULTS The overall pediatric AVM cohort comprised 357 patients with a mean age of 12.6 years (range 2.8-17.9 years). AVMs were previously treated with embolization, resection, and fractionated external beam radiation therapy in 22%, 6%, and 13% of patients, respectively. The mean nidus volume was 3.5 cm 3 , 77% of AVMs were located in eloquent brain areas, and the Spetzler-Martin grade was III or higher in 59%. The mean radiosurgical margin dose was 21 Gy (range 5-35 Gy), and the mean follow-up was 92 months (range 12-266 months). AVM obliteration was achieved in 63%. During a cumulative latency period of 2748 years, the annual post-radiosurgery hemorrhage rate was 1.4%. Symptomatic and permanent radiation-induced changes occurred in 8% and 3%, respectively. Favorable outcome was achieved in 59%. In the multivariate logistic regression analysis, the absence of prior AVM embolization (p = 0.001) and higher margin dose (p < 0.001) were found to be independent predictors of a favorable outcome. The rates of favorable outcome for patients treated with a margin dose ≥ 22 Gy vs < 22 Gy were 78% (110/141 patients) and 47% (101/216 patients), respectively. A margin dose ≥ 22 Gy yielded a significantly higher probability of a favorable outcome (p < 0.001). The unruptured and ruptured pediatric AVM cohorts included 112 and 245 patients, respectively. Ruptured AVMs had significantly higher rates of obliteration (68% vs 53%, p = 0.005) and favorable outcome (63% vs 51%, p = 0.033), with a trend toward a higher incidence of post-radiosurgery hemorrhage (10% vs 4%, p = 0.07). The annual post-radiosurgery hemorrhage rates were 0.8% for unruptured and 1.6% for ruptured AVMs. CONCLUSIONS Radiosurgery is a reasonable treatment option for pediatric AVMs. Obliteration and favorable outcomes are achieved in the majority of patients. The annual rate of latency period hemorrhage after radiosurgery for both ruptured and unruptured pediatric AVM patients conveys a significant risk until the nidus is obliterated.

Delayed treatment of ruptured brain AVMs: is it ok to wait?

PubMed

Beecher, Jeffrey S; Lyon, Kristopher; Ban, Vin Shen; Vance, Awais; McDougall, Cameron M; Whitworth, Louis A; White, Jonathan A; Samson, Duke; Batjer, H Hunt; Welch, Babu G

2018-04-01

OBJECTIVE Despite a hemorrhagic presentation, many patients with arteriovenous malformations (AVMs) do not require emergency resection. The timing of definitive management is not standardized in the cerebrovascular community. This study was designed to evaluate the safety of delaying AVM treatment in clinically stable patients with a new hemorrhagic presentation. The authors examined the rate of rehemorrhage or neurological decline in a cohort of patients with ruptured brain AVMs during a period of time posthemorrhage. METHODS Patients presenting to the authors' institution from January 2000 to December 2015 with ruptured brain AVMs treated at least 4 weeks posthemorrhage were included in this analysis. Exclusion criteria were ruptured AVMs that required emergency surgery involving resection of the AVM, prior treatment of AVM at another institution, or treatment of lesions within 4 weeks for other reasons (subacute surgery). The primary outcome measure was time from initial hemorrhage to treatment failure (defined as rehemorrhage or neurological decline as a direct result of the AVM). Patient-days were calculated from the day of initial rupture until the day AVM treatment was initiated or treatment failed. RESULTS Of 102 ruptured AVMs in 102 patients meeting inclusion criteria, 7 (6.9%) failed the treatment paradigm. Six patients (5.8%) had a new hemorrhage within a median of 248 days (interquartile range 33-1364 days). The total "at risk" period was 18,740 patient-days, yielding a rehemorrhage rate of 11.5% per patient-year, or 0.96% per patient-month. Twelve (11.8%) of 102 patients were found to have an associated aneurysm. In this group there was a single (8.3%) new hemorrhage during a total at-risk period of 263 patient-days until the aneurysm was secured, yielding a rehemorrhage risk of 11.4% per patient-month. CONCLUSIONS It is the authors' practice to rehabilitate patients after brain AVM rupture with a plan for elective treatment of the AVM. The present data are useful in that the findings quantify the risk of the authors' treatment strategy. These findings indicate that delaying intervention for at least 4 weeks after the initial hemorrhage subjects the patient to a low (< 1%) risk of rehemorrhage. The authors modified the treatment paradigm when a high-risk feature, such as an associated intracranial aneurysm, was identified.

Developmental deficits in adult patients with arteriovenous malformations.

PubMed

Lazar, R M; Connaire, K; Marshall, R S; Pile-Spellman, J; Hacein-Bey, L; Solomon, R A; Sisti, M B; Young, W L; Mohr, J P

1999-01-01

Cerebral arteriovenous malformations (AVMs) are congenital masses of arteries and veins that appear to undergo an unclear "maturation" for many years. Using structured interviews, we compared developmental history of adult patients with AVM with a comparison group of patients with cerebral tumor or aneurysm. To determine whether a remote history of developmental abnormality in adult patients with AVM might be an early marker of cerebral status. Adult patients with AVM and a comparison group of patients with cerebral aneurysm or low-grade tumor participated in a survey. Urban medical school-based tertiary care center. Forty-four randomly selected patients with AVM from the Columbia-Presbyterian AVM Database. There were 32 comparison patients:15 randomly chosen patients from the institution's Cerebral Aneurysm Database and all 17 patients who underwent a biopsy from 1990 to 1995 with a diagnosis of low-grade tumor and who could be contacted. A brief, structured interview adapted from the Centers for Disease Control and Prevention for its 1994 study of the prevalence of learning disabilities in American children. We defined the positive occurrence of a condition as an affirmative answer to the question, " Did have (condition) during his/her school-age years?" Each patient was also asked if there had been any problems in the following skill areas: reading, writing, listening, speaking, attention, impulsivity, organization, mathematics, or drawing. The AVM size was calculated on the angiographic film by measuring its longest diameter in any dimension. Patients with AVM were significantly more likely to report a positive occurrence to any survey question (P<.05). Two thirds of all patients with AVM (66%) reported at least 1 skill difficulty during their school years, significantly more than the comparison group (P<.001). Neither the maximum AVM diameter nor the occurrence of hemorrhage as an adult differed between patients with AVM with and without early skill difficulty. Patients with AVM are more likely to report a developmental learning disorder than patients with tumor or aneurysm despite the absence of other neurologic symptoms of diseases not diagnosed for another 20 years. These data support the notion that disorders of behavioral and intellectual function are sensitive markers of early cerebral status.

Injections of Intravenous Contrast for Computerized Tomography Scans Precipitate Migraines in Hereditary Hemorrhagic Telangiectasia Subjects at Risk of Paradoxical Emboli: Implications for Right-to-Left Shunt Risks.

PubMed

Patel, Trishan; Elphick, Amy; Jackson, James E; Shovlin, Claire L

2016-11-01

To evaluate if injection of intravenous particles may provoke migraines in subjects with right-to-left shunts due to pulmonary arteriovenous malformations (AVMs). Migraine headaches commonly affect people with hereditary hemorrhagic telangiectasia (HHT), especially those with pulmonary AVMs that provide right-to-left shunts. In our clinical practice, patients occasionally reported acute precipitation of migraine headaches following injection of technetium-labeled albumin macroaggregates for nuclear medicine scans. Self-reported migraine features and exacerbations were examined in HHT subjects with and without pulmonary AVMs, for a series of noninvasive and invasive investigations, using an unbiased online survey. One hundred and sixty-six subjects were classified as having both HHT and migraines. HHT subjects with migraines were more likely to have pulmonary AVMs (P < .0001). HHT subjects with pulmonary AVMs were more likely to report photophobia (P = .010), "flashes of light" (P = .011), or transient visual loss (P = .040). Pulse oximetry, x-rays, ultrasound, and computerized tomography (CT) scans without intravenous contrast medium rarely, if ever, provoked migraines, but unenhanced magnetic resonance imaging (MRI) was reported to exacerbate migraines by 14/124 (11.2%) subjects. One hundred and fourteen subjects had both enhanced and unenhanced CT examinations: studies with contrast media were more commonly reported to start (9/114 [7.8%]), and/or worsen migraines (18/114 [15.7%]), compared to those undertaken without contrast medium (P < .01), or after simple blood tests (P < .05). Additionally, migraine exacerbation was reported by 9/90 (10%) after contrast echocardiography, 2/44 (4.5%) after nuclear medicine scans, and 10/154 (6.5%) after blood tests. HHT subjects frequently report migraine exacerbation following blood tests, contrast echocardiograms, MRI imaging, and CT studies performed with intravenous contrast medium. Since air emboli are recognized to complicate intravenous injections, particularly those given by a pressurized pump during contrast enhanced CT, future studies should re-evaluate whether particulate emboli provoke migraines. © 2016 The Authors Headache published by Wiley Periodicals, Inc. on behalf of American Headache Society.

Injections of Intravenous Contrast for Computerized Tomography Scans Precipitate Migraines in Hereditary Hemorrhagic Telangiectasia Subjects at Risk of Paradoxical Emboli: Implications for Right‐to‐Left Shunt Risks

PubMed Central

Patel, Trishan; Elphick, Amy; Jackson, James E.

2016-01-01

Objective To evaluate if injection of intravenous particles may provoke migraines in subjects with right‐to‐left shunts due to pulmonary arteriovenous malformations (AVMs). Background Migraine headaches commonly affect people with hereditary hemorrhagic telangiectasia (HHT), especially those with pulmonary AVMs that provide right‐to‐left shunts. In our clinical practice, patients occasionally reported acute precipitation of migraine headaches following injection of technetium‐labeled albumin macroaggregates for nuclear medicine scans. Methods Self‐reported migraine features and exacerbations were examined in HHT subjects with and without pulmonary AVMs, for a series of noninvasive and invasive investigations, using an unbiased online survey. Results One hundred and sixty‐six subjects were classified as having both HHT and migraines. HHT subjects with migraines were more likely to have pulmonary AVMs (P < .0001). HHT subjects with pulmonary AVMs were more likely to report photophobia (P = .010), “flashes of light” (P = .011), or transient visual loss (P = .040). Pulse oximetry, x‐rays, ultrasound, and computerized tomography (CT) scans without intravenous contrast medium rarely, if ever, provoked migraines, but unenhanced magnetic resonance imaging (MRI) was reported to exacerbate migraines by 14/124 (11.2%) subjects. One hundred and fourteen subjects had both enhanced and unenhanced CT examinations: studies with contrast media were more commonly reported to start (9/114 [7.8%]), and/or worsen migraines (18/114 [15.7%]), compared to those undertaken without contrast medium (P < .01), or after simple blood tests (P < .05). Additionally, migraine exacerbation was reported by 9/90 (10%) after contrast echocardiography, 2/44 (4.5%) after nuclear medicine scans, and 10/154 (6.5%) after blood tests. Conclusions HHT subjects frequently report migraine exacerbation following blood tests, contrast echocardiograms, MRI imaging, and CT studies performed with intravenous contrast medium. Since air emboli are recognized to complicate intravenous injections, particularly those given by a pressurized pump during contrast enhanced CT, future studies should re‐evaluate whether particulate emboli provoke migraines. PMID:27727478

Acute fatal hemorrhage from previously undiagnosed cerebral arteriovenous malformations in children: a single-center experience.

PubMed

Riordan, Coleman P; Orbach, Darren B; Smith, Edward R; Scott, R Michael

2018-06-01

OBJECTIVE The most significant adverse outcome of intracranial hemorrhage from an arteriovenous malformation (AVM) is death. This study reviews a single-center experience with pediatric AVMs to quantify the incidence and characterize clinical and radiographic factors associated with sudden death from the hemorrhage of previously undiagnosed AVMs in children. METHODS A single-center database review of the period from 2006 to 2017 identified all patients with a first-time intracranial hemorrhage from a previously undiagnosed AVM. Clinical and radiographic data were collected and compared between patients who survived to hospital discharge and those who died at presentation. RESULTS A total of 57 patients (average age 10.8 years, range 0.1-19 years) presented with first-time intracranial hemorrhage from a previously undiagnosed AVM during the study period. Of this group, 7/57 (12%) patients (average age 11.5 years, range 6-16 years) suffered hemorrhages that led directly to their deaths. Compared to the cohort of patients who survived their hemorrhage, patients who died were 4 times more likely to have an AVM in the posterior fossa. No clear pattern of antecedent triggering activity (sports, trauma, etc.) was identified, and 3/7 (43%) experienced cardiac arrest in the prehospital setting. Surviving patients were ultimately treated with resection of the AVM in 42/50 (84%) of cases. CONCLUSIONS Children who present with hemorrhage from a previously undiagnosed intracranial AVM had a 12% chance of sudden death in our single-institution series of pediatric cerebrovascular cases. Clinical triggers of hemorrhage are unpredictable, but subsequent radiographic evidence of a posterior fossa AVM was present in 57% of fatal cases, and all fatal cases were in locations with high risk of potential herniation. These data support a proactive, aggressive approach toward definitive treatment of AVMs in children.

Prediction of obliteration after gamma knife surgery for cerebral arteriovenous malformations.

PubMed

Karlsson, B; Lindquist, C; Steiner, L

1997-03-01

To define the factors of importance for the obliteration of cerebral arteriovenous malformations (AVMs), thus making a prediction of the probability for obliteration possible. In 945 AVMs of a series of 1319 patients treated with the gamma knife during 1970 to 1990, the relationship between patient, AVMs, and treatment parameters on the one hand and the obliteration of the nidus on the other was analyzed. The obliteration rate increased both with increased minimum (lowest periphery) and average dose and decreased with increased AVM volume. The minimum dose to the AVMs was the decisive dose factor for the treatment result. The higher the minimum dose, the higher the chance for total obliteration. The curve illustrating this relation increased logarithmically to a value of 87%. A higher average dose shortened the latency to AVM obliteration. For the obliterated cases, the larger the malformation, the lower the minimum dose used. This prompted us to relate the obliteration rate to the product minimum dose (AVM volume)1/3 (K index). The obliteration rate increased linearly with the K index up to a value of approximately 27, and for higher K values, the obliteration rate had a constant value of approximately 80%. For the group of 273 cases treated with a minimum dose of at least 25 Gy, the obliteration rate at the study end point (defined as 2-yr latency) was 80% (95% confidence interval = 75-85%). If obliterations that occurred beyond the end point are included, the obliteration rate increased to 85% (81-89%). The probability of obliteration of AVMs after gamma knife surgery is related both to the lowest dose to the AVMs and the AVM volume, and it can be predicted using the K index.

Balloon-Occluded Retrograde Transvenous Obliteration of a Gastric Vascular Malformation: An Innovative Approach to Treatment of a Rare Condition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansing, Catherine E., E-mail: catherine.e.hansing.mil@mail.mil; Marquardt, Joseph P.; Sutton, Daniel M.

Arteriovenous malformations (AVMs) are a high-flow form of a vascular malformation, which can be found anywhere in the body. While historically treated surgically, a multidisciplinary approach utilizing multiple specialties and treatment modalities is now commonly employed. In order to effectively treat an AVM, the nidus must be targeted and eradicated, which can be done via multiple approaches. We present the case of a 43-year-old male with a gastric wall AVM, which was initially incompletely treated using a percutaneous transarterial approach. The gastric AVM was noted to have dominant drainage through a gastrorenal shunt; therefore, Balloon-occluded Retrograde Transvenous Obliteration (BRTO) wasmore » utilized to eradicate the AVM nidus. This case illustrates the utility of Interventional Radiology, specifically BRTO, as another treatment option for challenging AVMs.« less

Complications Following Linear Accelerator Based Stereotactic Radiation for Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skjoth-Rasmussen, Jane, E-mail: jane@skjoeth-rasmussen.d; Roed, Henrik; Ohlhues, Lars

2010-06-01

Purpose: Primarily, gamma knife centers are predominant in publishing results on arteriovenous malformations (AVM) treatments including reports on risk profile. However, many patients are treated using a linear accelerator-most of these at smaller centers. Because this setting is different from a large gamma knife center, the risk profile at Linac departments could be different from the reported experience. Prescribed radiation doses are dependent on AVM volume. This study details results from a medium sized Linac department center focusing on risk profiles. Method and Materials: A database was searched for all patients with AVMs. We included 50 consecutive patients with amore » minimum of 24 months follow-up (24-51 months). Results: AVM occlusion was verified in 78% of patients (39/50). AVM occlusion without new deficits (excellent outcome) was obtained in 44%. Good or fair outcome (AVM occlusion with mild or moderate new deficits) was seen in 30%. Severe complications after AVM occlusion occurred in 4% with a median interval of 15 months after treatment (range, 1-26 months). Conclusions: We applied an AVM grading score developed at the Mayo Clinic to predict probable outcome after radiosurgery in a large patient population treated with Gamma knife. A cutoff above and below a score of 1.5 could not discriminate between the likelihood of having an excellent outcome (approximately 45%). The chance of having an excellent or good outcome was slightly higher in patients with an AVM score below 1.5 (64% vs. 57%).« less

Complications following linear accelerator based stereotactic radiation for cerebral arteriovenous malformations.

PubMed

Skjøth-Rasmussen, Jane; Roed, Henrik; Ohlhues, Lars; Jespersen, Bo; Juhler, Marianne

2010-06-01

Primarily, gamma knife centers are predominant in publishing results on arteriovenous malformations (AVM) treatments including reports on risk profile. However, many patients are treated using a linear accelerator-most of these at smaller centers. Because this setting is different from a large gamma knife center, the risk profile at Linac departments could be different from the reported experience. Prescribed radiation doses are dependent on AVM volume. This study details results from a medium sized Linac department center focusing on risk profiles. A database was searched for all patients with AVMs. We included 50 consecutive patients with a minimum of 24 months follow-up (24-51 months). AVM occlusion was verified in 78% of patients (39/50). AVM occlusion without new deficits (excellent outcome) was obtained in 44%. Good or fair outcome (AVM occlusion with mild or moderate new deficits) was seen in 30%. Severe complications after AVM occlusion occurred in 4% with a median interval of 15 months after treatment (range, 1-26 months). We applied an AVM grading score developed at the Mayo Clinic to predict probable outcome after radiosurgery in a large patient population treated with Gamma knife. A cutoff above and below a score of 1.5 could not discriminate between the likelihood of having an excellent outcome (approximately 45%). The chance of having an excellent or good outcome was slightly higher in patients with an AVM score below 1.5 (64% vs. 57%). Copyright 2010 Elsevier Inc. All rights reserved.

Overall outcomes following early interventions for intracranial arteriovenous malformations with hematomas.

PubMed

Bir, Shyamal C; Maiti, Tanmoy Kumar; Konar, Subhas; Nanda, Anil

2016-01-01

We evaluated the timing and predictors of surgical intervention for intracranial arteriovenous malformations (AVM) with hematoma. A ruptured intracranial AVM with hematoma is an emergency condition, and the optimal timing for surgical intervention is not well understood. In addition, the outcome predictors of surgical intervention have rarely been reported. We identified and analyzed 78 patients treated with microsurgical resection for pathologically proven AVM at Louisiana State University Health in Shreveport from February 1992 to December 2004. All 78 patients were diagnosed with ruptured AVM before surgery. The independent variables, including patient demographics, timing of surgery, location of the AVM and comorbidities were analyzed to assess outcome. The results of this series revealed that surgical intervention after 48hours resulted in poor outcomes for patients with hematoma, following a ruptured AVM. Several other prognostic factors, including younger age (11-40years), Spetzler-Martin Grade I and II, and AVM in a supratentorial location, had significant positive effects on outcomes. However, hypertension, smoking, and a prior embolization showed significant negative effects on outcomes after surgery. The multiple logistic regression analyses also revealed that the timing of surgical intervention had a significant effect on outcomes in patients with hematoma following ruptured AVM. Early intervention is the key to success in these patients. Published by Elsevier Ltd.

The Value of Data and Metadata Standardization for Interoperability in Giovanni

NASA Astrophysics Data System (ADS)

Smit, C.; Hegde, M.; Strub, R. F.; Bryant, K.; Li, A.; Petrenko, M.

2017-12-01

Giovanni (https://giovanni.gsfc.nasa.gov/giovanni/) is a data exploration and visualization tool at the NASA Goddard Earth Sciences Data Information Services Center (GES DISC). It has been around in one form or another for more than 15 years. Giovanni calculates simple statistics and produces 22 different visualizations for more than 1600 geophysical parameters from more than 90 satellite and model products. Giovanni relies on external data format standards to ensure interoperability, including the NetCDF CF Metadata Conventions. Unfortunately, these standards were insufficient to make Giovanni's internal data representation truly simple to use. Finding and working with dimensions can be convoluted with the CF Conventions. Furthermore, the CF Conventions are silent on machine-friendly descriptive metadata such as the parameter's source product and product version. In order to simplify analyzing disparate earth science data parameters in a unified way, we developed Giovanni's internal standard. First, the format standardizes parameter dimensions and variables so they can be easily found. Second, the format adds all the machine-friendly metadata Giovanni needs to present our parameters to users in a consistent and clear manner. At a glance, users can grasp all the pertinent information about parameters both during parameter selection and after visualization. This poster gives examples of how our metadata and data standards, both external and internal, have both simplified our code base and improved our users' experiences.

High-Flow Arteriovenous Malformation of the Lower Extremity: Ethanolamine Oleate Sclerotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyodoh, Hideki; Fujita, Akifumi; Hyodoh, Kazusa

2001-09-15

We report the case of a young man presenting with high-flow arteriovenous malformation (AVM), in whom percutaneous direct nidus puncture ethanolamine oleate (EO) sclerotherapy was useful in the management of the AVM. To our knowledge, this is the first report of percutaneous trans-nidus EO sclerotherapy for AVM in the extremities. Percutaneous trans-nidus sclerotherapy should be considered as an alternative choice for the management of symptomatic AVM.

Formal proof of the AVM-1 microprocessor using the concept of generic interpreters

NASA Technical Reports Server (NTRS)

Windley, P.; Levitt, K.; Cohen, G. C.

1991-01-01

A microprocessor designated AVM-1 was designed to demonstrate the use of generic interpreters in verifying hierarchically decomposed microprocessor specifications. This report is intended to document the high-order language (HOL) code verifying AVM-1. The organization of the proof is discussed and some technical details concerning the execution of the proof scripts in HOL are presented. The proof scripts used to verify AVM-1 are also presented.

Radiosurgery for cerebral arteriovenous malformations in hereditary hemorrhagic telangiectasia.

PubMed

Maarouf, M; Runge, M; Kocher, M; Zähringer, M; Treuer, H; Sturm, V

2004-07-27

The authors evaluated the efficacy of radiosurgery (RS) for cerebral arteriovenous malformations in hereditary hemorrhagic telangiectasia (HHT AVMs). Two patients with seven HHT AVMs were treated by linear accelerator-RS. Complete obliteration was achieved 18 to 24 months post-treatment without side effects. Because HHT AVMs are small and multiple, RS is superior to microsurgery because it is noninvasive and all AVMs can be treated in one session regardless of their location.

Acoustic systems for the measurement of streamflow

USGS Publications Warehouse

Laenen, Antonius; Smith, Winchell

1983-01-01

The acoustic velocity meter (AVM), also referred to as an ultrasonic flowmeter, has been an operational tool for the measurement of streamflow since 1965. Very little information is available concerning AVM operation, performance, and limitations. The purpose of this report is to consolidate information in such a manner as to provide a better understanding about the application of this instrumentation to streamflow measurement. AVM instrumentation is highly accurate and nonmechanical. Most commercial AVM systems that measure streamflow use the time-of-travel method to determine a velocity between two points. The systems operate on the principle that point-to-point upstream travel-time of sound is longer than the downstream travel-time, and this difference can be monitored and measured accurately by electronics. AVM equipment has no practical upper limit of measurable velocity if sonic transducers are securely placed and adequately protected. AVM systems used in streamflow measurement generally operate with a resolution of ?0.01 meter per second but this is dependent on system frequency, path length, and signal attenuation. In some applications the performance of AVM equipment may be degraded by multipath interference, signal bending, signal attenuation, and variable streamline orientation. Presently used minicomputer systems, although expensive to purchase and maintain, perform well. Increased use of AVM systems probably will be realized as smaller, less expensive, and more conveniently operable microprocessor-based systems become readily available. Available AVM equipment should be capable of flow measurement in a wide variety of situations heretofore untried. New signal-detection techniques and communication linkages can provide additional flexibility to the systems so that operation is possible in more river and estuary situations.

Non-Enhanced MR Imaging of Cerebral Arteriovenous Malformations at 7 Tesla.

PubMed

Wrede, Karsten H; Dammann, Philipp; Johst, Sören; Mönninghoff, Christoph; Schlamann, Marc; Maderwald, Stefan; Sandalcioglu, I Erol; Ladd, Mark E; Forsting, Michael; Sure, Ulrich; Umutlu, Lale

2016-03-01

To evaluate prospectively 7 Tesla time-of-flight (TOF) magnetic resonance angiography (MRA) and 7 Tesla non-contrast-enhanced magnetization-prepared rapid acquisition gradient-echo (MPRAGE) for delineation of intracerebral arteriovenous malformations (AVMs) in comparison to 1.5 Tesla TOF MRA and digital subtraction angiography (DSA). Twenty patients with single or multifocal AVMs were enrolled in this trial. The study protocol comprised 1.5 and 7 Tesla TOF MRA and 7 Tesla non-contrast-enhanced MPRAGE sequences. All patients underwent an additional four-vessel 3D DSA. Image analysis of the following five AVM features was performed individually by two radiologists on a five-point scale: nidus, feeder(s), draining vein(s), relationship to adjacent vessels, and overall image quality and presence of artefacts. A total of 21 intracerebral AVMs were detected. Both sequences at 7 Tesla were rated superior over 1.5 Tesla TOF MRA in the assessment of all considered AVM features. Image quality at 7 Tesla was comparable with DSA considering both sequences. Inter-observer accordance was good to excellent for the majority of ratings. This study demonstrates excellent image quality for depiction of intracerebral AVMs using non-contrast-enhanced 7 Tesla MRA, comparable with DSA. Assessment of untreated AVMs is a promising clinical application of ultra-high-field MRA. • Non-contrast-enhanced 7 Tesla MRA demonstrates excellent image quality for intracerebral AVM depiction. • Image quality at 7 Tesla was comparable with DSA considering both sequences. • Assessment of intracerebral AVMs is a promising clinical application of ultra-high-field MRA.

Intraoperative monitoring of brain tissue oxygenation during arteriovenous malformation resection.

PubMed

Arikan, Fuat; Vilalta, Jordi; Noguer, Montserrat; Olive, Montserrat; Vidal-Jorge, Marian; Sahuquillo, Juan

2014-10-01

In normal perfusion pressure breakthrough (NPPB) it is assumed that following arteriovenous malformation (AVM) resection, vasoparalysis persists in the margins of the lesion and that a sudden increase in cerebral blood flow (CBF) after AVM exclusion leads to brain swelling and postsurgical complications. However, the pathophysiology NPPB remains controversial.The aim of our study was to investigate the oxygenation status in tissue surrounding AVMs and in the distant brain using intraoperative monitoring of cerebral partial pressure of oxygen (PtiO(2)) to achieve a better understanding of NPPB pathophysiology. Patients with supratentorial AVMs were monitored intraoperatively using 2 polarographic Clark-type electrodes. To establish reference values, we also studied PtiO(2) in a group of patients who underwent surgery to treat incidental aneurysms. Twenty-two patients with supratentorial AVMs and 16 patients with incidentally found aneurysms were included. Hypoxic pattern was defined as PtiO(2)≤15 mm Hg and/or PtiO(2)/PaO(2) ratio ≤0.10. Tissue hypoxia was detected in 63.6% of the catheters placed in the perinidal area and in 43.8% of catheters placed in a distant area. AVM excision significantly improved oxygenation both around the AVM and in the distant area. The PtiO(2)/PaO(2) ratio is a better indicator than absolute PtiO(2) in detecting tissue hypoxia in mechanically ventilated patients. Intraoperative monitoring showed tissue hypoxia in the margins of AVMs and in the distant ipsilateral brain as the most common finding. Surgical removal of AVMs induces a significant improvement in the oxygenation status in both areas.

Three-dimensional brain arteriovenous malformation models for clinical use and resident training.

PubMed

Dong, Mengqi; Chen, Guangzhong; Li, Jianyi; Qin, Kun; Ding, Xiaowen; Peng, Chao; Zhou, Dong; Lin, Xiaofeng

2018-01-01

To fabricate three-dimensional (3D) models of brain arteriovenous malformation (bAVM) and report our experience with customized 3D printed models of patients with bAVM as an educational and clinical tool for patients, doctors, and surgical residents. Using computerized tomography angiography (CTA) or digital subtraction angiography (DSA) images, the rapid prototyping process was completed with specialized software and "in-house" 3D printing service. Intraoperative validation of model fidelity was performed by comparing to DSA images of the same patient during the endovascular treatment process. 3D bAVM models were used for preoperative patient education and consultation, surgical planning, and resident training. 3D printed bAVM models were successful made. By neurosurgeons' evaluation, the printed models precisely replicated the actual bAVM structure of the same patients (n = 7, 97% concordance, range 95%-99% with average of < 2 mm variation). The use of 3D models was associated shorter time for preoperative patient education and consultation, higher acceptable of the procedure for patients and relatives, shorter time between obtaining intraoperative DSA data and the start of endovascular treatment. Thirty surgical residents from residency programs tested the bAVM models and provided feedback on their resemblance to real bAVM structures and the usefulness of printed solid model as an educational tool. Patient-specific 3D printed models of bAVM can be constructed with high fidelity. 3D printed bAVM models were proven to be helpful in preoperative patient consultation, surgical planning, and resident training. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Bipolar electrocoagulation on cortex after AVMs lesionectomy for seizure control.

PubMed

Cao, Yong; Wang, Rong; Yang, Lijun; Bai, Qin; Wang, Shuo; Zhao, Jizong

2011-01-01

The findings of previous studies remain controversial on the optimal management required for effective seizure control after surgical excision of arteriovenous malformations (AVMs). We evaluated the efficacy of additional bipolar electrocoagulation on the electrically positive cortex guided by intraoperative electrocorticography (ECoG) for controlling cerebral AVMs-related epilepsy. Sixty consecutive patients with seizure due to cerebral AVMs, who underwent surgical excision of cerebral AVMs and intraoperative ECoG, were assessed. The AVMs and surrounding hemosiderin stained tissue were completely removed, and bipolar electrocoagulation was applied on the surrounding cerebral cortex where epileptic discharges were monitored via intraoperative ECoG. Patients were followed up at three to six months after the surgery and then annually. We evaluated seizure outcome by using Engel's classification and postoperative complications. Forty-nine patients (81.6%) were detected of epileptic discharges before and after AVMs excision. These patients underwent the removal of AVMs plus bipolar electrocoagulation on spike-positive site cortex. After electrocoagulation, 45 patients' epileptic discharges disappeared, while four obviously diminished. Fifty-five of 60 patients (91.7%) had follow-up lasting at least 22 months (mean 51.1 months; range 22-93 months). Determined by the Engel Seizure Outcome Scale, 39 patients (70.9%) were Class I, seven (12.7%) Class II, five (9.0%) Class III, and four (7.2%) Class IV. Even after the complete removal of AVM and surrounding gliotic and hemosiderin stained tissue, a high-frequency residual spike remained on the surrounding cerebral cortex. Effective surgical seizure control can be achieved by carrying out additional bipolar electrocoagulation on the cortex guided by the intraoperative ECoG.

Socioeconomic Impact Assessment of the Los Angeles Automatic Vehicle Monitoring (AVM) Demonstration

DOT National Transportation Integrated Search

1982-09-01

This report presents a socioeconomic impact assessment of the Automatic Vehicle Monitoring (AVM) Demonstration in Los Angeles. An AVM system uses location, communication, and data processing subsystems to monitor the locations of appropriately equipp...

Attempts to identify the source of avian vacuolar myelinopathy for waterbirds

USGS Publications Warehouse

Rocke, T.E.; Thomas, N.J.; Meteyer, C.U.; Quist, C.F.; Fischer, John R.; Augspurger, T.; Ward, S.E.

2005-01-01

Attempts were made to reproduce avian vacuolar myelinopathy (AVM) in a number of test animals in order to determine the source of the causative agent for birds and to find a suitable animal model for future studies. Submerged vegetation, plankton, invertebrates, forage fish, and sediments were collected from three lakes with ongoing outbreaks of AVM and fed to American coots (Fulica americana), mallard ducks and ducklings (Anas platyrhynchos), quail (Coturnix japonica), and laboratory mice either via gavage or ad libitum. Tissues from AVM-affected coots with brain lesions were fed to ducklings, kestrels (Falco sparverius), and American crows (Corvus brachyrhynchos). Two mallards that ingested one sample of Hydrilla verticillata along with any biotic or abiotic material associated with its external surface developed brain lesions consistent with AVM, although neither of the ducks had clinical signs of disease. Ingestion of numerous other samples of Hydrilla from the AVM affected lakes and a lake with no prior history of AVM, other materials (sediments, algae, fish, invertebrates, and water from affected lakes), or tissues from AVM-affected birds did not produce either clinical signs or brain lesions in any of the other test animals in our studies. These results suggest that waterbirds are most likely exposed to the causative agent of AVM while feeding on aquatic vegetation, but we do not believe the vegetation itself is the agent. We hypothesize that the causative agent of AVM might either be accumulated by aquatic vegetation, such as Hydrilla, or associated with biotic or abiotic material on its external surfaces. In support of that hypothesis, two coots that ingested Hydrilla sampled from a lake with an ongoing AVM outbreak in wild birds developed neurologic signs within 9 days (ataxia, limb weakness, and incoordination), and one of two coots that ingested Hydrilla collected from the same site 13 days later became sick and died within 38 days. None of these three sick coots had definitive brain lesions consistent with AVM by light microscopy, but they had no gross or histologic lesions in other tissues. It is unclear if these birds died of AVM. Perhaps they did not ingest a dose sufficient to produce brain lesions or the lesions were ultrastructural. Alternatively, it is possible that a separate neurotoxic agent is responsible for the morbidity and mortality observed in these coots.

The Climate-G testbed: towards a large scale data sharing environment for climate change

NASA Astrophysics Data System (ADS)

Aloisio, G.; Fiore, S.; Denvil, S.; Petitdidier, M.; Fox, P.; Schwichtenberg, H.; Blower, J.; Barbera, R.

2009-04-01

The Climate-G testbed provides an experimental large scale data environment for climate change addressing challenging data and metadata management issues. The main scope of Climate-G is to allow scientists to carry out geographical and cross-institutional climate data discovery, access, visualization and sharing. Climate-G is a multidisciplinary collaboration involving both climate and computer scientists and it currently involves several partners such as: Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Institut Pierre-Simon Laplace (IPSL), Fraunhofer Institut für Algorithmen und Wissenschaftliches Rechnen (SCAI), National Center for Atmospheric Research (NCAR), University of Reading, University of Catania and University of Salento. To perform distributed metadata search and discovery, we adopted a CMCC metadata solution (which provides a high level of scalability, transparency, fault tolerance and autonomy) leveraging both on P2P and grid technologies (GRelC Data Access and Integration Service). Moreover, data are available through OPeNDAP/THREDDS services, Live Access Server as well as the OGC compliant Web Map Service and they can be downloaded, visualized, accessed into the proposed environment through the Climate-G Data Distribution Centre (DDC), the web gateway to the Climate-G digital library. The DDC is a data-grid portal allowing users to easily, securely and transparently perform search/discovery, metadata management, data access, data visualization, etc. Godiva2 (integrated into the DDC) displays 2D maps (and animations) and also exports maps for display on the Google Earth virtual globe. Presently, Climate-G publishes (through the DDC) about 2TB of data related to the ENSEMBLES project (also including distributed replicas of data) as well as to the IPCC AR4. The main results of the proposed work are: wide data access/sharing environment for climate change; P2P/grid metadata approach; production-level Climate-G DDC; high quality tools for data visualization; metadata search/discovery across several countries/institutions; open environment for climate change data sharing.

Pathophysiology of increased cerebrospinal fluid pressure associated to brain arteriovenous malformations: The hydraulic hypothesis.

PubMed

Rossitti, Sandro

2013-01-01

Brain arteriovenous malformations (AVMs) produce circulatory and functional disturbances in adjacent as well as in remote areas of the brain, but their physiological effect on the cerebrospinal fluid (CSF) pressure is not well known. The hypothesis of an intrinsic disease mechanism leading to increased CSF pressure in all patients with brain AVM is outlined, based on a theory of hemodynamic control of intracranial pressure that asserts that CSF pressure is a fraction of the systemic arterial pressure as predicted by a two-resistor series circuit hydraulic model. The resistors are the arteriolar resistance (that is regulated by vasomotor tonus), and the venous resistance (which is mechanically passive as a Starling resistor). This theory is discussed and compared with the knowledge accumulated by now on intravasal pressures and CSF pressure measured in patients with brain AVM. The theory provides a basis for understanding the occurrence of pseudotumor cerebri syndrome in patients with nonhemorrhagic brain AVMs, for the occurrence of local mass effect and brain edema bordering unruptured AVMs, and for the development of hydrocephalus in patients with unruptured AVMs. The theory also contributes to a better appreciation of the pathophysiology of dural arteriovenous fistulas, of vein of Galen aneurismal malformation, and of autoregulation-related disorders in AVM patients. The hydraulic hypothesis provides a comprehensive frame to understand brain AVM hemodynamics and its effect on the CSF dynamics.

Pathophysiology of increased cerebrospinal fluid pressure associated to brain arteriovenous malformations: The hydraulic hypothesis

PubMed Central

Rossitti, Sandro

2013-01-01

Background: Brain arteriovenous malformations (AVMs) produce circulatory and functional disturbances in adjacent as well as in remote areas of the brain, but their physiological effect on the cerebrospinal fluid (CSF) pressure is not well known. Methods: The hypothesis of an intrinsic disease mechanism leading to increased CSF pressure in all patients with brain AVM is outlined, based on a theory of hemodynamic control of intracranial pressure that asserts that CSF pressure is a fraction of the systemic arterial pressure as predicted by a two-resistor series circuit hydraulic model. The resistors are the arteriolar resistance (that is regulated by vasomotor tonus), and the venous resistance (which is mechanically passive as a Starling resistor). This theory is discussed and compared with the knowledge accumulated by now on intravasal pressures and CSF pressure measured in patients with brain AVM. Results: The theory provides a basis for understanding the occurrence of pseudotumor cerebri syndrome in patients with nonhemorrhagic brain AVMs, for the occurrence of local mass effect and brain edema bordering unruptured AVMs, and for the development of hydrocephalus in patients with unruptured AVMs. The theory also contributes to a better appreciation of the pathophysiology of dural arteriovenous fistulas, of vein of Galen aneurismal malformation, and of autoregulation-related disorders in AVM patients. Conclusions: The hydraulic hypothesis provides a comprehensive frame to understand brain AVM hemodynamics and its effect on the CSF dynamics. PMID:23607064

Real-time imaging of de novo arteriovenous malformation in a mouse model of hereditary hemorrhagic telangiectasia

PubMed Central

Park, Sung Ok; Wankhede, Mamta; Lee, Young Jae; Choi, Eun-Jung; Fliess, Naime; Choe, Se-Woon; Oh, Seh-Hoon; Walter, Glenn; Raizada, Mohan K.; Sorg, Brian S.; Oh, S. Paul

2009-01-01

Arteriovenous malformations (AVMs) are vascular anomalies where arteries and veins are directly connected through a complex, tangled web of abnormal arteries and veins instead of a normal capillary network. AVMs in the brain, lung, and visceral organs, including the liver and gastrointestinal tract, result in considerable morbidity and mortality. AVMs are the underlying cause of three major clinical symptoms of a genetic vascular dysplasia termed hereditary hemorrhagic telangiectasia (HHT), which is characterized by recurrent nosebleeds, mucocutaneous telangiectases, and visceral AVMs and caused by mutations in one of several genes, including activin receptor–like kinase 1 (ALK1). It remains unknown why and how selective blood vessels form AVMs, and there have been technical limitations to observing the initial stages of AVM formation. Here we present in vivo evidence that physiological or environmental factors such as wounds in addition to the genetic ablation are required for Alk1-deficient vessels to develop to AVMs in adult mice. Using the dorsal skinfold window chamber system, we have demonstrated for what we believe to be the first time the entire course of AVM formation in subdermal blood vessels by using intravital bright-field images, hyperspectral imaging, fluorescence recordings of direct arterial flow through the AV shunts, and vascular casting techniques. We believe our data provide novel insights into the pathogenetic mechanisms of HHT and potential therapeutic approaches. PMID:19805914

A 3-tier classification of cerebral arteriovenous malformations. Clinical article.

PubMed

Spetzler, Robert F; Ponce, Francisco A

2011-03-01

The authors propose a 3-tier classification for cerebral arteriovenous malformations (AVMs). The classification is based on the original 5-tier Spetzler-Martin grading system, and reflects the treatment paradigm for these lesions. The implications of this modification in the literature are explored. Class A combines Grades I and II AVMs, Class B are Grade III AVMs, and Class C combines Grades IV and V AVMs. Recommended management is surgery for Class A AVMs, multimodality treatment for Class B, and observation for Class C, with exceptions to the latter including recurrent hemorrhages and progressive neurological deficits. To evaluate whether combining grades is warranted from the perspective of surgical outcomes, the 3-tier system was applied to 1476 patients from 7 surgical series in which results were stratified according to Spetzler-Martin grades. Pairwise comparisons of individual Spetzler-Martin grades in the series analyzed showed the fewest significant differences (p < 0.05) in outcomes between Grades I and II AVMs and between Grades IV and V AVMs. In the pooled data analysis, significant differences in outcomes were found between all grades except IV and V (p = 0.38), and the lowest relative risks were found between Grades I and II (1.066) and between Grades IV and V (1.095). Using the pooled data, the predictive accuracies for surgical outcomes of the 5-tier and 3-tier systems were equivalent (receiver operating characteristic curve area 0.711 and 0.713, respectively). Combining Grades I and II AVMs and combining Grades IV and V AVMs is justified in part because the differences in surgical results between these respective pairs are small. The proposed 3-tier classification of AVMs offers simplification of the Spetzler-Martin system, provides a guide to treatment, and is predictive of outcome. The revised classification not only simplifies treatment recommendations; by placing patients into 3 as opposed to 5 groups, statistical power is markedly increased for series comparisons.

Unruptured Versus Ruptured AVMs: Outcome Analysis from a Multicentric Consecutive Series of 545 Surgically Treated Cases.

PubMed

Cenzato, Marco; Tartara, Fulvio; D'Aliberti, Giuseppe; Bortolotti, Carlo; Cardinale, Francesco; Ligarotti, Gianfranco; Debernardi, Alberto; Fratianni, Alessia; Boccardi, Edoardo; Stefini, Roberto; Zenga, Francesco; Boccaletti, Riccardo; Lanterna, Andrea; Pavesi, Giacomo; Ferroli, Paolo; Sturiale, Carmelo; Ducati, Alessandro; Cardia, Andrea; Piparo, Maurizio; Valvassori, Luca; Piano, Mariangela

2018-02-01

Recent literature strongly challenged indications to perform preventive surgery in unruptured arteriovenous malformation (AVM) claiming that invasive AVM treatment is associated with a significant risk of complications and thus conservative management may be a preferable alternative in many patients. On the other hand, the recent improvement of surgical instrumentation and treatment strategies (both surgical and interventional) yielded better outcomes than those achieved only a decade ago. Therefore, even among specialists, a wide variety of opinions, concerning the treatment of unruptured AVM, can be found. This multicenter retrospective study analyzes a consecutive series of 545 surgically treated AVMs in 10 different hospitals in Italy. Patients with AVMs treated after hemorrhage had an unfavorable (modified Rankin Scale score >1) outcome in more than one third (37.69%) of the cases. Conversely, with proper indications, unruptured AVMs treated preventively have a good outcome in 93.8% of cases, increasing to 95.7%, with no death, if only Spetzler-Martin grades 1-3 are considered (P < 0.05). Outcomes on discharge significantly (P < 0.05) improve at 6 months with the disappearance of many of the initial neurologic deficits that turn out to be transient. In unruptured low-risk AVMs (Spetzler-Martin grades 1-3), over time, the risk of surgery-associated neurologic deficits becomes lower than that linked to spontaneous hemorrhage, with a crossover point at 6.5 years. Because the average bleeding age is less than 45 years, preventive surgery can be advocated to safeguard the patient and overcome the risks associated with the natural history of AVMs. Copyright © 2017 Elsevier Inc. All rights reserved.

Onyx resorbtion with AVM recanalization after complete AVM obliteration.

PubMed

Bauer, Andrew M; Bain, Mark D; Rasmussen, Peter A

2015-06-01

Brain arteriovenous malformations (BAVM) are some of the most complex lesions treated by clinical neuroscientists. The recent publication of the ARUBA trial, showing higher complication rates with treatment compared with the natural history over a short period of follow-up, puts even more pressure on the physician to achieve complete BAVM eradication without complication. These lesions are often treated by multimodality therapy with some combination of endovascular embolization, radiosurgery, and microsurgical resection; however, multimodality therapy involves the additive risk of procedural complication with each procedure. While surgical resection has long been accepted as monotherapy with good cure rates, staged pre-operative endovascular embolization has facilitated microsurgical resection with lower blood loss. Endovascular embolization is more often utilized in conjunction with surgical resection, and often the portions of the AVM and feeders that are completely embolized with Onyx or glue may not be surgically resected since they have been "internally obliterated." We present a case where the AVM was preoperatively embolized with Onyx and subsequently partially surgically resected. Post-operative angiography showed complete obliteration or "cure" of the AVM with no filling of the nidus or early venous drainage. The patient presented 12 months later with seizures and imaging showed volume loss in the residual Onyx cast and recanalization of the AVM nidus. The patient subsequently underwent repeat resection with complete removal of the residual AVM and Onyx cast. To our knowledge this is the first published report of volume loss within the Onyx cast leading to recanalization of the AVM nidus. This suggests that extreme care should be taken with partial resection of the AVM nidus or with embolization for cure, as late recanalization may occur. © The Author(s) 2015.

Onyx resorbtion with AVM recanalization after complete AVM obliteration

PubMed Central

Bain, Mark D; Rasmussen, Peter A

2015-01-01

Brain arteriovenous malformations (BAVM) are some of the most complex lesions treated by clinical neuroscientists. The recent publication of the ARUBA trial, showing higher complication rates with treatment compared with the natural history over a short period of follow-up, puts even more pressure on the physician to achieve complete BAVM eradication without complication. These lesions are often treated by multimodality therapy with some combination of endovascular embolization, radiosurgery, and microsurgical resection; however, multimodality therapy involves the additive risk of procedural complication with each procedure. While surgical resection has long been accepted as monotherapy with good cure rates, staged pre-operative endovascular embolization has facilitated microsurgical resection with lower blood loss. Endovascular embolization is more often utilized in conjunction with surgical resection, and often the portions of the AVM and feeders that are completely embolized with Onyx or glue may not be surgically resected since they have been “internally obliterated.” We present a case where the AVM was preoperatively embolized with Onyx and subsequently partially surgically resected. Post-operative angiography showed complete obliteration or “cure” of the AVM with no filling of the nidus or early venous drainage. The patient presented 12 months later with seizures and imaging showed volume loss in the residual Onyx cast and recanalization of the AVM nidus. The patient subsequently underwent repeat resection with complete removal of the residual AVM and Onyx cast. To our knowledge this is the first published report of volume loss within the Onyx cast leading to recanalization of the AVM nidus. This suggests that extreme care should be taken with partial resection of the AVM nidus or with embolization for cure, as late recanalization may occur. PMID:26015523

Management of Arteriovenous Malformations Associated with Developmental Venous Anomalies: A Literature Review and Report of 2 Cases.

PubMed

Zhang, Michael; Connolly, Ian D; Teo, Mario K; Yang, George; Dodd, Robert; Marks, Michael; Zuccarello, Mario; Steinberg, Gary K

2017-10-01

Classification of cerebrovascular malformations has revealed intermediary lesions that warrant further review owing to their unusual presentation and management. We present 2 cases of arteriovenous malformation (AVM) associated with a developmental venous anomaly (DVA), and discuss the efficacy of previously published management strategies. Two cases of AVMs associated with DVA were identified, and a literature search for published cases between 1980 and 2016 was conducted. Patient demographic data and clinical features were documented. In case 1, a 29-year-old female presenting with parenchymal hemorrhage and left homonymous hemianopia was found to have a right parieto-occipital AVM fed from the anterior cerebral, middle cerebral, and posterior cerebral arteries, with major venous drainage to the superior sagittal sinus. In case 2, imaging in a 34-year-old female evaluated for night tremors and incontinence revealed a left parietal AVM with venous drainage to the superior sagittal sinus. Including our 2 cases, 22 cases of coexisting AVMs and DVAs have been reported in the literature. At presentation, 68% had radiographic evidence of hemorrhage. Stereotactic radiosurgery was performed in 7 cases, embolization in 6 cases, surgical resection in 4 cases, and multimodal therapy in 5 cases. Radiography at follow-up demonstrated successful AVM obliteration in 67% of cases (12 of 18). Patients with coexisting AVMs and DVAs tend to have a hemorrhagic presentation. Contrary to traditional AVM management, in these cases it is important to preserve the draining vein via the DVA to ensure a safe, sustained circulatory outflow of the associated brain parenchyma while achieving safe AVM obliteration. Copyright © 2017 Elsevier Inc. All rights reserved.

Interobserver Agreement on Arteriovenous Malformation Diffuseness Using Digital Subtraction Angiography.

PubMed

Braileanu, Maria; Yang, Wuyang; Caplan, Justin M; Lin, Li-Mei; Radvany, Martin G; Tamargo, Rafael J; Huang, Judy

2016-11-01

Arteriovenous malformation (AVM) diffuseness has been shown to be prognostic of treatment outcomes. We assessed interobserver agreement of AVM diffuseness among physicians of different specialty and training backgrounds using digital subtraction angiography (DSA). All research protocols were approved by the institutional review board for this retrospective chart review. In a single-blinded setting, 2 attending neurosurgeons, 1 attending interventional neuroradiologist, and 1 senior neurosurgical resident rated 80 DSA views of 36 AVMs as either compact or diffuse. Individual interobserver agreement and subgroup agreement were analyzed using κ agreement and intraclass correlation coefficient. Disagreement regarding AVM diffuseness occurred in 43.8% of all DSA views (n = 80). Interobserver κ agreement on AVM diffuseness using DSA views among 4 physicians ranged from fair (κ = 0.40 [95% confidence interval (CI) = 0.22-0.58]) to substantial (κ = 0.65 [95% CI = 0.48-0.81]), whereas total intraclass correlation coefficient was 0.81 (95% CI = 0.73-0.87). For the 36 AVMs, κ agreement ranged from fair (κ = 0.36 [95% CI = 0.13-0.60]) to moderate (κ = 0.57 [95% CI = 0.35-0.79]), whereas intraclass correlation coefficient among all 4 physicians was 0.68 (95% CI = 0.47-0.82). Moderate agreement on AVM diffuseness (n = 80) was found between attending and resident assessments (κ = 0.57 [95% CI = 0.39-0.75]) and between neurosurgeon and interventional neuroradiologist assessments (κ = 0.55 [95% CI = 0.37-0.73]). Agreement of individual physicians on AVM diffuseness varies from fair to substantial. Objective and three-dimensional measures of AVM diffuseness should be developed for consistent clinical application. Copyright © 2016 Elsevier Inc. All rights reserved.

Treatment of Brain Arteriovenous Malformations with Hemodynamic Aneurysms: A Series of 131 Consecutive Cases.

PubMed

Eliava, Shalva; Dmitriev, Alexey; Shekhtman, Oleg; Yakovlev, Sergey; Kheireddin, Ali; Pilipenko, Yuriy

2018-02-01

The natural history of hemodynamic aneurysms (HAs) associated with brain arteriovenous malformations (AVMs) remains controversial, with no single approach to treatment. The purpose of this study was to justify preventive treatment tactics for HAs that pose an increased risk of rupture based on hemodynamic studies demonstrating hypertension in the afferent bed after AVM exclusion. This retrospective analysis included 131 of 1740 patients (8%) with brain AVMs and at least 1 aneurysm treated at Burdenko Neurosurgical Institute between 2000 and 2016. Treatment consisted of microsurgery, endovascular interventions, or a combination of modalities. Patients were evaluated with the modified Rankin Scale before and after treatment. A total of 205 aneurysms were discovered. Multiple HAs were found in 46 patients (35%), and were significantly more often associated with posterior fossa AVMs; in addition, most were distally located. There was no difference in the incidence of hemorrhage between proximal and distal HAs. Microsurgical treatment was marked by high radicalism; 85% of HAs and 94% of AVMs were totally excluded based on control studies. In 10 cases, aneurysms were found after AVM removal, including 4 de novo aneurysms. In 1 case, the aneurysm regressed after AVM treatment. The mortality rate was 2.3%. Preoperative imaging should be carefully examined for associated aneurysms before and after surgical treatment. Our data suggests that HA exclusion, either as the first step or simultaneously with AVM treatment, is most beneficial to patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Contemporary management of spinal AVFs and AVMs: lessons learned from 110 cases.

PubMed

Rangel-Castilla, Leonardo; Russin, Jonathan J; Zaidi, Hasan A; Martinez-Del-Campo, Eduardo; Park, Min S; Albuquerque, Felipe C; McDougall, Cameron G; Nakaji, Peter; Spetzler, Robert F

2014-09-01

Spinal arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs) are rare, complex spinal vascular lesions that are challenging to manage. Recently, understanding of these lesions has increased thanks to neuroimaging technology. Published reports of surgical results and clinical outcome are limited to small series. The authors present a large contemporary series of patients with spinal AVFs and AVMs who were treated at Barrow Neurological Institute in Phoenix, Arizona. Retrospective detailed review of a prospective vascular database was performed for all patients with spinal AVFs and AVMs treated between 2000 and 2013. Patient demographic data, AVF and AVM characteristics, surgical results, clinical outcomes, complications, and long-term follow-up were reviewed. Between 2000 and 2013, 110 patients (57 male and 53 female) underwent obliteration of spinal AVFs and AVMs. The mean age at presentation was 42.3 years (range 18 months-81 years). There were 44 patients with AVFs and 66 with AVMs. The AVM group included 27 intramedullary, 21 conus medullaris, 12 metameric, and 6 extradural. The most common location was thoracic spine (61%), followed by cervical (22.7%), lumbar (14.5%), and sacral (1.8%). The most common presenting signs and symptoms included paresis/paralysis (75.5%), paresthesias (60%), pain (51.8%), bowel/bladder dysfunction (41.8%), and myelopathy (36.4%). Evidence of rupture was seen in 26.4% of patients. Perioperative embolization was performed in 42% of patients. Resection was performed in 95 patients (86.4%). Embolization alone was the only treatment in 14 patients (12.7%). One patient was treated with radiosurgery alone. Angiographically verified AVF and AVM obliteration was achieved in 92 patients (83.6%). At a mean follow-up duration of 30.5 months (range 1-205 months), 43 patients (97.7%) with AVFs and 57 (86.4%) with AVMs remained functionally independent (McCormick Scale scores ≤ 2). Perioperative complications were seen in 8 patients (7%). No deaths occurred. Temporary neurological deficits were observed in 27 patients (24.5%). These temporary deficits recovered 6-8 weeks after treatment. Recurrence was identified in 6 patients (13.6%) with AVFs and 10 (15.2%) with AVMs. Spinal AVFs and AVMs are complex lesions that should be considered for surgical obliteration. Over the last several decades the authors have changed surgical strategies and management to achieve better clinical outcomes. Transient neurological deficit postoperatively is a risk associated with intervention; however, clinical outcomes appear to exceed the natural history based on patients' ability to recover during the follow-up period. Due to the recurrence rate associated with these lesions, long-term follow-up is required.

HealthCyberMap: a semantic visual browser of medical Internet resources based on clinical codes and the human body metaphor.

PubMed

Kamel Boulos, Maged N; Roudsari, Abdul V; Carso N, Ewart R

2002-12-01

HealthCyberMap (HCM-http://healthcybermap.semanticweb.org) is a web-based service for healthcare professionals and librarians, patients and the public in general that aims at mapping parts of the health information resources in cyberspace in novel ways to improve their retrieval and navigation. HCM adopts a clinical metadata framework built upon a clinical coding ontology for the semantic indexing, classification and browsing of Internet health information resources. A resource metadata base holds information about selected resources. HCM then uses GIS (Geographic Information Systems) spatialization methods to generate interactive navigational cybermaps from the metadata base. These visual cybermaps are based on familiar medical metaphors. HCM cybermaps can be considered as semantically spatialized, ontology-based browsing views of the underlying resource metadata base. Using a clinical coding scheme as a metric for spatialization ('semantic distance') is unique to HCM and is very much suited for the semantic categorization and navigation of Internet health information resources. Clinical codes ensure reliable and unambiguous topical indexing of these resources. HCM also introduces a useful form of cyberspatial analysis for the detection of topical coverage gaps in the resource metadata base using choropleth (shaded) maps of human body systems.

A Retrograde Transvenous Embolization Technique with Balloon-Assisted Arterial Aspiration for a Peripheral Arteriovenous Malformation with a Venous Pouch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhara, Asako, E-mail: kuhara-asako@med.kurume-u.ac.jp; Tanaka, Norimitsu; Koganemaru, Masamichi

Management of arteriovenous malformations (AVMs) is challenging, and there is no consensus regarding either the ideal approach or the treatment timing. Percutaneous embolization is the most frequent approach currently used and is considered the first-line technique for AVMs. There is an ongoing discussion about the best technical approach to embolize AVMs. AVMs associated with a dominant outflow vein (DOV) are rare. Embolization of both the DOV and the nidus is considered more effective. Herein, we report a novel technique of transvenous embolization of a DOV under negative pressure from an arterial balloon catheter in a case of a peripheral AVM.more » This technique allows the embolization of the DOV and the nidus retrogradely.« less

Effect of the embolization material in the dose calculation for stereotactic radiosurgery of arteriovenous malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galván de la Cruz, Olga Olinca; Lárraga-Gutiérrez, José Manuel, E-mail: jlarraga@innn.edu.mx; Laboratorio de Física Médica, Instituto Nacional de Neurología y Neurocirugía

2013-07-01

It is reported in the literature that the material used in an embolization of an arteriovenous malformation (AVM) can attenuate the radiation beams used in stereotactic radiosurgery (SRS) up to 10% to 15%. The purpose of this work is to assess the dosimetric impact of this attenuating material in the SRS treatment of embolized AVMs, using Monte Carlo simulations assuming clinical conditions. A commercial Monte Carlo dose calculation engine was used to recalculate the dose distribution of 20 AVMs previously planned with a pencil beam dose calculation algorithm. Dose distributions were compared using the following metrics: average, minimal and maximummore » dose of AVM, and 2D gamma index. The effect in the obliteration rate was investigated using radiobiological models. It was found that the dosimetric impact of the embolization material is less than 1.0 Gy in the prescription dose to the AVM for the 20 cases studied. The impact in the obliteration rate is less than 4.0%. There is reported evidence in the literature that embolized AVMs treated with SRS have low obliteration rates. This work shows that there are dosimetric implications that should be considered in the final treatment decisions for embolized AVMs.« less

Augmented reality in the surgery of cerebral arteriovenous malformations: technique assessment and considerations.

PubMed

Cabrilo, Ivan; Bijlenga, Philippe; Schaller, Karl

2014-09-01

Augmented reality technology has been used for intraoperative image guidance through the overlay of virtual images, from preoperative imaging studies, onto the real-world surgical field. Although setups based on augmented reality have been used for various neurosurgical pathologies, very few cases have been reported for the surgery of arteriovenous malformations (AVM). We present our experience with AVM surgery using a system designed for image injection of virtual images into the operating microscope's eyepiece, and discuss why augmented reality may be less appealing in this form of surgery. N = 5 patients underwent AVM resection assisted by augmented reality. Virtual three-dimensional models of patients' heads, skulls, AVM nidi, and feeder and drainage vessels were selectively segmented and injected into the microscope's eyepiece for intraoperative image guidance, and their usefulness was assessed in each case. Although the setup helped in performing tailored craniotomies, in guiding dissection and in localizing drainage veins, it did not provide the surgeon with useful information concerning feeder arteries, due to the complexity of AVM angioarchitecture. The difficulty in intraoperatively conveying useful information on feeder vessels may make augmented reality a less engaging tool in this form of surgery, and might explain its underrepresentation in the literature. Integrating an AVM's hemodynamic characteristics into the augmented rendering could make it more suited to AVM surgery.

Clinical values of intraoperative indocyanine green fluorescence video angiography with Flow 800 software in cerebrovascular surgery.

PubMed

Ye, Xun; Liu, Xing-Ju; Ma, Li; Liu, Ling-Tong; Wang, Wen-Lei; Wang, Shuo; Cao, Yong; Zhang, Dong; Wang, Rong; Zhao, Ji-Zong; Zhao, Yuan-Li

2013-11-01

Microscope-integrated near-infrared indocyanine green video angiography (ICG-VA) has been used in neurosurgery for a decade. This study aimed to assess the value of intraoperative indocyanine green (ICG) video angiography with Flow 800 software in cerebrovascular surgery and to discover its hemodynamic features and changes of cerebrovascular diseases during surgery. A total of 87 patients who received ICG-VA during various surgical procedures were enrolled in this study. Among them, 45 cases were cerebral aneurysms, 25 were cerebral arteriovenous malformations (AVMs), and 17 were moyamoya disease (MMD). A surgical microscope integrating an infrared fluorescence module was used to confirm the residual aneurysms and blocking of perforating arteries in aneurysms. Feeder arteries, draining veins, and normal cortical vessels were identified by the time delay color mode of Flow 800 software. Hemodynamic parameters were recorded. All data were analyzed by SPSS version 18.0 (SPSS Inc., USA). T-test was used to analyze the hemodynamic features of AVMs and MMDs, the influence on peripheral cortex after resection in AVMs, and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in MMDs. The visual delay map obtained by Flow 800 software had more advantages than the traditional playback mode in identifying the feeder arteries, draining veins, and their relations to normal cortex vessels. The maximum fluorescence intensity (MFI) and the slope of ICG fluorescence curve of feeder arteries and draining veins were higher than normal peripheral vessels (MFI: 584.24±85.86 vs. 382.94 ± 91.50, slope: 144.95 ± 38.08 vs. 69.20 ± 13.08, P < 0.05). The arteriovenous transit time in AVM was significantly shorter than in normal cortical vessels ((0.60 ± 0.27) vs. (2.08 ± 1.42) seconds, P < 0.05). After resection of AVM, the slope of artery in the cortex increased, which reflected the increased cerebral flow. In patients with MMD, after STA-MCA bypass, cortex perfusion of corresponding branches region increased and local cycle time became shorter. Intraoperative ICG video angiography combined with hemodynamic parameter analysis obtained by Flow 800 software appears to be useful for intraoperative monitoring of regional cerebral blood flow in cerebrovascular disease.

Awake craniotomy for excision of arteriovenous malformations? A qualitative comparison study with stereotactic radiosurgery.

PubMed

Chan, David Yuen Chung; Chan, Danny Tat Ming; Zhu, Cannon Xian Lun; Kan, Patricia Kwok Yee; Ng, Amelia Yikjin; Hsieh, Yi-Pin Sonia; Abrigo, Jill; Poon, Wai Sang; Wong, George Kwok Chu

2018-05-01

Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS). The objective of this study was to perform a qualitative comparison of the treatment outcome of awake AVM excision versus SRS. We conducted a 13-year retrospective review of AVM excision under awake craniotomy performed at Prince of Wales Hospital, Hong Kong, from 2003 to 2016. Patients' presentation, Spetzler-Martin (SM) grading, rate of obliteration and complication were reviewed and analyzed with the modified radiosurgery-based AVM score (RS score). Six patients had excision of AVM under awake mapping during this period of time. Two were SM Grade II and four were SM Grade III. Five located at the peri-rolandic region while one at the temporal language area. None had failed mapping. Five out of six achieved complete obliteration (83.3%). Qualitative comparative analysis had revealed better treatment outcome with awake AVM excision as compared to SRS with the obliteration rate of 100% versus 96% for RS score ≤1.00, 100% versus 78% for RS score 1.01-1.50, and 66% versus 50% for RS score >2.00 respectively. In conclusion, awake mapping and excision of AVMs at the eloquent area is feasible. Qualitative comparative analysis had revealed higher obliteration rate with awake AVM excision as compared to SRS. Copyright © 2018 Elsevier Ltd. All rights reserved.

Endovascular balloon-assisted embolization of intracranial and cervical arteriovenous malformations using dual-lumen coaxial balloon microcatheters and Onyx: initial experience.

PubMed

Jagadeesan, Bharathi D; Grigoryan, Mikayel; Hassan, Ameer E; Grande, Andrew W; Tummala, Ramachandra P

2013-12-01

Ethylene vinyl alcohol copolymer (Onyx) is widely used for the embolization of arteriovenous malformations (AVMs) of the brain, head, and neck. Balloon-assisted Onyx embolization may provide additional unique advantages in the treatment of AVMs in comparison with traditional catheter-based techniques. To report our initial experience in performing balloon-assisted AVM embolization for brain and neck AVMs with the use of the new Scepter-C and Scepter-XC coaxial dual-lumen balloon microcatheters. Balloon-assisted transarterial embolization was performed in a series of 7 patients with AVMs (4 with brain AVMs, 1 with a dural arteriovenous fistula, and 2 with neck AVMs) by using Onyx delivered through the lumen of Scepter-C or Scepter XC coaxial balloon microcatheters. Following the initial balloon-catheter navigation into a feeding artery and the subsequent inflation of the balloon, the embolization was performed by using Onyx 18, Onyx 34, or both. A total of 12 embolization sessions were performed via 17 arterial feeders in these 7 patients. In 1 patient, there was an arterial perforation from the inflation of the balloon; in all others, the embolization goals were successfully achieved with no adverse events. The balloon microcatheters showed excellent navigability, and there were no problems with retrieval or with the repeated inflation and deflation of the balloons. A proximal Onyx plug, which is crucial in many AVM embolizations, was not necessary with this technique. Additionally, fluoroscopy and procedural times seemed lower with this technique compared with conventional embolization methods.

An approach to the symbolic representation of brain arteriovenous malformations for management and treatment planning.

PubMed

Orlowski, Piotr; Mahmud, Imran; Kamran, Mudassar; Summers, Paul; Noble, Alison; Ventikos, Yiannis; Byrne, James V

2014-03-01

There is currently no standardised approach to arteriovenous malformation (AVM) reporting. Existing AVM classification systems focuses on angioarchitectural features and omit haemodynamic, anatomical and topological parameters intuitively used by therapists. We introduce a symbolic vocabulary to represent the state of an AVM of the brain at different stages of treatment. The vocabulary encompasses the main anatomic and haemodynamic features of interest in treatment planning and provides shorthand symbols to represent the interventions themselves in a schematic representation. The method was presented to 50 neuroradiologists from 14 countries during a workshop and graded 7.34 ± 1.92 out of ten for its usefulness as means of standardising and facilitating communication between clinicians and allowing comparisons between AVM cases. Feedback from the survey was used to revise the method and improve its completeness. For an AVM test case, participants were asked to produce a conventional written report and subsequently a diagrammatic report. The two required, on average, 6.19 ± 2.05 and 5.09 ± 3.01 min, respectively. Eighteen participants said that producing the diagram changed the way they thought about the AVM test case. Introduced into routine practice, the diagrams would represent a step towards a standardised approach to AVM reporting with consequent benefits for comparative analysis and communication as well as for identifying best treatment strategies.

Incidental occlusion of anterior spinal artery due to Onyx reflux in embolization of spinal type II arteriovenous malformation.

PubMed

Kim, Joohyun; Lee, Jang-Bo; Cho, Tai-Hyoung; Hur, Junseok W

2017-05-01

Onyx embolization is one of the standard treatments for brain arteriovenous malformations (AVMs) and is a promising method for spinal AVMs as well. Its advantages have been emphasized, and few complications have been reported with Onyx embolization in spinal AVMs. Here, we report an incidental anterior spinal artery (ASA) occlusion due to Onyx reflux during embolization of a spinal type II AVM. A 15-year-old boy presented with weakness in both upper and lower extremities. Magnetic resonance imaging and spinal angiogram revealed a spinal type II AVM with two feeders including the right vertebral artery (VA) and the right deep cervical artery. Onyx embolization was performed gradually from the VA to the deep cervical artery and an unexpected Onyx reflux to the ASA was observed during the latter stage deep cervical artery embolization. Post-operative quadriplegia and low cranial nerves (CN) dysfunction were observed. Rehabilitation treatment was performed and the patient showed marked improvement of neurologic deterioration at 1-year follow-up. Onyx is an effective treatment choice for spinal AVMs. However, due to the small vasculature of the spine compared to the brain, the nidus is rapidly packed with a small amount of Onyx, which allows Onyx reflux to unexpected vessels. Extreme caution is required and dual-lumen balloon catheter could be considered for Onyx embolization in spinal AVMs treatment.

Clinical features of avian vacuolar myelinopathy in American coots

USGS Publications Warehouse

Larsen, R.S.; Nutter, F.B.; Augspurger, T.; Rocke, T.E.; Tomlinson, L.; Thomas, N.J.; Stoskopf, M.K.

2002-01-01

Objectivea??To characterize clinical features of avian vacuolar myelinopathy (AVM) in American coots. Designa??Case-control study. Animalsa??26 AVM-affected American coots and 12 unaffected coots. Proceduresa??Complete physical, neurologic, hematologic, and plasma biochemical evaluations were performed. Affected coots received supportive care. All coots died or were euthanatized, and AVM status was confirmed via histopathologic findings. Resultsa??3 severely affected coots were euthanatized immediately after examination. Seventeen affected coots were found dead within 7 days of admission, but 5 affected coots survived > 21 days and had signs of clinical recovery. Abnormal physical examination findings appeared to be related to general debilitation. Ataxia (88%), decreased withdrawal reflexes (88%), proprioceptive deficits (81%), decreased vent responses (69%), beak or tongue weakness (42%), and head tremors (31%), as well as absent pupillary light responses (46%), anisocoria (15%), apparent blindness (4%), nystagmus (4%), and strabismus (4%) were detected. Few gross abnormalities were detected at necropsy, but histologically, all AVM-affected coots had severe vacuolation of white matter of the brain. None of the control coots had vacuolation. Conclusions and Clinical Relevancea??Although there was considerable variability in form and severity of clinical neurologic abnormalities, clinical signs common in AVM-affected birds were identified. Clinical recovery of some AVM-affected coots can occur when supportive care is administered. Until the etiology is identified, caution should be exercised when rehabilitating and releasing coots thought to be affected by AVM.

Paraspinal arteriovenous malformation Onyx embolization via an Ascent balloon.

PubMed

Martínez-Galdámez, Mario; Rodriguez-Arias, Carlos A; Utiel, Elena; Arreba, Emilio; Gonzalo, Miguel; Arenillas, Juan F

2013-03-22

Purely extradural lumbar spinal arteriovenous malformations (AVMs) are rare lesions that have diverse presentations and imaging features. The treatment of a symptomatic high flow paraspinal AVM with multiple feeders remains a challenge. We report the first use of an Ascent balloon (dual lumen balloon catheter) to deliver Onyx with excellent penetration to a paraspinal AVM.

Paraspinal arteriovenous malformation Onyx embolization via an Ascent balloon

PubMed Central

Martínez-Galdámez, Mario; Rodriguez-Arias, Carlos A; Utiel, Elena; Arreba, Emilio; Gonzalo, Miguel; Arenillas, Juan F

2013-01-01

Purely extradural lumbar spinal arteriovenous malformations (AVMs) are rare lesions that have diverse presentations and imaging features. The treatment of a symptomatic high flow paraspinal AVM with multiple feeders remains a challenge. We report the first use of an Ascent balloon (dual lumen balloon catheter) to deliver Onyx with excellent penetration to a paraspinal AVM. PMID:23524491

Paraspinal arteriovenous malformation Onyx embolization via an Ascent balloon.

PubMed

Martínez-Galdámez, Mario; Rodriguez-Arias, Carlos A; Utiel, Elena; Arreba, Emilio; Gonzalo, Miguel; Arenillas, Juan F

2014-04-01

Purely extradural lumbar spinal arteriovenous malformations (AVMs) are rare lesions that have diverse presentations and imaging features. The treatment of a symptomatic high flow paraspinal AVM with multiple feeders remains a challenge. We report the first use of an Ascent balloon (dual lumen balloon catheter) to deliver Onyx with excellent penetration to a paraspinal AVM.

Benefit of cone-beam computed tomography angiography in acute management of angiographically undetectable ruptured arteriovenous malformations.

PubMed

Rahal, Jason P; Malek, Adel M

2013-10-01

Ruptured arteriovenous malformations (AVMs) are a frequent cause of intracerebral hemorrhage (ICH). In some cases, compression from the associated hematoma in the acute setting can partially or completely occlude an AVM, making it invisible on conventional angiography techniques. The authors report on the successful use of cone-beam CT angiography (CBCT-A) to precisely identify the underlying angioarchitecture of ruptured AVMs that are not visible on conventional angiography. Three patients presented with ICH for which they underwent examination with CBCT-A in addition to digital subtraction angiography and other imaging modalities, including MR angiography and CT angiography. All patients underwent surgical evacuation due to mass effect from the hematoma. Clinical history, imaging studies, and surgical records were reviewed. Hematoma volumes were calculated. In all 3 cases, CBCT-A demonstrated detailed anatomy of an AVM where no lesion or just a suggestion of a draining vein had been seen with other imaging modalities. Magnetic resonance imaging demonstrated enhancement in 1 patient; CT angiography demonstrated a draining vein in 1 patient; 2D digital subtraction angiography and 3D rotational angiography demonstrated a suggestion of a draining vein in 2 cases and no finding in the third. In the 2 patients in whom CBCT-A was performed prior to surgery, the demonstrated AVM was successfully resected without evidence of a residual lesion. In the third patient, CBCT-A allowed precise targeting of the AVM nidus using Gamma Knife radiosurgery. Cone-beam CT angiography should be considered in the evaluation and subsequent treatment of ICH due to ruptured AVMs. In cases in which the associated hematoma compresses the AVM nidus, CBCT-A can have higher sensitivity and anatomical accuracy than traditional angiographic modalities, including digital subtraction angiography.

Long-term Outcomes With Planned Multistage Reduced Dose Repeat Stereotactic Radiosurgery for Treatment of Inoperable High-Grade Arteriovenous Malformations: An Observational Retrospective Cohort Study.

PubMed

Marciscano, Ariel E; Huang, Judy; Tamargo, Rafael J; Hu, Chen; Khattab, Mohamed H; Aggarwal, Sameer; Lim, Michael; Redmond, Kristin J; Rigamonti, Daniele; Kleinberg, Lawrence R

2017-07-01

There is no consensus regarding the optimal management of inoperable high-grade arteriovenous malformations (AVMs). This long-term study of 42 patients with high-grade AVMs reports obliteration and adverse event (AE) rates using planned multistage repeat stereotactic radiosurgery (SRS). To evaluate the efficacy and safety of multistage SRS with treatment of the entire AVM nidus at each treatment session to achieve complete obliteration of high-grade AVMs. Patients with high-grade Spetzler-Martin (S-M) III-V AVMs treated with at least 2 multistage SRS treatments from 1989 to 2013. Clinical outcomes of obliteration rate, minor/major AEs, and treatment characteristics were collected. Forty-two patients met inclusion criteria (n = 26, S-M III; n = 13, S-M IV; n = 3, S-M V) with a median follow-up was 9.5 yr after first SRS. Median number of SRS treatment stages was 2, and median interval between stages was 3.5 yr. Twenty-two patients underwent pre-SRS embolization. Complete AVM obliteration rate was 38%, and the median time to obliteration was 9.7 yr. On multivariate analysis, higher S-M grade was significantly associated ( P = .04) failure to achieve obliteration. Twenty-seven post-SRS AEs were observed, and the post-SRS intracranial hemorrhage rate was 0.027 events per patient year. Treatment of high-grade AVMs with multistage SRS achieves AVM obliteration in a meaningful proportion of patients with acceptable AE rates. Lower obliteration rates were associated with higher S-M grade and pre-SRS embolization. This approach should be considered with caution, as partial obliteration does not protect from hemorrhage. Copyright © 2017 by the Congress of Neurological Surgeons

Avian vacuolar myelinopathy: a newly recognized fatal neurologic disease of eagles, waterfowl, and other birds

USGS Publications Warehouse

Fischer, John R.; Lewis, L.A.; Augspurger, T.; Rocke, T.E.

2002-01-01

Wildlife biologists and health specialists have been frustrated by a long list of negative findings in their AVM investigations, however studies continue to provide pieces of information to aid the determination of the cause and its source. Available data indicated that AVM may have been present since at least 1990, occurs in at least five states, has been documented during October through April at sites of wintering populations of birds where the exposure apparently occurs, and has killed at least 90 bald eagles. Birds with AVM have difficulty or inability to fly, swim, walk, or perch, but there has been resolution of clinical signs in some affected coots. The list of affected species continues to grow, but remains confined to wild avians, including bald eagle, American coot, great horned owl, killdeer, Canada goose, mallard, ring-necked duck and bufflehead. The effects of the AVM agent on mammals, including human beings, are unknown. A neurotoxicant of manmade or natural origin is the suspected cause of AVM because no infectious disease agents, such as viruses, bacteria, parasites and prions, have been found, and the lesion and epizootiology of AVM resemble those of toxicoses. Additionally it is documented, experimentally, that exposure to raptors can occur through ingestion of infected coots. Collaborative studies will continue in the effort to identify the cause of AVM, its geographic distribution, and the range of species susceptibility. Hopefully, this information can be used to identify measures that might be taken to reduce the impact of AVM on the wildlife resource. Multiple agencies, institutions, and individuals must rely on each other's expertise in the multidisciplinary approach to this problem, persevere in their efforts and take advantage of serendipity that presents itself during investigations of this newly recognized cause of wild bird mortality.

Visualizing and Validating Metadata Traceability within the CDISC Standards.

PubMed

Hume, Sam; Sarnikar, Surendra; Becnel, Lauren; Bennett, Dorine

2017-01-01

The Food & Drug Administration has begun requiring that electronic submissions of regulated clinical studies utilize the Clinical Data Information Standards Consortium data standards. Within regulated clinical research, traceability is a requirement and indicates that the analysis results can be traced back to the original source data. Current solutions for clinical research data traceability are limited in terms of querying, validation and visualization capabilities. This paper describes (1) the development of metadata models to support computable traceability and traceability visualizations that are compatible with industry data standards for the regulated clinical research domain, (2) adaptation of graph traversal algorithms to make them capable of identifying traceability gaps and validating traceability across the clinical research data lifecycle, and (3) development of a traceability query capability for retrieval and visualization of traceability information.

Visualizing and Validating Metadata Traceability within the CDISC Standards

PubMed Central

Hume, Sam; Sarnikar, Surendra; Becnel, Lauren; Bennett, Dorine

2017-01-01

The Food & Drug Administration has begun requiring that electronic submissions of regulated clinical studies utilize the Clinical Data Information Standards Consortium data standards. Within regulated clinical research, traceability is a requirement and indicates that the analysis results can be traced back to the original source data. Current solutions for clinical research data traceability are limited in terms of querying, validation and visualization capabilities. This paper describes (1) the development of metadata models to support computable traceability and traceability visualizations that are compatible with industry data standards for the regulated clinical research domain, (2) adaptation of graph traversal algorithms to make them capable of identifying traceability gaps and validating traceability across the clinical research data lifecycle, and (3) development of a traceability query capability for retrieval and visualization of traceability information. PMID:28815125

Spontaneous thrombosis of the main draining vein revealing an unruptured brain arteriovenous malformation.

PubMed

Cao, Catherine; Sourour, Nader; Reina, Vincent; Nouet, Aurélien; Di Maria, Federico; Chiras, Jacques; Cornu, Philippe; Clarençon, Frédéric

2015-04-01

Haemorrhage is the most frequent revealing condition of brain arteriovenous malformations (bAVMs). We report a rare case of unruptured parietal bAVM revealed by spontaneous thrombosis of the main draining vein, responsible for a focal neurological deficit. The bAVM was embolized in emergency conditions; complete regression of the neurological symptoms was observed within five days after the embolization. Potential mechanisms of such spontaneous thrombosis of the bAVM's main drainage pathway as well as an exhaustive review of the literature concerning this rare revealing condition are presented and discussed. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Multiple cerebral arteriovenous malformations associated to rostral hypoplasia of the superior sagittal sinus: case report.

PubMed

TORNè, Ramon; Molina Jaque, Felipe A; Rodriguez-Hernandez, Ana; Arikan, Fuat; Lopez-Bermeo, Diego; Tomasello, Alejandro

2016-06-07

Multiple cerebral arteriovenous malformations (AVMs) are a rare occurrence usually associated with defined genetic disorders or a family history of cerebrovascular disease. The remaining cases cannot be associated to a genetic pathogenesis and are considered idiopathic. We report an extremely unusual case nor genetic neither idiopathic, but linked to an anatomical intracranial venous variation. The patient presented two independent frontal AVMs associated with rostral hypoplasia of the superior sagittal sinus. This anatomical variation may have induced frontal venous hypertension (VHT) triggering the development of the two AVMs. Throughout this intriguing case, we discuss the role of VHT in AVM development.

Surgery or gamma -knife for the treatment of arteriovenous malformations?

PubMed

Shigeno, T; Atsuchi, M; Tanaka, J; Goto, K; Ogata, N

2000-09-01

Decision making for either surgery or gamma-knife for the treatment of arteriovenous malformations (AVMs) cannot be uniform. The skill of the neurosurgeon in operating on AVMs is now being compared with that of the gamma-knife. The decision varies from case to case and is to be taken by the neurosurgeon. This report presents three cases in which such decision making was not easy. Case 1 was a non-ruptured cingulate AVM of 2.5 cm diameter in the cingulate cortex. The operative field was anticipated to be very narrow between the parietal bridging veins. Case 2 was a tiny ruptured AVM in the speech-motor area which was buried underneath the cortex. Case 3 was a large ruptured thalamo-stiriate-capsular AVM with feeders from the anterior and posterior choroidal arteries. All cases were operated without serious morbidity. A combination of pre-operative intravascular surgery (cases 1 and 3) or postoperative gamma-knife (case 3) was adopted. In conclusion, there is no unitary rule to decide on surgery or gamma-knife for the treatment of AVMs. It depends on what good or harm the responsible surgeon or the gamma-knife does.

Failure to transmit avian vacuolar myelinopathy to mallard ducks

USGS Publications Warehouse

Larsen, R.S.; Nutter, F.B.; Augspurger, T.; Rocke, T.E.; Thomas, N.J.; Stoskopf, M.K.

2003-01-01

Avian vacuolar myelinopathy (AVM) is a neurologic disease that has been diagnosed in free-ranging birds in the southeastern United States. Bald eagles (Haliaeetus leuocephalus), American coots (Fulica americana), and mallards (Anas platyrhynchos) have been affected. Previous investigations have not determined the etiology of this disease. In November and December 2002, we attempted to induce AVM in game-farmed mallards through four, 7-day exposure trials. Mallards were housed in six groups of eight, with two of these groups serving as controls. One group was housed with AVM-affected coots; one group was tube fed daily with water from the lake where affected coots were captured; one group was tube fed daily with aquatic vegetation (Hydrilla verticillata) from the same lake; and another group was tube fed daily with sediment from the lake. No ducks exhibited clinical neurologic abnormalities consistent with AVM and no evidence of AVM was present at histopathologic examination of brain tissue. Although limitations in sample size, quantity of individual doses, frequency of dose administration, duration of exposure, and timing of these trials restrict the interpretation of the findings, AVM was not readily transmitted by direct contact, water, hydrilla, or sediment in this investigation.

Discovery of Marine Datasets and Geospatial Metadata Visualization

NASA Astrophysics Data System (ADS)

Schwehr, K. D.; Brennan, R. T.; Sellars, J.; Smith, S.

2009-12-01

NOAA's National Geophysical Data Center (NGDC) provides the deep archive of US multibeam sonar hydrographic surveys. NOAA stores the data as Bathymetric Attributed Grids (BAG; http://www.opennavsurf.org/) that are HDF5 formatted files containing gridded bathymetry, gridded uncertainty, and XML metadata. While NGDC provides the deep store and a basic ERSI ArcIMS interface to the data, additional tools need to be created to increase the frequency with which researchers discover hydrographic surveys that might be beneficial for their research. Using Open Source tools, we have created a draft of a Google Earth visualization of NOAA's complete collection of BAG files as of March 2009. Each survey is represented as a bounding box, an optional preview image of the survey data, and a pop up placemark. The placemark contains a brief summary of the metadata and links to directly download of the BAG survey files and the complete metadata file. Each survey is time tagged so that users can search both in space and time for surveys that meet their needs. By creating this visualization, we aim to make the entire process of data discovery, validation of relevance, and download much more efficient for research scientists who may not be familiar with NOAA's hydrographic survey efforts or the BAG format. In the process of creating this demonstration, we have identified a number of improvements that can be made to the hydrographic survey process in order to make the results easier to use especially with respect to metadata generation. With the combination of the NGDC deep archiving infrastructure, a Google Earth virtual globe visualization, and GeoRSS feeds of updates, we hope to increase the utilization of these high-quality gridded bathymetry. This workflow applies equally well to LIDAR topography and bathymetry. Additionally, with proper referencing and geotagging in journal publications, we hope to close the loop and help the community create a true “Geospatial Scholar” infrastructure.

A challenging entity of endovascular embolization with ONYX for brainstem arteriovenous malformation: Experience from 13 cases.

PubMed

Jin, Hengwei; Liu, Zhan; Chang, Qing; Chen, Chang; Ge, Huijian; Lv, Xianli; Li, Youxiang

2017-10-01

Objective Brainstem arteriovenous malformations (AVMs) are rare lesions with a high risk of intracranial hemorrhage and are challenging to treat. We present our experience of endovascular embolization with Onyx in these aggressive lesions. Materials and methods Between 2007 and 2016, 13 patients with brainstem AVMs were embolized with Onyx at our center. Twelve patients presented with intracranial hemorrhage and one with headache. Retrospective examinations of patient demographics, clinical presentation, angiographic features, treatment modalities, postoperative complications and outcomes were carried out. Results The AVMs were in the midbrain in 10 patients (one anterior and nine posterior or dorsal), in the posterior pons in two and pontomedullary in one. Complete occlusion was achieved in three patients. Gamma knife radiosurgery was performed in six patients who were near-completely or partially embolized. Postoperative complications, including five cases of ischemia and one case of hemorrhage, resulted in four cases of neurological deterioration and two deaths. Clinical follow-up was obtained in 10 patients at a mean period of 45.2 months (range 3 to 93 months). During the follow-up, good clinical outcomes were observed in seven patients with posterior or dorsal midbrain AVMs, and one patient with a posterior pons AVM that was partially occluded died of intracranial hemorrhage. Conclusion Endovascular embolization for brainstem AVM with Onyx is a technical challenge and the reflux of Onyx may cause severe complications. Individualized treatment is needed based on the specific subtype of brainstem AVM.

European consensus conference on unruptured brain AVMs treatment (Supported by EANS, ESMINT, EGKS, and SINCH).

PubMed

Cenzato, Marco; Boccardi, Edoardo; Beghi, Ettore; Vajkoczy, Peter; Szikora, Istvan; Motti, Enrico; Regli, Luca; Raabe, Andreas; Eliava, Shalva; Gruber, Andreas; Meling, Torstein R; Niemela, Mika; Pasqualin, Alberto; Golanov, Andrey; Karlsson, Bengt; Kemeny, Andras; Liscak, Roman; Lippitz, Bodo; Radatz, Matthias; La Camera, Alessandro; Chapot, René; Islak, Civan; Spelle, Laurent; Debernardi, Alberto; Agostoni, Elio; Revay, Martina; Morgan, Michael K

2017-06-01

In December of 2016, a Consensus Conference on unruptured AVM treatment, involving 24 members of the three European societies dealing with the treatment of cerebral AVMs (EANS, ESMINT, and EGKS) was held in Milan, Italy. The panel made the following statements and general recommendations: (1) Brain arteriovenous malformation (AVM) is a complex disease associated with potentially severe natural history; (2) The results of a randomized trial (ARUBA) cannot be applied equally for all unruptured brain arteriovenous malformation (uBAVM) and for all treatment modalities; (3) Considering the multiple treatment modalities available, patients with uBAVMs should be evaluated by an interdisciplinary neurovascular team consisting of neurosurgeons, neurointerventionalists, radiosurgeons, and neurologists experienced in the diagnosis and treatment of brain AVM; (4) Balancing the risk of hemorrhage and the associated restrictions of everyday activities related to untreated unruptured AVMs against the risk of treatment, there are sufficient indications to treat unruptured AVMs grade 1 and 2 (Spetzler-Martin); (5) There may be indications for treating patients with higher grades, based on a case-to-case consensus decision of the experienced team; (6) If treatment is indicated, the primary strategy should be defined by the multidisciplinary team prior to the beginning of the treatment and should aim at complete eradication of the uBAVM; (7) After having considered the pros and cons of a randomized trial vs. a registry, the panel proposed a prospective European Multidisciplinary Registry.

A new material for tissue engineered vagina reconstruction: Acellular porcine vagina matrix.

PubMed

Zhang, Jing-Kun; Du, Run-Xuan; Zhang, Lin; Li, Ya-Nan; Zhang, Ming-Le; Zhao, Shuo; Huang, Xiang-Hua; Xu, Yan-Fang

2017-07-01

Acellular matrix materials have been widely used to repair various tissues and organs. According to the plastic principle, when a part of the body is lost, it should be replaced with a similar material. Therefore, the use of a homologous organ-specific acellular vaginal tissue in vagina reconstruction repair surgery may show good results. However, the acellular vagina matrix (AVM) form large vertebrates is difficult to isolate. In this study, we described a multistep method to prepare porcine AVM and evaluated the efficacy of acellularization. We also investigated the biomechanical properties, biological activity elements, and biocompatibility of the porcine AVM. We then used this material to reconstruct a rat vagina and performed further morphologic and functional analyses. Small intestinal submucosa (SIS), which is a commonly used acellular matrix material, was used in a control group. Histological examination, DNA content analysis, and agarose gel electrophoresis revealed that the decellularization procedure was effective. The AVM had acceptable biomechanical properties and sufficient growth factor production (VEGF, FGF, TGF-β1, and PDGF-BB) compared with that of the SIS. Subcutaneous transplantation in rats showed that the AVM had good biocompatibility. The tissue-engineered vagina using the AVM more resembled normal-appearing tissue than did that using SIS following morphologic and functional analyses. The AVM has great potential for application in vaginal reconstructive surgery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1949-1959, 2017. © 2017 Wiley Periodicals, Inc.

Extension modules for storage, visualization and querying of genomic, genetic and breeding data in Tripal databases

PubMed Central

Lee, Taein; Cheng, Chun-Huai; Ficklin, Stephen; Yu, Jing; Humann, Jodi; Main, Dorrie

2017-01-01

Abstract Tripal is an open-source database platform primarily used for development of genomic, genetic and breeding databases. We report here on the release of the Chado Loader, Chado Data Display and Chado Search modules to extend the functionality of the core Tripal modules. These new extension modules provide additional tools for (1) data loading, (2) customized visualization and (3) advanced search functions for supported data types such as organism, marker, QTL/Mendelian Trait Loci, germplasm, map, project, phenotype, genotype and their respective metadata. The Chado Loader module provides data collection templates in Excel with defined metadata and data loaders with front end forms. The Chado Data Display module contains tools to visualize each data type and the metadata which can be used as is or customized as desired. The Chado Search module provides search and download functionality for the supported data types. Also included are the tools to visualize map and species summary. The use of materialized views in the Chado Search module enables better performance as well as flexibility of data modeling in Chado, allowing existing Tripal databases with different metadata types to utilize the module. These Tripal Extension modules are implemented in the Genome Database for Rosaceae (rosaceae.org), CottonGen (cottongen.org), Citrus Genome Database (citrusgenomedb.org), Genome Database for Vaccinium (vaccinium.org) and the Cool Season Food Legume Database (coolseasonfoodlegume.org). Database URL: https://www.citrusgenomedb.org/, https://www.coolseasonfoodlegume.org/, https://www.cottongen.org/, https://www.rosaceae.org/, https://www.vaccinium.org/

Ruptured Aneurysm of Intercostal Arteriovenous Malformation Associated With Neurofibromatosis Type 1: A Case Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hyung Jun; Seon, Hyun Ju, E-mail: sunaura@hanmail.net; Choi, Song

Intercostal arteriovenous malformations (AVM) are rare, with most being secondary to trauma or iatrogenic therapeutic procedures. Only one case of presumably congenital AVM has been reported. Here we report the first case of a ruptured aneurysm of intercostal AVM associated with neurofibromatosis type 1 in a 32-year-old woman who experienced hypovolemic shock caused by massive hemothorax.

Transcatheter Embolization of a Large Symptomatic Pelvic Arteriovenous Malformation with Glubran 2 Acrylic Glue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandini, R.; Angelopoulos, G., E-mail: giorginos78@msn.com; Konda, D.

A young patient affected by a pelvic arteriovenous malformation (pAVM) with recurrent episodes of hematuria following exercise, underwent transcatheter embolization using Glubran 2 acrylic glue (GEM, Viareggio, Italy). All branches of the pAVM were successfully occluded. The patient showed prompt resolution of symptoms and persistent occlusion of the pAVM at the 6 month follow-up.

Soluble FLT1 Gene Therapy Alleviates Brain Arteriovenous Malformation Severity

PubMed Central

Zhu, Wan; Shen, Fanxia; Mao, Lei; Zhan, Lei; Kang, Shuai; Sun, Zhengda; Nelson, Jeffrey; Zhang, Rui; Zou, Dingquan; McDougall, Cameron M.; Lawton, Michael T.; Vu, Thiennu H.; Wu, Zhijian; Scaria, Abraham; Colosi, Peter; Forsayeth, John; Su, Hua

2017-01-01

Background and Purpose Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current therapies are associated with high morbidities. Excessive vascular endothelial growth factor (VEGF) has been implicated in bAVM pathophysiology. Because soluble FLT1 binds to VEGF with high affinity, we tested intravenous (IV) delivery of an adeno-associated viral vector serotype 9 expressing soluble FLT1 (AAV9-sFLT1) to alleviate the bAVM phenotype. Methods Two mouse models were used. Model 1: bAVM was induced in R26CreER;Eng2f/2f mice through global Eng gene deletion and brain focal angiogenic stimulation; AAV2-sFLT02 (an AAV expressing a shorter form of sFLT1) was injected into the brain at the time of model induction, and AAV9-sFLT1, IV-injected eight weeks after. Model 2: SM22αCre;Eng2f/2f mice had a 90% occurrence of spontaneous bAVM at 5 weeks of age and 50% mortality at 6 weeks; AAV9-sFLT1 was IV-delivered into 4–5-week-old mice. Tissue samples were collected four weeks after AAV9-sFLT1 delivery. Results AAV2-sFLT02 inhibited bAVM formation and AAV9-sFLT1 reduced abnormal vessels in Model 1 (GFP vs sFLT1: 3.66 ± 1.58/200 vessels vs 1.98 ± 1.29, p<0.05). AAV9-sFLT1 reduced the occurrence of bAVM (GFP vs sFLT1: 100% vs 36%) and mortality [GFP vs sFLT1: 57% (12/22 mice) vs 24% (4/19 mice), p<0.05] in Model 2. Kidney and liver function did not change significantly. Minor liver inflammation was found in 56% of AAV9-sFLT1-treated Model 1 mice. Conclusion By applying a regulated mechanism to restrict sFLT1 expression to bAVM, AAV9-sFLT1 can potentially be developed into a safer therapy to reduce the bAVM severity. PMID:28325846

Multistage stereotactic radiosurgery for large cerebral arteriovenous malformations using the Gamma Knife platform.

PubMed

Ding, Chuxiong; Hrycushko, Brian; Whitworth, Louis; Li, Xiang; Nedzi, Lucien; Weprin, Bradley; Abdulrahman, Ramzi; Welch, Babu; Jiang, Steve B; Wardak, Zabi; Timmerman, Robert D

2017-10-01

Radiosurgery is an established technique to treat cerebral arteriovenous malformations (AVMs). Obliteration of larger AVMs (> 10-15 cm 3 or diameter > 3 cm) in a single session is challenging with current radiosurgery platforms due to toxicity. We present a novel technique of multistage stereotactic radiosurgery (SRS) for large intracranial arteriovenous malformations (AVM) using the Gamma Knife system. Eighteen patients with large (> 10-15 cm 3 or diameter > 3 cm) AVMs, which were previously treated using a staged SRS technique on the Cyberknife platform, were retrospectively selected for this study. The AVMs were contoured and divided into 3-8 subtargets to be treated sequentially in a staged approach at half to 4 week intervals. The prescription dose ranged from 15 Gy to 20 Gy, depending on the subtarget number, volume, and location. Gamma Knife plans using multiple collimator settings were generated and optimized. The coordinates of each shot from the initial plan covering the total AVM target were extracted based on their relative positions within the frame system. The shots were regrouped based on their location with respect to the subtarget contours to generate subplans for each stage. The delivery time of each shot for a subtarget was decay corrected with 60 Co for staging the treatment course to generate the same dose distribution as that planned for the total AVM target. Conformality indices and dose-volume analysis were performed to evaluate treatment plans. With the shot redistribution technique, the composite dose for the multistaged treatment of multiple subtargets is equivalent to the initial plan for total AVM target. Gamma Knife plans resulted in an average PTV coverage of 96.3 ± 0.9% and a PITV of 1.23 ± 0.1. The resulting Conformality indices, V 12Gy and R 50 dose spillage values were 0.76 ± 0.05, 3.4 ± 1.8, and 3.1 ± 0.5 respectively. The Gamma Knife system can deliver a multistaged conformal dose to treat large AVMs when correcting for translational setup errors of each shot at each staged treatment. © 2017 American Association of Physicists in Medicine.

XAFS Data Interchange: A single spectrum XAFS data file format.

PubMed

Ravel, B; Newville, M

We propose a standard data format for the interchange of XAFS data. The XAFS Data Interchange (XDI) standard is meant to encapsulate a single spectrum of XAFS along with relevant metadata. XDI is a text-based format with a simple syntax which clearly delineates metadata from the data table in a way that is easily interpreted both by a computer and by a human. The metadata header is inspired by the format of an electronic mail header, representing metadata names and values as an associative array. The data table is represented as columns of numbers. This format can be imported as is into most existing XAFS data analysis, spreadsheet, or data visualization programs. Along with a specification and a dictionary of metadata types, we provide an application-programming interface written in C and bindings for programming dynamic languages.

XAFS Data Interchange: A single spectrum XAFS data file format

NASA Astrophysics Data System (ADS)

Ravel, B.; Newville, M.

2016-05-01

We propose a standard data format for the interchange of XAFS data. The XAFS Data Interchange (XDI) standard is meant to encapsulate a single spectrum of XAFS along with relevant metadata. XDI is a text-based format with a simple syntax which clearly delineates metadata from the data table in a way that is easily interpreted both by a computer and by a human. The metadata header is inspired by the format of an electronic mail header, representing metadata names and values as an associative array. The data table is represented as columns of numbers. This format can be imported as is into most existing XAFS data analysis, spreadsheet, or data visualization programs. Along with a specification and a dictionary of metadata types, we provide an application-programming interface written in C and bindings for programming dynamic languages.

Recurrence of a paediatric arteriovenous malformation 9 years postcomplete excision: case report and review of literature

PubMed Central

McCarthy, Claire; Kaliaperumal, Chandrasekaran; O'Sullivan, Michael

2012-01-01

Cerebral arteriovenous malformations (AVMs) are a common congenital vascular anomaly, which often present in both children and adults. Surgery is considered curative once postoperative angiography confirms the absence of vessels. We describe a 6-year-old girl, who had a Spetzler-Martin Grade II AVM resected successfully, in which a recurrent AVM was detected on routine follow-up over 9 years post excision. The aetiopathogenesis of this rare occurrence with a review of literature is discussed. Long-term postoperative follow-up in the form of MRI/MR angiogram is recommended for all fully resected AVMs in the paediatric age group, anticipating the possibility of future recurrence. PMID:23010462

Effective use of metadata in the integration and analysis of multi-dimensional optical data

NASA Astrophysics Data System (ADS)

Pastorello, G. Z.; Gamon, J. A.

2012-12-01

Data discovery and integration relies on adequate metadata. However, creating and maintaining metadata is time consuming and often poorly addressed or avoided altogether, leading to problems in later data analysis and exchange. This is particularly true for research fields in which metadata standards do not yet exist or are under development, or within smaller research groups without enough resources. Vegetation monitoring using in-situ and remote optical sensing is an example of such a domain. In this area, data are inherently multi-dimensional, with spatial, temporal and spectral dimensions usually being well characterized. Other equally important aspects, however, might be inadequately translated into metadata. Examples include equipment specifications and calibrations, field/lab notes and field/lab protocols (e.g., sampling regimen, spectral calibration, atmospheric correction, sensor view angle, illumination angle), data processing choices (e.g., methods for gap filling, filtering and aggregation of data), quality assurance, and documentation of data sources, ownership and licensing. Each of these aspects can be important as metadata for search and discovery, but they can also be used as key data fields in their own right. If each of these aspects is also understood as an "extra dimension," it is possible to take advantage of them to simplify the data acquisition, integration, analysis, visualization and exchange cycle. Simple examples include selecting data sets of interest early in the integration process (e.g., only data collected according to a specific field sampling protocol) or applying appropriate data processing operations to different parts of a data set (e.g., adaptive processing for data collected under different sky conditions). More interesting scenarios involve guided navigation and visualization of data sets based on these extra dimensions, as well as partitioning data sets to highlight relevant subsets to be made available for exchange. The DAX (Data Acquisition to eXchange) Web-based tool uses a flexible metadata representation model and takes advantage of multi-dimensional data structures to translate metadata types into data dimensions, effectively reshaping data sets according to available metadata. With that, metadata is tightly integrated into the acquisition-to-exchange cycle, allowing for more focused exploration of data sets while also increasing the value of, and incentives for, keeping good metadata. The tool is being developed and tested with optical data collected in different settings, including laboratory, field, airborne, and satellite platforms.

Generalizing the extensibility of a dynamic geometry software

NASA Astrophysics Data System (ADS)

Herceg, Đorđe; Radaković, Davorka; Herceg, Dejana

2012-09-01

Plug-and-play visual components in a Dynamic Geometry Software (DGS) enable development of visually attractive, rich and highly interactive dynamic drawings. We are developing SLGeometry, a DGS that contains a custom programming language, a computer algebra system (CAS engine) and a graphics subsystem. The basic extensibility framework on SLGeometry supports dynamic addition of new functions from attribute annotated classes that implement runtime metadata registration in code. We present a general plug-in framework for dynamic importing of arbitrary Silverlight user interface (UI) controls into SLGeometry at runtime. The CAS engine maintains a metadata storage that describes each imported visual component and enables two-way communication between the expressions stored in the engine and the UI controls on the screen.

PI3 kinase inhibition improves vascular malformations in mouse models of hereditary haemorrhagic telangiectasia.

PubMed

Ola, Roxana; Dubrac, Alexandre; Han, Jinah; Zhang, Feng; Fang, Jennifer S; Larrivée, Bruno; Lee, Monica; Urarte, Ana A; Kraehling, Jan R; Genet, Gael; Hirschi, Karen K; Sessa, William C; Canals, Francesc V; Graupera, Mariona; Yan, Minhong; Young, Lawrence H; Oh, Paul S; Eichmann, Anne

2016-11-29

Activin receptor-like kinase 1 (ALK1) is an endothelial serine-threonine kinase receptor for bone morphogenetic proteins (BMPs) 9 and 10. Inactivating mutations in the ALK1 gene cause hereditary haemorrhagic telangiectasia type 2 (HHT2), a disabling disease characterized by excessive angiogenesis with arteriovenous malformations (AVMs). Here we show that inducible, endothelial-specific homozygous Alk1 inactivation and BMP9/10 ligand blockade both lead to AVM formation in postnatal retinal vessels and internal organs including the gastrointestinal (GI) tract in mice. VEGF and PI3K/AKT signalling are increased on Alk1 deletion and BMP9/10 ligand blockade. Genetic deletion of the signal-transducing Vegfr2 receptor prevents excessive angiogenesis but does not fully revert AVM formation. In contrast, pharmacological PI3K inhibition efficiently prevents AVM formation and reverts established AVMs. Thus, Alk1 deletion leads to increased endothelial PI3K pathway activation that may be a novel target for the treatment of vascular lesions in HHT2.

De novo development of a cerebral arteriovenous malformation following radiation therapy: Case report and an update to classical arteriovenous malformation nomenclature.

PubMed

Koch, Matthew J; Agarwalla, Pankaj K; Stapleton, Christopher J; Ogilvy, Christopher S; Loeffler, Jay S

2016-06-01

Cerebral arteriovenous malformations (AVM) are traditionally considered primary congenital lesions that result from embryological aberrations in vasculogenesis. Recent insights, however, suggest that these lesions may be secondary to a vascular insult such as ischemia or trauma. Herein, the authors present a rare case of a secondary cerebral AVM, occurring in a young girl who received prior cranial radiation therapy. At age 3years, she underwent surgical resection, chemotherapy, and photon radiation therapy for treatment of a fourth ventricular ependymoma. At age 19years, she developed new onset seizures and was found to have a left medial temporal lobe AVM. Her seizures were managed successfully with anti-epileptic medications and the AVM was treated with proton radiation therapy. This case highlights a rare but possible vascular sequela of radiation therapy and adds to the growing body of evidence that cerebral AVM may arise as secondary lesions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Increasing the international visibility of research data by a joint metadata schema

NASA Astrophysics Data System (ADS)

Svoboda, Nikolai; Zoarder, Muquit; Gärtner, Philipp; Hoffmann, Carsten; Heinrich, Uwe

2017-04-01

The BonaRes Project ("Soil as a sustainable resource for the bioeconomy") was launched in 2015 to promote sustainable soil management and to avoid fragmentation of efforts (Wollschläger et al., 2016). For this purpose, an IT infrastructure is being developed to upload, manage, store, and provide research data and its associated metadata. The research data provided by the BonaRes data centre are, in principle, not subject to any restrictions on reuse. For all research data considerable standardized metadata are the key enablers for the effective use of these data. Providing proper metadata is often viewed as an extra burden with further work and resources consumed. In our lecture we underline the benefits of structured and interoperable metadata like: accessibility of data, discovery of data, interpretation of data, linking data and several more and we counter these advantages with the effort of time, personnel and further costs. Building on this, we describe the framework of metadata in BonaRes combining the standards of OGC for description, visualization, exchange and discovery of geodata as well as the schema of DataCite for the publication and citation of this research data. This enables the generation of a DOI, a unique identifier that provides a permanent link to the citable research data. By using OGC standards, data and metadata become interoperable with numerous research data provided via INSPIRE. It enables further services like CSW for harvesting WMS for visualization and WFS for downloading. We explain the mandatory fields that result from our approach and we give a general overview about our metadata architecture implementation. Literature: Wollschläger, U; Helming, K.; Heinrich, U.; Bartke, S.; Kögel-Knabner, I.; Russell, D.; Eberhardt, E. & Vogel, H.-J.: The BonaRes Centre - A virtual institute for soil research in the context of a sustainable bio-economy. Geophysical Research Abstracts, Vol. 18, EGU2016-9087, 2016.

The VIS-AD data model: Integrating metadata and polymorphic display with a scientific programming language

NASA Technical Reports Server (NTRS)

Hibbard, William L.; Dyer, Charles R.; Paul, Brian E.

1994-01-01

The VIS-AD data model integrates metadata about the precision of values, including missing data indicators and the way that arrays sample continuous functions, with the data objects of a scientific programming language. The data objects of this data model form a lattice, ordered by the precision with which they approximate mathematical objects. We define a similar lattice of displays and study visualization processes as functions from data lattices to display lattices. Such functions can be applied to visualize data objects of all data types and are thus polymorphic.

Embolization of Uterine Arteriovenous Malformations Associated with Cyanotic Congenital Heart Disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wijesekera, N. T., E-mail: n.wijesekera@doctors.net.uk; Padley, S. P.; Kazmi, F.

2009-09-15

Uterine arteriovenous malformation (AVM) is a rare cause of vaginal bleeding and miscarriage. We report two cases of uterine AVMs in patients with a history of complex congenital heart disease, an association that has not been previously described. Both patients were treated by selective uterine artery embolization, a minimally invasive therapy that has revolutionized the management of uterine AVMs, thus offering an alternative to conventional hysterectomy.

Onyx extravasation during embolization of a brain arteriovenous malformation.

PubMed

Ikeda, Hiroyuki; Imamura, Hirotoshi; Agawa, Yuji; Imai, Yukihiro; Tani, Shoichi; Adachi, Hidemitsu; Ishikawa, Tatsuya; Mineharu, Yohei; Sakai, Nobuyuki

2017-04-01

During Onyx embolization to treat brain arteriovenous malformation (AVM), carefully observing the penetration of Onyx to the nidus is important in order to avoid complications such as hemorrhage, ischemia, and difficulty with microcatheter removal. We encountered a case of Onyx extravasation during embolization of a cerebellar AVM confirmed by surgical resection and pathological analysis. The patient was a 44-year-old man with Spetzler-Martin grade I cerebellar AVM who underwent Onyx embolization prior to resection of the brain AVM. While injecting Onyx into the nidus using the "plug-and-push" technique, Onyx extravasation was observed. Onyx injection was paused and subsequently restarted, thereby allowing continuation of embolization. An oblate Onyx cast that was entirely covered in cerebellar tissue was removed during total resection of the AVM, performed the same day. The surgically removed oblate Onyx cast did not contain brain tissue or vessel wall, and immunohistochemical staining against glial fibrillary acidic protein (GFAP) showed Onyx penetration into GFAP-positive cerebellar tissue. Onyx extravasation was confirmed based on intraoperative findings during resection as well as pathological findings. The patient has been followed for four years postoperatively, and adverse events caused by Onyx extravasation have not been observed. Unexpected cast of Onyx, remote from the vascular architecture of the AVM, may represent an intra-parenchymal extravasation.

Onyx extravasation during embolization of a brain arteriovenous malformation

PubMed Central

Imamura, Hirotoshi; Agawa, Yuji; Imai, Yukihiro; Tani, Shoichi; Adachi, Hidemitsu; Ishikawa, Tatsuya; Mineharu, Yohei; Sakai, Nobuyuki

2016-01-01

During Onyx embolization to treat brain arteriovenous malformation (AVM), carefully observing the penetration of Onyx to the nidus is important in order to avoid complications such as hemorrhage, ischemia, and difficulty with microcatheter removal. We encountered a case of Onyx extravasation during embolization of a cerebellar AVM confirmed by surgical resection and pathological analysis. The patient was a 44-year-old man with Spetzler-Martin grade I cerebellar AVM who underwent Onyx embolization prior to resection of the brain AVM. While injecting Onyx into the nidus using the “plug-and-push” technique, Onyx extravasation was observed. Onyx injection was paused and subsequently restarted, thereby allowing continuation of embolization. An oblate Onyx cast that was entirely covered in cerebellar tissue was removed during total resection of the AVM, performed the same day. The surgically removed oblate Onyx cast did not contain brain tissue or vessel wall, and immunohistochemical staining against glial fibrillary acidic protein (GFAP) showed Onyx penetration into GFAP-positive cerebellar tissue. Onyx extravasation was confirmed based on intraoperative findings during resection as well as pathological findings. The patient has been followed for four years postoperatively, and adverse events caused by Onyx extravasation have not been observed. Unexpected cast of Onyx, remote from the vascular architecture of the AVM, may represent an intra-parenchymal extravasation. PMID:27903925

Long-term outcomes of synthetic transobturator nonabsorbable anterior mesh versus anterior colporrhaphy in symptomatic, advanced pelvic organ prolapse surgery.

PubMed

Lo, Tsia-Shu; Pue, Leng Boi; Tan, Yiap Loong; Wu, Pei-Ying

2014-02-01

Anterior vaginal mesh (AVM) combined with sacrospinous ligament fixation (SSF) yields better long-term success rates over anterior colporrhaphy (AC) in advanced pelvic organ prolapse (POP) surgery, with a low rate of mesh-related complications. Medical records of 198 patients who underwent surgery for POP between January 2006 and March 2010 were reviewed retrospectively. Patients' assessment at baseline and third-year postoperative follow-up were analyzed. SSF plus AC or AVM was performed for apical and anterior compartment repair. Primary outcome was objective cure [Pelvic Organ Prolapse Quantification (POP-Q) stage ≤ 1)], and subjective cure defined as negative response to questions 2 and 3 on the POPDI-6. Secondary outcomes were complications, symptoms severity and quality of life as measured with validated questionnaires. Post-operative data were available for 186 patients, 72 in AC group and 114 in AVM group were analyzed. The mean age, parity and operating time in AVM group were significantly higher as compared to AC group. The overall objective and subjective cure rate in AVM group was significantly higher than AC group (90.3 % and 88.6 % versus 73.6 % and 70.8 %, with P value = 0.003 and 0.002 respectively). Mesh exposure rate was 3.5 %. Improvement in both POPDI-6 and PISQ-12 in AVM group was statistically significant compared to AC group. Transobturator synthetic nonabsorbable AVM combined with SSF yielded a favorable and sustainable result over 5 years as compared to traditional AC, both in anatomical and subjective success rate. Mesh related morbidities were low and acceptable.

Radiosurgery for Arteriovenous Malformations and the Impact on Headaches.

PubMed

Bowden, Greg; Cavaleri, Jonathon; Kano, Hideyuki; Monaco, Edward; Niranjan, Ajay; Flickinger, John; Dade Lunsford, L

2017-05-01

Arteriovenous malformations (AVMs) can underlie many diverse neurological signs and symptoms. Headaches are a common presentation that can have a significant impact on quality of life. The authors investigated Gamma Knife ® stereotactic radiosurgery (SRS) outcomes in patients with AVMs and associated headaches. This retrospective study analyzed 102 patients with AVMs who underwent SRS between 1995 and 2013. The patient's headache symptoms led to their AVM diagnosis or developed post hemorrhage of their AVM. Information regarding headache characteristics was obtained from the patient's medical records and at follow-up using a scripted clinical interview. The median imaging follow-up was 61.7 months and clinical follow-up was 89.7 months. The median treatment volume at SRS was 4.1 cm 3 and the median marginal dose was 20 Gy. The actuarial AVM obliteration rate was 60% at 5 years and 78% at 10 years. Patients reported that their overall headache severity decreased by -43.6% and their headache frequency was reduced by -53.4%. Headache reduction was reported in 49.1% of patients at 1 year and 69.5% at 5 years. The median time until improvement was 6.5 months. After SRS, headache medication usage decreased in 29% of patients. Permanent adverse radiation effects after SRS occurred in 3% of patients. Until obliteration was complete, the annual risk of a hemorrhage after SRS was 0.4% per year. Although recall bias related to a retrospective analysis can impact outcomes, headache symptoms associated with AVMs may potentially be decreased or eliminated in a subset of patients treated with Gamma Knife radiosurgery. © 2017 American Headache Society.

Microsurgery Versus Stereotactic Radiosurgery for Brain Arteriovenous Malformations: A Matched Cohort Study.

PubMed

Chen, Ching-Jen; Ding, Dale; Wang, Tony R; Buell, Thomas J; Ilyas, Adeel; Ironside, Natasha; Lee, Cheng-Chia; Kalani, M Yashar; Park, Min S; Liu, Kenneth C; Sheehan, Jason P

2018-05-12

Microsurgery (MS) and stereotactic radiosurgery (SRS) remain the preferred interventions for the curative treatment of brain arteriovenous malformations (AVM), but their relative efficacy remains incompletely defined. To compare the outcomes of MS to SRS for AVMs through a retrospective, matched cohort study. We evaluated institutional databases of AVM patients who underwent MS and SRS. MS-treated patients were matched, in a 1:1 ratio based on patient and AVM characteristics, to SRS-treated patients. Statistical analyses were performed to compare outcomes data between the 2 cohorts. The primary outcome was defined as AVM obliteration without a new permanent neurological deficit. The matched MS and SRS cohorts were each comprised of 59 patients. Both radiological (85 vs 11 mo; P < .001) and clinical (92 vs 12 mo; P < .001) follow-up were significantly longer for the SRS cohort. The primary outcome was achieved in 69% of each cohort. The MS cohort had a significantly higher obliteration rate (98% vs 72%; P = .001), but also had a significantly higher rate of new permanent deficit (31% vs 10%; P = .011). The posttreatment hemorrhage rate was significantly higher for the SRS cohort (10% for SRS vs 0% for MS; P = .027). In subgroup analyses of ruptured and unruptured AVMs, no significant differences between the primary outcomes were observed. For patients with comparable AVMs, MS and SRS afford similar rates of deficit-free obliteration. Nidal obliteration is more frequently achieved with MS, but this intervention also incurs a greater risk of new permanent neurological deficit.

Endovascular treatment of head and neck arteriovenous malformations.

PubMed

Dmytriw, A A; Ter Brugge, K G; Krings, T; Agid, R

2014-03-01

Head and neck arteriovenous malformations (H&N AVM) are associated with considerable clinical and psychosocial burden and present a significant treatment challenge. We evaluated the presentation, response to treatment, and outcome of patients with H&N AVMs treated by endovascular means at our institution. Patients with H&N AVMs treated by endovascular means from 1984 to 2012 were evaluated retrospectively. These included AVMs involving the scalp, orbit, maxillofacial, and upper neck localizations. Patient's clinical files, radiological images, catheter angiograms, and surgical reports were reviewed. Eighty-nine patients with H&N AVMs (46 females, 43 males; 48 small, 41 large) received endovascular therapy. The goals of treatment were curative (n = 30), palliative (n = 34), or presurgical (n = 25). The total number of endovascular treatment sessions was 244 (average of 1.5 per patient). The goal of treatment was met in 92.1 % of cases. Eventual cure was achieved in 42 patients accounting for 58.4 % (52/89) of all patients who underwent treatment for any goal. Twenty-eight of these patients were cured by embolization alone (28/89, 31.4 %) of which 18 were single-hole AVFs. Twenty-four were cured by planned surgical excision after presurgical embolization (24/89, 27 %). Seven patients (7/89, 7.2 %) suffered transient and two (2/89, 2.2 %) permanent endovascular treatment complications. Endovascular treatment is effective for H&N AVMs and relatively safe. It is particularly effective for symptom palliation and presurgical aid. Embolization is curative mostly in small lesions and single-hole fistulas. In patients with large non-curable H&N AVMs, endovascular therapy is often the only palliative option.

The change in heat shock protein expression in avermectin induced neurotoxicity of the pigeon (Columba livia) both in vivo and in vitro.

PubMed

Li, Ming; Wang, Xian-Song; Xu, Feng-Ping; Liu, Shuang; Xu, Shi-Wen; Li, Shu

2014-12-01

The expression of heat shock proteins (Hsps) commonly increases to provide neuroprotection when brain tissues are under stress conditions. Residues of avermectins (AVMs) have neurotoxic effects on a number of non-target organisms. The aim of this study was to investigate the effects of AVM exposure on the expression levels of Hsp 60, Hsp 70 and Hsp 90 for pigeon (Columba livia) neurons both in vivo and in vitro. The results showed that in general, the mRNA and protein levels of Hsps were increased in treated groups relative to control groups after AVM exposure for 30d, 60d and 90d in the cerebrum, cerebellum and optic lobe in vivo. However, AVM exposure had no significant effects on the transcription expression of Hsps for 90d in the optic lobe and decreased the translation expression of Hsps significantly for 90d in the optic lobe. In vitro, the LC50 of avermectin for King pigeon neurons is between 15μgL(-1) and 20μgL(-1). Following AVM (2.5-20μgL(-1)) exposure, the mRNA expression of the 3 Hsps was up-regulated to different degrees. Compared with the control groups, a significant decrease, a remarkable increase and a non-significant change was found in the protein expression of Hsp 60, Hsp 70 and Hsp 90 separately following AVM (2.5-20μgL(-1)) exposure. Based on these results, we conclude that AVM exposure can induce a protective stress response in pigeons by means of promoting the mRNA and protein expression of Hsps under in vivo and in vitro conditions, thus easing the neurotoxic effects of AVM to some extent. Copyright © 2014 Elsevier Inc. All rights reserved.

Awake Craniotomy in Arteriovenous Malformation Surgery: The Usefulness of Cortical and Subcortical Mapping of Language Function in Selected Patients.

PubMed

Gamble, Alexander J; Schaffer, Sarah G; Nardi, Dominic J; Chalif, David J; Katz, Jeffery; Dehdashti, Amir R

2015-11-01

Awake craniotomy for removal of intra-axial lesions is a well-established procedure. Few studies, however, have investigated the usefulness of this approach for resection of arteriovenous malformations adjacent to eloquent language areas. We demonstrate our experience by using cortical stimulation mapping and report for the first time on the usefulness of subcortical stimulation with interrogation of language function during resection of arteriovenous malformations (AVMs) located near language zones. Patients undergoing awake craniotomy for AVMs located in language zones and at least 5 mm away from the closest functional magnetic resonance imaging activation were analyzed. During surgery, cortical bipolar stimulation at 50 Hz, with an intensity of 2 mA, increased to a maximum of 10 mA was performed in the region around the AVM before claiming it negative for language function. In positive language site, the area was restimulated 3 times to confirm the functional deficit. The AVM resection was started based on cortical mapping findings. Further subcortical stimulation performed in concert with speech interrogation by the neuropsychologist continued at key points throughout the resection as feasible. The usefulness of cortical and subcortical stimulation in addition to patient outcomes was analyzed. Between March 2009 and September 2014, 42 brain AVM resections were performed. Four patients with left-sided language zone AVMs underwent awake craniotomy. The AVM locations were fronto-opercular in 2 patients and posterior temporal in 2. The AVM Spetzler-Martin grades were II (2 patients) and III (2 patients). In 1 patient, complete speech arrest was noticed during mapping of the peri-malformation zone, which was not breached during resection. In a second patient who initially demonstrated negative cortical mapping, a speech deficit was noticed during resection and subcortical stimulation. This guided the approach to protect and avoid the sensitive zone. This patient experienced mild postoperative expressive dysphasia that improved to normal within 6 weeks. Complete resection was achieved in all 4 patients. There were no other complications and no permanent neurological morbidity, resulting in good outcome in all 4 patients. Language mapping, both cortical and subcortical during AVM resection, may be valuable in a very select group of AVMs in language zones. Defining safe margins and feedback to the surgeon may provide the highest chances of a surgical cure while minimizing the risk of incurring a language deficit. Copyright © 2015 Elsevier Inc. All rights reserved.

Utility of indocyanine green videoangiography in subcortical arteriovenous malformation resection.

PubMed

Rustemi, Oriela; Scienza, Renato; Della Puppa, Alessandro

2017-07-01

Subcortical arteriovenous malformations (AVMs) are surgically challenging. Localization is crucial for eloquent areas, and complete resection evaluation is uncertain. Indocyanine green videoangiography (ICG-VA) can assist this surgery. An illustrative video of a subcortical frontoparietal bleeding AVM resection assisted by ICG-VA is presented. A bleeding arterial feeder aneurysm was embolized in the acute phase to protect against rebleeding. ICG-VA helped to detect the AVM's superficial arterialized draining vein, distinguishing it from normal cortical veins. This enabled a customized sulcus approach. ICG-VA showed normalized flow through the previously arterialized vein, confirming the AVM's complete resection. This applies when there is a single drainage remaining. The video can be found here: https://youtu.be/L7yJEE66kV0 .

Neurological morbidity and mortality associated with the endovascular treatment of cerebral arteriovenous malformations before and during the Onyx era.

PubMed

Crowley, R Webster; Ducruet, Andrew F; Kalani, M Yashar S; Kim, Louis J; Albuquerque, Felipe C; McDougall, Cameron G

2015-06-01

The widespread implementation of the embolic agent Onyx has changed the endovascular management of cerebral arteriovenous malformations (AVMs). Recent data suggest that outcomes following embolization and resection may have worsened in the Onyx era. It has been hypothesized that there may be increased complications with Onyx embolization and increased surgical aggressiveness in patients treated with Onyx. In this study the authors analyzed their institutional experience with the endovascular treatment of cerebral AVMs prior to and after the introduction of Onyx to determine factors associated with periprocedural neurological morbidity and mortality. A retrospective review was performed of all patients with cerebral AVMs undergoing embolization at the Barrow Neurological Institute from 1995 to 2012. Endovascular treatment of 342 cerebral AVMs was performed over 446 treatment sessions (mean age 37.8 years, range 1-83 years). Clinical presentation included hemorrhage in 47.6%, seizures in 21.9%, headaches in 11.1%, and no symptoms in 10% of cases. The endovascular pretreatment strategy was preoperative in 78.9%, preradiosurgery in 9.1%, palliative in 5.3%, targeted in 4.4%, and curative in 2.3%. The median Spetzler-Martin grade was III. The mean number of arteries embolized was 3.5 (range 0-13 arteries), and the mean number of treatment sessions was 1.3 (range 1-4 sessions). Onyx was used in 105 AVMs (30.7%), and N-butyl cyanoacrylate (NBCA) without Onyx was used in 229 AVMs (67%). AVMs treated with Onyx had a higher mean number of arterial pedicles embolized than did NBCA cases (4.3 ± 2.7 vs 3.2 ± 2.4, respectively; p < 0.001) and a greater number of sessions (1.5 ± 0.7 vs 1.2 ± 0.5, respectively; p < 0.05). Unexpected immediate postprocedural permanent neurological deficits were present in 9.6% of AVMs, while transient deficits were present in 1.8%. There was 1 death (0.3%). Spetzler-Martin grade was not associated with differences in outcome, as permanent neurological deficits were observed in 12%, 9%, 13%, 11%, and 13% of AVMs for Spetzler-Martin Grades I-V, respectively (p = 0.91). The use of Onyx compared with NBCA was not associated with differences in periprocedural morbidity (p = 0.23). This lack of a difference persisted even when controlling for number of arteries and sessions (p = 0.14). Sex was not associated with differences in outcome. Permanent and transient postprocedural neurological deficits were noted in 9.6% and 1.8% of all cases, respectively. AVM grade was not associated with endovascular outcome. Despite the greater number of sessions required and arteries embolized for Onyx cases, there was no statistically significant difference in the risk of neurological deficits following cerebral AVM embolization with Onyx and NBCA.

Web mapping system for complex processing and visualization of environmental geospatial datasets

NASA Astrophysics Data System (ADS)

Titov, Alexander; Gordov, Evgeny; Okladnikov, Igor

2016-04-01

Environmental geospatial datasets (meteorological observations, modeling and reanalysis results, etc.) are used in numerous research applications. Due to a number of objective reasons such as inherent heterogeneity of environmental datasets, big dataset volume, complexity of data models used, syntactic and semantic differences that complicate creation and use of unified terminology, the development of environmental geodata access, processing and visualization services as well as client applications turns out to be quite a sophisticated task. According to general INSPIRE requirements to data visualization geoportal web applications have to provide such standard functionality as data overview, image navigation, scrolling, scaling and graphical overlay, displaying map legends and corresponding metadata information. It should be noted that modern web mapping systems as integrated geoportal applications are developed based on the SOA and might be considered as complexes of interconnected software tools for working with geospatial data. In the report a complex web mapping system including GIS web client and corresponding OGC services for working with geospatial (NetCDF, PostGIS) dataset archive is presented. There are three basic tiers of the GIS web client in it: 1. Tier of geospatial metadata retrieved from central MySQL repository and represented in JSON format 2. Tier of JavaScript objects implementing methods handling: --- NetCDF metadata --- Task XML object for configuring user calculations, input and output formats --- OGC WMS/WFS cartographical services 3. Graphical user interface (GUI) tier representing JavaScript objects realizing web application business logic Metadata tier consists of a number of JSON objects containing technical information describing geospatial datasets (such as spatio-temporal resolution, meteorological parameters, valid processing methods, etc). The middleware tier of JavaScript objects implementing methods for handling geospatial metadata, task XML object, and WMS/WFS cartographical services interconnects metadata and GUI tiers. The methods include such procedures as JSON metadata downloading and update, launching and tracking of the calculation task running on the remote servers as well as working with WMS/WFS cartographical services including: obtaining the list of available layers, visualizing layers on the map, exporting layers in graphical (PNG, JPG, GeoTIFF), vector (KML, GML, Shape) and digital (NetCDF) formats. Graphical user interface tier is based on the bundle of JavaScript libraries (OpenLayers, GeoExt and ExtJS) and represents a set of software components implementing web mapping application business logic (complex menus, toolbars, wizards, event handlers, etc.). GUI provides two basic capabilities for the end user: configuring the task XML object functionality and cartographical information visualizing. The web interface developed is similar to the interface of such popular desktop GIS applications, as uDIG, QuantumGIS etc. Web mapping system developed has shown its effectiveness in the process of solving real climate change research problems and disseminating investigation results in cartographical form. The work is supported by SB RAS Basic Program Projects VIII.80.2.1 and IV.38.1.7.

Balloon-augmented Onyx embolization of cerebral arteriovenous malformations using a dual-lumen balloon: a multicenter experience.

PubMed

Spiotta, Alejandro M; James, Robert F; Lowe, Stephen R; Vargas, Jan; Turk, Aquilla S; Chaudry, M Imran; Bhalla, Tarun; Janjua, Rashid M; Delaney, John J; Quintero-Wolfe, Stacey; Turner, Raymond D

2015-10-01

Conventional Onyx embolization of cerebral arteriovenous malformations (AVMs) requires lengthy procedure and fluoroscopy times to form an adequate 'proximal plug' which allows forward nidal penetration while preventing reflux and non-targeted embolization. We review our experience with balloon-augmented Onyx embolization of cerebral AVMs using a dual-lumen balloon catheter technique designed to minimize these challenges. Retrospectively acquired data for all balloon-augmented cerebral AVM embolizations performed between 2011 and 2014 were obtained from four tertiary care centers. For each procedure, at least one Scepter C balloon catheter was advanced into the AVM arterial pedicle of interest and Onyx embolization was performed through the inner lumen after balloon inflation via the outer lumen. Twenty patients underwent embolization with the balloon-augmented technique over 24 discreet treatment episodes. There were 37 total arterial pedicles embolized with the balloon-augmented technique, a mean of 1.9 per patient (range 1-5). The treated AVMs were heterogeneous in their location and size (mean 3.3±1.6 cm). Mean fluoroscopy time for each procedure was 48±26 min (28 min per embolized pedicle). Two Scepter C balloon catheter-related complications (8.3% of embolization sessions, 5.4% of pedicles embolized) were observed: an intraprocedural rupture of a feeding pedicle and fracture and retention of a catheter fragment. This multicenter experience represents the largest reported series of balloon-augmented Onyx embolization of cerebral AVMs. The technique appears safe and effective in the treatment of AVMs, allowing more efficient and controlled injection of Onyx with a decreased risk of reflux and decreased fluoroscopy times. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Onyx Embolization Before the Surgical Treatment of Grade III Spetzler-Martin Brain Arteriovenous Malformations: Single-Center Experience and Technical Nuances.

PubMed

Luzzi, Sabino; Del Maestro, Mattia; Bongetta, Daniele; Zoia, Cesare; Giordano, Aldo V; Trovarelli, Donatella; Raysi Dehcordi, Sohelia; Galzio, Renato J

2018-05-09

Grade III Spetzler-Martin brain arteriovenous malformations (AVMs) are a specific set of AVMs with high variability in terms of site, size, angioarchitecture, flow dynamics, and involvement of eloquent areas. Surgery preceded by preoperative embolization has been reported as a useful treatment option for these lesions. The aim of this study is to report outcomes and personal experience of combined preoperative Onyx embolization and surgical resection on a consecutive series of grade III brain AVMs. Between 2005 and 2017, 27 grade III AVMs were treated by means of a staged Onyx embolization and subsequent surgical treatment. Site and size of the AVMs, embolization, and surgical specifics as well as complications and outcomes were retrospectively reviewed. All AVMs were supratentorial, 13 of which were hemorrhagic. Mean nidal volume was 19.5 mL. Average embolization sessions were 1.6. Mean embolization-related obliteration rate and morbidity were 28.8% and 3.7%, respectively. Surgery was performed within 3.7 days on average. In our experience, Onyx embolization made the nidus excision easier, facilitated the hemostasis, and contributed to the early identification of the lesion in cases of small or racemose nidus. The surgical obliteration rate was 92.6%. A good overall outcome (modified Rankin Scale score 0-2) was achieved in 70.4% of patients. In our experience, preoperative Onyx embolization helped the surgical management of grade III Spetzler-Martin brain AVMs. Careful evaluation of the angioarchitecture, a tailored strategy in the embolization process, and full cooperation within the neurosurgical-neuroendovascular team are mandatory. Copyright © 2018 Elsevier Inc. All rights reserved.

Angiotensin receptor blockade: a novel approach for symptomatic radiation necrosis after stereotactic radiosurgery.

PubMed

Chowdhary, Mudit; Okwan-Duodu, Derick; Switchenko, Jeffrey M; Press, Robert H; Jhaveri, Jaymin; Buchwald, Zachary S; Zhong, Jim; Chapman, Bhavana V; Bindra, Ranjit S; Contessa, Joseph N; Park, Henry S; Yu, James B; Decker, Roy H; Olson, Jeffrey J; Oyesiku, Nelson M; Abrams, Ross A; Shu, Hui-Kuo G; Curran, Walter J; Crocker, Ian R; Patel, Kirtesh R

2018-01-01

Preclinical evidence suggests angiotensin blockade therapy (ABT) decreases late radiation toxicities. This study aims to investigate the association between ABT and symptomatic radiation necrosis (SRN) following stereotactic radiosurgery (SRS). Resected brain metastases (rBM) and arteriovenous malformation (AVM) patients treated with SRS from 2002 to 2015 were identified. Patients in the ABT cohort were on therapy during SRS and at 1-month follow up. Kaplan Meier method and cumulative incidence model were used to analyze overall survival (OS) and intracranial outcomes. 228 consecutive patients were treated with SRS: 111 with rBM and 117 with AVM. Overall, 51 (22.4%) patients were in the ABT group: 32 (28.8%) in the rBM and 19 (16.2%) in AVM cohorts. Baseline characteristics were similar, except for higher Graded Prognostic Analysis (3-4) in the rBM (ABT: 25.0% vs. non-ABT: 49.0%, p = 0.033) and median age in the AVM (ABT: 51.4 vs. non-ABT: 35.4, p < 0.001) cohorts. In both populations, OS and intracranial efficacy (rBM-local control; AVM-obliteration rates) were statistically similar between the cohorts. ABT was associated with lower 1-year SRN rates in both populations: rBM, 3.1 versus 25.3% (p = 0.003); AVM, 6.7 vs. 14.6% (p = 0.063). On multivariate analysis, ABT was a significant predictive factor for rBM (HR: 0.17; 95% CI 0.03-0.88, p = 0.035), but did not reach statistical significance for AVM (HR: 0.36; 95% CI 0.09-1.52, p = 0.165). ABT use appears to be associated with a reduced risk of SRN following SRS, without detriment to OS or intracranial efficacy. A prospective trial to validate these findings is warranted.

Embolization techniques for high-flow arteriovenous malformations with a dominant outflow vein.

PubMed

Conway, Allan M; Qato, Khalil; Drury, Jennifer; Rosen, Robert J

2015-04-01

The aim of this study was to assess the management and outcomes of arteriovenous malformations (AVMs) with a dominant outflow vein (DOV) treated with retrograde venous embolization. A retrospective review was performed from November 2010 to May 2014 on all patients with a high-flow AVM and associated DOV who underwent transvenous embolization of the DOV. Indications, techniques, complications, and outcomes were reviewed. Fourteen patients (five male; 36%) underwent transvenous embolization of high-flow AVMs with a DOV. Median age was 41.6 years (15.7-65.8 years). The AVM was located on an extremity in eight patients (57%) and in the pelvis in six patients (43%). The indication for the procedure was pain in 11 patients (79%), swelling in 3 patients (21%), a nonhealing wound in 1 patient (7%), and impotence in 1 patient (7%). The median number of prior procedures to treat the AVM was 2.5 (0-13). Transvenous embolization with coils was performed in 13 patients (93%). The Amplatzer vascular plug and Amplatzer septal occluder (St. Jude Medical, St. Paul, Minn) were used in four patients (29%). Concurrent percutaneous puncture embolization of the AVM nidus was used in seven patients (50%) and transcatheter arterial embolization in eight patients (57%). Technical angiographic success was seen in all patients. Five patients (36%) experienced a complete response to treatment, whereas eight (57%) experienced a partial response. Seven patients (50%) required further procedures for residual symptoms. AVMs with a DOV can be successfully treated by a transvenous approach. Percutaneous puncture embolization of the nidus or draining vein and transcatheter arterial embolization may assist in reducing flow. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Incorporate Imaging Characteristics Into an Arteriovenous Malformation Radiosurgery Plan Evaluation Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Pengpeng; Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY; Wu, Leester

Purpose: To integrate imaging performance characteristics, specifically sensitivity and specificity, of magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) into arteriovenous malformation (AVM) radiosurgery planning and evaluation. Methods and Materials: Images of 10 patients with AVMs located in critical brain areas were analyzed in this retrospective planning study. The image findings were first used to estimate the sensitivity and specificity of MRA and DSA. Instead of accepting the imaging observation as a binary (yes or no) mapping of AVM location, our alternative is to translate the image into an AVM probability distribution map by incorporating imagers' sensitivity and specificity,more » and to use this map as a basis for planning and evaluation. Three sets of radiosurgery plans, targeting the MRA and DSA positive overlap, MRA positive, and DSA positive were optimized for best conformality. The AVM obliteration rate (ORAVM) and brain complication rate served as endpoints for plan comparison. Results: In our 10-patient study, the specificities and sensitivities of MRA and DSA were estimated to be (0.95, 0.74) and (0.71, 0.95), respectively. The positive overlap of MRA and DSA accounted for 67.8% {+-} 4.9% of the estimated true AVM volume. Compared with plans targeting MRA and DSA-positive overlap, plans targeting MRA-positive or DSA-positive improved ORAVM by 4.1% {+-} 1.9% and 15.7% {+-} 8.3%, while also increasing the complication rate by 1.0% {+-} 0.8% and 4.4% {+-} 2.3%, respectively. Conclusions: The impact of imagers' quality should be quantified and incorporated in AVM radiosurgery planning and evaluation to facilitate clinical decision making.« less

The correlation between hematoma volume and outcome in ruptured posterior fossa arteriovenous malformations indicates the importance of surgical evacuation of hematomas.

PubMed

Yilmaz, Adem; Musluman, Ahmet Murat; Kanat, Ayhan; Cavusoglu, Halit; Terzi, Yuksel; Aydin, Yunus

2011-01-01

The correlation between hematoma volume and outcome in ruptured arteriovenous malformations (AVM) with accompanying posterior fossa hematoma was retrospectively evaluated. Microsurgery operations were performed on 127 patients with intracranial AVM between January 1998 and January 2009 at our clinic. Fifteen (11.8%) patients were identified as suffering from posterior fossa AVM, and twelve of these patients presented with a cerebellar hematoma. All patients were clinically evaluated according to the following criteria: modified Rankin Scale (mRS) prior to surgery, Spetzler-Martin grade (SMG) of the AVMs, hematoma volume prior to surgery, and mRS following surgery. Postoperative mRS scores were significantly lower than preoperative scores (p=0.0001). Postoperative outcomes were concordant with the SMG of the AVMs (r=0.67, p=0.033), hematoma volume (r=0.537, p=0.072) and preoperative mRS scores (r=0.764, p=0.004). These analyses show that the postoperative mRS score is strongly correlated with a preoperative mRS score, hematoma volume and SMG. Posterior fossa AVMs present an increased risk for hemorrhage and for increased morbidity and mortality. Cases with hematoma should be operated on an urgent basis. We conclude that hematoma volume is a factor that impacts postoperative results and prognosis. SMG and preoperative mRS scores were also correlated with outcome.

Features predictive of brain arteriovenous malformation hemorrhage: extrapolation to a physiologic model.

PubMed

Sahlein, Daniel H; Mora, Paloma; Becske, Tibor; Huang, Paul; Jafar, Jafar J; Connolly, E Sander; Nelson, Peter K

2014-07-01

Although there is generally thought to be a 2% to 4% per annum rupture risk for brain arteriovenous malformations (bAVMs), there is no way to estimate risk for an individual patient. In this retrospective study, patients were eligible who had nidiform bAVMs and underwent detailed pretreatment diagnostic cerebral angiography at our medical center from 1996 to 2006. All patients had superselective microcatheter angiography, and films were reviewed for the purpose of this project. Patient demographics, clinical presentation, and angioarchitectural characteristics were analyzed. A univariate analysis was performed, and angioarchitectural features with potential physiological significance that showed at least a trend toward significance were added to a multivariate logistic regression model. One hundred twenty-two bAVMs met criteria for study entry. bAVMs with single venous drainage anatomy were more likely to present with hemorrhage. In addition, patients with multiple draining veins and a venous stenosis reverted to a risk similar to those with 1 draining vein, whereas those with multiple draining veins and without stenosis had diminished association with hemorrhage presentation. Those bAVMs with associated aneurysms were more likely to present with hemorrhage. These findings were robust in both univariate and multivariate models. The results of this article lead to the first physiological, internally consistent model of individual bAVM hemorrhage risk, where 1 draining vein, venous stenosis, and associated aneurysms increase risk. © 2014 American Heart Association, Inc.

Microsurgical management of a high-grade brain arteriovenous malformation in the central lobe after unsuccessful radiosurgery.

PubMed

de Oliveira, Jean G; Massella, Carlos R; de Holanda, Carlos Vanderlei M; Giudicissi-Filho, Miguel; Borba, Luis A B

2017-07-01

The recommendation for the great majority of high-grade brain arteriovenous malformations (bAVMs) is observation, except for those patients with recurrent hemorrhages, progressive neurological deficits, steal-related symptoms, or AVM-related aneurysms, for whom intervention should be considered. These are general recommendations, and the decision should be made on an individual basis. Surgical resection of an AVM in the central lobe may cause postoperative sensorimotor deficits since this anatomical region includes the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface. The authors present a patient with a ruptured high-grade bAVM in the central lobe who underwent previous surgery for hematoma evacuation and previous radiosurgery, and whose indication for reoperation was proposed based on progressive hemiparesis. Microsurgical resection was possible after a wide frontoparietal craniotomy, which made all the nidus borders accessible. This case illustrates the anatomy and surgical technique for large nidus AVMs in eloquent areas, showing that complete microsurgical resection is possible with good clinical outcome. The video can be found here: https://youtu.be/Cpd1PK6BLIM .

Achieving Sub-Second Search in the CMR

NASA Astrophysics Data System (ADS)

Gilman, J.; Baynes, K.; Pilone, D.; Mitchell, A. E.; Murphy, K. J.

2014-12-01

The Common Metadata Repository (CMR) is the next generation Earth Science Metadata catalog for NASA's Earth Observing data. It joins together the holdings from the EOS Clearing House (ECHO) and the Global Change Master Directory (GCMD), creating a unified, authoritative source for EOSDIS metadata. The CMR allows ingest in many different formats while providing consistent search behavior and retrieval in any supported format. Performance is a critical component of the CMR, ensuring improved data discovery and client interactivity. The CMR delivers sub-second search performance for any of the common query conditions (including spatial) across hundreds of millions of metadata granules. It also allows the addition of new metadata concepts such as visualizations, parameter metadata, and documentation. The CMR's goals presented many challenges. This talk will describe the CMR architecture, design, and innovations that were made to achieve its goals. This includes: * Architectural features like immutability and backpressure. * Data management techniques such as caching and parallel loading that give big performance gains. * Open Source and COTS tools like Elasticsearch search engine. * Adoption of Clojure, a functional programming language for the Java Virtual Machine. * Development of a custom spatial search plugin for Elasticsearch and why it was necessary. * Introduction of a unified model for metadata that maps every supported metadata format to a consistent domain model.

Predicting biomedical metadata in CEDAR: A study of Gene Expression Omnibus (GEO).

PubMed

Panahiazar, Maryam; Dumontier, Michel; Gevaert, Olivier

2017-08-01

A crucial and limiting factor in data reuse is the lack of accurate, structured, and complete descriptions of data, known as metadata. Towards improving the quantity and quality of metadata, we propose a novel metadata prediction framework to learn associations from existing metadata that can be used to predict metadata values. We evaluate our framework in the context of experimental metadata from the Gene Expression Omnibus (GEO). We applied four rule mining algorithms to the most common structured metadata elements (sample type, molecular type, platform, label type and organism) from over 1.3million GEO records. We examined the quality of well supported rules from each algorithm and visualized the dependencies among metadata elements. Finally, we evaluated the performance of the algorithms in terms of accuracy, precision, recall, and F-measure. We found that PART is the best algorithm outperforming Apriori, Predictive Apriori, and Decision Table. All algorithms perform significantly better in predicting class values than the majority vote classifier. We found that the performance of the algorithms is related to the dimensionality of the GEO elements. The average performance of all algorithm increases due of the decreasing of dimensionality of the unique values of these elements (2697 platforms, 537 organisms, 454 labels, 9 molecules, and 5 types). Our work suggests that experimental metadata such as present in GEO can be accurately predicted using rule mining algorithms. Our work has implications for both prospective and retrospective augmentation of metadata quality, which are geared towards making data easier to find and reuse. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Appraising the plasticity of the circle of Willis: a model of hemodynamic modulation in cerebral arteriovenous malformations.

PubMed

Chuang, Yu-Ming; Guo, Wanyuo; Lin, Ching-Po

2010-01-01

Cerebral arteriovenous malformations (AVMs) harbor a network of abnormal vasculatures, namely the nidus between arterial and venous components. The pressure gradient between these two components results in abnormal high-velocity arteriovenous shunts flowing through the nidus and alternate intracranial hemodynamics. This study hypothesizes that the flow patterns of the circle of Willis (CoW) are modulated by the alternation of intracranial hemodynamics occurring in cerebral AVMs. The flow patterns of the CoW before and after AVMs had been corrected and the arteriovenous shunts closed by radiosurgery were assessed to validate the hypothesis. Fifty patients (32 men and 18 women; mean age 35.8 +/- 4.2, range 23-52 years) with cerebral AVMs previously treated by radiosurgery were retrospectively investigated. This investigation used magnetic resonance angiography, performed prior to and after AVM surgery, to assess the CoW flow patterns. The CoW flow patterns in nearly half of the subjects (20/50, 40%) altered after the AVMs had been corrected. The alterations included: (1) decreased size or ceased flow patterns in the CoW vascular segment: ipsilateral A1 (n = 1) of the anterior cerebral artery (ACA), ipsilateral posterior communicating artery (PCoA) segment (n = 7), contralateral PCoA collateral (n = 4), bilateral PCoA (n = 2); (2) increased size or opening of the previous 'hypoplastic' segment of CoW: ipsilateral A1 of ACA (n = 1), contralateral PCoA (n = 2), bilateral PCoA (n = 1), and (3) biphasic alteration of the CoW: ceased ipsilateral PCoA segment and opening ipsilateral A1 of the ACA (n = 1), ceased ipsilateral PCoA and opening contralateral P1 of the posterior cerebral artery (n = 1). The plasticity of the flow patterns in the CoW are modulated by intracranial hemodynamics as shown by the AVM model. The calibers of CoW arterial segments are not a static feature. Willisian collateralization with recruitment of the CoW segment may cease, or hypoplastic segments may reopen after closing arteriovenous shunts of the AVM. (c) 2010 S. Karger AG, Basel.

Successful treatment of acquired uterine arterial venous malformation using N-butyl-2-cyanoacrylate under balloon occlusion

PubMed Central

Ogasawara, Go; Ishida, Kenichiro; Fujii, Kaoru; Yamane, Takuro; Nishimaki, Hiroshi; Matsunaga, Keiji; Inoue, Yusuke

2014-01-01

We present two cases of acquired uterine arterial venous malformation (AVM) which was diagnosed because of massive genital bleeding successfully treated with transcatheter arterial embolization (TAE), using N-butyl-2-cyanoacrylate (NBCA) under balloon occlusion. Balloon occlusion at the uterine artery was performed in both patients for diffuse distribution of NBCA in multiple feeding branches, as well as to the pseudoaneurysm, and for the prevention of NBCA reflux. In one of our patients, balloon occlusion of the draining vein was simultaneously performed to prevent NBCA migration through accompanying high-flow arteriovenous fistula (AVF). Doppler ultrasound at 6 months of both patients documented persistent complete occlusion of AVM. Complete and safe obliteration of acquired uterine AVM was accomplished using NBCA as embolic agent, under balloon occlusion at the communicating vessels of acquired uterine AVM. PMID:25346850

Automatic vehicle monitoring systems study. Report of phase O. Volume 2: Problem definition and derivation of AVM system selection techniques

NASA Technical Reports Server (NTRS)

1976-01-01

A set of planning guidelines is presented to help law enforcement agencies and vehicle fleet operators decide which automatic vehicle monitoring (AVM) system could best meet their performance requirements. Improvements in emergency response times and resultant cost benefits obtainable with various operational and planned AVM systems may be synthesized and simulated by means of special computer programs for model city parameters applicable to small, medium and large urban areas. Design characteristics of various AVM systems and the implementation requirements are illustrated and cost estimated for the vehicles, the fixed sites and the base equipments. Vehicle location accuracies for different RF links and polling intervals are analyzed. Actual applications and coverage data are tabulated for seven cities whose police departments actively cooperated in the study.

Transcatheter arterial embolization with ethylene vinyl alcohol copolymer (Onyx) for the treatment of hemorrhage due to uterine arteriovenous malformations.

PubMed

Barral, P-A; Saeed-Kilani, M; Tradi, F; Dabadie, A; Izaaryene, J; Soussan, J; Bartoli, J-M; Vidal, V

2017-05-01

The purpose of this study was to evaluate the effectiveness of ethylene vinyl alcohol copolymer (Onyx) as a single embolic agent for percutaneous arterial treatment of hemorrhage due to uterine arteriovenous malformations (AVMs). Twelve women (mean age, 33 years) with metrorrhagia due to uterine AVMs who were treated by percutaneous arterial embolization using Onyx as a single embolic agent were retrospectively included. The diagnosis of uterine AVM was suggested by pelvic ultrasound and/or magnetic resonance imaging findings and further confirmed by angiography. Clinical files and angiographic examinations were reviewed for angiographic findings, technical and clinical success, procedure complication and further pregnancies. Clinical success was defined by absence of metrorrhagia at 1 month following embolization. Sixteen arterial embolization procedures were performed. Angiographically, 6 women had high flow AVM and 6 had low flow AVM. The rate of technical and clinical success was 92% (11/12 patients). One woman with early repeat hemorrhage underwent two embolization procedures and further hysterectomy. No severe complications were observed after embolization. Three women (3/12; 25%) became pregnant following embolization including one full term pregnancy. In women with metrorrhagia due to AVM, arterial embolization with Onyx is effective and safe. Additional research is needed to confirm the possibility of future pregnancy after Onyx embolization. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Elaboration of a semi-automated algorithm for brain arteriovenous malformation segmentation: initial results.

PubMed

Clarençon, Frédéric; Maizeroi-Eugène, Franck; Bresson, Damien; Maingreaud, Flavien; Sourour, Nader; Couquet, Claude; Ayoub, David; Chiras, Jacques; Yardin, Catherine; Mounayer, Charbel

2015-02-01

The purpose of our study was to distinguish the different components of a brain arteriovenous malformation (bAVM) on 3D rotational angiography (3D-RA) using a semi-automated segmentation algorithm. Data from 3D-RA of 15 patients (8 males, 7 females; 14 supratentorial bAVMs, 1 infratentorial) were used to test the algorithm. Segmentation was performed in two steps: (1) nidus segmentation from propagation (vertical then horizontal) of tagging on the reference slice (i.e., the slice on which the nidus had the biggest surface); (2) contiguity propagation (based on density and variance) from tagging of arteries and veins distant from the nidus. Segmentation quality was evaluated by comparison with six frame/s DSA by two independent reviewers. Analysis of supraselective microcatheterisation was performed to dispel discrepancy. Mean duration for bAVM segmentation was 64 ± 26 min. Quality of segmentation was evaluated as good or fair in 93% of cases. Segmentation had better results than six frame/s DSA for the depiction of a focal ectasia on the main draining vein and for the evaluation of the venous drainage pattern. This segmentation algorithm is a promising tool that may help improve the understanding of bAVM angio-architecture, especially the venous drainage. • The segmentation algorithm allows for the distinction of the AVM's components • This algorithm helps to see the venous drainage of bAVMs more precisely • This algorithm may help to reduce the treatment-related complication rate.

A novel non-contrast-enhanced MRA using silent scan for evaluation of brain arteriovenous malformation: A case report and review of literature.

PubMed

Moon, Jin Il; Baek, Hye Jin; Ryu, Kyeong Hwa; Park, Hyun

2017-11-01

Brain arteriovenous malformations (AVMs) are congenital vascular abnormalities involving abnormal connections between arteries and veins. In clinical practice, imaging studies help evaluate feeding arteries, niduses, draining venous systems, and coexisting complications in patients with brain AVM. They also have an impact on decision-making regarding clinical management. We applied a novel non-contrast-enhanced MR angiography (MRA) technique, termed "silent MRA," for evaluating an incidental brain AVM. Here, we describe the clinical case with radiological review and highlight the technical background and clinical usefulness of silent MRA. A 60-year-old woman underwent neuroimaging study including MRA to evaluate intracranial cause of headache. The brain AVM, including its nidus and draining veins, was conspicuously delineated on silent MRA images; these findings correlated well with conventional angiographic findings. The patient did not receive interventional or surgical treatment. The patient is being followed up regularly at the outpatient department. The silent MRA can be a suitable imaging modality for repeated follow-up evaluation for not only brain AVMs but also various intracranial vascular diseases without the use of contrast materials.

Characterization of electrically-active defects in ultraviolet light-emitting diodes with laser-based failure analysis techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Mary A.; Tangyunyong, Paiboon; Cole, Edward I.

2016-01-14

Laser-based failure analysis techniques demonstrate the ability to quickly and non-intrusively screen deep ultraviolet light-emitting diodes (LEDs) for electrically-active defects. In particular, two laser-based techniques, light-induced voltage alteration and thermally-induced voltage alteration, generate applied voltage maps (AVMs) that provide information on electrically-active defect behavior including turn-on bias, density, and spatial location. Here, multiple commercial LEDs were examined and found to have dark defect signals in the AVM indicating a site of reduced resistance or leakage through the diode. The existence of the dark defect signals in the AVM correlates strongly with an increased forward-bias leakage current. This increased leakage ismore » not present in devices without AVM signals. Transmission electron microscopy analysis of a dark defect signal site revealed a dislocation cluster through the pn junction. The cluster included an open core dislocation. Even though LEDs with few dark AVM defect signals did not correlate strongly with power loss, direct association between increased open core dislocation densities and reduced LED device performance has been presented elsewhere [M. W. Moseley et al., J. Appl. Phys. 117, 095301 (2015)].« less

Characterization of electrically-active defects in ultraviolet light-emitting diodes with laser-based failure analysis techniques

DOE PAGES

Miller, Mary A.; Tangyunyong, Paiboon; Edward I. Cole, Jr.

2016-01-12

In this study, laser-based failure analysis techniques demonstrate the ability to quickly and non-intrusively screen deep ultraviolet light-emitting diodes(LEDs) for electrically-active defects. In particular, two laser-based techniques, light-induced voltage alteration and thermally-induced voltage alteration, generate applied voltage maps (AVMs) that provide information on electrically-active defect behavior including turn-on bias, density, and spatial location. Here, multiple commercial LEDs were examined and found to have dark defect signals in the AVM indicating a site of reduced resistance or leakage through the diode. The existence of the dark defect signals in the AVM correlates strongly with an increased forward-bias leakage current. This increasedmore » leakage is not present in devices without AVM signals. Transmission electron microscopyanalysis of a dark defect signal site revealed a dislocation cluster through the pn junction. The cluster included an open core dislocation. Even though LEDs with few dark AVM defect signals did not correlate strongly with power loss, direct association between increased open core dislocation densities and reduced LED device performance has been presented elsewhere [M. W. Moseley et al., J. Appl. Phys. 117, 095301 (2015)].« less

A Systematic Review of Acquired Uterine Arteriovenous Malformations: Pathophysiology, Diagnosis, and Transcatheter Treatment

PubMed Central

Yoon, Daniel J.; Jones, Megan; Taani, Jamal Al; Buhimschi, Catalin; Dowell, Joshua D.

2015-01-01

Objective An acquired uterine arteriovenous malformation (AVM) is a rare cause of vaginal bleeding and, although hysterectomy is the definitive therapy, transcatheter embolization (TCE) provides an alternative treatment option. This systematic review presents the indications, technique, and outcomes for transcatheter treatment of the acquired uterine AVMs. Study Design Literature databases were searched from 2003 to 2013 for eligible clinical studies, including the patient characteristics, procedural indication, results, complications, as well as descriptions on laterality and embolic agents utilized. Results A total of 40 studies were included comprising of 54 patients (average age of 33.4 years). TCE had a primary success rate with symptomatic control of 61% (31 patients) and secondary success rate of 91% after repeated embolization. When combined with medical therapy, symptom resolution was noted in 48 (85%) patients without more invasive surgical procedures. Conclusion Low-level evidence supports the role of TCE, including in the event of persistent bleeding following initial embolization, for the treatment of acquired uterine AVMs. The variety of embolic agents and laterality of approach delineate the importance of refining procedural protocols in the treatment of the acquired uterine AVM. Condensation A review on the management of patients with acquired uterine AVMs. PMID:26929872

Stereotactic radiosurgery for deep intracranial arteriovenous malformations, part 1: Brainstem arteriovenous malformations.

PubMed

Cohen-Inbar, Or; Ding, Dale; Chen, Ching-Jen; Sheehan, Jason P

2016-02-01

The management of brainstem arteriovenous malformations (AVM) are one of the greatest challenges encountered by neurosurgeons. Brainstem AVM have a higher risk of hemorrhage compared to AVM in other locations, and rupture of these lesions commonly results in devastating neurological morbidity and mortality. The potential morbidity associated with currently available treatment modalities further compounds the complexity of decision making for affected patients. Stereotactic radiosurgery (SRS) has an important role in the management of brainstem AVM. SRS offers acceptable obliteration rates with lower risks of hemorrhage occurring during the latency period. Complex nidal architecture requires a multi-disciplinary treatment approach. Nidi partly involving subpial/epipial regions of the dorsal midbrain or cerebellopontine angle should be considered for a combination of endovascular embolization, micro-surgical resection and SRS. Considering the fact that incompletely obliterated lesions (even when reduced in size) could still cause lethal hemorrhages, additional treatment, including repeat SRS and surgical resection should be considered when complete obliteration is not achieved by first SRS. Patients with brainstem AVM require continued clinical and radiological observation and follow-up after SRS, well after angiographic obliteration has been confirmed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vascular deficiency of Smad4 causes arteriovenous malformations: a mouse model of Hereditary Hemorrhagic Telangiectasia.

PubMed

Crist, Angela M; Lee, Amanda R; Patel, Nehal R; Westhoff, Dawn E; Meadows, Stryder M

2018-05-01

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder that leads to abnormal connections between arteries and veins termed arteriovenous malformations (AVM). Mutations in TGFβ pathway members ALK1, ENG and SMAD4 lead to HHT. However, a Smad4 mouse model of HHT does not currently exist. We aimed to create and characterize a Smad4 endothelial cell (EC)-specific, inducible knockout mouse (Smad4 f/f ;Cdh5-Cre ERT2 ) that could be used to study AVM development in HHT. We found that postnatal ablation of Smad4 caused various vascular defects, including the formation of distinct AVMs in the neonate retina. Our analyses demonstrated that increased EC proliferation and size, altered mural cell coverage and distorted artery-vein gene expression are associated with Smad4 deficiency in the vasculature. Furthermore, we show that depletion of Smad4 leads to decreased Vegfr2 expression, and concurrent loss of endothelial Smad4 and Vegfr2 in vivo leads to AVM enlargement. Our work provides a new model in which to study HHT-associated phenotypes and links the TGFβ and VEGF signaling pathways in AVM pathogenesis.

Molecular and cellular biology of cerebral arteriovenous malformations: a review of current concepts and future trends in treatment.

PubMed

Rangel-Castilla, Leonardo; Russin, Jonathan J; Martinez-Del-Campo, Eduardo; Soriano-Baron, Hector; Spetzler, Robert F; Nakaji, Peter

2014-09-01

Arteriovenous malformations (AVMs) are classically described as congenital static lesions. However, in addition to rupturing, AVMs can undergo growth, remodeling, and regression. These phenomena are directly related to cellular, molecular, and physiological processes. Understanding these relationships is essential to direct future diagnostic and therapeutic strategies. The authors performed a search of the contemporary literature to review current information regarding the molecular and cellular biology of AVMs and how this biology will impact their potential future management. A PubMed search was performed using the key words "genetic," "molecular," "brain," "cerebral," "arteriovenous," "malformation," "rupture," "management," "embolization," and "radiosurgery." Only English-language papers were considered. The reference lists of all papers selected for full-text assessment were reviewed. Current concepts in genetic polymorphisms, growth factors, angiopoietins, apoptosis, endothelial cells, pathophysiology, clinical syndromes, medical treatment (including tetracycline and microRNA-18a), radiation therapy, endovascular embolization, and surgical treatment as they apply to AVMs are discussed. Understanding the complex cellular biology, physiology, hemodynamics, and flow-related phenomena of AVMs is critical for defining and predicting their behavior, developing novel drug treatments, and improving endovascular and surgical therapies.

Unusual Association: Cerebral Arteriovenous Malformation and Chiari Type I Malformation.

PubMed

Ogul, Hayri; Kantarci, Mecit

2017-06-01

Cerebral arteriovenous malformation (AVM) is a common type of cerebral vascular malformation. The imaging findings are enlarged vessels, thrombosed sinuses, and hemorrhage or gliosis on adjacent brain parenchyma. Magnetic resonance (MR) imaging can be used safely for diagnosis. Chiari type I malformation is characterized by a caudal descent of the cerebellar tonsil. Coincidence of cerebral AVM and Chiari type I malformation is very rare. In this paper, the authors report MR imaging findings of a patient with coincidence of cerebral AVM and Chiari type I malformation.

Explicet: graphical user interface software for metadata-driven management, analysis and visualization of microbiome data.

PubMed

Robertson, Charles E; Harris, J Kirk; Wagner, Brandie D; Granger, David; Browne, Kathy; Tatem, Beth; Feazel, Leah M; Park, Kristin; Pace, Norman R; Frank, Daniel N

2013-12-01

Studies of the human microbiome, and microbial community ecology in general, have blossomed of late and are now a burgeoning source of exciting research findings. Along with the advent of next-generation sequencing platforms, which have dramatically increased the scope of microbiome-related projects, several high-performance sequence analysis pipelines (e.g. QIIME, MOTHUR, VAMPS) are now available to investigators for microbiome analysis. The subject of our manuscript, the graphical user interface-based Explicet software package, fills a previously unmet need for a robust, yet intuitive means of integrating the outputs of the software pipelines with user-specified metadata and then visualizing the combined data.

Active Vertex Model for cell-resolution description of epithelial tissue mechanics

PubMed Central

Barton, Daniel L.; Henkes, Silke

2017-01-01

We introduce an Active Vertex Model (AVM) for cell-resolution studies of the mechanics of confluent epithelial tissues consisting of tens of thousands of cells, with a level of detail inaccessible to similar methods. The AVM combines the Vertex Model for confluent epithelial tissues with active matter dynamics. This introduces a natural description of the cell motion and accounts for motion patterns observed on multiple scales. Furthermore, cell contacts are generated dynamically from positions of cell centres. This not only enables efficient numerical implementation, but provides a natural description of the T1 transition events responsible for local tissue rearrangements. The AVM also includes cell alignment, cell-specific mechanical properties, cell growth, division and apoptosis. In addition, the AVM introduces a flexible, dynamically changing boundary of the epithelial sheet allowing for studies of phenomena such as the fingering instability or wound healing. We illustrate these capabilities with a number of case studies. PMID:28665934

Generalized pixel profiling and comparative segmentation with application to arteriovenous malformation segmentation.

PubMed

Babin, D; Pižurica, A; Bellens, R; De Bock, J; Shang, Y; Goossens, B; Vansteenkiste, E; Philips, W

2012-07-01

Extraction of structural and geometric information from 3-D images of blood vessels is a well known and widely addressed segmentation problem. The segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, with a special application in diagnostics and surgery on arteriovenous malformations (AVM). However, the techniques addressing the problem of the AVM inner structure segmentation are rare. In this work we present a novel method of pixel profiling with the application to segmentation of the 3-D angiography AVM images. Our algorithm stands out in situations with low resolution images and high variability of pixel intensity. Another advantage of our method is that the parameters are set automatically, which yields little manual user intervention. The results on phantoms and real data demonstrate its effectiveness and potentials for fine delineation of AVM structure. Copyright © 2012 Elsevier B.V. All rights reserved.

Active Vertex Model for cell-resolution description of epithelial tissue mechanics.

PubMed

Barton, Daniel L; Henkes, Silke; Weijer, Cornelis J; Sknepnek, Rastko

2017-06-01

We introduce an Active Vertex Model (AVM) for cell-resolution studies of the mechanics of confluent epithelial tissues consisting of tens of thousands of cells, with a level of detail inaccessible to similar methods. The AVM combines the Vertex Model for confluent epithelial tissues with active matter dynamics. This introduces a natural description of the cell motion and accounts for motion patterns observed on multiple scales. Furthermore, cell contacts are generated dynamically from positions of cell centres. This not only enables efficient numerical implementation, but provides a natural description of the T1 transition events responsible for local tissue rearrangements. The AVM also includes cell alignment, cell-specific mechanical properties, cell growth, division and apoptosis. In addition, the AVM introduces a flexible, dynamically changing boundary of the epithelial sheet allowing for studies of phenomena such as the fingering instability or wound healing. We illustrate these capabilities with a number of case studies.

Moving diabetes management from clinic to community: development of a prototype based on automated voice messaging.

PubMed

Piette, J D

1997-01-01

The purpose of this study is twofold. First, it provides a review of the literature supporting the development of a new service to help patients with diabetes and their providers manage their care. This service, automated voice messaging (AVM) with nurse follow-up, allows for systematic and intensive patient monitoring and diabetes education as well as a means of focusing clinical resources where they are most needed. Second, it provides a description of a prototype AVM-based diabetes management service that has been developed as part of two ongoing, randomized, controlled trials to test the efficacy of AVM care for patients with Type 2 diabetes. Preliminary findings from implementing this service in two large public healthcare systems suggest that AVM-supported care is feasible, desirable by clinicians and patients with diabetes, and may identify serious health problems that otherwise would go unnoted through standard means of clinic-based patient care.

Curative embolization of pediatric intracranial arteriovenous malformations using Onyx: the role of new embolization techniques on patient outcomes.

PubMed

de Castro-Afonso, L H; Nakiri, G S; Oliveira, R S; Santos, M V; Santos, A C Dos; Machado, H R; Abud, D G

2016-06-01

Intracranial arteriovenous malformations (AVMs) are the most frequent cause of hemorrhagic strokes in the pediatric population. The study aim was to retrospectively assess the safety and efficacy of Onyx embolization with the intention to cure AVMs in a pediatric population. A retrospective analysis of all patients (<18 years) who underwent endovascular embolization using Onyx at our institution was conducted. The primary endpoint was the composite complete angiographic occlusion of AVM immediately after the last embolization session that had no procedure-related complication requiring emergency surgery. Secondary endpoints were angiographic occlusion rates, procedure-related complications, and clinical outcomes after treatment and at the 6-month follow-up Twenty-three patients (mean age, 11.7 years) underwent a total of 45 embolization sessions. The median Spetzler-Martin grade was 3 (range 1 to 4). The primary endpoint was achieved in 19 patients (82.6 %). Complete angiographic occlusion of the AVM was obtained in 21 patients (91.3 %) immediately after embolization and at the 6-month follow-up. Embolization-related complications were observed in three patients (13 %). None of the complications resulted in permanent functional disability or death. In two patients (8.7 %), the AVM could not be completely occluded by embolization alone and the patients were referred to radiosurgery and microsurgery, respectively. Onyx embolization of AVM in pediatric patients with the intention to cure resulted in high occlusion rates without increasing neurological disability or death. The development of new embolization techniques and devices seems to improve the safety of Onyx embolization.

Seizures after Onyx embolization for the treatment of cerebral arteriovenous malformation.

PubMed

de Los Reyes, K; Patel, A; Doshi, A; Egorova, N; Panov, F; Bederson, J B; Frontera, J A

2011-09-01

Onyx embolization of cerebral arteriovenous malformations (AVM) has become increasingly common. We explored the risk of seizures after Onyx use.A retrospective review was conducted of 20 patients with supratentorial brain arteriovenous malformation (AVM) who received Onyx embolization between 2006 and 2009. Baseline demographics, clinical history, seizure history, AVM characteristics and treatment were compared between those who developed post-onyx seizure and those who did not. MRIs were reviewed for edema following Onyx treatment.Of 20 patients who underwent Onyx embolization, the initial AVM presentation was hemorrhage in 40% (N=8). The median number of embolizations was two (range 1-4) and the median final obliteration amount was 90% (range 50-100%). A history of seizure was present in 50% (N=10) of patients pre-embolization and 12 (60%) patients received seizure medications (treatment or prophylaxis) prior to embolization. Seizur post-Onyx embolization occurred in 45% (N=9). The median time to seizur post-Onyx was seven days (range 0.3-210). Four patients (20%) with seizures post-Onyx had no seizure history. Two of these patients (10%) had no other identifiable cause for seizure other than recent Onyx embolization. Seizures in these two patients occurred within 24 hours of Onyx administration. Among patients with post-Onyx seizures, there was a trend toward larger AVM size (P=0.091) and lower percent obliteration (P=0.062). Peri-AVM edema was present in 75% of MRIs performed within one month of Onyx treatment and may represent a possible etiology for seizures.New onset seizures post-Onyx embolization are not uncommon. Further study of seizure prevention is warranted.

Evaluation of Angioarchitectural Features of Unruptured Brain Arteriovenous Malformation by Susceptibility Weighted Image (SWI).

PubMed

Wu, Chun-Xue; Ma, Li; Chen, Xu-Zhu; Chen, Xiao-Lin; Chen, Yu; Zhao, Yuan-Li; Hess, Christopher; Kim, Helen; Jin, Heng-Wei; Ma, Jun

2018-05-30

A precise assessment of angioarchitectural characteristics using non-invasive imaging is helpful for serial follow-up and weighting risk of natural history in uruptured brain arteriovenous malformation (bAVM). This study aimed to test the hypothesis that susceptibility weighted image (SWI) would provide an accurate evaluation of angioarchitectural features of unruptured bAVM.. A total of 81 consecutive patients with unruptured bAVM were examined. Image quality of SWI for the assessment of bAVM angioarchitectural features were determined by a five-point scale. The accuracy of SWI for detection of angioarchitectural features was evaluated using DSA as a standard reference. And further compared among unruptured bAVMs with or without silent intralesional microhemorrhage on SWI to examine the potential confounding effect of microhemorrhage on image analysis. All lesions were identified on SWI. Image quality of SWI was judged to be at least adequate for diagnosis (range, 3-5) in all patients by both readers. Using DSA as reference standard, the area under receiver operating curve (AUC) of detection of deep or posterior fossa location, exclusively deep venous drainage, venous ectasia, venous varices and the presence of associated aneurysm on SWI was 1, 0.93, 0.94, 0.95, and 0.83, respectively. Silent intralesional microhemorrhage were detected in 39 patients (48.15%) on SWI and no significant difference (P > 0.05) was found in angioarchitectural features between cases with and without silent microhemorrhage. SWI might be a non-invasive alternative technique for angiogram in the angioarchitectural assessment of unruptured bAVM. Copyright © 2018. Published by Elsevier Inc.

Utilization of Cone-Beam Computed Tomographic Angiography in Planning for Gamma Knife Radiosurgery of Arteriovenous Malformations: A Case Series and Early Report

PubMed Central

Safain, Mina G.; Rahal, Jason P.; Raval, Ami; Rivard, Mark J.; Mignano, John; Wu, Julian; Malek, Adel M.

2014-01-01

Background The effectiveness of Gamma Knife radiosurgery (GKR) for cerebral arteriovenous malformations (AVM) is predicated on inclusion of the entire nidus while excluding normal tissue. As such, GKR may be limited by the resolution and accuracy of the imaging modality used in targeting. Objective We present the first case series to demonstrate the feasibility of utilizing ultra-high-resolution C-arm cone beam computed tomography angiography (CBCT-A) in AVM targeting. Methods From June 2009 to June 2013, CBCT-A was utilized for targeting of all patients with AVMs treated with GKR at our institution. Patients underwent Leksell stereotactic head frame placement followed by catheter-based biplane 2-D digital subtraction angiography (DSA), 3-D rotational angiography (3DRA), as well as CBCT-A. The CBCT-A dataset was used for stereotactic planning for GKR. Patients were followed up at 1, 3, 6, and 12 months, and then annually thereafter. Results CBCT-A-based targeting was used in twenty-two consecutive patients. CBCT-A provided detailed spatial resolution and sensitivity of nidal angioarchitecture enabling treatment. The average radiation dose to the margin of the AVM nidus corresponding to the 50% percent isodose line was 15.6 Gy. No patient had treatment-associated hemorrhage. At early follow-up (mean=16 months), 84% of patients had a decreasing or obliterated AVM nidus. Conclusion CBCT-A-guided radiosurgery is feasible and useful because it provides sufficient detailed resolution and sensitivity for imaging brain AVMs. PMID:24584136

Spontaneous thrombosis of the main draining vein revealing an unruptured brain arteriovenous malformation

PubMed Central

Cao, Catherine; Sourour, Nader; Reina, Vincent; Nouet, Aurélien; Di Maria, Federico; Chiras, Jacques; Cornu, Philippe

2015-01-01

Haemorrhage is the most frequent revealing condition of brain arteriovenous malformations (bAVMs). We report a rare case of unruptured parietal bAVM revealed by spontaneous thrombosis of the main draining vein, responsible for a focal neurological deficit. The bAVM was embolized in emergency conditions; complete regression of the neurological symptoms was observed within five days after the embolization. Potential mechanisms of such spontaneous thrombosis of the bAVM’s main drainage pathway as well as an exhaustive review of the literature concerning this rare revealing condition are presented and discussed. PMID:25964440

Interplay between VEGF and Nrf2 regulates angiogenesis due to intracranial venous hypertension.

PubMed

Li, Liwen; Pan, Hao; Wang, Handong; Li, Xiang; Bu, Xiaomin; Wang, Qiang; Gao, Yongyue; Wen, Guodao; Zhou, Yali; Cong, Zixiang; Yang, Youqing; Tang, Chao; Liu, Zhengwei

2016-11-21

Venous hypertension(VH) plays an important role in the pathogenesis of cerebral arteriovenous malformations (AVMs) and is closely associated with the HIF-1α/VEGF signaling pathway. Nuclear factor erythroid 2-related factor 2(Nrf2) significantly influences angiogenesis; however, the interplay between Nrf2 and VEGF under VH in brain AVMs remains unclear. Therefore, our study aimed to investigate the interplay between Nrf2 and VEGF due to VH in brain AVMs. Immunohistochemistry indicated that Nrf2 and VEGF were highly expressed in human brain AVM tissues. In vivo, we established a VH model in both wild-type (WT) and siRNA-mediated Nrf2 knockdown rats. VH significantly increased the expression of Nrf2 and VEGF. Loss of Nrf2 markedly inhibited the upregulation of VEGF, as determined by Western blot analysis and qRT-PCR. In vitro, primary brain microvascular endothelial cells (BMECs) were isolated from WT and Nrf2 -/- mice, and a VEGF-Nrf2 positive feed-back loop was observed in BMECs. By trans well assay and angiogenesis assay, Nrf2 knockout significantly inhibited the migration and vascular tube formation of BMECs. These findings suggest that the interplay between Nrf2 and VEGF can contribute to VH-induced angiogenesis in brain AVMs pathogenesis.

Transarterial Coil-Augmented Onyx Embolization for Brain Arteriovenous Malformation

PubMed Central

Gao, Xu; Liang, Guobiao; Li, Zhiqing; Wang, Xiaogang; Yu, Chunyong; Cao, Peng; Chen, Jun; Li, Jingyuan

2014-01-01

Summary Onyx has been widely adopted for the treatment of arteriovenous malformations (AVMs). However, its control demands operators accumulate a considerable learning curve. We describe our initial experience using a novel injection method for the embolization of AVMs. We retrospectively reviewed the data of all 22 patients with brain AVMs (12 men, 10 women; age range, 12-68 years; mean age, 43.2 years) treated by the transarterial coil-augmented Onyx injection technique. The size of the AVMs ranged from 25 mm to 70 mm (average 35.6 mm). The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. In every case, endovascular treatment (EVT) was completed. A total of 31 sessions were performed, with a mean injection volume of 6.1 mL (range, 1.5-16.0 mL). An average of 96.7% (range 85%-100%) estimated size reduction was achieved, and 18 AVMs could be completely excluded by EVT alone. The results remained stable on follow-up angiograms. A procedural complication occurred in one patient, with permanent mild neurologic deficit. Our preliminary series demonstrated that the coil-augmented Onyx injection technique is a valuable adjunct achieving excellent nidal penetration and improving the safety of the procedure. PMID:24556304

Introduction to tractography-guided navigation: using 3-tesla magnetic resonance tractography in surgery for cerebral arteriovenous malformations.

PubMed

Kikuta, K; Takagi, Y; Nozaki, K; Hashimoto, N

2008-01-01

To examine the effectiveness of magnetic resonance (MR) tractography in surgery for cerebral arteriovenous malformations (AVMs). A preoperative evaluation of major neural tracts around the nidus was carried out with 3-tesla (3 T) MR tractography in 25 consecutive patients with cerebral AVMs. The patients were 12 men and 13 women ranging in age from 4 to 60 years of age (mean age: 31.2 +/- 14.1 years). Twelve presented with hemorrhage. Images were obtained with T2-weighted turbo spin echo sequences, axial T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) sequences, three-dimensional time-of-flight MR angiography (3D TOF MRA), and thin-section diffusion-tensor imaging (DTI). The AVMs were obliterated in 22 of the 25 patients. A postoperative study of the MR tractography was carried out in 24 patients. In 21 patients, tracts were preserved and no postoperative neurological worsening was observed. Disruption of the tracts was found in 3 patients, and postoperative worsening was observed in 2 patients. However, no deterioration occurred in 1 patient with cerebellar AVM. Notwithstanding the limitations of this method, MR tractography can be considered useful for confirming the integrity of deviated tracts, for localizing deviated tracts, and for evaluating surgical risk, especially in cases of non-hemorrhagic AVM.

Metadata improvements driving new tools and services at a NASA data center

NASA Astrophysics Data System (ADS)

Moroni, D. F.; Hausman, J.; Foti, G.; Armstrong, E. M.

2011-12-01

The NASA Physical Oceanography DAAC (PO.DAAC) is responsible for distributing and maintaining satellite derived oceanographic data from a number of NASA and non-NASA missions for the physical disciplines of ocean winds, sea surface temperature, ocean topography and gravity. Currently its holdings consist of over 600 datasets with a data archive in excess of 200 Terrabytes. The PO.DAAC has recently embarked on a metadata quality and completeness project to migrate, update and improve metadata records for over 300 public datasets. An interactive database management tool has been developed to allow data scientists to enter, update and maintain metadata records. This tool communicates directly with PO.DAAC's Data Management and Archiving System (DMAS), which serves as the new archival and distribution backbone as well as a permanent repository of dataset and granule-level metadata. Although we will briefly discuss the tool, more important ramifications are the ability to now expose, propagate and leverage the metadata in a number of ways. First, the metadata are exposed directly through a faceted and free text search interface directly from drupal-based PO.DAAC web pages allowing for quick browsing and data discovery especially by "drilling" through the various facet levels that organize datasets by time/space resolution, processing level, sensor, measurement type etc. Furthermore, the metadata can now be exposed through web services to produce metadata records in a number of different formats such as FGDC and ISO 19115, or potentially propagated to visualization and subsetting tools, and other discovery interfaces. The fundamental concept is that the metadata forms the essential bridge between the user, and the tool or discovery mechanism for a broad range of ocean earth science data records.

Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations.

PubMed

Zhao, Zhenjun; Johnson, Michael S; Chen, Biyi; Grace, Michael; Ukath, Jaysree; Lee, Vivienne S; McRobb, Lucinda S; Sedger, Lisa M; Stoodley, Marcus A

2016-06-01

OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation causes remarkable cellular changes in endothelial cells. Significant PS externalization is induced by radiation at doses of 15 Gy or higher, concomitant with a block in the cell cycle. Radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for AVM treatment.

Obliteration dynamics in cerebral arteriovenous malformations after cyberknife radiosurgery: quantification with sequential nidus volumetry and 3-tesla 3-dimensional time-of-flight magnetic resonance angiography.

PubMed

Wowra, Berndt; Muacevic, Alexander; Tonn, Jörg-Christian; Schoenberg, Stefan O; Reiser, Maximilian; Herrmann, Karin A

2009-02-01

To investigate the time-dependent obliteration of cerebral arteriovenous malformations (cAVM) after CyberKnife radiosurgery (CKRS) (Accuray, Inc., Sunnyvale, CA) by means of sequential 3-T, 3-dimensional (3D), time-of-flight (TOF) magnetic resonance angiography (MRA), and volumetry of the arteriovenous malformation (AVM) nidus. In this prospective study, 3D TOF MRA was performed on 20 patients with cAVMs treated by single-fraction CKRS. Three-dimensional TOF MRA was performed on a 3-T, 32-channel magnetic resonance scanner (Magnetom TIM Trio; Siemens Medical Solutions, Erlangen, Germany) with isotropic voxel size at a spatial resolution of 0.6 x 0.6 x 0.6 mm3. The time-dependent relative decay of the transnidal blood flow evidenced by 3D TOF MRA was referred to as "obliteration dynamics." Volumetry of the nidus size was performed with OsiriX imaging software (OsiriX Foundation, Geneva, Switzerland). All patients had 3 to 4 follow-up examinations at 3- to 6-month intervals over a minimum follow-up period of 9 months. Subtotal obliteration was determined if the residual nidus volume was 5% or less of the initial nidus volume. Stata/IC software (Version 10.0; Stata Corp., College Station, TX) was used for statistical analysis and to identify potential factors of AVM obliteration. Regarding their clinical status, case history, and pretreatments, the participants of this study represent difficult-to-treat cAVM patients. The median nidus volume was 1.8 mL (range, 0.4-12.5 mL); the median minimum dose prescribed to the nidus was 22 Gy (range, 16-24 Gy) delivered to the 67% isodose line (range, 55-80%). CKRS was well tolerated, with complications in 2 patients. No further hemorrhages occurred after RS, except 1 small and clinically inapparent incident. The median follow-up period after RS was 25.0 months (range, 11.7-36.8 months). After RS, a statistically significant obliteration was observed in all patients. However, the obliteration dynamics of the cAVMs showed a pronounced variability, with 2 types of post-therapeutic behavior identified. cAVMs of Group A showed a faster reduction of transnidal blood flow than cAVMs in Group B. The median time to subtotal obliteration was 23.8 months for all patients, 11.6 months for patients in Group A, and 27.8 months for patients in Group B (P = 0.05). Logistic regression analysis revealed dose homogeneity and the circumscribed isodose to be the only variables (P < 0.01) associated with the obliteration dynamics in this study. The cumulative complete angiographic obliteration rate was 67% (95% confidence interval, 32-95%) 2 years after RS. The use of sequential 3D TOF MRA at 3 T and nidus volumetry enables a noninvasive quantitative assessment of the dynamic obliteration process induced by CKRS in cAVMs. This method may be helpful to identify factors related to AVM obliteration after RS when larger patient cohorts become available.

47 CFR 90.363 - Grandfathering provisions for existing AVM licensees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Grandfathering provisions for existing AVM licensees. 90.363 Section 90.363 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Intelligent Transportation Systems Radio Service...

Atmospheric Radiation Measurement's Data Management Facility captures metadata and uses visualization tools to assist in routine data management.

NASA Astrophysics Data System (ADS)

Keck, N. N.; Macduff, M.; Martin, T.

2017-12-01

The Atmospheric Radiation Measurement's (ARM) Data Management Facility (DMF) plays a critical support role in processing and curating data generated by the Department of Energy's ARM Program. Data are collected near real time from hundreds of observational instruments spread out all over the globe. Data are then ingested hourly to provide time series data in NetCDF (network Common Data Format) and includes standardized metadata. Based on automated processes and a variety of user reviews the data may need to be reprocessed. Final data sets are then stored and accessed by users through the ARM Archive. Over the course of 20 years, a suite of data visualization tools have been developed to facilitate the operational processes to manage and maintain the more than 18,000 real time events, that move 1.3 TB of data each day through the various stages of the DMF's data system. This poster will present the resources and methodology used to capture metadata and the tools that assist in routine data management and discoverability.

BIO::Phylo-phyloinformatic analysis using perl.

PubMed

Vos, Rutger A; Caravas, Jason; Hartmann, Klaas; Jensen, Mark A; Miller, Chase

2011-02-27

Phyloinformatic analyses involve large amounts of data and metadata of complex structure. Collecting, processing, analyzing, visualizing and summarizing these data and metadata should be done in steps that can be automated and reproduced. This requires flexible, modular toolkits that can represent, manipulate and persist phylogenetic data and metadata as objects with programmable interfaces. This paper presents Bio::Phylo, a Perl5 toolkit for phyloinformatic analysis. It implements classes and methods that are compatible with the well-known BioPerl toolkit, but is independent from it (making it easy to install) and features a richer API and a data model that is better able to manage the complex relationships between different fundamental data and metadata objects in phylogenetics. It supports commonly used file formats for phylogenetic data including the novel NeXML standard, which allows rich annotations of phylogenetic data to be stored and shared. Bio::Phylo can interact with BioPerl, thereby giving access to the file formats that BioPerl supports. Many methods for data simulation, transformation and manipulation, the analysis of tree shape, and tree visualization are provided. Bio::Phylo is composed of 59 richly documented Perl5 modules. It has been deployed successfully on a variety of computer architectures (including various Linux distributions, Mac OS X versions, Windows, Cygwin and UNIX-like systems). It is available as open source (GPL) software from http://search.cpan.org/dist/Bio-Phylo.

BIO::Phylo-phyloinformatic analysis using perl

PubMed Central

2011-01-01

Background Phyloinformatic analyses involve large amounts of data and metadata of complex structure. Collecting, processing, analyzing, visualizing and summarizing these data and metadata should be done in steps that can be automated and reproduced. This requires flexible, modular toolkits that can represent, manipulate and persist phylogenetic data and metadata as objects with programmable interfaces. Results This paper presents Bio::Phylo, a Perl5 toolkit for phyloinformatic analysis. It implements classes and methods that are compatible with the well-known BioPerl toolkit, but is independent from it (making it easy to install) and features a richer API and a data model that is better able to manage the complex relationships between different fundamental data and metadata objects in phylogenetics. It supports commonly used file formats for phylogenetic data including the novel NeXML standard, which allows rich annotations of phylogenetic data to be stored and shared. Bio::Phylo can interact with BioPerl, thereby giving access to the file formats that BioPerl supports. Many methods for data simulation, transformation and manipulation, the analysis of tree shape, and tree visualization are provided. Conclusions Bio::Phylo is composed of 59 richly documented Perl5 modules. It has been deployed successfully on a variety of computer architectures (including various Linux distributions, Mac OS X versions, Windows, Cygwin and UNIX-like systems). It is available as open source (GPL) software from http://search.cpan.org/dist/Bio-Phylo PMID:21352572

Interest of HYPR flow dynamic MRA for characterization of cerebral arteriovenous malformations: comparison with TRICKS MRA and catheter DSA.

PubMed

Dautry, Raphaël; Edjlali, Myriam; Roca, Pauline; Rabrait, Cécile; Wu, Yijing; Johnson, Kevin; Wieben, Olivier; Trystram, Denis; Rodriguez-Régent, Christine; Alshareef, Fawaz; Turski, Patrick; Meder, Jean-François; Naggara, Olivier; Oppenheim, Catherine

2015-11-01

HYPR flow is a 3D dynamic contrast-enhanced MRA technique providing isotropic sub-millimetre resolution with half-second temporal resolution. We compared HYPR flow and time-resolved imaging of contrast kinetics (TRICKS) MRA for the characterization of cerebral arteriovenous malformations (cAVMs), using catheter DSA as reference. Twenty-two patients underwent HYPR flow and TRICKS MRA within 15 days of DSA. HYPR flow and TRICKS datasets were reviewed separately by two readers for image quality, Spetzler-Martin grade, venous ectasia, and deep venous drainage. Image quality was better for HYPR flow than for TRICKS (narrower full width at half maximum; larger arterial diagnostic window; greater number of arterial frames, P ≤ 0.05). Using HYPR flow, inter-reader agreement was excellent for all cAVM characteristics. The agreement with DSA for the overall Spetzler-Martin grade was excellent for HYPR flow (ICC = 0.96 and 0.98, depending on the reader) and TRICKS (ICC = 0.82 and 0.95). In comparison to TRICKS, HYPR flow showed higher concordance with DSA for the identification of venous ectasia and deep venous drainage. Owing to an excellent agreement with DSA with respect to depiction of the vascular architecture of cAVMs, HYPR flow could be useful for the non-invasive characterization of cAVMs. • Dynamic MRA is used for cerebral AVM depiction and follow-up • HYPR flow is a new, highly-resolved dynamic MRA sequence • HYPR flow provides whole brain coverage • HYPR flow provides excellent agreement with the Spetzler-Martin grade • Compared to TRICKS MRA, HYPR flow improves cerebral AVM characterization.

Gamma knife surgery for brainstem arteriovenous malformations.

PubMed

Yen, Chun-Po; Steiner, Ladislau

2011-01-01

To evaluate the long-term imaging and clinical outcomes of patients with brainstem arteriovenous malformations (AVMs) treated with Gamma Knife surgery (GKS). The study included 85 patients with brainstem AVMs undergoing GKS during the period 1989-2007. The locations of the nidi were the midbrain in 42 patients, pons in 31 patients, and medulla oblongata in 12 patients. The volume of the nidi ranged from 0.1-8.9 mL (median 1.4 mL, mean 1.9 mL), and the prescription dose ranged from 5-32 Gy (median 20 Gy, mean 19.9 Gy). After the initial Gamma procedure, 18 patients had repeat GKS for AVM residuals that were still patent. Two patients had a third GKS 7 years and 16 years after a failed repeat GKS. Clinical follow-up ranged from 24-252 months with a mean of 100 months (median 102 months) after the initial GKS. GKS yielded a total angiographic obliteration in 50 (58.8%) patients and subtotal obliteration in 4 (4.7%) patients. In 22 (25.9%) patients, the AVMs remained patent. In 9 patients (10.6%), no flow voids were observed on magnetic resonance imaging (MRI), but angiographic confirmation was unavailable. A small nidus volume and a high prescription dose were significantly associated with increased AVM obliteration rate. Radiation-induced changes developed in 34 patients (40%); 24 were asymptomatic, 1 patient had only headache, and 9 patients developed neurologic deficits. One patient developed a large cyst 6 years after GKS. Given the poor surgical outcome of brainstem AVMs, the results of 59% nidus obliteration and 6% permanent neurologic deficits make GKS a reasonable management of these difficult lesions. Copyright © 2011 Elsevier Inc. All rights reserved.

Role of time-resolved-CTA in intracranial arteriovenous malformation evaluation at 128-slice CT in comparison with digital subtraction angiography.

PubMed

Singh, Rupinder; Gupta, Vivek; Ahuja, Chirag; Kumar, Ajay; Mukherjee, Kanchan K; Khandelwal, Niranjan

2018-06-01

Introduction The present study aimed to evaluate the accuracy of time-resolved-computed tomographic angiography (TR-CTA) on a 128-slice CT scanner vis-à-vis cerebral digital subtraction angiography (DSA) in defining the morphological and haemodynamic characteristics of cerebral arteriovenous malformation (AVM). Methods Twenty-one patients (age range 10-46, mean 24.8 years) with clinical suspicion of AVM and three patients (age range 23-35, mean 24.3 years) with diagnosed AVM who were on follow-up underwent DSA and TR-CTA, on average 1.5 days apart. Three independent neuroradiologists analysed both studies in a blinded fashion based on the following parameters: AVM location, arterial feeder territories, venous drainage pattern, nidus flow characteristics, venous outflow obstruction, arterial feeder enlargement, external carotid artery feeder, location of aneurysm if any, leptomeningeal and transdural recruitment, neoangiogenesis, and pseudophlebitic pattern. Results The TR-CTA correctly demonstrated AVM in all 21 positive cases. It concordantly detected location (21/21), venous drainage pattern (21/21), nidus flow characteristics (21/21), and the venous outflow obstruction (9/9). However, discordance was seen in the demonstration of the arterial feeder (2/45) ( p = 0.49), arterial enlargement (13/17) ( p = 0.103), external carotid artery feeder (0/1), aneurysmal location (3/5) ( p = 0.40), leptomeningeal recruitment (1/3) ( p = 0.40), neoangiogenesis (0/4) ( p = 0.028) and in the pseudophlebitic pattern (2/5) ( p = 0.167) demonstration. Conclusions The results suggest that TR-CTA can provide the important features of cerebral AVM which are required in patient management.

Seizures after Onyx Embolization for the Treatment of Cerebral Arteriovenous Malformation

PubMed Central

de los Reyes, K.; Patel, A.; Doshi, A.; Egorova, N.; Panov, F.; Bederson, J.B.; Frontera, J.A.

2011-01-01

Summary Onyx embolization of cerebral arteriovenous malformations (AVM) has become increasingly common. We explored the risk of seizures after Onyx use. A retrospective review was conducted of 20 patients with supratentorial brain arteriovenous malformation (AVM) who received Onyx embolization between 2006 and 2009. Baseline demographics, clinical history, seizure history, AVM characteristics and treatment were compared between those who developed post-onyx seizure and those who did not. MRIs were reviewed for edema following Onyx treatment. Of 20 patients who underwent Onyx embolization, the initial AVM presentation was hemorrhage in 40% (N=8). The median number of embolizations was two (range 1-4) and the median final obliteration amount was 90% (range 50-100%). A history of seizure was present in 50% (N=10) of patients pre-embolization and 12 (60%) patients received seizure medications (treatment or prophylaxis) prior to embolization. Seizur post-Onyx embolization occurred in 45% (N=9). The median time to seizur post-Onyx was seven days (range 0.3-210). Four patients (20%) with seizures post-Onyx had no seizure history. Two of these patients (10%) had no other identifiable cause for seizure other than recent Onyx embolization. Seizures in these two patients occurred within 24 hours of Onyx administration. Among patients with post-Onyx seizures, there was a trend toward larger AVM size (P=0.091) and lower percent obliteration (P=0.062). Peri-AVM edema was present in 75% of MRIs performed within one month of Onyx treatment and may represent a possible etiology for seizures. New onset seizures post-Onyx embolization are not uncommon. Further study of seizure prevention is warranted. PMID:22005695

Angioarchitectural features of brain arteriovenous malformations associated with seizures: a single center retrospective series.

PubMed

Sturiale, C L; Rigante, L; Puca, A; Di Lella, G; Albanese, A; Marchese, E; Di Rocco, C; Maira, G; Colicchio, G

2013-05-01

Epileptic seizures account for 24-40% of all clinical onsets in patients with brain arteriovenous malformations (AVMs). We retrospectively reviewed the angioarchitectural features of AVMs associated with seizures in 168 patients admitted to our Department from 1997 to 2012. Patients were dichotomized according to demographic characteristics, type of treatment, bleeding occurrence, and morphological and topographic features. Clinical status at admission and discharge was also recorded. The association of each one of these variables with seizures occurrence was statistically tested. Continuous variables and outcome were compared with Student's t-test, whereas categorical ones were compared using Fisher's exact test. The independent contribution of some seizures predictors was assessed with a logistic regression model. Associations were considered significant for P < 0.05. About 29% patients showed seizures and 47% bleeding. No significant difference in age and sex was observed between patients with and without seizures. AVMs > 4 cm (P = 0.001) and those fed by dilated arterial feeders (P = 0.02) were associated with increased risk of seizures. A higher risk of seizures occurrence was also observed in cortical AVMs compared with deeper ones (75.5% vs. 55.4%; P = 0.01), and in AVMs fed by middle and posterior cerebral arteries branches compared with the other vessels (81.6% vs. 45.3%; P < 0.001 and 48.9% vs. 23.5%; P = 0.002, respectively). No lobar predisposition was observed. A nidus > 4 cm also appeared as an independent risk factor of seizures occurrence (OR 2.82; 95% CI, 1.26-6.31; P = 0.009) at logistic regression analysis. AVM morphology, especially nidus dimension, appeared to more significantly influence seizures occurrence than their topography. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Angiotensin receptor blockade: a novel approach for symptomatic radiation necrosis after stereotactic radiosurgery

PubMed Central

Okwan-Duodu, Derick; Switchenko, Jeffrey M.; Press, Robert H.; Jhaveri, Jaymin; Buchwald, Zachary S.; Zhong, Jim; Chapman, Bhavana V.; Bindra, Ranjit S.; Contessa, Joseph N.; Park, Henry S.; Yu, James B.; Decker, Roy H.; Olson, Jeffrey J.; Oyesiku, Nelson M.; Abrams, Ross A.; Shu, Hui-Kuo G.; Curran, Walter J.; Crocker, Ian R.

2018-01-01

Preclinical evidence suggests angiotensin blockade therapy (ABT) decreases late radiation toxicities. This study aims to investigate the association between ABT and symptomatic radiation necrosis (SRN) following stereotactic radiosurgery (SRS). Resected brain metastases (rBM) and arteriovenous malformation (AVM) patients treated with SRS from 2002 to 2015 were identified. Patients in the ABT cohort were on therapy during SRS and at 1-month follow up. Kaplan Meier method and cumulative incidence model were used to analyze overall survival (OS) and intracranial outcomes. 228 consecutive patients were treated with SRS: 111 with rBM and 117 with AVM. Overall, 51 (22.4%) patients were in the ABT group: 32 (28.8%) in the rBM and 19 (16.2%) in AVM cohorts. Baseline characteristics were similar, except for higher Graded Prognostic Analysis (3–4) in the rBM (ABT: 25.0% vs. non-ABT: 49.0%, p = 0.033) and median age in the AVM (ABT: 51.4 vs. non-ABT: 35.4, p < 0.001) cohorts. In both populations, OS and intracranial efficacy (rBM—local control; AVM—obliteration rates) were statistically similar between the cohorts. ABT was associated with lower 1-year SRN rates in both populations: rBM, 3.1 versus 25.3% (p = 0.003); AVM, 6.7 vs. 14.6% (p = 0.063). On multivariate analysis, ABT was a significant predictive factor for rBM (HR: 0.17; 95% CI 0.03–0.88, p = 0.035), but did not reach statistical significance for AVM (HR: 0.36; 95% CI 0.09–1.52, p = 0.165). ABT use appears to be associated with a reduced risk of SRN following SRS, without detriment to OS or intracranial efficacy. A prospective trial to validate these findings is warranted. PMID:29124649

In vivo imaging of endothelial cell adhesion molecule expression after radiosurgery in an animal model of arteriovenous malformation.

PubMed

Raoufi-Rad, Newsha; McRobb, Lucinda S; Lee, Vivienne S; Bervini, David; Grace, Michael; Ukath, Jaysree; Mchattan, Joshua; Sreenivasan, Varun K A; Duong, T T Hong; Zhao, Zhenjun; Stoodley, Marcus A

2017-01-01

Focussed radiosurgery may provide a means of inducing molecular changes on the luminal surface of diseased endothelium to allow targeted delivery of novel therapeutic compounds. We investigated the potential of ionizing radiation to induce surface expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) on endothelial cells (EC) in vitro and in vivo, to assess their suitability as vascular targets in irradiated arteriovenous malformations (AVMs). Cultured brain microvascular EC were irradiated by linear accelerator at single doses of 0, 5, 15 or 25 Gy and expression of ICAM-1 and VCAM-1 measured by qRT-PCR, Western, ELISA and immunocytochemistry. In vivo, near-infrared (NIR) fluorescence optical imaging using Xenolight 750-conjugated ICAM-1 or VCAM-1 antibodies examined luminal biodistribution over 84 days in a rat AVM model after Gamma Knife surgery at a single 15 Gy dose. ICAM-1 and VCAM-1 were minimally expressed on untreated EC in vitro. Doses of 15 and 25 Gy stimulated expression equally; 5 Gy was not different from the unirradiated. In vivo, normal vessels did not bind or retain the fluorescent probes, however binding was significant in AVM vessels. No additive increases in probe binding were found in response to radiosurgery at a dose of 15 Gy. In summary, radiation induces adhesion molecule expression in vitro but elevated baseline levels in AVM vessels precludes further induction in vivo. These molecules may be suitable targets in irradiated vessels without hemodynamic derangement, but not AVMs. These findings demonstrate the importance of using flow-modulated, pre-clinical animal models for validating candidate proteins for vascular targeting in irradiated AVMs.

Assessment of craniospinal arteriovenous malformations at 3T with highly temporally and highly spatially resolved contrast-enhanced MR angiography.

PubMed

Saleh, R S; Lohan, D G; Villablanca, J P; Duckwiler, G; Kee, S T; Finn, J P

2008-05-01

Patients with arteriovenous malformation (AVM) are known to have an elevated risk of complications with conventional catheter angiography (CCA) but nonetheless require monitoring of hemodynamics. Thus, we aimed to evaluate both anatomy and hemodynamics in patients with AVM noninvasively by using contrast-enhanced MR angiography (CE-MRA) at 3T and to compare the results with CCA. Institutional review board approval and informed consent were obtained for this Health Insurance Portability and Accountability Act-compliant study. Twenty control subjects without vascular malformation (6 men, 18-70 years of age) and 10 patients with AVMs (6 men, 20-74 years of age) underwent supra-aortic time-resolved and high-spatial-resolution CE-MRA at 3T. Large-field-of-view coronal acquisitions extending from the root of the aorta to the cranial vertex were obtained for both MRA techniques. Image quality was assessed by 2 specialized radiologists by using a 4-point scale. AVM characteristics and nidus size were evaluated by using both CE-MRA and CCA in all patients. In patients, 96.6% (319/330) of arterial segments on high-spatial-resolution MRA and 87.7% (272/310) of arterial segments on time-resolved MRA were graded excellent/good. MRA showed 100% specificity for detecting feeding arteries and venous drainage (n = 8) and complete obliteration of the AVM in 2 cases (concordance with CCA). Nidus diameters measured by both MRA and CCA resulted in a very strong correlation (r = 0.99) with a mild overestimation by MRA (0.10 cm by using the Bland-Altman plot). By combining highly temporally resolved and highly spatially resolved MRA at 3T as complementary studies, one can assess vascular anatomy and hemodynamics noninvasively in patients with AVM.

A prospective, multicenter, randomized trial of the Onyx liquid embolic system and N-butyl cyanoacrylate embolization of cerebral arteriovenous malformations. Clinical article.

PubMed

Loh, Yince; Duckwiler, Gary R

2010-10-01

The Onyx liquid embolic system (Onyx) was approved in the European Union in 1999 for embolization of lesions in the intracranial and peripheral vasculature, including brain arteriovenous malformations (AVMs) and hypervascular tumors. In 2001 a prospective, equivalence, multicenter, randomized controlled trial was initiated to support a submission for FDA approval. The objective of this study was to verify the safety and efficacy of Onyx compared with N-butyl cyanoacrylate (NBCA) for the presurgical treatment of brain AVMs. One hundred seventeen patients with brain AVMs were treated with either Onyx (54 patients) or NBCA (63 patients) for presurgical endovascular embolization between May 2001 and April 2003. The primary end point was technical success in achieving ≥ 50% reduction in AVM volume. Secondary end points were operative blood loss and resection time. All adverse events (AEs) were reported and assigned a relationship to the Onyx or NBCA system, treatment, disease, surgery, or other/unknown. The Data Safety Monitoring Board adjudicated AEs, and a blinded, independent core lab assessed volume measurements. Patients were monitored through discharge after the final surgery or through a 3- and/or 12-month follow-up if resection had not been performed or was incomplete. The use of Onyx led to ≥ 50% AVM volume reduction in 96% of cases versus 85% for NBCA (p = not significant). The secondary end points of resection time and blood loss were similar. Serious AEs were also similar between the 2 treatment groups. Onyx is equivalent to NBCA in safety and efficacy as a preoperative embolic agent in reducing brain AVM volume by at least 50%.

Automatic publishing ISO 19115 metadata with PanMetaDocs using SensorML information

NASA Astrophysics Data System (ADS)

Stender, Vivien; Ulbricht, Damian; Schroeder, Matthias; Klump, Jens

2014-05-01

Terrestrial Environmental Observatories (TERENO) is an interdisciplinary and long-term research project spanning an Earth observation network across Germany. It includes four test sites within Germany from the North German lowlands to the Bavarian Alps and is operated by six research centers of the Helmholtz Association. The contribution by the participating research centers is organized as regional observatories. A challenge for TERENO and its observatories is to integrate all aspects of data management, data workflows, data modeling and visualizations into the design of a monitoring infrastructure. TERENO Northeast is one of the sub-observatories of TERENO and is operated by the German Research Centre for Geosciences (GFZ) in Potsdam. This observatory investigates geoecological processes in the northeastern lowland of Germany by collecting large amounts of environmentally relevant data. The success of long-term projects like TERENO depends on well-organized data management, data exchange between the partners involved and on the availability of the captured data. Data discovery and dissemination are facilitated not only through data portals of the regional TERENO observatories but also through a common spatial data infrastructure TEODOOR (TEreno Online Data repOsitORry). TEODOOR bundles the data, provided by the different web services of the single observatories, and provides tools for data discovery, visualization and data access. The TERENO Northeast data infrastructure integrates data from more than 200 instruments and makes data available through standard web services. Geographic sensor information and services are described using the ISO 19115 metadata schema. TEODOOR accesses the OGC Sensor Web Enablement (SWE) interfaces offered by the regional observatories. In addition to the SWE interface, TERENO Northeast also published data through DataCite. The necessary metadata are created in an automated process by extracting information from the SWE SensorML to create ISO 19115 compliant metadata. The resulting metadata file is stored in the GFZ Potsdam data infrastructure. The publishing workflow for file based research datasets at GFZ Potsdam is based on the eSciDoc infrastructure, using PanMetaDocs (PMD) as the graphical user interface. PMD is a collaborative, metadata based data and information exchange platform [1]. Besides SWE, metadata are also syndicated by PMD through an OAI-PMH interface. In addition, metadata from other observatories, projects or sensors in TERENO can be accessed through the TERENO Northeast data portal. [1] http://meetingorganizer.copernicus.org/EGU2012/EGU2012-7058-2.pdf

No Pixel Left Behind - Peeling Away NASA's Satellite Swaths

NASA Astrophysics Data System (ADS)

Cechini, M. F.; Boller, R. A.; Schmaltz, J. E.; Roberts, J. T.; Alarcon, C.; Huang, T.; McGann, M.; Murphy, K. J.

2014-12-01

Discovery and identification of Earth Science products should not be the majority effort of scientific research. Search aides based on text metadata go to great lengths to simplify this process. However, the process is still cumbersome and requires too much data download and analysis to down select to valid products. The EOSDIS Global Imagery Browse Services (GIBS) is attempting to improve this process by providing "visual metadata" in the form of full-resolution visualizations representing geophysical parameters taken directly fromt he data. Through the use of accompanying interpretive information such as color legends and the natural visual processing of the human eye, researchers are able to search and filter through data products in a more natural and efficient way. The GIBS "visual metadata" products are generated as representations of Level 3 data or as temporal composites of the Level 2 granule- or swath-based data products projected across a geographic or polar region. Such an approach allows for low-latency tiled access to pre-generated imagery products. For many GIBS users, the resulting image suffices for a basic representation of the underlying data. However, composite imagery presents an insurmountable problem: for areas of spatial overlap within the composite, only one observation is visually represented. This is especially problematic in the polar regions where a significant portion of sensed data is "lost." In response to its user community, the GIBS team coordinated with its stakeholders to begin developing an approach to ensure that there is "no pixel left behind." In this presentation we will discuss the use cases and requirements guiding our efforts, considerations regarding standards compliance and interoperability, and near term goals. We will also discuss opportunities to actively engage with the GIBS team on this topic to continually improve our services.

Transarterial Balloon-assisted Onyx Embolization of Intracranial Arteriovenous Malformations Using a Dual-lumen Balloon Microcatheter: Two Case Reports.

PubMed

Kim, Sang Heum; Kim, Tae Gon; Kong, Min Ho

2017-09-01

The Onyx system has been well established in recent years as a very important material in the treatment of arteriovenous malformations (AVMs). When using the Onyx, it is essential to wait for the creation of a plug around the tip of the catheter, which enables the effective forward penetration of Onyx. Recent reports have shown that the introduction of a dimethyl sulfoxide compatible dual-lumen balloon microcatheter improves the efficiency of AVM embolization. We report our recent experience of two cases of intracranial AVM embolization using Onyx and the transarterial balloon-assisted technique. In both cases, the procedures were successfully performed and the nidus of the AVM was totally occluded in a relatively short time. This technique may enable immediate forward flow and penetration of Onyx without concern about reflux. It may also reduce the procedure time and increase the angiographic occlusion rate. Navigation of the dual-lumen balloon microcatheter nevertheless remains a challenge.

Transarterial Balloon-assisted Onyx Embolization of Intracranial Arteriovenous Malformations Using a Dual-lumen Balloon Microcatheter: Two Case Reports

PubMed Central

Kim, Sang Heum; Kong, Min Ho

2017-01-01

The Onyx system has been well established in recent years as a very important material in the treatment of arteriovenous malformations (AVMs). When using the Onyx, it is essential to wait for the creation of a plug around the tip of the catheter, which enables the effective forward penetration of Onyx. Recent reports have shown that the introduction of a dimethyl sulfoxide compatible dual-lumen balloon microcatheter improves the efficiency of AVM embolization. We report our recent experience of two cases of intracranial AVM embolization using Onyx and the transarterial balloon-assisted technique. In both cases, the procedures were successfully performed and the nidus of the AVM was totally occluded in a relatively short time. This technique may enable immediate forward flow and penetration of Onyx without concern about reflux. It may also reduce the procedure time and increase the angiographic occlusion rate. Navigation of the dual-lumen balloon microcatheter nevertheless remains a challenge. PMID:29159158

[A pregnant patient with spontaneous haemothorax: hereditary haemorrhagic telangiectasia in pregnancy].

PubMed

Mourad, S M; Mies, R; Frenzel, T; Willems, S; van der Heijden, E; Schultze Kool, L J

2016-01-01

The incidence of hereditary haemorrhagic telangiectasia (HHT - Osler-Weber-Rendu disease) in the Netherlands is 1:5000 but approximately 1:1300 in people from the Antilles. The disease is characterised by the development of telangiectasia and arteriovenous malformations (AVMs) that may result in serious morbidity and mortality. A 31-year-old primigravid patient consulted her general practitioner at 31 1/7 weeks gestational age with dyspnoea. She was referred for further diagnostics because of suspected pulmonary embolism. A CT scan showed haemothorax and a bleeding arteriovenous malformation (AVM) in the left lung. Family history suggested the possibility of HHT. After multidisciplinary consideration, a primary caesarean section was performed, followed by embolisation of the AVM during the same surgical session. The patient had a gene mutation consistent with HHT type 2. Pregnant patients with HHT are at risk of serious morbidity, especially if they are not screened for AVMs. A multidisciplinary approach for such patients, with consideration of various scenarios, is highly recommended.

Brain blood vessel segmentation using line-shaped profiles

NASA Astrophysics Data System (ADS)

Babin, Danilo; Pižurica, Aleksandra; De Vylder, Jonas; Vansteenkiste, Ewout; Philips, Wilfried

2013-11-01

Segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, especially for embolization of cerebral aneurysms and arteriovenous malformations (AVMs). In order to perform embolization of the AVM, the structural and geometric information of blood vessels from 3D images is of utmost importance. For this reason, the in-depth segmentation of cerebral blood vessels is usually done as a fusion of different segmentation techniques, often requiring extensive user interaction. In this paper we introduce the idea of line-shaped profiling with an application to brain blood vessel and AVM segmentation, efficient both in terms of resolving details and in terms of computation time. Our method takes into account both local proximate and wider neighbourhood of the processed pixel, which makes it efficient for segmenting large blood vessel tree structures, as well as fine structures of the AVMs. Another advantage of our method is that it requires selection of only one parameter to perform segmentation, yielding very little user interaction.

Introduction to the supratentorial cerebral arteriovenous malformation video supplement.

PubMed

Starke, Robert M; Albuquerque, Felipe C; Lawton, Michael T

2017-07-01

It is with great pleasure that we present this Neurosurgical Focus video supplement on supratentorial cerebral arteriovenous malformations (AVMs). We were privileged to view a remarkable number of outstanding videos demonstrating current state-of-the-art management of brain AVMs using endovascular and microsurgical modalities. Careful and critical review was required to narrow down the submitted videos to a workable volume for this supplement, which reflects the excellent work being done at multiple centers with these lesions. This issue consists of videos that represent modern microsurgical and neuroendovascular techniques for the treatment of supratentorial cerebral AVMs. The videos demonstrate cutting-edge therapies as well as standard ones, which will be valuable to both novice and expert neurointerventionists and neurosurgeons. We are honored to be involved with this project and proud of its content and expert authors. We believe you will enjoy the video content of this supplement and hope that it will raise the collective expertise of our community of AVM surgeons.

Outcome after interventional or conservative management of unruptured brain arteriovenous malformations: a prospective, population-based cohort study.

PubMed

Wedderburn, Catherine J; van Beijnum, Janneke; Bhattacharya, Jo J; Counsell, Carl E; Papanastassiou, Vakis; Ritchie, Vaughn; Roberts, Richard C; Sellar, Robin J; Warlow, Charles P; Al-Shahi Salman, Rustam

2008-03-01

The decision about whether to treat an unruptured brain arteriovenous malformation (AVM) depends on a comparison of the estimated lifetime risk of intracranial haemorrhage with the risks of interventional treatment. We aimed to test whether outcome differs between adults who had interventional AVM treatment and those who did not. All adults in Scotland who were first diagnosed with an unruptured AVM during 1999-2003 (n=114) entered our prospective, population-based study. We compared the baseline characteristics and 3-year outcome of adults who received interventional treatment for their AVM (n=63) with those who did not (n=51). At presentation, adults who were treated were younger (mean 40 vs 55 years of age, 95% CI for difference 9-20; p<0.0001), more likely to present with a seizure (odds ratio 2.4, 95% CI 1.1-5.0), and had fewer comorbidities (median 3 vs 4, p=0.03) than those who were not treated. Despite these baseline imbalances, treated and untreated groups did not differ in progression to Oxford Handicap Scale (OHS) scores of 2-6 (log-rank p=0.12) or 3-6 (log-rank p=0.98) in survival analyses. In a multivariable Cox proportional hazards analysis, the risk of poor outcome (OHS 2-6) was greater in patients who had interventional treatment than in those who did not (hazard ratio 2.5, 95% CI 1.1-6.0) and was greater in patients with a larger AVM nidus (hazard ratio 1.3, 95% CI 1.1-1.7). The treated and untreated groups did not differ in time to an OHS score of 2 or more that was sustained until the end of the third year of follow-up, or in the spectrum of dependence as measured by the OHS at 1, 2, and 3 years of follow-up. Greater AVM size and interventional treatment were associated with worse short-term functional outcome for unruptured AVMs, but the longer-term effects of intervention are unclear.

Cerebrospinal fluid ferritin and albumin index: potential candidates for scoring system to differentiate between bacterial and viral meningitis in children.

PubMed

Jebamalar, Angelin A; Prabhat; Balakrishnapillai, Agiesh K; Parmeswaran, Narayanan; Dhiman, Pooja; Rajendiran, Soundravally

2016-07-01

To evaluate the diagnostic role of cerebrospinal fluid (CSF) ferritin and albumin index (AI = CSF albumin/serum albumin × 1000) in differentiating acute bacterial meningitis (ABM) from acute viral meningitis (AVM) in children. The study included 42 cases each of ABM and AVM in pediatric age group. Receiver operating characteristic (ROC) analysis was carried out for CSF ferritin and AI. Binary logistic regression was also done. CSF ferritin and AI were found significantly higher in ABM compared to AVM. Model obtained using AI and CSF ferritin along with conventional criteria is better than existing models.

Automatic vehicle monitoring systems study. Report of phase O. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1977-01-01

A set of planning guidelines is presented to help law enforcement agencies and vehicle fleet operators decide which automatic vehicle monitoring (AVM) system could best meet their performance requirements. Improvements in emergency response times and resultant cost benefits obtainable with various operational and planned AVM systems may be synthesized and simulated by means of special computer programs for model city parameters applicable to small, medium, and large urban areas. Design characteristics of various AVM systems and the implementation requirements are illustrated and cost estimated for the vehicles, the fixed sites, and the base equipments. Vehicle location accuracies for different RF links and polling intervals are analyzed.

A SensorML-based Metadata Model and Registry for Ocean Observatories: a Contribution from European Projects NeXOS and FixO3

NASA Astrophysics Data System (ADS)

Delory, E.; Jirka, S.

2016-02-01

Discovering sensors and observation data is important when enabling the exchange of oceanographic data between observatories and scientists that need the data sets for their work. To better support this discovery process, one task of the European project FixO3 (Fixed-point Open Ocean Observatories) is dealing with the question which elements are needed for developing a better registry for sensors. This has resulted in four items which are addressed by the FixO3 project in cooperation with further European projects such as NeXOS (http://www.nexosproject.eu/). 1.) Metadata description format: To store and retrieve information about sensors and platforms it is necessary to have a common approach how to provide and encode the metadata. For this purpose, the OGC Sensor Model Language (SensorML) 2.0 standard was selected. Especially the opportunity to distinguish between sensor types and instances offers new chances for a more efficient provision and maintenance of sensor metadata. 2.) Conversion of existing metadata into a SensorML 2.0 representation: In order to ensure a sustainable re-use of already provided metadata content (e.g. from ESONET-FixO3 yellow pages), it is important to provide a mechanism which is capable of transforming these already available metadata sets into the new SensorML 2.0 structure. 3.) Metadata editor: To create descriptions of sensors and platforms, it is not possible to expect users to manually edit XML-based description files. Thus, a visual interface is necessary to help during the metadata creation. We will outline a prototype of this editor, building upon the development of the ESONET sensor registry interface. 4.) Sensor Metadata Store: A server is needed that for storing and querying the created sensor descriptions. For this purpose different options exist which will be discussed. In summary, we will present a set of different elements enabling sensor discovery ranging from metadata formats, metadata conversion and editing to metadata storage. Furthermore, the current development status will be demonstrated.

Radiological aspects of gamma knife radiosurgery for arteriovenous malformations and other non-tumoural disorders of the brain.

PubMed

Guo, W Y

1993-01-01

The aims of the thesis were to investigate stereotaxic procedures in radiosurgery for cerebral arteriovenous malformations (AVMs) and radiation effects of single session high-dose irradiation delivered by gamma knife on the human brain. Investigation of gamma knife radiosurgery in 1,464 patients constitutes the data base of this thesis. High quality stereotaxic angiography is the gold standard targeting imaging in radiosurgery for cerebral AVMs, particularly for small AVMs or residual AVMs after other treatments. For medium and large size AVMs, stereotaxic MR techniques can improve targeting precision and decrease irradiation volume as compared to stereotaxic angiography in selected cases provided that proper pulse sequences are used. Combined treatments, where embolization precedes radiosurgery, can improve amenability of the treatment for large AVMs. This is on condition that the partially embolized nidi are well delineated and the volume of the residual nidi has been decreased to a level where an optimum irradiation can be safely prescribed. Radiologically, adverse radiation effects (ARE) of gamma knife radiosurgery for cerebral AVMs are observed in 16% (131/816) of the patients. The ARE are observed as a focal low attenuation on CT or as a focal high signal on MR image without enhancement in 47% (61/131), and as a peripheral or homogeneous enhancing lesion in 48% (63/131). MR imaging is more sensitive than CT in detecting the ARE. 91% of the ARE are observed within 18 months after radiosurgery and 89% are seen to regress within 18 months. Clinically, symptomatic ARE are only observed in 6% (51/816) and only in half of them, i.e. 3%, are the symptoms permanent. The risk of ARE in radiosurgery for venous angiomas is higher as compared to AVMs. Other mechanisms have probably been employed. In gamma capsulotomy, the necrotic lesions and reaction volumes created by using multiple isocentres of 4 mm collimators are less predictable as compared to that by single isocentre. Volume effects and depreciation of the steep isodose gradient are hypothesised as the leading factors of the inconsistency. Based on the in vivo assessment of the radiation effects observed on the basically normal human brain it is concluded that irradiation volume is strongly related to the radiation effects and is one of the important considerations in decision making for radiosurgery. Volume of brain tissue exposed to irradiation could be minimised and precision of targeting could be maximised provided that a proper stereotaxic imaging is used.(ABSTRACT TRUNCATED AT 400 WORDS)

Dynamic contrast-enhanced MRA at 1.5 T for detection of arteriovenous shunting before and after Onyx embolization of cerebral arteriovenous malformations.

PubMed

Nogueira, Raul G; Bayrlee, Ahmad; Hirsch, Joshua A; Yoo, Albert J; Copen, William A

2013-10-01

Conventional non-invasive angiographic techniques for evaluating cerebral Arteriovenous Malformations (cAVMs) after embolization treatment are limited by their inability to acquire time-resolved images. We describe the use of dynamic contrast-enhanced magnetic resonance angiography (MRA) in the evaluation of residual arteriovenous shunting in cAVMs following Onyx embolization. Six subjects who underwent multimodal MR imaging including dynamic MRA after different stages of endovascular treatment with Onyx were included. Each MRA was assessed for the presence of residual arteriovenous shunting. The results were compared with digital subtraction angiography (DSA). Mean age was 41 years (range, 25-63) and the mean maximum AVM diameter was 5.3 cm (range, 4.7-6.0). Fourteen dynamic MRA were performed using a 1.5 T scanner. Arteriovenous shunting was detected in thirteen of fourteen patients by both dynamic MRA and DSA, with complete agreement between the two techniques. The only MRA without detectable residual arteriovenous shunting was for a subject who had complete treatment with no residual cAVM as confirmed by the DSA images. Dynamic contrast-enhanced MRA is a promising non-invasive modality in identifying residual arteriovenous shunting after different stages of AVM embolization, achieving 100% agreement in this small study. Embolization with Onyx caused no significant image artifact. Copyright © 2013 by the American Society of Neuroimaging.

Bleeding complications after endovascular therapy of cerebral arteriovenous malformations.

PubMed

Heidenreich, J O; Hartlieb, S; Stendel, R; Pietilä, T A; Schlattmann, P; Wolf, K-J; Schilling, A M

2006-02-01

Intracerebral hemorrhages after embolization of arteriovenous malformations (AVMs) are the most dreaded complications of this well-established therapy. Apart from the known risk factors, our center noticed a high incidence of complications during postinterventional monitoring in medical intensive care units (ICUs) and stroke units. We report 125 consecutive interventions performed on 66 patients by using flow-dependent microcatheters and n-butyl cyanoacrylate as the embolic agent. Postinterventional intensive care monitoring was performed in an interdisciplinary operative ICU, a stroke unit, or a medical ICU. Patients were compared with regard to bleeding complications, AVM morphology, embolization result, postinterventional monitoring, and demographic factors. Intracerebral hemorrhages occurred in 7 patients. Significant differences in outcome were found between 66 patients monitored in the interdisciplinary operative ICU from medical ICU or stroke unit. This was also true when adjusted for age and extent of AVM reduction by using exact logistic regression. A partial AVM reduction of >60% was a considerable risk factor for hemorrhage (odds ratio [OR] = 18.8; 95% confidence interval [CI] [1.341, not available]. Age was also an essential risk factor. An age difference of 10 years leads to an OR of 2.545 (95% CI [1.56, 7.35]). A considerable AVM reduction in one session appears to increase the risk of hemorrhage technically. This suggests a distribution of the interventions in many partial steps.

Streamlining Metadata and Data Management for Evolving Digital Libraries

NASA Astrophysics Data System (ADS)

Clark, D.; Miller, S. P.; Peckman, U.; Smith, J.; Aerni, S.; Helly, J.; Sutton, D.; Chase, A.

2003-12-01

What began two years ago as an effort to stabilize the Scripps Institution of Oceanography (SIO) data archives from more than 700 cruises going back 50 years, has now become the operational fully-searchable "SIOExplorer" digital library, complete with thousands of historic photographs, images, maps, full text documents, binary data files, and 3D visualization experiences, totaling nearly 2 terabytes of digital content. Coping with data diversity and complexity has proven to be more challenging than dealing with large volumes of digital data. SIOExplorer has been built with scalability in mind, so that the addition of new data types and entire new collections may be accomplished with ease. It is a federated system, currently interoperating with three independent data-publishing authorities, each responsible for their own quality control, metadata specifications, and content selection. The IT architecture implemented at the San Diego Supercomputer Center (SDSC) streamlines the integration of additional projects in other disciplines with a suite of metadata management and collection building tools for "arbitrary digital objects." Metadata are automatically harvested from data files into domain-specific metadata blocks, and mapped into various specification standards as needed. Metadata can be browsed and objects can be viewed onscreen or downloaded for further analysis, with automatic proprietary-hold request management.

[Tentorial dural arteriovenous malformation--a case report (author's transl)].

PubMed

Miyagi, K; Iwasa, H; Yoshimizu, N; Masuzawa, T; Ishijima, B

1976-12-01

A case of tentorial dural AVM was reported. A 52 years old man came to the Jichi Medical School hospital on July 29, 1974, with the chief complaints of intermittent left exophthalmos, diplopia and left blepharoptosis, which had been noted since March of 1974. He had episodes of severe headache attack since 3 years prior to the hospital visit. Angiography done at the out-patient department demonstrated the dural AVM with the nidus in the left tentorium. The nidus was fed by the left posterior middle meningeal artery, the dural branch of the left occipital artery, the left posterior cerebral artery, the left superior cerebellar artery and the dural branches of vertebral artery. It was drained to the vein of Labbé and the two cortical veins of the occipital lobe. He was appointing admission under the diagnosis of dural AVM, but he had an apopleptic attack three days before the appointed date, so was admitted in emergency. Neurological examination on admission: The patient was in drowsy state, papilledema on the both sides and right hemiparesis including the face were noted. The bruit was not audible. Left CAG revealed intracerebral hematoma in the left tempotal lobe, so that the removal of the intracerebral hematoma and the middle meningeal artery ligation were carried out after his general condition improved, on October 18, 1974. On October 30, 1974, the second operation was performed in an attempt of the radical excision of the AVM nidud. But, unfortunately, the patient fell into the shock state so that the operation had to be stopped at the stage of the ligation of the feeders running in the dura of the posterior fossa. The third operation was done on February 19, 1975. The AVM nidus was removed with the left transverse sinus and a part of tentorium. He was discharged on March 3, 1975, with only the right homonymous hemianopsia. Nine months after his discharge, there was no sign of recurrence of AVM. The left transverse sinus was almost occupied with AVM tissue. The endothelium of arteries were hypertrophied and the internal elastic bnadles were partly defected. Veins showed also hspertrophy of the endothelium and the thrombus formation. The dural AVM of the posterior fossa is not a rare malady, especially in the recent years, probably due to the technical advances in the roentgenology, such as magnification techniques as well as selective arterial catheterization. The most common signs and symptoms of this disease picked up from the reports of 112 cases in the literature are: bruit 47%, headache 44%, papilledema 26% and SAH 24%. The extra cranial ligation of feeders were reportedly carried out on 39 cases, but only 9 cases (23%) were effective. Therefore, the radical excision of the nidus would be the most desirable method for the complete treatment of the dural AVM.

Hardware design for the Autonomous Visibility Monitoring (AVM) observatory

NASA Technical Reports Server (NTRS)

Cowles, K.

1993-01-01

The hardware for the three Autonomous Visibility Monitoring (AVM) observatories was redesigned. Changes in hardware design include electronics components, weather sensors, and the telescope drive system. Operation of the new hardware is discussed, as well as some of its features. The redesign will allow reliable automated operation.

Diagnosis and Nonsurgical Management of Uterine Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rangarajan, R. D.; Moloney, J. C.; Anderson, H. J.

Uterine arteriovenous malformation (AVM) is an uncommon problem and traditional treatment by hysterectomy excludes the possibility of future pregnancy. Developments in interventional techniques make transcatheter embolization of the feeding vessel(s) a therapeutic alternative, potentially preserving the patient's fertility. We present a case of successful endovascular treatment of uterine AVM.

Comprehensive Field Test and Evaluation of an Electronic Signpost AVM System. Volume I. Test Results

DOT National Transportation Integrated Search

1977-08-01

The report covers the activities of Phase I which involved the installation and test of a HI3 AVM System in Philadelphia, Pennsylvania, during the winter of 1976-1977. A summary report on all systems tested is Experiments on four different techniques...

Cambio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, William

2015-10-19

Cambio opens data files from common gamma radiation detectors, displays a visual representation of it, and allows the user to edit the meta-data, as well as convert the data to a different file format.

Contralateral posterior interhemispheric approach to deep medial parietooccipital vascular malformations: surgical technique and results.

PubMed

Burkhardt, Jan-Karl; Winkler, Ethan A; Lawton, Michael T

2017-07-21

OBJECTIVE Deep medial parietooccipital arteriovenous malformations (AVMs) and cerebral cavernous malformations (CCMs) are traditionally resected through an ipsilateral posterior interhemispheric approach (IPIA), which creates a deep, perpendicular perspective with limited access to the lateral margins of the lesion. The contralateral posterior interhemispheric approach (CPIA) flips the positioning, with the midline positioned horizontally for retraction due to gravity, but with the AVM on the upper side and the approach from the contralateral, lower side. The aim of this paper was to analyze whether the perpendicular angle of attack that is used in IPIA would convert to a parallel angle of attack with the CPIA, with less retraction, improved working angles, and no significant increase in risk. METHODS A retrospective review of pre- and postoperative clinical and radiographic data was performed in 8 patients who underwent a CPIA. RESULTS Three AVMs and 5 CCMs were resected using the CPIA, with an average nidus size of 2.3 cm and CCM diameter of 1.7 cm. All lesions were resected completely, as confirmed on postoperative catheter angiography or MRI. All patients had good neurological outcomes, with either stable or improved modified Rankin Scale scores at last follow-up. CONCLUSIONS The CPIA is a safe alternative approach to the IPIA for deep medial parietooccipital vascular malformations that extend 2 cm or more off the midline. Contralaterality and retraction due to gravity optimize the interhemispheric corridor, the surgical trajectory to the lesion, and the visualization of the lateral margin, without resection or retraction of adjacent normal cortex. Although the falx is a physical barrier to accessing the lesion, it stabilizes the ipsilateral hemisphere while gravity delivers the dissected lesion through the transfalcine window. Patient positioning, CSF drainage, venous preservation, and meticulous dissection of the deep margins are critical to the safety of this approach.

Semantics-based distributed I/O with the ParaMEDIC framework.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balaji, P.; Feng, W.; Lin, H.

2008-01-01

Many large-scale applications simultaneously rely on multiple resources for efficient execution. For example, such applications may require both large compute and storage resources; however, very few supercomputing centers can provide large quantities of both. Thus, data generated at the compute site oftentimes has to be moved to a remote storage site for either storage or visualization and analysis. Clearly, this is not an efficient model, especially when the two sites are distributed over a wide-area network. Thus, we present a framework called 'ParaMEDIC: Parallel Metadata Environment for Distributed I/O and Computing' which uses application-specific semantic information to convert the generatedmore » data to orders-of-magnitude smaller metadata at the compute site, transfer the metadata to the storage site, and re-process the metadata at the storage site to regenerate the output. Specifically, ParaMEDIC trades a small amount of additional computation (in the form of data post-processing) for a potentially significant reduction in data that needs to be transferred in distributed environments.« less

Development of an oil spill information system combining remote sensing data and surveillance metadata

NASA Astrophysics Data System (ADS)

Tufte, Lars; Trieschmann, Olaf; Carreau, Philippe; Hunsaenger, Thomas; Clayton, Peter J. S.; Barjenbruch, Ulrich

2004-02-01

The detection of accidentally or illegal marine oil discharges in the German territorial waters of the North Sea and Baltic Sea is of great importance for combating of oil spills and protection of the marine ecosystem. Therefore the German Federal Ministry of Transport set up an airborne surveillance system consisting of two Dornier DO 228-212 aircrafts equipped with a Side-Looking Airborne Radar (SLAR), a IR/UV sensor, a Microwave Radiometer (MWR) for quantification and a Laser-Flurosensor (LFS) for classification purposes of the oil spills. The flight parameters and the remote sensing data are stored in a database during the flight. A Pollution Observation Log is completed by the operator consisting of information about the detected oil spill (e.g. position, length, width) and several other information about the flight (e.g. name of navigator, name of observer). The objective was to develop an oil spill information system which integrates the described data, metadata and includes visualization and spatial analysis capabilities. The metadata are essential for further statistical analysis in spatial and temporal domains of oil spill occurrences and of the surveillance itself. It should facilitate the communication and distribution of metadata between the administrative bodies and partners of the German oil spill surveillance system. A connection between a GIS and the database allows to use the powerful visualization and spatial analysis functionality of the GIS in conjunction with the oil spill database.

Texture-Based Correspondence Display

NASA Technical Reports Server (NTRS)

Gerald-Yamasaki, Michael

2004-01-01

Texture-based correspondence display is a methodology to display corresponding data elements in visual representations of complex multidimensional, multivariate data. Texture is utilized as a persistent medium to contain a visual representation model and as a means to create multiple renditions of data where color is used to identify correspondence. Corresponding data elements are displayed over a variety of visual metaphors in a normal rendering process without adding extraneous linking metadata creation and maintenance. The effectiveness of visual representation for understanding data is extended to the expression of the visual representation model in texture.

Application of Onyx for Renal Arteriovenous Malformation With First Case Report of a Renal Hyperdense Striation Sign

PubMed Central

Juan, Yu-Hsiang; Lin, Yu-Ching; Sheng, Ting-Wen; Cheung, Yun-Chung; Ng, Shu-Hang; Yu, Chin-Wei; Wong, Ho-Fai

2015-01-01

Abstract Onyx is an emerging treatment modality for visceral vascular malformations, especially in cases in which delicate nidal penetration of the arteriovenous malformation (AVM) is desired. A computed tomography (CT) image presentation of hyperdense striations along the renal medulla secondary to the tantalum powder has not been previously reported. A 65-year-old woman presented to our institution with intermittent gross hematuria and left flank pain for 10 days. Both CT and conventional angiographies confirmed cirsoid-type renal AVM, which was successfully treated with Onyx. Follow-up CT after treatment revealed presence of hyperdense striations along the renal medulla, which resolved during later image follow-up. Despite its frequent usage in neural intervention, the application of Onyx in visceral AVM is gradually gaining interest, especially in cases in which delicate nidal penetration of the AVM is desired. Renal hyperdense striation sign should be recognized to avoid confusion with embolizer migration, and further studies in patients with renal function impairment may be helpful in understanding its influence of renal function. PMID:26426661

Arteriovenous malformation of the vestibulocochlear nerve

PubMed Central

Tucker, Adam; Tsuji, Masao; Yamada, Yoshitaka; Hanabusa, Kenichiro; Ukita, Tohru; Miyake, Hiroji; Ohmura, Takehisa

2015-01-01

We describe a rare case of an arteriovenous malformation (AVM) embedded in the vestibulocochlear nerve presenting with subarachnoid hemorrhage (SAH) treated by microsurgical elimination of the main feeding artery and partial nidus volume reduction with no permanent deficits. This 70-year-old woman was incidentally diagnosed 4 years previously with two small unruptured tandem aneurysms (ANs) on the right anterior inferior cerebral artery feeding a small right cerebellopontine angle AVM. The patient was followed conservatively until she developed sudden headache, nausea and vomiting and presented to our outpatient clinic after several days. Magnetic resonance imaging demonstrated findings suggestive of early subacute SAH in the quadrigeminal cistern. A microsurgical flow reduction technique via clipping between the two ANs and partial electrocoagulation of the nidus buried within the eighth cranial nerve provided radiographical devascularization of the ANs with residual AVM shunt flow and no major deficits during the 2.5 year follow-up. This is only the second report of an auditory nerve AVM. In the event of recurrence, reoperation or application of alternative therapies may be considered. PMID:26244159

Computational modelling for the embolization of brain arteriovenous malformations.

PubMed

Orlowski, Piotr; Summers, Paul; Noble, J Alison; Byrne, James; Ventikos, Yiannis

2012-09-01

Treatment of arteriovenous malformations (AVMs) of the brain often requires the injection of a liquid embolic material to reduce blood flow through the malformation. The type of the liquid and the location of injection have to be carefully planned in a pre-operative manner. We introduce a new model of the interaction of liquid embolic materials with blood for the simulation of their propagation and solidification in the AVM. Solidification is mimicked by an increase of the material's viscosity. Propagation is modelled by using the concept of two-fluids modelling and that of scalar transport. The method is tested on digital phantoms and on one anatomically derived patient AVM case. Simulations showed that intuitive behaviour of the two-fluid system can be confirmed and that two types of glue propagation through the malformation can be reproduced. Distinction between the two types of propagation could be used to identify fistulous and plexiform compartments composing the AVM and to characterize the solidification of the embolic material in them. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Metadata management for high content screening in OMERO

PubMed Central

Li, Simon; Besson, Sébastien; Blackburn, Colin; Carroll, Mark; Ferguson, Richard K.; Flynn, Helen; Gillen, Kenneth; Leigh, Roger; Lindner, Dominik; Linkert, Melissa; Moore, William J.; Ramalingam, Balaji; Rozbicki, Emil; Rustici, Gabriella; Tarkowska, Aleksandra; Walczysko, Petr; Williams, Eleanor; Allan, Chris; Burel, Jean-Marie; Moore, Josh; Swedlow, Jason R.

2016-01-01

High content screening (HCS) experiments create a classic data management challenge—multiple, large sets of heterogeneous structured and unstructured data, that must be integrated and linked to produce a set of “final” results. These different data include images, reagents, protocols, analytic output, and phenotypes, all of which must be stored, linked and made accessible for users, scientists, collaborators and where appropriate the wider community. The OME Consortium has built several open source tools for managing, linking and sharing these different types of data. The OME Data Model is a metadata specification that supports the image data and metadata recorded in HCS experiments. Bio-Formats is a Java library that reads recorded image data and metadata and includes support for several HCS screening systems. OMERO is an enterprise data management application that integrates image data, experimental and analytic metadata and makes them accessible for visualization, mining, sharing and downstream analysis. We discuss how Bio-Formats and OMERO handle these different data types, and how they can be used to integrate, link and share HCS experiments in facilities and public data repositories. OME specifications and software are open source and are available at https://www.openmicroscopy.org. PMID:26476368

Metadata management for high content screening in OMERO.

PubMed

Li, Simon; Besson, Sébastien; Blackburn, Colin; Carroll, Mark; Ferguson, Richard K; Flynn, Helen; Gillen, Kenneth; Leigh, Roger; Lindner, Dominik; Linkert, Melissa; Moore, William J; Ramalingam, Balaji; Rozbicki, Emil; Rustici, Gabriella; Tarkowska, Aleksandra; Walczysko, Petr; Williams, Eleanor; Allan, Chris; Burel, Jean-Marie; Moore, Josh; Swedlow, Jason R

2016-03-01

High content screening (HCS) experiments create a classic data management challenge-multiple, large sets of heterogeneous structured and unstructured data, that must be integrated and linked to produce a set of "final" results. These different data include images, reagents, protocols, analytic output, and phenotypes, all of which must be stored, linked and made accessible for users, scientists, collaborators and where appropriate the wider community. The OME Consortium has built several open source tools for managing, linking and sharing these different types of data. The OME Data Model is a metadata specification that supports the image data and metadata recorded in HCS experiments. Bio-Formats is a Java library that reads recorded image data and metadata and includes support for several HCS screening systems. OMERO is an enterprise data management application that integrates image data, experimental and analytic metadata and makes them accessible for visualization, mining, sharing and downstream analysis. We discuss how Bio-Formats and OMERO handle these different data types, and how they can be used to integrate, link and share HCS experiments in facilities and public data repositories. OME specifications and software are open source and are available at https://www.openmicroscopy.org. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Impact on cognitive functions following gamma knife radiosurgery for cerebral arteriovenous malformations.

PubMed

Raghunath, A; Bennett, Niranjana; Arimappamagan, Arivazhagan; Bhat, Dhananjaya I; Srinivas, Dwarakanath; Thennarasu, K; Jamuna, R; Somanna, Sampath

2016-01-01

Radiosurgery is an alternative to surgical resection of arteriovenous malformation (AVM). Very few studies have addressed the concern of radiation injury to the brain and its attendant adverse effects on cognitive function. This prospective study included all patients who underwent gamma knife radiosurgery (GKRS) at our institute for cerebral AVM between 2006 and December 2008 (n = 34). All patients underwent neuropsychological evaluation before the procedure. Neuropsychological evaluation was repeated in eighteen patients 2 years following GKRS. Clinical outcome, AVM obliteration, and factors influencing outcome were analyzed in these eighteen patients. Before GKRS, more than 50% had significant impairment of neuropsychological functions compared to normal population norms. 66.6% achieved the excellent radiosurgical outcome. At 2 years follow-up, patients showed varied improvement in neuropsychological function in various categories. Pretherapeutic median value for percentage perseverative responses was 26.5 and at follow-up, it reduced to 18.2 (P = 0.039). Set shifting improved in 11 patients (61.1%), remained same in 5 patients (27.7%), and deteriorated in two patients (11.1%). Patients with a higher Spetzler-Martin grade AVM demonstrated a significantly more favorable shift in follow-up test values for set shifting function (P = 0.021). Patients with postradiation imaging changes had lesser tendency to improve in neuropsychological performance at follow-up. GKRS has no clinically harmful effect on cognitive and neuropsychological functioning in patients with brain AVM. On the contrary, there is an improvement in majority of patients at 2 years following radiosurgery when nidus is obliterated.

Axon Response to Guidance Cues Is Stimulated by Acetylcholine in Caenorhabditis elegans

PubMed Central

Xu, Yan; Ren, Xing-Cong; Quinn, Christopher C.; Wadsworth, William G.

2011-01-01

Gradients of acetylcholine can stimulate growth cone turning when applied to neurons grown in culture, and it has been suggested that acetylcholine could act as a guidance cue. However, the role acetylcholine plays in directing axon migrations in vivo is not clear. Here, we show that acetylcholine positively regulates signaling pathways that mediate axon responses to guidance cues in Caenorhabditis elegans. Mutations that disrupt acetylcholine synthesis, transportation, and secretion affect circumferential axon guidance of the AVM neuron and in these mutants exogenously supplied acetylcholine improves AVM circumferential axon guidance. These effects are not observed for the circumferential guidance of the DD and VD motor neuron axons, which are neighbors of the AVM axon. Circumferential guidance is directed by the UNC-6 (netrin) and SLT-1 (slit) extracellular cues, and exogenously supplied acetylcholine can improve AVM axon guidance in mutants when either UNC-6– or SLT-1–induced signaling is disrupted, but not when both signaling pathways are perturbed. Not in any of the mutants does exogenously supplied acetylcholine improve DD and VD axon guidance. The ability of acetylcholine to enhance AVM axon guidance only in the presence of either UNC-6 or SLT-1 indicates that acetylcholine potentiates UNC-6 and SLT-1 guidance activity, rather than acting itself as a guidance cue. Together, our results show that for specific neurons acetylcholine plays an important role in vivo as a modulator of axon responses to guidance cues. PMID:21868605

Comparison, analysis, and estimation of discharge data from two acoustic velocity meters on the Chicago Sanitary and Ship Canal at Romeoville, Illinois

USGS Publications Warehouse

Melching, Charles S.; Oberg, Kevin A.

1993-01-01

The acoustic velocity meter (AVM) on the Chicago Sanitary and Ship Canal (the Canal) at Romeoville, Ill., provides vital information for the accounting of the diversion of water from Lake Michigan. A detailed analysis of the discharge record on the Canal at Romeoville was done by the U.S. Geological Survey to establish the most accurate estimates of discharge for water years 1986-91. The analysis involved (1) checking the consistency of the discharges estimated by two different AVM's installed at Romeoville for consecutive time periods by statistical and regression analyses, (2) adjusting the discharge record to account for corrections to the width and depth of the Canal determined by field measurements, and (3) development of equations for estimating discharge on days when the AVM was inoperative using discharge estimates made by the Metropolitan Water Reclamation District of Greater Chicago at the lock, powerhouse, and controlling works at Lockport, Ill. No signi- ficant difference in the discharge estimates made by the two AVM's could be documented. The estimation equations combined regression analysis with physical principles of the outlet-works operation. The estimation equations simulated the verification period of October 1, 1991, to May 31, 1992, within 0.22, 5.15, and 0.66 percent for the mean, standard deviation, and skewness coefficient, respectively. Discharges were recalculated for the corrected width and depth, estimated for the periods of AVM inoperation, and entered into the discharge record for the station.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buis, Dennis R.; Lagerwaard, Frank J.; Dirven, Clemens M.F.

Purpose: To assess the dosimetric consequences of brain arteriovenous malformation (bAVM) delineation on magnetic resonance angiography (MRA) for the purpose of stereotactic radiosurgery. Methods and Materials: Three observers contoured a bAVM in 20 patients, using digital subtraction angiography (V{sub DSA}) and three-dimensional time-of-flight MRA (V{sub MRA}). Displacement between contours was calculated. Agreement and differences between observers and imaging modalities were assessed. A standardized treatment plan with dynamic conformal arcs was generated and dosimetric coverage of all contours and the volume of normal brain tissue within the high dose region was determined. Results: The generalized reliability coefficient was 'fair' for targetmore » volume (0.79), but 'poor' for displacement (0.35). V{sub MRA} was larger than V{sub DSA} (5.0 vs. 4.0 mL, p = 0.001). No difference in displacement was found (2.8 vs. 2.5 mm, p = 0.156). Dosimetric coverage of V{sub MRA} was 62.9% (95% CI, 56.9-68.8) when V{sub DSA} was used as planning target volume, and coverage of V{sub DSA} was 83.5% (95% CI, 78.1-88.8) when V{sub MRA} was used for planning (p < 0.001). The mean volume of normal brain within the 80% isodose was larger when the bAVM was delineated on MRA (0.7 vs. 1.0 mL (p = 0.02) for targets {<=}3 mL and 3.7 vs. 7.0 mL (p = 0.01) for targets >3 mL). Conclusions: Brain arteriovenous malformations delineated on MRA are larger and more randomly displaced. However, for bAVMs {<=}3 mL, the difference in volume of normal brain tissue within the high-dose region does not seem to be clinically relevant. Therefore, MRA-images might be used as the sole imaging modality for the radiosurgical treatment of bAVMs {<=}3 mL when the bAVM is located in a noneloquent position.« less

Onyx embolization of intracranial arteriovenous malformations in pediatric patients.

PubMed

Soltanolkotabi, Maryam; Schoeneman, Samantha E; Alden, Tord D; Hurley, Michael C; Ansari, Sameer A; DiPatri, Arthur J; Tomita, Tadanori; Shaibani, Ali

2013-04-01

The authors undertook this study to assess the safety and efficacy of Onyx embolization in the treatment of intracranial arteriovenous malformations (AVMs) in pediatric patients. All pediatric Onyx embolization of intracranial AVM cases performed consecutively at a single children's hospital over a 5-year period were collected and evaluated. Twenty-five patients (mean age 10.5 years) underwent a total of 38 procedures. An aggregate of 56 pedicles were embolized (mean 1.47 per session). The Spetzler-Martin grade was determined in all cases. Onyx embolization resulted in complete obliteration of the AVM in 3 cases (12%) and partial obliteration in 22 cases (88%). A total of 23 patients underwent surgical treatment. The mean preoperative AVM devascularization in these cases was 72%. One patient was treated with radiosurgery following Onyx embolization. Overall, 10 complications occurred in a total of 38 procedures (26.3%). None of the complications resulted in permanent neurological morbidity. The rate of transient neurological complications was 10.5% (4 of 38 procedures) and the rate of transient nonneurological complications was 5.3% (2 of 38 procedures). The remaining 4 complications were clinically silent (rate of 10.5%). There were no procedure-related deaths in this study population. There was no significant difference in patients with and without complications in terms of demographic characteristics, AVM grade, or embolization features (p ≥ 0.2). Deep venous drainage was associated with higher complication rates (p = 0.03). Onyx utilization is feasible for preoperative or primary embolization in the treatment of pediatric intracranial AVMs; however, the spectrum of complications encountered is broad, and attention must be paid to the technical nuances of and indications for its use to avoid many potential dangerous effects. Although the overall complication rates were higher than expected, all were either clinically silent or had only transient clinical effects. Thus, this experience suggests that Onyx embolization can be performed safely with a low rate of permanent morbidity in pediatric patients harboring these difficult lesions.

Planned Two-Fraction Proton Beam Stereotactic Radiosurgery for High-Risk Inoperable Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hattangadi, Jona A.; Chapman, Paul H.; Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA

2012-06-01

Purpose: To evaluate patients with high-risk cerebral arteriovenous malformations (AVMs), based on eloquent brain location or large size, who underwent planned two-fraction proton stereotactic radiosurgery (PSRS). Methods and Materials: From 1991 to 2009, 59 patients with high-risk cerebral AVMs received two-fraction PSRS. Median nidus volume was 23 cc (range, 1.4-58.1 cc), 70% of cases had nidus volume {>=}14 cc, and 34% were in critical locations (brainstem, basal ganglia). Median AVM score based on age, AVM size, and location was 3.19 (range, 0.9-6.9). Many patients had prior surgery or embolization (40%) or prior PSRS (12%). The most common prescription was 16more » Gy radiobiologic equivalent (RBE) in two fractions, prescribed to the 90% isodose. Results: At a median follow-up of 56.1 months, 9 patients (15%) had total and 20 patients (34%) had partial obliteration. Patients with total obliteration received higher total dose than those with partial or no obliteration (mean dose, 17.6 vs. 15.5 Gy (RBE), p = 0.01). Median time to total obliteration was 62 months (range, 23-109 months), and 5-year actuarial rate of partial or total obliteration was 33%. Five-year actuarial rate of hemorrhage was 22% (95% confidence interval, 12.5%-36.8%) and 14% (n = 8) suffered fatal hemorrhage. Lesions with higher AVM scores were more likely to hemorrhage (p = 0.024) and less responsive to radiation (p = 0.026). The most common complication was Grade 1 headache acutely (14%) and long term (12%). One patient developed a Grade 2 generalized seizure disorder, and two had mild neurologic deficits. Conclusions: High-risk AVMs can be safely treated with two-fraction PSRS, although total obliteration rate is low and patients remain at risk for future hemorrhage. Future studies should include higher doses or a multistaged PSRS approach for lesions more resistant to obliteration with radiation.« less

Standards-based metadata procedures for retrieving data for display or mining utilizing persistent (data-DOI) identifiers.

PubMed

Harvey, Matthew J; Mason, Nicholas J; McLean, Andrew; Rzepa, Henry S

2015-01-01

We describe three different procedures based on metadata standards for enabling automated retrieval of scientific data from digital repositories utilising the persistent identifier of the dataset with optional specification of the attributes of the data document such as filename or media type. The procedures are demonstrated using the JSmol molecular visualizer as a component of a web page and Avogadro as a stand-alone modelling program. We compare our methods for automated retrieval of data from a standards-compliant data repository with those currently in operation for a selection of existing molecular databases and repositories. Our methods illustrate the importance of adopting a standards-based approach of using metadata declarations to increase access to and discoverability of repository-based data. Graphical abstract.

Treatment of arteriovenous malformations involving the hand.

PubMed

Park, Ui-Jun; Do, Young-Soo; Park, Kwang-Bo; Park, Hong-Suk; Kim, Young-Wook; Lee, Byung-Boong; Kim, Dong-Ik

2012-07-01

Hand arteriovenous malformations (AVMs) are difficult to treat because of the necessity to maintain function and the high complication rate of treatment. The purpose of this study was to review the treatment of hand AVMs with embolo/sclerotherapy and the surgical procedures at a single institute. We retrospectively reviewed the medical records and identified the patients who were referred to the vascular division owing to hand AVMs between 1995 and 2009. The lesions were classified according to their affected areas. The treatments used at the clinic included conservative treatment, amputation, and embolo/sclerotherapy. We investigated the clinical data and assessed the treatment results. Sixty-four patients were involved in this study. The median follow-up duration was 26.9 months (range: 3.5-141.8 months). The median age of the patients was 31.5 years (range: 0.3-75.0 years). All of the lesions were of the extratruncal (ET) form, and 37 cases (57.8%) were of the infiltrating type. Sixteen patients were treated conservatively. Primary amputation was performed in seven cases with previous complications such as ulcer, bleeding, or functional limitations. Embolo/sclerotherapy with ethanol was performed in 41 patients. Sixteen (39.0%) of them showed clinical improvement. The treatment of 20 (48.8%) of the 41 patients was interrupted owing to a variety of complications, and 2 (4.9%) of these patients failed with embolo/sclerotherapy. Skin necrosis was the major complication, and this occurred in 17 patients treated with embolo/sclerotherapy--14 of these cases were small and the skin necrosis healed with conservative treatment; 1 patient had autoamputation owing to necrosis; and 2 patients underwent amputation surgery owing to gangrene. The risk for skin necrosis was higher for the AVMs that involved the subcutaneous layer and the AVMs that extended diffusely (P = 0.021, P = 0.011). Seven neuropathic complications developed after embolo/sclerotherapy, and all of them were transient. The symptoms and characteristics of the lesions are important factors in devising a treatment plan for AVMs. AVM treatment, and especially embolo/sclerotherapy, is a long-term prospect, and it carries a potential risk for serious complications. After every treatment, the lesions must be reevaluated and new treatment plans must be made by the members of a multidisciplinary team. Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

Radiosurgery reduces plasma levels of angiogenic factors in brain arteriovenous malformation patients.

PubMed

Xu, Ming; Liu, Xiaoxia; Mei, Guanghai; Zhang, Junjie; Wang, Weixing; Xu, Hongzhi

2018-05-09

Aberrant expression of angiogenic factors has been anecdotally documented in brain arteriovenous malformation (AVM) nidus vessels; however, no data is available on the effect of radiosurgery on the levels of angiogenic factors in AVM patients. We sought to determine the plasma contents of VEGF, TGF-β, Ang-2 and bFGF in 28 brain AVM patients at baseline and post radiosurgery and further analyzed the relationship between plasma contents of these angiogenic factors with clinicopathologic variables of these patients. We enrolled brain AVM patients who underwent Cyberknife radiosurgery at our hospital between January 2014 and December 2015. Brain AVM was confirmed by cerebral angiography and radiosurgery was performed with Cyberknife irradiation. Plasma contents of VEGF, TGF-β, Ang-2 and bFGF were analyzed using commercially available enzyme-linked immunoassay (ELISA) kits. The baseline plasma VEGF content was 222.63 pg/mL (range 43.25-431.25 pg/mL). At three months post surgery, there was a significant -34.29% decline in plasma VEGF content versus baseline (P = 0.000). Furthermore, the median baseline plasma VEGF levels were higher in brain AVM with a nidus volume ≥ 10 cm 3 ) than those with a nidus volume < 10 cm 3 [median(IQR) 293.5 (186.5,359.25) vs. 202 (59.75, 270.75) pg/mL, P = 0.057]. The baseline plasma TGF-β content was 556.17 pg/mL (range 44.44-1486.11 pg/mL) and there was a significant -27.47% decline in plasma TGF-β content at 3 months post radiosurgery versus baseline (P = 0.015). Moreover, the baseline plasma ANG-2 content was 214.27 pg/mL (range 77.14-453.76 pg/mL). There was an immediate and significant -12.47% decline in plasma ANG-2 content post surgery versus baseline (P = 0.002). At three months post surgery, the plasma ANG-2 content still remained significantly depressed versus baseline (P = 0.002). In addition, the baseline plasma bFGF content was 9.17 pg/mL (range 3.67-36.78 pg/mL). No significant difference in plasma bFGF content was observed immediately post surgery and 3 months post surgery versus baseline (P = 0.05). Radiosurgery for brain AVM patients significantly reduced the plasma levels of angiogenic factors. The plasma angiogenic factors may be candidate markers for aberrant agniogenesis of brain AVM and patient response to radiosurgery. Copyright © 2018 Elsevier Inc. All rights reserved.

Towards a semantic medical Web: HealthCyberMap's tool for building an RDF metadata base of health information resources based on the Qualified Dublin Core Metadata Set.

PubMed

Boulos, Maged N; Roudsari, Abdul V; Carson, Ewart R

2002-07-01

HealthCyberMap (http://healthcybermap.semanticweb.org/) aims at mapping Internet health information resources in novel ways for enhanced retrieval and navigation. This is achieved by collecting appropriate resource metadata in an unambiguous form that preserves semantics. We modelled a qualified Dublin Core (DC) metadata set ontology with extra elements for resource quality and geographical provenance in Prot g -2000. A metadata collection form helps acquiring resource instance data within Prot g . The DC subject field is populated with UMLS terms directly imported from UMLS Knowledge Source Server using UMLS tab, a Prot g -2000 plug-in. The project is saved in RDFS/RDF. The ontology and associated form serve as a free tool for building and maintaining an RDF medical resource metadata base. The UMLS tab enables browsing and searching for concepts that best describe a resource, and importing them to DC subject fields. The resultant metadata base can be used with a search and inference engine, and have textual and/or visual navigation interface(s) applied to it, to ultimately build a medical Semantic Web portal. Different ways of exploiting Prot g -2000 RDF output are discussed. By making the context and semantics of resources, not merely their raw text and formatting, amenable to computer 'understanding,' we can build a Semantic Web that is more useful to humans than the current Web. This requires proper use of metadata and ontologies. Clinical codes can reliably describe the subjects of medical resources, establish the semantic relationships (as defined by underlying coding scheme) between related resources, and automate their topical categorisation.

Visualization Beyond the Map: The Challenges of Managing Data for Re-Use

NASA Astrophysics Data System (ADS)

Allison, M. D.; Groman, R. C.; Chandler, C. L.; Galvarino, C. R.; Wiebe, P. H.; Glover, D. M.

2012-12-01

The Biological and Chemical Oceanography Data Management Office (BCO-DMO) makes data publicly accessible via both a text-based and a geospatial interface, the latter using the Open Geospatial Consortium (OGC) compliant open-source MapServer software originally from the University of Minnesota. Making data available for reuse by the widest variety of users is one of the overriding goals of BCO-DMO and one of our greatest challenges. The biogeochemical, ecological and physical data we manage are extremely heterogeneous. Although it is not possible to be all things to all people, we are actively working on ways to make the data re-usable by the most people. Looking at data in a different way is one of the underpinnings of data re-use and the easier we can make data accessible, the more the community of users will benefit. We can help the user determine usefulness by providing some specific tools. Sufficiently well-informed metadata can often be enough to determine fitness for purpose, but many times our geospatial interface to the data and metadata is more compelling. Displaying the data visually in as many ways as possible enables the scientist, teacher or manager to decide if the data are useful and then being able to download the data right away with no login required is very attractive. We will present ways of visualizing different kinds of data and discuss using metadata to drive the visualization tools. We will also discuss our attempts to work with data providers to organize their data in ways to make them reusable to the largest audience and to solicit input from data users about the effectiveness of our solutions.

Overview of long-term field experiments in Germany - metadata visualization

NASA Astrophysics Data System (ADS)

Muqit Zoarder, Md Abdul; Heinrich, Uwe; Svoboda, Nikolai; Grosse, Meike; Hierold, Wilfried

2017-04-01

BonaRes ("soil as a sustainable resource for the bioeconomy") is conducting to collect data and metadata of agricultural long-term field experiments (LTFE) of Germany. It is funded by the German Federal Ministry of Education and Research (BMBF) under the umbrella of the National Research Strategy BioEconomy 2030. BonaRes consists of ten interdisciplinary research project consortia and the 'BonaRes - Centre for Soil Research'. BonaRes Data Centre is responsible for collecting all LTFE data and regarding metadata into an enterprise database upon higher level of security and visualization of the data and metadata through data portal. In the frame of the BonaRes project, we are compiling an overview of long-term field experiments in Germany that is based on a literature review, the results of the online survey and direct contacts with LTFE operators. Information about research topic, contact person, website, experiment setup and analyzed parameters are collected. Based on the collected LTFE data, an enterprise geodatabase is developed and a GIS-based web-information system about LTFE in Germany is also settled. Various aspects of the LTFE, like experiment type, land-use type, agricultural category and duration of experiment, are presented in thematic maps. This information system is dynamically linked to the database, which means changes in the data directly affect the presentation. An easy data searching option using LTFE name, -location or -operators and the dynamic layer selection ensure a user-friendly web application. Dispersion and visualization of the overlapping LTFE points on the overview map are also challenging and we make it automatized at very zoom level which is also a consistent part of this application. The application provides both, spatial location and meta-information of LTFEs, which is backed-up by an enterprise geodatabase, GIS server for hosting map services and Java script API for web application development.

In Interactive, Web-Based Approach to Metadata Authoring

NASA Technical Reports Server (NTRS)

Pollack, Janine; Wharton, Stephen W. (Technical Monitor)

2001-01-01

NASA's Global Change Master Directory (GCMD) serves a growing number of users by assisting the scientific community in the discovery of and linkage to Earth science data sets and related services. The GCMD holds over 8000 data set descriptions in Directory Interchange Format (DIF) and 200 data service descriptions in Service Entry Resource Format (SERF), encompassing the disciplines of geology, hydrology, oceanography, meteorology, and ecology. Data descriptions also contain geographic coverage information, thus allowing researchers to discover data pertaining to a particular geographic location, as well as subject of interest. The GCMD strives to be the preeminent data locator for world-wide directory level metadata. In this vein, scientists and data providers must have access to intuitive and efficient metadata authoring tools. Existing GCMD tools are not currently attracting. widespread usage. With usage being the prime indicator of utility, it has become apparent that current tools must be improved. As a result, the GCMD has released a new suite of web-based authoring tools that enable a user to create new data and service entries, as well as modify existing data entries. With these tools, a more interactive approach to metadata authoring is taken, as they feature a visual "checklist" of data/service fields that automatically update when a field is completed. In this way, the user can quickly gauge which of the required and optional fields have not been populated. With the release of these tools, the Earth science community will be further assisted in efficiently creating quality data and services metadata. Keywords: metadata, Earth science, metadata authoring tools

NCPP's Use of Standard Metadata to Promote Open and Transparent Climate Modeling

NASA Astrophysics Data System (ADS)

Treshansky, A.; Barsugli, J. J.; Guentchev, G.; Rood, R. B.; DeLuca, C.

2012-12-01

The National Climate Predictions and Projections (NCPP) Platform is developing comprehensive regional and local information about the evolving climate to inform decision making and adaptation planning. This includes both creating and providing tools to create metadata about the models and processes used to create its derived data products. NCPP is using the Common Information Model (CIM), an ontology developed by a broad set of international partners in climate research, as its metadata language. This use of a standard ensures interoperability within the climate community as well as permitting access to the ecosystem of tools and services emerging alongside the CIM. The CIM itself is divided into a general-purpose (UML & XML) schema which structures metadata documents, and a project or community-specific (XML) Controlled Vocabulary (CV) which constraints the content of metadata documents. NCPP has already modified the CIM Schema to accommodate downscaling models, simulations, and experiments. NCPP is currently developing a CV for use by the downscaling community. Incorporating downscaling into the CIM will lead to several benefits: easy access to the existing CIM Documents describing CMIP5 models and simulations that are being downscaled, access to software tools that have been developed in order to search, manipulate, and visualize CIM metadata, and coordination with national and international efforts such as ES-DOC that are working to make climate model descriptions and datasets interoperable. Providing detailed metadata descriptions which include the full provenance of derived data products will contribute to making that data (and, the models and processes which generated that data) more open and transparent to the user community.

Deletion of Rbpj from postnatal endothelium leads to abnormal arteriovenous shunting in mice

PubMed Central

Nielsen, Corinne M.; Cuervo, Henar; Ding, Vivianne W.; Kong, Yupeng; Huang, Eric J.; Wang, Rong A.

2014-01-01

Arteriovenous malformations (AVMs) are tortuous vessels characterized by arteriovenous (AV) shunts, which displace capillaries and shunt blood directly from artery to vein. Notch signaling regulates embryonic AV specification by promoting arterial, as opposed to venous, endothelial cell (EC) fate. To understand the essential role of endothelial Notch signaling in postnatal AV organization, we used inducible Cre-loxP recombination to delete Rbpj, a mediator of canonical Notch signaling, from postnatal ECs in mice. Deletion of endothelial Rbpj from birth resulted in features of AVMs by P14, including abnormal AV shunting and tortuous vessels in the brain, intestine and heart. We further analyzed brain AVMs, as they pose particular health risks. Consistent with AVM pathology, we found cerebral hemorrhage, hypoxia and necrosis, and neurological deficits. AV shunts originated from capillaries (and possibly venules), with the earliest detectable morphological abnormalities in AV connections by P8. Prior to AV shunt formation, alterations in EC gene expression were detected, including decreased Efnb2 and increased Pai1, which encodes a downstream effector of TGFβ signaling. After AV shunts had formed, whole-mount immunostaining showed decreased Efnb2 and increased Ephb4 expression within AV shunts, suggesting that ECs were reprogrammed from arterial to venous identity. Deletion of Rbpj from adult ECs led to tortuosities in gastrointestinal, uterine and skin vascular beds, but had mild effects in the brain. Our results demonstrate a temporal requirement for Rbpj in postnatal ECs to maintain proper artery, capillary and vein organization and to prevent abnormal AV shunting and AVM pathogenesis. PMID:25209249

Impact on cognitive functions following gamma knife radiosurgery for cerebral arteriovenous malformations

PubMed Central

Raghunath, A.; Bennett, Niranjana; Arimappamagan, Arivazhagan; Bhat, Dhananjaya I.; Srinivas, Dwarakanath; Thennarasu, K.; Jamuna, R.; Somanna, Sampath

2016-01-01

Background: Radiosurgery is an alternative to surgical resection of arteriovenous malformation (AVM). Very few studies have addressed the concern of radiation injury to the brain and its attendant adverse effects on cognitive function. Materials and Methods: This prospective study included all patients who underwent gamma knife radiosurgery (GKRS) at our institute for cerebral AVM between 2006 and December 2008 (n = 34). All patients underwent neuropsychological evaluation before the procedure. Neuropsychological evaluation was repeated in eighteen patients 2 years following GKRS. Clinical outcome, AVM obliteration, and factors influencing outcome were analyzed in these eighteen patients. Results: Before GKRS, more than 50% had significant impairment of neuropsychological functions compared to normal population norms. 66.6% achieved the excellent radiosurgical outcome. At 2 years follow-up, patients showed varied improvement in neuropsychological function in various categories. Pretherapeutic median value for percentage perseverative responses was 26.5 and at follow-up, it reduced to 18.2 (P = 0.039). Set shifting improved in 11 patients (61.1%), remained same in 5 patients (27.7%), and deteriorated in two patients (11.1%). Patients with a higher Spetzler-Martin grade AVM demonstrated a significantly more favorable shift in follow-up test values for set shifting function (P = 0.021). Patients with postradiation imaging changes had lesser tendency to improve in neuropsychological performance at follow-up. Conclusions: GKRS has no clinically harmful effect on cognitive and neuropsychological functioning in patients with brain AVM. On the contrary, there is an improvement in majority of patients at 2 years following radiosurgery when nidus is obliterated. PMID:26933340

Spatiotemporal Fractionation Schemes for Irradiating Large Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Bussière, Marc R.; Chapman, Paul H.

2016-07-01

Purpose: To optimally exploit fractionation effects in the context of radiosurgery treatments of large cerebral arteriovenous malformations (AVMs). In current practice, fractionated treatments divide the dose evenly into several fractions, which generally leads to low obliteration rates. In this work, we investigate the potential benefit of delivering distinct dose distributions in different fractions. Methods and Materials: Five patients with large cerebral AVMs were reviewed and replanned for intensity modulated arc therapy delivered with conventional photon beams. Treatment plans allowing for different dose distributions in all fractions were obtained by performing treatment plan optimization based on the cumulative biologically effective dosemore » delivered at the end of treatment. Results: We show that distinct treatment plans can be designed for different fractions, such that high single-fraction doses are delivered to complementary parts of the AVM. All plans create a similar dose bath in the surrounding normal brain and thereby exploit the fractionation effect. This partial hypofractionation in the AVM along with fractionation in normal brain achieves a net improvement of the therapeutic ratio. We show that a biological dose reduction of approximately 10% in the healthy brain can be achieved compared with reference treatment schedules that deliver the same dose distribution in all fractions. Conclusions: Boosting complementary parts of the target volume in different fractions may provide a therapeutic advantage in fractionated radiosurgery treatments of large cerebral AVMs. The strategy allows for a mean dose reduction in normal brain that may be valuable for a patient population with an otherwise normal life expectancy.« less

Successful Pregnancy with a Full-Term Vaginal Delivery One Year After n-Butyl Cyanoacrylate Embolization of a Uterine Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, Colleen C.; Kim, Hyun S.

Uterine arteriovenous malformation (AVM) causes significant morbidity with vaginal bleeding. Traditional therapy is a hysterectomy with no potential for future pregnancy. We present a case of successful superselective embolization of uterine AVM using n-butyl cyanoacrylate with subsequent normal term pregnancy and uncomplicated vaginal delivery in 1 year.

Iron deficiency, ischaemic strokes, and right-to-left shunts: From pulmonary arteriovenous malformations to patent foramen ovale?

PubMed Central

Shovlin, Claire L.

2014-01-01

Summary Has the recent identification of iron deficiency as a risk factor for ischaemic stroke in patients with pulmonary arteriovenous malformations (AVMs) unmasked a new paradigm for stroke/infarct pathogenesis? This commentary reviews evidence that spans associations between iron deficiency and ischaemic strokes, iron deficiency enhancement of platelet aggregation in response to serotonin/5HT, settings in which plasma 5HT is elevated, and clinical trial confirmation that 5HT receptor antagonists prevent ischaemic stroke. The critical leap which directs attention away from atherothrombotic events at the neurovascular wall is that ischaemic strokes due to pulmonary AVMs are attributable to compromised pulmonary capillary bed filtration of venous blood. Right-to-left shunting is continuous through pulmonary AVMs, but also occurs intermittently in approximately 30% of the general population with intracardiac shunts such as patent foramen ovale (PFO). The testable hypothesis presented is that paradoxical embolism of venous platelet-based aggregates may constitute part of the causal chain between iron deficiency and ischaemic stroke, not only in the rare disease state of pulmonary AVMs, but also in major subgroups of the general population. PMID:25343129

Expanding Access and Usage of NASA Near Real-Time Imagery and Data

NASA Astrophysics Data System (ADS)

Cechini, M.; Murphy, K. J.; Boller, R. A.; Schmaltz, J. E.; Thompson, C. K.; Huang, T.; McGann, J. M.; Ilavajhala, S.; Alarcon, C.; Roberts, J. T.

2013-12-01

In late 2009, the Land Atmosphere Near-real-time Capability for EOS (LANCE) was created to greatly expand the range of near real-time data products from a variety of Earth Observing System (EOS) instruments. Since that time, NASA's Earth Observing System Data and Information System (EOSDIS) developed the Global Imagery Browse Services (GIBS) to provide highly responsive, scalable, and expandable imagery services that distribute near real-time imagery in an intuitive and geo-referenced format. The GIBS imagery services provide access through standards-based protocols such as the Open Geospatial Consortium (OGC) Web Map Tile Service (WMTS) and standard mapping file formats such as the Keyhole Markup Language (KML). Leveraging these standard mechanisms opens NASA near real-time imagery to a broad landscape of mapping libraries supporting mobile applications. By easily integrating with mobile application development libraries, GIBS makes it possible for NASA imagery to become a reliable and valuable source for end-user applications. Recently, EOSDIS has taken steps to integrate near real-time metadata products into the EOS ClearingHOuse (ECHO) metadata repository. Registration of near real-time metadata allows for near real-time data discovery through ECHO clients. In kind with the near real-time data processing requirements, the ECHO ingest model allows for low-latency metadata insertion and updates. Combining with the ECHO repository, the fast visual access of GIBS imagery can now be linked directly back to the source data file(s). Through the use of discovery standards such as OpenSearch, desktop and mobile applications can connect users to more than just an image. As data services, such as OGC Web Coverage Service, become more prevalent within the EOSDIS system, applications may even be able to connect users from imagery to data values. In addition, the full resolution GIBS imagery provides visual context to other GIS data and tools. The NASA near real-time imagery covers a broad set of Earth science disciplines. By leveraging the ECHO and GIBS services, these data can become a visual context within which other GIS activities are performed. The focus of this presentation is to discuss the GIBS imagery and ECHO metadata services facilitating near real-time discovery and usage. Existing synergies and future possibilities will also be discussed. The NASA Worldview demonstration client will be used to show an existing application combining the ECHO and GIBS services.

The importance of metadata to assess information content in digital reconstructions of neuronal morphology.

PubMed

Parekh, Ruchi; Armañanzas, Rubén; Ascoli, Giorgio A

2015-04-01

Digital reconstructions of axonal and dendritic arbors provide a powerful representation of neuronal morphology in formats amenable to quantitative analysis, computational modeling, and data mining. Reconstructed files, however, require adequate metadata to identify the appropriate animal species, developmental stage, brain region, and neuron type. Moreover, experimental details about tissue processing, neurite visualization and microscopic imaging are essential to assess the information content of digital morphologies. Typical morphological reconstructions only partially capture the underlying biological reality. Tracings are often limited to certain domains (e.g., dendrites and not axons), may be incomplete due to tissue sectioning, imperfect staining, and limited imaging resolution, or can disregard aspects irrelevant to their specific scientific focus (such as branch thickness or depth). Gauging these factors is critical in subsequent data reuse and comparison. NeuroMorpho.Org is a central repository of reconstructions from many laboratories and experimental conditions. Here, we introduce substantial additions to the existing metadata annotation aimed to describe the completeness of the reconstructed neurons in NeuroMorpho.Org. These expanded metadata form a suitable basis for effective description of neuromorphological data.

Outcome after conservative management or intervention for unruptured brain arteriovenous malformations.

PubMed

Al-Shahi Salman, Rustam; White, Philip M; Counsell, Carl E; du Plessis, Johann; van Beijnum, Janneke; Josephson, Colin B; Wilkinson, Tim; Wedderburn, Catherine J; Chandy, Zoe; St George, E Jerome; Sellar, Robin J; Warlow, Charles P

Whether conservative management is superior to interventional treatment for unruptured brain arteriovenous malformations (bAVMs) is uncertain because of the shortage of long-term comparative data. To compare the long-term outcomes of conservative management vs intervention for unruptured bAVM. Population-based inception cohort study of 204 residents of Scotland aged 16 years or older who were first diagnosed as having an unruptured bAVM during 1999-2003 or 2006-2010 and followed up prospectively for 12 years. Conservative management (no intervention) vs intervention (any endovascular embolization, neurosurgical excision, or stereotactic radiosurgery alone or in combination). Cox regression analyses, with multivariable adjustment for prognostic factors and baseline imbalances if hazards were proportional, to compare rates of the primary outcome (death or sustained morbidity of any cause by Oxford Handicap Scale [OHS] score ≥2 for ≥2 successive years [0 = no symptoms and 6 = death]) and the secondary outcome (nonfatal symptomatic stroke or death due to bAVM, associated arterial aneurysm, or intervention). Of 204 patients, 103 underwent intervention. Those who underwent intervention were younger, more likely to have presented with seizure, and less likely to have large bAVMs than patients managed conservatively. During a median follow-up of 6.9 years (94% completeness), the rate of progression to the primary outcome was lower with conservative management during the first 4 years of follow-up (36 vs 39 events; 9.5 vs 9.8 per 100 person-years; adjusted hazard ratio, 0.59; 95% CI, 0.35-0.99), but rates were similar thereafter. The rate of the secondary outcome was lower with conservative management during 12 years of follow-up (14 vs 38 events; 1.6 vs 3.3 per 100 person-years; adjusted hazard ratio, 0.37; 95% CI, 0.19-0.72). Among patients aged 16 years or older diagnosed as having unruptured bAVM, use of conservative management compared with intervention was associated with better clinical outcomes for up to 12 years. Longer follow-up is required to understand whether this association persists.

New predictive model for microsurgical outcome of intracranial arteriovenous malformations: study protocol.

PubMed

Tong, Xianzeng; Wu, Jun; Cao, Yong; Zhao, Yuanli; Wang, Shuo

2017-01-27

Although microsurgical resection is currently the first-line treatment modality for arteriovenous malformations (AVMs), microsurgery of these lesions is complicated due to the fact that they are very heterogeneous vascular anomalies. The Spetzler-Martin grading system and the supplementary grading system have demonstrated excellent performances in predicting the risk of AVM surgery. However, there are currently no predictive models based on multimodal MRI techniques. The purpose of this study is to propose a predictive model based on multimodal MRI techniques to assess the microsurgical risk of intracranial AVMs. The study consists of 2 parts: the first part is to conduct a single-centre retrospective analysis of 201 eligible patients to create a predictive model of AVM surgery based on multimodal functional MRIs (fMRIs); the second part is to validate the efficacy of the predictive model in a prospective multicentre cohort study of 400 eligible patients. Patient characteristics, AVM features and multimodal fMRI data will be collected. The functional status at pretreatment and 6 months after surgery will be analysed using the modified Rankin Scale (mRS) score. The patients in each part of this study will be dichotomised into 2 groups: those with improved or unchanged functional status (a decreased or unchanged mRS 6 months after surgery) and those with worsened functional status (an increased mRS). The first part will determine the risk factors of worsened functional status after surgery and create a predictive model. The second part will validate the predictive model and then a new AVM grading system will be proposed. The study protocol and informed consent form have been reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital Affiliated to Capital Medical University (KY2016-031-01). The results of this study will be disseminated through printed media. NCT02868008. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Cerebral arteriovenous malformations and seizures: differential impact on the time to seizure-free state according to the treatment modalities.

PubMed

Hyun, Seung-Jae; Kong, Doo-Sik; Lee, Jung-Il; Kim, Jong-Soo; Hong, Seung-Chyul

2012-06-01

To determine the prognostic factors for the incidence and the outcome of seizure in patients with cerebral arteriovenous malformation (AVM) and to identify the time to seizure-free state according to the treatment modalities. Between 1995 and 2008, the multidisciplinary team at our institution treated 399 patients with cerebral AVMs. Treatment consisted of surgical resection, radiosurgery, and embolization, either alone or in combination. The median follow-up period was 6.0 years (range, 3.0-16.2 years). Eighty-six patients (21.5 %) experienced seizures before treatment. We investigated the variables associated with seizure incidence and seizure outcome and analyzed the outcomes of seizure among each treatment modality. After treatment, 60 (70 %) patients were seizure-free. Compared with 313 patients who did not experience seizures, we found that younger age (≤ 35 years), size ≥ 3 cm, and location of temporal lobe were associated with seizures (p < 0.05). Short seizure history, accompanying intracerebral hemorrhage, generalized tonic-clonic type seizure, deep-seated or infratentorial AVM, complete obliteration of AVM, and a favorable neurological outcome at 12 months were closely associated with Engel Class I outcomes (p < 0.05). Seizure-free outcomes after microsurgery, radiosurgery, or embolization were 78 %, 66 %, and 50 %, respectively. The overall annual bleeding rate was 1.0 % and 2.2 % in microsurgery-treated and radiosurgery-treated AVMs, respectively. In the surgery group, the median time to seizure-free status was 1.1 months (95 % CI, 0.7-1.2 months), whereas the radiosurgery group and embolization-alone group showed 20.5 months (95 % CI, 18.3-23.8 months), and 8.1 months (95 % CI, 6.0-13.5 months), respectively. A multidisciplinary team approach for cerebral AVMs achieved satisfactory seizure control results. Microsurgery led to the highest percentage of seizure-free outcomes and had the lowest annual bleeding rate, whereas radiosurgery had a higher bleeding rate. Median time to seizure-free status in surgically treated patients was shorter than in patients who underwent radiosurgical or endovascular treatment.

{Semantic metadata application for information resources systematization in water spectroscopy} A.Fazliev (1), A.Privezentsev (1), J.Tennyson (2) (1) Institute of Atmospheric Optics SB RAS, Tomsk, Russia, (2) University College London, London, UK (faz@iao

NASA Astrophysics Data System (ADS)

Fazliev, A.

2009-04-01

The information and knowledge layers of information-computational system for water spectroscopy are described. Semantic metadata for all the tasks of domain information model that are the basis of the layers have been studied. The principle of semantic metadata determination and mechanisms of the usage during information systematization in molecular spectroscopy has been revealed. The software developed for the work with semantic metadata is described as well. Formation of domain model in the framework of Semantic Web is based on the use of explicit specification of its conceptualization or, in other words, its ontologies. Formation of conceptualization for molecular spectroscopy was described in Refs. 1, 2. In these works two chains of task are selected for zeroth approximation for knowledge domain description. These are direct tasks chain and inverse tasks chain. Solution schemes of these tasks defined approximation of data layer for knowledge domain conceptualization. Spectroscopy tasks solutions properties lead to a step-by-step extension of molecular spectroscopy conceptualization. Information layer of information system corresponds to this extension. An advantage of molecular spectroscopy model designed in a form of tasks chain is actualized in the fact that one can explicitly define data and metadata at each step of solution of these molecular spectroscopy chain tasks. Metadata structure (tasks solutions properties) in knowledge domain also has form of a chain in which input data and metadata of the previous task become metadata of the following tasks. The term metadata is used in its narrow sense: metadata are the properties of spectroscopy tasks solutions. Semantic metadata represented with the help of OWL 3 are formed automatically and they are individuals of classes (A-box). Unification of T-box and A-box is an ontology that can be processed with the help of inference engine. In this work we analyzed the formation of individuals of molecular spectroscopy applied ontologies as well as the software used for their creation by means of OWL DL language. The results of this work are presented in a form of an information layer and a knowledge layer in W@DIS information system 4. 1 FORMATION OF INDIVIDUALS OF WATER SPECTROSCOPY APPLIED ONTOLOGY Applied tasks ontology contains explicit description of input an output data of physical tasks solved in two chains of molecular spectroscopy tasks. Besides physical concepts, related to spectroscopy tasks solutions, an information source, which is a key concept of knowledge domain information model, is also used. Each solution of knowledge domain task is linked to the information source which contains a reference on published task solution, molecule and task solution properties. Each information source allows us to identify a certain knowledge domain task solution contained in the information system. Water spectroscopy applied ontology classes are formed on the basis of molecular spectroscopy concepts taxonomy. They are defined by constrains on properties of the selected conceptualization. Extension of applied ontology in W@DIS information system is actualized according to two scenarios. Individuals (ontology facts or axioms) formation is actualized during the task solution upload in the information system. Ontology user operation that implies molecular spectroscopy taxonomy and individuals is performed solely by the user. For this purpose Protege ontology editor was used. For the formation, processing and visualization of knowledge domain tasks individuals a software was designed and implemented. Method of individual formation determines the sequence of steps of created ontology individuals' generation. Tasks solutions properties (metadata) have qualitative and quantitative values. Qualitative metadata are regarded as metadata describing qualitative side of a task such as solution method or other information that can be explicitly specified by object properties of OWL DL language. Quantitative metadata are metadata that describe quantitative properties of task solution such as minimal and maximal data value or other information that can be explicitly obtained by programmed algorithmic operations. These metadata are related to DatatypeProperty properties of OWL specification language Quantitative metadata can be obtained automatically during data upload into information system. Since ObjectProperty values are objects, processing of qualitative metadata requires logical constraints. In case of the task solved in W@DIS ICS qualitative metadata can be formed automatically (for example in spectral functions calculation task). The used methods of translation of qualitative metadata into quantitative is characterized as roughened representation of knowledge in knowledge domain. The existence of two ways of data obtainment is a key moment in the formation of applied ontology of molecular spectroscopy task. experimental method (metadata for experimental data contain description of equipment, experiment conditions and so on) on the initial stage and inverse task solution on the following stages; calculation method (metadata for calculation data are closely related to the metadata used for the description of physical and mathematical models of molecular spectroscopy) 2 SOFTWARE FOR ONTOLOGY OPERATION Data collection in water spectroscopy information system is organized in a form of workflow that contains such operations as information source creation, entry of bibliographic data on publications, formation of uploaded data schema an so on. Metadata are generated in information source as well. Two methods are used for their formation: automatic metadata generation and manual metadata generation (performed by user). Software implementation of support of actions related to metadata formation is performed by META+ module. Functions of META+ module can be divided into two groups. The first groups contains the functions necessary to software developer while the second one the functions necessary to a user of the information system. META+ module functions necessary to the developer are: 1. creation of taxonomy (T-boxes) of applied ontology classes of knowledge domain tasks; 2. creation of instances of task classes; 3. creation of data schemes of tasks in a form of an XML-pattern and based on XML-syntax. XML-pattern is developed for instances generator and created according to certain rules imposed on software generator implementation. 4. implementation of metadata values calculation algorithms; 5. creation of a request interface and additional knowledge processing function for the solution of these task; 6. unification of the created functions and interfaces into one information system The following sequence is universal for the generation of task classes' individuals that form chains. Special interfaces for user operations management are designed for software developer in META+ module. There are means for qualitative metadata values updating during data reuploading to information source. The list of functions necessary to end user contains: - data sets visualization and editing, taking into account their metadata, e.g.: display of unique number of bands in transitions for a certain data source; - export of OWL/RDF models from information system to the environment in XML-syntax; - visualization of instances of classes of applied ontology tasks on molecular spectroscopy; - import of OWL/RDF models into the information system and their integration with domain vocabulary; - formation of additional knowledge of knowledge domain for the construction of ontological instances of task classes using GTML-formats and their processing; - formation of additional knowledge in knowledge domain for the construction of instances of task classes, using software algorithm for data sets processing; - function of semantic search implementation using an interface that formulates questions in a form of related triplets in order for getting an adequate answer. 3 STRUCTURE OF META+ MODULE META+ software module that provides the above functions contains the following components: - a knowledge base that stores semantic metadata and taxonomies of information system; - software libraries POWL and RAP 5 created by third-party developer and providing access to ontological storage; - function classes and libraries that form the core of the module and perform the tasks of formation, storage and visualization of classes instances; - configuration files and module patterns that allow one to adjust and organize operation of different functional blocks; META+ module also contains scripts and patterns implemented according to the rules of W@DIS information system development environment. - scripts for interaction with environment by means of the software core of information system. These scripts provide organizing web-oriented interactive communication; - patterns for the formation of functionality visualization realized by the scripts Software core of scientific information-computational system W@DIS is created with the help of MVC (Model - View - Controller) design pattern that allows us to separate logic of application from its representation. It realizes the interaction of three logical components, actualizing interactivity with the environment via Web and performing its preprocessing. Functions of «Controller» logical component are realized with the help of scripts designed according to the rules imposed by software core of the information system. Each script represents a definite object-oriented class with obligatory class method of script initiation called "start". Functions of actualization of domain application operation results representation (i.e. "View" component) are sets of HTML-patterns that allow one to visualize the results of domain applications operation with the help of additional constructions processed by software core of the system. Besides the interaction with the software core of the scientific information system this module also deals with configuration files of software core and its database. Such organization of work provides closer integration with software core and deeper and more adequate connection in operating system support. 4 CONCLUSION In this work the problems of semantic metadata creation in information system oriented on information representation in the area of molecular spectroscopy have been discussed. The described method of semantic metadata and functions formation as well as realization and structure of META+ module have been described. Architecture of META+ module is closely related to the existing software of "Molecular spectroscopy" scientific information system. Realization of the module is performed with the use of modern approaches to Web-oriented applications development. It uses the existing applied interfaces. The developed software allows us to: - perform automatic metadata annotation of calculated tasks solutions directly in the information system; - perform automatic annotation of metadata on the solution of tasks on task solution results uploading outside the information system forming an instance of the solved task on the basis of entry data; - use ontological instances of task solution for identification of data in information tasks of viewing, comparison and search solved by information system; - export applied tasks ontologies for the operation with them by external means; - solve the task of semantic search according to the pattern and using question-answer type interface. 5 ACKNOWLEDGEMENT The authors are grateful to RFBR for the financial support of development of distributed information system for molecular spectroscopy. REFERENCES A.D.Bykov, A.Z. Fazliev, N.N.Filippov, A.V. Kozodoev, A.I.Privezentsev, L.N.Sinitsa, M.V.Tonkov and M.Yu.Tretyakov, Distributed information system on atmospheric spectroscopy // Geophysical Research Abstracts, SRef-ID: 1607-7962/gra/EGU2007-A-01906, 2007, v. 9, p. 01906. A.I.Prevezentsev, A.Z. Fazliev Applied task ontology for molecular spectroscopy information resources systematization. The Proceedings of 9th Russian scientific conference "Electronic libraries: advanced methods and technologies, electronic collections" - RCDL'2007, Pereslavl Zalesskii, 2007, part.1, 2007, P.201-210. OWL Web Ontology Language Semantics and Abstract Syntax, W3C Recommendation 10 February 2004, http://www.w3.org/TR/2004/REC-owl-semantics-20040210/ W@DIS information system, http://wadis.saga.iao.ru RAP library, http://www4.wiwiss.fu-berlin.de/bizer/rdfapi/.

Quality Metadata Management for Geospatial Scientific Workflows: from Retrieving to Assessing with Online Tools

NASA Astrophysics Data System (ADS)

Leibovici, D. G.; Pourabdollah, A.; Jackson, M.

2011-12-01

Experts and decision-makers use or develop models to monitor global and local changes of the environment. Their activities require the combination of data and processing services in a flow of operations and spatial data computations: a geospatial scientific workflow. The seamless ability to generate, re-use and modify a geospatial scientific workflow is an important requirement but the quality of outcomes is equally much important [1]. Metadata information attached to the data and processes, and particularly their quality, is essential to assess the reliability of the scientific model that represents a workflow [2]. Managing tools, dealing with qualitative and quantitative metadata measures of the quality associated with a workflow, are, therefore, required for the modellers. To ensure interoperability, ISO and OGC standards [3] are to be adopted, allowing for example one to define metadata profiles and to retrieve them via web service interfaces. However these standards need a few extensions when looking at workflows, particularly in the context of geoprocesses metadata. We propose to fill this gap (i) at first through the provision of a metadata profile for the quality of processes, and (ii) through providing a framework, based on XPDL [4], to manage the quality information. Web Processing Services are used to implement a range of metadata analyses on the workflow in order to evaluate and present quality information at different levels of the workflow. This generates the metadata quality, stored in the XPDL file. The focus is (a) on the visual representations of the quality, summarizing the retrieved quality information either from the standardized metadata profiles of the components or from non-standard quality information e.g., Web 2.0 information, and (b) on the estimated qualities of the outputs derived from meta-propagation of uncertainties (a principle that we have introduced [5]). An a priori validation of the future decision-making supported by the outputs of the workflow once run, is then provided using the meta-propagated qualities, obtained without running the workflow [6], together with the visualization pointing out the need to improve the workflow with better data or better processes on the workflow graph itself. [1] Leibovici, DG, Hobona, G Stock, K Jackson, M (2009) Qualifying geospatial workfow models for adaptive controlled validity and accuracy. In: IEEE 17th GeoInformatics, 1-5 [2] Leibovici, DG, Pourabdollah, A (2010a) Workflow Uncertainty using a Metamodel Framework and Metadata for Data and Processes. OGC TC/PC Meetings, September 2010, Toulouse, France [3] OGC (2011) www.opengeospatial.org [4] XPDL (2008) Workflow Process Definition Interface - XML Process Definition Language.Workflow Management Coalition, Document WfMC-TC-1025, 2008 [5] Leibovici, DG Pourabdollah, A Jackson, M (2011) Meta-propagation of Uncertainties for Scientific Workflow Management in Interoperable Spatial Data Infrastructures. In: Proceedings of the European Geosciences Union (EGU2011), April 2011, Austria [6] Pourabdollah, A Leibovici, DG Jackson, M (2011) MetaPunT: an Open Source tool for Meta-Propagation of uncerTainties in Geospatial Processing. In: Proceedings of OSGIS2011, June 2011, Nottingham, UK

Quality of life and disability 12 months after surgery vs. conservative management for unruptured brain arteriovenous malformations: Scottish population-based and Australian hospital-based studies.

PubMed

O'Donnell, Joan Margaret; Al-Shahi Salman, Rustam; Manuguerra, Maurizio; Assaad, Nazih; Morgan, Michael Kerin

2018-03-01

Few data are available on disability and quality of life (QOL) after surgery versus conservative management for unruptured brain arteriovenous malformations (uAVMs). The aim of this study was to test the hypothesis that QOL and disability are worse after surgery ± preoperative embolisation for uAVM compared with conservative management. We included consecutive patients diagnosed with uAVM from a prospective population-based study in Scotland (1999-2003; 2006-2010) and a prospective hospital-based series in Australia (2011-2015). We assessed outcomes on the modified Rankin Scale (mRS) and the Short Form (SF)-36 at ~ 12 months after surgery or conservative treatment and compared these groups using continuous ordinal regression in the two cohorts separately. Surgery was performed for 29% of all uAVM cases diagnosed in Scotland and 84% of all uAVM referred in Australia. There was no statistically significant difference between surgery and conservative management at 12 months among 79 patients in Scotland (mean SF-36 Physical Component Score (PCS) 39 [SD 14] vs. 39 [SD 13]; mean SF-36 Mental Component Score (MCS) 38 [SD 14] vs. 39 [SD 14]; mRS > 1, 24 vs. 9%), nor among 37 patients in Australia (PCS 51 [SD 10] vs. 49 [SD 6]; MCS 48 [SD 12] vs. 49 [SD 10]; mRS > 1, 19 vs. 30%). In the Australian series, there was no statistically significant change in the MCS and PCS between baseline before surgery or conservative management and 12 months. We did not find a statistically significant difference between surgery ± preoperative embolisation and conservative management in disability or QOL at 12 months.

Untreated brain arteriovenous malformation

PubMed Central

Al-Shahi Salman, Rustam; McCulloch, Charles E.; Stapf, Christian; Young, William L.

2014-01-01

Objective: To identify risk factors for intracranial hemorrhage in the natural history course of brain arteriovenous malformations (AVMs) using individual patient data meta-analysis of 4 existing cohorts. Methods: We harmonized data from Kaiser Permanente of Northern California (n = 856), University of California San Francisco (n = 787), Columbia University (n = 672), and the Scottish Intracranial Vascular Malformation Study (n = 210). We censored patients at first treatment, death, last visit, or 10-year follow-up, and performed stratified Cox regression analysis of time-to-hemorrhage after evaluating hemorrhagic presentation, sex, age at diagnosis, deep venous drainage, and AVM size as predictors. Multiple imputation was performed to assess impact of missing data. Results: A total of 141 hemorrhage events occurred during 6,074 patient-years of follow-up (annual rate of 2.3%, 95% confidence interval [CI] 2.0%–2.7%), higher for ruptured (4.8%, 3.9%–5.9%) than unruptured (1.3%, 1.0%–1.7%) AVMs at presentation. Hemorrhagic presentation (hazard ratio 3.86, 95% CI 2.42–6.14) and increasing age (1.34 per decade, 1.17–1.53) independently predicted hemorrhage and remained significant predictors in the imputed dataset. Female sex (1.49, 95% CI 0.96–2.30) and exclusively deep venous drainage (1.60, 0.95–2.68, p = 0.02 in imputed dataset) may be additional predictors. AVM size was not associated with intracerebral hemorrhage in multivariable models (p > 0.5). Conclusion: This large, individual patient data meta-analysis identified hemorrhagic presentation and increasing age as independent predictors of hemorrhage during follow-up. Additional AVM cohort data may further improve precision of estimates, identify new risk factors, and allow validation of prediction models. PMID:25015366

Onyx in Brain Arteriovenous Malformation Embolisation.

PubMed

Hashim, Hilwati; Muda, A Sobri; Abdul Aziz, Aida; Abdul Hamid, Zuhanis

2016-07-01

Embolisation has long been used as an adjunct to surgical resection in the treatment of brain arteriovenous malformation (bAVM). The most commonly used embolic material, n-butylcyanoacrylate glue, requires experience and skill to handle its quick and unpredictable flow and polymerisation. A new liquid embolic agent, ethylene vinyl alcohol copolymer (Onyx), is less adhesive and polymerises slowly, which provides better control for radiologists performing embolisation. To report our experience in embolisation using Onyx alone or in combination with histoacryl for bAVM embolisation in our tertiary referral centre. We retrospectively reviewed the anatomy, technical conditions, complications and clinical outcome of all bAVM patients embolised at our centre using Onyx alone or in combination with n-butylcyanoacrylate glue. Between 2010 and 2013, 13 patients [6 (46.2%) male; 7 (53.8%) female; aged, 14-57 years] were included, and a total of 31 embolisations were performed. Clinical presentation included hemorrhage [9 (69.2%)], seizures [2 (15.4%)], and headache [2 (15.4%)]. Most AVMs were located in the brain hemispheres [12 (92.3%)] and measured <3 cm [7 (53.8%]. Complete occlusion of the AVM was obtained in 2 (15.4%) patients; 11 (84.6%) patients had partial occlusion [6 (54.5%) had <50% nidus occlusion]. Complications occurred in four procedures involving 3 patients (morbidity, 23.1%). This resulted in the death of 1 patient (mortality, 7.7%) and complete recovery with no disability in 2 patients. The total nidal occlusion achieved herein is comparable to other similar studies. Our morbidity and mortality were higher compared to other studies which may be attributed to the small number of patients. More data is being collected which may better reflect on our experience.

Impact of Onyx Embolization on Radiosurgical Management of Cerebral Arteriovenous Malformations: Treatment and Outcome.

PubMed

Strauss, Ido; Haim, Oz; Umansky, Daniel; Corn, Benjamin W; Frolov, Vladimir; Shtraus, Natan; Maimon, Shimon; Kanner, Andrew A

2017-12-01

Stereotactic radiosurgery (SRS) is a well-established treatment modality for cerebral arteriovenous malformations (AVMs). The main limiting factor in the radiosurgical treatment of AVMs is the volume of the nidus, with high-grade lesions often requiring combined treatment to reduce the SRS target volume. To overcome this limitation, we have been using a combined treatment approach consisting of endovascular embolization with Onyx followed by SRS. To evaluate our clinical experience for safety and feasibility of this multimodality treatment approach. This is a retrospective review of all adult patients with cerebral AVMs who received SRS treatment to their AVM after endovascular embolization with Onyx between June 2007 and June 2014. Thirty-five consecutive patients were identified. The mean follow-up period was 52.4 ± 22.6 months (range 18-97 months). We confirmed 18 (51.4%) complete nidus closures at a median time of 49.5 months (range 6.5-81 months) from SRS. High-resolution Magnetic resonance imaging/magnetic resonance angiography was performed routinely in all patients until closure of the nidus. Digital subtraction angiography was performed to confirm complete obliteration in 5 of the patients (28%); 13 patients are either planned for digital subtraction angiography or have refused it. In 6 patients (17%) a significant flow reduction was noted after a mean of 32 ± 16 months. No significant improvement was observed in 9 patients (26%) during the follow-up period. Two patients were lost to follow-up. The multimodality treatment of cerebral AVMs using embolization with Onyx followed by SRS is feasible and safe. The use of Onyx significantly reduced the SRS treatment target volume. Copyright © 2017 Elsevier Inc. All rights reserved.

The Retrograde Transvenous Push-Through Method: A Novel Treatment of Peripheral Arteriovenous Malformations with Dominant Venous Outflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohlgemuth, Walter A., E-mail: walter.wohlgemuth@ukr.de; Müller-Wille, René, E-mail: Rene.Mueller-Wille@ukr.de; Teusch, Veronika I., E-mail: Veronika.Teusch@gmx.de

2015-06-15

PurposeTo evaluate the efficacy and safety of a novel retrograde transvenous embolization technique of peripheral arteriovenous malformations (AVMs) using Onyx.Materials and MethodsWe conducted a retrospective analysis of all patients who underwent transvenous retrograde Onyx embolization of peripheral AVMs with dominant venous outflow over a 29-month period. The embolization is aimed at retrograde filling of the nidus after building a solid plug in the dominant venous outflow (push-through). Classification, clinical signs, technical aspects, clinical and technical success rates, and complications were recorded. Short-term outcome was assessed.Results11 Symptomatic patients (8 female; mean age 31.4 years) were treated at our Vascular Anomalies Center withmore » this method between January 2012 and May 2014. The AVMs were located on the upper extremity (n = 3), pelvis (n = 2), buttock (n = 2), and lower extremity (n = 4). Retrograde embolization was successfully carried out after preparatory transarterial-flow reduction in eight cases (73 %) and venous-flow reduction with Amplatzer Vascular Plugs in four cases (36 %). Complete devascularization (n = 10; 91 %) or 95 % devascularization (n = 1; 9 %) led to complete resolution (n = 8; 73 %) or improvement of clinical symptoms (n = 3; 27 %). One minor complication occurred (pain and swelling). During a mean follow-up time of 8 months, one clinically asymptomatic recurrence of AVM was detected.ConclusionInitial results suggest that retrograde transvenous Onyx embolization of peripheral AVMs with dominant venous outflow is a safe and effective novel technique with a low complication rate.« less

The Treatment of Brain Arteriovenous Malformation Study (TOBAS): A preliminary inter- and intra-rater agreement study on patient management.

PubMed

Fahed, Robert; Batista, André L; Darsaut, Tim E; Gentric, Jean-Christophe; Ducroux, Célina; Chaalala, Chiraz; Roberge, David; Bojanowski, Michel W; Weill, Alain; Roy, Daniel; Magro, Elsa; Raymond, Jean

2017-07-01

The best management of brain arteriovenous malformation (bAVM) patients remains unknown. Randomized allocation may be more readily accepted when there is uncertainty and disagreement regarding the management of potential participants. In planning for a trial, we aimed to assess variability and agreement among physicians managing bAVM patients. A portfolio composed of 35 patients was sent to 47 clinicians of various specialties managing bAVM patients. For each patient, physicians were asked their best management decision (surgery/embolization/radiosurgery/conservative), their confidence level, and whether they would include the patient in a randomized trial comparing conservative and curative management. Seven physicians, who had access to all images of each patient, independently responded twice, to assess inter and intra-rater agreement using kappa statistics. The inter-rater agreement (30 raters, including 16 neuroradiologists) for best management decision was only "fair" (κ [95%CI]=0.210[0.157; 0.295]). Agreement remained below 'substantial' (κ<.6) between physicians of the same specialty, and when no distinctions were made between various treatments (when responses were dichotomized as conservative versus curative). With access to all images the inter-rater agreement remained fair. The intra-rater agreement reached "substantial" only for the dichotomized decisions. Responding clinicians were willing to include 54.4% of patients (mainly unruptured bAVMs) in a randomized trial. There is a lack of agreement among clinicians involved in the management of bAVM patients. In this study a substantial proportion of clinicians were willing to offer randomized allocation of management options to a substantial number of patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

RASA1 analysis guides management in a family with capillary malformation-arteriovenous malformation

PubMed Central

Flore, Leigh Anne; Leon, Eyby; Maher, Tom A.; Milunsky, Jeff M.

2012-01-01

Capillary malformation-arteriovenous malformation (CM-AVM; MIM 60354) is an autosomal dominant disorder characterized by multifocal cutaneous capillary malformations, often in association with fast-flow vascular lesions, which may be cutaneous, subcutaneous, intramuscular, intraosseus, or cerebral arteriovenous malformations or arteriovenous fistulas. CM-AVM results from heterozygous mutations in the RASA1 gene. Capillary malformations of the skin are common, and clinical examination alone may not be able to definitively diagnose-or exclude- CM-AVM. We report a family in which the proband was initially referred for a genetic evaluation in the neonatal period because of the presence of a cardiac murmur and minor dysmorphic features. Both he and his mother were noted to have multiple capillary malformations on the face, head, and extremities. Echocardiography revealed dilated head and neck vessels and magnetic resonance imaging and angiography of the brain revealed a large infratentorial arteriovenous fistula, for which he has had two embolization procedures. RASA1 sequence analysis revealed a heterozygous mutation, confirming his diagnosis of CM-AVM. We established targeted mutation analysis for the proband's mother and sister, the latter of whom is a healthy 3-year-old whose only cutaneous finding is a facial capillary malformation. This revealed that the proband's mother is also heterozygous for the RASA1 mutation, but his sister is negative. Consequently, his mother will undergo magnetic resonance imaging and angiography screening for intracranial and spinal fast-flow lesions, while his sister will require no imaging or serial evaluations. Targeted mutation analysis has been offered to additional maternal family members. This case illustrates the benefit of molecular testing in diagnosis and making screening recommendations for families with CM-AVM. PMID:27625812

RASA1 analysis guides management in a family with capillary malformation-arteriovenous malformation.

PubMed

Flore, Leigh Anne; Leon, Eyby; Maher, Tom A; Milunsky, Jeff M

2012-06-01

Capillary malformation-arteriovenous malformation (CM-AVM; MIM 60354) is an autosomal dominant disorder characterized by multifocal cutaneous capillary malformations, often in association with fast-flow vascular lesions, which may be cutaneous, subcutaneous, intramuscular, intraosseus, or cerebral arteriovenous malformations or arteriovenous fistulas. CM-AVM results from heterozygous mutations in the RASA1 gene. Capillary malformations of the skin are common, and clinical examination alone may not be able to definitively diagnose-or exclude- CM-AVM. We report a family in which the proband was initially referred for a genetic evaluation in the neonatal period because of the presence of a cardiac murmur and minor dysmorphic features. Both he and his mother were noted to have multiple capillary malformations on the face, head, and extremities. Echocardiography revealed dilated head and neck vessels and magnetic resonance imaging and angiography of the brain revealed a large infratentorial arteriovenous fistula, for which he has had two embolization procedures. RASA1 sequence analysis revealed a heterozygous mutation, confirming his diagnosis of CM-AVM. We established targeted mutation analysis for the proband's mother and sister, the latter of whom is a healthy 3-year-old whose only cutaneous finding is a facial capillary malformation. This revealed that the proband's mother is also heterozygous for the RASA1 mutation, but his sister is negative. Consequently, his mother will undergo magnetic resonance imaging and angiography screening for intracranial and spinal fast-flow lesions, while his sister will require no imaging or serial evaluations. Targeted mutation analysis has been offered to additional maternal family members. This case illustrates the benefit of molecular testing in diagnosis and making screening recommendations for families with CM-AVM.

Curative transvenous embolization for ruptured brain arteriovenous malformations: a single center experience from China.

PubMed

He, Yingkun; Bai, Weixing; Li, Tianxiao; Hui, Ferdinand K; He, Yanyan; Xu, Bin

2018-05-09

To evaluate the feasibility and safety of transvenous embolization treatment for brain arteriovenous malformations (bAVM). Between November 2016 and August 2017, a transvenous endovascular embolization protocol was implemented at the Henan Provincial People's Hospital for consecutive patients with ruptured bAVM. Therapeutic decision making was based on Spetzler-Martin grades, bAVM location, pattern of venous drainage, and angioarchitecture. And the transvenous embolization procedure was combined with transarterial support. Complete angiographic obliteration of the nidus was the objective of treatment. Among the 10 patients with ruptured bAVM, 8 were males. The Spetzler-Martin grades before the transvenous embolization session were IV for 3 of the 10 patients, III for 5 patients, II for 1 patient, and I for 1 patient. The preprocedural modified Rankin scale score (mRS) was 0-2 for 6 of the 10 patients, and 5 of 10 patients also had deep venous drainage. Arterial blood pressure control management and venous pressure cooker technique were used in all 10 patients; 9 patients had immediate angiographic occlusion, and 2 patients were found with a ventricular hemorrhage, which did not cause any disability after medical treatment. Seven patients underwent angiography 3 to 5 months after operation and complete obliteration of the nidus conformed. The median clinical follow-up for all 10 patients was 8 months (range 3-12), epilepsy occurred in one patient 3 months after the procedure, and the mRS scores of all patients were ≤1. Transvenous embolization of bAVM is feasible and may improve the cure rate. However, the safety and long-term effects need further validation. Copyright © 2018 Elsevier Inc. All rights reserved.

Linear Accelerator-Based Radiosurgery Alone for Arteriovenous Malformation: More Than 12 Years of Observation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Takayuki, E-mail: takayuki@nagasaki-u.ac.jp; Kamada, Kensaku; Izumo, Tsuyoshi

Purpose: Although radiosurgery is an accepted treatment method for intracranial arteriovenous malformations (AVMs), its long-term therapeutic effects have not been sufficiently evaluated, and many reports of long-term observations are from gamma-knife facilities. Furthermore, there are few reported results of treatment using only linear accelerator (LINAC)-based radiosurgery (LBRS). Methods and Materials: Over a period of more than 12 years, we followed the long-term results of LBRS treatment performed in 51 AVM patients. Results: The actuarial obliteration rates, after a single radiosurgery session, at 3, 5, 10, and 15 years were 46.9%, 54.0%, 64.4%, and 68.0%, respectively; when subsequent radiosurgeries were included, themore » rates were 46.9%, 61.3%, 74.2%, and 90.3%, respectively. Obliteration rates were significantly related to target volumes ≥4 cm{sup 3}, marginal doses ≥12 Gy, Spetzler-Martin grades (1 vs other), and AVM scores ≥1.5; multivariate analyses revealed a significant difference for target volumes ≥4 cm{sup 3}. The postprocedural actuarial symptomatic radiation injury rates, after a single radiation surgery session, at 5, 10, and 15 years were 12.3%, 16.8%, and 19.1%, respectively. Volumes ≥4 cm{sup 3}, location (lobular or other), AVM scores ≥1.5, and the number of radiosurgery were related to radiation injury incidence; multivariate analyses revealed significant differences associated with volumes ≥4 cm{sup 3} and location (lobular or other). Conclusions: Positive results can be obtained with LBRS when performed with a target volume ≤4 cm{sup 3}, an AVM score ≤1.5, and ≥12 Gy radiation. Bleeding and radiation injuries may appear even 10 years after treatment, necessitating long-term observation.« less

Use of ethylene-vinyl alcohol copolymer as a liquid embolic agent to treat a peripheral arteriovenous malformation in a dog

PubMed Central

Culp, William T. N.; Glaiberman, Craig B.; Pollard, Rachel E.; Wisner, Erik R.

2015-01-01

Case Description An 11-year-old castrated male Tibetan Mastiff was evaluated because of a visibly enlarged blood vessel and progressively worsening swelling of the right hind limb. Clinical Findings On physical examination, the right hind limb was markedly larger than the left hind limb and the dog was minimally weight bearing on the affected limb. A bruit was auscultated over the affected region. Ultrasonography of the tarsal region of the right hind limb revealed an artery with turbulent flow that communicated with venous drainage. A CT scan confirmed the presence of an arteriovenous malformation (AVM). Treatment and Outcome Embolization of the AVM with a liquid embolic agent (ethylene-vinyl alcohol copolymer dissolved in dimethyl sulfoxide) was elected. An arteriogram was performed prior to treatment and delineated the vessels that were targeted for embolization. The embolic agent was infused into the AVM, and a postinjection arteriogram confirmed complete occlusion of the AVM nidus and normal arterial flow to the paw with subsequent normal venous drainage. The circumference of the abnormal paw was 51 cm before the procedure and 22.9 cm at 4 weeks after the procedure. Additionally, the gait of the dog dramatically improved. No complications associated with the procedure developed. Clinical Relevance Peripheral AVMs in dogs are uncommon, and described treatment options are limited and generally associated with serious morbidity. A liquid embolic agent, ethylene-vinyl alcohol copolymer dissolved in dimethyl sulfoxide, was successfully administered in this case, and no morbidity was observed secondary to the procedure. Clinical success was characterized by substantial improvement in limb swelling and marked improvement in the gait of the dog. PMID:24984133

Proposal for a New Prognostic Score for Linac-Based Radiosurgery in Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milker-Zabel, Stefanie, E-mail: Stefanie_Milker-Zabel@med.uni-heidelberg.de; Kopp-Schneider, Annette; Wiesbauer, Hannah

2012-06-01

Purpose: We evaluate patient-, angioma-, and treatment-specific factors for successful obliteration of cerebral arteriovenous malformations (AVM) to develop a new appropriate score to predict patient outcome after linac-based radiosurgery (RS). Methods and Materials: This analysis in based on 293 patients with cerebral AVM. Mean age at treatment was 38.8 years (4-73 years). AVM classification according Spetzler-Martin was 55 patients Grade I (20.5%), 114 Grade II (42.5%), 79 Grade III (29.5%), 19 Grade IV (7.1%), and 1 Grade V (0.4%). Median maximum AVM diameter was 3.0 cm (range, 0.3-10 cm). Median dose prescribed to the 80% isodose was 18 Gy (range,more » 12-22 Gy). Eighty-five patients (29.1%) had prior partial embolization; 141 patients (51.9%) experienced intracranial hemorrhage before RS. Median follow-up was 4.2 years. Results: Age at treatment, maximum diameter, nidus volume, and applied dose were significant factors for successful obliteration. Under presumption of proportional hazard in the dose range between 12 and 22 Gy/80% isodose, an increase of obliteration rate of approximately 25% per Gy was seen. On the basis of multivariate analysis, a prediction score was calculated including AVM maximum diameter and age at treatment. The prediction error up to the time point 8 years was 0.173 for the Heidelberg score compared with the Kaplan-Meier value of 0.192. An increase of the score of 1 point results in a decrease of obliteration chance by a factor of 0.447. Conclusion: The proposed score is linac-based radiosurgery-specific and easy to handle to predict patient outcome. Further validation on an independent patient cohort is necessary.« less

Measurement of velocities with an acoustic velocity meter, one side-looking and two upward-looking acoustic Doppler current profilers in the Chicago Sanitary and Ship Canal, Romeoville, Illinois

USGS Publications Warehouse

Oberg, Kevin A.; Duncker, James J.

1999-01-01

In 1998, a prototype 300 kHz, side-looking Acoustic Doppler Current Profiler (ADCP) was deployed in the Chicago Sanitary and Ship Canal (CSSC) at Romeoville, Illinois. Additionally, two upward-looking ADCP's were deployed in the same acoustic path as the side-looking ADCP and in the reach defined by the upstream and downstream acoustic velocity meter (AVM) paths. All three ADCP's were synchronized to the AVM clock at the gaging station so that data were sampled simultaneously. The three ADCP's were deployed for six weeks measuring flow velocities from 0.0 to 2.5 ft/s. Velocities measured by each ADCP were compared to AVM path velocities and to velocities measured by the other ADCP's.

[Radiosurgical treatment of minor intracranial arteriovenous malformations by using a linear accelerator].

PubMed

Betti, O O; Munari, C

1992-01-01

This study deals with 43 patients with cerebral arteriovenous malformations (AVMs) of a maximum of 20 mm in diameter. All of them were radiosurgically treated with a linear accelerator in stereotatic conditions (UMIC). The delivered doses vary from 20 gys to 50 gys. Thirty-seven were controlled angiographically and 35 of them showed the disappearence of the AVM. Different parameters can modify the results: delivered dose, the size and shape of the lesion, target-volume, peripheral lesion isodosis (75%), location, underestimation of the size or dose. These results show that small lesions are best to treat than larger ones, particularly because their volume enables us to encompass them more easily. The uniformity of this series is related to the homogenous size of the treated AVMs, thus avoiding the discussion of global, unclear, results.

Progressive regression of intracranial arteriovenous malformations after Onyx embolization.

PubMed

Kocur, Damian; Przybyłko, Nikodem; Hofman, Mariusz; Jamróz, Tomasz; Doleżych, Hanna; Baron, Jan; Kwiek, Stanisław

Progressive regression of cerebral arteriovenous malformations (AVMs) is a rare phenomenon that may occur spontaneously or after previous surgical or endovascular incomplete obliteration. We present two cases of AVMs occluded partially with Onyx followed by the unexpected cure of the lesions with the angiographic evidences as well as multiannual follow-up. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Site comparison for optical visibility statistics in southern California

NASA Technical Reports Server (NTRS)

Cowles, K.

1991-01-01

Negotiations are under way to locate an atmospheric visibility monitoring (AVM) observatory at Mount Lemmon, just north of Tucson, Arizona. Two more observatories will be located in the southwestern U.S. The observatories are being employed to improve a weather model for deep-space-to-ground optical communications. This article explains the factors considered in choosing a location and recommends Table Mountain Observatory as the location for another AVM facility.

Accuracy of MRI volume measurements of breast lesions: comparison between automated, semiautomated and manual assessment.

PubMed

Rominger, Marga B; Fournell, Daphne; Nadar, Beenarose Thanka; Behrens, Sarah N M; Figiel, Jens H; Keil, Boris; Heverhagen, Johannes T

2009-05-01

The aim of this study was to investigate the efficacy of a dedicated software tool for automated and semiautomated volume measurement in contrast-enhanced (CE) magnetic resonance mammography (MRM). Ninety-six breast lesions with histopathological workup (27 benign, 69 malignant) were re-evaluated by different volume measurement techniques. Volumes of all lesions were extracted automatically (AVM) and semiautomatically (SAVM) from CE 3D MRM and compared with manual 3D contour segmentation (manual volume measurement, MVM, reference measurement technique) and volume estimates based on maximum diameter measurement (MDM). Compared with MVM as reference method MDM, AVM and SAVM underestimated lesion volumes by 63.8%, 30.9% and 21.5%, respectively, with significantly different accuracy for benign (102.4%, 18.4% and 11.4%) and malignant (54.9%, 33.0% and 23.1%) lesions (p < 0.05). Inter- and intraobserver reproducibility was best for AVM (mean difference +/- 2SD, 1.0 +/- 9.7% and 1.8 +/- 12.1%) followed by SAVM (4.3 +/- 25.7% and 4.3 +/- 7.9%), MVM (2.3 +/- 38.2% and 8.6 +/- 31.8%) and MDM (33.9 +/- 128.4% and 9.3 +/- 55.9%). SAVM is more accurate for volume assessment of breast lesions than MDM and AVM. Volume measurement is less accurate for malignant than benign lesions.

Epizootiologic studies of avian vacuolar myelinopathy in waterbirds

USGS Publications Warehouse

Rocke, Tonie E.; Thomas, N.J.; Augspurger, T.; Miller, Kimberli J.

2002-01-01

Epizootic avian vacuolar myelinopathy (AVM) was first recognized as a neurologic disease in bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana) in Arkansas, USA in 1994 and 1996, respectively, but attempts to identify the etiology of the disease have been unsuccessful to date. Between 1998 and 2001, wing clipped sentinel birds (wild American coots and game farm mallards [Anas platyrhynchos]) were released at Lake Surf, North Carolina, a lake with recurrent outbreaks of AVM, in order to gain a better understanding of the epizootiology of the disease. As early as 5-7 days post-release, sentinel coots and mallards showed neurologic signs of disease and were confirmed with AVM upon histologic examination of their brains. Serial releases of sentinel mallards during the summer, fall, and winter of 2000-01 demonstrated that exposure to the causative agent at a threshold sufficient to manifest disease was seasonal and occurred over about a 2 mo period, during November and December. Our findings that disease onset can be very rapid (5-7 days) and that exposure to the causative agent of AVM is site-specific, seasonal (late fall to early winter), and occurs over a relatively short duration (several months) supports the hypothesis that the disease is caused by a chemical substance, most likely of natural origin.

Visualization of semantic relations in geosicences

NASA Astrophysics Data System (ADS)

Ritschel, Bernd; Pfeiffer, Sabine; Mende, Vivien

2010-05-01

The discovery of semantic relations related to the content and context of scientific geophysical and geodetic data and information is a fundamental concept for an integrated scientific approach for the research of multidisciplinary and complex questions of the permanent changing Earth system. Large high-quality and multi-domain geosciences datasets which are qualified by significant and standardized metadata describing the content and especially the context of the data are suitable for the search and discovery of semantic relations. Nowadays such data collections are ingested and provided by many national and international geoscientific data centers, such as e.g. the GFZ ISDC(1). Beside automatic and machine-based algorithm for the discovery of semantic relations, the graphical visualization of such relations are extremely capable for scientist in order to analyze complex datasets and to find sophisticated relations as well as for the public in order to understand the relations within geosciences and between geosciences and societal domains. There are different tools for the visualization of relations, especially in the object-oriented based analysis and development of systems and software. The tool eyePlorer(2) is an awarded program for the visualization of multi-domain semantic relations in the public world of Wikipedia. The data and information for the visualization of keyword based terms and concepts within one domain or topic as well as the relations to other topics are mainly based on wiki content and appropriate structures. eyePlorer's main topics structured and combined in super topics are Health, Species and Life Sciences, Persons and Organisations, Work and Society, Science & Technology as well as Time and Places. Considering the domains or topics of the conceptual model of the GFZ ISDC's data collection, such topics as geosciences-related project, platform, instrument, product type, publication and institution as well as space and time are disjunct and complement sets or subsets or intersections of eyePlorer's topics. The introduction of new topics and the enhancement of the conceptual data model of the eyePlorer as well as the transformation of GFZ ISDC's metadata into a wiki structure or into eyePlorer's internal data format are necessary for the use in eyePlorer for the visualization of geosciences and societal relations based on both, the Wikipedia information collection and the GFZ ISDC metadata. This paper deals with the analysis of eyePlorer's and GFZ ISDC's concepts for the creation of an integrated conceptual model. Furthermore, the transformation model for the conversion of ISDC's metadata into appropriate structures for the use of eyePlorer is described. Finally, the process of semantic visualization of geosciences and societal relations within eyePlorer and using eyePlorer's GUI are illustrated on a climate research related example which is capable to generate knowledge not only for geoscientists but also for the public. (1) GFZ ISDC: GFZ Information System and Data Center, http://isdc.gfz-potsdam.de (2) eyePlorer: http://en.eyeplorer.com/show/

Architecture of a spatial data service system for statistical analysis and visualization of regional climate changes

NASA Astrophysics Data System (ADS)

Titov, A. G.; Okladnikov, I. G.; Gordov, E. P.

2017-11-01

The use of large geospatial datasets in climate change studies requires the development of a set of Spatial Data Infrastructure (SDI) elements, including geoprocessing and cartographical visualization web services. This paper presents the architecture of a geospatial OGC web service system as an integral part of a virtual research environment (VRE) general architecture for statistical processing and visualization of meteorological and climatic data. The architecture is a set of interconnected standalone SDI nodes with corresponding data storage systems. Each node runs a specialized software, such as a geoportal, cartographical web services (WMS/WFS), a metadata catalog, and a MySQL database of technical metadata describing geospatial datasets available for the node. It also contains geospatial data processing services (WPS) based on a modular computing backend realizing statistical processing functionality and, thus, providing analysis of large datasets with the results of visualization and export into files of standard formats (XML, binary, etc.). Some cartographical web services have been developed in a system’s prototype to provide capabilities to work with raster and vector geospatial data based on OGC web services. The distributed architecture presented allows easy addition of new nodes, computing and data storage systems, and provides a solid computational infrastructure for regional climate change studies based on modern Web and GIS technologies.

Integrated workflows for spiking neuronal network simulations

PubMed Central

Antolík, Ján; Davison, Andrew P.

2013-01-01

The increasing availability of computational resources is enabling more detailed, realistic modeling in computational neuroscience, resulting in a shift toward more heterogeneous models of neuronal circuits, and employment of complex experimental protocols. This poses a challenge for existing tool chains, as the set of tools involved in a typical modeler's workflow is expanding concomitantly, with growing complexity in the metadata flowing between them. For many parts of the workflow, a range of tools is available; however, numerous areas lack dedicated tools, while integration of existing tools is limited. This forces modelers to either handle the workflow manually, leading to errors, or to write substantial amounts of code to automate parts of the workflow, in both cases reducing their productivity. To address these issues, we have developed Mozaik: a workflow system for spiking neuronal network simulations written in Python. Mozaik integrates model, experiment and stimulation specification, simulation execution, data storage, data analysis and visualization into a single automated workflow, ensuring that all relevant metadata are available to all workflow components. It is based on several existing tools, including PyNN, Neo, and Matplotlib. It offers a declarative way to specify models and recording configurations using hierarchically organized configuration files. Mozaik automatically records all data together with all relevant metadata about the experimental context, allowing automation of the analysis and visualization stages. Mozaik has a modular architecture, and the existing modules are designed to be extensible with minimal programming effort. Mozaik increases the productivity of running virtual experiments on highly structured neuronal networks by automating the entire experimental cycle, while increasing the reliability of modeling studies by relieving the user from manual handling of the flow of metadata between the individual workflow stages. PMID:24368902

Integrated workflows for spiking neuronal network simulations.

PubMed

Antolík, Ján; Davison, Andrew P

2013-01-01

The increasing availability of computational resources is enabling more detailed, realistic modeling in computational neuroscience, resulting in a shift toward more heterogeneous models of neuronal circuits, and employment of complex experimental protocols. This poses a challenge for existing tool chains, as the set of tools involved in a typical modeler's workflow is expanding concomitantly, with growing complexity in the metadata flowing between them. For many parts of the workflow, a range of tools is available; however, numerous areas lack dedicated tools, while integration of existing tools is limited. This forces modelers to either handle the workflow manually, leading to errors, or to write substantial amounts of code to automate parts of the workflow, in both cases reducing their productivity. To address these issues, we have developed Mozaik: a workflow system for spiking neuronal network simulations written in Python. Mozaik integrates model, experiment and stimulation specification, simulation execution, data storage, data analysis and visualization into a single automated workflow, ensuring that all relevant metadata are available to all workflow components. It is based on several existing tools, including PyNN, Neo, and Matplotlib. It offers a declarative way to specify models and recording configurations using hierarchically organized configuration files. Mozaik automatically records all data together with all relevant metadata about the experimental context, allowing automation of the analysis and visualization stages. Mozaik has a modular architecture, and the existing modules are designed to be extensible with minimal programming effort. Mozaik increases the productivity of running virtual experiments on highly structured neuronal networks by automating the entire experimental cycle, while increasing the reliability of modeling studies by relieving the user from manual handling of the flow of metadata between the individual workflow stages.

Federal Data Repository Research: Recent Developments in Mercury Search System Architecture

NASA Astrophysics Data System (ADS)

Devarakonda, R.

2015-12-01

New data intensive project initiatives needs new generation data system architecture. This presentation will discuss the recent developments in Mercury System [1] including adoption, challenges, and future efforts to handle such data intensive projects. Mercury is a combination of three main tools (i) Data/Metadata registration Tool (Online Metadata Editor): The new Online Metadata Editor (OME) is a web-based tool to help document the scientific data in a well-structured, popular scientific metadata formats. (ii) Search and Visualization Tool: Provides a single portal to information contained in disparate data management systems. It facilitates distributed metadata management, data discovery, and various visuzalization capabilities. (iii) Data Citation Tool: In collaboration with Department of Energy's Oak Ridge National Laboratory (ORNL) Mercury Consortium (funded by NASA, USGS and DOE), established a Digital Object Identifier (DOI) service. Mercury is a open source system, developed and managed at Oak Ridge National Laboratory and is currently being funded by three federal agencies, including NASA, USGS and DOE. It provides access to millions of bio-geo-chemical and ecological data; 30,000 scientists use it each month. Some recent data intensive projects that are using Mercury tool: USGS Science Data Catalog (http://data.usgs.gov/), Next-Generation Ecosystem Experiments (http://ngee-arctic.ornl.gov/), Carbon Dioxide Information Analysis Center (http://cdiac.ornl.gov/), Oak Ridge National Laboratory - Distributed Active Archive Center (http://daac.ornl.gov), SoilSCAPE (http://mercury.ornl.gov/soilscape). References: [1] Devarakonda, Ranjeet, et al. "Mercury: reusable metadata management, data discovery and access system." Earth Science Informatics 3.1-2 (2010): 87-94.

Modern radiosurgical and endovascular classification schemes for brain arteriovenous malformations.

PubMed

Tayebi Meybodi, Ali; Lawton, Michael T

2018-05-04

Stereotactic radiosurgery (SRS) and endovascular techniques are commonly used for treating brain arteriovenous malformations (bAVMs). They are usually used as ancillary techniques to microsurgery but may also be used as solitary treatment options. Careful patient selection requires a clear estimate of the treatment efficacy and complication rates for the individual patient. As such, classification schemes are an essential part of patient selection paradigm for each treatment modality. While the Spetzler-Martin grading system and its subsequent modifications are commonly used for microsurgical outcome prediction for bAVMs, the same system(s) may not be easily applicable to SRS and endovascular therapy. Several radiosurgical- and endovascular-based grading scales have been proposed for bAVMs. However, a comprehensive review of these systems including a discussion on their relative advantages and disadvantages is missing. This paper is dedicated to modern classification schemes designed for SRS and endovascular techniques.

Imaging of Hereditary Hemorrhagic Telangiectasia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carette, Marie-France, E-mail: marie-france.carette@tnn.aphp.fr; Nedelcu, Cosmina; Tassart, Marc

This pictorial review is based on our experience of the follow-up of 120 patients at our multidisciplinary center for hereditary hemorrhagic telangiectasia (HHT). Rendu-Osler-Weber disease or HHT is a multiorgan autosomal dominant disorder with high penetrance, characterized by epistaxis, mucocutaneous telangiectasis, and visceral arteriovenous malformations (AVMs). The research on gene mutations is fundamental and family screening by clinical examination, chest X-ray, research of pulmonary shunting, and abdominal color Doppler sonography is absolutely necessary. The angioarchitecture of pulmonary AVMs can be studied by unenhanced multidetector computed tomography; however, all other explorations of liver, digestive bowels, or brain require administration of contrastmore » media. Magnetic resonance angiography is helpful for central nervous system screening, in particular for the spinal cord, but also for pulmonary, hepatic, and pelvic AVMs. Knowledge of the multiorgan involvement of HHT, mechanism of complications, and radiologic findings is fundamental for the correct management of these patients.« less

Linear accelerator radiosurgery for arteriovenous malformations: Updated literature review.

PubMed

Yahya, S; Heyes, G; Nightingale, P; Lamin, S; Chavda, S; Geh, I; Spooner, D; Cruickshank, G; Sanghera, P

2017-04-01

Arteriovenous malformations (AVMs) are the leading causing of intra-cerebral haemorrhage. Stereotactic radiosurgery (SRS) is an established treatment for arteriovenous malformations (AVM) and commonly delivered using Gamma Knife within dedicated radiosurgery units. Linear accelerator (LINAC) SRS is increasingly available however debate remains over whether it offers an equivalent outcome. The aim of this project is to evaluate the outcomes using LINAC SRS for AVMs used within a UK neurosciences unit and review the literature to aid decision making across various SRS platforms. Results have shown comparability across platforms and strongly supports that an adapted LINAC based SRS facility within a dynamic regional neuro-oncology department delivers similar outcomes (in terms of obliteration and toxicity) to any other dedicated radio-surgical platform. Locally available facilities can facilitate discussion between options however throughput will inevitably be lower than centrally based dedicated national radiosurgery units. Copyright © 2016. Published by Elsevier Ltd.

ClipCard: Sharable, Searchable Visual Metadata Summaries on the Cloud to Render Big Data Actionable

NASA Astrophysics Data System (ADS)

Saripalli, P.; Davis, D.; Cunningham, R.

2013-12-01

Research firm IDC estimates that approximately 90 percent of the Enterprise Big Data go un-analyzed, as 'dark data' - an enormous corpus of undiscovered, untagged information residing on data warehouses, servers and Storage Area Networks (SAN). In the geosciences, these data range from unpublished model runs to vast survey data assets to raw sensor data. Many of these are now being collected instantaneously, at a greater volume and in new data formats. Not all of these data can be analyzed, nor processed in real time, and their features may not be well described at the time of collection. These dark data are a serious data management problem for science organizations of all types, especially ones with mandated or required data reporting and compliance requirements. Additionally, data curators and scientists are encouraged to quantify the impact of their data holdings as a way to measure research success. Deriving actionable insights is the foremost goal of Big Data Analytics (BDA), which is especially true with geoscience, given its direct impact on most of the pressing global issues. Clearly, there is a pressing need for innovative approaches to making dark data discoverable, measurable, and actionable. We report on ClipCard, a Cloud-based SaaS analytic platform for instant summarization, quick search, visualization and easy sharing of metadata summaries form the Dark Data at hierarchical levels of detail, thus rendering it 'white', i.e., actionable. We present a use case of the ClipCard platform, a cloud-based application which helps generate (abstracted) visual metadata summaries and meta-analytics for environmental data at hierarchical scales within and across big data containers. These summaries and analyses provide important new tools for managing big data and simplifying collaboration through easy to deploy sharing APIs. The ClipCard application solves a growing data management bottleneck by helping enterprises and large organizations to summarize, search, discover, and share the potential in their unused data and information assets. Using Cloud as the base platform enables wider reach, quick dissemination and easy sharing of the metadata summaries, without actually storing or sharing the original data assets per se.

Pretreatment Predictors of Adverse Radiation Effects After Radiosurgery for Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayhurst, Caroline; Monsalves, Eric; Prooijen, Monique van

Purpose: To identify vascular and dosimetric predictors of symptomatic T2 signal change and adverse radiation effects after radiosurgery for arteriovenous malformation, in order to define and validate preexisting risk models. Methods and Materials: A total of 125 patients with arteriovenous malformations (AVM) were treated at our institution between 2005 and 2009. Eighty-five patients have at least 12 months of clinical and radiological follow-up. Any new-onset headaches, new or worsening seizures, or neurological deficit were considered adverse events. Follow-up magnetic resonance images were assessed for new onset T2 signal change and the volume calculated. Pretreatment characteristics and dosimetric variables were analyzedmore » to identify predictors of adverse radiation effects. Results: There were 19 children and 66 adults in the study cohort, with a mean age of 34 (range 6-74). Twenty-three (27%) patients suffered adverse radiation effects (ARE), 9 patients with permanent neurological deficit (10.6%). Of these, 5 developed fixed visual field deficits. Target volume and 12 Gy volume were the most significant predictors of adverse radiation effects on univariate analysis (p < 0.001). Location and cortical eloquence were not significantly associated with the development of adverse events (p = 0.12). No additional vascular parameters were identified as predictive of ARE. There was a significant target volume threshold of 4 cm{sup 3}, above which the rate of ARE increased dramatically. Multivariate analysis target volume and the absence of prior hemorrhage are the only significant predictors of ARE. The volume of T2 signal change correlates to ARE, but only target volume is predictive of a higher volume of T2 signal change. Conclusions: Target volume and the absence of prior hemorrhage is the most accurate predictor of adverse radiation effects and complications after radiosurgery for AVMs. A high percentage of permanent visual field defects in this series suggest the optic radiation is a critical radiosensitive structure.« less

GeoSearch: A lightweight broking middleware for geospatial resources discovery

NASA Astrophysics Data System (ADS)

Gui, Z.; Yang, C.; Liu, K.; Xia, J.

2012-12-01

With petabytes of geodata, thousands of geospatial web services available over the Internet, it is critical to support geoscience research and applications by finding the best-fit geospatial resources from the massive and heterogeneous resources. Past decades' developments witnessed the operation of many service components to facilitate geospatial resource management and discovery. However, efficient and accurate geospatial resource discovery is still a big challenge due to the following reasons: 1)The entry barriers (also called "learning curves") hinder the usability of discovery services to end users. Different portals and catalogues always adopt various access protocols, metadata formats and GUI styles to organize, present and publish metadata. It is hard for end users to learn all these technical details and differences. 2)The cost for federating heterogeneous services is high. To provide sufficient resources and facilitate data discovery, many registries adopt periodic harvesting mechanism to retrieve metadata from other federated catalogues. These time-consuming processes lead to network and storage burdens, data redundancy, and also the overhead of maintaining data consistency. 3)The heterogeneous semantics issues in data discovery. Since the keyword matching is still the primary search method in many operational discovery services, the search accuracy (precision and recall) is hard to guarantee. Semantic technologies (such as semantic reasoning and similarity evaluation) offer a solution to solve these issues. However, integrating semantic technologies with existing service is challenging due to the expandability limitations on the service frameworks and metadata templates. 4)The capabilities to help users make final selection are inadequate. Most of the existing search portals lack intuitive and diverse information visualization methods and functions (sort, filter) to present, explore and analyze search results. Furthermore, the presentation of the value-added additional information (such as, service quality and user feedback), which conveys important decision supporting information, is missing. To address these issues, we prototyped a distributed search engine, GeoSearch, based on brokering middleware framework to search, integrate and visualize heterogeneous geospatial resources. Specifically, 1) A lightweight discover broker is developed to conduct distributed search. The broker retrieves metadata records for geospatial resources and additional information from dispersed services (portals and catalogues) and other systems on the fly. 2) A quality monitoring and evaluation broker (i.e., QoS Checker) is developed and integrated to provide quality information for geospatial web services. 3) The semantic assisted search and relevance evaluation functions are implemented by loosely interoperating with ESIP Testbed component. 4) Sophisticated information and data visualization functionalities and tools are assembled to improve user experience and assist resource selection.

The VIMS Data Explorer: A tool for locating and visualizing hyperspectral data

NASA Astrophysics Data System (ADS)

Pasek, V. D.; Lytle, D. M.; Brown, R. H.

2016-12-01

Since successfully entering Saturn's orbit during Summer 2004 there have been over 300,000 hyperspectral data cubes returned from the visible and infrared mapping spectrometer (VIMS) instrument onboard the Cassini spacecraft. The VIMS Science Investigation is a multidisciplinary effort that uses these hyperspectral data to study a variety of scientific problems, including surface characterizations of the icy satellites and atmospheric analyses of Titan and Saturn. Such investigations may need to identify thousands of exemplary data cubes for analysis and can span many years in scope. Here we describe the VIMS data explorer (VDE) application, currently employed by the VIMS Investigation to search for and visualize data. The VDE application facilitates real-time inspection of the entire VIMS hyperspectral dataset, the construction of in situ maps, and markers to save and recall work. The application relies on two databases to provide comprehensive search capabilities. The first database contains metadata for every cube. These metadata searches are used to identify records based on parameters such as target, observation name, or date taken; they fall short in utility for some investigations. The cube metadata contains no target geometry information. Through the introduction of a post-calibration pixel database, the VDE tool enables users to greatly expand their searching capabilities. Users can select favorable cubes for further processing into 2-D and 3-D interactive maps, aiding in the data interpretation and selection process. The VDE application enables efficient search, visualization, and access to VIMS hyperspectral data. It is simple to use, requiring nothing more than a browser for access. Hyperspectral bands can be individually selected or combined to create real-time color images, a technique commonly employed by hyperspectral researchers to highlight compositional differences.

Single-Fraction Proton Beam Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hattangadi-Gluth, Jona A.; Chapman, Paul H.; Kim, Daniel

2014-06-01

Purpose/Objective(s): To evaluate the obliteration rate and potential adverse effects of single-fraction proton beam stereotactic radiosurgery (PSRS) in patients with cerebral arteriovenous malformations (AVMs). Methods and Materials: From 1991 to 2010, 248 consecutive patients with 254 cerebral AVMs received single-fraction PSRS at our institution. The median AVM nidus volume was 3.5 cc (range, 0.1-28.1 cc), 23% of AVMs were in critical/deep locations (basal ganglia, thalamus, or brainstem), and the most common prescription dose was 15 Gy(relative biological effectiveness [RBE]). Univariable and multivariable analyses were performed to assess factors associated with obliteration and hemorrhage. Results: At a median follow-up time of 35 months (range, 6-198 months),more » 64.6% of AVMs were obliterated. The median time to total obliteration was 31 months (range, 6-127 months), and the 5-year and 10-year cumulative incidence of total obliteration was 70% and 91%, respectively. On univariable analysis, smaller target volume (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.86-0.93, P<.0001), smaller treatment volume (HR 0.93, 95% CI 0.90-0.96, P<.0001), higher prescription dose (HR 1.16, 95% CI 1.07-1.26, P=.001), and higher maximum dose (HR 1.14, 95% CI 1.05-1.23, P=.002) were associated with total obliteration. Deep/critical location was also associated with decreased likelihood of obliteration (HR 0.68, 95% CI 0.47-0.98, P=.04). On multivariable analysis, critical location (adjusted HR [AHR] 0.42, 95% CI 0.27-0.65, P<.001) and smaller target volume (AHR 0.81, 95% CI 0.68-0.97, P=.02) remained associated with total obliteration. Posttreatment hemorrhage occurred in 13 cases (5-year cumulative incidence of 7%), all among patients with less than total obliteration, and 3 of these events were fatal. The most common complication was seizure, controlled with medications, both acutely (8%) and in the long term (9.1%). Conclusions: The current series is the largest modern series of PSRS for cerebral AVMs. PSRS can achieve a high obliteration rate with minimal morbidity. Post-treatment hemorrhage remains a potentially fatal risk among patients who have not yet responded to treatment.« less

MultiFacet: A Faceted Interface for Browsing Large Multimedia Collections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, Michael J.; Hampton, Shawn D.; Endert, Alexander

2013-10-31

Faceted browsing is a common technique for exploring collections where the data can be grouped into a number of pre-defined categories, most often generated from textual metadata. Historically, faceted browsing has been applied to a single data type such as text or image data. However, typical collections contain multiple data types, such as information from web pages that contain text, images, and video. Additionally, when browsing a collection of images and video, facets are often created based on the metadata which may be incomplete, inaccurate, or missing altogether instead of the actual visual content contained within those images and video.more » In this work we address these limitations by presenting MultiFacet, a faceted browsing interface that supports multiple data types. MultiFacet constructs facets for images and video in a collection from the visual content using computer vision techniques. These visual facets can then be browsed in conjunction with text facets within a single interface to reveal relationships and phenomena within multimedia collections. Additionally, we present a use case based on real-world data, demonstrating the utility of this approach towards browsing a large multimedia data collection.« less

Naval Weapons Bulletin. October-December, Number 4-62.

DTIC Science & Technology

1962-12-01

conducted on the prototype installa- by continuously to execute pre-recorded tion in USS NORTON SOUND ( AVM -1). commands. One of these commands will (See...1T[LMET[IIING TACAN",- TOWER STACK /AN/SPG-59 MISSILE / Figure 1. --Computed radiation hazard zone, USS NORTON SOUND ( AVM -lI) CONFIDENTIAL C7...equipment also located in the checkout area are the Signal Comparator CM- 12Z/ DSM and the Telemetric Data Receiving, Recording, and Scoring Set AN/SKQ

Novel Image-Guided Management of a Uterine Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Przybojewski, Stefan J., E-mail: drstefanp@hotmail.com; Sadler, David J.

The investigators present a novel image-guided embolization, not previously described, of a uterine arteriovenous malformation (AVM) resistant to endovascular management. The uterus was exposed surgically, and Histoacryl (Braun, Fulda, Germany) was injected directly into the nidus using ultrasound guidance and fluoroscopy. The patient had a successful full-term pregnancy after this procedure. This technique may be a useful alternative management strategy in patients with uterine AVM who fail traditional endovascular embolization and who still desire fertility.

Conventional digital subtractional vs non-invasive MR angiography in the assessment of brain arteriovenous malformation.

PubMed

Cuong, Nguyen Ngoc; Luu, Vu Dang; Tuan, Tran Anh; Linh, Le Tuan; Hung, Kieu Dinh; Ngoc, Vo Truong Nhu; Sharma, Kulbhushan; Pham, Van Huy; Chu, Dinh-Toi

2018-06-01

Digital subtractional angiography (DSA) is the standard method for diagnosis, assessment and management of arteriovenous malformation in the brain. Conventional DSA (cDSA) is an invasive imaging modality that is often indicated before interventional treatments (embolization, open surgery, gamma knife). Here, we aimed to compare this technique with a non-invasive MR angiography (MRI DSA) for brain arteriovenous malformation (bAVM). Fourteen patients with ruptured brain AVM underwent embolization treatment pre-operation. Imaging was performed for all patients using MRI (1.5 T). After injecting contrast Gadolinium, dynamic MRI was performed with 40 phases, each phase of a duration of 1.2 s and having 70 images. The MRI results were independently assessed by experienced radiologist blinded to the cDSA. The AVM nidus was depicted in all patients using cDSA and MRI DSA; there was an excellent correlation between these techniques in terms of the maximum diameter and Spetzler Martin grading. Of the fourteen patients, the drainage vein was depicted in 13 by both cDSA and MRI DSA showing excellent correlation between the techniques used. MRI DSA is a non-invasive imaging modality that can give the images in dynamic view. It can be considered as an adjunctive method with cDSA to plan the strategy treatment for bAVM. Copyright © 2018 Elsevier B.V. All rights reserved.

Progesterone receptors identified in vascular malformations of the head and neck.

PubMed

Duyka, Landon J; Fan, Chun Y; Coviello-Malle, Jean M; Buckmiller, Lisa; Suen, James Y

2009-10-01

To identify hormone receptors within vascular malformations (arteriovenous malformations [AVMs], venous malformations [VMs], and lymphatic malformations [LMs]) of the head and neck. Immunohistochemical staining for estrogen receptor (ER) and progesterone receptor (PR) was performed on archival vascular malformation tissue collected from both pediatric and adult patients. Tertiary referral center from 2006 to 2008. Twelve AVM, 10 VM, and eight LM specimens were stained for both ER and PR. Ten breast carcinoma specimens were used as controls, with the carcinoma cells serving as positive controls, and the endothelium and smooth muscle cells of the blood vessels serving as negative controls. Five normal supraglottic mucosal samples served as head and neck controls. The Fisher exact test was used for statistical analysis. Ten of the 12 (83%) AVM specimens stained diffusely positive for PR within the nuclei of the endothelium and smooth muscle of the malformed vessels (P < 0.0001). Five of the 10 (50%) VM specimens stained positive for PR (2 [20%] focal, 3 [30%] diffuse) within the nuclei of the endothelium and smooth muscle of the malformed vessels (P = 0.0325). Four of the eight (50%) LM specimens stained focally positive for PR within the nuclei of the endothelium of the malformed vessels (P = 0.0229). None of the vascular malformation specimens stained positive for ER. Our data suggest that PR, but not ER, is expressed in AVMs, VMs, and LMs of the head and neck.

Novel techniques of real-time blood flow and functional mapping: technical note.

PubMed

Kamada, Kyousuke; Ogawa, Hiroshi; Saito, Masato; Tamura, Yukie; Anei, Ryogo; Kapeller, Christoph; Hayashi, Hideaki; Prueckl, Robert; Guger, Christoph

2014-01-01

There are two main approaches to intraoperative monitoring in neurosurgery. One approach is related to fluorescent phenomena and the other is related to oscillatory neuronal activity. We developed novel techniques to visualize blood flow (BF) conditions in real time, based on indocyanine green videography (ICG-VG) and the electrophysiological phenomenon of high gamma activity (HGA). We investigated the use of ICG-VG in four patients with moyamoya disease and two with arteriovenous malformation (AVM), and we investigated the use of real-time HGA mapping in four patients with brain tumors who underwent lesion resection with awake craniotomy. Real-time data processing of ICG-VG was based on perfusion imaging, which generated parameters including arrival time (AT), mean transit time (MTT), and BF of brain surface vessels. During awake craniotomy, we analyzed the frequency components of brain oscillation and performed real-time HGA mapping to identify functional areas. Processed results were projected on a wireless monitor linked to the operating microscope. After revascularization for moyamoya disease, AT and BF were significantly shortened and increased, respectively, suggesting hyperperfusion. Real-time fusion images on the wireless monitor provided anatomical, BF, and functional information simultaneously, and allowed the resection of AVMs under the microscope. Real-time HGA mapping during awake craniotomy rapidly indicated the eloquent areas of motor and language function and significantly shortened the operation time. These novel techniques, which we introduced might improve the reliability of intraoperative monitoring and enable the development of rational and objective surgical strategies.

Novel Techniques of Real-time Blood Flow and Functional Mapping: Technical Note

PubMed Central

KAMADA, Kyousuke; OGAWA, Hiroshi; SAITO, Masato; TAMURA, Yukie; ANEI, Ryogo; KAPELLER, Christoph; HAYASHI, Hideaki; PRUECKL, Robert; GUGER, Christoph

2014-01-01

There are two main approaches to intraoperative monitoring in neurosurgery. One approach is related to fluorescent phenomena and the other is related to oscillatory neuronal activity. We developed novel techniques to visualize blood flow (BF) conditions in real time, based on indocyanine green videography (ICG-VG) and the electrophysiological phenomenon of high gamma activity (HGA). We investigated the use of ICG-VG in four patients with moyamoya disease and two with arteriovenous malformation (AVM), and we investigated the use of real-time HGA mapping in four patients with brain tumors who underwent lesion resection with awake craniotomy. Real-time data processing of ICG-VG was based on perfusion imaging, which generated parameters including arrival time (AT), mean transit time (MTT), and BF of brain surface vessels. During awake craniotomy, we analyzed the frequency components of brain oscillation and performed real-time HGA mapping to identify functional areas. Processed results were projected on a wireless monitor linked to the operating microscope. After revascularization for moyamoya disease, AT and BF were significantly shortened and increased, respectively, suggesting hyperperfusion. Real-time fusion images on the wireless monitor provided anatomical, BF, and functional information simultaneously, and allowed the resection of AVMs under the microscope. Real-time HGA mapping during awake craniotomy rapidly indicated the eloquent areas of motor and language function and significantly shortened the operation time. These novel techniques, which we introduced might improve the reliability of intraoperative monitoring and enable the development of rational and objective surgical strategies. PMID:25263624

mvMapper: statistical and geographical data exploration and visualization of multivariate analysis of population structure

USDA-ARS?s Scientific Manuscript database

Characterizing population genetic structure across geographic space is a fundamental challenge in population genetics. Multivariate statistical analyses are powerful tools for summarizing genetic variability, but geographic information and accompanying metadata is not always easily integrated into t...

Consensus Document of the International Union of Angiology (IUA)-2013. Current concept on the management of arterio-venous management.

PubMed

Lee, B B; Baumgartner, I; Berlien, H P; Bianchini, G; Burrows, P; Do, Y S; Ivancev, K; Kool, L S; Laredo, J; Loose, D A; Lopez-Gutierrez, J C; Mattassi, R; Parsi, K; Rimon, U; Rosenblatt, M; Shortell, C; Simkin, R; Stillo, F; Villavicencio, L; Yakes, W

2013-02-01

Arterio-venous malformations (AVMs) are congenital vascular malformations (CVMs) that result from birth defects involving the vessels of both arterial and venous origins, resulting in direct communications between the different size vessels or a meshwork of primitive reticular networks of dysplastic minute vessels which have failed to mature to become 'capillary' vessels termed "nidus". These lesions are defined by shunting of high velocity, low resistance flow from the arterial vasculature into the venous system in a variety of fistulous conditions. A systematic classification system developed by various groups of experts (Hamburg classification, ISSVA classification, Schobinger classification, angiographic classification of AVMs,) has resulted in a better understanding of the biology and natural history of these lesions and improved management of CVMs and AVMs. The Hamburg classification, based on the embryological differentiation between extratruncular and truncular type of lesions, allows the determination of the potential of progression and recurrence of these lesions. The majority of all AVMs are extra-truncular lesions with persistent proliferative potential, whereas truncular AVM lesions are exceedingly rare. Regardless of the type, AV shunting may ultimately result in significant anatomical, pathophysiological and hemodynamic consequences. Therefore, despite their relative rarity (10-20% of all CVMs), AVMs remain the most challenging and potentially limb or life-threatening form of vascular anomalies. The initial diagnosis and assessment may be facilitated by non- to minimally invasive investigations such as duplex ultrasound, magnetic resonance imaging (MRI), MR angiography (MRA), computerized tomography (CT) and CT angiography (CTA). Arteriography remains the diagnostic gold standard, and is required for planning subsequent treatment. A multidisciplinary team approach should be utilized to integrate surgical and non-surgical interventions for optimum care. Currently available treatments are associated with significant risk of complications and morbidity. However, an early aggressive approach to elimiate the nidus (if present) may be undertaken if the benefits exceed the risks. Trans-arterial coil embolization or ligation of feeding arteries where the nidus is left intact, are incorrect approaches and may result in proliferation of the lesion. Furthermore, such procedures would prevent future endovascular access to the lesions via the arterial route. Surgically inaccessible, infiltrating, extra-truncular AVMs can be treated with endovascular therapy as an independent modality. Among various embolo-sclerotherapy agents, ethanol sclerotherapy produces the best long term outcomes with minimum recurrence. However, this procedure requires extensive training and sufficient experience to minimize complications and associated morbidity. For the surgically accessible lesions, surgical resection may be the treatment of choice with a chance of optimal control. Preoperative sclerotherapy or embolization may supplement the subsequent surgical excision by reducing the morbidity (e.g. operative bleeding) and defining the lesion borders. Such a combined approach may provide an excellent potential for a curative result. Conclusion. AVMs are high flow congenital vascular malformations that may occur in any part of the body. The clinical presentation depends on the extent and size of the lesion and can range from an asymptomatic birthmark to congestive heart failure. Detailed investigations including duplex ultrasound, MRI/MRA and CT/CTA are required to develop an appropriate treatment plan. Appropriate management is best achieved via a multi-disciplinary approach and interventions should be undertaken by appropriately trained physicians.

Stereotactic radiosurgery for arteriovenous malformations after Onyx embolization: a case-control study.

PubMed

Lee, Cheng-Chia; Chen, Ching-Jen; Ball, Benjamin; Schlesinger, David; Xu, Zhiyuan; Yen, Chun-Po; Sheehan, Jason

2015-07-01

Onyx, an ethylene-vinyl alcohol copolymer mixed in a dimethyl sulfoxide solvent, is currently one of the most widely used liquid materials for embolization of intracranial arteriovenous malformations (AVMs). The goal of this study was to define the risks and benefits of stereotactic radiosurgery (SRS) for patients who have previously undergone partial AVM embolization with Onyx. Among a consecutive series of 199 patients who underwent SRS between January 2007 and December 2012 at the University of Virginia, 25 patients had Onyx embolization prior to SRS (the embolization group). To analyze the obliteration rates and complications, 50 patients who underwent SRS without prior embolization (the no-embolization group) were matched by propensity score method. The matched variables included age, sex, nidus volume before SRS, margin dose, Spetzler-Martin grade, Virginia Radiosurgery AVM Scale score, and median imaging follow-up period. After Onyx embolization, 18 AVMs were reduced in size. Total obliteration was achieved in 6 cases (24%) at a median of 27.5 months after SRS. In the no-embolization group, total obliteration was achieved in 20 patients (40%) at a median of 22.4 months after SRS. Kaplan-Meier analysis demonstrated obliteration rates of 17.7% and 34.1% in the embolization group at 2 and 4 years, respectively. In the no-embolization group, the corresponding obliteration rates were 27.0% and 55.9%. The between-groups difference in obliteration rates after SRS did not achieve statistical significance. The difference in complications, including adverse radiation effects, hemorrhage episodes, seizure control, and patient mortality also did not reach statistical significance. Onyx embolization can effectively reduce the size of many AVMs. This case-control study did not show any statistically significant difference in the rates of embolization or complications after SRS in patients who had previously undergone Onyx embolization and those who had not.

At-vessel mortality of skates (Rajidae) taken in coastal fisheries and evidence of longer-term survival.

PubMed

Ellis, J R; Burt, G J; Grilli, G; McCully Phillips, S R; Catchpole, T L; Maxwell, D L

2018-06-01

Data on the vigour and at-vessel mortality (AVM) of 6798 skates (comprising Raja clavata n = 6295; R. brachyura n = 208; R. undulata n = 185, R. montagui n = 98 and R. microocellata n = 12) captured by commercial fishing vessels in the inshore waters of the southern North Sea and English Channel were recorded. AVM in longline fisheries averaged 0·44% across five vessels (0-1·47%), although skates were usually unhooked manually and did not usually pass through a bait-stripper. AVM in otter trawls averaged 0·76% (0-2·35%), from four vessels fishing with tow durations of <1·5 h (southern North Sea) or 1-4 h (English Channel). No AVM was noted for skates taken as a by-catch in drift trammel nets (soak times <4 h). Anchored tangle nets resulted in an overall AVM of 2·0-2·7%, but increased from 1·47% (13-28 h soak time) to 6·16% (42-53 h soak time). There were significant differences in the vigour of skates between gears, with R. clavata caught by longline and tangle nets in better condition than those captured by otter trawl or drift trammel net. Similarly, R. undulata caught by tangle net were in better condition than those caught by otter trawl. The vigour of R. undulata was also found to be higher than other skate species for both trawl and tangle net. In total, 5283 skates were tagged with Petersen discs and released, with recapture rates for the various combinations of vessel and gear ranging up to 24·8% for R. clavata. Whilst confirming a degree of post-release survival, quantitative estimates of post-release mortality for skates remain unknown. © 2018 Crown Copyright. Journal of Fish Biology © 2018 The Fisheries Society of the British Isles.

The microbiological quality of pasteurized milk sold by automatic vending machines.

PubMed

Angelidis, A S; Tsiota, S; Pexara, A; Govaris, A

2016-06-01

The microbiological quality of pasteurized milk samples (n = 39) collected during 13 weekly intervals from three automatic vending machines (AVM) in Greece was investigated. Microbiological counts (total aerobic (TAC), total psychrotrophic (TPC), Enterobacteriaceae (EC), and psychrotrophic aerobic bacterial spore counts (PABSC)) were obtained at the time of sampling and at the end of shelf-life (3 days) after storage of the samples at 4 or 8°C. TAC were found to be below the 10(7 ) CFU ml(-1) limit of pasteurized milk spoilage both during sampling as well as when milk samples were stored at either storage temperature for 3 days. Enterobacteriaceae populations were below 1 CFU ml(-1) in 69·2% of the samples tested at the time of sampling, whereas the remaining samples contained low numbers, typically less than 10 CFU ml(-1) . All samples tested negative for the presence of Listeria monocytogenes. Analogous microbiological data were also obtained by sampling and testing prepackaged, retail samples of pasteurized milk from two dairy companies in Greece (n = 26). From a microbiological standpoint, the data indicate that the AVM milk samples meet the quality standards of pasteurized milk. However, the prepackaged, retail milk samples yielded better results in terms of TAC, TPC and EC, compared to the AVM samples at the end of shelf-life. Recently, Greek dairy farmers organized in cooperatives launched the sale of pasteurized milk via AVM and this study reports on the microbiological quality of this product. The data show that AVM milk is sold at proper refrigeration temperatures and meets the quality standards of pasteurized milk throughout the manufacturer's specified shelf-life. However, based on the microbiological indicators tested, the keeping quality of the tested prepackaged, retail samples of pasteurized milk at the end of shelf-life upon storage under suboptimal refrigeration temperature (8°C) was better. © 2016 The Society for Applied Microbiology.

Data System Architectures: Recent Experiences from Data Intensive Projects

NASA Astrophysics Data System (ADS)

Palanisamy, G.; Frame, M. T.; Boden, T.; Devarakonda, R.; Zolly, L.; Hutchison, V.; Latysh, N.; Krassovski, M.; Killeffer, T.; Hook, L.

2014-12-01

U.S. Federal agencies are frequently trying to address new data intensive projects that require next generation of data system architectures. This presentation will focus on two new such architectures: USGS's Science Data Catalog (SDC) and DOE's Next Generation Ecological Experiments - Arctic Data System. The U.S. Geological Survey (USGS) developed a Science Data Catalog (data.usgs.gov) to include records describing datasets, data collections, and observational or remotely-sensed data. The system was built using service oriented architecture and allows USGS scientists and data providers to create and register their data using either a standards-based metadata creation form or simply to register their already-created metadata records with the USGS SDC Dashboard. This dashboard then compiles the harvested metadata records and sends them to the post processing and indexing service using the JSON format. The post processing service, with the help of various ontologies and other geo-spatial validation services, auto-enhances these harvested metadata records and creates a Lucene index using the Solr enterprise search platform. Ultimately, metadata is made available via the SDC search interface. DOE's Next Generation Ecological Experiments (NGEE) Arctic project deployed a data system that allows scientists to prepare, publish, archive, and distribute data from field collections, lab experiments, sensors, and simulated modal outputs. This architecture includes a metadata registration form, data uploading and sharing tool, a Digital Object Identifier (DOI) tool, a Drupal based content management tool (http://ngee-arctic.ornl.gov), and a data search and access tool based on ORNL's Mercury software (http://mercury.ornl.gov). The team also developed Web-metric tools and a data ingest service to visualize geo-spatial and temporal observations.

The GEOSS Clearinghouse based on the GeoNetwork opensource

NASA Astrophysics Data System (ADS)

Liu, K.; Yang, C.; Wu, H.; Huang, Q.

2010-12-01

The Global Earth Observation System of Systems (GEOSS) is established to support the study of the Earth system in a global community. It provides services for social management, quick response, academic research, and education. The purpose of GEOSS is to achieve comprehensive, coordinated and sustained observations of the Earth system, improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behavior of the Earth system. In 2009, GEO called for a competition for an official GEOSS clearinghouse to be selected as a source to consolidating catalogs for Earth observations. The Joint Center for Intelligent Spatial Computing at George Mason University worked with USGS to submit a solution based on the open-source platform - GeoNetwork. In the spring of 2010, the solution is selected as the product for GEOSS clearinghouse. The GEOSS Clearinghouse is a common search facility for the Intergovernmental Group on Ea rth Observation (GEO). By providing a list of harvesting functions in Business Logic, GEOSS clearinghouse can collect metadata from distributed catalogs including other GeoNetwork native nodes, webDAV/sitemap/WAF, catalog services for the web (CSW)2.0, GEOSS Component and Service Registry (http://geossregistries.info/), OGC Web Services (WCS, WFS, WMS and WPS), OAI Protocol for Metadata Harvesting 2.0, ArcSDE Server and Local File System. Metadata in GEOSS clearinghouse are managed in a database (MySQL, Postgresql, Oracle, or MckoiDB) and an index of the metadata is maintained through Lucene engine. Thus, EO data, services, and related resources can be discovered and accessed. It supports a variety of geospatial standards including CSW and SRU for search, FGDC and ISO metadata, and WMS related OGC standards for data access and visualization, as linked from the metadata.

New Tools to Document and Manage Data/Metadata: Example NGEE Arctic and UrbIS

NASA Astrophysics Data System (ADS)

Crow, M. C.; Devarakonda, R.; Hook, L.; Killeffer, T.; Krassovski, M.; Boden, T.; King, A. W.; Wullschleger, S. D.

2016-12-01

Tools used for documenting, archiving, cataloging, and searching data are critical pieces of informatics. This discussion describes tools being used in two different projects at Oak Ridge National Laboratory (ORNL), but at different stages of the data lifecycle. The Metadata Entry and Data Search Tool is being used for the documentation, archival, and data discovery stages for the Next Generation Ecosystem Experiment - Arctic (NGEE Arctic) project while the Urban Information Systems (UrbIS) Data Catalog is being used to support indexing, cataloging, and searching. The NGEE Arctic Online Metadata Entry Tool [1] provides a method by which researchers can upload their data and provide original metadata with each upload. The tool is built upon a Java SPRING framework to parse user input into, and from, XML output. Many aspects of the tool require use of a relational database including encrypted user-login, auto-fill functionality for predefined sites and plots, and file reference storage and sorting. The UrbIS Data Catalog is a data discovery tool supported by the Mercury cataloging framework [2] which aims to compile urban environmental data from around the world into one location, and be searchable via a user-friendly interface. Each data record conveniently displays its title, source, and date range, and features: (1) a button for a quick view of the metadata, (2) a direct link to the data and, for some data sets, (3) a button for visualizing the data. The search box incorporates autocomplete capabilities for search terms and sorted keyword filters are available on the side of the page, including a map for searching by area. References: [1] Devarakonda, Ranjeet, et al. "Use of a metadata documentation and search tool for large data volumes: The NGEE arctic example." Big Data (Big Data), 2015 IEEE International Conference on. IEEE, 2015. [2] Devarakonda, R., Palanisamy, G., Wilson, B. E., & Green, J. M. (2010). Mercury: reusable metadata management, data discovery and access system. Earth Science Informatics, 3(1-2), 87-94.

Mechanical removal of a refluxed Onyx piece from the middle cerebral artery using the Solitaire Stent: Technical report.

PubMed

Gungor, Dilara; Oğuz, Şükrü; Dinc, Hasan

2017-06-01

Onyx reflux into the parent artery is a rare and sometimes significant complication in the treatment of cerebral arteriovenous malformations (AVMs). We report a patient who presented with Onyx reflux into the M1 segment of the middle cerebral artery (MCA) during embolization of a right temporal AVM. The refluxed Onyx cast was successfully removed by a mechanical thrombectomy device using a self-expandable and fully retrievable Solitaire AB stent.

Mechanical removal of a refluxed Onyx piece from the middle cerebral artery using the Solitaire Stent: Technical report

PubMed Central

Oğuz, Şükrü; Dinc, Hasan

2017-01-01

Onyx reflux into the parent artery is a rare and sometimes significant complication in the treatment of cerebral arteriovenous malformations (AVMs). We report a patient who presented with Onyx reflux into the M1 segment of the middle cerebral artery (MCA) during embolization of a right temporal AVM. The refluxed Onyx cast was successfully removed by a mechanical thrombectomy device using a self-expandable and fully retrievable Solitaire AB stent. PMID:28604186

Arterio-venous malformations in childhood: clinical presentation, results after operative treatment and long-term follow-up.

PubMed

Kahl, W; Kessel, G; Schwarz, M; Voth, D

1989-01-01

In a series of 182 arterio-venous malformations (AVM) recently published we found 33 children aged 1 to 16 years. In 28 cases, the admitting condition was hemorrhage. For 31 AVMs total excision was possible. We observed one postoperative death accounting for a mortality of 3%. All children but two were followed-up by personal examination. Two were not able to work due to severe neurological deficits and seven had not been able to get into their intended occupation.

A Rules-Based Service for Suggesting Visualizations to Analyze Earth Science Phenomena.

NASA Astrophysics Data System (ADS)

Prabhu, A.; Zednik, S.; Fox, P. A.; Ramachandran, R.; Maskey, M.; Shie, C. L.; Shen, S.

2016-12-01

Current Earth Science Information Systems lack support for new or interdisciplinary researchers, who may be unfamiliar with the domain vocabulary or the breadth of relevant data available. We need to evolve the current information systems, to reduce the time required for data preparation, processing and analysis. This can be done by effectively salvaging the "dark" resources in Earth Science. We assert that Earth science metadata assets are dark resources, information resources that organizations collect, process, and store for regular business or operational activities but fail to utilize for other purposes. In order to effectively use these dark resources, especially for data processing and visualization, we need a combination of domain, data product and processing knowledge, i.e. a knowledge base from which specific data operations can be performed. In this presentation, we describe a semantic, rules based approach to provide i.e. a service to visualize Earth Science phenomena, based on the data variables extracted using the "dark" metadata resources. We use Jena rules to make assertions about compatibility between a phenomena and various visualizations based on multiple factors. We created separate orthogonal rulesets to map each of these factors to the various phenomena. Some of the factors we have considered include measurements, spatial resolution and time intervals. This approach enables easy additions and deletions based on newly obtained domain knowledge or phenomena related information and thus improving the accuracy of the rules service overall.

Report: New analytical and statistical approaches for interpreting the relationships among environmental stressors and biomarkers

EPA Science Inventory

The broad topic of biomarker research has an often-overlooked component: the documentation and interpretation of the surrounding chemical environment and other meta-data, especially from visualization, analytical, and statistical perspectives (Pleil et al. 2014; Sobus et al. 2011...

Microsoft Repository Version 2 and the Open Information Model.

ERIC Educational Resources Information Center

Bernstein, Philip A.; Bergstraesser, Thomas; Carlson, Jason; Pal, Shankar; Sanders, Paul; Shutt, David

1999-01-01

Describes the programming interface and implementation of the repository engine and the Open Information Model for Microsoft Repository, an object-oriented meta-data management facility that ships in Microsoft Visual Studio and Microsoft SQL Server. Discusses Microsoft's component object model, object manipulation, queries, and information…

Expanding Access to NCAR's Digital Assets: Towards a Unified Scientific Data Management System

NASA Astrophysics Data System (ADS)

Stott, D.

2016-12-01

In 2014 the National Center for Atmospheric Research (NCAR) Directorate created the Data Stewardship Engineering Team (DSET) to plan and implement the strategic vision of an integrated front door for data discovery and access across the organization, including all laboratories, the library, and UCAR Community Programs. The DSET is focused on improving the quality of users' experiences in finding and using NCAR's digital assets. This effort also supports new policies included in federal mandates, NSF requirements, and journal publication rules. An initial survey with 97 respondents identified 68 persons responsible for more than 3 petabytes of data. An inventory, using the Data Asset Framework produced by the UK Digital Curation Centre as a starting point, identified asset types that included files and metadata, publications, images, and software (visualization, analysis, model codes). User story sessions with representatives from each lab identified and ranked desired features for a unified Scientific Data Management System (SDMS). A process beginning with an organization-wide assessment of metadata by the HDF Group and followed by meetings with labs to identify key documentation concepts, culminated in the development of an NCAR metadata dialect that leverages the DataCite and ISO 19115 standards. The tasks ahead are to build out an SDMS and populate it with rich standardized metadata. Software packages have been prototyped and currently are being tested and reviewed by DSET members. Key challenges for the DSET include technical and non-technical issues. First, the status quo with regard to how assets are managed varies widely across the organization. There are differences in file format standards, technologies, and discipline-specific vocabularies. Metadata diversity is another real challenge. The types of metadata, the standards used, and the capacity to create new metadata varies across the organization. Significant effort is required to develop tools to create new standard metadata across the organization, adapt and integrate current digital assets, and establish consistent data management practices going forward. To be successful, best practices must be infused into daily activities. This poster will highlight the processes, lessons learned, and current status of the DSET effort at NCAR.

Dosimetric effects of Onyx embolization on Gamma Knife arteriovenous malformation dose distributions.

PubMed

Schlesinger, David J; Nordström, Håkan; Lundin, Anders; Xu, Zhiyuan; Sheehan, Jason P

2016-12-01

OBJECTIVE Patients with arteriovenous malformations (AVMs) treated with Gamma Knife radiosurgery (GKRS) subsequent to embolization suffer from elevated local failure rates and differences in adverse radiation effects. Onyx is a common embolic material for AVMs. Onyx is formulated with tantalum, a high atomic number (Z = 73) element that has been investigated as a source of dosimetric uncertainty contributing to the less favorable clinical results. However, prior studies have not modeled the complicated anatomical and beam geometries characteristic of GKRS. This study investigated the magnitude of dose perturbation that can occur due to Onyx embolization using clinically realistic anatomical and Gamma Knife beam models. METHODS Leksell GammaPlan (LGP) was used to segment the AVM nidus and areas of Onyx from postcontrast stereotactic MRI for 7 patients treated with GKRS postembolization. The resulting contours, skull surface, and clinically selected dose distributions were exported from LGP in DICOM-RT (Digital Imaging and Communications in Medicine-radiotherapy) format. Isocenter locations and dwell times were recorded from the LGP database. Contours were converted into 3D mesh representations using commercial and in-house mesh-editing software. The resulting data were imported into a Monte Carlo (MC) dose calculation engine (Pegasos, Elekta Instruments AB) with a beam geometry for the Gamma Knife Perfexion. The MC-predicted dose distributions were calculated with Onyx assigned manufacturer-reported physical constants (MC-Onyx), and then compared with corresponding distributions in which Onyx was reassigned constants for water (MC-water). Differences in dose metrics were determined, including minimum, maximum, and mean dose to the AVM nidus; selectivity index; and target coverage. Combined differences in dose magnitude and distance to agreement were calculated as 3D Gamma analysis passing rates using tolerance criteria of 0.5%/0.5 mm, 1.0%/1.0 mm, and 3.0%/3.0 mm. RESULTS Overall, the mean percentage differences in dose metrics for MC-Onyx relative to MC-water were as follows; all data are reported as mean (SD): minimum dose to AVM = -0.7% (1.4%), mean dose to AVM = 0.1% (0.2%), maximum dose to AVM = 2.9% (5.0%), selectivity = 0.1% (0.2%), and coverage = -0.0% (0.2%). The mean percentage of voxels passing at each Gamma tolerance were as follows: 99.7% (0.1%) for 3.0%/3.0 mm, 98.2% (0.7%) for 1.0%/1.0 mm, and 52.1% (4.4%) for 0.5%/0.5 mm. CONCLUSIONS Onyx embolization appears to have a detectable effect on the delivered dose distribution. However, the small changes in dose metrics and high Gamma passing rates at 1.0%/1.0 mm tolerance suggest that these changes are unlikely to be clinically significant. Additional sources of delivery and biological uncertainty should be investigated to determine the root cause of the observed less favorable postembolization GKRS outcomes.

Simplified RP-HPLC method for multi-residue analysis of abamectin, emamectin benzoate and ivermectin in rice.

PubMed

Xie, Xianchuan; Gong, Shu; Wang, Xiaorong; Wu, Yinxing; Zhao, Li

2011-01-01

A rapid, reliable and sensitive reverse-phase high-performance liquid chromatography method with fluorescence detection (RP-FLD-HPLC) was developed and validated for simultaneous analysis of the abamectin (ABA), emamectin (EMA) benzoate and ivermectin (IVM) residues in rice. After extraction with acetonitrile/water (2 : 1) with sonication, the avermectin (AVMs) residues were directly derivatised by N-methylimidazole (N-NMIM) and trifluoroacetic anhydride (TFAA) and then analysed on RP-FLD-HPLC. A good linear relationship (r(2 )> 0.99) was obtained for three AVMs ranging from 0.01 to 5 microg ml(-1), i.e. 0.01-5.0 microg g(-1) in rice matrix. The limit of detection (LOD) and the limit of quantification (LOQ) were between 0.001 and 0.002 microg g(-1) and between 0.004 and 0.006 microg g(-1), respectively. Recoveries were from 81.9% to 105.4% and precision less than 12.4%. The proposed method was successfully applied to routine analysis of the AVMs residues in rice.

Size assessment of breast lesions by means of a computer-aided detection (CAD) system for magnetic resonance mammography.

PubMed

Levrini, G; Sghedoni, R; Mori, C; Botti, A; Vacondio, R; Nitrosi, A; Iori, M; Nicoli, F

2011-10-01

The aim of this study was to investigate the efficacy of a dedicated software tool for automated volume measurement of breast lesions in contrast-enhanced (CE) magnetic resonance mammography (MRM). The size of 52 breast lesions with a known histopathological diagnosis (three benign, 49 malignant) was automatically evaluated using different techniques. The volume of all lesions was measured automatically (AVM) from CE 3D MRM examinations by means of a computer-aided detection (CAD) system and compared with the size estimates based on maximum diameter measurement (MDM) on MRM, ultrasonography (US), mammography and histopathology. Compared with histopathology as the reference method, AVM understimated lesion size by 4% on average. This result was similar to MDM (3% understimation, not significantly different) but significantly better than US and mammographic lesion measurements (24% and 33% size underestimation, respectively). AVM is as accurate as MDM but faster. Both methods are more accurate for size assessment of breast lesions compared with US and mammography.

Charged-particle stereotactic radiosurgery

NASA Astrophysics Data System (ADS)

Lyman, John T.; Fabrikant, Jacob I.; Frankel, Kenneth A.

1985-05-01

Charged-particle stereotactic radiosurgery is the technique of using accelerated atomic nuclei for the irradiation of a small volume target to a high dose in a short time interval. This is contrasted with conventional radiotherapy where large volumes are treated with many small fractions of photon or electron radiation over a multi-week period. The helium-ion beam used for charged-particle stereotactic radiosurgery at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron is described. This beam is being used for the treatment of inoperable, deep, intracranial arteriovenous malformations (AVMs). Intracranial AVMs are collections of abnormal blood vessels in the brain that may represent a failure of vessels to mature properly and after a long period of slow growth they may produce clinically recognizable neurological symptoms. Based on our experience using narrow beams of helium ions for stereotactic radiosurgical treatment of AVM patients, the characteristics of the treatments are described. Improvements to the technique which are possible by the use of other charged particle beams are discussed.

Rare malformation of glans penis: arteriovenous malformation.

PubMed

Akin, Y; Sarac, M; Yucel, S

2013-01-01

Pediatric glans penis malformations, especially arteriovenous malformations (AVM), are very rare. Herein, we report two rare cases. A 14-year-old boy attended our outpatient clinic with chief complaints of purple swelling and rapidly growing lesion on the glans penis. The lesion was excised surgically after physical and radiological evaluations. Pathology reported AVM and the patient is being followed up. The second case is a 2-year-old boy who was admitted with a big lesion involving glans penis and genital area that has been present since birth. In physical and radiological evaluations, lesion on the glans penis was pulsatile. Parents of the patient did not want any surgery and patient has been in follow-up. Diagnosis of the vascular lesions on glans penis is very easy by physical and radiological examinations today. Long-term follow-up is very important for AVM. Clinicians must make a careful effort to document new glans lesions in the pediatric population and decrease anxiety in the parents of affected children.

Combining data visualization and statistical approaches for interpreting measurements and meta-data: Integrating heatmaps, variable clustering, and mixed regression models

EPA Science Inventory

The advent of new higher throughput analytical instrumentation has put a strain on interpreting and explaining the results from complex studies. Contemporary human, environmental, and biomonitoring data sets are comprised of tens or hundreds of analytes, multiple repeat measures...

Rapid Response to Decision Making for Complex Issues - How Technologies of Cooperation Can Help

DTIC Science & Technology

2005-11-01

creating bottom–up taxonomies—called folksonomies —using metadata tools like del.icio.us (in which users create their own tags for bookmarking Web...tools such as RSS, tagging (and the consequent development of folksonomies ), wikis, and group visualization tools all help multiply the individual

Vispubdata.org: A Metadata Collection About IEEE Visualization (VIS) Publications.

PubMed

Isenberg, Petra; Heimerl, Florian; Koch, Steffen; Isenberg, Tobias; Xu, Panpan; Stolper, Charles D; Sedlmair, Michael; Chen, Jian; Moller, Torsten; Stasko, John

2017-09-01

We have created and made available to all a dataset with information about every paper that has appeared at the IEEE Visualization (VIS) set of conferences: InfoVis, SciVis, VAST, and Vis. The information about each paper includes its title, abstract, authors, and citations to other papers in the conference series, among many other attributes. This article describes the motivation for creating the dataset, as well as our process of coalescing and cleaning the data, and a set of three visualizations we created to facilitate exploration of the data. This data is meant to be useful to the broad data visualization community to help understand the evolution of the field and as an example document collection for text data visualization research.

Gamma Knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part II: Differences in obliteration rates, treatment-obliteration intervals, and prognostic factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicolato, Antonio; Lupidi, Francesco; Section of Sterotactic and Functional Neurosurgery, University of Verona and University Hospital, Verona

2006-03-01

Purpose: To evaluate and compare obliteration rates (OBRs) and treatment-obliteration intervals (TOIs) for cerebral arteriovenous malformations (cAVMs) treated with Gamma Knife radiosurgery in children/adolescents and adults; and to determine factors predicting the OBR and TOI in these two populations. Methods and Materials: This study concerned 62 children/adolescents and 193 adults observed for {>=}3 years. Fisher exact two-tailed and Wilcoxon rank-sum tests, multiple logistics, and Cox proportional hazard models were used for statistical analysis. Results: The overall OBR was 85.5% in children/adolescents and 87.6% in adults (p 0.671), but children/adolescents showed higher 36-month actuarial OBRs (69.35%) and shorter median TOIs (25.7more » months) than adults (66.84% and 28.2 months; p 0.006 and p = 0.017, respectively). In children/adolescents, lower Spetzler-Martin grades (p = 0.043) and younger age (p = 0.019) correlated significantly with OBRs, and lower Spetzler-Martin grades (p 0.024) and noneloquent cAVM locations (p = 0.046) with TOIs. In adults, low flow through the cAVM and <6.2-cm{sup 3} volume were associated with both OBR and TOI (p 0.012 and p = 0.002, respectively). Conclusions: The differences in OBRs within 3 years and TOIs, although slight, seem to show that pediatric cAVMs behave differently from those in adults after Gamma Knife radiosurgery.« less

Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Picel, Andrew C., E-mail: apicel@ucsd.edu; Koo, Sonya J.; Roberts, Anne C.

PurposeThe purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs).Materials and methodsA retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80 %) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20 %) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80 %) and gelatinmore » sponge in one procedure (20 %).ResultsEmbolization resulted in angiographic stasis of flow in all seven procedures. Four women (80 %) presented with vaginal bleeding which was improved after treatment. One woman returned 24 days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60 %) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60 %) had pregnancies and deliveries after embolization.ConclusionsTAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.« less

Embolization of peripheral high-flow arteriovenous malformations with Onyx.

PubMed

Saeed Kilani, M; Lepennec, V; Petit, P; Magalon, G; Casanova, D; Bartoli, J-M; Vidal, V

2017-03-01

The aim of this study was to report our experience in embolization of high flow peripheral arteriovenous malformations (AVMs) with Onyx. Nineteen patients (10 men, 9 women) with peripheral high-flow AVMs who were treated with arteruial embolization using Onyx were retrospectively included. AVMs were located in the head and neck (6), extremities (5), chest (2), kidney (2), uterus (2), pelvis (1) and parietal (1). In 13 patients, embolization was done using Onyx only. One patient underwent embolization by direct puncture, the others by transarterial approach. Embolization was performed in one or multiple sessions (up to 5). A total of 28 sessions were performed. Follow-up was performed with a delay between 10 and 34 months. Technical success was achieved in all patients. Complete devascularization was obtained in 12 patients. Surgical excision was performed in 9 patients. Non-target Onyx embolization was not observed. One patient developed stroke. In 1 patient microcatheter fracture occured. One patient presented severe pain and bradycardia during the procedure that disappeared shortly after. One patient had persistent but less frequent epistaxis after embolization. Another patient had persistent pain without improvement. One patient was lost to follow-up. Other patients were free of symptoms on follow-up. Embolization with Onyx ® is an interesting option for management of peripheral high-flow AVMs either preoperatively or as a single treatment. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Liquid Embolic Agents for Endovascular Embolization: Evaluation of an Established (Onyx) and a Novel (PHIL) Embolic Agent in an In Vitro AVM Model.

PubMed

Vollherbst, D F; Sommer, C M; Ulfert, C; Pfaff, J; Bendszus, M; Möhlenbruch, M A

2017-07-01

Embolization plays a key role in the treatment of arteriovenous malformations. The aim of this study was to evaluate an established (Onyx) and a novel (precipitating hydrophobic injectable liquid [PHIL]) liquid embolic agent in an in vitro AVM model. An AVM model was integrated into a circuit system. The artificial nidus (subdivided into 28 honeycomb-like sections) was embolized with Onyx 18 (group Onyx; n = 8) or PHIL 25 (group PHIL; n = 8) with different pause times between the injections (30 and 60 seconds, n = 4 per study group) by using a 1.3F microcatheter. Procedure times, number of injections, embolization success (defined as the number of filled sections of the artificial nidus), volume of embolic agent, and frequency and extent of reflux and draining vein embolization were assessed. Embolization success was comparable between Onyx and PHIL. Shorter pause times resulted in a significantly higher embolization success for PHIL (median embolization score, 28 versus 18; P = .011). Compared with Onyx, lower volumes of PHIL were required for the same extent of embolization (median volume per section of the artificial nidus, 15.5 versus 3.6 μL; P < .001). While the embolization success was comparable for Onyx and PHIL, pause time had a considerable effect on the embolization success in an in vitro AVM model. Compared with Onyx, lower volumes of PHIL were required for the same extent of embolization. © 2017 by American Journal of Neuroradiology.

Development, validation, and application of a method for selected avermectin determination in rural waters using high performance liquid chromatography and fluorescence detection.

PubMed

Lemos, Maria Augusta Travassos; Matos, Camila Alves; de Resende, Michele Fabri; Prado, Rachel Bardy; Donagemma, Raquel Andrade; Netto, Annibal Duarte Pereira

2016-11-01

Avermectins (AVM) are macrocyclic lactones used in livestock and agriculture. A quantitative method of high performance liquid chromatography with fluorescence detection for the determination of eprinomectin, abamectin, doramectin and ivermectin in rural water samples was developed and validated. The method was employed to study samples collected in the Pito Aceso River microbasin, located in the Bom Jardim municipality, Rio de Janeiro State, Brazil. Samples were extracted by solid phase extraction using a polymeric stationary phase, the eluted fraction was re-concentrated under a gentle N2 flow and derivatized to allow AVM determination using liquid chromatography with fluorescence detection. The excitation and emission wavelengths of the derivatives were 365 and 470nm, respectively, and a total chromatographic run of 12min was achieved. Very low limits of quantification (22-58ngL(-1)) were found after re-concentration using N2. Recovery values varied from 85.7% to 119.2% with standard deviations between 1.2% and 10.2%. The validated method was applied in the determination of AVM in 15 water samples collected in the Pito Aceso River microbasin, but most of them were free of AVM or showed only trace levels of these compounds, except for a sample that contained doramectin (9.11µgL(-1)). The method is suitable for routine analysis with satisfactory recovery, sensitivity, and selectivity. Copyright © 2016 Elsevier Inc. All rights reserved.

Rescue N-butyl-2 cyanoacrylate embolectomy using a Solitaire FR device after venous glue migration during arteriovenous malformation embolization: technical note.

PubMed

Fahed, Robert; Clarençon, Frédéric; Sourour, Nader-Antoine; Chauvet, Dorian; Le Jean, Lise; Chiras, Jacques; Di Maria, Federico

2016-07-01

One of the procedural risks in arteriovenous malformation (AVM) embolization is possible migration of the embolic agent into the venous drainage with an incomplete nidus occlusion, which may lead to severe hemorrhagic complications. This report presents the case of a 29-year-old man who presented with a deep intraparenchymal hematoma on the left side secondary to the spontaneous rupture of a claustral AVM. Upon resorption of the hematoma, the patient underwent an initial therapeutic session of N-butyl-2 cyanoacrylate endovascular embolization, with the purpose of reducing the AVM volume and flow before performing Gamma Knife radiosurgery. After glue injection into one of the arterial feeders, the control angiography showed a partial migration of the glue cast into the straight sinus, with most of the nidus still visible. Because of the bleeding risk due to possible venous hypertension, it was decided to try to retrieve the glue from the vein by using a stent retriever via jugular access. This maneuver allowed a nearly complete removal of the glue cast, thereby restoring normal venous flow drainage. The patient showed no clinical worsening after the procedure. To the authors' knowledge, this is the first report of the use of the Solitaire FR device as a rescue glue retriever. This method should be considered by physicians in cases of unintended glue migration into the venous circulation during AVM embolization.

Statistical methods for clinical verification of dose response parameters related to esophageal stricture and AVM obliteration from radiotherapy

NASA Astrophysics Data System (ADS)

Mavroidis, Panayiotis; Lind, Bengt K.; Theodorou, Kyriaki; Laurell, Göran; Fernberg, Jan-Olof; Lefkopoulos, Dimitrios; Kappas, Constantin; Brahme, Anders

2004-08-01

The purpose of this work is to provide some statistical methods for evaluating the predictive strength of radiobiological models and the validity of dose-response parameters for tumour control and normal tissue complications. This is accomplished by associating the expected complication rates, which are calculated using different models, with the clinical follow-up records. These methods are applied to 77 patients who received radiation treatment for head and neck cancer and 85 patients who were treated for arteriovenous malformation (AVM). The three-dimensional dose distribution delivered to esophagus and AVM nidus and the clinical follow-up results were available for each patient. Dose-response parameters derived by a maximum likelihood fitting were used as a reference to evaluate their compatibility with the examined treatment methodologies. The impact of the parameter uncertainties on the dose-response curves is demonstrated. The clinical utilization of the radiobiological parameters is illustrated. The radiobiological models (relative seriality and linear Poisson) and the reference parameters are validated to prove their suitability in reproducing the treatment outcome pattern of the patient material studied (through the probability of finding a worse fit, area under the ROC curve and khgr2 test). The analysis was carried out for the upper 5 cm of the esophagus (proximal esophagus) where all the strictures are formed, and the total volume of AVM. The estimated confidence intervals of the dose-response curves appear to have a significant supporting role on their clinical implementation and use.

Factors predicting language lateralization in patients with perisylvian vascular malformations

PubMed Central

Lee, Darrin J.; Pouratian, Nader; Bookheimer, Susan Y.; Martin, Neil A.

2017-01-01

Object The authors conducted a study to determine the factors associated with right-sided language dominance in patients with cerebrovascular malformations. Methods Twenty-two patients with either arteriovenous malformations (AVMs [15 cases]) or cavernous malformations (7 cases) underwent functional MR (fMR) imaging studies of language function; a 3.0-T head-only unit was used. Lateralization indices were calculated separately for Broca and Wernicke areas. Lesion size, Spetzler-Martin grade, and the distance between the lesion and anatomically defined language cortex were calculated for each patient. Results Right-sided language dominance occurred in 5 patients, all of whom had AVMs within 10 mm of canonical language areas. Three patients had right-sided language dominance in the Wernicke area alone whereas 2 had right-sided language dominance in both Broca and Wernicke areas. Wada testing and intraoperative electrocortical stimulation were performed as clinically indicated to corroborate fMR imaging findings. Conclusions The primary factor associated with right-sided language dominance was the AVM being within 10 mm of anatomically defined language areas. The lesion size and the Spetzler-Martin grade were not significant factors. Anomalous fMR imaging laterality was typically confined to the language area proximate to the lesion, with the distal language area remaining in the left hemisphere dominant. This study emphasizes the need to map each case individually in patients with left perisylvian AVMs. Assumptions about eloquent cortex based on anatomical landmarks (a key component of Spetzler-Martin grading) may have to be reconsidered. PMID:20302390

World first in high level waste vitrification - A review of French vitrification industrial achievements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brueziere, J.; Chauvin, E.; Piroux, J.C.

2013-07-01

AREVA has more than 30 years experience in operating industrial HLW (High Level radioactive Waste) vitrification facilities (AVM - Marcoule Vitrification Facility, R7 and T7 facilities). This vitrification technology was based on borosilicate glasses and induction-heating. AVM was the world's first industrial HLW vitrification facility to operate in-line with a reprocessing plant. The glass formulation was adapted to commercial Light Water Reactor fission products solutions, including alkaline liquid waste concentrates as well as platinoid-rich clarification fines. The R7 and T7 facilities were designed on the basis of the industrial experience acquired in the AVM facility. The AVM vitrification process wasmore » implemented at a larger scale in order to operate the R7 and T7 facilities in-line with the UP2 and UP3 reprocessing plants. After more than 30 years of operation, outstanding record of operation has been established by the R7 and T7 facilities. The industrial startup of the CCIM (Cold Crucible Induction Melter) technology with enhanced glass formulation was possible thanks to the close cooperation between CEA and AREVA. CCIM is a water-cooled induction melter in which the glass frit and the waste are melted by direct high frequency induction. This technology allows the handling of highly corrosive solutions and high operating temperatures which permits new glass compositions and a higher glass production capacity. The CCIM technology has been implemented successfully at La Hague plant.« less

GeoViQua: quality-aware geospatial data discovery and evaluation

NASA Astrophysics Data System (ADS)

Bigagli, L.; Papeschi, F.; Mazzetti, P.; Nativi, S.

2012-04-01

GeoViQua (QUAlity aware VIsualization for the Global Earth Observation System of Systems) is a recently started FP7 project aiming at complementing the Global Earth Observation System of Systems (GEOSS) with rigorous data quality specifications and quality-aware capabilities, in order to improve reliability in scientific studies and policy decision-making. GeoViQua main scientific and technical objective is to enhance the GEOSS Common Infrastructure (GCI) providing the user community with innovative quality-aware search and evaluation tools, which will be integrated in the GEO-Portal, as well as made available to other end-user interfaces. To this end, GeoViQua will promote the extension of the current standard metadata for geographic information with accurate and expressive quality indicators, also contributing to the definition of a quality label (GEOLabel). GeoViQua proposed solutions will be assessed in several pilot case studies covering the whole Earth Observation chain, from remote sensing acquisition to data processing, to applications in the main GEOSS Societal Benefit Areas. This work presents the preliminary results of GeoViQua Work Package 4 "Enhanced geo-search tools" (WP4), started in January 2012. Its major anticipated technical innovations are search and evaluation tools that communicate and exploit data quality information from the GCI. In particular, GeoViQua will investigate a graphical search interface featuring a coherent and meaningful aggregation of statistics and metadata summaries (e.g. in the form of tables, charts), thus enabling end users to leverage quality constraints for data discovery and evaluation. Preparatory work on WP4 requirements indicated that users need the "best" data for their purpose, implying a high degree of subjectivity in judgment. This suggests that the GeoViQua system should exploit a combination of provider-generated metadata (objective indicators such as summary statistics), system-generated metadata (contextual/tracking information such as provenance of data and metadata), and user-generated metadata (informal user comments, usage information, rating, etc.). Moreover, metadata should include sufficiently complete access information, to allow rich data visualization and propagation. The following main enabling components are currently identified within WP4: - Quality-aware access services, e.g. a quality-aware extension of the OGC Sensor Observation Service (SOS-Q) specification, to support quality constraints for sensor data publishing and access; - Quality-aware discovery services, namely a quality-aware extension of the OGC Catalog Service for the Web (CSW-Q), to cope with quality constrained search; - Quality-augmentation broker (GeoViQua Broker), to support the linking and combination of the existing GCI metadata with GeoViQua- and user-generated metadata required to support the users in selecting the "best" data for their intended use. We are currently developing prototypes of the above quality-enabled geo-search components, that will be assessed in a sensor-based pilot case study in the next months. In particular, the GeoViQua Broker will be integrated with the EuroGEOSS Broker, to implement CSW-Q and federate (either via distribution or harvesting schemes) quality-aware data sources, GeoViQua will constitute a valuable test-bed for advancing the current best practices and standards in geospatial quality representation and exploitation. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n° 265178.

3D mapping of existing observing capabilities in the frame of GAIA-CLIM H2020 project

NASA Astrophysics Data System (ADS)

Emanuele, Tramutola; Madonna, Fabio; Marco, Rosoldi; Francesco, Amato

2017-04-01

The aim of the Gap Analysis for Integrated Atmospheric ECV CLImate Monitoring (GAIA-CLIM) project is to improve our ability to use ground-based and sub-orbital observations to characterise satellite observations for a number of atmospheric Essential Climate Variables (ECVs). The key outcomes will be a "Virtual Observatory" (VO) facility of co-locations and their uncertainties and a report on gaps in capabilities or understanding, which shall be used to inform subsequent Horizon 2020 activities. In particular, Work Package 1 (WP1) of the GAIA-CLIM project is devoted to the geographical mapping of existing non-satellite measurement capabilities for a number of ECVs in the atmospheric, oceanic and terrestrial domains. The work carried out within WP1 has allowed to provide the users with an up-to-date geographical identification, at the European and global scales, of current surface-based, balloon-based and oceanic (floats) observing capabilities on an ECV by ECV basis for several parameters which can be obtained using space-based observations from past, present and planned satellite missions. Having alighted on a set of metadata schema to follow, a consistent collection of discovery metadata has been provided into a common structure and will be made available to users through the GAIA-CLIM VO in 2018. Metadata can be interactively visualized through a 3D Graphical User Interface. The metadataset includes 54 plausible networks and 2 aircraft permanent infrastructures for EO Characterisation in the context of GAIA-CLIM currently operating on different spatial domains and measuring different ECVs using one or more measurement techniques. Each classified network has in addition been assessed for suitability against metrological criteria to identifyy those with a level of maturity which enables closure on a comparison with satellite measurements. The metadata GUI is based on Cesium, a virtual globe freeware and open source written in Javascript. It allows users to apply different filters to the data displayed on the globe, selecting data per ECV, network, measurements type and level of maturity. Filtering is operated with a query to GeoServer web application through the WFS interface on a data layer configured on our DB Postgres with PostGIS extension; filters set on the GUI are expressed using ECQL (Extended Common Query Language). The GUI allows to visualize in real-time the current non-satellite observing capabilities along with the satellite platforms measuring the same ECVs. Satellite ground track and footprint of the instruments on board can be also visualized. This work contributes to improve metadata and web map services and to facilitate users' experience in the spatio-temporal analysis of Earth Observation data.

Separation of Arylenevinylene Macrocycles with a Surface-Confined Two-Dimensional Covalent Organic Framework.

PubMed

Liu, Chunhua; Park, Eunsol; Jin, Yinghua; Liu, Jie; Yu, Yanxia; Zhang, Wei; Lei, Shengbin; Hu, Wenping

2018-05-31

A two-dimensional surface covalent organic framework, prepared by a surface-confined synthesis using 4,4'-azodianiline and benzene-1,3,5-tricarbaldehyde as the precursors, was used as a host network to effectively immobilize arylenevinylene macrocycles (AVMs). Thus AVMs could be separated from their linear polymer analogues, which are the common side-products in the cyclooligomerization process. Scanning tunneling microscopy investigations revealed efficient removal of linear polymers by a simple surface binding and solvent washing process. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Renal arteriovenous malformation: an unusual cause of recurrent haematuria

PubMed Central

Ali, Mazhar; Aziz, Wajahat; Abbas, Farhat

2013-01-01

A 54-year-old woman presented with gross painless haematuria. Initial workup showed no abnormality except mild hydronephrosis on CT scan. Cystoscopy and retrograde pyelography did not find any gross lesion and her urine cytology was also negative. She had recurrent haematuria so her CT was reviewed with the radiologist with clinical suspicion of arteriovenous malformation (AVM) which was suggested by relatively increased contrast density in the hemiazygous vein and renal vein in the arterial phase. She underwent angioembiolisation of left renal AVM after which her haematuria settled. PMID:23867881

Study on Information Management for the Conservation of Traditional Chinese Architectural Heritage - 3d Modelling and Metadata Representation

NASA Astrophysics Data System (ADS)

Yen, Y. N.; Weng, K. H.; Huang, H. Y.

2013-07-01

After over 30 years of practise and development, Taiwan's architectural conservation field is moving rapidly into digitalization and its applications. Compared to modern buildings, traditional Chinese architecture has considerably more complex elements and forms. To document and digitize these unique heritages in their conservation lifecycle is a new and important issue. This article takes the caisson ceiling of the Taipei Confucius Temple, octagonal with 333 elements in 8 types, as a case study for digitization practise. The application of metadata representation and 3D modelling are the two key issues to discuss. Both Revit and SketchUp were appliedin this research to compare its effectiveness to metadata representation. Due to limitation of the Revit database, the final 3D models wasbuilt with SketchUp. The research found that, firstly, cultural heritage databasesmustconvey that while many elements are similar in appearance, they are unique in value; although 3D simulations help the general understanding of architectural heritage, software such as Revit and SketchUp, at this stage, could onlybe used tomodel basic visual representations, and is ineffective indocumenting additional critical data ofindividually unique elements. Secondly, when establishing conservation lifecycle information for application in management systems, a full and detailed presentation of the metadata must also be implemented; the existing applications of BIM in managing conservation lifecycles are still insufficient. Results of the research recommends SketchUp as a tool for present modelling needs, and BIM for sharing data between users, but the implementation of metadata representation is of the utmost importance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bush, Brian W; Brunhart-Lupo, Nicholas J; Gruchalla, Kenny M

This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bush, Brian W; Brunhart-Lupo, Nicholas J; Gruchalla, Kenny M

This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

Network Access to Visual Information: A Study of Costs and Uses.

ERIC Educational Resources Information Center

Besser, Howard

This paper summarizes a subset of the findings of a study of digital image distribution that focused on the Museum Educational Site Licensing (MESL) project--the first large-scale multi-institutional project to explore digital delivery of art images and accompanying text/metadata from disparate sources. This Mellon Foundation-sponsored study…

Genetic variation in the functional ENG allele inherited from the non-affected parent associates with presence of pulmonary arteriovenous malformation in hereditary hemorrhagic telangiectasia 1 (HHT1) and may influence expression of PTPN14.

PubMed

Letteboer, Tom G W; Benzinou, Michael; Merrick, Christopher B; Quigley, David A; Zhau, Kechen; Kim, Il-Jin; To, Minh D; Jablons, David M; van Amstel, Johannes K P; Westermann, Cornelius J J; Giraud, Sophie; Dupuis-Girod, Sophie; Lesca, Gaetan; Berg, Jonathan H; Balmain, Allan; Akhurst, Rosemary J

2015-01-01

HHT shows clinical variability within and between families. Organ site and prevalence of arteriovenous malformations (AVMs) depend on the HHT causative gene and on environmental and genetic modifiers. We tested whether variation in the functional ENG allele, inherited from the unaffected parent, alters risk for pulmonary AVM in HHT1 mutation carriers who are ENG haploinsufficient. Genetic association was found between rs10987746 of the wild type ENG allele and presence of pulmonary AVM [relative risk = 1.3 (1.0018-1.7424)]. The rs10987746-C at-risk allele associated with lower expression of ENG RNA in a panel of human lymphoblastoid cell lines (P = 0.004). Moreover, in angiogenically active human lung adenocarcinoma tissue, but not in uninvolved quiescent lung, rs10987746-C was correlated with expression of PTPN14 (P = 0.004), another modifier of HHT. Quantitative TAQMAN expression analysis in a panel of normal lung tissues from 69 genetically heterogeneous inter-specific backcross mice, demonstrated strong correlation between expression levels of Eng, Acvrl1, and Ptpn14 (r2 = 0.75-0.9, P < 1 × 10(-12)), further suggesting a direct or indirect interaction between these three genes in lung in vivo. Our data indicate that genetic variation within the single functional ENG gene influences quantitative and/or qualitative differences in ENG expression that contribute to risk of pulmonary AVM in HHT1, and provide correlative support for PTPN14 involvement in endoglin/ALK1 lung biology in vivo. PTPN14 has been shown to be a negative regulator of Yap/Taz signaling, which is implicated in mechanotransduction, providing a possible molecular link between endoglin/ALK1 signaling and mechanical stress. EMILIN2, which showed suggestive genetic association with pulmonary AVM, is also reported to interact with Taz in angiogenesis. Elucidation of the molecular mechanisms regulating these interactions in endothelial cells may ultimately provide more rational choices for HHT therapy.

Relief of epilepsy and headache and quality of life after microsurgical treatment of unruptured brain AVM-audit of a single-center series and comprehensive review of the literature.

PubMed

Rohn, Benjamin; Hänggi, Daniel; Etminan, Nima; Turowski, Bernd; Steiger, Hans-Jakob

2017-01-01

Although the benefit of intervention for unruptured arteriovenous malformation (AVM) with regard to stroke rates and long-term disability remains unclear, most patients present with symptoms, such as epilepsy, headache, or neurological deficits, compromising their quality of life. Detailed analysis of the long-term effects of microsurgical treatment on quality of life, epilepsy, and headache was the purpose of this audit. A series of 25 microsurgically treated patients were interviewed on average 7 ± 5 years after treatment. Detailed information was obtained regarding frequency and severity of seizures and headaches. Outcome data was compared with the initial complaints and neurological findings. The Short Form (SF)-36 was used to assess health-related quality of life. On average, the SF-36 scores did not differ significantly from the age-matched German norm values. Patients suffering from chronic headache prior to treatment scored worse in most SF-36 subscales than patients without headache at the time of treatment, and the difference was significant in the SF-36 dimensions physical role functioning and emotional role functioning (P = 0.04). In contrast, there was a trend for patients treated for incidental AVM to score somewhat better than the age norm. Twelve patients had been admitted with epilepsy. At the time of follow-up, all patients were seizure free (Engel class I), although 7 of them continued to take antiepileptic medication. Two of 13 patients without epilepsy at the time of treatment experienced seizures sometime during the post treatment course and were under medication at the time of long-term follow-up interview. At the time of the audit, 7 of 11 patients admitted with chronic headache necessitating regular use of pain medication indicated not to use pain medication any longer. Our data suggest that initial symptoms leading to diagnosis and treatment of unruptured AVM may influence long-term quality of life following treatment. Patients admitted with headache as the chief complaint appear to fare worse than patients with epileptogenic or incidental AVMs.

Planning Evaluation of C-Arm Cone Beam CT Angiography for Target Delineation in Stereotactic Radiation Surgery of Brain Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Jun; Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland; Huang, Judy

Purpose: Stereotactic radiation surgery (SRS) is one of the therapeutic modalities currently available to treat cerebral arteriovenous malformations (AVM). Conventionally, magnetic resonance imaging (MRI) and MR angiography (MRA) and digital subtraction angiography (DSA) are used in combination to identify the target volume for SRS treatment. The purpose of this study was to evaluate the use of C-arm cone beam computed tomography (CBCT) in the treatment planning of SRS for cerebral AVMs. Methods and Materials: Sixteen consecutive patients treated for brain AVMs at our institution were included in this retrospective study. Prior to treatment, all patients underwent MRA, DSA, and C-arm CBCT.more » All images were coregistered using the GammaPlan planning system. AVM regions were delineated independently by 2 physicians using either C-arm CBCT or MRA, resulting in 2 volumes: a CBCT volume (VCBCT) and an MRA volume (V{sub MRA}). SRS plans were generated based on the delineated regions. Results: The average volume of treatment targets delineated using C-arm CBCT and MRA were similar, 6.40 cm{sup 3} and 6.98 cm{sup 3}, respectively (P=.82). However, significant regions of nonoverlap existed. On average, the overlap of the MRA with the C-arm CBCT was only 52.8% of the total volume. In most cases, radiation plans based on V{sub MRA} did not provide adequate dose to the region identified on C-arm CBCT; the mean minimum dose to V{sub CBCT} was 29.5%, whereas the intended goal was 45% (P<.001). The mean volume of normal brain receiving 12 Gy or more in C-arm CBCT-based plans was not greater than in the MRA-based plans. Conclusions: Use of C-arm CBCT images significantly alters the delineated regions of AVMs for SRS planning, compared to that of MRA/MRI images. CT-based planning can be accomplished without increasing the dose to normal brain and may represent a more accurate definition of the nidus, increasing the chances for successful obliteration.« less

Is a Swine Model of Arteriovenous Malformation Suitable for Human Extracranial Arteriovenous Malformation? A Preliminary Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lv, Ming-ming, E-mail: lvmingming001@163.com; Fan, Xin-dong, E-mail: fanxindong@yahoo.com.cn; Su, Li-xin, E-mail: sulixin1975@126.com

Objective: A chronic arteriovenous malformation (AVM) model using the swine retia mirabilia (RMB) was developed and compared with the human extracranial AVM (EAVM) both in hemodynamics and pathology, to see if this brain AVM model can be used as an EAVM model. Methods: We created an arteriovenous fistula between the common carotid artery and the external jugular vein in eight animals by using end-to-end anastomosis. All animals were sacrificed 1 month after surgery, and the bilateral retia were obtained at autopsy and performed hematoxylin and eosin staining and immunohistochemistry. Pre- and postsurgical hemodynamic evaluations also were conducted. Then, the bloodmore » flow and histological changes of the animal model were compared with human EAVM. Results: The angiography after operation showed that the blood flow, like human EAVM, flowed from the feeding artery, via the nidus, drained to the draining vein. Microscopic examination showed dilated lumina and disrupted internal elastic lamina in both RMB of model and nidus of human EAVM, but the thickness of vessel wall had significant difference. Immunohistochemical reactivity for smooth muscle actin, angiopoietin 1, and angiopoietin 2 were similar in chronic model nidus microvessels and human EAVM, whereas vascular endothelial growth factor was significant difference between human EAVM and RMB of model. Conclusions: The AVM model described here is similar to human EAVM in hemodynamics and immunohistochemical features, but there are still some differences in anatomy and pathogenetic mechanism. Further study is needed to evaluate the applicability and efficacy of this model.« less

Hydrazine monitoring in spacecraft

NASA Technical Reports Server (NTRS)

Cross, J. H.; Beck, S. W.; Limero, T. F.; James, J. T.

1992-01-01

Hydrazine (HZ) and monomethyl hydrazine (MMH) are highly toxic compounds used as fuels in the Space Shuttle Orbiter Main Engines and in its maneuvering and reaction control system. Satellite refueling during a mission may also result in release of hydrazines. During extravehicular activities, the potential exists for hydrazines to contaminate the suit and to be brought into the internal atmosphere inadvertantly. Because of the high toxicity of hydrazines, a very sensitive, reliable, interference-free, and real-time method of measurement is required. A portable ion mobility spectrometer (IMS) has exhibited a low ppb detection limit for hydrazines suggesting a promising technology for the detection of hydrazines in spacecraft air. The Hydrazine Monitor is a modified airborne vapor monitor (AVM) with a custom-built datalogger. This off-the-shelf IMS was developed for the detection of chemical warfare agents on the battlefield. After early evaluations of the AVM for hydrazine measurements showed a serious interference from ammonia, the AVM was modified to measure HZ and MMH in the ppb concentration range without interference from ammonia in the low ppm range. A description of the Hydrazine Monitor and how it functions is presented.

[Severe rhabdomyolysis and intracranial hemorrhage associated with synthetic cannabinoid: a case report].

PubMed

Tanei, Takafumi; Morita, Yoshiki; Yashima, Akihito; Wakita, Hiroyuki; Takebayashi, Shigenori; Nakahara, Norimoto; Wakabayashi, Toshihiko

2014-09-01

A 28-year-old male presented with language and behavior disorders a few days prior to examination. Magnetic resonance images and cerebral angiography revealed an arteriovenous malformation (AVM) in the right frontal lobe. The size of the nidus was 2.0 cm, and it was fed by the middle cerebral arteries and drained by the superior sagittal and transverse sinuses. The AVM was completely surgically resected without any complications. Ten months after the surgery, the patient presented with behavior disorders again and general convulsion. Computed tomography showed a small intracranial hemorrhage at the right frontal lobe, where the AVM was located. Blood examination revealed severe rhabdomyolysis (CK:536,620U/L)and acute kidney injury (Cr:5.20mg/dL). After admission, it became clear that the patient had used synthetic cannabinoid (SC). SC refers to a variety of herbal/chemical mixtures, which mimic the effects of marijuana. Little data is available on the psychopathological and physical effects of SC. This is the first report of severe rhabdomyolysis and intracranial hemorrhage associated with SC use in Japan.

Automated sea floor extraction from underwater video

NASA Astrophysics Data System (ADS)

Kelly, Lauren; Rahmes, Mark; Stiver, James; McCluskey, Mike

2016-05-01

Ocean floor mapping using video is a method to simply and cost-effectively record large areas of the seafloor. Obtaining visual and elevation models has noteworthy applications in search and recovery missions. Hazards to navigation are abundant and pose a significant threat to the safety, effectiveness, and speed of naval operations and commercial vessels. This project's objective was to develop a workflow to automatically extract metadata from marine video and create image optical and elevation surface mosaics. Three developments made this possible. First, optical character recognition (OCR) by means of two-dimensional correlation, using a known character set, allowed for the capture of metadata from image files. Second, exploiting the image metadata (i.e., latitude, longitude, heading, camera angle, and depth readings) allowed for the determination of location and orientation of the image frame in mosaic. Image registration improved the accuracy of mosaicking. Finally, overlapping data allowed us to determine height information. A disparity map was created using the parallax from overlapping viewpoints of a given area and the relative height data was utilized to create a three-dimensional, textured elevation map.

Mercury: An Example of Effective Software Reuse for Metadata Management, Data Discovery and Access

NASA Astrophysics Data System (ADS)

Devarakonda, Ranjeet; Palanisamy, Giri; Green, James; Wilson, Bruce E.

2008-12-01

Mercury is a federated metadata harvesting, data discovery and access tool based on both open source packages and custom developed software. Though originally developed for NASA, the Mercury development consortium now includes funding from NASA, USGS, and DOE. Mercury supports the reuse of metadata by enabling searching across a range of metadata specification and standards including XML, Z39.50, FGDC, Dublin-Core, Darwin-Core, EML, and ISO-19115. Mercury provides a single portal to information contained in distributed data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. One of the major goals of the recent redesign of Mercury was to improve the software reusability across the 12 projects which currently fund the continuing development of Mercury. These projects span a range of land, atmosphere, and ocean ecological communities and have a number of common needs for metadata searches, but they also have a number of needs specific to one or a few projects. To balance these common and project-specific needs, Mercury's architecture has three major reusable components; a harvester engine, an indexing system and a user interface component. The harvester engine is responsible for harvesting metadata records from various distributed servers around the USA and around the world. The harvester software was packaged in such a way that all the Mercury projects will use the same harvester scripts but each project will be driven by a set of project specific configuration files. The harvested files are structured metadata records that are indexed against the search library API consistently, so that it can render various search capabilities such as simple, fielded, spatial and temporal. This backend component is supported by a very flexible, easy to use Graphical User Interface which is driven by cascading style sheets, which make it even simpler for reusable design implementation. The new Mercury system is based on a Service Oriented Architecture and effectively reuses components for various services such as Thesaurus Service, Gazetteer Web Service and UDDI Directory Services. The software also provides various search services including: RSS, Geo-RSS, OpenSearch, Web Services and Portlets, integrated shopping cart to order datasets from various data centers (ORNL DAAC, NSIDC) and integrated visualization tools. Other features include: Filtering and dynamic sorting of search results, book- markable search results, save, retrieve, and modify search criteria.

Mercury: An Example of Effective Software Reuse for Metadata Management, Data Discovery and Access

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devarakonda, Ranjeet

2008-01-01

Mercury is a federated metadata harvesting, data discovery and access tool based on both open source packages and custom developed software. Though originally developed for NASA, the Mercury development consortium now includes funding from NASA, USGS, and DOE. Mercury supports the reuse of metadata by enabling searching across a range of metadata specification and standards including XML, Z39.50, FGDC, Dublin-Core, Darwin-Core, EML, and ISO-19115. Mercury provides a single portal to information contained in distributed data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfacesmore » then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. One of the major goals of the recent redesign of Mercury was to improve the software reusability across the 12 projects which currently fund the continuing development of Mercury. These projects span a range of land, atmosphere, and ocean ecological communities and have a number of common needs for metadata searches, but they also have a number of needs specific to one or a few projects. To balance these common and project-specific needs, Mercury's architecture has three major reusable components; a harvester engine, an indexing system and a user interface component. The harvester engine is responsible for harvesting metadata records from various distributed servers around the USA and around the world. The harvester software was packaged in such a way that all the Mercury projects will use the same harvester scripts but each project will be driven by a set of project specific configuration files. The harvested files are structured metadata records that are indexed against the search library API consistently, so that it can render various search capabilities such as simple, fielded, spatial and temporal. This backend component is supported by a very flexible, easy to use Graphical User Interface which is driven by cascading style sheets, which make it even simpler for reusable design implementation. The new Mercury system is based on a Service Oriented Architecture and effectively reuses components for various services such as Thesaurus Service, Gazetteer Web Service and UDDI Directory Services. The software also provides various search services including: RSS, Geo-RSS, OpenSearch, Web Services and Portlets, integrated shopping cart to order datasets from various data centers (ORNL DAAC, NSIDC) and integrated visualization tools. Other features include: Filtering and dynamic sorting of search results, book- markable search results, save, retrieve, and modify search criteria.« less

ODISEES: A New Paradigm in Data Access

NASA Astrophysics Data System (ADS)

Huffer, E.; Little, M. M.; Kusterer, J.

2013-12-01

As part of its ongoing efforts to improve access to data, the Atmospheric Science Data Center has developed a high-precision Earth Science domain ontology (the 'ES Ontology') implemented in a graph database ('the Semantic Metadata Repository') that is used to store detailed, semantically-enhanced, parameter-level metadata for ASDC data products. The ES Ontology provides the semantic infrastructure needed to drive the ASDC's Ontology-Driven Interactive Search Environment for Earth Science ('ODISEES'), a data discovery and access tool, and will support additional data services such as analytics and visualization. The ES ontology is designed on the premise that naming conventions alone are not adequate to provide the information needed by prospective data consumers to assess the suitability of a given dataset for their research requirements; nor are current metadata conventions adequate to support seamless machine-to-machine interactions between file servers and end-user applications. Data consumers need information not only about what two data elements have in common, but also about how they are different. End-user applications need consistent, detailed metadata to support real-time data interoperability. The ES ontology is a highly precise, bottom-up, queriable model of the Earth Science domain that focuses on critical details about the measurable phenomena, instrument techniques, data processing methods, and data file structures. Earth Science parameters are described in detail in the ES Ontology and mapped to the corresponding variables that occur in ASDC datasets. Variables are in turn mapped to well-annotated representations of the datasets that they occur in, the instrument(s) used to create them, the instrument platforms, the processing methods, etc., creating a linked-data structure that allows both human and machine users to access a wealth of information critical to understanding and manipulating the data. The mappings are recorded in the Semantic Metadata Repository as RDF-triples. An off-the-shelf Ontology Development Environment and a custom Metadata Conversion Tool comprise a human-machine/machine-machine hybrid tool that partially automates the creation of metadata as RDF-triples by interfacing with existing metadata repositories and providing a user interface that solicits input from a human user, when needed. RDF-triples are pushed to the Ontology Development Environment, where a reasoning engine executes a series of inference rules whose antecedent conditions can be satisfied by the initial set of RDF-triples, thereby generating the additional detailed metadata that is missing in existing repositories. A SPARQL Endpoint, a web-based query service and a Graphical User Interface allow prospective data consumers - even those with no familiarity with NASA data products - to search the metadata repository to find and order data products that meet their exact specifications. A web-based API will provide an interface for machine-to-machine transactions.

Extensive uterine arteriovenous malformation with hemodynamic instability: Embolization for whole myometrium affection.

PubMed

El Agwany, Ahmed Samy; Elshafei, Mohamed

2018-03-01

Uterine arteriovenous malformation is abnormal and nonfunctional connections between the uterine arteries and veins. Patients typically present with vaginal bleeding which may be life-threatening. Treatment depends on the symptoms, age, desire for future fertility, localization and size of the lesion. Embolization of the uterine artery is the first choice in symptomatic AVM in patients in the reproductive age. We report a case of acquired AVM with an extensive lesion on ultrasound and MRI, which was successfully treated with uterine artery embolization for severe bleeding (UAE). Copyright © 2018 Elsevier B.V. All rights reserved.

Definition of an ISO 19115 metadata profile for SeaDataNet II Cruise Summary Reports and its XML encoding

NASA Astrophysics Data System (ADS)

Boldrini, Enrico; Schaap, Dick M. A.; Nativi, Stefano

2013-04-01

SeaDataNet implements a distributed pan-European infrastructure for Ocean and Marine Data Management whose nodes are maintained by 40 national oceanographic and marine data centers from 35 countries riparian to all European seas. A unique portal makes possible distributed discovery, visualization and access of the available sea data across all the member nodes. Geographic metadata play an important role in such an infrastructure, enabling an efficient documentation and discovery of the resources of interest. In particular: - Common Data Index (CDI) metadata describe the sea datasets, including identification information (e.g. product title, interested area), evaluation information (e.g. data resolution, constraints) and distribution information (e.g. download endpoint, download protocol); - Cruise Summary Reports (CSR) metadata describe cruises and field experiments at sea, including identification information (e.g. cruise title, name of the ship), acquisition information (e.g. utilized instruments, number of samples taken) In the context of the second phase of SeaDataNet (SeaDataNet 2 EU FP7 project, grant agreement 283607, started on October 1st, 2011 for a duration of 4 years) a major target is the setting, adoption and promotion of common international standards, to the benefit of outreach and interoperability with the international initiatives and communities (e.g. OGC, INSPIRE, GEOSS, …). A standardization effort conducted by CNR with the support of MARIS, IFREMER, STFC, BODC and ENEA has led to the creation of a ISO 19115 metadata profile of CDI and its XML encoding based on ISO 19139. The CDI profile is now in its stable version and it's being implemented and adopted by the SeaDataNet community tools and software. The effort has then continued to produce an ISO based metadata model and its XML encoding also for CSR. The metadata elements included in the CSR profile belong to different models: - ISO 19115: E.g. cruise identification information, including title and area of interest; metadata responsible party information - ISO 19115-2: E.g. acquisition information, including date of sampling, instruments used - SeaDataNet: E.g. SeaDataNet community specific, including EDMO and EDMERP code lists Two main guidelines have been followed in the metadata model drafting: - All the obligations and constraints required by both the ISO standards and INSPIRE directive had to be satisfied. These include the presence of specific elements with given cardinality (e.g. mandatory metadata date stamp, mandatory lineage information) - All the content information of legacy CSR format had to be supported by the new metadata model. An XML encoding of the CSR profile has been defined as well. Based on the ISO 19139 XML schema and constraints, it adds the new elements specific of the SeaDataNet community. The associated Schematron rules are used to enforce constraints not enforceable just with the Schema and to validate elements content against the SeaDataNet code lists vocabularies.

Mercury: Reusable software application for Metadata Management, Data Discovery and Access

NASA Astrophysics Data System (ADS)

Devarakonda, Ranjeet; Palanisamy, Giri; Green, James; Wilson, Bruce E.

2009-12-01

Mercury is a federated metadata harvesting, data discovery and access tool based on both open source packages and custom developed software. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. Mercury is itself a reusable toolset for metadata, with current use in 12 different projects. Mercury also supports the reuse of metadata by enabling searching across a range of metadata specification and standards including XML, Z39.50, FGDC, Dublin-Core, Darwin-Core, EML, and ISO-19115. Mercury provides a single portal to information contained in distributed data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. One of the major goals of the recent redesign of Mercury was to improve the software reusability across the projects which currently fund the continuing development of Mercury. These projects span a range of land, atmosphere, and ocean ecological communities and have a number of common needs for metadata searches, but they also have a number of needs specific to one or a few projects To balance these common and project-specific needs, Mercury’s architecture includes three major reusable components; a harvester engine, an indexing system and a user interface component. The harvester engine is responsible for harvesting metadata records from various distributed servers around the USA and around the world. The harvester software was packaged in such a way that all the Mercury projects will use the same harvester scripts but each project will be driven by a set of configuration files. The harvested files are then passed to the Indexing system, where each of the fields in these structured metadata records are indexed properly, so that the query engine can perform simple, keyword, spatial and temporal searches across these metadata sources. The search user interface software has two API categories; a common core API which is used by all the Mercury user interfaces for querying the index and a customized API for project specific user interfaces. For our work in producing a reusable, portable, robust, feature-rich application, Mercury received a 2008 NASA Earth Science Data Systems Software Reuse Working Group Peer-Recognition Software Reuse Award. The new Mercury system is based on a Service Oriented Architecture and effectively reuses components for various services such as Thesaurus Service, Gazetteer Web Service and UDDI Directory Services. The software also provides various search services including: RSS, Geo-RSS, OpenSearch, Web Services and Portlets, integrated shopping cart to order datasets from various data centers (ORNL DAAC, NSIDC) and integrated visualization tools. Other features include: Filtering and dynamic sorting of search results, book-markable search results, save, retrieve, and modify search criteria.

Implementation of an oblique-sectioning visualization tool for line-of-sight stereotactic neurosurgical navigation using the AVW toolkit

NASA Astrophysics Data System (ADS)

Bates, Lisa M.; Hanson, Dennis P.; Kall, Bruce A.; Meyer, Frederic B.; Robb, Richard A.

1998-06-01

An important clinical application of biomedical imaging and visualization techniques is provision of image guided neurosurgical planning and navigation techniques using interactive computer display systems in the operating room. Current systems provide interactive display of orthogonal images and 3D surface or volume renderings integrated with and guided by the location of a surgical probe. However, structures in the 'line-of-sight' path which lead to the surgical target cannot be directly visualized, presenting difficulty in obtaining full understanding of the 3D volumetric anatomic relationships necessary for effective neurosurgical navigation below the cortical surface. Complex vascular relationships and histologic boundaries like those found in artereovenous malformations (AVM's) also contribute to the difficulty in determining optimal approaches prior to actual surgical intervention. These difficulties demonstrate the need for interactive oblique imaging methods to provide 'line-of-sight' visualization. Capabilities for 'line-of- sight' interactive oblique sectioning are present in several current neurosurgical navigation systems. However, our implementation is novel, in that it utilizes a completely independent software toolkit, AVW (A Visualization Workshop) developed at the Mayo Biomedical Imaging Resource, integrated with a current neurosurgical navigation system, the COMPASS stereotactic system at Mayo Foundation. The toolkit is a comprehensive, C-callable imaging toolkit containing over 500 optimized imaging functions and structures. The powerful functionality and versatility of the AVW imaging toolkit provided facile integration and implementation of desired interactive oblique sectioning using a finite set of functions. The implementation of the AVW-based code resulted in higher-level functions for complete 'line-of-sight' visualization.

Explorative visual analytics on interval-based genomic data and their metadata.

PubMed

Jalili, Vahid; Matteucci, Matteo; Masseroli, Marco; Ceri, Stefano

2017-12-04

With the wide-spreading of public repositories of NGS processed data, the availability of user-friendly and effective tools for data exploration, analysis and visualization is becoming very relevant. These tools enable interactive analytics, an exploratory approach for the seamless "sense-making" of data through on-the-fly integration of analysis and visualization phases, suggested not only for evaluating processing results, but also for designing and adapting NGS data analysis pipelines. This paper presents abstractions for supporting the early analysis of NGS processed data and their implementation in an associated tool, named GenoMetric Space Explorer (GeMSE). This tool serves the needs of the GenoMetric Query Language, an innovative cloud-based system for computing complex queries over heterogeneous processed data. It can also be used starting from any text files in standard BED, BroadPeak, NarrowPeak, GTF, or general tab-delimited format, containing numerical features of genomic regions; metadata can be provided as text files in tab-delimited attribute-value format. GeMSE allows interactive analytics, consisting of on-the-fly cycling among steps of data exploration, analysis and visualization that help biologists and bioinformaticians in making sense of heterogeneous genomic datasets. By means of an explorative interaction support, users can trace past activities and quickly recover their results, seamlessly going backward and forward in the analysis steps and comparative visualizations of heatmaps. GeMSE effective application and practical usefulness is demonstrated through significant use cases of biological interest. GeMSE is available at http://www.bioinformatics.deib.polimi.it/GeMSE/ , and its source code is available at https://github.com/Genometric/GeMSE under GPLv3 open-source license.

Acoustic velocity meter systems

USGS Publications Warehouse

Laenen, Antonius

1985-01-01

Acoustic velocity meter (AVM) systems operate on the principles that the point-to-point upstream traveltime of an acoustic pulse is longer than the downstream traveltime and that this difference in traveltime can be accurately measured by electronic devices. An AVM system is capable of recording water velocity (and discharge) under a wide range of conditions, but some constraints apply: 1. Accuracy is reduced and performance is degraded if the acoustic path is not a continuous straight line. The path can be bent by reflection if it is too close to a stream boundary or by refraction if it passes through density gradients resulting from variations in either water temperature or salinity. For paths of less than 100 m, a temperature gradient of 0.1' per meter causes signal bending less than 0.6 meter at midchannel, and satisfactory velocity results can be obtained. Reflection from stream boundaries can cause signal cancellation if boundaries are too close to signal path. 2. Signal strength is attenuated by particles or bubbles that absorb, spread, or scatter sound. The concentration of particles or bubbles that can be tolerated is a function of the path length and frequency of the acoustic signal. 3. Changes in streamline orientation can affect system accuracy if the variability is random. 4. Errors relating to signal resolution are much larger for a single threshold detection scheme than for multiple threshold schemes. This report provides methods for computing the effect of various conditions on the accuracy of a record obtained from an AVM. The equipment must be adapted to the site. Field reconnaissance and preinstallation analysis to detect possible problems are critical for proper installation and operation of an AVM system.

Asystole During Onyx Embolization of a Pediatric Arteriovenous Malformation: A Severe Case of the Trigeminocardiac Reflex.

PubMed

Khatibi, Kasra; Choudhri, Omar; Connolly, Ian D; McTaggart, Ryan A; Do, Huy M

2017-02-01

Trigeminal-cardiac reflex (TCR) from the stimulation of sensory branches of trigeminal nerve can lead to hemodynamic instability. This phenomenon has been described during ophthalmologic, craniofacial, and skull base surgeries. TCR has been reported rarely with endovascular onyx embolization of dural arteriovenous fistulas. We report a case of TCR during endovascular Onyx embolization of an arteriovenous malformation (AVM). A 16-year-old boy presented with a large cerebellar AVM with arterial feeders from the external carotid artery and posterior cerebral artery branches. The middle meningeal artery was catheterized, through which dimethyl sulfoxide was injected, followed by Onyx, into the nidus and the feeders. Near the completion of embolization, patient became bradycardic and proceeded to asystole; he was resuscitated with chest compression, atropine, and vasopressors. We used PubMed to identify the reported cases of Onyx and other endovascular embolizations complicated by hemodynamic instability. We found 16 cases of endovascular onyx embolization complicated by clinically significant hemodynamic changes in the treatment of dural arteriovenous fistula, cavernous carotid fistula, and juvenile nasopharygeal angiofibroma but not with AVMs. In these cases, arterial supply to the nidus involved the sensory receptive field of trigeminal nerve. Hemodynamic changes have been reported during the injection of dimethyl sulfoxide before the introduction of Onyx, as well as Onyx injection and cast formation. TCR can lead to significant hemodynamic changes during endovascular Onyx embolization of vascular malformations (both pial AVM and dural arteriovenous fistulas) involving receptive field of trigeminal nerve. Therefore, the anesthesiologist should be made aware of treatment approach before intervention and appropriate precautions taken. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors Determining the Clinical Complications of Radiosurgery for AVM.

PubMed

Machnowska, Matylda; Taeshineetanakul, Patamintita; Geibprasert, Sasikhan; Menezes, Ravi; Agid, Ronit; Terbrugge, Karel G; Andrade-Souza, Yuri; Schwartz, Michael L; Krings, Timo

2013-11-01

To identify the predictors of symptomatic post-radiation T2 signal change in patients with arteriovenous malformations (AVM) treated with radiosurgery. The charts of 211 consecutive patients with arteriovenous malformations treated with either gamma knife radisurgery or linear accelerator radiosurgery between 2000-2009 were retrospectively reviewed. 168 patients had a minimum of 12 months of clinical and radiologic follow-up following the procedure and complete dosage data. Pretreatment characteristics and dosimetric variables were analyzed to identify predictors of adverse radiation effects. 141 patients had no clinical symptomatic complications. 21 patients had global or focal neurological deficits attributed to symptomatic edema. Variables associated with development of symptomatic edema included a non-hemorrhagic symptomatic presentation compared to presentation with hemorrhage, p=0.001; OR (95%CI) = 6.26 (1.99, 19.69); the presence of venous rerouting compared to the lack of venous rerouting, p=0.031; OR (95% CI) = 3.25 (1.20, 8.80); radiosurgery with GKS compared to linear accelerator radiosurgery p = 0.012; OR (95% CI) = 4.58 (1.28, 16.32); and the presence of more than one draining vein compared to a single draining vein p = 0.032; OR (95% CI) = 2.82 (1.06, 7.50). We postulated that the higher maximal doses used with gamma knife radiosurgery may be responsible for the greater number of adverse radiation effects with this modality compared to linear accelerator radiosurgery. We found that AVMs with greater venous complexity and therefore instability resulted in more adverse treatment outcomes, suggesting that AVM angioarchitecture should be considered when making treatment decisions. Facteurs en cause dans les complications cliniques de la radiochirurgie pour une malformation artérioveineuse.

Does Right-Sided Language Lateralization on BOLD-fMRI Affect Postoperative Language Outcome for AVM Patients?

PubMed

Liu, Zhi; Deng, Xiaofeng; Cao, Yong; Zhao, Yuanli; Zhao, Jizong; Wang, Shuo

2017-01-01

For cerebral arteriovenous malformations (AVMs) involving language areas, right-sided language lateralization on functional magnetic resonance imaging (fMRI) has been reported, which is regarded as language cortex reorganization. The authors attempted to study if this right-sided language lateralization affects postoperative language outcome. Clinical and imaging data of 43 right-handed AVM patients who underwent preoperative fMRI were retrospectively reviewed. All lesions involved the language cortex, with the Broca area involved in 13 patients and the Wernicke area involved in 30 patients. Lateralization indices (LI) of BOLD signal activations were calculated to determine language lateralization. All patients underwent craniotomy and total resection. Western aphasia battery (WAB) was used to evaluate language functions preoperatively, 1-2 weeks after surgery and 6-30 months after surgery. On preoperative fMRI, right-sided lateralization was observed in 18 patients (41.9%, R Group), including 3 with rightsided lateralization in the Broca area alone, 14 in the Wernicke area alone, and 1 in both areas. The other 25 patients were non-rightsided lateralized (NR Group). One week after surgery, 7 patients in the R Group (38.9%) and 11 patients in the NR Group (44.0%) had language function deterioration, and no significant difference was found (p=0.983). At long-term follow-up, 3 patients in the R Group (16.7%) and 4 patients in the NR Group (16.0%) still had aphasia, and no significant difference was observed (p=1.000). Although right-sided lateralization on fMRI might suggest language cortex reorganization, it is not a factor predicting better postoperative language outcome for AVM patients.

Extravasation of contrast (Spot Sign) predicts in-hospital mortality in ruptured arteriovenous malformation.

PubMed

Ye, Zengpanpan; Ai, Xiaolin; Zheng, Jun; Hu, Xin; You, Chao; Andrew M, Faramand; Fang, Fang

2017-10-09

The spot sign is a highly specific and sensitive predictor of hematoma expansion in following primary intracerebral hemorrhage (ICH). Rare cases of the spot sign have been documented in patients with intracranial hemorrhage secondary to arteriovenous malformation (AVM). The purpose of this retrospective study is to assess the accuracy of spot sign in predicting clinical outcomes in patients with ruptured AVM. A retrospective analysis of a prospectively maintained database was performed for patients who presented to West China Hospital with ICH secondary to AVM in the period between January 2009 and September 2016. Two radiologists blinded to the clinical data independently assessed the imaging data, including the presence of spot sign. Statistical analysis using univariate testing, multivariate logistic regression testing, and receiver operating characteristic curve (AUC) analysis was performed. A total of 116 patients were included. Overall, 18.9% (22/116) of subjects had at least 1 spot sign detected by CT angiography, 7% (8/116) died in hospital, and 27% (31/116) of the patients had a poor outcome after 90 days. The spot sign had a sensitivity of 62.5% and specificity of 84.3% for predicting in-hospital mortality (p = .02, AUC 0.734). No correlation detected between the spot sign and 90-day outcomes under multiple logistic regression (p = .19). The spot sign is an independent predictor for in-hospital mortality. The presence of spot sign did not correlate with the 90 day outcomes in this patient cohort. The results of this report suggest that patients with ruptured AVM with demonstrated the spot sign on imaging must receive aggressive treatment early on due to the high risk of mortality.

Detachable-Tip Microcatheters for Liquid Embolization of Brain Arteriovenous Malformations and Fistulas: A United States Single-Center Experience.

PubMed

Herial, Nabeel A; Khan, Asif A; Sherr, Gregory T; Qureshi, Mushtaq H; Suri, M Fareed K; Qureshi, Adnan I

2015-09-01

The US Food and Drug Administration recently approved a detachable-tip microcatheter, the Apollo microcatheter (eV3, Inc, Irvine, California), to prevent catheter entrapment during embolization of brain arteriovenous malformations (AVMs) using liquid embolic systems. To report technical aspects and clinical results of cerebral embolizations with the Apollo microcatheter in 7 embolizations in 3 adult patients. A 62-year-old man presented with an AVM in the parieto-occipital region measuring 3.6 × 1.6 cm with major cortical feeders from the right middle cerebral artery (MCA) and minor contribution from the distal right anterior cerebral artery. Two pedicles originating from the MCA were embolized. A 48-year-old woman presented with a left frontal AVM measuring 3.3 × 1.8 cm with arterial feeders from the left MCA, left middle meningeal artery, and contralateral anterior cerebral artery. Three pedicles originating from the left MCA were embolized. A 76-year-old man presented with an arteriovenous fistula with multiple fistulous connections and feeders from both vertebral and occipital arteries and the left posterior cerebral artery draining into the left transverse, torcula, and left sigmoid sinus. Two major occipital artery feeders were embolized. Seven Apollo microcatheters were used with the Onyx 18 liquid embolic system. The length of the detachable tip was 15 mm in 2 and 30 mm in 5 embolizations. The mean microcatheter in-position time within the pedicle was 20 minutes. Detachment of tip occurred in 3 instances. No limitations in accessing target arterial feeders and safe tip disengagement were noted despite prolonged injection times. Our initial experience supports the feasibility, safety, and effectiveness of detachable-tip microcatheters in treating brain AVMs and arteriovenous fistulas.

Treatment of Early-stage Extracranial Arteriovenous Malformations with Intralesional Interstitial Bleomycin Injection: A Pilot Study.

PubMed

Jin, Yunbo; Zou, Yun; Hua, Chen; Chen, Hui; Yang, Xi; Ma, Gang; Chang, Lei; Qiu, Yajing; Lyu, Dongze; Wang, Tianyou; Chang, Shih-Jen; Qiao, Congzhen; Luo, Chunfen; Tremp, Mathias; Lin, Xiaoxi

2018-04-01

Purpose To assess the efficacy and safety of intralesional interstitial bleomycin injection in the treatment of early-stage (Schobinger stage I or II) extracranial arteriovenous malformations (AVMs). Materials and Methods This prospective study involved 34 patients with early-stage AVMs, as defined by the Schobinger staging system. The patients received intralesional interstitial bleomycin injected at a maximum dose of 15 000 IU or 1000 IU per kilogram of body weight for children who weighed less than 15 kg per procedure for a total of 6 months (once every month). Therapeutic outcome was evaluated by the degree of devascularization at angiography and the clinical outcome 3 months after the last treatment. Further follow-up was evaluated based on further clinical outcome. Adverse events were recorded according to the Society of Interventional Radiology classification. Results Of the 34 patients with early-stage AVM, 32 (mean age, 20.5 years; 24 female [75%]) completed the study. The results showed that 27 (84.4%, 95% confidence interval [CI]: 71.1, 97.7) patients were responsive to bleomycin injection, including nine (28.1%) with a complete response. Four (12.5%) patients showed no response, and one (3.1%) patient experienced worsening 3 months after the last treatment. During further follow-up (mean follow-up time, 20.7 months; range, 5-28 months), the outcome remained stable in 31 (96.9%) of the 32 patients. A major complication, anaphylactic shock, was observed in one (3.1%, 95% CI: 0, 9.5) patient. Common minor complications included hyperpigmentation, nausea, pruritus, and bullae. Conclusion Intralesional interstitial bleomycin injection is a feasible approach for early-stage AVMs and yields safe and effective outcomes. © RSNA, 2017.

Uterine Vascular Lesions

PubMed Central

Vijayakumar, Abhishek; Srinivas, Amruthashree; Chandrashekar, Babitha Moogali; Vijayakumar, Avinash

2013-01-01

Vascular lesions of the uterus are rare; most reported in the literature are arteriovenous malformations (AVMs). Uterine AVMs can be congenital or acquired. In recent years, there has been an increasing number of reports of acquired vascular lesions of the uterus following pregnancy, abortion, cesarean delivery, and curettage. It can be seen from these reports that there is confusion concerning the terminology of uterine vascular lesions. There is also a lack of diagnostic criteria and management guidelines, which has led to an increased number of unnecessary invasive procedures (eg, angiography, uterine artery embolization, hysterectomy for abnormal vaginal bleeding). This article familiarizes readers with various vascular lesions of the uterus and their management. PMID:24340126

Pancreatic Arteriovenous Malformation Involving the Duodenum Embolized with Ethylene-Vinyl Alcohol Copolymer (Onyx)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grasso, Rosario Francesco, E-mail: r.grasso@unicampus.it; Cazzato, Roberto Luigi; Luppi, Giacomo

Arteriovenous malformation (AVM) of the pancreas is a rare condition. Most patients are asymptomatic or alternatively may present with a wide spectrum of symptoms. Traditionally, surgery has been considered the treatment of choice; however, alternative approaches, such as transcatheter embolization (TAE), may be proposed. We report a case of a 48-year-old man with a pancreatic head AVM, presenting with upper abdominal pain and slight anemia. The patient refused surgery and underwent TAE by means of ethylene-vinyl alcohol copolymer (EVOH). At 3 months follow-up, the patient was able to eat regularly, with no residual pain and no signs of anemia.

Radiosurgery for cerebral arteriovenous malformation during pregnancy: A case report focusing on fetal exposure to radiation

PubMed Central

Nagayama, Kazuki; Kurita, Hiroki; Tonari, Ayako; Takayama, Makoto; Shiokawa, Yoshiaki

2010-01-01

Introduction: We present the case of a pregnant woman who underwent linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) and we discuss the fetal exposure to radiation. Clinical Presentation: A 20-year-old woman at 18 weeks of gestation presented with right cerebral hemorrhage and underwent urgent evacuation of the hematoma. She recovered well after surgery, but cerebral angiography after the surgery revealed a small deeply seated arteriovenous malformation (AVM) in the right frontal lobe extending to the right basal ganglia. Methods and Results: We examined the diffuse AVM and treated it with LINAC-based SRS at 24 weeks of gestation. Before SRS, the fetus was exposed to a radiation dose of 8.26 mGy, which was estimated by conducting an experiment using an adult RANDO phantom, and a radiophotoluminescent (RPL) glass rod dosimeter (GRD) system. The patient underwent Caesarean delivery at 36 weeks of gestation and gave birth to a healthy baby. Conclusion: The exposure of fetus to radiation during SRS was exceedingly low. SRS can be used as an alternative treatment to microsurgery for resolving small deeply seated AVMs even in pregnant patients. PMID:22028762

Effectiveness of Preradiosurgical Embolization with NBCA for Arteriovenous Malformations - Retrospective Outcome Analysis in a Japanese Registry of 73 Patients (J-REAL study)

PubMed Central

Izumi, Takashi; Satow, Tetsu; Srivatanakul, Kittipong; Matsumoto, Yasushi; Terada, Tomoaki; Matsumaru, Yuji; Kiyosue, Hiro

2017-01-01

Purpose Recent reports have posed doubts about the effect of preradiosurgical embolization in brain arteriovenous malformation (AVM) because it makes the planning of stereotactic radiosurgery (SRS) difficult and has the risk of recanalization out of the target. We investigated whether the performance and quality of embolization may influence the success of SRS based on a retrospective case cohort study. Materials and Methods Seventy-three patients who underwent embolization followed by SRS between 2003 and 2012 in eight institutes with neurointerventionists were considered. They were divided into the following two groups at 3 years of follow up after the final SRS: “successful occlusion group” (S group), with radiologically complete occlusion of AVM; and “non-successful occlusion group” (N group) with persistent remnant nidus or abnormal vascular networks. Patient background, AVM profile, embolization performance grade and complications were compared in each group. The quality of embolization was evaluated with the new grading system: embolization performance grade (E grade), specializing the achievement of nidus embolization. E grade A was defined as sufficient nidus embolization with more than half of the total number of feeders achieving nidus penetration. E grade B was defined as less than half achievement of nidus embolization, and E grade C was defines as failure to perform nidus embolization. Results Forty-three patients were included in the S group, and 29 patients were included in the N group. The size and Spetzler-Martin grade of AVM and the rate of diffuse type was higher in the N group without statistical significance. The embolization performance level according to E grade indicated a significantly higher rate of successful embolization with more than 50% of nidus penetration in the S group (P<0.001). This difference was also confirmed in the subanalysis for limited cases, excluding smaller AVMs with complete occlusion with SRS alone (P=0.001). Conclusion The cause of the unsuccessful result of post-embolization SRS might be the large, diffuse angioarchitecture, but proper embolization with a high rate of nidus penetration to avoid recanalization is more important. Effective embolization is essential to contribute to and promote the effect of radiosurgery. PMID:28955512

GeoCrystal: graphic-interactive access to geodata archives

NASA Astrophysics Data System (ADS)

Goebel, Stefan; Haist, Joerg; Jasnoch, Uwe

2002-03-01

Recently there is spent a lot of effort to establish information systems and global infrastructures enabling both data suppliers and users to describe (-> eCommerce, metadata) as well as to find appropriate data. Examples for this are metadata information systems, online-shops or portals for geodata. The main disadvantages of existing approaches are insufficient methods and mechanisms leading users to (e.g. spatial) data archives. This affects aspects concerning usability and personalization in general as well as visual feedback techniques in the different steps of the information retrieval process. Several approaches aim at the improvement of graphical user interfaces by using intuitive metaphors, but only some of them offer 3D interfaces in the form of information landscapes or geographic result scenes in the context of information systems for geodata. This paper presents GeoCrystal, which basic idea is to adopt Venn diagrams to compose complex queries and to visualize search results in a 3D information and navigation space for geodata. These concepts are enhanced with spatial metaphors and 3D information landscapes (library for geodata) wherein users can specify searches for appropriate geodata and are enabled to graphic-interactively communicate with search results (book metaphor).

Earthdata Search: How Usability Drives Innovation To Enable A Broad User Base

NASA Astrophysics Data System (ADS)

Reese, M.; Siarto, J.; Lynnes, C.; Shum, D.

2017-12-01

Earthdata Search (https://search.earthdata.nasa.gov) is a modern web application allowing users to search, discover, visualize, refine, and access NASA Earth Observation data using a wide array of service offerings. Its goal is to ease the technical burden on data users by providing a high-quality application that makes it simple to interact with NASA Earth observation data, freeing them to spend more effort on innovative endeavors. This talk would detail how we put end users first in our design and development process, focusing on usability and letting usability needs drive requirements for the underlying technology. Just a few examples of how this plays out practically, Earthdata Search teams with a lightning fast metadata repository, allowing it to be an extremely responsive UI that updates as the user changes criteria not only at the dataset level, but also at the file level. This results in a better exploration experience as the time penalty is greatly reduced. Also, since Earthdata Search uses metadata from over 35,000 datasets that are managed by different data providers, metadata standards, quality and consistency will vary. We found that this was negatively impacting users' search and exploration experience. We have resolved this problem with the introduction of "humanizers", which is a community-driven process to both "smooth out" metadata values and provide non-jargonistic representations of some content within the Earthdata Search UI. This is helpful for both the experience data scientist and our users that are brand new to the discipline.

Evolution of Web Services in EOSDIS: Search and Order Metadata Registry (ECHO)

NASA Technical Reports Server (NTRS)

Mitchell, Andrew; Ramapriyan, Hampapuram; Lowe, Dawn

2009-01-01

During 2005 through 2008, NASA defined and implemented a major evolutionary change in it Earth Observing system Data and Information System (EOSDIS) to modernize its capabilities. This implementation was based on a vision for 2015 developed during 2005. The EOSDIS 2015 Vision emphasizes increased end-to-end data system efficiency and operability; increased data usability; improved support for end users; and decreased operations costs. One key feature of the Evolution plan was achieving higher operational maturity (ingest, reconciliation, search and order, performance, error handling) for the NASA s Earth Observing System Clearinghouse (ECHO). The ECHO system is an operational metadata registry through which the scientific community can easily discover and exchange NASA's Earth science data and services. ECHO contains metadata for 2,726 data collections comprising over 87 million individual data granules and 34 million browse images, consisting of NASA s EOSDIS Data Centers and the United States Geological Survey's Landsat Project holdings. ECHO is a middleware component based on a Service Oriented Architecture (SOA). The system is comprised of a set of infrastructure services that enable the fundamental SOA functions: publish, discover, and access Earth science resources. It also provides additional services such as user management, data access control, and order management. The ECHO system has a data registry and a services registry. The data registry enables organizations to publish EOS and other Earth-science related data holdings to a common metadata model. These holdings are described through metadata in terms of datasets (types of data) and granules (specific data items of those types). ECHO also supports browse images, which provide a visual representation of the data. The published metadata can be mapped to and from existing standards (e.g., FGDC, ISO 19115). With ECHO, users can find the metadata stored in the data registry and then access the data either directly online or through a brokered order to the data archive organization. ECHO stores metadata from a variety of science disciplines and domains, including Climate Variability and Change, Carbon Cycle and Ecosystems, Earth Surface and Interior, Atmospheric Composition, Weather, and Water and Energy Cycle. ECHO also has a services registry for community-developed search services and data services. ECHO provides a platform for the publication, discovery, understanding and access to NASA s Earth Observation resources (data, service and clients). In their native state, these data, service and client resources are not necessarily targeted for use beyond their original mission. However, with the proper interoperability mechanisms, users of these resources can expand their value, by accessing, combining and applying them in unforeseen ways.

CHARMe Commentary metadata for Climate Science: collecting, linking and sharing user feedback on climate datasets

NASA Astrophysics Data System (ADS)

Blower, Jon; Lawrence, Bryan; Kershaw, Philip; Nagni, Maurizio

2014-05-01

The research process can be thought of as an iterative activity, initiated based on prior domain knowledge, as well on a number of external inputs, and producing a range of outputs including datasets, studies and peer reviewed publications. These outputs may describe the problem under study, the methodology used, the results obtained, etc. In any new publication, the author may cite or comment other papers or datasets in order to support their research hypothesis. However, as their work progresses, the researcher may draw from many other latent channels of information. These could include for example, a private conversation following a lecture or during a social dinner; an opinion expressed concerning some significant event such as an earthquake or for example a satellite failure. In addition, other sources of information of grey literature are important public such as informal papers such as the arxiv deposit, reports and studies. The climate science community is not an exception to this pattern; the CHARMe project, funded under the European FP7 framework, is developing an online system for collecting and sharing user feedback on climate datasets. This is to help users judge how suitable such climate data are for an intended application. The user feedback could be comments about assessments, citations, or provenance of the dataset, or other information such as descriptions of uncertainty or data quality. We define this as a distinct category of metadata called Commentary or C-metadata. We link C-metadata with target climate datasets using a Linked Data approach via the Open Annotation data model. In the context of Linked Data, C-metadata plays the role of a resource which, depending on its nature, may be accessed as simple text or as more structured content. The project is implementing a range of software tools to create, search or visualize C-metadata including a JavaScript plugin enabling this functionality to be integrated in situ with data provider portals. Since commentary metadata may originate from a range of sources, moderation of this information will become a crucial issue. If the project is successful, expert human moderation (analogous to peer-review) will become impracticable as annotation numbers increase, and some combination of algorithmic and crowd-sourced evaluation of commentary metadata will be necessary. To that end, future work will need to extend work under development to enable access control and checking of inputs, to deal with scale.

The Virtual Cosmos Project: Astronomical Data access for General Public via the National Virtual Observatory

NASA Astrophysics Data System (ADS)

Craig, N.; Mendez, B. J.; Hanisch, R. J.; Christian, C. A.; Summers, F.; Haisch, B.; Lindblom, J.

2005-05-01

We will describe the development of protocols to make Astronomy press-release quality images from HST and other sources publicly available through compatibility with the National Virtual Observatory (NVO). We will present the designs for a public portal to these resources, based on a robust evaluation of our intended audience. The availability of press-release quality materials via the NVO through a simplified interface will greatly enhance the utility of these materials for the public. Behind any portal to NVO data there is a standard registry and data structures that allow collections of data (such as the press release images) to be located and acquired. We will describe our design of the necessary protocols and metadata being used within the NVO framework for this project. We base our meta-tags on the considerable existing work done in the science community as well as the NASA education community. These refined metadata are applied to new HST press-release images as they are produced and registered with the NVO. We will describe methods for retrofitting pre-existing imagery with the metadata standards. The rich media, 3D navigation and visualization capabilities of the browser created by ManyOne Network Inc. are particularly well suited to the presentation of astronomical information and ever more detailed models of the local neighborhood, the Milky Way, etc. We will discuss the 3D navigation and visualization capabilities of the browser with particular focus on the Milky Way Galaxy. Development of an online encyclopedia to accompany the ManyOne portals as part of the Virtual Cosmos will also be described. Support from NASA's AISR Program is gratefully acknowledged.

Use of the Apollo detachable-tip microcatheter for endovascular embolization of arteriovenous malformations and arteriovenous fistulas.

PubMed

Flores, Bruno C; See, Alfred P; Weiner, Gregory M; Jankowitz, Brian T; Ducruet, Andrew F; Albuquerque, Felipe C

2018-03-23

OBJECTIVE Liquid embolic agents have revolutionized endovascular management of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). Nonetheless, since 2005, the US FDA has received more than 100 reports of microcatheter breakage or entrapment related to Onyx embolization, including 9 deaths. In 2014, the Apollo detachable-tip microcatheter became the first of its kind available in the US. Since then, few reports on its safety have been published. METHODS The authors conducted a retrospective review of endovascular cases by searching the patient databases at 2 tertiary cerebrovascular centers (Barrow Neurological Institute and University of Pittsburgh Medical Center). Patients who underwent endovascular embolization of an AVM or AVF using the Apollo microcatheter were identified. Patient demographics and lesion characteristics were collected. The authors analyzed Apollo-specific endovascular variables, such as number of microcatheterizations, sessions, and pedicles embolized; microcatheter tip detachment status; obliteration rate; and endovascular- and microcatheter-related morbidity and mortality. RESULTS From July 2014 to October 2016, a total of 177 embolizations using the Apollo microcatheter were performed in 61 patients (mean age 40.3 years). The most frequent presentation was hemorrhage (22/61, 36.1%). Most lesions were AVMs (51/61, 83.6%; mean diameter 30.6 mm). The mean Spetzler-Martin grade was 2.4. Thirty-nine (76.5%) of 51 patients with AVMs underwent resection. Microcatheterization was successful in 172 pedicles. Most patients (50/61, 82%) underwent a single embolization session. The mean number of pedicles per session was 2.5 (range 1-7). Onyx-18 was used in 103 (59.9%), N-butyl cyanoacrylate (NBCA) in 44 (25.6%), and Onyx-34 in 25 (14.5%) of the 172 embolizations. In 45.9% (28/61) of the patients, lesion obliteration of 75% or greater was achieved. Tip detachment occurred in 19.2% (33/172) of microcatheters. Fifty-three (86.9%) of the 61 patients who underwent embolization with the Apollo microcatheter had good functional outcomes (modified Rankin Scale score 0-2). No unintended microcatheter fractures or related morbidity was observed. One patient died of intraprocedural complications unrelated to microcatheter selection. In the univariate analysis, microcatheter tip detachment (p = 0.12), single embolized pedicles (p = 0.12), and smaller AVM nidus diameter (p = 0.17) correlated positively with high obliteration rates (> 90%). In the multivariate analysis, microcatheter tip detachment was the only independent variable associated with high obliteration rates (OR 9.5; p = 0.03). CONCLUSIONS The use of the Apollo detachable-tip microcatheter for embolization of AVMs and AVFs is associated with high rates of successful catheterization and obliteration and low rates of morbidity and mortality. The microcatheter was retrieved in all cases, even after prolonged injections in distal branch pedicles, often with significant reflux. This study represents the largest case series on the application of the Apollo microcatheter for neurointerventional procedures.

Echo™ User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, Dustin Yewell

Echo™ is a MATLAB-based software package designed for robust and scalable analysis of complex data workflows. An alternative to tedious, error-prone conventional processes, Echo is based on three transformative principles for data analysis: self-describing data, name-based indexing, and dynamic resource allocation. The software takes an object-oriented approach to data analysis, intimately connecting measurement data with associated metadata. Echo operations in an analysis workflow automatically track and merge metadata and computation parameters to provide a complete history of the process used to generate final results, while automated figure and report generation tools eliminate the potential to mislabel those results. History reportingmore » and visualization methods provide straightforward auditability of analysis processes. Furthermore, name-based indexing on metadata greatly improves code readability for analyst collaboration and reduces opportunities for errors to occur. Echo efficiently manages large data sets using a framework that seamlessly allocates resources such that only the necessary computations to produce a given result are executed. Echo provides a versatile and extensible framework, allowing advanced users to add their own tools and data classes tailored to their own specific needs. Applying these transformative principles and powerful features, Echo greatly improves analyst efficiency and quality of results in many application areas.« less

Dynamic publication model for neurophysiology databases.

PubMed

Gardner, D; Abato, M; Knuth, K H; DeBellis, R; Erde, S M

2001-08-29

We have implemented a pair of database projects, one serving cortical electrophysiology and the other invertebrate neurones and recordings. The design for each combines aspects of two proven schemes for information interchange. The journal article metaphor determined the type, scope, organization and quantity of data to comprise each submission. Sequence databases encouraged intuitive tools for data viewing, capture, and direct submission by authors. Neurophysiology required transcending these models with new datatypes. Time-series, histogram and bivariate datatypes, including illustration-like wrappers, were selected by their utility to the community of investigators. As interpretation of neurophysiological recordings depends on context supplied by metadata attributes, searches are via visual interfaces to sets of controlled-vocabulary metadata trees. Neurones, for example, can be specified by metadata describing functional and anatomical characteristics. Permanence is advanced by data model and data formats largely independent of contemporary technology or implementation, including Java and the XML standard. All user tools, including dynamic data viewers that serve as a virtual oscilloscope, are Java-based, free, multiplatform, and distributed by our application servers to any contemporary networked computer. Copyright is retained by submitters; viewer displays are dynamic and do not violate copyright of related journal figures. Panels of neurophysiologists view and test schemas and tools, enhancing community support.

Exploring Cultural Heritage Resources in a 3d Collaborative Environment

NASA Astrophysics Data System (ADS)

Respaldiza, A.; Wachowicz, M.; Vázquez Hoehne, A.

2012-06-01

Cultural heritage is a complex and diverse concept, which brings together a wide domain of information. Resources linked to a cultural heritage site may consist of physical artefacts, books, works of art, pictures, historical maps, aerial photographs, archaeological surveys and 3D models. Moreover, all these resources are listed and described by a set of a variety of metadata specifications that allow their online search and consultation on the most basic characteristics of them. Some examples include Norma ISO 19115, Dublin Core, AAT, CDWA, CCO, DACS, MARC, MoReq, MODS, MuseumDat, TGN, SPECTRUM, VRA Core and Z39.50. Gateways are in place to fit in these metadata standards into those used in a SDI (ISO 19115 or INSPIRE), but substantial work still remains to be done for the complete incorporation of cultural heritage information. Therefore, the aim of this paper is to demonstrate how the complexity of cultural heritage resources can be dealt with by a visual exploration of their metadata within a 3D collaborative environment. The 3D collaborative environments are promising tools that represent the new frontier of our capacity of learning, understanding, communicating and transmitting culture.

HTML5 PivotViewer: high-throughput visualization and querying of image data on the web.

PubMed

Taylor, Stephen; Noble, Roger

2014-09-15

Visualization and analysis of large numbers of biological images has generated a bottle neck in research. We present HTML5 PivotViewer, a novel, open source, platform-independent viewer making use of the latest web technologies that allows seamless access to images and associated metadata for each image. This provides a powerful method to allow end users to mine their data. Documentation, examples and links to the software are available from http://www.cbrg.ox.ac.uk/data/pivotviewer/. The software is licensed under GPLv2. © The Author 2014. Published by Oxford University Press.

Mechanical Removal of Migrated Onyx Due to Microcatheter Rupture During AVM Embolization: A Technical Case Report.

PubMed

Senturk, Cagin

2015-12-01

We report a case where migrated Onyx could be removed safely with a mechanical thrombectomy device after withdrawal of the damaged microcatheter. A microcatheter was retained in the superior cerebellar artery with attached Onyx fragments on its tip during embolization of a bled cerebellar AVM. During retrieval maneuvers microcatheter shaft was ruptured and Onyx fragments were released into the vertebrobasilar system causing occlusion. Finally, Onyx fragment on tip of the microcatheter could be detached with dimethyl sulfoxide injection and the microcatheter could be withdrawn. A Merci retriever device (Concentric Medical, Mountain View, CA, USA) was successfully used to retrieve most of the dislodged Onyx material and recanalize the vertebrobasilar circulation.

An endovascular option is the final treatment for a giant arteriovenous malformation.

PubMed

Benedetto, Filippo; Pipitò, Narayana; Barillà, David; Spinelli, Domenico; Stilo, Francesco; Spinelli, Francesco

2014-11-01

We report the case of a 58-year-old man presented with bleeding ulcer of the left arm caused by a high-flow type-C arteriovenous malformation (AVM), feed by branches from both the subclavian arteries. He had been previously treated with AVM sclerotherapy, embolization, humeral artery endografting, and open surgery. We urgently performed coil embolization of the left vertebral artery, and we covered the huge subclavian artery by a thoracic endograft. Then, we embolized the right tyrocervical trunk. The result was an immediate interruption of bleeding. At 12 months, the patient had no neurologic complications, and the upper limb continued to decompress. Copyright © 2014 Elsevier Inc. All rights reserved.

The acoustic streamflow-measuring system on the Columbia River at The Dalles, Oregon

USGS Publications Warehouse

Smith, Winchell; Hubbard, Larry L.; Laenen, Antonius

1971-01-01

Installation of this sytem, which is the first application of an AVM (acoustic velocity meter) in a large natural channel, was completed in April 1969. It has been in continuous operation since that date. Performance has been satisfactory, and similar installations at other key points in the Columbia River basin are now under consideration. This paper covers the general theory behind acoustic velocity meters, tracing development from earlier concepts to the present commercially available system. Conclusions are that the AVM can now be considered as an operational instrument which permits accurate gaging of river discharge at many sites where conventional stream-gaging procedures have proved to be unreliable.

Does Working Memory Impact Functional Outcomes in Individuals With ADHD: A Qualitative and Comprehensive Literature Review.

PubMed

Fried, Ronna; Abrams, Jessica; Hall, Anna; Feinberg, Leah; Pope, Amanda; Biederman, Joseph

2017-09-01

Working Memory (WM) is a domain of executive functioning often impaired in individuals with ADHD. Although assumed to cause difficulties across functioning, the scope of impairments from WM deficits in ADHD has not been investigated. The aim of this study was to examine outcomes associated with WM deficits in ADHD. We conducted a search of the scientific literature on WM deficits, and Freedom From Distractibility (FFD), in ADHD using PubMed and PsycInfo databases. The final sample included 11 controlled studies of WM/FFD deficits in ADHD with operationalized assessment of outcomes in academic, social, and emotional areas. WM assessment was divided into auditory-verbal memory (AVM) and spatial-visual memory (SWM). Seven studies examined WM deficits in academic functioning, eight studies assessed WM deficits in social functioning, and three assessed WM deficits in psychopathology. The majority of the literature suggests that WM deficits affect primarily academic functioning.

Current Trends in Intraoperative Optical Imaging for Functional Brain Mapping and Delineation of Lesions of Language Cortex

PubMed Central

Prakash, Neal; Uhleman, Falk; Sheth, Sameer A.; Bookheimer, Susan; Martin, Neil; Toga, Arthur W.

2009-01-01

Resection of a cerebral arteriovenous malformation (AVM), epileptic focus, or glioma, ideally has a prerequisite of microscopic delineation of the lesion borders in relation to the normal gray and white matter that mediate critical functions. Currently, Wada testing and functional magnetic resonance imaging (fMRI) are used for preoperative mapping of critical function, whereas electrical stimulation mapping (ESM) is used for intraoperative mapping. For lesion delineation, MRI and positron emission tomography (PET) are used preoperatively, whereas microscopy and histological sectioning are used intraoperatively. However, for lesions near eloquent cortex, these imaging techniques may lack sufficient resolution to define the relationship between the lesion and language function, and thus not accurately determine which patients will benefit from neurosurgical resection of the lesion without iatrogenic aphasia. Optical techniques such as intraoperative optical imaging of intrinsic signals (iOIS) show great promise for the precise functional mapping of cortices, as well as delineation of the borders of AVMs, epileptic foci, and gliomas. Here we first review the physiology of neuroimaging, and then progress towards the validation and justification of using intraoperative optical techniques, especially in relation to neurosurgical planning of resection AVMs, epileptic foci, and gliomas near or in eloquent cortex. We conclude with a short description of potential novel intraoperative optical techniques. PMID:18786643

MR angiography fusion technique for treatment planning of intracranial arteriovenous malformations.

PubMed

McGee, Kiaran P; Ivanovic, Vladimir; Felmlee, Joel P; Meyer, Fredrick B; Pollock, Bruce E; Huston, John

2006-03-01

To develop an image fusion technique using elliptical centric contrast-enhanced (CE) MR angiography (MRA) and three-dimensional (3D) time-of-flight (TOF) acquisitions for radiosurgery treatment planning of arteriovenous malformations (AVMs). CE and 3D-TOF MR angiograms with disparate in-plane fields of view (FOVs) were acquired, followed by k-space reformatting to provide equal voxel dimensions. Spatial domain addition was performed to provide a third, fused data volume. Spatial distortion was evaluated on an MRA phantom and provided slice-dependent and global distortion along the three physical dimensions of the MR scanner. In vivo validation was performed on 10 patients with intracranial AVMs prior to their conventional angiogram on the day of gamma knife radiosurgery. Spatial distortion in the phantom within a volume of 14 x 14 x 3.2 cm(3) was less than +/-1 mm (+/-1 standard deviation (SD)) for CE and 3D-TOF data sets. Fused data volumes were successfully generated for all 10 patients. Image fusion can be used to obtain high-resolution CE-MRA images of intracranial AVMs while keeping the fiducial markers needed for gamma knife radiosurgery planning. The spatial fidelity of these data is within the tolerance acceptable for daily quality control (QC) purposes and gamma knife treatment planning. (c) 2006 Wiley-Liss, Inc.

Defects of Vps15 in skeletal muscles lead to autophagic vacuolar myopathy and lysosomal disease

PubMed Central

Nemazanyy, Ivan; Blaauw, Bert; Paolini, Cecilia; Caillaud, Catherine; Protasi, Feliciano; Mueller, Amelie; Proikas-Cezanne, Tassula; Russell, Ryan C; Guan, Kun-Liang; Nishino, Ichizo; Sandri, Marco; Pende, Mario; Panasyuk, Ganna

2013-01-01

The complex of Vacuolar Protein Sorting 34 and 15 (Vps34 and Vps15) has Class III phosphatidylinositol 3-kinase activity and putative roles in nutrient sensing, mammalian Target Of Rapamycin (mTOR) activation by amino acids, cell growth, vesicular trafficking and autophagy. Contrary to expectations, here we show that Vps15-deficient mouse tissues are competent for LC3-positive autophagosome formation and maintain mTOR activation. However, an impaired lysosomal function in mutant cells is traced by accumulation of adaptor protein p62, LC3 and Lamp2 positive vesicles, which can be reverted to normal levels after ectopic overexpression of Vps15. Mice lacking Vps15 in skeletal muscles, develop a severe myopathy. Distinct from the autophagy deficient Atg7−/− mutants, pathognomonic morphological hallmarks of autophagic vacuolar myopathy (AVM) are observed in Vps15−/− mutants, including elevated creatine kinase plasma levels, accumulation of autophagosomes, glycogen and sarcolemmal features within the fibres. Importantly, Vps34/Vps15 overexpression in myoblasts of Danon AVM disease patients alleviates the glycogen accumulation. Thus, the activity of the Vps34/Vps15 complex is critical in disease conditions such as AVMs, and possibly a variety of other lysosomal storage diseases. PMID:23630012

Distributed metadata servers for cluster file systems using shared low latency persistent key-value metadata store

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bent, John M.; Faibish, Sorin; Pedone, Jr., James M.

A cluster file system is provided having a plurality of distributed metadata servers with shared access to one or more shared low latency persistent key-value metadata stores. A metadata server comprises an abstract storage interface comprising a software interface module that communicates with at least one shared persistent key-value metadata store providing a key-value interface for persistent storage of key-value metadata. The software interface module provides the key-value metadata to the at least one shared persistent key-value metadata store in a key-value format. The shared persistent key-value metadata store is accessed by a plurality of metadata servers. A metadata requestmore » can be processed by a given metadata server independently of other metadata servers in the cluster file system. A distributed metadata storage environment is also disclosed that comprises a plurality of metadata servers having an abstract storage interface to at least one shared persistent key-value metadata store.« less

The Arctic Cooperative Data and Information System: Data Management Support for the NSF Arctic Research Program (Invited)

NASA Astrophysics Data System (ADS)

Moore, J.; Serreze, M. C.; Middleton, D.; Ramamurthy, M. K.; Yarmey, L.

2013-12-01

The NSF funds the Advanced Cooperative Arctic Data and Information System (ACADIS), url: (http://www.aoncadis.org/). It serves the growing and increasingly diverse data management needs of NSF's arctic research community. The ACADIS investigator team combines experienced data managers, curators and software engineers from the NSIDC, UCAR and NCAR. ACADIS fosters scientific synthesis and discovery by providing a secure long-term data archive to NSF investigators. The system provides discovery and access to arctic related data from this and other archives. This paper updates the technical components of ACADIS, the implementation of best practices, the value of ACADIS to the community and the major challenges facing this archive for the future in handling the diverse data coming from NSF Arctic investigators. ACADIS provides sustainable data management, data stewardship services and leadership for the NSF Arctic research community through open data sharing, adherence to best practices and standards, capitalizing on appropriate evolving technologies, community support and engagement. ACADIS leverages other pertinent projects, capitalizing on appropriate emerging technologies and participating in emerging cyberinfrastructure initiatives. The key elements of ACADIS user services to the NSF Arctic community include: data and metadata upload; support for datasets with special requirements; metadata and documentation generation; interoperability and initiatives with other archives; and science support to investigators and the community. Providing a self-service data publishing platform requiring minimal curation oversight while maintaining rich metadata for discovery, access and preservation is challenging. Implementing metadata standards are a first step towards consistent content. The ACADIS Gateway and ADE offer users choices for data discovery and access with the clear objective of increasing discovery and use of all Arctic data especially for analysis activities. Metadata is at the core of ACADIS activities, from capturing metadata at the point of data submission to ensuring interoperability , providing data citations, and supporting data discovery. ACADIS metadata efforts include: 1) Evolution of the ACADIS metadata profile to increase flexibility in search; 2) Documentation guidelines; and 3) Metadata standardization efforts. A major activity is now underway to ensure consistency in the metadata profile across all archived datasets. ACADIS is embarking on a critical activity to create Digital Object Identifiers (DOI) for all its holdings. The data services offered by ACADIS focus on meeting the needs of the data providers, providing dynamic search capabilities to peruse the ACADIS and related cyrospheric data repositories, efficient data download and some special services including dataset reformatting and visualization. The service is built around of the following key technical elements: The ACADIS Gateway housed at NCAR has been developed to support NSF Arctic data coming from AON and now broadly across PLR/ARC and related archives: The Arctic Data Explorer (ADE) developed at NSIDC is an integral service of ACADIS bringing the rich archive from NSIDC together with catalogs from ACADIS and international partners in Arctic research: and Rosetta and the Digital Object Identifier (DOI) generation scheme are tools available to the community to help publish and utilize datasets in integration and synthesis and publication.

Finding Atmospheric Composition (AC) Metadata

NASA Technical Reports Server (NTRS)

Strub, Richard F..; Falke, Stefan; Fiakowski, Ed; Kempler, Steve; Lynnes, Chris; Goussev, Oleg

2015-01-01

The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not all) Earth science atmospheric composition data providers store a reference to their data at GCMD.

Automated Atmospheric Composition Dataset Level Metadata Discovery. Difficulties and Surprises

NASA Astrophysics Data System (ADS)

Strub, R. F.; Falke, S. R.; Kempler, S.; Fialkowski, E.; Goussev, O.; Lynnes, C.

2015-12-01

The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System - CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not all) Earth science atmospheric composition data providers store a reference to their data at GCMD.

Scientific Platform as a Service - Tools and solutions for efficient access to and analysis of oceanographic data

NASA Astrophysics Data System (ADS)

Vines, Aleksander; Hansen, Morten W.; Korosov, Anton

2017-04-01

Existing infrastructure international and Norwegian projects, e.g., NorDataNet, NMDC and NORMAP, provide open data access through the OPeNDAP protocol following the conventions for CF (Climate and Forecast) metadata, designed to promote the processing and sharing of files created with the NetCDF application programming interface (API). This approach is now also being implemented in the Norwegian Sentinel Data Hub (satellittdata.no) to provide satellite EO data to the user community. Simultaneously with providing simplified and unified data access, these projects also seek to use and establish common standards for use and discovery metadata. This then allows development of standardized tools for data search and (subset) streaming over the internet to perform actual scientific analysis. A combinnation of software tools, which we call a Scientific Platform as a Service (SPaaS), will take advantage of these opportunities to harmonize and streamline the search, retrieval and analysis of integrated satellite and auxiliary observations of the oceans in a seamless system. The SPaaS is a cloud solution for integration of analysis tools with scientific datasets via an API. The core part of the SPaaS is a distributed metadata catalog to store granular metadata describing the structure, location and content of available satellite, model, and in situ datasets. The analysis tools include software for visualization (also online), interactive in-depth analysis, and server-based processing chains. The API conveys search requests between system nodes (i.e., interactive and server tools) and provides easy access to the metadata catalog, data repositories, and the tools. The SPaaS components are integrated in virtual machines, of which provisioning and deployment are automatized using existing state-of-the-art open-source tools (e.g., Vagrant, Ansible, Docker). The open-source code for scientific tools and virtual machine configurations is under version control at https://github.com/nansencenter/, and is coupled to an online continuous integration system (e.g., Travis CI).

Report on the Global Data Assembly Center (GDAC) to the 12th GHRSST Science Team Meeting

NASA Technical Reports Server (NTRS)

Armstrong, Edward M.; Bingham, Andrew; Vazquez, Jorge; Thompson, Charles; Huang, Thomas; Finch, Chris

2011-01-01

In 2010/2011 the Global Data Assembly Center (GDAC) at NASA's Physical Oceanography Distributed Active Archive Center (PO.DAAC) continued its role as the primary clearinghouse and access node for operational Group for High Resolution Sea Surface Temperature (GHRSST) datastreams, as well as its collaborative role with the NOAA Long Term Stewardship and Reanalysis Facility (LTSRF) for archiving. Here we report on our data management activities and infrastructure improvements since the last science team meeting in June 2010.These include the implementation of all GHRSST datastreams in the new PO.DAAC Data Management and Archive System (DMAS) for more reliable and timely data access. GHRSST dataset metadata are now stored in a new database that has made the maintenance and quality improvement of metadata fields more straightforward. A content management system for a revised suite of PO.DAAC web pages allows dynamic access to a subset of these metadata fields for enhanced dataset description as well as discovery through a faceted search mechanism from the perspective of the user. From the discovery and metadata standpoint the GDAC has also implemented the NASA version of the OpenSearch protocol for searching for GHRSST granules and developed a web service to generate ISO 19115-2 compliant metadata records. Furthermore, the GDAC has continued to implement a new suite of tools and services for GHRSST datastreams including a Level 2 subsetter known as Dataminer, a revised POET Level 3/4 subsetter and visualization tool, a Google Earth interface to selected daily global Level 2 and Level 4 data, and experimented with a THREDDS catalog of GHRSST data collections. Finally we will summarize the expanding user and data statistics, and other metrics that we have collected over the last year demonstrating the broad user community and applications that the GHRSST project continues to serve via the GDAC distribution mechanisms. This report also serves by extension to summarize the activities of the GHRSST Data Assembly and Systems Technical Advisory Group (DAS-TAG).

Dose fractionated gamma knife radiosurgery for large arteriovenous malformations on daily or alternate day schedule outside the linear quadratic model: Proof of concept and early results. A substitute to volume fractionation.

PubMed

Mukherjee, Kanchan Kumar; Kumar, Narendra; Tripathi, Manjul; Oinam, Arun S; Ahuja, Chirag K; Dhandapani, Sivashanmugam; Kapoor, Rakesh; Ghoshal, Sushmita; Kaur, Rupinder; Bhatt, Sandeep

2017-01-01

To evaluate the feasibility, safety and efficacy of dose fractionated gamma knife radiosurgery (DFGKRS) on a daily schedule beyond the linear quadratic (LQ) model, for large volume arteriovenous malformations (AVMs). Between 2012-16, 14 patients of large AVMs (median volume 26.5 cc) unsuitable for surgery or embolization were treated in 2-3 of DFGKRS sessions. The Leksell G frame was kept in situ during the whole procedure. 86% (n = 12) patients had radiologic evidence of bleed, and 43% (n = 6) had presented with a history of seizures. 57% (n = 8) patients received a daily treatment for 3 days and 43% (n = 6) were on an alternate day (2 fractions) regimen. The marginal dose was split into 2 or 3 fractions of the ideal prescription dose of a single fraction of 23-25 Gy. The median follow up period was 35.6 months (8-57 months). In the three-fraction scheme, the marginal dose ranged from 8.9-11.5 Gy, while in the two-fraction scheme, the marginal dose ranged from 11.3-15 Gy at 50% per fraction. Headache (43%, n = 6) was the most common early postoperative complication, which was controlled with short course steroids. Follow up evaluation of at least three years was achieved in seven patients, who have shown complete nidus obliteration in 43% patients while the obliteration has been in the range of 50-99% in rest of the patients. Overall, there was a 67.8% reduction in the AVM volume at 3 years. Nidus obliteration at 3 years showed a significant rank order correlation with the cumulative prescription dose (p 0.95, P value 0.01), with attainment of near-total (more than 95%) obliteration rates beyond 29 Gy of the cumulative prescription dose. No patient receiving a cumulative prescription dose of less than 31 Gy had any severe adverse reaction. In co-variate adjusted ordinal regression, only the cumulative prescription dose had a significant correlation with common terminology criteria for adverse events (CTCAE) severity (P value 0.04), independent of age, AVM volume, number of fractions and volume of brain receiving atleast 8 Gy of radiation. DFGKRS is feasible for large AVMs with a fair nidus obliteration rate and acceptable toxicity. Cumulative prescription dose seems to be the most significant independent predictor for outcome following DFGKRS with 29-30 Gy resulting in a fair nidus obliteration with least adverse events.

Time resolved imaging of contrast kinetics (TRICKS) MR angiography of arteriovenous malformations of head and neck.

PubMed

Razek, Ahmed Abdel Khalek Abdel; Gaballa, Gada; Megahed, Abdel Salam; Elmogy, Ebrahiem

2013-11-01

To evaluate vasculature of arteriovenous malformations (AVMs) of head and neck with time resolved imaging of contrast kinetics (TRICKS) MR angiography (MRA). Prospective study was conducted upon 19 patients (age range, 12-29 years; mean age 18 years; 10 males and 9 females) with AVM of head and neck. TRICKS-MRA of head and neck was performed during injection of contrast medium. Post processing with reconstruction of the images was done. Two independent readers assessed the overall TRICKS-MRA image quality score using a 5-point scale and depiction of the main arterial feeders, nidus, and venous drainage using 3 points scale. The Kappa test for interobserver agreement was done. The AVMs were evaluated morphologically in terms of number and origin of the main arterial feeders, the location and size of nidus either small (>2 cm) or large (>2 cm) and the draining veins into the superficial or deep venous drainage. The average TRICKS-MRA image quality score as judged by reader 1 was 3.89 ± 1.15 and that as judged by reader 2 was 3.89 ± 0.10, which yielded excellent interobserver agreement (k=0.77, 95% CI=0.53-0.98, r=0.78, P=0.001). The interobserver agreement of both readers was excellent for the arterial feeders (k=0.81, 95% CI=0.57-1.00, r=0.83, P=0.001), excellent for the nidus (k=0.91, 95% CI=0.75-1.00, r=0.92, P=0.001), and good for the venous drainage (k=0.77, 95% CI=0.53-0.98, r=0.78, P=0.001). The arterial feeders were single (n=14) or multiple (n=5), the nidus was large (n=16) or small (n=3) and the venous drainage was into the internal jugular (n=17) or the external jugular (n=2) veins. Three patients with small nidus and single arterial feeder were treated with sclerotherapy. Eleven patients with large nidus and single arterial feeder were referred for embolization. Combined embolization and surgery were done for five patients with large nidus and multiple arterial feeders. We concluded that TRICKS-MRA is a reliable non invasive tool for evaluation of the feeding arteries, the nidus and the draining veins of AVMs of head and neck. TRICKS-MRA can be used for evaluation and treatment planning of AVMs of head and neck. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Karst database development in Minnesota: Design and data assembly

USGS Publications Warehouse

Gao, Y.; Alexander, E.C.; Tipping, R.G.

2005-01-01

The Karst Feature Database (KFD) of Minnesota is a relational GIS-based Database Management System (DBMS). Previous karst feature datasets used inconsistent attributes to describe karst features in different areas of Minnesota. Existing metadata were modified and standardized to represent a comprehensive metadata for all the karst features in Minnesota. Microsoft Access 2000 and ArcView 3.2 were used to develop this working database. Existing county and sub-county karst feature datasets have been assembled into the KFD, which is capable of visualizing and analyzing the entire data set. By November 17 2002, 11,682 karst features were stored in the KFD of Minnesota. Data tables are stored in a Microsoft Access 2000 DBMS and linked to corresponding ArcView applications. The current KFD of Minnesota has been moved from a Windows NT server to a Windows 2000 Citrix server accessible to researchers and planners through networked interfaces. ?? Springer-Verlag 2005.

Visible Languages for Program Visualization

DTIC Science & Technology

1986-02-01

Comments 38 The Presentation of Program Metadata 39 The Spatial Composition of Comments 41 The Typography of Punctuation 42 Typographic Encodings... Typography of Program Punctuation 6. In this example the "" appears in 10 point regular Helvetica type, and thus uses the same typographic parameters as...Results. Conclusions Chapter 4 Graphic Design of C Source Code and Comments Section 4 3 1 he Typography of Punctuation Page 41 l ft. Section

NASA's Global Change Master Directory: Discover and Access Earth Science Data Sets, Related Data Services, and Climate Diagnostics

NASA Astrophysics Data System (ADS)

Aleman, A.; Olsen, L. M.; Ritz, S.; Stevens, T.; Morahan, M.; Grebas, S. K.

2011-12-01

NASA's Global Change Master Directory provides the scientific community with the ability to discover, access, and use Earth science data, data-related services, and climate diagnostics worldwide.The GCMD offers descriptions of Earth science data sets using the Directory Interchange Format (DIF) metadata standard; Earth science related data services are described using the Service Entry Resource Format (SERF); and climate visualizations are described using the Climate Diagnostic (CD) standard. The DIF, SERF and CD standards each capture data attributes used to determine whether a data set, service, or climate visualization is relevant to a user's needs.Metadata fields include: title, summary, science keywords, service keywords, data center, data set citation, personnel, instrument, platform, quality, related URL, temporal and spatial coverage, data resolution and distribution information.In addition, nine valuable sets of controlled vocabularies have been developed to assist users in normalizing the search for data descriptions. An update to the GCMD's search functionality is planned to further capitalize on the controlled vocabularies during database queries.By implementing a dynamic keyword "tree", users will have the ability to search for data sets by combining keywords in new ways.This will allow users to conduct more relevant and efficient database searches to support the free exchange and re-use of Earth science data.

New GES DISC Services Shortening the Path in Science Data Discovery

NASA Technical Reports Server (NTRS)

Li, Angela; Shie, Chung-Lin; Petrenko, Maksym; Hegde, Mahabaleshwa; Teng, William; Liu, Zhong; Bryant, Keith; Shen, Suhung; Hearty, Thomas; Wei, Jennifer;

Visual interface for space and terrestrial analysis

NASA Technical Reports Server (NTRS)

Dombrowski, Edmund G.; Williams, Jason R.; George, Arthur A.; Heckathorn, Harry M.; Snyder, William A.

1995-01-01

The management of large geophysical and celestial data bases is now, more than ever, the most critical path to timely data analysis. With today's large volume data sets from multiple satellite missions, analysts face the task of defining useful data bases from which data and metadata (information about data) can be extracted readily in a meaningful way. Visualization, following an object-oriented design, is a fundamental method of organizing and handling data. Humans, by nature, easily accept pictorial representations of data. Therefore graphically oriented user interfaces are appealing, as long as they remain simple to produce and use. The Visual Interface for Space and Terrestrial Analysis (VISTA) system, currently under development at the Naval Research Laboratory's Backgrounds Data Center (BDC), has been designed with these goals in mind. Its graphical user interface (GUI) allows the user to perform queries, visualization, and analysis of atmospheric and celestial backgrounds data.

Log-less metadata management on metadata server for parallel file systems.

PubMed

Liao, Jianwei; Xiao, Guoqiang; Peng, Xiaoning

2014-01-01

This paper presents a novel metadata management mechanism on the metadata server (MDS) for parallel and distributed file systems. In this technique, the client file system backs up the sent metadata requests, which have been handled by the metadata server, so that the MDS does not need to log metadata changes to nonvolatile storage for achieving highly available metadata service, as well as better performance improvement in metadata processing. As the client file system backs up certain sent metadata requests in its memory, the overhead for handling these backup requests is much smaller than that brought by the metadata server, while it adopts logging or journaling to yield highly available metadata service. The experimental results show that this newly proposed mechanism can significantly improve the speed of metadata processing and render a better I/O data throughput, in contrast to conventional metadata management schemes, that is, logging or journaling on MDS. Besides, a complete metadata recovery can be achieved by replaying the backup logs cached by all involved clients, when the metadata server has crashed or gone into nonoperational state exceptionally.

Log-Less Metadata Management on Metadata Server for Parallel File Systems

PubMed Central

Xiao, Guoqiang; Peng, Xiaoning

2014-01-01

This paper presents a novel metadata management mechanism on the metadata server (MDS) for parallel and distributed file systems. In this technique, the client file system backs up the sent metadata requests, which have been handled by the metadata server, so that the MDS does not need to log metadata changes to nonvolatile storage for achieving highly available metadata service, as well as better performance improvement in metadata processing. As the client file system backs up certain sent metadata requests in its memory, the overhead for handling these backup requests is much smaller than that brought by the metadata server, while it adopts logging or journaling to yield highly available metadata service. The experimental results show that this newly proposed mechanism can significantly improve the speed of metadata processing and render a better I/O data throughput, in contrast to conventional metadata management schemes, that is, logging or journaling on MDS. Besides, a complete metadata recovery can be achieved by replaying the backup logs cached by all involved clients, when the metadata server has crashed or gone into nonoperational state exceptionally. PMID:24892093

Modern classification and outcome predictors of surgery in patients with brain arteriovenous malformations.

PubMed

Tayebi Meybodi, Ali; Lawton, Michael T

2018-02-23

Brain arteriovenous malformations (bAVM) are challenging lesions. Part of this challenge stems from the infinite diversity of these lesions regarding shape, location, anatomy, and physiology. This diversity has called on a variety of treatment modalities for these lesions, of which microsurgical resection prevails as the mainstay of treatment. As such, outcome prediction and managing strategy mainly rely on unraveling the nature of these complex tangles and ways each lesion responds to various therapeutic modalities. This strategy needs the ability to decipher each lesion through accurate and efficient categorization. Therefore, classification schemes are essential parts of treatment planning and outcome prediction. This article summarizes different surgical classification schemes and outcome predictors proposed for bAVMs.

Atmospheric verification mission for the TSS/STARFAC tethered satellite

NASA Technical Reports Server (NTRS)

Wood, George M., Jr.; Stuart, Thomas D.; Crouch, Donald S.; Deloach, Richard; Brown, Kenneth G.

1991-01-01

Two types of a tethered satellite system (TSS) - a basic 1.8-m-diameter spherical spacecraft and the Shuttle Tethered Aerothermodynamic Research Facility (STARFAC) are considered. Issues related to the deployment and retrieval of a large satellite with exceedingly long tethers are discussed, and the objectives of an Atmospheric Verification Mission (ATM) are outlined. Focus is concentrated on the ATM satellite which will fly after TSS-1 and before the fully instrumented and costlier TSS-2. The differences between the AVM and TSS-2, including the configuration of the aerodynamic stabilizers, instrumentation, and the materials of construction are outlined. The basic Kevlar tether defined for the TSS-2 is being considered for use with the AVM, however, a complex tether is under consideration as well.

Community cyberinfrastructure for Advanced Microbial Ecology Research and Analysis: the CAMERA resource

PubMed Central

Sun, Shulei; Chen, Jing; Li, Weizhong; Altintas, Ilkay; Lin, Abel; Peltier, Steve; Stocks, Karen; Allen, Eric E.; Ellisman, Mark; Grethe, Jeffrey; Wooley, John

2011-01-01

The Community Cyberinfrastructure for Advanced Microbial Ecology Research and Analysis (CAMERA, http://camera.calit2.net/) is a database and associated computational infrastructure that provides a single system for depositing, locating, analyzing, visualizing and sharing data about microbial biology through an advanced web-based analysis portal. CAMERA collects and links metadata relevant to environmental metagenome data sets with annotation in a semantically-aware environment allowing users to write expressive semantic queries against the database. To meet the needs of the research community, users are able to query metadata categories such as habitat, sample type, time, location and other environmental physicochemical parameters. CAMERA is compliant with the standards promulgated by the Genomic Standards Consortium (GSC), and sustains a role within the GSC in extending standards for content and format of the metagenomic data and metadata and its submission to the CAMERA repository. To ensure wide, ready access to data and annotation, CAMERA also provides data submission tools to allow researchers to share and forward data to other metagenomics sites and community data archives such as GenBank. It has multiple interfaces for easy submission of large or complex data sets, and supports pre-registration of samples for sequencing. CAMERA integrates a growing list of tools and viewers for querying, analyzing, annotating and comparing metagenome and genome data. PMID:21045053

Community cyberinfrastructure for Advanced Microbial Ecology Research and Analysis: the CAMERA resource.

PubMed

Sun, Shulei; Chen, Jing; Li, Weizhong; Altintas, Ilkay; Lin, Abel; Peltier, Steve; Stocks, Karen; Allen, Eric E; Ellisman, Mark; Grethe, Jeffrey; Wooley, John

2011-01-01

The Community Cyberinfrastructure for Advanced Microbial Ecology Research and Analysis (CAMERA, http://camera.calit2.net/) is a database and associated computational infrastructure that provides a single system for depositing, locating, analyzing, visualizing and sharing data about microbial biology through an advanced web-based analysis portal. CAMERA collects and links metadata relevant to environmental metagenome data sets with annotation in a semantically-aware environment allowing users to write expressive semantic queries against the database. To meet the needs of the research community, users are able to query metadata categories such as habitat, sample type, time, location and other environmental physicochemical parameters. CAMERA is compliant with the standards promulgated by the Genomic Standards Consortium (GSC), and sustains a role within the GSC in extending standards for content and format of the metagenomic data and metadata and its submission to the CAMERA repository. To ensure wide, ready access to data and annotation, CAMERA also provides data submission tools to allow researchers to share and forward data to other metagenomics sites and community data archives such as GenBank. It has multiple interfaces for easy submission of large or complex data sets, and supports pre-registration of samples for sequencing. CAMERA integrates a growing list of tools and viewers for querying, analyzing, annotating and comparing metagenome and genome data.

Expressive map design: OGC SLD/SE++ extension for expressive map styles

NASA Astrophysics Data System (ADS)

Christophe, Sidonie; Duménieu, Bertrand; Masse, Antoine; Hoarau, Charlotte; Ory, Jérémie; Brédif, Mathieu; Lecordix, François; Mellado, Nicolas; Turbet, Jérémie; Loi, Hugo; Hurtut, Thomas; Vanderhaeghe, David; Vergne, Romain; Thollot, Joëlle

2018-05-01

In the context of custom map design, handling more artistic and expressive tools has been identified as a carto-graphic need, in order to design stylized and expressive maps. Based on previous works on style formalization, an approach for specifying the map style has been proposed and experimented for particular use cases. A first step deals with the analysis of inspiration sources, in order to extract `what does make the style of the source', i.e. the salient visual characteristics to be automatically reproduced (textures, spatial arrangements, linear stylization, etc.). In a second step, in order to mimic and generate those visual characteristics, existing and innovative rendering techniques have been implemented in our GIS engine, thus extending the capabilities to generate expressive renderings. Therefore, an extension of the existing cartographic pipeline has been proposed based on the following aspects: 1- extension of the symbolization specifications OGC SLD/SE in order to provide a formalism to specify and reference expressive rendering methods; 2- separate the specification of each rendering method and its parameterization, as metadata. The main contribution has been described in (Christophe et al. 2016). In this paper, we focus firstly on the extension of the cartographic pipeline (SLD++ and metadata) and secondly on map design capabilities which have been experimented on various topographic styles: old cartographic styles (Cassini), artistic styles (watercolor, impressionism, Japanese print), hybrid topographic styles (ortho-imagery & vector data) and finally abstract and photo-realist styles for the geovisualization of costal area. The genericity and interoperability of our approach are promising and have already been tested for 3D visualization.

MeRy-B: a web knowledgebase for the storage, visualization, analysis and annotation of plant NMR metabolomic profiles

PubMed Central

2011-01-01

Background Improvements in the techniques for metabolomics analyses and growing interest in metabolomic approaches are resulting in the generation of increasing numbers of metabolomic profiles. Platforms are required for profile management, as a function of experimental design, and for metabolite identification, to facilitate the mining of the corresponding data. Various databases have been created, including organism-specific knowledgebases and analytical technique-specific spectral databases. However, there is currently no platform meeting the requirements for both profile management and metabolite identification for nuclear magnetic resonance (NMR) experiments. Description MeRy-B, the first platform for plant 1H-NMR metabolomic profiles, is designed (i) to provide a knowledgebase of curated plant profiles and metabolites obtained by NMR, together with the corresponding experimental and analytical metadata, (ii) for queries and visualization of the data, (iii) to discriminate between profiles with spectrum visualization tools and statistical analysis, (iv) to facilitate compound identification. It contains lists of plant metabolites and unknown compounds, with information about experimental conditions, the factors studied and metabolite concentrations for several plant species, compiled from more than one thousand annotated NMR profiles for various organs or tissues. Conclusion MeRy-B manages all the data generated by NMR-based plant metabolomics experiments, from description of the biological source to identification of the metabolites and determinations of their concentrations. It is the first database allowing the display and overlay of NMR metabolomic profiles selected through queries on data or metadata. MeRy-B is available from http://www.cbib.u-bordeaux2.fr/MERYB/index.php. PMID:21668943

Brain AVM (Arteriovenous Malformation)

MedlinePlus

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[The clinico-neuropsychological aspects of arteriovenous malformations of the hippocampus].

PubMed

Buklina, S B; Filatov, Iu M; Eliava, Sh Sh

1998-01-01

A comprehensive examination was made in 39 patients with arteriovenous malformations (AVM) of hippocampus. Prior to and following surgery, all the patients underwent neuropsychological study after A. R. Luriia (1962). Mnestic disorder was found to be the most common abnormality in patients with AVM at this site. Before surgery, they were detected in 34 of 39 patients, 11 of them having severe memory disorders with the traits of the Korsakoff's syndrome. These patients were found to have mixed posthemorrhagic lesion of the hippocampus, other portions of the temporal lobe and periventricular structures. Twenty nine patients were operated on, 14 of them had progressive mnestic disorder of the modally nonspecific type irrespective the side operated on. There were no postoperative Korsakoff's syndromes. There was no progression in memory defects in patients after surgery on the brain drastically changed after hemorrhage or removal of minor malformations. Before hemorrhage, epileptic paroxysms were observed in 2 of the 39 patients only in the presence of massive AVM obligatorily involving the temporal cortex. Following surgery, there were no new epileptic paroxysms and changes in the emotional status and motivations in the patients. Thus, the hippocampal formation is involved in the primary mechanisms of fixation, retention, reproduction of a memory trace. The participation of many structures of the brain is required to form an emotional status, motivation, and clinical manifestations of epileptic activity.

Appreciating the broad clinical features of SMAD4 mutation carriers: a multi-center chart review

PubMed Central

Wain, K.E.; Ellingson, M.S.; McDonald, J.; Gammon, A.; Roberts, M.; Pichurin, P.; Winship, I.; Riegert-Johnson, D.; Weitzel, J. N.; Lindor, N.M.

2014-01-01

Heterozygous loss-of-function (LOF) SMAD4 mutations are associated with juvenile polyposis syndrome (JP) and hereditary hemorrhagic telangiectasia (HHT). Some carriers exhibit symptoms of both conditions, leading to the name JP-HHT syndrome. Three families have been reported with connective tissue abnormalities. In order to better understand the spectrum and extent of clinical findings in SMAD4 carriers, medical records of 34 patients (20 families) from five clinical practices were reviewed. Twenty-one percent (7/34) had features suggesting a connective tissue defect: enlarged aortic root (n=3), aortic and mitral insufficiency (n=2), aortic dissection (n=1), retinal detachment (n=1), brain aneurysms (n=1), lax skin and joints (n=1). JP-specific findings were almost uniformly present but variable. Ninety-seven percent had colon polyps that were generally pan-colonic and of variable histology and number. Forty-eight percent (15/31) had extensive gastric polyposis. HHT features were documented in 76% including epistaxis (19/31, 61%), mucocutaneous telangiectases (15/31, 48%), liver arteriovenous malformation (AVM) (6/16, 38%), brain AVM (1/26, 4%), pulmonary AVM (9/17, 53%), and intrapulmonary shunting (14/23, 61%). SMAD4 carriers should be managed for JP and HHT, since symptoms of both are likely yet unpredictable. Connective tissue abnormalities are an emerging component of JP-HHT syndrome, and larger studies are needed to understand these manifestations. PMID:24525918

Computer simulation of Cerebral Arteriovenous Malformation-validation analysis of hemodynamics parameters.

PubMed

Kumar, Y Kiran; Mehta, Shashi Bhushan; Ramachandra, Manjunath

2017-01-01

The purpose of this work is to provide some validation methods for evaluating the hemodynamic assessment of Cerebral Arteriovenous Malformation (CAVM). This article emphasizes the importance of validating noninvasive measurements for CAVM patients, which are designed using lumped models for complex vessel structure. The validation of the hemodynamics assessment is based on invasive clinical measurements and cross-validation techniques with the Philips proprietary validated software's Qflow and 2D Perfursion. The modeling results are validated for 30 CAVM patients for 150 vessel locations. Mean flow, diameter, and pressure were compared between modeling results and with clinical/cross validation measurements, using an independent two-tailed Student t test. Exponential regression analysis was used to assess the relationship between blood flow, vessel diameter, and pressure between them. Univariate analysis is used to assess the relationship between vessel diameter, vessel cross-sectional area, AVM volume, AVM pressure, and AVM flow results were performed with linear or exponential regression. Modeling results were compared with clinical measurements from vessel locations of cerebral regions. Also, the model is cross validated with Philips proprietary validated software's Qflow and 2D Perfursion. Our results shows that modeling results and clinical results are nearly matching with a small deviation. In this article, we have validated our modeling results with clinical measurements. The new approach for cross-validation is proposed by demonstrating the accuracy of our results with a validated product in a clinical environment.

Visualizing Uncertainty for Data Fusion Graphics: Review of Selected Literature and Industry Approaches

DTIC Science & Technology

2015-06-09

anomaly detection , which is generally considered part of high level information fusion (HLIF) involving temporal-geospatial data as well as meta-data... Anomaly detection in the Maritime defence and security domain typically focusses on trying to identify vessels that are behaving in an unusual...manner compared with lawful vessels operating in the area – an applied case of target detection among distractors. Anomaly detection is a complex problem

Metadata for Web Resources: How Metadata Works on the Web.

ERIC Educational Resources Information Center

Dillon, Martin

This paper discusses bibliographic control of knowledge resources on the World Wide Web. The first section sets the context of the inquiry. The second section covers the following topics related to metadata: (1) definitions of metadata, including metadata as tags and as descriptors; (2) metadata on the Web, including general metadata systems,…

Metadata Dictionary Database: A Proposed Tool for Academic Library Metadata Management

ERIC Educational Resources Information Center

Southwick, Silvia B.; Lampert, Cory

2011-01-01

This article proposes a metadata dictionary (MDD) be used as a tool for metadata management. The MDD is a repository of critical data necessary for managing metadata to create "shareable" digital collections. An operational definition of metadata management is provided. The authors explore activities involved in metadata management in…

Fast and Accurate Metadata Authoring Using Ontology-Based Recommendations.

PubMed

Martínez-Romero, Marcos; O'Connor, Martin J; Shankar, Ravi D; Panahiazar, Maryam; Willrett, Debra; Egyedi, Attila L; Gevaert, Olivier; Graybeal, John; Musen, Mark A

2017-01-01

In biomedicine, high-quality metadata are crucial for finding experimental datasets, for understanding how experiments were performed, and for reproducing those experiments. Despite the recent focus on metadata, the quality of metadata available in public repositories continues to be extremely poor. A key difficulty is that the typical metadata acquisition process is time-consuming and error prone, with weak or nonexistent support for linking metadata to ontologies. There is a pressing need for methods and tools to speed up the metadata acquisition process and to increase the quality of metadata that are entered. In this paper, we describe a methodology and set of associated tools that we developed to address this challenge. A core component of this approach is a value recommendation framework that uses analysis of previously entered metadata and ontology-based metadata specifications to help users rapidly and accurately enter their metadata. We performed an initial evaluation of this approach using metadata from a public metadata repository.

Fast and Accurate Metadata Authoring Using Ontology-Based Recommendations

PubMed Central

Martínez-Romero, Marcos; O’Connor, Martin J.; Shankar, Ravi D.; Panahiazar, Maryam; Willrett, Debra; Egyedi, Attila L.; Gevaert, Olivier; Graybeal, John; Musen, Mark A.

2017-01-01

In biomedicine, high-quality metadata are crucial for finding experimental datasets, for understanding how experiments were performed, and for reproducing those experiments. Despite the recent focus on metadata, the quality of metadata available in public repositories continues to be extremely poor. A key difficulty is that the typical metadata acquisition process is time-consuming and error prone, with weak or nonexistent support for linking metadata to ontologies. There is a pressing need for methods and tools to speed up the metadata acquisition process and to increase the quality of metadata that are entered. In this paper, we describe a methodology and set of associated tools that we developed to address this challenge. A core component of this approach is a value recommendation framework that uses analysis of previously entered metadata and ontology-based metadata specifications to help users rapidly and accurately enter their metadata. We performed an initial evaluation of this approach using metadata from a public metadata repository. PMID:29854196

linkedISA: semantic representation of ISA-Tab experimental metadata.

PubMed

González-Beltrán, Alejandra; Maguire, Eamonn; Sansone, Susanna-Assunta; Rocca-Serra, Philippe

2014-01-01

Reporting and sharing experimental metadata- such as the experimental design, characteristics of the samples, and procedures applied, along with the analysis results, in a standardised manner ensures that datasets are comprehensible and, in principle, reproducible, comparable and reusable. Furthermore, sharing datasets in formats designed for consumption by humans and machines will also maximize their use. The Investigation/Study/Assay (ISA) open source metadata tracking framework facilitates standards-compliant collection, curation, visualization, storage and sharing of datasets, leveraging on other platforms to enable analysis and publication. The ISA software suite includes several components used in increasingly diverse set of life science and biomedical domains; it is underpinned by a general-purpose format, ISA-Tab, and conversions exist into formats required by public repositories. While ISA-Tab works well mainly as a human readable format, we have also implemented a linked data approach to semantically define the ISA-Tab syntax. We present a semantic web representation of the ISA-Tab syntax that complements ISA-Tab's syntactic interoperability with semantic interoperability. We introduce the linkedISA conversion tool from ISA-Tab to the Resource Description Framework (RDF), supporting mappings from the ISA syntax to multiple community-defined, open ontologies and capitalising on user-provided ontology annotations in the experimental metadata. We describe insights of the implementation and how annotations can be expanded driven by the metadata. We applied the conversion tool as part of Bio-GraphIIn, a web-based application supporting integration of the semantically-rich experimental descriptions. Designed in a user-friendly manner, the Bio-GraphIIn interface hides most of the complexities to the users, exposing a familiar tabular view of the experimental description to allow seamless interaction with the RDF representation, and visualising descriptors to drive the query over the semantic representation of the experimental design. In addition, we defined queries over the linkedISA RDF representation and demonstrated its use over the linkedISA conversion of datasets from Nature' Scientific Data online publication. Our linked data approach has allowed us to: 1) make the ISA-Tab semantics explicit and machine-processable, 2) exploit the existing ontology-based annotations in the ISA-Tab experimental descriptions, 3) augment the ISA-Tab syntax with new descriptive elements, 4) visualise and query elements related to the experimental design. Reasoning over ISA-Tab metadata and associated data will facilitate data integration and knowledge discovery.

Integrating Ideas for International Data Collaborations Through The Committee on Earth Observation Satellites (CEOS) International Directory Network (IDN)

NASA Technical Reports Server (NTRS)

Olsen, Lola M.

2006-01-01

The capabilities of the International Directory Network's (IDN) version MD9.5, along with a new version of the metadata authoring tool, "docBUILDER", will be presented during the Technology and Services Subgroup session of the Working Group on Information Systems and Services (WGISS). Feedback provided through the international community has proven instrumental in positively influencing the direction of the IDN s development. The international community was instrumental in encouraging support for using the IS0 international character set that is now available through the directory. Supporting metadata descriptions in additional languages encourages extended use of the IDN. Temporal and spatial attributes often prove pivotal in the search for data. Prior to the new software release, the IDN s geospatial and temporal searches suffered from browser incompatibilities and often resulted in unreliable performance for users attempting to initiate a spatial search using a map based on aging Java applet technology. The IDN now offers an integrated Google map and date search that replaces that technology. In addition, one of the most defining characteristics in the search for data relates to the temporal and spatial resolution of the data. The ability to refine the search for data sets meeting defined resolution requirements is now possible. Data set authors are encouraged to indicate the precise resolution values for their data sets and subsequently bin these into one of the pre-selected resolution ranges. New metadata authoring tools have been well received. In response to requests for a standalone metadata authoring tool, a new shareable software package called "docBUILDER solo" will soon be released to the public. This tool permits researchers to document their data during experiments and observational periods in the field. interoperability has been enhanced through the use of the Open Archives Initiative s (OAI) Protocol for Metadata Harvesting (PMH). Harvesting of XML content through OAI-MPH has been successfully tested with several organizations. The protocol appears to be a prime candidate for sharing metadata throughout the international community. Data services for visualizing and analyzing data have become valuable assets in facilitating the use of data. Data providers are offering many of their data-related services through the directory. The IDN plans to develop a service-based architecture to further promote the use of web services. During the IDN Task Team session, ideas for further enhancements will be discussed.

Harvesting NASA's Common Metadata Repository (CMR)

NASA Technical Reports Server (NTRS)

Shum, Dana; Durbin, Chris; Norton, James; Mitchell, Andrew

2017-01-01

As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

Harvesting NASA's Common Metadata Repository

NASA Astrophysics Data System (ADS)

Shum, D.; Mitchell, A. E.; Durbin, C.; Norton, J.

2017-12-01

As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

New Solutions for Enabling Discovery of User-Centric Virtual Data Products in NASA's Common Metadata Repository

NASA Astrophysics Data System (ADS)

Pilone, D.; Gilman, J.; Baynes, K.; Shum, D.

2015-12-01

This talk introduces a new NASA Earth Observing System Data and Information System (EOSDIS) capability to automatically generate and maintain derived, Virtual Product information allowing DAACs and Data Providers to create tailored and more discoverable variations of their products. After this talk the audience will be aware of the new EOSDIS Virtual Product capability, applications of it, and how to take advantage of it. Much of the data made available in the EOSDIS are organized for generation and archival rather than for discovery and use. The EOSDIS Common Metadata Repository (CMR) is launching a new capability providing automated generation and maintenance of user-oriented Virtual Product information. DAACs can easily surface variations on established data products tailored to specific uses cases and users, leveraging DAAC exposed services such as custom ordering or access services like OPeNDAP for on-demand product generation and distribution. Virtual Data Products enjoy support for spatial and temporal information, keyword discovery, association with imagery, and are fully discoverable by tools such as NASA Earthdata Search, Worldview, and Reverb. Virtual Product generation has applicability across many use cases: - Describing derived products such as Surface Kinetic Temperature information (AST_08) from source products (ASTER L1A) - Providing streamlined access to data products (e.g. AIRS) containing many (>800) data variables covering an enormous variety of physical measurements - Attaching additional EOSDIS offerings such as Visual Metadata, external services, and documentation metadata - Publishing alternate formats for a product (e.g. netCDF for HDF products) with the actual conversion happening on request - Publishing granules to be modified by on-the-fly services, like GES-DISC's Data Quality Screening Service - Publishing "bundled" products where granules from one product correspond to granules from one or more other related products

User Centered, Application Independent Visualization of National Airspace Data

NASA Technical Reports Server (NTRS)

Murphy, James R.; Hinton, Susan E.

2011-01-01

This paper describes an application independent software tool, IV4D, built to visualize animated and still 3D National Airspace System (NAS) data specifically for aeronautics engineers who research aggregate, as well as single, flight efficiencies and behavior. IV4D was origin ally developed in a joint effort between the National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (A FRL) to support the visualization of air traffic data from the Airspa ce Concept Evaluation System (ACES) simulation program. The three mai n challenges tackled by IV4D developers were: 1) determining how to d istill multiple NASA data formats into a few minimal dataset types; 2 ) creating an environment, consisting of a user interface, heuristic algorithms, and retained metadata, that facilitates easy setup and fa st visualization; and 3) maximizing the user?s ability to utilize the extended range of visualization available with AFRL?s existing 3D te chnologies. IV4D is currently being used by air traffic management re searchers at NASA?s Ames and Langley Research Centers to support data visualizations.

Data System for HS3 Airborne Field Campaign

NASA Astrophysics Data System (ADS)

Maskey, M.; Mceniry, M.; Berendes, T.; Bugbee, K.; Conover, H.; Ramachandran, R.

2014-12-01

Hurricane and Severe Storm Sentinel (HS3) is a NASA airborne field campaign aimed at better understanding the physical processes that control hurricane intensity change. HS3 will help answer questions related to the roles of environmental conditions and internal storm structures to storm intensification. Due to the nature of the questions that HS3 mission is addressing, it involves a variety of in-situ, satellite observations, airborne data, meteorological analyses, and simulation data. This variety of datasets presents numerous data management challenges for HS3. The methods used for airborne data management differ greatly from the methods used for space-borne data. In particular, metadata extraction, spatial and temporal indexing, and the large number of instruments and subsequent variables are a few of the data management challenges unique to airborne missions. A robust data system is required to successfully help HS3 scientist achieve their mission goals. Furthermore, the data system also needs to provide for data management that assists in broader use of HS3 data to enable future research activities. The Global Hydrology Resource Center (GHRC) is considering all these needs and designing a data system for HS3. Experience with past airborne field campaign puts GHRC in a good position to address HS3 needs. However, the scale of this mission along with science requirements separates HS3 from previous field campaigns. The HS3 data system will include automated services for geo-location, metadata extraction, discovery, and distribution for all HS3 data. To answer the science questions, the data system will include a visual data exploration tool that is fully integrated into the data catalog. The tool will allow visually augmenting airborne data with analyses and simulations. Satellite data will provide contextual information during such data explorations. All HS3 tools will be supported by an enterprise service architecture that will allow scaling, easy integration of new tools and existing services, and integration of new ESDIS metadata and security guidelines.

Distributed data discovery, access and visualization services to Improve Data Interoperability across different data holdings

NASA Astrophysics Data System (ADS)

Palanisamy, G.; Krassovski, M.; Devarakonda, R.; Santhana Vannan, S.

2012-12-01

The current climate debate is highlighting the importance of free, open, and authoritative sources of high quality climate data that are available for peer review and for collaborative purposes. It is increasingly important to allow various organizations around the world to share climate data in an open manner, and to enable them to perform dynamic processing of climate data. This advanced access to data can be enabled via Web-based services, using common "community agreed" standards without having to change their internal structure used to describe the data. The modern scientific community has become diverse and increasingly complex in nature. To meet the demands of such diverse user community, the modern data supplier has to provide data and other related information through searchable, data and process oriented tool. This can be accomplished by setting up on-line, Web-based system with a relational database as a back end. The following common features of the web data access/search systems will be outlined in the proposed presentation: - A flexible data discovery - Data in commonly used format (e.g., CSV, NetCDF) - Preparing metadata in standard formats (FGDC, ISO19115, EML, DIF etc.) - Data subseting capabilities and ability to narrow down to individual data elements - Standards based data access protocols and mechanisms (SOAP, REST, OpenDAP, OGC etc.) - Integration of services across different data systems (discovery to access, visualizations and subseting) This presentation will also include specific examples of integration of various data systems that are developed by Oak Ridge National Laboratory's - Climate Change Science Institute, their ability to communicate between each other to enable better data interoperability and data integration. References: [1] Devarakonda, Ranjeet, and Harold Shanafield. "Drupal: Collaborative framework for science research." Collaboration Technologies and Systems (CTS), 2011 International Conference on. IEEE, 2011. [2]Devarakonda, R., Shrestha, B., Palanisamy, G., Hook, L. A., Killeffer, T. S., Boden, T. A., ... & Lazer, K. (2014). THE NEW ONLINE METADATA EDITOR FOR GENERATING STRUCTURED METADATA. Oak Ridge National Laboratory (ORNL).

Annotation of rule-based models with formal semantics to enable creation, analysis, reuse and visualization.

PubMed

Misirli, Goksel; Cavaliere, Matteo; Waites, William; Pocock, Matthew; Madsen, Curtis; Gilfellon, Owen; Honorato-Zimmer, Ricardo; Zuliani, Paolo; Danos, Vincent; Wipat, Anil

2016-03-15

Biological systems are complex and challenging to model and therefore model reuse is highly desirable. To promote model reuse, models should include both information about the specifics of simulations and the underlying biology in the form of metadata. The availability of computationally tractable metadata is especially important for the effective automated interpretation and processing of models. Metadata are typically represented as machine-readable annotations which enhance programmatic access to information about models. Rule-based languages have emerged as a modelling framework to represent the complexity of biological systems. Annotation approaches have been widely used for reaction-based formalisms such as SBML. However, rule-based languages still lack a rich annotation framework to add semantic information, such as machine-readable descriptions, to the components of a model. We present an annotation framework and guidelines for annotating rule-based models, encoded in the commonly used Kappa and BioNetGen languages. We adapt widely adopted annotation approaches to rule-based models. We initially propose a syntax to store machine-readable annotations and describe a mapping between rule-based modelling entities, such as agents and rules, and their annotations. We then describe an ontology to both annotate these models and capture the information contained therein, and demonstrate annotating these models using examples. Finally, we present a proof of concept tool for extracting annotations from a model that can be queried and analyzed in a uniform way. The uniform representation of the annotations can be used to facilitate the creation, analysis, reuse and visualization of rule-based models. Although examples are given, using specific implementations the proposed techniques can be applied to rule-based models in general. The annotation ontology for rule-based models can be found at http://purl.org/rbm/rbmo The krdf tool and associated executable examples are available at http://purl.org/rbm/rbmo/krdf anil.wipat@newcastle.ac.uk or vdanos@inf.ed.ac.uk. © The Author 2015. Published by Oxford University Press.

[Venous and arteriovenous malformations in the head and neck region. Therapeutic options and challenges].

PubMed

Eivazi, B; Werner, J A

2014-01-01

Venous malformations are the prototype low-flow malformations in the head and neck region. Arteriovenous malformations (AVM) represent the main high-flow malformations. In recent years it has been possible to significantly optimize the therapeutic options for venous malformations. In addition to conventional surgery, laser treatment and sclerotherapy have become established techniques and the importance of embolization with new alcohol-based materials is increasing. AVM are progressive and destructive diseases. Therapy of choice is usually a combined treatment comprising embolization and surgical removal of the arteriovenous nidus. This curative approach is usually possible if diagnosis is made at an early stage. Incomplete embolization or sole ligation of the arterial supply causes progression. There is a clear need for improved therapeutic methods and pharmacotherapeutic approaches.

GazeAppraise v. 0.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Andrew; Haass, Michael; Rintoul, Mark Daniel

GazeAppraise advances the state of the art of gaze pattern analysis using methods that simultaneously analyze spatial and temporal characteristics of gaze patterns. GazeAppraise enables novel research in visual perception and cognition; for example, using shape features as distinguishing elements to assess individual differences in visual search strategy. Given a set of point-to-point gaze sequences, hereafter referred to as scanpaths, the method constructs multiple descriptive features for each scanpath. Once the scanpath features have been calculated, they are used to form a multidimensional vector representing each scanpath and cluster analysis is performed on the set of vectors from all scanpaths.more » An additional benefit of this method is the identification of causal or correlated characteristics of the stimuli, subjects, and visual task through statistical analysis of descriptive metadata distributions within and across clusters.« less

ResistoMap-online visualization of human gut microbiota antibiotic resistome.

PubMed

Yarygin, Konstantin S; Kovarsky, Boris A; Bibikova, Tatyana S; Melnikov, Damir S; Tyakht, Alexander V; Alexeev, Dmitry G

2017-07-15

We created ResistoMap—a Web-based interactive visualization of the presence of genetic determinants conferring resistance to antibiotics, biocides and heavy metals in human gut microbiota. ResistoMap displays the data on more than 1500 published gut metagenomes of world populations including both healthy subjects and patients. Multiparameter display filters allow visual assessment of the associations between the meta-data and proportions of resistome. The geographic map navigation layer allows to state hypotheses regarding the global trends of antibiotic resistance and correlates the gut resistome variations with the national clinical guidelines on antibiotics application. ResistoMap was implemented using AngularJS, CoffeeScript, D3.js and TopoJSON. The tool is publicly available at http://resistomap.rcpcm.org. yarygin@phystech.edu. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

HTML5 PivotViewer: high-throughput visualization and querying of image data on the web

PubMed Central

Taylor, Stephen; Noble, Roger

2014-01-01

Motivation: Visualization and analysis of large numbers of biological images has generated a bottle neck in research. We present HTML5 PivotViewer, a novel, open source, platform-independent viewer making use of the latest web technologies that allows seamless access to images and associated metadata for each image. This provides a powerful method to allow end users to mine their data. Availability and implementation: Documentation, examples and links to the software are available from http://www.cbrg.ox.ac.uk/data/pivotviewer/. The software is licensed under GPLv2. Contact:  stephen.taylor@imm.ox.ac.uk and roger@coritsu.com PMID:24849578

Nature's Notebook 2010: Data & participant summary

USGS Publications Warehouse

Crimmins, Theresa M.; Rosemartin, Alyssa H.; Marsh, R. Lee; Denny, Ellen G.; Enquist, Carolyn A.F.; Weltzin, Jake F.

2011-01-01

Data submitted by Nature’s Notebook participants show patterns that follow latitude and elevation. Multiple years of observations now allow for year‐to‐year comparisons within and across species. As such, these data should be useful to a variety of stakeholders interested in the spatial and temporal patterns of plant and animal activity on a national scale; through time, these data should also empower scientists, resource managers, and the public in decision‐making and adapting to variable and changing climates and environments. Data submitted toNature’s Notebook and supporting metadata are available for download at www.usanpn.org/results/data. Additionally, data visualization tools are available online at www.usanpn.org/results/visualizations.

Simplified Metadata Curation via the Metadata Management Tool

NASA Astrophysics Data System (ADS)

Shum, D.; Pilone, D.

2015-12-01

The Metadata Management Tool (MMT) is the newest capability developed as part of NASA Earth Observing System Data and Information System's (EOSDIS) efforts to simplify metadata creation and improve metadata quality. The MMT was developed via an agile methodology, taking into account inputs from GCMD's science coordinators and other end-users. In its initial release, the MMT uses the Unified Metadata Model for Collections (UMM-C) to allow metadata providers to easily create and update collection records in the ISO-19115 format. Through a simplified UI experience, metadata curators can create and edit collections without full knowledge of the NASA Best Practices implementation of ISO-19115 format, while still generating compliant metadata. More experienced users are also able to access raw metadata to build more complex records as needed. In future releases, the MMT will build upon recent work done in the community to assess metadata quality and compliance with a variety of standards through application of metadata rubrics. The tool will provide users with clear guidance as to how to easily change their metadata in order to improve their quality and compliance. Through these features, the MMT allows data providers to create and maintain compliant and high quality metadata in a short amount of time.

International Radiosurgery Support Association

MedlinePlus

... Tumors Brain Disorders AVMs Radiosurgery Gamma Knife Linac Radiotherapy Overview Childhood Brain Tumors Radiation Therapy Radiation Injury ... Guideline Trigeminal Neuralgia | TN Guideline ... conventional x-ray imaging procedures [New England Journal of Medicine] Read ...

Assessing Metadata Quality of a Federally Sponsored Health Data Repository.

PubMed

Marc, David T; Beattie, James; Herasevich, Vitaly; Gatewood, Laël; Zhang, Rui

2016-01-01

The U.S. Federal Government developed HealthData.gov to disseminate healthcare datasets to the public. Metadata is provided for each datasets and is the sole source of information to find and retrieve data. This study employed automated quality assessments of the HealthData.gov metadata published from 2012 to 2014 to measure completeness, accuracy, and consistency of applying standards. The results demonstrated that metadata published in earlier years had lower completeness, accuracy, and consistency. Also, metadata that underwent modifications following their original creation were of higher quality. HealthData.gov did not uniformly apply Dublin Core Metadata Initiative to the metadata, which is a widely accepted metadata standard. These findings suggested that the HealthData.gov metadata suffered from quality issues, particularly related to information that wasn't frequently updated. The results supported the need for policies to standardize metadata and contributed to the development of automated measures of metadata quality.

Assessing Metadata Quality of a Federally Sponsored Health Data Repository

PubMed Central

Marc, David T.; Beattie, James; Herasevich, Vitaly; Gatewood, Laël; Zhang, Rui

2016-01-01

The U.S. Federal Government developed HealthData.gov to disseminate healthcare datasets to the public. Metadata is provided for each datasets and is the sole source of information to find and retrieve data. This study employed automated quality assessments of the HealthData.gov metadata published from 2012 to 2014 to measure completeness, accuracy, and consistency of applying standards. The results demonstrated that metadata published in earlier years had lower completeness, accuracy, and consistency. Also, metadata that underwent modifications following their original creation were of higher quality. HealthData.gov did not uniformly apply Dublin Core Metadata Initiative to the metadata, which is a widely accepted metadata standard. These findings suggested that the HealthData.gov metadata suffered from quality issues, particularly related to information that wasn’t frequently updated. The results supported the need for policies to standardize metadata and contributed to the development of automated measures of metadata quality. PMID:28269883

Partnerships To Mine Unexploited Sources of Metadata.

ERIC Educational Resources Information Center

Reynolds, Regina Romano

This paper discusses the metadata created for other purposes as a potential source of bibliographic data. The first section addresses collecting metadata by means of templates, including the Nordic Metadata Project's Dublin Core Metadata Template. The second section considers potential partnerships for re-purposing metadata for bibliographic use,…

Endovascular treatment of brain arteriovenous malformations with prolonged intranidal Onyx injection technique: long-term results in 350 consecutive patients with completed endovascular treatment course.

PubMed

Saatci, Isil; Geyik, Serdar; Yavuz, Kivilcim; Cekirge, H Saruhan

2011-07-01

The purpose of this study was to present the authors' clinical experience and long-term angiographic and clinical follow-up results in 350 patients with brain arteriovenous malformations (AVMs) treated using prolonged intranidal Onyx injection with a very slow "staged" reflux technique described by the authors. Three hundred and fifty consecutive patients with brain AVMs treated using Onyx between 1999 and 2008 and in whom definitive status for endovascular treatment was reached are presented. There were 206 (59%) male and 144 (41%) female patients, with a mean age of 34 years. There were 607 endovascular sessions performed. Onyx was the only agent used for intranidal injections in all patients, but in 42 patients high-concentration N-butyl cyanoacrylate glue was used adjunctively to close high-flow direct arteriovenous intra- or perinidal fistulas, or when a feeding vessel or nidus perforation and/or dissection occurred. Angiographically confirmed obliteration was achieved in 179 patients (51%) with only endovascular treatment; 1 patient died due to intracranial hemorrhage after the treatment. Twenty-two patients underwent resection, and 136 patients were sent to radiosurgery after endovascular treatment. In 4 patients embolization therapy was discontinued, and 5 additional patients refused the suggested complementary surgery. In all 178 surviving patients who had angiographically confirmed AVM obliteration by embolization alone, 1-8 years of control angiography (mean 47 months) confirmed stable obliteration, except for 2 patients in whom a very small recruitment was noted in the 1st year on control angiography studies, despite initial apparent total obliteration (recanalization rate 1.1%). In the entire series, 5 patients died; the mortality rate was 1.4%. The permanent morbidity rate was 7.1%. With the prolonged intranidal injection technique described herein, Onyx allows the practitioner to achieve higher rates of anatomical cures compared with the cure rates obtained previously with other embolic agents. More importantly, due to this technique's much more effective intranidal penetration, it allows high-grade AVMs to be made radiosurgically treatable in a group of patients for whom there has been no treatment alternative.

Facilitating Decision Making, Re-Use and Collaboration: A Knowledge Management Approach to Acquisition Program Self-Awareness

DTIC Science & Technology

2009-06-01

capabilities: web-based, relational/multi-dimensional, client/server, and metadata (data about data) inclusion (pp. 39-40). Text mining, on the other...and Organizational Systems ( CASOS ) (Carley, 2005). Although AutoMap can be used to conduct text-mining, it was utilized only for its visualization...provides insight into how the GMCOI is using the terms, and where there might be redundant terms and need for de -confliction and standardization

Enhanced annotations and features for comparing thousands of Pseudomonas genomes in the Pseudomonas genome database.

PubMed

Winsor, Geoffrey L; Griffiths, Emma J; Lo, Raymond; Dhillon, Bhavjinder K; Shay, Julie A; Brinkman, Fiona S L

2016-01-04

The Pseudomonas Genome Database (http://www.pseudomonas.com) is well known for the application of community-based annotation approaches for producing a high-quality Pseudomonas aeruginosa PAO1 genome annotation, and facilitating whole-genome comparative analyses with other Pseudomonas strains. To aid analysis of potentially thousands of complete and draft genome assemblies, this database and analysis platform was upgraded to integrate curated genome annotations and isolate metadata with enhanced tools for larger scale comparative analysis and visualization. Manually curated gene annotations are supplemented with improved computational analyses that help identify putative drug targets and vaccine candidates or assist with evolutionary studies by identifying orthologs, pathogen-associated genes and genomic islands. The database schema has been updated to integrate isolate metadata that will facilitate more powerful analysis of genomes across datasets in the future. We continue to place an emphasis on providing high-quality updates to gene annotations through regular review of the scientific literature and using community-based approaches including a major new Pseudomonas community initiative for the assignment of high-quality gene ontology terms to genes. As we further expand from thousands of genomes, we plan to provide enhancements that will aid data visualization and analysis arising from whole-genome comparative studies including more pan-genome and population-based approaches. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

NASA's Global Change Master Directory: Discover and Access Earth Science Data Sets, Related Data Services, and Climate Diagnostics

NASA Technical Reports Server (NTRS)

Aleman, Alicia; Olsen, Lola; Ritz, Scott; Morahan, Michael; Cepero, Laurel; Stevens, Tyler

2011-01-01

NASA's Global Change Master Directory provides the scientific community with the ability to discover, access, and use Earth science data, data-related services, and climate diagnostics worldwide. The GCMD offers descriptions of Earth science data sets using the Directory Interchange Format (DIF) metadata standard; Earth science related data services are described using the Service Entry Resource Format (SERF); and climate visualizations are described using the Climate Diagnostic (CD) standard. The DIF, SERF and CD standards each capture data attributes used to determine whether a data set, service, or climate visualization is relevant to a user's needs. Metadata fields include: title, summary, science keywords, service keywords, data center, data set citation, personnel, instrument, platform, quality, related URL, temporal and spatial coverage, data resolution and distribution information. In addition, nine valuable sets of controlled vocabularies have been developed to assist users in normalizing the search for data descriptions. An update to the GCMD's search functionality is planned to further capitalize on the controlled vocabularies during database queries. By implementing a dynamic keyword "tree", users will have the ability to search for data sets by combining keywords in new ways. This will allow users to conduct more relevant and efficient database searches to support the free exchange and re-use of Earth science data. http://gcmd.nasa.gov/

Interoperable web applications for sharing data and products of the International DORIS Service

NASA Astrophysics Data System (ADS)

Soudarin, L.; Ferrage, P.

2017-12-01

The International DORIS Service (IDS) was created in 2003 under the umbrella of the International Association of Geodesy (IAG) to foster scientific research related to the French satellite tracking system DORIS and to deliver scientific products, mostly related to the International Earth rotation and Reference systems Service (IERS). Since its start, the organization has continuously evolved, leading to additional and improved operational products from an expanded set of DORIS Analysis Centers. In addition, IDS has developed services for sharing data and products with the users. Metadata and interoperable web applications are proposed to explore, visualize and download the key products such as the position time series of the geodetic points materialized at the ground tracking stations. The Global Geodetic Observing System (GGOS) encourages the IAG Services to develop such interoperable facilities on their website. The objective for GGOS is to set up an interoperable portal through which the data and products produced by the IAG Services can be served to the user community. We present the web applications proposed by IDS to visualize time series of geodetic observables or to get information about the tracking ground stations and the tracked satellites. We discuss the future plans for IDS to meet the recommendations of GGOS. The presentation also addresses the needs for the IAG Services to adopt common metadata thesaurus to describe data and products, and interoperability standards to share them.

A Window to the World: Lessons Learned from NASA's Collaborative Metadata Curation Effort

NASA Astrophysics Data System (ADS)

Bugbee, K.; Dixon, V.; Baynes, K.; Shum, D.; le Roux, J.; Ramachandran, R.

2017-12-01

Well written descriptive metadata adds value to data by making data easier to discover as well as increases the use of data by providing the context or appropriateness of use. While many data centers acknowledge the importance of correct, consistent and complete metadata, allocating resources to curate existing metadata is often difficult. To lower resource costs, many data centers seek guidance on best practices for curating metadata but struggle to identify those recommendations. In order to assist data centers in curating metadata and to also develop best practices for creating and maintaining metadata, NASA has formed a collaborative effort to improve the Earth Observing System Data and Information System (EOSDIS) metadata in the Common Metadata Repository (CMR). This effort has taken significant steps in building consensus around metadata curation best practices. However, this effort has also revealed gaps in EOSDIS enterprise policies and procedures within the core metadata curation task. This presentation will explore the mechanisms used for building consensus on metadata curation, the gaps identified in policies and procedures, the lessons learned from collaborating with both the data centers and metadata curation teams, and the proposed next steps for the future.

Ubiquitous UAVs: a cloud based framework for storing, accessing and processing huge amount of video footage in an efficient way

NASA Astrophysics Data System (ADS)

Efstathiou, Nectarios; Skitsas, Michael; Psaroudakis, Chrysostomos; Koutras, Nikolaos

2017-09-01

Nowadays, video surveillance cameras are used for the protection and monitoring of a huge number of facilities worldwide. An important element in such surveillance systems is the use of aerial video streams originating from onboard sensors located on Unmanned Aerial Vehicles (UAVs). Video surveillance using UAVs represent a vast amount of video to be transmitted, stored, analyzed and visualized in a real-time way. As a result, the introduction and development of systems able to handle huge amount of data become a necessity. In this paper, a new approach for the collection, transmission and storage of aerial videos and metadata is introduced. The objective of this work is twofold. First, the integration of the appropriate equipment in order to capture and transmit real-time video including metadata (i.e. position coordinates, target) from the UAV to the ground and, second, the utilization of the ADITESS Versatile Media Content Management System (VMCMS-GE) for storing of the video stream and the appropriate metadata. Beyond the storage, VMCMS-GE provides other efficient management capabilities such as searching and processing of videos, along with video transcoding. For the evaluation and demonstration of the proposed framework we execute a use case where the surveillance of critical infrastructure and the detection of suspicious activities is performed. Collected video Transcodingis subject of this evaluation as well.

Atherosclerosis and Stroke

MedlinePlus

... Stroke and atherosclerosis There are two types of ischemic stroke caused by blood clots, narrowing of blood vessels ... 2 What Is an Arteriovenous Malformation (AVM)? 3 Ischemic Strokes (Clots) 4 Hemorrhagic Strokes (Bleeds) 5 What You ...

Evaluating and Evolving Metadata in Multiple Dialects

NASA Astrophysics Data System (ADS)

Kozimor, J.; Habermann, T.; Powers, L. A.; Gordon, S.

2016-12-01

Despite many long-term homogenization efforts, communities continue to develop focused metadata standards along with related recommendations and (typically) XML representations (aka dialects) for sharing metadata content. Different representations easily become obstacles to sharing information because each representation generally requires a set of tools and skills that are designed, built, and maintained specifically for that representation. In contrast, community recommendations are generally described, at least initially, at a more conceptual level and are more easily shared. For example, most communities agree that dataset titles should be included in metadata records although they write the titles in different ways. This situation has led to the development of metadata repositories that can ingest and output metadata in multiple dialects. As an operational example, the NASA Common Metadata Repository (CMR) includes three different metadata dialects (DIF, ECHO, and ISO 19115-2). These systems raise a new question for metadata providers: if I have a choice of metadata dialects, which should I use and how do I make that decision? We have developed a collection of metadata evaluation tools that can be used to evaluate metadata records in many dialects for completeness with respect to recommendations from many organizations and communities. We have applied these tools to over 8000 collection and granule metadata records in four different dialects. This large collection of identical content in multiple dialects enables us to address questions about metadata and dialect evolution and to answer those questions quantitatively. We will describe those tools and results from evaluating the NASA CMR metadata collection.

Integration of upper air data in the MeteoSwiss Data Warehouse

NASA Astrophysics Data System (ADS)

Musa, M.; Haeberli, Ch.; Ruffieux, D.

2010-09-01

Over the last 10 years MeteoSwiss established a Data Warehouse in order to get one single, integrated data platform for all kinds of meteorological and climatological data. In the MeteoSwiss Data Warehouse data and metadata are hold in a metadata driven relational database. To reach this goal, we started with the integration of the actual and historical data from our surface stations in a first step, including routines for aggregation and calculation and the implementation of enhanced Quality Control tools. In 2008 we started with the integration of actual and historical upper air data like soundings (PTU, Wind and Ozone), any kind of profilers like wind profiler or radiometer, profiles calculated from numerical weather models and AMDAR data in the Data Warehouse. The dataset includes also high resolution sounding data from the station Payerne and TEMP data from 20 European stations since 1942. A critical point was to work out a concept for the general architecture which could deal with all different types of data. While integrating the data itself all metadata of the aerological station Payerne was transferred and imported in the central metadata repository of the Data Warehouse. The implementation of the real time and daily QC tools as well as the routines for aggregation and calculation were realized in an analog way as for the surface data. The Quality Control tools include plausibility tests like limit tests, consistency tests in the same level and vertical consistency tests. From the beginning it was the aim to support the MeteoSwiss integration strategy which deals with all aspects of integration like various observing technologies and platforms, observing systems outside MeteoSwiss and the data and metadata itself. This kind of integration comprises all aspects of "Enterprise Data Integration". After the integration, the historical as well as the actual upper air data are now available for the climatologists and meteorologists with standardized access for data retrieving and visualization. We are convinced making these data accessible for the scientist is a good contribution to a better understanding of high resolution climatology.

Sally Ride EarthKAM - Automated Image Geo-Referencing Using Google Earth Web Plug-In

NASA Technical Reports Server (NTRS)

Andres, Paul M.; Lazar, Dennis K.; Thames, Robert Q.

2013-01-01

Sally Ride EarthKAM is an educational program funded by NASA that aims to provide the public the ability to picture Earth from the perspective of the International Space Station (ISS). A computer-controlled camera is mounted on the ISS in a nadir-pointing window; however, timing limitations in the system cause inaccurate positional metadata. Manually correcting images within an orbit allows the positional metadata to be improved using mathematical regressions. The manual correction process is time-consuming and thus, unfeasible for a large number of images. The standard Google Earth program allows for the importing of KML (keyhole markup language) files that previously were created. These KML file-based overlays could then be manually manipulated as image overlays, saved, and then uploaded to the project server where they are parsed and the metadata in the database is updated. The new interface eliminates the need to save, download, open, re-save, and upload the KML files. Everything is processed on the Web, and all manipulations go directly into the database. Administrators also have the control to discard any single correction that was made and validate a correction. This program streamlines a process that previously required several critical steps and was probably too complex for the average user to complete successfully. The new process is theoretically simple enough for members of the public to make use of and contribute to the success of the Sally Ride EarthKAM project. Using the Google Earth Web plug-in, EarthKAM images, and associated metadata, this software allows users to interactively manipulate an EarthKAM image overlay, and update and improve the associated metadata. The Web interface uses the Google Earth JavaScript API along with PHP-PostgreSQL to present the user the same interface capabilities without leaving the Web. The simpler graphical user interface will allow the public to participate directly and meaningfully with EarthKAM. The use of similar techniques is being investigated to place ground-based observations in a Google Mars environment, allowing the MSL (Mars Science Laboratory) Science Team a means to visualize the rover and its environment.

Data to Pictures to Data: Outreach Imaging Software and Metadata

NASA Astrophysics Data System (ADS)

Levay, Z.

2011-07-01

A convergence between astronomy science and digital photography has enabled a steady stream of visually rich imagery from state-of-the-art data. The accessibility of hardware and software has facilitated an explosion of astronomical images for outreach, from space-based observatories, ground-based professional facilities and among the vibrant amateur astrophotography community. Producing imagery from science data involves a combination of custom software to understand FITS data (FITS Liberator), off-the-shelf, industry-standard software to composite multi-wavelength data and edit digital photographs (Adobe Photoshop), and application of photo/image-processing techniques. Some additional effort is needed to close the loop and enable this imagery to be conveniently available for various purposes beyond web and print publication. The metadata paradigms in digital photography are now complying with FITS and science software to carry information such as keyword tags and world coordinates, enabling these images to be usable in more sophisticated, imaginative ways exemplified by Sky in Google Earth and World Wide Telescope.

Concept indexing and expansion for social multimedia websites based on semantic processing and graph analysis

NASA Astrophysics Data System (ADS)

Lin, Po-Chuan; Chen, Bo-Wei; Chang, Hangbae

2016-07-01

This study presents a human-centric technique for social video expansion based on semantic processing and graph analysis. The objective is to increase metadata of an online video and to explore related information, thereby facilitating user browsing activities. To analyze the semantic meaning of a video, shots and scenes are firstly extracted from the video on the server side. Subsequently, this study uses annotations along with ConceptNet to establish the underlying framework. Detailed metadata, including visual objects and audio events among the predefined categories, are indexed by using the proposed method. Furthermore, relevant online media associated with each category are also analyzed to enrich the existing content. With the above-mentioned information, users can easily browse and search the content according to the link analysis and its complementary knowledge. Experiments on a video dataset are conducted for evaluation. The results show that our system can achieve satisfactory performance, thereby demonstrating the feasibility of the proposed idea.

Exploring neighborhoods in the metagenome universe.

PubMed

Aßhauer, Kathrin P; Klingenberg, Heiner; Lingner, Thomas; Meinicke, Peter

2014-07-14

The variety of metagenomes in current databases provides a rapidly growing source of information for comparative studies. However, the quantity and quality of supplementary metadata is still lagging behind. It is therefore important to be able to identify related metagenomes by means of the available sequence data alone. We have studied efficient sequence-based methods for large-scale identification of similar metagenomes within a database retrieval context. In a broad comparison of different profiling methods we found that vector-based distance measures are well-suitable for the detection of metagenomic neighbors. Our evaluation on more than 1700 publicly available metagenomes indicates that for a query metagenome from a particular habitat on average nine out of ten nearest neighbors represent the same habitat category independent of the utilized profiling method or distance measure. While for well-defined labels a neighborhood accuracy of 100% can be achieved, in general the neighbor detection is severely affected by a natural overlap of manually annotated categories. In addition, we present results of a novel visualization method that is able to reflect the similarity of metagenomes in a 2D scatter plot. The visualization method shows a similarly high accuracy in the reduced space as compared with the high-dimensional profile space. Our study suggests that for inspection of metagenome neighborhoods the profiling methods and distance measures can be chosen to provide a convenient interpretation of results in terms of the underlying features. Furthermore, supplementary metadata of metagenome samples in the future needs to comply with readily available ontologies for fine-grained and standardized annotation. To make profile-based k-nearest-neighbor search and the 2D-visualization of the metagenome universe available to the research community, we included the proposed methods in our CoMet-Universe server for comparative metagenome analysis.

Exploring Neighborhoods in the Metagenome Universe

PubMed Central

Aßhauer, Kathrin P.; Klingenberg, Heiner; Lingner, Thomas; Meinicke, Peter

2014-01-01

The variety of metagenomes in current databases provides a rapidly growing source of information for comparative studies. However, the quantity and quality of supplementary metadata is still lagging behind. It is therefore important to be able to identify related metagenomes by means of the available sequence data alone. We have studied efficient sequence-based methods for large-scale identification of similar metagenomes within a database retrieval context. In a broad comparison of different profiling methods we found that vector-based distance measures are well-suitable for the detection of metagenomic neighbors. Our evaluation on more than 1700 publicly available metagenomes indicates that for a query metagenome from a particular habitat on average nine out of ten nearest neighbors represent the same habitat category independent of the utilized profiling method or distance measure. While for well-defined labels a neighborhood accuracy of 100% can be achieved, in general the neighbor detection is severely affected by a natural overlap of manually annotated categories. In addition, we present results of a novel visualization method that is able to reflect the similarity of metagenomes in a 2D scatter plot. The visualization method shows a similarly high accuracy in the reduced space as compared with the high-dimensional profile space. Our study suggests that for inspection of metagenome neighborhoods the profiling methods and distance measures can be chosen to provide a convenient interpretation of results in terms of the underlying features. Furthermore, supplementary metadata of metagenome samples in the future needs to comply with readily available ontologies for fine-grained and standardized annotation. To make profile-based k-nearest-neighbor search and the 2D-visualization of the metagenome universe available to the research community, we included the proposed methods in our CoMet-Universe server for comparative metagenome analysis. PMID:25026170

Earth Science Datacasting v2.0

NASA Technical Reports Server (NTRS)

Bingham, Andrew W.; Deen, Robert G.; Hussey, Kevin J.; Stough, Timothy M.; McCleese, Sean W.; Toole, Nicholas T.

2012-01-01

The Datacasting software, which consists of a server and a client, has been developed as part of the Earth Science (ES) Datacasting project. The goal of ES Datacasting is to provide scientists the ability to automatically and continuously download Earth science data that meets a precise, predefined need, and then to instantaneously visualize it on a local computer. This is achieved by applying the concept of podcasting to deliver science data over the Internet using RSS (Really Simple Syndication) XML feeds. By extending the RSS specification, scientists can filter a feed and only download the files that are required for a particular application (for example, only files that contain information about a particular event, such as a hurricane or flood). The extension also provides the ability for the client to understand the format of the data and visualize the information locally. The server part enables a data provider to create and serve basic Datacasting (RSS-based) feeds. The user can subscribe to any number of feeds, view the information related to each item contained within a feed (including browse pre-made images), manually download files associated with items, and place these files in a local store. The client-server architecture enables users to: a) Subscribe and interpret multiple Datacasting feeds (same look and feel as a typical mail client), b) Maintain a list of all items within each feed, c) Enable filtering on the lists based on different metadata attributes contained within the feed (list will reference only data files of interest), d) Visualize the reference data and associated metadata, e) Download files referenced within the list, and f) Automatically download files as new items become available.

MyGeoHub: A Collaborative Geospatial Research and Education Platform

NASA Astrophysics Data System (ADS)

Kalyanam, R.; Zhao, L.; Biehl, L. L.; Song, C. X.; Merwade, V.; Villoria, N.

2017-12-01

Scientific research is increasingly collaborative and globally distributed; research groups now rely on web-based scientific tools and data management systems to simplify their day-to-day collaborative workflows. However, such tools often lack seamless interfaces, requiring researchers to contend with manual data transfers, annotation and sharing. MyGeoHub is a web platform that supports out-of-the-box, seamless workflows involving data ingestion, metadata extraction, analysis, sharing and publication. MyGeoHub is built on the HUBzero cyberinfrastructure platform and adds general-purpose software building blocks (GABBs), for geospatial data management, visualization and analysis. A data management building block iData, processes geospatial files, extracting metadata for keyword and map-based search while enabling quick previews. iData is pervasive, allowing access through a web interface, scientific tools on MyGeoHub or even mobile field devices via a data service API. GABBs includes a Python map library as well as map widgets that in a few lines of code, generate complete geospatial visualization web interfaces for scientific tools. GABBs also includes powerful tools that can be used with no programming effort. The GeoBuilder tool provides an intuitive wizard for importing multi-variable, geo-located time series data (typical of sensor readings, GPS trackers) to build visualizations supporting data filtering and plotting. MyGeoHub has been used in tutorials at scientific conferences and educational activities for K-12 students. MyGeoHub is also constantly evolving; the recent addition of Jupyter and R Shiny notebook environments enable reproducible, richly interactive geospatial analyses and applications ranging from simple pre-processing to published tools. MyGeoHub is not a monolithic geospatial science gateway, instead it supports diverse needs ranging from just a feature-rich data management system, to complex scientific tools and workflows.

SATORI: a system for ontology-guided visual exploration of biomedical data repositories.

PubMed

Lekschas, Fritz; Gehlenborg, Nils

2018-04-01

The ever-increasing number of biomedical datasets provides tremendous opportunities for re-use but current data repositories provide limited means of exploration apart from text-based search. Ontological metadata annotations provide context by semantically relating datasets. Visualizing this rich network of relationships can improve the explorability of large data repositories and help researchers find datasets of interest. We developed SATORI-an integrative search and visual exploration interface for the exploration of biomedical data repositories. The design is informed by a requirements analysis through a series of semi-structured interviews. We evaluated the implementation of SATORI in a field study on a real-world data collection. SATORI enables researchers to seamlessly search, browse and semantically query data repositories via two visualizations that are highly interconnected with a powerful search interface. SATORI is an open-source web application, which is freely available at http://satori.refinery-platform.org and integrated into the Refinery Platform. nils@hms.harvard.edu. Supplementary data are available at Bioinformatics online.

Generic interpreters and microprocessor verification

NASA Technical Reports Server (NTRS)

Windley, Phillip J.

1990-01-01

The following topics are covered in viewgraph form: (1) generic interpreters; (2) Viper microprocessors; (3) microprocessor verification; (4) determining correctness; (5) hierarchical decomposition; (6) interpreter theory; (7) AVM-1; (8) phase-level specification; and future work.

What Is an Arteriovenous Malformation (AVM)?

MedlinePlus

... sensory information, such as interpretation of pain and temperature, light touch, vibration and more. The temporal lobe functions to process things related to hearing, memory, learning and receptive speech. The occipital lobe functions to ...

Vibration Tests on Transit Buses

DOT National Transportation Integrated Search

1979-03-01

The objective of this vibration measurement program was to quantify the vibration environment which would be experienced by Automatic Vehicle Monitoring (AVM) equipment when installed on buses during typical city route service operations. Two buses w...

Acquired uterine arteriovenous malformation developing in retained products of conception: a diagnostic dilemma.

PubMed

Goyal, Surbhi; Goyal, Ankur; Mahajan, Surbhi; Sharma, Shikha; Dev, Geeta

2014-01-01

Abnormal uterine bleeding in the postabortal period requires meticulous diagnostic work-up to decide proper management. Imaging modalities including Doppler sonography and magnetic resonance imaging in concert with clinical and laboratory findings are useful to narrow the differential diagnoses but are not definitive. Presence of increased uterine vascularity and arteriovenous shunting is non-specific and can be detected in a variety of conditions including retained trophoblastic tissue, gestational trophoblastic disease, arteriovenous malformation (AVM), placental polyp and vascular neoplasm. We present here a case of a multiparous woman with unexplained postabortal bleeding posing a diagnostic challenge. Excluding the possibility of AVM before attempting dilatation and curettage in such a clinical scenario is crucial to prevent catastrophic bleeding. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

EOS ODL Metadata On-line Viewer

NASA Astrophysics Data System (ADS)

Yang, J.; Rabi, M.; Bane, B.; Ullman, R.

2002-12-01

We have recently developed and deployed an EOS ODL metadata on-line viewer. The EOS ODL metadata viewer is a web server that takes: 1) an EOS metadata file in Object Description Language (ODL), 2) parameters, such as which metadata to view and what style of display to use, and returns an HTML or XML document displaying the requested metadata in the requested style. This tool is developed to address widespread complaints by science community that the EOS Data and Information System (EOSDIS) metadata files in ODL are difficult to read by allowing users to upload and view an ODL metadata file in different styles using a web browser. Users have the selection to view all the metadata or part of the metadata, such as Collection metadata, Granule metadata, or Unsupported Metadata. Choices of display styles include 1) Web: a mouseable display with tabs and turn-down menus, 2) Outline: Formatted and colored text, suitable for printing, 3) Generic: Simple indented text, a direct representation of the underlying ODL metadata, and 4) None: No stylesheet is applied and the XML generated by the converter is returned directly. Not all display styles are implemented for all the metadata choices. For example, Web style is only implemented for Collection and Granule metadata groups with known attribute fields, but not for Unsupported, Other, and All metadata. The overall strategy of the ODL viewer is to transform an ODL metadata file to a viewable HTML in two steps. The first step is to convert the ODL metadata file to an XML using a Java-based parser/translator called ODL2XML. The second step is to transform the XML to an HTML using stylesheets. Both operations are done on the server side. This allows a lot of flexibility in the final result, and is very portable cross-platform. Perl CGI behind the Apache web server is used to run the Java ODL2XML, and then run the results through an XSLT processor. The EOS ODL viewer can be accessed from either a PC or a Mac using Internet Explorer 5.0+ or Netscape 4.7+.

ISO 19115 Experiences in NASA's Earth Observing System (EOS) ClearingHOuse (ECHO)

NASA Astrophysics Data System (ADS)

Cechini, M. F.; Mitchell, A.

2011-12-01

Metadata is an important entity in the process of cataloging, discovering, and describing earth science data. As science research and the gathered data increases in complexity, so does the complexity and importance of descriptive metadata. To meet these growing needs, the metadata models required utilize richer and more mature metadata attributes. Categorizing, standardizing, and promulgating these metadata models to a politically, geographically, and scientifically diverse community is a difficult process. An integral component of metadata management within NASA's Earth Observing System Data and Information System (EOSDIS) is the Earth Observing System (EOS) ClearingHOuse (ECHO). ECHO is the core metadata repository for the EOSDIS data centers providing a centralized mechanism for metadata and data discovery and retrieval. ECHO has undertaken an internal restructuring to meet the changing needs of scientists, the consistent advancement in technology, and the advent of new standards such as ISO 19115. These improvements were based on the following tenets for data discovery and retrieval: + There exists a set of 'core' metadata fields recommended for data discovery. + There exists a set of users who will require the entire metadata record for advanced analysis. + There exists a set of users who will require a 'core' set metadata fields for discovery only. + There will never be a cessation of new formats or a total retirement of all old formats. + Users should be presented metadata in a consistent format of their choosing. In order to address the previously listed items, ECHO's new metadata processing paradigm utilizes the following approach: + Identify a cross-format set of 'core' metadata fields necessary for discovery. + Implement format-specific indexers to extract the 'core' metadata fields into an optimized query capability. + Archive the original metadata in its entirety for presentation to users requiring the full record. + Provide on-demand translation of 'core' metadata to any supported result format. Lessons learned by the ECHO team while implementing its new metadata approach to support usage of the ISO 19115 standard will be presented. These lessons learned highlight some discovered strengths and weaknesses in the ISO 19115 standard as it is introduced to an existing metadata processing system.

Accuracy of acoustic velocity metering systems for measurement of low velocity in open channels

USGS Publications Warehouse

Laenen, Antonius; Curtis, R. E.

1989-01-01

Acoustic velocity meter (AVM) accuracy depends on equipment limitations, the accuracy of acoustic-path length and angle determination, and the stability of the mean velocity to acoustic-path velocity relation. Equipment limitations depend on path length and angle, transducer frequency, timing oscillator frequency, and signal-detection scheme. Typically, the velocity error from this source is about +or-1 to +or-10 mms/sec. Error in acoustic-path angle or length will result in a proportional measurement bias. Typically, an angle error of one degree will result in a velocity error of 2%, and a path-length error of one meter in 100 meter will result in an error of 1%. Ray bending (signal refraction) depends on path length and density gradients present in the stream. Any deviation from a straight acoustic path between transducer will change the unique relation between path velocity and mean velocity. These deviations will then introduce error in the mean velocity computation. Typically, for a 200-meter path length, the resultant error is less than one percent, but for a 1,000 meter path length, the error can be greater than 10%. Recent laboratory and field tests have substantiated assumptions of equipment limitations. Tow-tank tests of an AVM system with a 4.69-meter path length yielded an average standard deviation error of 9.3 mms/sec, and the field tests of an AVM system with a 20.5-meter path length yielded an average standard deviation error of a 4 mms/sec. (USGS)

Design of poly(acrylonitrile)-based gel electrolytes for high-performance lithium ion batteries.

PubMed

Wang, Shih-Hong; Kuo, Ping-Lin; Hsieh, Chien-Te; Teng, Hsisheng

2014-11-12

The use of polyacrylonitrile (PAN) as a host for gel polymer electrolytes (GPEs) commonly produces a strong dipole-dipole interaction with the polymer. This study presents a strategy for the application of PAN in GPEs for the production of high performance lithium ion batteries. The resulting gel electrolyte GPE-AVM comprises a poly(acrylonitrile-co-vinyl acetate) copolymer blending poly(methyl methacrylate) as a host, which is swelled using a liquid electrolyte (LE) of 1 M LiPF6 in carbonate solvent. Vinyl acetate and methacrylate groups segregate the PAN chains in the GPE, which produces high ionic conductivity (3.5 × 10 (-3) S cm(-1) at 30 °C) and a wide electrochemical voltage range (>6.5 V) as well as an excellent Li(+) transference number of 0.6. This study includes GPE-AVM in a full-cell battery comprising a LiFePO4 cathode and graphite anode to promote ion motion, which reduced resistance in the battery by 39% and increased the specific power by 110%, relative to the performance of batteries based on LE. The proposed GPE-based battery has a capacity of 140 mAh g(-1) at a discharge rate of 0.1 C and is able to deliver 67 mAh g(-1) of electricity at 17 C. The proposed GPE-AVM provides a robust interface with the electrodes in full-cell batteries, resulting in 93% capacity retention after 100 charge-discharge cycles at 17 C and 63% retention after 1000 cycles.

Adaptive on-line calibration for around-view monitoring system using between-camera homography estimation

NASA Astrophysics Data System (ADS)

Lim, Sungsoo; Lee, Seohyung; Kim, Jun-geon; Lee, Daeho

2018-01-01

The around-view monitoring (AVM) system is one of the major applications of advanced driver assistance systems and intelligent transportation systems. We propose an on-line calibration method, which can compensate misalignments for AVM systems. Most AVM systems use fisheye undistortion, inverse perspective transformation, and geometrical registration methods. To perform these procedures, the parameters for each process must be known; the procedure by which the parameters are estimated is referred to as the initial calibration. However, when only using the initial calibration data, we cannot compensate misalignments, caused by changing equilibria of cars. Moreover, even small changes such as tire pressure levels, passenger weight, or road conditions can affect a car's equilibrium. Therefore, to compensate for this misalignment, additional techniques are necessary, specifically an on-line calibration method. On-line calibration can recalculate homographies, which can correct any degree of misalignment using the unique features of ordinary parking lanes. To extract features from the parking lanes, this method uses corner detection and a pattern matching algorithm. From the extracted features, homographies are estimated using random sample consensus and parameter estimation. Finally, the misaligned epipolar geographies are compensated via the estimated homographies. Thus, the proposed method can render image planes parallel to the ground. This method does not require any designated patterns and can be used whenever cars are placed in a parking lot. The experimental results show the robustness and efficiency of the method.

Recording, Visualization and Documentation of 3D Spatial Data for Monitoring Topography in Areas of Cultural Heritage

NASA Astrophysics Data System (ADS)

Maravelakis, Emmanouel; Konstantaras, Antonios; Axaridou, Anastasia; Chrysakis, Ioannis; Xinogalos, Michalis

2014-05-01

This research investigates the application of new system for 3D documentation of land degradation and its effect [1,2] on areas of cultural heritage via complete 3D data acquisition, 3D modeling and metadata recording using terrestrial laser scanners (TLS) [3,4,5]. As land degradation progresses through time it is important to be able to map and exactly replicate with great precision the entire 3D shape of the physical objects of interest, such as landslides, ground erosion, river boundaries, mad accumulation, etc. [1,2] TLS enables the extraction and recording of a very large number of points in space with great precision and without the need for any physical contact with the object of interest. Field specialists can then examine the produced models and comment on them both on the overall object of interest and on specific features of it by inserting annotations on certain parts of the model [6]. This process could be proven to be very cost effective as it can be repeated as often as necessary and produce a well catalogued documentation of the progress of land degradation at particular areas. The problem with repeating TLS models lies on the various types of hardware equipment and software systems that might be used for the extraction of point clouds, and the different people that might be called to analyze the findings. These often result in a large volume of interim and final products with little if no standardization, multiple different metadata and vague documentation [7], which makes metadata recordings [8] crucial both for one scientist to be able to follow upon the work of the other as well as being able to repeat the same work when deemed necessary. This makes the need for a repository tool proposed by the authors essential in order to record all work that is done in every TLS scanning, and makes the technology accessible to scientists of various different fields [9,10], eg. geologists, physicists, topographers, remote sensing engineers, archaeologists etc. allowing them to interchange their knowledge, findings and observations at different time frames. Results outline the successful application of the above systems in certain Greek areas of important cultural heritage [3,11] were significant efforts are being made for their preservation through time. Acknowledgement The authors wish to thank the General Secretariat for Research and Technology of Ministry of Education and Religious Affairs, Culture and Sports in Greece for their financial support via program Cooperation: Partnership of Production and Research Institutions in Small and Medium Scale Projects, Project Title: "3D-SYSTEK - Development of a novel system for 3D Documentation, Promotion and Exploitation of Cultural Heritage Monuments via 3D data acquisition, 3D modeling and metadata recording". Keywords spatial data, land degradation monitoring, 3D modeling and visualization, terrestrial laser scanning, documentation and metadata repository, protection of cultural heritage References [1] Shalaby, A., and Tateishi, R.: Remote sensing and GIS for mapping and monitoring land cover and land-use changes in the northwestern coastal zone of egypt. Applied Geography, 27(1), 28-41, (2007) [2] Poesen, J. W. A., and Hooke, J. M.: Erosion, flooding and channel management in mediterranean environments of southern europe. Progress in Physical Geography, 21(2), 157-199, (1997) [3] Maravelakis, E., Bilalis, N., Mantzorou, I., Konstantaras, A., Antoniadis, A.: 3D modeling of the oldest olive tree of the world. IJCER 2(2), 340-347 (2012) [4] Manferdini, A.M., Remondino, F.: Reality-Based 3D Modeling, Segmentation and Web- Based Visualization. In: Ioannides, M., Fellner, D., Georgopoulos, A., Hadjimitsis, D.G. (eds.) EuroMed 2010. LNCS, vol. 6436, pp. 110-124. Springer, Heidelberg (2010) [5] Tapete, D., Casagli, N., Luzi, G., Fanti, R., Gigli, G., Leva, D.: Integrating radar and laserbased remote sensing techniques for monitoring structural deformation of archaeological monuments. Journal of Archaeological Science 40, 176-189 (2012) [6] Sinclair, P., Addis, M., Choi, F., Doerr, M., Lewis, P., Martinez, K.: The Use of CRM Core in Multimedia Annotation. In: First International Workshop on Semantic Web Annotations for Multimedia (2006) [7] Zhiming, Z., et al.: Scientific workflow management: between generality and applicability. In: Proc. the 5th International Conference on Quality Software, Melbourne, Australia, pp. 19-20 (2005) [8] Infrastructure for Spatial Information in Europe. INSPIRE Architecture and Standards Position Paper (2002) [9] Doerr, M., Kritsotaki, A.: Documenting events in metadata. In: The e-volution of Information Communication Technology in Cultural Heritage, pp. 56-61 (2006) [10] Maravelakis, E., Konstantaras, A., Kritsotaki, A., Angelakis, D. and Xinogalos, M.: Analysing User Needs for a Unified 3D Metadata Recording and Exploitation of Cultural Heritage Monuments System, Advances in Visual Computing, Lecture Notes in Computer Science Volume 8034, pp 138-147, (2013) [11] Maravelakis, E., Andrianakis, M., Psarakis, K., Bolanakis, N., Tzatzanis, G., Bilalis, N., Antoniadis, A.: Lessons Learned from Cultural Heritage Digitisation Projects in Crete. In: Proceedings of the 14th International Conference on Virtual Systems and Multimedia, pp. 152-156 (2008)

Creating context for the experiment record. User-defined metadata: investigations into metadata usage in the LabTrove ELN.

PubMed

Willoughby, Cerys; Bird, Colin L; Coles, Simon J; Frey, Jeremy G

2014-12-22

The drive toward more transparency in research, the growing willingness to make data openly available, and the reuse of data to maximize the return on research investment all increase the importance of being able to find information and make links to the underlying data. The use of metadata in Electronic Laboratory Notebooks (ELNs) to curate experiment data is an essential ingredient for facilitating discovery. The University of Southampton has developed a Web browser-based ELN that enables users to add their own metadata to notebook entries. A survey of these notebooks was completed to assess user behavior and patterns of metadata usage within ELNs, while user perceptions and expectations were gathered through interviews and user-testing activities within the community. The findings indicate that while some groups are comfortable with metadata and are able to design a metadata structure that works effectively, many users are making little attempts to use it, thereby endangering their ability to recover data in the future. A survey of patterns of metadata use in these notebooks, together with feedback from the user community, indicated that while a few groups are comfortable with metadata and are able to design a metadata structure that works effectively, many users adopt a "minimum required" approach to metadata. To investigate whether the patterns of metadata use in LabTrove were unusual, a series of surveys were undertaken to investigate metadata usage in a variety of platforms supporting user-defined metadata. These surveys also provided the opportunity to investigate whether interface designs in these other environments might inform strategies for encouraging metadata creation and more effective use of metadata in LabTrove.

ASDC Collaborations and Processes to Ensure Quality Metadata and Consistent Data Availability

NASA Astrophysics Data System (ADS)

Trapasso, T. J.

2017-12-01

With the introduction of new tools, faster computing, and less expensive storage, increased volumes of data are expected to be managed with existing or fewer resources. Metadata management is becoming a heightened challenge from the increase in data volume, resulting in more metadata records needed to be curated for each product. To address metadata availability and completeness, NASA ESDIS has taken significant strides with the creation of the United Metadata Model (UMM) and Common Metadata Repository (CMR). These UMM helps address hurdles experienced by the increasing number of metadata dialects and the CMR provides a primary repository for metadata so that required metadata fields can be served through a growing number of tools and services. However, metadata quality remains an issue as metadata is not always inherent to the end-user. In response to these challenges, the NASA Atmospheric Science Data Center (ASDC) created the Collaboratory for quAlity Metadata Preservation (CAMP) and defined the Product Lifecycle Process (PLP) to work congruently. CAMP is unique in that it provides science team members a UI to directly supply metadata that is complete, compliant, and accurate for their data products. This replaces back-and-forth communication that often results in misinterpreted metadata. Upon review by ASDC staff, metadata is submitted to CMR for broader distribution through Earthdata. Further, approval of science team metadata in CAMP automatically triggers the ASDC PLP workflow to ensure appropriate services are applied throughout the product lifecycle. This presentation will review the design elements of CAMP and PLP as well as demonstrate interfaces to each. It will show the benefits that CAMP and PLP provide to the ASDC that could potentially benefit additional NASA Earth Science Data and Information System (ESDIS) Distributed Active Archive Centers (DAACs).

Metadata squared: enhancing its usability for volunteered geographic information and the GeoWeb

USGS Publications Warehouse

Poore, Barbara S.; Wolf, Eric B.; Sui, Daniel Z.; Elwood, Sarah; Goodchild, Michael F.

2013-01-01

The Internet has brought many changes to the way geographic information is created and shared. One aspect that has not changed is metadata. Static spatial data quality descriptions were standardized in the mid-1990s and cannot accommodate the current climate of data creation where nonexperts are using mobile phones and other location-based devices on a continuous basis to contribute data to Internet mapping platforms. The usability of standard geospatial metadata is being questioned by academics and neogeographers alike. This chapter analyzes current discussions of metadata to demonstrate how the media shift that is occurring has affected requirements for metadata. Two case studies of metadata use are presented—online sharing of environmental information through a regional spatial data infrastructure in the early 2000s, and new types of metadata that are being used today in OpenStreetMap, a map of the world created entirely by volunteers. Changes in metadata requirements are examined for usability, the ease with which metadata supports coproduction of data by communities of users, how metadata enhances findability, and how the relationship between metadata and data has changed. We argue that traditional metadata associated with spatial data infrastructures is inadequate and suggest several research avenues to make this type of metadata more interactive and effective in the GeoWeb.

Evolutions in Metadata Quality

NASA Astrophysics Data System (ADS)

Gilman, J.

2016-12-01

Metadata Quality is one of the chief drivers of discovery and use of NASA EOSDIS (Earth Observing System Data and Information System) data. Issues with metadata such as lack of completeness, inconsistency, and use of legacy terms directly hinder data use. As the central metadata repository for NASA Earth Science data, the Common Metadata Repository (CMR) has a responsibility to its users to ensure the quality of CMR search results. This talk will cover how we encourage metadata authors to improve the metadata through the use of integrated rubrics of metadata quality and outreach efforts. In addition we'll demonstrate Humanizers, a technique for dealing with the symptoms of metadata issues. Humanizers allow CMR administrators to identify specific metadata issues that are fixed at runtime when the data is indexed. An example Humanizer is the aliasing of processing level "Level 1" to "1" to improve consistency across collections. The CMR currently indexes 35K collections and 300M granules.

Data Fusion and Visualization with the OpenEarth Framework (OEF)

NASA Astrophysics Data System (ADS)

Nadeau, D. R.; Baru, C.; Fouch, M. J.; Crosby, C. J.

2010-12-01

Data fusion is an increasingly important problem to solve as we strive to integrate data from multiple sources and build better models of the complex processes operating at the Earth’s surface and its interior. These data are often large, multi-dimensional, and subject to differing conventions for file formats, data structures, coordinate spaces, units of measure, and metadata organization. When visualized, these data require differing, and often conflicting, conventions for visual representations, dimensionality, icons, color schemes, labeling, and interaction. These issues make the visualization of fused Earth science data particularly difficult. The OpenEarth Framework (OEF) is an open-source data fusion and visualization suite of software being developed at the Supercomputer Center at the University of California, San Diego. Funded by the NSF, the project is leveraging virtual globe technology from NASA’s WorldWind to create interactive 3D visualization tools that combine layered data from a variety of sources to create a holistic view of features at, above, and beneath the Earth’s surface. The OEF architecture is cross-platform, multi-threaded, modular, and based upon Java. The OEF’s modular approach yields a collection of compatible mix-and-match components for assembling custom applications. Available modules support file format handling, web service communications, data management, data filtering, user interaction, and 3D visualization. File parsers handle a variety of formal and de facto standard file formats. Each one imports data into a general-purpose data representation that supports multidimensional grids, topography, points, lines, polygons, images, and more. From there these data then may be manipulated, merged, filtered, reprojected, and visualized. Visualization features support conventional and new visualization techniques for looking at topography, tomography, maps, and feature geometry. 3D grid data such as seismic tomography may be sliced by multiple oriented cutting planes and isosurfaced to create 3D skins that trace feature boundaries within the data. Topography may be overlaid with satellite imagery along with data such as gravity and magnetics measurements. Multiple data sets may be visualized simultaneously using overlapping layers and a common 3D+time coordinate space. Data management within the OEF handles and hides the quirks of differing file formats, web protocols, storage structures, coordinate spaces, and metadata representations. Derived data are computed automatically to support interaction and visualization while the original data is left unchanged in its original form. Data is cached for better memory and network efficiency, and all visualization is accelerated by 3D graphics hardware found on today’s computers. The OpenEarth Framework project is currently prototyping the software for use in the visualization, and integration of continental scale geophysical data being produced by EarthScope-related research in the Western US. The OEF is providing researchers with new ways to display and interrogate their data and is anticipated to be a valuable tool for future EarthScope-related research.

Metadata Means Communication: The Challenges of Producing Useful Metadata

NASA Astrophysics Data System (ADS)

Edwards, P. N.; Batcheller, A. L.

2010-12-01

Metadata are increasingly perceived as an important component of data sharing systems. For instance, metadata accompanying atmospheric model output may indicate the grid size, grid type, and parameter settings used in the model configuration. We conducted a case study of a data portal in the atmospheric sciences using in-depth interviews, document review, and observation. OUr analysis revealed a number of challenges in producing useful metadata. First, creating and managing metadata required considerable effort and expertise, yet responsibility for these tasks was ill-defined and diffused among many individuals, leading to errors, failure to capture metadata, and uncertainty about the quality of the primary data. Second, metadata ended up stored in many different forms and software tools, making it hard to manage versions and transfer between formats. Third, the exact meanings of metadata categories remained unsettled and misunderstood even among a small community of domain experts -- an effect we expect to be exacerbated when scientists from other disciplines wish to use these data. In practice, we found that metadata problems due to these obstacles are often overcome through informal, personal communication, such as conversations or email. We conclude that metadata serve to communicate the context of data production from the people who produce data to those who wish to use it. Thus while formal metadata systems are often public, critical elements of metadata (those embodied in informal communication) may never be recorded. Therefore, efforts to increase data sharing should include ways to facilitate inter-investigator communication. Instead of tackling metadata challenges only on the formal level, we can improve data usability for broader communities by better supporting metadata communication.

VAMPS: a website for visualization and analysis of microbial population structures.

PubMed

Huse, Susan M; Mark Welch, David B; Voorhis, Andy; Shipunova, Anna; Morrison, Hilary G; Eren, A Murat; Sogin, Mitchell L

2014-02-05

The advent of next-generation DNA sequencing platforms has revolutionized molecular microbial ecology by making the detailed analysis of complex communities over time and space a tractable research pursuit for small research groups. However, the ability to generate 10⁵-10⁸ reads with relative ease brings with it many downstream complications. Beyond the computational resources and skills needed to process and analyze data, it is difficult to compare datasets in an intuitive and interactive manner that leads to hypothesis generation and testing. We developed the free web service VAMPS (Visualization and Analysis of Microbial Population Structures, http://vamps.mbl.edu) to address these challenges and to facilitate research by individuals or collaborating groups working on projects with large-scale sequencing data. Users can upload marker gene sequences and associated metadata; reads are quality filtered and assigned to both taxonomic structures and to taxonomy-independent clusters. A simple point-and-click interface allows users to select for analysis any combination of their own or their collaborators' private data and data from public projects, filter these by their choice of taxonomic and/or abundance criteria, and then explore these data using a wide range of analytic methods and visualizations. Each result is extensively hyperlinked to other analysis and visualization options, promoting data exploration and leading to a greater understanding of data relationships. VAMPS allows researchers using marker gene sequence data to analyze the diversity of microbial communities and the relationships between communities, to explore these analyses in an intuitive visual context, and to download data, results, and images for publication. VAMPS obviates the need for individual research groups to make the considerable investment in computational infrastructure and bioinformatic support otherwise necessary to process, analyze, and interpret massive amounts of next-generation sequence data. Any web-capable device can be used to upload, process, explore, and extract data and results from VAMPS. VAMPS encourages researchers to share sequence and metadata, and fosters collaboration between researchers of disparate biomes who recognize common patterns in shared data.

Visual analytics for semantic queries of TerraSAR-X image content

NASA Astrophysics Data System (ADS)

Espinoza-Molina, Daniela; Alonso, Kevin; Datcu, Mihai

2015-10-01

With the continuous image product acquisition of satellite missions, the size of the image archives is considerably increasing every day as well as the variety and complexity of their content, surpassing the end-user capacity to analyse and exploit them. Advances in the image retrieval field have contributed to the development of tools for interactive exploration and extraction of the images from huge archives using different parameters like metadata, key-words, and basic image descriptors. Even though we count on more powerful tools for automated image retrieval and data analysis, we still face the problem of understanding and analyzing the results. Thus, a systematic computational analysis of these results is required in order to provide to the end-user a summary of the archive content in comprehensible terms. In this context, visual analytics combines automated analysis with interactive visualizations analysis techniques for an effective understanding, reasoning and decision making on the basis of very large and complex datasets. Moreover, currently several researches are focused on associating the content of the images with semantic definitions for describing the data in a format to be easily understood by the end-user. In this paper, we present our approach for computing visual analytics and semantically querying the TerraSAR-X archive. Our approach is mainly composed of four steps: 1) the generation of a data model that explains the information contained in a TerraSAR-X product. The model is formed by primitive descriptors and metadata entries, 2) the storage of this model in a database system, 3) the semantic definition of the image content based on machine learning algorithms and relevance feedback, and 4) querying the image archive using semantic descriptors as query parameters and computing the statistical analysis of the query results. The experimental results shows that with the help of visual analytics and semantic definitions we are able to explain the image content using semantic terms and the relations between them answering questions such as what is the percentage of urban area in a region? or what is the distribution of water bodies in a city?

Inheritance rules for Hierarchical Metadata Based on ISO 19115

NASA Astrophysics Data System (ADS)

Zabala, A.; Masó, J.; Pons, X.

2012-04-01

Mainly, ISO19115 has been used to describe metadata for datasets and services. Furthermore, ISO19115 standard (as well as the new draft ISO19115-1) includes a conceptual model that allows to describe metadata at different levels of granularity structured in hierarchical levels, both in aggregated resources such as particularly series, datasets, and also in more disaggregated resources such as types of entities (feature type), types of attributes (attribute type), entities (feature instances) and attributes (attribute instances). In theory, to apply a complete metadata structure to all hierarchical levels of metadata, from the whole series to an individual feature attributes, is possible, but to store all metadata at all levels is completely impractical. An inheritance mechanism is needed to store each metadata and quality information at the optimum hierarchical level and to allow an ease and efficient documentation of metadata in both an Earth observation scenario such as a multi-satellite mission multiband imagery, as well as in a complex vector topographical map that includes several feature types separated in layers (e.g. administrative limits, contour lines, edification polygons, road lines, etc). Moreover, and due to the traditional split of maps in tiles due to map handling at detailed scales or due to the satellite characteristics, each of the previous thematic layers (e.g. 1:5000 roads for a country) or band (Landsat-5 TM cover of the Earth) are tiled on several parts (sheets or scenes respectively). According to hierarchy in ISO 19115, the definition of general metadata can be supplemented by spatially specific metadata that, when required, either inherits or overrides the general case (G.1.3). Annex H of this standard states that only metadata exceptions are defined at lower levels, so it is not necessary to generate the full registry of metadata for each level but to link particular values to the general value that they inherit. Conceptually the metadata registry is complete for each metadata hierarchical level, but at the implementation level most of the metadata elements are not stored at both levels but only at more generic one. This communication defines a metadata system that covers 4 levels, describes which metadata has to support series-layer inheritance and in which way, and how hierarchical levels are defined and stored. Metadata elements are classified according to the type of inheritance between products, series, tiles and the datasets. It explains the metadata elements classification and exemplifies it using core metadata elements. The communication also presents a metadata viewer and edition tool that uses the described model to propagate metadata elements and to show to the user a complete set of metadata for each level in a transparent way. This tool is integrated in the MiraMon GIS software.

The role of metadata in managing large environmental science datasets. Proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melton, R.B.; DeVaney, D.M.; French, J. C.

1995-06-01

The purpose of this workshop was to bring together computer science researchers and environmental sciences data management practitioners to consider the role of metadata in managing large environmental sciences datasets. The objectives included: establishing a common definition of metadata; identifying categories of metadata; defining problems in managing metadata; and defining problems related to linking metadata with primary data.

Web based tools for visualizing imaging data and development of XNATView, a zero footprint image viewer

PubMed Central

Gutman, David A.; Dunn, William D.; Cobb, Jake; Stoner, Richard M.; Kalpathy-Cramer, Jayashree; Erickson, Bradley

2014-01-01

Advances in web technologies now allow direct visualization of imaging data sets without necessitating the download of large file sets or the installation of software. This allows centralization of file storage and facilitates image review and analysis. XNATView is a light framework recently developed in our lab to visualize DICOM images stored in The Extensible Neuroimaging Archive Toolkit (XNAT). It consists of a PyXNAT-based framework to wrap around the REST application programming interface (API) and query the data in XNAT. XNATView was developed to simplify quality assurance, help organize imaging data, and facilitate data sharing for intra- and inter-laboratory collaborations. Its zero-footprint design allows the user to connect to XNAT from a web browser, navigate through projects, experiments, and subjects, and view DICOM images with accompanying metadata all within a single viewing instance. PMID:24904399

GEO Label Web Services for Dynamic and Effective Communication of Geospatial Metadata Quality

NASA Astrophysics Data System (ADS)

Lush, Victoria; Nüst, Daniel; Bastin, Lucy; Masó, Joan; Lumsden, Jo

2014-05-01

We present demonstrations of the GEO label Web services and their integration into a prototype extension of the GEOSS portal (http://scgeoviqua.sapienzaconsulting.com/web/guest/geo_home), the GMU portal (http://gis.csiss.gmu.edu/GADMFS/) and a GeoNetwork catalog application (http://uncertdata.aston.ac.uk:8080/geonetwork/srv/eng/main.home). The GEO label is designed to communicate, and facilitate interrogation of, geospatial quality information with a view to supporting efficient and effective dataset selection on the basis of quality, trustworthiness and fitness for use. The GEO label which we propose was developed and evaluated according to a user-centred design (UCD) approach in order to maximise the likelihood of user acceptance once deployed. The resulting label is dynamically generated from producer metadata in ISO or FDGC format, and incorporates user feedback on dataset usage, ratings and discovered issues, in order to supply a highly informative summary of metadata completeness and quality. The label was easily incorporated into a community portal as part of the GEO Architecture Implementation Programme (AIP-6) and has been successfully integrated into a prototype extension of the GEOSS portal, as well as the popular metadata catalog and editor, GeoNetwork. The design of the GEO label was based on 4 user studies conducted to: (1) elicit initial user requirements; (2) investigate initial user views on the concept of a GEO label and its potential role; (3) evaluate prototype label visualizations; and (4) evaluate and validate physical GEO label prototypes. The results of these studies indicated that users and producers support the concept of a label with drill-down interrogation facility, combining eight geospatial data informational aspects, namely: producer profile, producer comments, lineage information, standards compliance, quality information, user feedback, expert reviews, and citations information. These are delivered as eight facets of a wheel-like label, which are coloured according to metadata availability and are clickable to allow a user to engage with the original metadata and explore specific aspects in more detail. To support this graphical representation and allow for wider deployment architectures we have implemented two Web services, a PHP and a Java implementation, that generate GEO label representations by combining producer metadata (from standard catalogues or other published locations) with structured user feedback. Both services accept encoded URLs of publicly available metadata documents or metadata XML files as HTTP POST and GET requests and apply XPath and XSLT mappings to transform producer and feedback XML documents into clickable SVG GEO label representations. The label and services are underpinned by two XML-based quality models. The first is a producer model that extends ISO 19115 and 19157 to allow fuller citation of reference data, presentation of pixel- and dataset- level statistical quality information, and encoding of 'traceability' information on the lineage of an actual quality assessment. The second is a user quality model (realised as a feedback server and client) which allows reporting and query of ratings, usage reports, citations, comments and other domain knowledge. Both services are Open Source and are available on GitHub at https://github.com/lushv/geolabel-service and https://github.com/52North/GEO-label-java. The functionality of these services can be tested using our GEO label generation demos, available online at http://www.geolabel.net/demo.html and http://geoviqua.dev.52north.org/glbservice/index.jsf.

Building Format-Agnostic Metadata Repositories

NASA Astrophysics Data System (ADS)

Cechini, M.; Pilone, D.

2010-12-01

This presentation will discuss the problems that surround persisting and discovering metadata in multiple formats; a set of tenets that must be addressed in a solution; and NASA’s Earth Observing System (EOS) ClearingHOuse’s (ECHO) proposed approach. In order to facilitate cross-discipline data analysis, Earth Scientists will potentially interact with more than one data source. The most common data discovery paradigm relies on services and/or applications facilitating the discovery and presentation of metadata. What may not be common are the formats in which the metadata are formatted. As the number of sources and datasets utilized for research increases, it becomes more likely that a researcher will encounter conflicting metadata formats. Metadata repositories, such as the EOS ClearingHOuse (ECHO), along with data centers, must identify ways to address this issue. In order to define the solution to this problem, the following tenets are identified: - There exists a set of ‘core’ metadata fields recommended for data discovery. - There exists a set of users who will require the entire metadata record for advanced analysis. - There exists a set of users who will require a ‘core’ set of metadata fields for discovery only. - There will never be a cessation of new formats or a total retirement of all old formats. - Users should be presented metadata in a consistent format. ECHO has undertaken an effort to transform its metadata ingest and discovery services in order to support the growing set of metadata formats. In order to address the previously listed items, ECHO’s new metadata processing paradigm utilizes the following approach: - Identify a cross-format set of ‘core’ metadata fields necessary for discovery. - Implement format-specific indexers to extract the ‘core’ metadata fields into an optimized query capability. - Archive the original metadata in its entirety for presentation to users requiring the full record. - Provide on-demand translation of ‘core’ metadata to any supported result format. With this identified approach, the Earth Scientist is provided with a consistent data representation as they interact with a variety of datasets that utilize multiple metadata formats. They are then able to focus their efforts on the more critical research activities which they are undertaking.

SPOCS: software for predicting and visualizing orthology/paralogy relationships among genomes.

PubMed

Curtis, Darren S; Phillips, Aaron R; Callister, Stephen J; Conlan, Sean; McCue, Lee Ann

2013-10-15

At the rate that prokaryotic genomes can now be generated, comparative genomics studies require a flexible method for quickly and accurately predicting orthologs among the rapidly changing set of genomes available. SPOCS implements a graph-based ortholog prediction method to generate a simple tab-delimited table of orthologs and in addition, html files that provide a visualization of the predicted ortholog/paralog relationships to which gene/protein expression metadata may be overlaid. A SPOCS web application is freely available at http://cbb.pnnl.gov/portal/tools/spocs.html. Source code for Linux systems is also freely available under an open source license at http://cbb.pnnl.gov/portal/software/spocs.html; the Boost C++ libraries and BLAST are required.

Making Metadata Better with CMR and MMT

NASA Technical Reports Server (NTRS)

Gilman, Jason Arthur; Shum, Dana

2016-01-01

Ensuring complete, consistent and high quality metadata is a challenge for metadata providers and curators. The CMR and MMT systems provide providers and curators options to build in metadata quality from the start and also assess and improve the quality of already existing metadata.

NASA's Big Earth Data Initiative Accomplishments

NASA Technical Reports Server (NTRS)

Klene, Stephan A.; Pauli, Elisheva; Pressley, Natalie N.; Cechini, Matthew F.; McInerney, Mark

2017-01-01

The goal of NASA's effort for BEDI is to improve the usability, discoverability, and accessibility of Earth Observation data in support of societal benefit areas. Accomplishments: In support of BEDI goals, datasets have been entered into Common Metadata Repository(CMR), made available via the Open-source Project for a Network Data Access Protocol (OPeNDAP), have a Digital Object Identifier (DOI) registered for the dataset, and to support fast visualization many layers have been added in to the Global Imagery Browse Services (GIBS).

NASA's Big Earth Data Initiative Accomplishments

NASA Astrophysics Data System (ADS)

Klene, S. A.; Pauli, E.; Pressley, N. N.; Cechini, M. F.; McInerney, M.

2017-12-01

The goal of NASA's effort for BEDI is to improve the usability, discoverability, and accessibility of Earth Observation data in support of societal benefit areas. Accomplishments: In support of BEDI goals, datasets have been entered into Common Metadata Repository(CMR), made available via the Open-source Project for a Network Data Access Protocol (OPeNDAP), have a Digital Object Identifier (DOI) registered for the dataset, and to support fast visualization many layers have been added in to the Global Imagery Browse Service(GIBS)

ASDC Advances in the Utilization of Microservices and Hybrid Cloud Environments

NASA Astrophysics Data System (ADS)

Baskin, W. E.; Herbert, A.; Mazaika, A.; Walter, J.

2017-12-01

The Atmospheric Science Data Center (ASDC) is transitioning many of its software tools and applications to standalone microservices deployable in a hybrid cloud, offering benefits such as scalability and efficient environment management. This presentation features several projects the ASDC staff have implemented leveraging the OpenShift Container Application Platform and OpenStack Hybrid Cloud Environment focusing on key tools and techniques applied to: Earth Science data processing Spatial-Temporal metadata generation, validation, repair, and curation Archived Data discovery, visualization, and access

Treemap Visualization for Space Situational Awareness

DTIC Science & Technology

2015-10-18

virtually any display like a table with textual metadata, a hyperlink to a web page, or another treemap. Animation can be used to “explode” the tile to...release; distribution unlimited. 88ABW Cleared 07/30/2015; 88ABW-2015-3828. In Fig. 7 shown below, we have chosen to select “Size By Radar Cross...Section ( RCS )”. We’re still looking at the same Unclassified Space Catalog scenario, but we’ve simply chosen a different “Size by” option, and the view

ArrayWiki: an enabling technology for sharing public microarray data repositories and meta-analyses

PubMed Central

Stokes, Todd H; Torrance, JT; Li, Henry; Wang, May D

2008-01-01

Background A survey of microarray databases reveals that most of the repository contents and data models are heterogeneous (i.e., data obtained from different chip manufacturers), and that the repositories provide only basic biological keywords linking to PubMed. As a result, it is difficult to find datasets using research context or analysis parameters information beyond a few keywords. For example, to reduce the "curse-of-dimension" problem in microarray analysis, the number of samples is often increased by merging array data from different datasets. Knowing chip data parameters such as pre-processing steps (e.g., normalization, artefact removal, etc), and knowing any previous biological validation of the dataset is essential due to the heterogeneity of the data. However, most of the microarray repositories do not have meta-data information in the first place, and do not have a a mechanism to add or insert this information. Thus, there is a critical need to create "intelligent" microarray repositories that (1) enable update of meta-data with the raw array data, and (2) provide standardized archiving protocols to minimize bias from the raw data sources. Results To address the problems discussed, we have developed a community maintained system called ArrayWiki that unites disparate meta-data of microarray meta-experiments from multiple primary sources with four key features. First, ArrayWiki provides a user-friendly knowledge management interface in addition to a programmable interface using standards developed by Wikipedia. Second, ArrayWiki includes automated quality control processes (caCORRECT) and novel visualization methods (BioPNG, Gel Plots), which provide extra information about data quality unavailable in other microarray repositories. Third, it provides a user-curation capability through the familiar Wiki interface. Fourth, ArrayWiki provides users with simple text-based searches across all experiment meta-data, and exposes data to search engine crawlers (Semantic Agents) such as Google to further enhance data discovery. Conclusions Microarray data and meta information in ArrayWiki are distributed and visualized using a novel and compact data storage format, BioPNG. Also, they are open to the research community for curation, modification, and contribution. By making a small investment of time to learn the syntax and structure common to all sites running MediaWiki software, domain scientists and practioners can all contribute to make better use of microarray technologies in research and medical practices. ArrayWiki is available at . PMID:18541053

Arteriovenous Malformations

MedlinePlus

Arteriovenous malformations (AVMs) are defects in your vascular system. The vascular system includes arteries, veins, and capillaries. Arteries carry blood away from the heart to other organs; veins carry blood back to the heart. Capillaries connect the arteries and veins. An ...

Evolution in Metadata Quality: Common Metadata Repository's Role in NASA Curation Efforts

NASA Technical Reports Server (NTRS)

Gilman, Jason; Shum, Dana; Baynes, Katie

2016-01-01

Metadata Quality is one of the chief drivers of discovery and use of NASA EOSDIS (Earth Observing System Data and Information System) data. Issues with metadata such as lack of completeness, inconsistency, and use of legacy terms directly hinder data use. As the central metadata repository for NASA Earth Science data, the Common Metadata Repository (CMR) has a responsibility to its users to ensure the quality of CMR search results. This poster covers how we use humanizers, a technique for dealing with the symptoms of metadata issues, as well as our plans for future metadata validation enhancements. The CMR currently indexes 35K collections and 300M granules.

Describing environmental public health data: implementing a descriptive metadata standard on the environmental public health tracking network.

PubMed

Patridge, Jeff; Namulanda, Gonza

2008-01-01

The Environmental Public Health Tracking (EPHT) Network provides an opportunity to bring together diverse environmental and health effects data by integrating}?> local, state, and national databases of environmental hazards, environmental exposures, and health effects. To help users locate data on the EPHT Network, the network will utilize descriptive metadata that provide critical information as to the purpose, location, content, and source of these data. Since 2003, the Centers for Disease Control and Prevention's EPHT Metadata Subgroup has been working to initiate the creation and use of descriptive metadata. Efforts undertaken by the group include the adoption of a metadata standard, creation of an EPHT-specific metadata profile, development of an open-source metadata creation tool, and promotion of the creation of descriptive metadata by changing the perception of metadata in the public health culture.

Metadata: Standards for Retrieving WWW Documents (and Other Digitized and Non-Digitized Resources)

NASA Astrophysics Data System (ADS)

Rusch-Feja, Diann

The use of metadata for indexing digitized and non-digitized resources for resource discovery in a networked environment is being increasingly implemented all over the world. Greater precision is achieved using metadata than relying on universal search engines and furthermore, meta-data can be used as filtering mechanisms for search results. An overview of various metadata sets is given, followed by a more focussed presentation of Dublin Core Metadata including examples of sub-elements and qualifiers. Especially the use of the Dublin Core Relation element provides connections between the metadata of various related electronic resources, as well as the metadata for physical, non-digitized resources. This facilitates more comprehensive search results without losing precision and brings together different genres of information which would otherwise be only searchable in separate databases. Furthermore, the advantages of Dublin Core Metadata in comparison with library cataloging and the use of universal search engines are discussed briefly, followed by a listing of types of implementation of Dublin Core Metadata.

Department of the Interior metadata implementation guide—Framework for developing the metadata component for data resource management

USGS Publications Warehouse

Obuch, Raymond C.; Carlino, Jennifer; Zhang, Lin; Blythe, Jonathan; Dietrich, Christopher; Hawkinson, Christine

2018-04-12

The Department of the Interior (DOI) is a Federal agency with over 90,000 employees across 10 bureaus and 8 agency offices. Its primary mission is to protect and manage the Nation’s natural resources and cultural heritage; provide scientific and other information about those resources; and honor its trust responsibilities or special commitments to American Indians, Alaska Natives, and affiliated island communities. Data and information are critical in day-to-day operational decision making and scientific research. DOI is committed to creating, documenting, managing, and sharing high-quality data and metadata in and across its various programs that support its mission. Documenting data through metadata is essential in realizing the value of data as an enterprise asset. The completeness, consistency, and timeliness of metadata affect users’ ability to search for and discover the most relevant data for the intended purpose; and facilitates the interoperability and usability of these data among DOI bureaus and offices. Fully documented metadata describe data usability, quality, accuracy, provenance, and meaning.Across DOI, there are different maturity levels and phases of information and metadata management implementations. The Department has organized a committee consisting of bureau-level points-of-contacts to collaborate on the development of more consistent, standardized, and more effective metadata management practices and guidance to support this shared mission and the information needs of the Department. DOI’s metadata implementation plans establish key roles and responsibilities associated with metadata management processes, procedures, and a series of actions defined in three major metadata implementation phases including: (1) Getting started—Planning Phase, (2) Implementing and Maintaining Operational Metadata Management Phase, and (3) the Next Steps towards Improving Metadata Management Phase. DOI’s phased approach for metadata management addresses some of the major data and metadata management challenges that exist across the diverse missions of the bureaus and offices. All employees who create, modify, or use data are involved with data and metadata management. Identifying, establishing, and formalizing the roles and responsibilities associated with metadata management are key to institutionalizing a framework of best practices, methodologies, processes, and common approaches throughout all levels of the organization; these are the foundation for effective data resource management. For executives and managers, metadata management strengthens their overarching views of data assets, holdings, and data interoperability; and clarifies how metadata management can help accelerate the compliance of multiple policy mandates. For employees, data stewards, and data professionals, formalized metadata management will help with the consistency of definitions, and approaches addressing data discoverability, data quality,  and data lineage. In addition to data professionals and others  associated with information technology; data stewards and program subject matter experts take on important metadata management roles and responsibilities as data flow through their respective business and science-related workflows.  The responsibilities of establishing, practicing, and  governing the actions associated with their specific metadata management roles are critical to successful metadata implementation.

Making Interoperability Easier with the NASA Metadata Management Tool

NASA Astrophysics Data System (ADS)

Shum, D.; Reese, M.; Pilone, D.; Mitchell, A. E.

2016-12-01

ISO 19115 has enabled interoperability amongst tools, yet many users find it hard to build ISO metadata for their collections because it can be large and overly flexible for their needs. The Metadata Management Tool (MMT), part of NASA's Earth Observing System Data and Information System (EOSDIS), offers users a modern, easy to use browser based tool to develop ISO compliant metadata. Through a simplified UI experience, metadata curators can create and edit collections without any understanding of the complex ISO-19115 format, while still generating compliant metadata. The MMT is also able to assess the completeness of collection level metadata by evaluating it against a variety of metadata standards. The tool provides users with clear guidance as to how to change their metadata in order to improve their quality and compliance. It is based on NASA's Unified Metadata Model for Collections (UMM-C) which is a simpler metadata model which can be cleanly mapped to ISO 19115. This allows metadata authors and curators to meet ISO compliance requirements faster and more accurately. The MMT and UMM-C have been developed in an agile fashion, with recurring end user tests and reviews to continually refine the tool, the model and the ISO mappings. This process is allowing for continual improvement and evolution to meet the community's needs.

New concepts for building vocabulary for cell image ontologies.

PubMed

Plant, Anne L; Elliott, John T; Bhat, Talapady N

2011-12-21

There are significant challenges associated with the building of ontologies for cell biology experiments including the large numbers of terms and their synonyms. These challenges make it difficult to simultaneously query data from multiple experiments or ontologies. If vocabulary terms were consistently used and reused across and within ontologies, queries would be possible through shared terms. One approach to achieving this is to strictly control the terms used in ontologies in the form of a pre-defined schema, but this approach limits the individual researcher's ability to create new terms when needed to describe new experiments. Here, we propose the use of a limited number of highly reusable common root terms, and rules for an experimentalist to locally expand terms by adding more specific terms under more general root terms to form specific new vocabulary hierarchies that can be used to build ontologies. We illustrate the application of the method to build vocabularies and a prototype database for cell images that uses a visual data-tree of terms to facilitate sophisticated queries based on a experimental parameters. We demonstrate how the terminology might be extended by adding new vocabulary terms into the hierarchy of terms in an evolving process. In this approach, image data and metadata are handled separately, so we also describe a robust file-naming scheme to unambiguously identify image and other files associated with each metadata value. The prototype database http://sbd.nist.gov/ consists of more than 2000 images of cells and benchmark materials, and 163 metadata terms that describe experimental details, including many details about cell culture and handling. Image files of interest can be retrieved, and their data can be compared, by choosing one or more relevant metadata values as search terms. Metadata values for any dataset can be compared with corresponding values of another dataset through logical operations. Organizing metadata for cell imaging experiments under a framework of rules that include highly reused root terms will facilitate the addition of new terms into a vocabulary hierarchy and encourage the reuse of terms. These vocabulary hierarchies can be converted into XML schema or RDF graphs for displaying and querying, but this is not necessary for using it to annotate cell images. Vocabulary data trees from multiple experiments or laboratories can be aligned at the root terms to facilitate query development. This approach of developing vocabularies is compatible with the major advances in database technology and could be used for building the Semantic Web.

New concepts for building vocabulary for cell image ontologies

PubMed Central

2011-01-01

Background There are significant challenges associated with the building of ontologies for cell biology experiments including the large numbers of terms and their synonyms. These challenges make it difficult to simultaneously query data from multiple experiments or ontologies. If vocabulary terms were consistently used and reused across and within ontologies, queries would be possible through shared terms. One approach to achieving this is to strictly control the terms used in ontologies in the form of a pre-defined schema, but this approach limits the individual researcher's ability to create new terms when needed to describe new experiments. Results Here, we propose the use of a limited number of highly reusable common root terms, and rules for an experimentalist to locally expand terms by adding more specific terms under more general root terms to form specific new vocabulary hierarchies that can be used to build ontologies. We illustrate the application of the method to build vocabularies and a prototype database for cell images that uses a visual data-tree of terms to facilitate sophisticated queries based on a experimental parameters. We demonstrate how the terminology might be extended by adding new vocabulary terms into the hierarchy of terms in an evolving process. In this approach, image data and metadata are handled separately, so we also describe a robust file-naming scheme to unambiguously identify image and other files associated with each metadata value. The prototype database http://sbd.nist.gov/ consists of more than 2000 images of cells and benchmark materials, and 163 metadata terms that describe experimental details, including many details about cell culture and handling. Image files of interest can be retrieved, and their data can be compared, by choosing one or more relevant metadata values as search terms. Metadata values for any dataset can be compared with corresponding values of another dataset through logical operations. Conclusions Organizing metadata for cell imaging experiments under a framework of rules that include highly reused root terms will facilitate the addition of new terms into a vocabulary hierarchy and encourage the reuse of terms. These vocabulary hierarchies can be converted into XML schema or RDF graphs for displaying and querying, but this is not necessary for using it to annotate cell images. Vocabulary data trees from multiple experiments or laboratories can be aligned at the root terms to facilitate query development. This approach of developing vocabularies is compatible with the major advances in database technology and could be used for building the Semantic Web. PMID:22188658

Instrument workstation for the EGSE of the Near Infrared Spectro-Photometer instrument (NISP) of the EUCLID mission

NASA Astrophysics Data System (ADS)

Trifoglio, M.; Gianotti, F.; Conforti, V.; Franceschi, E.; Stephen, J. B.; Bulgarelli, A.; Fioretti, V.; Maiorano, E.; Nicastro, L.; Valenziano, L.; Zoli, A.; Auricchio, N.; Balestra, A.; Bonino, D.; Bonoli, C.; Bortoletto, F.; Capobianco, V.; Chiarusi, T.; Corcione, L.; Debei, S.; De Rosa, A.; Dusini, S.; Fornari, F.; Giacomini, F.; Guizzo, G. P.; Ligori, S.; Margiotta, A.; Mauri, N.; Medinaceli, E.; Morgante, G.; Patrizii, L.; Sirignano, C.; Sirri, G.; Sortino, F.; Stanco, L.; Tenti, M.

2016-07-01

The NISP instrument on board the Euclid ESA mission will be developed and tested at different levels of integration using various test equipment which shall be designed and procured through a collaborative and coordinated effort. The NISP Instrument Workstation (NI-IWS) will be part of the EGSE configuration that will support the NISP AIV/AIT activities from the NISP Warm Electronics level up to the launch of Euclid. One workstation is required for the NISP EQM/AVM, and a second one for the NISP FM. Each workstation will follow the respective NISP model after delivery to ESA for Payload and Satellite AIV/AIT and launch. At these levels the NI-IWS shall be configured as part of the Payload EGSE, the System EGSE, and the Launch EGSE, respectively. After launch, the NI-IWS will be also re-used in the Euclid Ground Segment in order to support the Commissioning and Performance Verification (CPV) phase, and for troubleshooting purposes during the operational phase. The NI-IWS is mainly aimed at the local storage in a suitable format of the NISP instrument data and metadata, at local retrieval, processing and display of the stored data for on-line instrument assessment, and at the remote retrieval of the stored data for off-line analysis on other computers. We describe the design of the IWS software that will create a suitable interface to the external systems in each of the various configurations envisaged at the different levels, and provide the capabilities required to monitor and verify the instrument functionalities and performance throughout all phases of the NISP lifetime.

Comparison of index velocity measurements made with a horizontal acoustic Doppler current profiler

USGS Publications Warehouse

Jackson, P. Ryan; Johnson, Kevin K.; Duncker, James J.

2012-01-01

The State of Illinois' annual withdrawal from Lake Michigan is limited by a U.S. Supreme Court decree, and the U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago Sanitary and Ship Canal (CSSC) near Lemont, Illinois as a part of the Lake Michigan Diversion Accounting overseen by the U.S. Army Corps of Engineers, Chicago District. Every 5 years, a technical review committee consisting of practicing engineers and academics is convened to review the U.S. Geological Survey's streamgage practices in the CSSC near Lemont, Illinois. The sixth technical review committee raised a number of questions concerning the flows and streamgage practices in the CSSC near Lemont and this report provides answers to many of those questions. In addition, it is the purpose of this report to examine the index velocity meters in use at Lemont and determine whether the acoustic velocity meter (AVM), which is now the primary index velocity meter, can be replaced by the horizontal acoustic Doppler current profiler (H-ADCP), which is currently the backup meter. Application of the AVM and H-ADCP to index velocity measurements in the CSSC near Lemont, Illinois, has produced good ratings to date. The site is well suited to index velocity measurements in spite of the large range of velocities and highly unsteady flows at the site. Flow variability arises from a range of sources: operation of the waterway through control structures, lockage-generated disturbances, commercial and recreational traffic, industrial withdrawals and discharges, natural inflows, seiches, and storm events. The influences of these factors on the index velocity measurements at Lemont is examined in detail in this report. Results of detailed data comparisons and flow analyses show that use of bank-mounted instrumentation such as the AVM and H-ADCP appears to be the best option for index velocity measurement in the CSSC near Lemont. Comparison of the rating curves for the AVM and H-ADCP demonstrates that the H-ADCP is a suitable replacement for the AVM as the primary index velocity meter in the CSSC near Lemont. A key component to Lake Michigan Diversion Accounting is the USGS gaging station on the CSSC near Lemont, Illinois. The importance of this gaging station in monitoring withdrawals from Lake Michigan has made it one of the most highly scrutinized gaging stations in the country. Any changes in streamgaging practices at this gaging station requires detailed analysis to ensure the change will not adversely affect the ability of the USGS to accurately monitor flows. This report provides a detailed analysis of the flow structure and index velocity measurements in the CSSC near Lemont, Illinois, to ensure that decisions regarding the future of this streamgage are made with the best possible understanding of the site and the characteristics of the flow.

GraphMeta: Managing HPC Rich Metadata in Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Dong; Chen, Yong; Carns, Philip

High-performance computing (HPC) systems face increasingly critical metadata management challenges, especially in the approaching exascale era. These challenges arise not only from exploding metadata volumes, but also from increasingly diverse metadata, which contains data provenance and arbitrary user-defined attributes in addition to traditional POSIX metadata. This ‘rich’ metadata is becoming critical to supporting advanced data management functionality such as data auditing and validation. In our prior work, we identified a graph-based model as a promising solution to uniformly manage HPC rich metadata due to its flexibility and generality. However, at the same time, graph-based HPC rich metadata anagement also introducesmore » significant challenges to the underlying infrastructure. In this study, we first identify the challenges on the underlying infrastructure to support scalable, high-performance rich metadata management. Based on that, we introduce GraphMeta, a graphbased engine designed for this use case. It achieves performance scalability by introducing a new graph partitioning algorithm and a write-optimal storage engine. We evaluate GraphMeta under both synthetic and real HPC metadata workloads, compare it with other approaches, and demonstrate its advantages in terms of efficiency and usability for rich metadata management in HPC systems.« less

Arteriovenous Malformations and Other Vascular Lesions of the Central Nervous System

MedlinePlus

... Neurological Disorders and Stroke (NINDS) is to seek fundamental knowledge about the brain and spinal cord and ... NINDS-funded research hopes to determine molecular pathways fundamental to the formation of brain AVMs, which may ...

Study of Terrestrial Radio Determination : Applications and Technology

DOT National Transportation Integrated Search

1979-02-01

The report describes the results of a study of terrestrial radio determination (TRD) applications and technology. Considerable emphasis has been placed on automatic automotive vehicle location or monitoring (AVL or AVM) systems because almost all of ...

Evaluation of the Monitor-CTA Automatic Vehicle Monitoring System

DOT National Transportation Integrated Search

1974-03-01

In June 1972 the Urban Mass Transportation Administration requested that the Transportation System Center of DOT perform an evaluation of the CTA (Chicago Transit Authority) Monitor-Automatic Vehicle Monitor (AVM) system. TSC planned the overall eval...

"Dual pathology" and the significance of surgical outcome in "Dostoewsky's epilepsy".

PubMed

Vera, C L; Patel, S J; Naso, W

2000-03-01

A patient with a right occipital arterio-venous malformation (AVM) and seizures heralded by "lights", and experiencing "ecstasy" underwent a right occipital lobectomy after the AVM was embolized. Thereafter, seizures began with motor arrest and lip smacking, but never again with "light and ecstasy". A right temporal lobectomy and electrocorticogram (E.Co.G) were performed under local anesthesia four years after occipital lobectomy. Abundant spiking activity was recorded from the right hippocampus which showed gliosis and neuronal loss in the pathology studies. Electrical stimulation of the lateral and basal temporal cortices failed to elicit the vision of "lights" or the experience of "ecstasy". The patient has had two seizures in the last two years as a result of a lapse in taking his anti-convulsant medication. He now lives alone, seizure-free. The possible abnormally induced functional network organization and structures involved in the production of the "ecstasy" phenomenon are discussed.

Pelvic arteriovenous malformation treated by transarterial glue embolisation combining proximal balloon occlusion and devascularisation of multiple feeding arteries.

PubMed

Murakami, Kenji; Yamada, Takayuki; Kumano, Reiko; Nakajima, Yasuo

2014-06-06

We present a case of a 70-year-old man with abdominal aortic aneurysm and coincident pelvic arteriovenous malformation (AVM). Before the operation for the aneurysm, we embolised the pelvic AVM that had multiple feeding arteries and an aneurysmal-dilated draining vein. After decreasing the number of the feeding arteries by coil embolisation, an n-butyl-2-cyanoacrylate/lipiodol mixture (1:1) was injected into the prominent feeding artery and nidus with proximal balloon occlusion of the right internal iliac artery to decrease the flow to the nidus. The mixture (1:4-8) was also added for the finer feeding arteries that became apparent after the initial procedure to embolise the rest of the nidus. A follow-up study showed no contrast enhancement of the nidus and aneurysmal draining vein. 2014 BMJ Publishing Group Ltd.

Enhanced biocompatibility of ZnS:Mn quantum dots encapsulated with Aloe vera extract for therapeutic applications

NASA Astrophysics Data System (ADS)

Anilkumar, M.; Bindu, K. R.; Sneha Saj, A.; Anila, E. I.

2016-08-01

Toxicity of nanoparticles remains to be a major issue in their application to the biomedical field. Aloe vera (AV) is one of the most widely exploited medicinal plants that have a multitude of amazing properties in the field of medicine. Methanol extract of Aloe vera can be used as a novel stabilising agent for quantum dots to reduce toxicity. We report the synthesis, structural characterization, antibacterial activity and cytotoxicity studies of ZnS:Mn quantum dots synthesized by the colloidal precipitation method, using methanol extract of Aloe vera (AVME) as the capping agent. The ZnS:Mn quantum dots capped with AVME exhibit superior performances in biocompatibility and antibacterial activity compared with ZnS:Mn quantum dots without encapsulation. Project supported by the Science and Engineering Research Board (SERB), Department of Science and Technology (DST), Government of India.

Metabolonote: A Wiki-Based Database for Managing Hierarchical Metadata of Metabolome Analyses

PubMed Central

Ara, Takeshi; Enomoto, Mitsuo; Arita, Masanori; Ikeda, Chiaki; Kera, Kota; Yamada, Manabu; Nishioka, Takaaki; Ikeda, Tasuku; Nihei, Yoshito; Shibata, Daisuke; Kanaya, Shigehiko; Sakurai, Nozomu

2015-01-01

Metabolomics – technology for comprehensive detection of small molecules in an organism – lags behind the other “omics” in terms of publication and dissemination of experimental data. Among the reasons for this are difficulty precisely recording information about complicated analytical experiments (metadata), existence of various databases with their own metadata descriptions, and low reusability of the published data, resulting in submitters (the researchers who generate the data) being insufficiently motivated. To tackle these issues, we developed Metabolonote, a Semantic MediaWiki-based database designed specifically for managing metabolomic metadata. We also defined a metadata and data description format, called “Togo Metabolome Data” (TogoMD), with an ID system that is required for unique access to each level of the tree-structured metadata such as study purpose, sample, analytical method, and data analysis. Separation of the management of metadata from that of data and permission to attach related information to the metadata provide advantages for submitters, readers, and database developers. The metadata are enriched with information such as links to comparable data, thereby functioning as a hub of related data resources. They also enhance not only readers’ understanding and use of data but also submitters’ motivation to publish the data. The metadata are computationally shared among other systems via APIs, which facilitate the construction of novel databases by database developers. A permission system that allows publication of immature metadata and feedback from readers also helps submitters to improve their metadata. Hence, this aspect of Metabolonote, as a metadata preparation tool, is complementary to high-quality and persistent data repositories such as MetaboLights. A total of 808 metadata for analyzed data obtained from 35 biological species are published currently. Metabolonote and related tools are available free of cost at http://metabolonote.kazusa.or.jp/. PMID:25905099

Metabolonote: a wiki-based database for managing hierarchical metadata of metabolome analyses.

PubMed

Ara, Takeshi; Enomoto, Mitsuo; Arita, Masanori; Ikeda, Chiaki; Kera, Kota; Yamada, Manabu; Nishioka, Takaaki; Ikeda, Tasuku; Nihei, Yoshito; Shibata, Daisuke; Kanaya, Shigehiko; Sakurai, Nozomu

2015-01-01

Metabolomics - technology for comprehensive detection of small molecules in an organism - lags behind the other "omics" in terms of publication and dissemination of experimental data. Among the reasons for this are difficulty precisely recording information about complicated analytical experiments (metadata), existence of various databases with their own metadata descriptions, and low reusability of the published data, resulting in submitters (the researchers who generate the data) being insufficiently motivated. To tackle these issues, we developed Metabolonote, a Semantic MediaWiki-based database designed specifically for managing metabolomic metadata. We also defined a metadata and data description format, called "Togo Metabolome Data" (TogoMD), with an ID system that is required for unique access to each level of the tree-structured metadata such as study purpose, sample, analytical method, and data analysis. Separation of the management of metadata from that of data and permission to attach related information to the metadata provide advantages for submitters, readers, and database developers. The metadata are enriched with information such as links to comparable data, thereby functioning as a hub of related data resources. They also enhance not only readers' understanding and use of data but also submitters' motivation to publish the data. The metadata are computationally shared among other systems via APIs, which facilitate the construction of novel databases by database developers. A permission system that allows publication of immature metadata and feedback from readers also helps submitters to improve their metadata. Hence, this aspect of Metabolonote, as a metadata preparation tool, is complementary to high-quality and persistent data repositories such as MetaboLights. A total of 808 metadata for analyzed data obtained from 35 biological species are published currently. Metabolonote and related tools are available free of cost at http://metabolonote.kazusa.or.jp/.

Metadata (MD)

Treesearch

Robert E. Keane

2006-01-01

The Metadata (MD) table in the FIREMON database is used to record any information about the sampling strategy or data collected using the FIREMON sampling procedures. The MD method records metadata pertaining to a group of FIREMON plots, such as all plots in a specific FIREMON project. FIREMON plots are linked to metadata using a unique metadata identifier that is...

Evaluating the Interdisciplinary Discoverability of Data

NASA Astrophysics Data System (ADS)

Gordon, S.; Habermann, T.

2017-12-01

Documentation needs are similar across communities. Communities tend to agree on many of the basic concepts necessary for discovery. Shared concepts such as a title or a description of the data exist in most metadata dialects. Many dialects have been designed and recommendations implemented to create metadata valuable for data discovery. These implementations can create barriers to discovering the right data. How can we ensure that the documentation we curate will be discoverable and understandable by researchers outside of our own disciplines and organizations? Since communities tend to use and understand many of the same documentation concepts, the barriers to interdisciplinary discovery are caused by the differences in the implementation. Thus tools and methods designed for the conceptual layer that evaluate records for documentation concepts, regardless of the dialect, can be effective in identifying opportunities for improvement and providing guidance. The Metadata Evaluation Web Service combined with a Jupyter Notebook interface allows a user to gather insight about a collection of records with respect to different communities' conceptual recommendations. It accomplishes this via data visualizations and provides links to implementation specific guidance on the ESIP Wiki for each recommendation applied to the collection. By utilizing these curation tools as part of an iterative process the data's impact can be increased by making it discoverable to a greater scientific and research community. Due to the conceptual focus of the methods and tools used, they can be utilized by any community or organization regardless of their documentation dialect or tools.

Documentation Resources on the ESIP Wiki

NASA Technical Reports Server (NTRS)

Habermann, Ted; Kozimor, John; Gordon, Sean

2017-01-01

The ESIP community includes data providers and users that communicate with one another through datasets and metadata that describe them. Improving this communication depends on consistent high-quality metadata. The ESIP Documentation Cluster and the wiki play an important central role in facilitating this communication. We will describe and demonstrate sections of the wiki that provide information about metadata concept definitions, metadata recommendation, metadata dialects, and guidance pages. We will also describe and demonstrate the ISO Explorer, a tool that the community is developing to help metadata creators.

The OpenEarth Framework (OEF) for the 3D Visualization of Integrated Earth Science Data

NASA Astrophysics Data System (ADS)

Nadeau, David; Moreland, John; Baru, Chaitan; Crosby, Chris

2010-05-01

Data integration is increasingly important as we strive to combine data from disparate sources and assemble better models of the complex processes operating at the Earth's surface and within its interior. These data are often large, multi-dimensional, and subject to differing conventions for data structures, file formats, coordinate spaces, and units of measure. When visualized, these data require differing, and sometimes conflicting, conventions for visual representations, dimensionality, symbology, and interaction. All of this makes the visualization of integrated Earth science data particularly difficult. The OpenEarth Framework (OEF) is an open-source data integration and visualization suite of applications and libraries being developed by the GEON project at the University of California, San Diego, USA. Funded by the NSF, the project is leveraging virtual globe technology from NASA's WorldWind to create interactive 3D visualization tools that combine and layer data from a wide variety of sources to create a holistic view of features at, above, and beneath the Earth's surface. The OEF architecture is open, cross-platform, modular, and based upon Java. The OEF's modular approach to software architecture yields an array of mix-and-match software components for assembling custom applications. Available modules support file format handling, web service communications, data management, user interaction, and 3D visualization. File parsers handle a variety of formal and de facto standard file formats used in the field. Each one imports data into a general-purpose common data model supporting multidimensional regular and irregular grids, topography, feature geometry, and more. Data within these data models may be manipulated, combined, reprojected, and visualized. The OEF's visualization features support a variety of conventional and new visualization techniques for looking at topography, tomography, point clouds, imagery, maps, and feature geometry. 3D data such as seismic tomography may be sliced by multiple oriented cutting planes and isosurfaced to create 3D skins that trace feature boundaries within the data. Topography may be overlaid with satellite imagery, maps, and data such as gravity and magnetics measurements. Multiple data sets may be visualized simultaneously using overlapping layers within a common 3D coordinate space. Data management within the OEF handles and hides the inevitable quirks of differing file formats, web protocols, storage structures, coordinate spaces, and metadata representations. Heuristics are used to extract necessary metadata used to guide data and visual operations. Derived data representations are computed to better support fluid interaction and visualization while the original data is left unchanged in its original form. Data is cached for better memory and network efficiency, and all visualization makes use of 3D graphics hardware support found on today's computers. The OpenEarth Framework project is currently prototyping the software for use in the visualization, and integration of continental scale geophysical data being produced by EarthScope-related research in the Western US. The OEF is providing researchers with new ways to display and interrogate their data and is anticipated to be a valuable tool for future EarthScope-related research.

Using Semantic Web technologies for the generation of domain-specific templates to support clinical study metadata standards.

PubMed

Jiang, Guoqian; Evans, Julie; Endle, Cory M; Solbrig, Harold R; Chute, Christopher G

2016-01-01

The Biomedical Research Integrated Domain Group (BRIDG) model is a formal domain analysis model for protocol-driven biomedical research, and serves as a semantic foundation for application and message development in the standards developing organizations (SDOs). The increasing sophistication and complexity of the BRIDG model requires new approaches to the management and utilization of the underlying semantics to harmonize domain-specific standards. The objective of this study is to develop and evaluate a Semantic Web-based approach that integrates the BRIDG model with ISO 21090 data types to generate domain-specific templates to support clinical study metadata standards development. We developed a template generation and visualization system based on an open source Resource Description Framework (RDF) store backend, a SmartGWT-based web user interface, and a "mind map" based tool for the visualization of generated domain-specific templates. We also developed a RESTful Web Service informed by the Clinical Information Modeling Initiative (CIMI) reference model for access to the generated domain-specific templates. A preliminary usability study is performed and all reviewers (n = 3) had very positive responses for the evaluation questions in terms of the usability and the capability of meeting the system requirements (with the average score of 4.6). Semantic Web technologies provide a scalable infrastructure and have great potential to enable computable semantic interoperability of models in the intersection of health care and clinical research.

Geometric parameter analysis to predetermine optimal radiosurgery technique for the treatment of arteriovenous malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mestrovic, Ante; Clark, Brenda G.; Department of Medical Physics, British Columbia Cancer Agency, Vancouver, British Columbia

2005-11-01

Purpose: To develop a method of predicting the values of dose distribution parameters of different radiosurgery techniques for treatment of arteriovenous malformation (AVM) based on internal geometric parameters. Methods and Materials: For each of 18 previously treated AVM patients, four treatment plans were created: circular collimator arcs, dynamic conformal arcs, fixed conformal fields, and intensity-modulated radiosurgery. An algorithm was developed to characterize the target and critical structure shape complexity and the position of the critical structures with respect to the target. Multiple regression was employed to establish the correlation between the internal geometric parameters and the dose distribution for differentmore » treatment techniques. The results from the model were applied to predict the dosimetric outcomes of different radiosurgery techniques and select the optimal radiosurgery technique for a number of AVM patients. Results: Several internal geometric parameters showing statistically significant correlation (p < 0.05) with the treatment planning results for each technique were identified. The target volume and the average minimum distance between the target and the critical structures were the most effective predictors for normal tissue dose distribution. The structure overlap volume with the target and the mean distance between the target and the critical structure were the most effective predictors for critical structure dose distribution. The predicted values of dose distribution parameters of different radiosurgery techniques were in close agreement with the original data. Conclusions: A statistical model has been described that successfully predicts the values of dose distribution parameters of different radiosurgery techniques and may be used to predetermine the optimal technique on a patient-to-patient basis.« less

Double Coaxial Microcatheter Technique for Glue Embolization of Renal Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uchikawa, Yoko, E-mail: jauchikawa@gmail.com; Mori, Kensaku, E-mail: moriken@md.tsukuba.ac.jp; Shiigai, Masanari, E-mail: m-41gai@yahoo.co.jp

PurposeTo demonstrate the technical benefit of the double coaxial microcatheter technique for embolization of renal arteriovenous malformations (AVMs) with n-butyl cyanoacrylate and iodized oil (glue).Materials and MethodsSix consecutive patients (1 man and 5 women; mean age 61 years; range 44–77 years) with renal AVMs were included. Five patients had hematuria, and one had a risk of heart failure due to a large intrarenal arteriovenous shunt. All patients underwent transarterial embolization using glue and the double coaxial microcatheter technique with outer 2.6F and inner 1.9F microcatheters. After glue injection, the inner microcatheter was retracted, while the outer microcatheter was retained. We assessed themore » complications and clinical outcomes of this technique.ResultsTechnical success was achieved in all patients. In 9 sessions, 34 feeding arteries were embolized with glue using the double coaxial microcatheter technique, 1 was embolized with glue using a single microcatheter, and 2 were embolized with coils. The double coaxial microcatheter technique was useful for selecting small tortuous feeding arteries, preventing glue reflux to the proximal arteries, and approaching multiple feeding arteries without complete retraction of the microcatheters. As a minor complication, glue migrated into the venous system in four patients without any sequelae. In all patients, favorable clinical outcomes, including hematuria cessation in five patients and improvement of the large intrarenal arteriovenous shunt in one patient, were obtained without deterioration of renal function.ConclusionGlue embolization with the double coaxial microcatheter technique was useful for treating renal AVMs with multiple tortuous feeding arteries.« less

Retrospective analysis of imaging techniques for treatment planning and monitoring of obliteration for gamma knife treatment of cerebral arteriovenous malformation.

PubMed

Amponsah, Kwame; Ellis, Thomas L; Chan, Michael D; Lovato, James F; Bourland, J Daniel; deGuzman, Allan F; Ekstrand, Kenneth E; Munley, Michael T; McMullen, Kevin P; Shaw, Edward G; Tatter, Stephen B

2012-10-01

It has been well established that Gamma Knife radiosurgery (GKS) is an effective treatment for brain arteriovenous malformations (AVMs). To evaluate complete obliteration rates for magnetic resonance imaging (MRI)-based GKS treatment planning performed with and without angiography and to conduct a preliminary assessment of the utility of using pulsed arterial spin labeling (PASL) magnetic resonance (MR) perfusion imaging to confirm complete obliteration. Forty-six patients were identified who had undergone GKS without embolization with a minimum follow-up of 2 years. One group was planned with integrated stereotactic angiography and MR (spoiled gradient recalled) images obtained on the day of GKS. A second technique avoided the risk of arteriography by using only axial MR images. Beginning in 2007, PASL MR perfusion imaging was routinely performed as a portion of the follow-up MRI to assess the restoration of normal blood flow of the nidus and surrounding area. The overall obliteration rate for the angiography/MRI group was 88.0% (29 of 33). Patients in the MRI-only group had an obliteration rate of 61.5% (8 of 13), with P=.092 with the Fisher exact test, which is not statistically significant. A Kaplan-Meier analysis was also not statistically significant (log rank test, P=.474). Four of 9 patients with incomplete obliteration on angiography also had shown residual abnormal blood flow on PASL imaging. This retrospective analysis shows that treatment planning technique used in GKS does not play a role in the eventual obliteration of treated AVMs. PASL may have potential in the evaluation of AVM obliteration.

Tool-Tissue Interaction Forces in Brain Arteriovenous Malformation Surgery.

PubMed

Sugiyama, Taku; Gan, Liu Shi; Zareinia, Kourosh; Lama, Sanju; Sutherland, Garnette R

2017-06-01

Surgical resection of a brain arteriovenous malformation (AVM) poses a technical challenge because of the fragility and number of small feeding and draining vessels around the nidus. Acquiring knowledge of the optimal force applied to such tissue is important in surgical performance and education. A force-sensing bipolar forceps was developed through installation of strain gauge sensors, and force profiles were obtained from 2 AVM surgeries. The force data associated with vessel injury, unsuccessful trial, was compared with that from successful trials. Receiver operating curve analysis was used for determining optimal force threshold and evaluating the discriminative accuracy of measurement. Force data from 519 trials was collected, of which 16 (3.1%) were unsuccessful. The mean and maximum forces in successful trials were 0.23 ± 0.06 N and 0.35 ± 0.11 N compared with unsuccessful trials of 0.33 ± 0.05 N and 0.53 ± 0.11 N, respectively (P < 0.001). There was a strong association of mean and maximum force peaks with unsuccessful trials as reflected by the area under the curve of 0.91 and 0.87, respectively. Threshold analysis showed that the rate of unsuccessful trials and error forces tended to increase with surgical time. Excessive force at the tool tip may result in injury to fragile vessels during AVM surgery. A quantifiable metric through force sensing instruments can detect and predict the occurrence of such injury. Such an instrument may be ideal for resident training and evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

Surgical planning for microsurgical excision of cerebral arterio-venous malformations using virtual reality technology.

PubMed

Ng, Ivan; Hwang, Peter Y K; Kumar, Dinesh; Lee, Cheng Kiang; Kockro, Ralf A; Sitoh, Y Y

2009-05-01

To evaluate the feasibility of surgical planning using a virtual reality platform workstation in the treatment of cerebral arterio-venous malformations (AVMs) Patient-specific data of multiple imaging modalities were co-registered, fused and displayed as a 3D stereoscopic object on the Dextroscope, a virtual reality surgical planning platform. This system allows for manipulation of 3D data and for the user to evaluate and appreciate the angio-architecture of the nidus with regards to position and spatial relationships of critical feeders and draining veins. We evaluated the ability of the Dextroscope to influence surgical planning by providing a better understanding of the angio-architecture as well as its impact on the surgeon's pre- and intra-operative confidence and ability to tackle these lesions. Twenty four patients were studied. The mean age was 29.65 years. Following pre-surgical planning on the Dextroscope, 23 patients underwent microsurgical resection after pre-surgical virtual reality planning, during which all had documented complete resection of the AVM. Planning on the virtual reality platform allowed for identification of critical feeders and draining vessels in all patients. The appreciation of the complex patient specific angio-architecture to establish a surgical plan was found to be invaluable in the conduct of the procedure and was found to enhance the surgeon's confidence significantly. Surgical planning of resection of an AVM with a virtual reality system allowed detailed and comprehensive analysis of 3D multi-modality imaging data and, in our experience, proved very helpful in establishing a good surgical strategy, enhancing intra-operative spatial orientation and increasing surgeon's confidence.

Results of Surgery for Low-Grade Brain Arteriovenous Malformation Resection by Early Career Neurosurgeons: An Observational Study.

PubMed

Patel, Nirav J; Bervini, David; Eftekhar, Behzad; Davidson, Andrew Stewart; Walsh, Daniel C; Assaad, Nazih N; Morgan, Michael Kerin

2018-03-28

For sustainability of arteriovenous malformation (AVM) surgery, results from early career cerebrovascular neurosurgeons (ECCNs) must be acceptably safe. To determine whether ECCNs performance of Spetzler-Ponce Class A AVM (SPC A) resection can be acceptably safe. ECCNs completing a cerebrovascular fellowship (2004-2015) with the last author were included. Inclusion of the ECCN cases occurred if they: had a prospective database of all AVM cases since commencing independent practice; were the primary surgeon on SPC A; and had made the significant management decisions. All SPC A surgical cases from the beginning of the ECCN's independent surgical practice to a maximum of 8 yr were included. An adverse outcome was considered a complication of surgery leading to a new permanent neurological deficit with a last modified Rankin Scale score >1. A cumulative summation (Cusum) plot examined the performance of each surgery. The highest acceptable level of adverse outcomes for the Cusum was 3.3%, derived from the upper 95% confidence interval of the last author's reported series. Six ECCNs contributed 110 cases for analysis. The median number of SPC A cases operated by each ECCN was 16.5 (range 4-40). Preoperative embolization was performed in 5 (4.5%). The incidence of adverse outcomes was 1.8% (95% confidence interval: <0.01%-6.8%). At no point during the accumulated series did the combined cohort become unacceptable by the Cusum plot. ECCNs with appropriate training appointed to large-volume cerebrovascular centers can achieve results for surgery for SPC A that are not appreciably worse than those published from high-volume neurosurgeons.

Post procedure headache in patients treated for neurovascular arteriovenous malformations and aneurysms using endovascular therapy.

PubMed

Khan, Sabrina; Amin, Faisal Mohammad; Hauerberg, John; Holtmannspötter, Markus; Petersen, Julie Falkenberg; Fakhril-Din, Zainab; Gaist, David; Ashina, Messoud

2016-12-01

Though endovascular therapy (EVT) is increasingly applied in the treatment of intracranial vascular lesions, little is known about the effect of EVT on post-procedure headache. We aimed to investigate the prevalence of headache in patients who have undergone EVT for cerebral arteriovenous malformations (AVMs) and aneurysms. A total of 324 patients underwent EVT treatment for aneurysms and AVMs at the Danish National Hospital from January 2012 to December 2014. We applied strict exclusion criteria in order to minimize the effect of other factors on headache occurrence, e.g., craniotomy. Eligible subjects were phone-interviewed using a purpose-developed semi-structured questionnaire. Headaches were classified according to ICHD-III beta criteria. The 59 patients underwent treatment of aneurysms (n = 43), cranial dural fistulas (n = 11), and AVMs (n = 5). There was a significant increase in overall headache (p = 0.017) and tension-type headache (TTH) (p = 0.012) within the first 3 months after EVT compared to 1 month before EVT. However, at interview time (median 2.5 years post-EVT), the increase in overall headache, migraine, and tension-type headache was not statistically significant. A minority of patients experienced headaches for the first time within 3 months of their EVT (migraine 4, TTH 10). At interview time, 50 % of these new headaches still persisted. Our results suggest a temporary increase in headache in the first 3 months after EVT, which normalizes over time. Clinicians may use this knowledge to better inform their patients of functional outcomes after their EVT procedure.

Interdisciplinary Clinical Management of High Grade Arteriovenous Malformations and Ruptured Flow-Related Aneurysms in the Posterior Fossa

PubMed Central

Mpotsaris, A.; Loehr, C.; Harati, A.; Lohmann, F.; Puchner, M.; Weber, W.

2010-01-01

Summary Posterior fossa arteriovenous malformations are rare entities and treatment modalities technically challenging. In recent years new therapeutic options have emerged through microsurgical and endovascular means. Based on a series of six cases we describe combined interdisciplinary treatment strategies and report the outcome in a midterm follow-up interval of 12 months. Clinical case data were collected during acute phase and follow-up including standardized angiographic control intervals during follow-up and assessment of the outcome. Treatment options included endovascular techniques as well as microsurgical techniques. All reported cases had SAH based on ruptured flow-related aneurysms in posterior fossa AVM; three out of six had multiple aneurysms. In one case we observed a de novo formation of two flow-associated distal aneurysms in an interval of ten years. Two patients were treated only endovascularly, one patient only surgically and three patients with combined methods. Five out of six patients had a good outcome (GOS 4 or 5). One died in the acute phase. Infratentorial AVMs are rare but characterized by a high risk of rupture and SAH, especially in conjunction with flow related aneurysms, which are predictors of poor outcome. The anatomic conditions of the posterior fossa may lead quickly to life-threatening complications due to mass effects. The present study indicates that treatment strategies in the acute phase should focus on flow-related aneurysms, followed by an elective AVM embolization and ectomy whenever possible. An experienced interdisciplinary team and the combination of techniques contribute to a reduction of complications and to a better outcome. PMID:21162770

Fast processing of digital imaging and communications in medicine (DICOM) metadata using multiseries DICOM format.

PubMed

Ismail, Mahmoud; Philbin, James

2015-04-01

The digital imaging and communications in medicine (DICOM) information model combines pixel data and its metadata in a single object. There are user scenarios that only need metadata manipulation, such as deidentification and study migration. Most picture archiving and communication system use a database to store and update the metadata rather than updating the raw DICOM files themselves. The multiseries DICOM (MSD) format separates metadata from pixel data and eliminates duplicate attributes. This work promotes storing DICOM studies in MSD format to reduce the metadata processing time. A set of experiments are performed that update the metadata of a set of DICOM studies for deidentification and migration. The studies are stored in both the traditional single frame DICOM (SFD) format and the MSD format. The results show that it is faster to update studies' metadata in MSD format than in SFD format because the bulk data is separated in MSD and is not retrieved from the storage system. In addition, it is space efficient to store the deidentified studies in MSD format as it shares the same bulk data object with the original study. In summary, separation of metadata from pixel data using the MSD format provides fast metadata access and speeds up applications that process only the metadata.

Transforming Dermatologic Imaging for the Digital Era: Metadata and Standards.

PubMed

Caffery, Liam J; Clunie, David; Curiel-Lewandrowski, Clara; Malvehy, Josep; Soyer, H Peter; Halpern, Allan C

2018-01-17

Imaging is increasingly being used in dermatology for documentation, diagnosis, and management of cutaneous disease. The lack of standards for dermatologic imaging is an impediment to clinical uptake. Standardization can occur in image acquisition, terminology, interoperability, and metadata. This paper presents the International Skin Imaging Collaboration position on standardization of metadata for dermatologic imaging. Metadata is essential to ensure that dermatologic images are properly managed and interpreted. There are two standards-based approaches to recording and storing metadata in dermatologic imaging. The first uses standard consumer image file formats, and the second is the file format and metadata model developed for the Digital Imaging and Communication in Medicine (DICOM) standard. DICOM would appear to provide an advantage over using consumer image file formats for metadata as it includes all the patient, study, and technical metadata necessary to use images clinically. Whereas, consumer image file formats only include technical metadata and need to be used in conjunction with another actor-for example, an electronic medical record-to supply the patient and study metadata. The use of DICOM may have some ancillary benefits in dermatologic imaging including leveraging DICOM network and workflow services, interoperability of images and metadata, leveraging existing enterprise imaging infrastructure, greater patient safety, and better compliance to legislative requirements for image retention.

Fast processing of digital imaging and communications in medicine (DICOM) metadata using multiseries DICOM format

PubMed Central

Ismail, Mahmoud; Philbin, James

2015-01-01

Abstract. The digital imaging and communications in medicine (DICOM) information model combines pixel data and its metadata in a single object. There are user scenarios that only need metadata manipulation, such as deidentification and study migration. Most picture archiving and communication system use a database to store and update the metadata rather than updating the raw DICOM files themselves. The multiseries DICOM (MSD) format separates metadata from pixel data and eliminates duplicate attributes. This work promotes storing DICOM studies in MSD format to reduce the metadata processing time. A set of experiments are performed that update the metadata of a set of DICOM studies for deidentification and migration. The studies are stored in both the traditional single frame DICOM (SFD) format and the MSD format. The results show that it is faster to update studies’ metadata in MSD format than in SFD format because the bulk data is separated in MSD and is not retrieved from the storage system. In addition, it is space efficient to store the deidentified studies in MSD format as it shares the same bulk data object with the original study. In summary, separation of metadata from pixel data using the MSD format provides fast metadata access and speeds up applications that process only the metadata. PMID:26158117

ISO, FGDC, DIF and Dublin Core - Making Sense of Metadata Standards for Earth Science Data

NASA Astrophysics Data System (ADS)

Jones, P. R.; Ritchey, N. A.; Peng, G.; Toner, V. A.; Brown, H.

2014-12-01

Metadata standards provide common definitions of metadata fields for information exchange across user communities. Despite the broad adoption of metadata standards for Earth science data, there are still heterogeneous and incompatible representations of information due to differences between the many standards in use and how each standard is applied. Federal agencies are required to manage and publish metadata in different metadata standards and formats for various data catalogs. In 2014, the NOAA National Climatic data Center (NCDC) managed metadata for its scientific datasets in ISO 19115-2 in XML, GCMD Directory Interchange Format (DIF) in XML, DataCite Schema in XML, Dublin Core in XML, and Data Catalog Vocabulary (DCAT) in JSON, with more standards and profiles of standards planned. Of these standards, the ISO 19115-series metadata is the most complete and feature-rich, and for this reason it is used by NCDC as the source for the other metadata standards. We will discuss the capabilities of metadata standards and how these standards are being implemented to document datasets. Successful implementations include developing translations and displays using XSLTs, creating links to related data and resources, documenting dataset lineage, and establishing best practices. Benefits, gaps, and challenges will be highlighted with suggestions for improved approaches to metadata storage and maintenance.