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Sample records for 1-year repeat mri

  1. Automated mapping of hippocampal atrophy in 1-year repeat MRI data from 490 subjects with Alzheimer’s disease, mild cognitive impairment, and elderly controls

    PubMed Central

    Morra, Jonathan H.; Tu, Zhuowen; Apostolova, Liana G.; Green, Amity E.; Avedissian, Christina; Madsen, Sarah K.; Parikshak, Neelroop; Toga, Arthur W.; Jack, Clifford R.; Schuff, Norbert; Weiner, Michael W.; Thompson, Paul M.

    2009-01-01

    As one of the earliest structures to degenerate in Alzheimer’s disease (AD), the hippocampus is the target of many studies of factors that influence rates of brain degeneration in the elderly. In one of the largest brain mapping studies to date, we mapped the 3D profile of hippocampal degeneration over time in 490 subjects scanned twice with brain MRI over a 1-year interval (980 scans). We examined baseline and 1-year follow-up scans of 97 AD subjects (49 males/48 females), 148 healthy control subjects (75 males/73 females), and 245 subjects with mild cognitive impairment (MCI; 160 males/85 females). We used our previously validated automated segmentation method, based on AdaBoost, to create 3D hippocampal surface models in all 980 scans. Hippocampal volume loss rates increased with worsening diagnosis (normal=0.66%/year; MCI=3.12%/year; AD=5.59%/year), and correlated with both baseline and interval changes in Mini-Mental State Examination (MMSE) scores and global and sum-of-boxes Clinical Dementia Rating scale (CDR) scores. Surface-based statistical maps visualized a selective profile of ongoing atrophy in all three diagnostic groups. Healthy controls carrying the ApoE4 gene atrophied faster than non-carriers, while more educated controls atrophied more slowly; converters from MCI to AD showed faster atrophy than non-converters. Hippocampal loss rates can be rapidly mapped, and they track cognitive decline closely enough to be used as surrogate markers of Alzheimer’s disease in drug trials. They also reveal genetically greater atrophy in cognitively intact subjects. PMID:19041724

  2. MRI as outcome measure in facioscapulohumeral muscular dystrophy: 1-year follow-up of 45 patients.

    PubMed

    Andersen, Grete; Dahlqvist, Julia R; Vissing, Christoffer R; Heje, Karen; Thomsen, Carsten; Vissing, John

    2017-03-01

    There is no effective treatment available for facioscapulohumeral muscular dystrophy type 1 (FSHD1), but emerging therapies are under way that call for a better understanding of natural history in this condition. In this prospective, longitudinal study, we used quantitative MRI to assess yearly disease progression in patients with FSHD1. Ambulatory patients with confirmed diagnosis of FSHD1 (25/20 men/women, age 20-75 years, FSHD score: 0-12) were tested with 359-560-day interval between tests. Using the MRI Dixon technique, muscle fat replacement was evaluated in paraspinal, thigh, and calf muscles. Changes were compared with those in FSHD score, muscle strength (hand-held dynamometry), 6-minute-walk-distance, 14-step-stair-test, and 5-time-sit-to-stand-test. Composite absolute fat fraction of all assessed muscles increased by 0.036 (CI 0.026-0.046, P < 0.001), with increases in all measured muscle groups. The clinical severity FSHD score worsened (10%, P < 0.05), muscle strength decreased over the hip (8%), neck (8%), and back (17%) (P < 0.05), but other strength measures, 6-minute-walk-distance, 5-times-sit-to-stand-test, and 14-step-stair-test were unchanged. Changes in muscle strength, FSHD score, and fat fraction did not correlate. This first study to systemically monitor quantitative fat replacement longitudinally in FSHD1 shows that MRI provides an objective measure of disease progression, often before changes can be appreciated in strength and functional tests. The study indicates that quantitative MRI can be a helpful end-point in follow-up and therapeutic trials of patients with FSHD1.

  3. Within- and Between-Child Variation in Repeated Urinary Pesticide Metabolite Measurements over a 1-Year Period

    PubMed Central

    Hughes, Michael D.; Spengler, John D.; Lu, Chensheng

    2013-01-01

    Background: Children are exposed to pesticides from many sources and routes, including dietary and incidental ingestion, dermal absorption, and inhalation. Linking health outcomes to these exposures using urinary metabolites requires understanding temporal variability within subjects to avoid exposure misclassification. Objectives: We characterized the within- and between-child variability of urinary organophosphorus and pyrethroid metabolites in 23 participants of the Children’s Pesticide Exposure Study–Washington over 1 year and examined the ability of one to four spot urine samples to categorize mean exposures. Methods: Each child provided urine samples twice daily over 7- to 16-day sessions in four seasons in 2003 and 2004. Samples were analyzed for five pyrethroid and five organophosphorus (OP) metabolites. After adjusting for specific gravity, we used a customized maximum likelihood estimation linear mixed-effects model that accounted for values below the limit of detection to calculate intraclass correlation coefficients (ICC) and conducted surrogate category analyses. Results: Within-child variability was 2–11 times greater than between-child variability. When restricted to samples collected during a single season, ICCs were higher in the fall, winter, and spring than in summer for OPs, and higher in summer and winter for pyrethroids, indicating an increase in between-person variability relative to within-person variability during these seasons. Surrogate category analyses demonstrated that a single spot urine sample did not categorize metabolite concentrations well, and that four or more samples would be needed to categorize children into quartiles consistently. Conclusions: Urinary biomarkers of these short half-life pesticides exhibited substantial within-person variability in children observed over four seasons. Researchers investigating pesticides and health outcomes in children may need repeated biomarker measurements to derive accurate

  4. Are early MRI findings correlated with long-lasting symptoms following whiplash injury? A prospective trial with 1-year follow-up

    PubMed Central

    Sorensen, Joan S.; Andersen, Hans; Keseler, Bjarne; Jensen, Troels S.; Bendix, Tom

    2008-01-01

    Neck pain is the cardinal symptom following whiplash injuries. The trauma mechanism could theoretically lead to both soft tissue and bone injury that could be visualised by means of MRI. From previous quite small trials it seems that MRI does not demonstrate significant tissue damage. Large prospectively followed cohorts are needed to identify possible clinically relevant MRI findings. The objective of this trial was to evaluate (1) the predictive value of cervical MRI after whiplash injuries and (2) the value of repeating MRI examinations after 3 months including sequences with flexion and extension of the cervical spine. Participants were included after rear-end or frontal car collisions. Patients with fractures or dislocations diagnosed by standard procedures at the emergency unit were not included. MRI scans of the cervical spine were performed at baseline and repeated after 3 months. Clinical follow-ups were performed after 3 and 12 months. Outcome parameters were neck pain, headache, neck disability and working ability. A total of 178 participants had a cervical MRI scan on average 13 days after the injury. Traumatic findings were observed in seven participants. Signs of disc degeneration were common and most frequent at the C5–6 and C6–7 levels. Findings were not associated with outcome after 3 or 12 months. The population had no considerable neck trouble prior to the whiplash injury and the non-traumatic findings represent findings to be expected in the background population. Trauma-related MRI findings are rare in a whiplash population screened for serious injuries in the emergency unit and not related to a specific symptomatology. Also, pre-existing degeneration is not associated with prognosis. PMID:18512085

  5. Repeatability of Cerebral Perfusion Using Dynamic Susceptibility Contrast MRI in Glioblastoma Patients12

    PubMed Central

    Jafari-Khouzani, Kourosh; Emblem, Kyrre E.; Kalpathy-Cramer, Jayashree; Bjørnerud, Atle; Vangel, Mark G.; Gerstner, Elizabeth R.; Schmainda, Kathleen M.; Paynabar, Kamran; Wu, Ona; Wen, Patrick Y.; Batchelor, Tracy; Rosen, Bruce; Stufflebeam, Steven M.

    2015-01-01

    OBJECTIVES This study evaluates the repeatability of brain perfusion using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a variety of post-processing methods. METHODS Thirty-two patients with newly diagnosed glioblastoma were recruited. On a 3-T MRI using a dual-echo, gradient-echo spin-echo DSC-MRI protocol, the patients were scanned twice 1 to 5 days apart. Perfusion maps including cerebral blood volume (CBV) and cerebral blood flow (CBF) were generated using two contrast agent leakage correction methods, along with testing normalization to reference tissue, and application of arterial input function (AIF). Repeatability of CBV and CBF within tumor regions and healthy tissues, identified by structural images, was assessed with intra-class correlation coefficients (ICCs) and repeatability coefficients (RCs). Coefficients of variation (CVs) were reported for selected methods. RESULTS CBV and CBF were highly repeatable within tumor with ICC values up to 0.97. However, both CBV and CBF showed lower ICCs for healthy cortical tissues (up to 0.83), healthy gray matter (up to 0.95), and healthy white matter (WM; up to 0.93). The values of CV ranged from 6% to 10% in tumor and 3% to 11% in healthy tissues. The values of RC relative to the mean value of measurement within healthy WM ranged from 22% to 42% in tumor and 7% to 43% in healthy tissues. These percentages show how much variation in perfusion parameter, relative to that in healthy WM, we expect to observe to consider it statistically significant. We also found that normalization improved repeatability, but AIF deconvolution did not. CONCLUSIONS DSC-MRI is highly repeatable in high-grade glioma patients. PMID:26055170

  6. Reproducibility of Brain Morphometry from Short-Term Repeat Clinical MRI Examinations: A Retrospective Study

    PubMed Central

    Liu, Hon-Man; Chen, Shan-Kai; Chen, Ya-Fang; Lee, Chung-Wei; Yeh, Lee-Ren

    2016-01-01

    Purpose To assess the inter session reproducibility of automatic segmented MRI-derived measures by FreeSurfer in a group of subjects with normal-appearing MR images. Materials and Methods After retrospectively reviewing a brain MRI database from our institute consisting of 14,758 adults, those subjects who had repeat scans and had no history of neurodegenerative disorders were selected for morphometry analysis using FreeSurfer. A total of 34 subjects were grouped by MRI scanner model. After automatic segmentation using FreeSurfer, label-wise comparison (involving area, thickness, and volume) was performed on all segmented results. An intraclass correlation coefficient was used to estimate the agreement between sessions. Wilcoxon signed rank test was used to assess the population mean rank differences across sessions. Mean-difference analysis was used to evaluate the difference intervals across scanners. Absolute percent difference was used to estimate the reproducibility errors across the MRI models. Kruskal-Wallis test was used to determine the across-scanner effect. Results The agreement in segmentation results for area, volume, and thickness measurements of all segmented anatomical labels was generally higher in Signa Excite and Verio models when compared with Sonata and TrioTim models. There were significant rank differences found across sessions in some labels of different measures. Smaller difference intervals in global volume measurements were noted on images acquired by Signa Excite and Verio models. For some brain regions, significant MRI model effects were observed on certain segmentation results. Conclusions Short-term scan-rescan reliability of automatic brain MRI morphometry is feasible in the clinical setting. However, since repeatability of software performance is contingent on the reproducibility of the scanner performance, the scanner performance must be calibrated before conducting such studies or before using such software for retrospective

  7. Repeated dexamphetamine treatment alters the dopaminergic system and increases the phMRI response to methylphenidate

    PubMed Central

    Schrantee, Anouk; Tremoleda, Jordi L.; Wylezinska-Arridge, Marzena; Bouet, Valentine; Hesseling, Peter; Meerhoff, Gideon F.; de Bruin, Kora M.; Koeleman, Jan; Freret, Thomas; Boulouard, Michel; Desfosses, Emilie; Galineau, Laurent; Gozzi, Alessandro; Dauphin, François; Gsell, Willy; Booij, Jan; Lucassen, Paul J.; Reneman, Liesbeth

    2017-01-01

    Dexamphetamine (AMPH) is a psychostimulant drug that is used both recreationally and as medication for attention deficit hyperactivity disorder. Preclinical studies have demonstrated that repeated exposure to AMPH can induce damage to nerve terminals of dopamine (DA) neurons. We here assessed the underlying neurobiological changes in the DA system following repeated AMPH exposure and pre-treated rats with AMPH or saline (4 times 5 mg/kg s.c., 2 hours apart), followed by a 1-week washout period. We then used pharmacological MRI (phMRI) with a methylphenidate (MPH) challenge, as a sensitive and non-invasive in-vivo measure of DAergic function. We subsequently validated the DA-ergic changes post-mortem, using a.o. high-performance liquid chromatography (HPLC) and autoradiography. In the AMPH pre-treated group, we observed a significantly larger BOLD response to the MPH challenge, particularly in DA-ergic brain areas and their downstream projections. Subsequent autoradiography studies showed that AMPH pre-treatment significantly reduced DA transporter (DAT) density in the caudate-putamen (CPu) and nucleus accumbens, whereas HPLC analysis revealed increases in the DA metabolite homovanillic acid in the CPu. Our results suggest that AMPH pre-treatment alters DAergic responsivity, a change that can be detected with phMRI in rats. These phMRI changes likely reflect increased DA release together with reduced DAT binding. The ability to assess subtle synaptic changes using phMRI is promising for both preclinical studies of drug discovery, and for clinical studies where phMRI can be a useful tool to non-invasively investigate DA abnormalities, e.g. in neuropsychiatric disorders. PMID:28241065

  8. Repeated BOLD-fMRI Imaging of Deep Brain Stimulation Responses in Rats

    PubMed Central

    Chao, Tzu-Hao Harry; Chen, Jyh-Horng; Yen, Chen-Tung

    2014-01-01

    Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI. PMID:24825464

  9. Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy.

    PubMed

    Cheikh, Alexandre Ben; Girouin, Nicolas; Colombel, Marc; Maréchal, Jean-Marie; Gelet, Albert; Bissery, Alvine; Rabilloud, Muriel; Lyonnet, Denis; Rouvière, Olivier

    2009-03-01

    We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.

  10. Reliability of Early Magnetic Resonance Imaging (MRI) and Necessity of Repeating MRI in Noncooled and Cooled Infants With Neonatal Encephalopathy.

    PubMed

    Chakkarapani, Elavazhagan; Poskitt, Kenneth J; Miller, Steven P; Zwicker, Jill G; Xu, Qi; Wong, Darren S T; Roland, Elke H; Hill, Alan; Chau, Vann

    2016-04-01

    In cooled newborns with encephalopathy, although late magnetic resonance imaging (MRI) scan (10-14 days of age) is reliable in predicting long-term outcome, it is unknown whether early scan (3-6 days of life) is. We compared the predominant pattern and extent of lesion between early and late MRI in 89 term neonates with neonatal encephalopathy. Forty-three neonates (48%) were cooled. The predominant pattern of lesions and the extent of lesion in the watershed region agreed near perfectly in noncooled (kappa = 0.94; k = 0.88) and cooled (k = 0.89; k = 0.87) infants respectively. There was perfect agreement in the extent of lesion in the basal nuclei in noncooled infants (k = 0.83) and excellent agreement in cooled infants (k = 0.67). Changes in extent of lesions on late MRI occurred in 19 of 89 infants, with higher risk in infants with hypoglycemia and moderate-severe lesions in basal nuclei. In most term neonates with neonatal encephalopathy, early MRI (relative to late scan) robustly predicts the predominant pattern and extent of injury.

  11. Low Compliance in a Health-Conscience Spending Era Likely Helps Obviates the Need for 6 month BI-RADS 3 Breast MRI Follow-up After 1 year.

    PubMed

    Mosier, Andrew; Gupta, Esha; Ataya, Dana; Bhatt, Kavita; Rim, Alice

    2017-03-01

    The goal of our IRB-approved study was to assess if a follow-up MRI every 6 months for 2 years is the most appropriate short-interval follow-up schedule. 203 breast MRI exams were performed from October 2009 to January 2014 as part of a BI-RADS 3 follow-up representing 2.6% of all breast MRIs (7,822) performed. We performed a retrospective longitudinal medical records review of compliance; malignancy rate of BI-RADS 3 exams; and average time and number of breast MRIs necessary prior to definitive disposition. While 77.8% eventually returned, only 45.5% of patients were compliant with follow-up at or near 6 months (4.5-7.5 months). Of those who eventually returned, it took an average of 1.31 follow-up MRIs (95% CI: 1.20-1.43 exams) and 10.3 months (95% CI: 9.0-11.7 months) before definitive disposition. 93.5% of initial findings were dispositioned as benign after two follow-up MRI exams (malignancy rate: 0.98%). Our results lend support to the possibility that the follow-up interval for BI-RADS 3 breast MRIs could be lengthened to 12 months if additional follow-up MRIs are necessary after the first year of 6-month follow-up breast MRIs. Foremost, this appears to be a safe follow-up alternative since benign definitive disposition can usually be made in less than 1 year. Supplemental reasons include persistent low-patient compliance (as redemonstrated in our study) and the higher cost of breast MRI compared to mammogram/ultrasound follow-up. Finally, this paper's findings further support the suggested MRI follow-up interval in the newest BI-RADS atlas.

  12. Repeated diffusion MRI reveals earliest time point for stratification of radiotherapy response in brain metastases

    NASA Astrophysics Data System (ADS)

    Mahmood, Faisal; Johannesen, Helle H.; Geertsen, Poul; Hansen, Rasmus H.

    2017-04-01

    An imaging biomarker for early prediction of treatment response potentially provides a non-invasive tool for better prognostics and individualized management of the disease. Radiotherapy (RT) response is generally related to changes in gross tumor volume manifesting months later. In this prospective study we investigated the apparent diffusion coefficient (ADC), perfusion fraction and pseudo diffusion coefficient derived from diffusion weighted MRI as potential early biomarkers for radiotherapy response of brain metastases. It was a particular aim to assess the optimal time point for acquiring the DW-MRI scan during the course of treatment, since to our knowledge this important question has not been addressed directly in previous studies. Twenty-nine metastases (N  =  29) from twenty-one patients, treated with whole-brain fractionated external beam RT were analyzed. Patients were scanned with a 1 T MRI system to acquire DW-, T2*W-, T2W- and T1W scans, before start of RT, at each fraction and at follow up two to three months after RT. The DW-MRI parameters were derived using regions of interest based on high b-value images (b  =  800 s mm‑2). Both volumetric and RECIST criteria were applied for response evaluation. It was found that in non-responding metastases the mean ADC decreased and in responding metastases it increased. The volume based response proved to be far more consistently predictable by the ADC change found at fraction number 7 and later, compared to the linear response (RECIST). The perfusion fraction and pseudo diffusion coefficient did not show sufficient prognostic value with either response assessment criteria. In conclusion this study shows that the ADC derived using high b-values may be a reliable biomarker for early assessment of radiotherapy response for brain metastases patients. The earliest response stratification can be achieved using two DW-MRI scans, one pre-treatment and one at treatment day 7–9 (equivalent to 21

  13. Effects of repeatability measures on results of fMRI sICA: a study on simulated and real resting-state effects.

    PubMed

    Remes, Jukka J; Starck, Tuomo; Nikkinen, Juha; Ollila, Esa; Beckmann, Christian F; Tervonen, Osmo; Kiviniemi, Vesa; Silven, Olli

    2011-05-15

    Spatial independent components analysis (sICA) has become a widely applied data-driven method for fMRI data, especially for resting-state studies. These sICA approaches are often based on iterative estimation algorithms and there are concerns about accuracy due to noise. Repeatability measures such as ICASSO, RAICAR and ARABICA have been introduced as remedies but information on their effects on estimates is limited. The contribution of this study was to provide more of such information and test if the repeatability analyses are necessary. We compared FastICA-based ordinary and repeatability approaches concerning mixing vector estimates. Comparisons included original FastICA, FSL4 Melodic FastICA and original and modified ICASSO. The effects of bootstrapping and convergence threshold were evaluated. The results show that there is only moderate improvement due to repeatability measures and only in the bootstrapping case. Bootstrapping attenuated power from time courses of resting-state network related ICs at frequencies higher than 0.1 Hz and made subsets of low frequency oscillations more emphasized IC-wise. The convergence threshold did not have a significant role concerning the accuracy of estimates. The performance results suggest that repeatability measures or strict converge criteria might not be needed in sICA analyses of fMRI data. Consequently, the results in existing sICA fMRI literature are probably valid in this sense. A decreased accuracy of original bootstrapping ICASSO was observed and corrected by using centrotype mixing estimates but the results warrant for thorough evaluations of data-driven methods in general. Also, given the fMRI-specific considerations, further development of sICA methods is strongly encouraged.

  14. The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

    PubMed Central

    Gnanapragasam, V. J.; Burling, K.; George, A.; Stearn, S.; Warren, A.; Barrett, T.; Koo, B.; Gallagher, F. A.; Doble, A.; Kastner, C.; Parker, R. A.

    2016-01-01

    Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5–30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI. PMID:27748407

  15. Comparison of prostate MRI-3D transrectal ultrasound fusion biopsy for first-time and repeat biopsy patients with previous atypical small acinar proliferation

    PubMed Central

    Cool, Derek W.; Romagnoli, Cesare; Izawa, Jonathan I.; Chin, Joseph; Gardi, Lori; Tessier, David; Mercado, Ashley; Mandel, Jonathan; Ward, Aaron D.; Fenster, Aaron

    2016-01-01

    Introduction: This study evaluates the clinical benefit of magnetic resonance-transrectal ultrasound (MR-TRUS) fusion biopsy over systematic biopsy between first-time and repeat prostate biopsy patients with prior atypical small acinar proliferation (ASAP). Materials: 100 patients were enrolled in a single-centre prospective cohort study: 50 for first biopsy, 50 for repeat biopsy with prior ASAP. Multiparameteric magnetic resonance imaging (MP-MRI) and standard 12-core ultrasound biopsy (Std-Bx) were performed on all patients. Targeted biopsy using MRI-TRUS fusion (Fn-Bx) was performed f suspicious lesions were identified on the pre-biopsy MP-MRI. Classification of clinically significant disease was assessed independently for the Std-Bx vs. Fn-Bx cores to compare the two approaches. Results: Adenocarcinoma was detected in 49/100 patients (26 first biopsy, 23 ASAP biopsy), with 25 having significant disease (17 first, 8 ASAP). Fn-Bx demonstrated significantly higher per-core cancer detection rates, cancer involvement, and Gleason scores for first-time and ASAP patients. However, Fn-Bx was significantly more likely to detect significant cancer missed on Std-Bx for ASAP patients than first-time biopsy patients. The addition of Fn-Bx to Std-Bx for ASAP patients had a 166.7% relative risk reduction for missing Gleason ≥ 3 + 4 disease (number needed to image with MP-MRI=10 patients) compared to 6.3% for first biopsy (number to image=50 patients). Negative predictive value of MP-MRI for negative biopsy was 79% for first-time and 100% for ASAP patients, with median followup of 32.1 ± 15.5 months. Conclusions: MR-TRUS Fn-Bx has a greater clinical impact for repeat biopsy patients with prior ASAP than biopsy-naïve patients by detecting more significant cancers that are missed on Std-Bx. PMID:27800057

  16. Modulating arithmetic fact retrieval: a single-blind, sham-controlled tDCS study with repeated fMRI measurements.

    PubMed

    Clemens, Benjamin; Jung, Stefanie; Zvyagintsev, Mikhail; Domahs, Frank; Willmes, Klaus

    2013-06-01

    Transcranial direct current stimulation (tDCS) is a non-invasive technique which has been used to modulate various cognitive functions in healthy participants as well as stroke patients. Despite the increasing number of tDCS studies, it still remains questionable whether tDCS is suitable for modulating performance in arithmetic tasks and whether a single tDCS session may cause brain activity changes that can be detected with functional magnetic resonance imaging (fMRI). We asked healthy participants to repeatedly solve simple multiplication tasks in three conditions: STIMULATION (anodal tDCS over the right angular gyrus, AG), SHAM (identical electrode set-up without stimulation), and CONTROL (no electrodes attached). Before and after tDCS, we used fMRI to examine changes in brain activity. Behavioural results indicate that a single session of tDCS did not modulate task performance significantly. However, fMRI measurements revealed that the neural correlates of multiplication were modified following a single session of anodal tDCS. In the bilateral AG, activity was significantly higher for multiplication problems rehearsed during active tDCS, as compared to multiplication problems rehearsed without tDCS or during sham tDCS. In sum, we present first neuro-functional evidence that tDCS modulates arithmetic processing. Implications of these findings for future tDCS studies and for the rehabilitation of acalculic patients with deficits in arithmetic fact retrieval are discussed.

  17. TU-C-12A-05: Repeatability Study of Reduced Field-Of-View Diffusion-Weighted MRI On Human Thyroid Gland

    SciTech Connect

    Shukla-Dave, A; Lu, Y; Hatzoglou, V; Stambuk, H; Mazaheri, Y; Banerjee, S; Shankaranarayanan, A; Deasy, J

    2014-06-15

    Purpose: To investigate the repeatability of reduced field-of-view diffusion-weighted imaging (rFOV DWI) in quantifying apparent diffusion coefficients (ADCs) for human thyroid glands in a clinical setting. Methods: Nine healthy human volunteers were enrolled and underwent 3T MRI exams. For each volunteer, 3 longitudinal exams (2 weeks apart) with 2 repetitive sessions within each exam, including rFOV and conventional full field-of-view (fFOV) DWI scans, were performed. In the acquired DWI images, a fixed-size region of interest (ROI; diameter=8mm) was placed on thyroid glands to calculate ADC. ADC was calculated using a monoexponential function with a noise correction scheme. The repeatability of ADC was assessed by using coefficient variation (CV) across sessions or exams, which was defined to be: r = 1-CV, 0 < r < 1, where CV=STD/m, STD is the standard deviation of ADC, and m is the average of ADC across sessions or exams. An experienced radiologist assessed and scored rFOV and fFOV DW images based on image characteristics (1, nondiagnostic; 2, poor; 3, satisfactory; 4, good; and 5, excellent).Analysis of variance (ANOVA) was performed to compare ADC values, CV of ADC, repeatability of ADC across sessions and exams, and radiologic scores between rFOV and fFOV DWI techniques. Results: There was no significant difference in ADC values across sessions and exams either in rFOV or fFOV DWI. The average CVs of both rFOV and fFOV DWI were less than 13%. The repeatability of ADC measurement between rFOV and fFOV DWI was not significantly different. The overall image quality was significantly higher with rFOV DWI than with fFOV DWI. Conclusion: This study suggested that ADCs from both rFOV and fFOV DWI were repeatable, but rFOV DWI had superior imaging quality for human thyroid glands in a clinical setting.

  18. Discontinuous Patterns of Brain Activation in the Psychotherapy Process of Obsessive-Compulsive Disorder: Converging Results from Repeated fMRI and Daily Self-Reports

    PubMed Central

    Schiepek, Günter; Tominschek, Igor; Heinzel, Stephan; Aigner, Martin; Dold, Markus; Unger, Annemarie; Lenz, Gerhard; Windischberger, Christian; Moser, Ewald; Plöderl, Martin; Lutz, Jürgen; Meindl, Thomas; Zaudig, Michael; Pogarell, Oliver; Karch, Susanne

    2013-01-01

    This study investigates neuronal activation patterns during the psychotherapeutic process, assuming that change dynamics undergo critical instabilities and discontinuous transitions. An internet-based system was used to collect daily self-assessments during inpatient therapies. A dynamic complexity measure was applied to the resulting time series. Critical phases of the change process were indicated by the maxima of the varying complexity. Repeated functional magnetic resonance imaging (fMRI) measurements were conducted over the course of the therapy. The study was realized with 9 patients suffering from obsessive-compulsive disorder (subtype: washing/contamination fear) and 9 matched healthy controls. For symptom-provocative stimulation individualized pictures from patients’ personal environments were used. The neuronal responses to these disease-specific pictures were compared to the responses during standardized disgust-provoking and neutral pictures. Considerably larger neuronal changes in therapy-relevant brain areas (cingulate cortex/supplementary motor cortex, bilateral dorsolateral prefrontal cortex, bilateral insula, bilateral parietal cortex, cuneus) were observed during critical phases (order transitions), as compared to non-critical phases, and also compared to healthy controls. The data indicate that non-stationary changes play a crucial role in the psychotherapeutic process supporting self-organization and complexity models of therapeutic change. PMID:23977168

  19. Social Development: 1 Year Olds

    MedlinePlus

    ... Stages Listen Español Text Size Email Print Share Social Development: 1 Year Olds Page Content Article Body During his second year, your toddler will develop a very specific image of his social world, friends, and acquaintances. He ...

  20. Repeat Targeted Prostate Biopsy under Guidance of Multiparametric MRI-Correlated Real-Time Contrast-Enhanced Ultrasound for Patients with Previous Negative Biopsy and Elevated Prostate-Specific Antigen: A Prospective Study

    PubMed Central

    Jang, Dong Ryul; Jung, Dae Chul; Oh, Young Taik; Noh, Songmi; Han, Kyunghwa; Kim, Kiwook; Rha, Koon-Ho; Choi, Young Deuk; Hong, Sung Joon

    2015-01-01

    Objectives To prospectively determine whether multi-parametric MRI (mpMRI) - contrast-enhanced ultrasound (CEUS) correlated, imaging-guided target biopsy (TB) method could improve the detection of prostate cancer in re-biopsy setting of patients with prior negative biopsy. Methods From 2012 to 2014, a total of 42 Korean men with a negative result from previous systematic biopsy (SB) and elevated prostate-specific antigen underwent 3T mpMRI and real-time CEUS guided TB. Target lesions were determined by fusion of mpMRI and CEUS. Subsequently, 12-core SB was performed by a different radiologist. We compared core-based cancer detection rates (CaDR) using the generalized linear mixed model (GLIMMIX) for each biopsy method. Results Core-based CaDR was higher in TB (17.92%, 38 of 212 cores) than in SB (6.15%, 31 of 504 cores) (p < 0.0001; GLIMMIX). In the cancer-positive TB cores, CaDR with suspicious lesions by mpMRI was higher than that by CEUS (86.8% vs. 60.5%, p= 0.02; paired t-test) and concordant rate between mpMRI and CEUS was significantly different with discordant rate (48% vs. 52%, p=0.04; McNemar’s test). Conclusion The mpMRI-CEUS correlated TB technique for the repeat prostate biopsy of patients with prior negative biopsy can improve CaDR based on the number of cores taken. PMID:26083348

  1. Language Development: 1 Year Olds

    MedlinePlus

    ... Stages Listen Español Text Size Email Print Share Language Development: 1 Year Olds Page Content Article Body ... assured, it’s not your imagination. He’s developing his language and comprehension skills right on schedule. This giant ...

  2. Heart MRI

    MedlinePlus

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  3. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  4. Your Child's Development: 1 Year (12 Months)

    MedlinePlus

    ... Year-Old Your Child’s Development: 1 Year (12 Months) KidsHealth > For Parents > Your Child’s Development: 1 Year (12 Months) A A A Your little one is now ... THIS TOPIC Your Child's Checkup: 1 Year (12 Months) Your Baby's Growth: 12 Months Your Baby's Hearing, ...

  5. MRI and low back pain

    MedlinePlus

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  6. Repeated nightmares

    MedlinePlus

    ... different from night terrors . Alternative Names Nightmares - repeated; Dream anxiety disorder References American Academy of Family Physicians. Information from your family doctor. Nightmares and night terrors in children. ...

  7. MRI-guided brachytherapy

    PubMed Central

    Tanderup, Kari; Viswanathan, Akila; Kirisits, Christian; Frank, Steven J.

    2014-01-01

    The application of MRI-guided brachytherapy has demonstrated significant growth during the last two decades. Clinical improvements in cervix cancer outcomes have been linked to the application of repeated MRI for identification of residual tumor volumes during radiotherapy. This has changed clinical practice in the direction of individualized dose administration, and mounting evidence of improved clinical outcome with regard to local control, overall survival as well as morbidity. MRI-guided prostate HDR and LDR brachytherapy has improved the accuracy of target and organs-at-risk (OAR) delineation, and the potential exists for improved dose prescription and reporting for the prostate gland and organs at risk. Furthermore, MRI-guided prostate brachytherapy has significant potential to identify prostate subvolumes and dominant lesions to allow for dose administration reflecting the differential risk of recurrence. MRI-guided brachytherapy involves advanced imaging, target concepts, and dose planning. The key issue for safe dissemination and implementation of high quality MRI-guided brachytherapy is establishment of qualified multidisciplinary teams and strategies for training and education. PMID:24931089

  8. MRI-Based Classification Models in Prediction of Mild Cognitive Impairment and Dementia in Late-Life Depression

    PubMed Central

    Lebedeva, Aleksandra K.; Westman, Eric; Borza, Tom; Beyer, Mona K.; Engedal, Knut; Aarsland, Dag; Selbaek, Geir; Haberg, Asta K.

    2017-01-01

    Objective: Late-life depression (LLD) is associated with development of different types of dementia. Identification of LLD patients, who will develop cognitive decline, i.e., the early stage of dementia would help to implement interventions earlier. The purpose of this study was to assess whether structural brain magnetic resonance imaging (MRI) in LLD patients can predict mild cognitive impairment (MCI) or dementia 1 year prior to the diagnosis. Methods: LLD patients underwent brain MRI at baseline and repeated clinical assessment after 1-year. Structural brain measurements were obtained using Freesurfer software (v. 5.1) from the T1W brain MRI images. MRI-based Random Forest classifier was used to discriminate between LLD who developed MCI or dementia after 1-year follow-up and cognitively stable LLD. Additionally, a previously established Random Forest model trained on 185 patients with Alzheimer’s disease (AD) vs. 225 cognitively normal elderly from the Alzheimer’s disease Neuroimaging Initiative was tested on the LLD data set (ADNI model). Results: MCI and dementia diagnoses were predicted in LLD patients with 76%/68%/84% accuracy/sensitivity/specificity. Adding the baseline Mini-Mental State Examination (MMSE) scores to the models improved accuracy/sensitivity/specificity to 81%/75%/86%. The best model predicted MCI status alone using MRI and baseline MMSE scores with accuracy/sensitivity/specificity of 89%/85%/90%. The most important region for all the models was right ventral diencephalon, including hypothalamus. Its volume correlated negatively with the number of depressive episodes. ADNI model trained on AD vs. Controls using SV could predict MCI-DEM patients with 67% accuracy. Conclusion: LDD patients developing MCI and dementia can be discriminated from LLD patients remaining cognitively stable with good accuracy based on baseline structural MRI alone. Baseline MMSE score improves prediction accuracy. Ventral diencephalon, including the hypothalamus

  9. MRI-Based Classification Models in Prediction of Mild Cognitive Impairment and Dementia in Late-Life Depression.

    PubMed

    Lebedeva, Aleksandra K; Westman, Eric; Borza, Tom; Beyer, Mona K; Engedal, Knut; Aarsland, Dag; Selbaek, Geir; Haberg, Asta K

    2017-01-01

    Objective: Late-life depression (LLD) is associated with development of different types of dementia. Identification of LLD patients, who will develop cognitive decline, i.e., the early stage of dementia would help to implement interventions earlier. The purpose of this study was to assess whether structural brain magnetic resonance imaging (MRI) in LLD patients can predict mild cognitive impairment (MCI) or dementia 1 year prior to the diagnosis. Methods: LLD patients underwent brain MRI at baseline and repeated clinical assessment after 1-year. Structural brain measurements were obtained using Freesurfer software (v. 5.1) from the T1W brain MRI images. MRI-based Random Forest classifier was used to discriminate between LLD who developed MCI or dementia after 1-year follow-up and cognitively stable LLD. Additionally, a previously established Random Forest model trained on 185 patients with Alzheimer's disease (AD) vs. 225 cognitively normal elderly from the Alzheimer's disease Neuroimaging Initiative was tested on the LLD data set (ADNI model). Results: MCI and dementia diagnoses were predicted in LLD patients with 76%/68%/84% accuracy/sensitivity/specificity. Adding the baseline Mini-Mental State Examination (MMSE) scores to the models improved accuracy/sensitivity/specificity to 81%/75%/86%. The best model predicted MCI status alone using MRI and baseline MMSE scores with accuracy/sensitivity/specificity of 89%/85%/90%. The most important region for all the models was right ventral diencephalon, including hypothalamus. Its volume correlated negatively with the number of depressive episodes. ADNI model trained on AD vs. Controls using SV could predict MCI-DEM patients with 67% accuracy. Conclusion: LDD patients developing MCI and dementia can be discriminated from LLD patients remaining cognitively stable with good accuracy based on baseline structural MRI alone. Baseline MMSE score improves prediction accuracy. Ventral diencephalon, including the hypothalamus

  10. Shoulder MRI

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  11. Knee MRI

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  12. Shoulder MRI

    MedlinePlus

    ... of the shoulder uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  13. Knee MRI

    MedlinePlus

    ... of the knee uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  14. MRI renaissance.

    PubMed

    Hensley, S

    1997-12-01

    A few years ago, magnetic resonance imaging was healthcare's version of a foreign sports car-flashy, expensive and impractical. Now, after years in the doldrums, sales of MRI systems are roaring back. An aging fleet of MRI scanners due for replacement and a hearty increase in doctors' use of the versatile imaging tools are combining to fuel the surge in demand, vendors and customers say.

  15. Portable MRI

    SciTech Connect

    Espy, Michelle A.

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  16. MRI (Magnetic Resonance Imaging)

    MedlinePlus

    ... and Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... usually given through an IV in the arm. MRI Research Programs at FDA Magnetic Resonance Imaging (MRI) ...

  17. MRI Safety during Pregnancy

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z MRI Safety During Pregnancy Magnetic resonance imaging (MRI) Illness ... during the exam? Contrast material MRI during pregnancy Magnetic resonance imaging (MRI) If you are pregnant and your doctor ...

  18. Battlefield MRI

    DOE PAGES

    Espy, Michelle

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  19. Sodium MRI.

    PubMed

    Ouwerkerk, Ronald

    2011-01-01

    Sodium ((23)Na) imaging has a place somewhere between (1)H-MRI and MR spectroscopy (MRS). Like MRS it potentially provides information on metabolic processes, but only one single resonance of ionic (23)Na is observed. Therefore pulse sequences do not need to code for a chemical shift dimension, allowing (23)Na images to be obtained at high resolutions as compared to MRS. In this chapter the biological significance of sodium in the brain will be discussed, as well as methods for observing it with (23)Na-MRI. Many vital cellular processes and interactions in excitable tissues depend on the maintenance of a low intracellular and high extracellular sodium concentration. Healthy cells maintain this concentration gradient at the cost of energy. Leaky cell membranes or an impaired energy metabolism immediately leads to an increase in cytosolic total tissue sodium. This makes sodium a biomarker for ischemia, cancer, excessive tissue activation, or tissue damage as might be caused by ablation therapy. Special techniques allow quantification of tissue sodium for the monitoring of disease or therapy in longitudinal studies or preferential observation of the intracellular component of the tissue sodium. New methods and high-field magnet technology provide new opportunities for (23)Na-MRI in clinical and biomedical research.

  20. Competitive advantage of PET/MRI.

    PubMed

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.

  1. Choking first aid - infant under 1 year - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100221.htm Choking first aid - infant under 1 year - series—Part 1 To ... Loss of consciousness if blockage is not cleared FIRST AID 1. DO NOT perform these steps if the ...

  2. Choking first aid - adult or child over 1 year - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100222.htm Choking first aid - adult or child over 1 year - series—Part ... occur in as little as 4 minutes. Rapid first aid for choking can save a life. The universal ...

  3. The Safe Dates program: 1-year follow-up results.

    PubMed Central

    Foshee, V A; Bauman, K E; Greene, W F; Koch, G G; Linder, G F; MacDougall, J E

    2000-01-01

    OBJECTIVES: An earlier report described desirable 1-month follow-up effects of the Safe Dates program on psychological, physical, and sexual dating violence. Mediators of the program-behavior relationship also were identified. The present report describes the 1-year follow-up effects of the Safe Dates program. METHODS: Fourteen schools were in the randomized experiment. Data were gathered by questionnaires in schools before program activities and 1 year after the program ended. RESULTS: The short-term behavioral effects had disappeared at 1 year, but effects on mediating variables such as dating violence norms, conflict management skills, and awareness of community services for dating violence were maintained. CONCLUSIONS: The findings are considered in the context of why program effects might have decayed and the possible role of boosters for effect maintenance. PMID:11029999

  4. Otitis Media and Language Development at 1 Year of Age.

    ERIC Educational Resources Information Center

    Wallace, Ina F.; And Others

    1988-01-01

    Fifteen 1-year-olds without otitis media were compared to 12 babies who were otitis positive. No significant differences were detected on the Bayley Scales of Infant Development or the Sequenced Inventory of Communication Development (SICD) Receptive scale. However, the otitis-positive group exhibited lower SICD Expressive scores than the…

  5. Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Li, Wen; Zinbarg, Richard E.

    2007-01-01

    The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

  6. Gait Asymmetries Persist 1 Year After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    White, Kathleen; Logerstedt, David; Snyder-Mackler, Lynn

    2013-01-01

    Background: After anterior cruciate ligament reconstruction (ACLR), motivation to return to previous levels of activity is high. Very few studies have used return-to-activity criteria to determine when to permit athletic play. Return-to-activity measures objectively evaluate functional limb symmetry; however, previous biomechanical studies have found gait deviations in these individuals that persist up to 2 years after surgery. Purpose: To evaluate gait biomechanics in a specific cohort of ACL patients 1 year after surgery and retrospectively compare individuals who pass return-to-activity criteria 6 months after surgery with those who fail. Study Design: Prospective analysis. Methods: A total of 40 athletes who participated regularly (>50 h/y) in cutting, jumping, and pivoting activities and who sustained an isolated, unilateral ACL rupture were included in this study. All participants underwent reconstruction by the same surgeon and received individualized postoperative rehabilitation. Performance-based and self-report data were measured 6 months after surgery to assess readiness to return to activity (90% outcome required to pass); 20 subjects passed return-to-activity criteria and 20 subjects did not. Motion analysis was performed 1 year after surgery, and knee flexion angles, moments, and excursions were measured during gait and evaluated for all subjects. Results: There was no limb × group interaction or effect of group for all measures. Decreased knee measures were seen on the involved limb compared with the uninvolved limb for all subjects, and failed subjects demonstrated larger differences between limbs. Conclusion: Patients continued to demonstrate biomechanical limb asymmetries 1 year after ACLR, regardless of performance-based measures at 6 months. Early return to activity did not ensure limb symmetry at 1 year. Clinical Relevance: Gait asymmetries were seen in all subjects 1 year after surgery regardless of status at 6 months. Potentially prolonging

  7. Pulmonary toxicity of cyclophosphamide: a 1-year study

    SciTech Connect

    Morse, C.C.; Sigler, C.; Lock, S.; Hakkinen, P.J.; Haschek, W.M.; Witschi, H.P.

    1985-01-01

    The development of cyclophosphamide-induced pulmonary lesions over a 1-year period was studied in mice. Male BALB/c mice received a single intraperitoneal injection of 100 mg/kg of cyclophosphamide. Within 3 weeks there were scattered foci of intraalveolar foamy macrophages. With time, these foci increased in size and, 1 year later, occupied large areas in all lung lobes. There was also diffuse interstitial fibrosis. Chemical determination done 3, 12, 24, and 52 weeks after cyclophosphamide showed that lungs of animals treated with cyclophosphamide had significantly more hydroxyproline per lung than controls. One year after cyclophosphamide pressure - volume curves measured in vivo were shifted down and to the right and total lung volumes were decreased. A single injection of cyclophosphamide produced an irreversible and progressive pulmonary lesion. 16 references, 5 figures, 3 tables.

  8. Secondary preventive medication persistence and adherence 1 year after stroke

    PubMed Central

    Olson, D.M.; Zhao, X.; Pan, W.; Zimmer, L.O.; Goldstein, L.B.; Alberts, M.J.; Fagan, S.C.; Fonarow, G.C.; Johnston, S.C.; Kidwell, C.; LaBresh, K.A.; Ovbiagele, B.; Schwamm, L.; Peterson, E.D.

    2011-01-01

    Objective: Data on long-term use of secondary prevention medications following stroke are limited. The Adherence eValuation After Ischemic stroke–Longitudinal (AVAIL) Registry assessed patient, provider, and system-level factors influencing continuation of prevention medications for 1 year following stroke hospitalization discharge. Methods: Patients with ischemic stroke or TIA discharged from 106 hospitals participating in the American Heart Association Get With The Guidelines–Stroke program were surveyed to determine their use of warfarin, antiplatelet, antihypertensive, lipid-lowering, and diabetes medications from discharge to 12 months. Reasons for stopping medications were ascertained. Persistence was defined as continuation of all secondary preventive medications prescribed at hospital discharge, and adherence as continuation of prescribed medications except those stopped according to health care provider instructions. Results: Of the 2,880 patients enrolled in AVAIL, 88.4% (2,457 patients) completed 1-year interviews. Of these, 65.9% were regimen persistent and 86.6% were regimen adherent. Independent predictors of 1-year medication persistence included fewer medications prescribed at discharge, having an adequate income, having an appointment with a primary care provider, and greater understanding of why medications were prescribed and their side effects. Independent predictors of adherence were similar to those for persistence. Conclusions: Although up to one-third of stroke patients discontinued one or more secondary prevention medications within 1 year of hospital discharge, self-discontinuation of these medications is uncommon. Several potentially modifiable patient, provider, and system-level factors associated with persistence and adherence may be targets for future interventions. PMID:21900638

  9. Stability of physical assessment of older drivers over 1 year.

    PubMed

    Smith, Andrew; Marshall, Shawn; Porter, Michelle; Ha, Linda; Bédard, Michel; Gélinas, Isabelle; Man-Son-Hing, Malcolm; Mazer, Barbara; Rapoport, Mark; Tuokko, Holly; Vrkljan, Brenda

    2013-12-01

    Older adults represent the fastest-growing population of drivers with a valid driver's licence. Also common in this age group are multiple chronic medical conditions that may have an effect on physical function and driving ability. Determining the reliability of physical measures used to assess older drivers' functional ability is important to identifying those who are safe to continue driving. Most previous reliability studies of clinical physical measures of health used test-retest intervals shorter than those between patient visits with a clinician. In the present study we examined a more clinically representative interval of 1 year to determine the stability of commonly used physical measures collected during the Candrive II prospective cohort study of older drivers. Reliability statistics indicate that the sequential finger-thumb opposition, rapid pace walk and the Pelli-Robson contrast sensitivity tests have adequate stability over 1 year. Poor stability was observed for the one-legged stance and Snellen visual acuity test. Several assessments with nominal data (Marottoli method [functional neck range of motion], whispered voice test, range of motion and strength testing) lacked sufficient variability to conduct reliability analyses; however, a lack of variability between test days suggests consistency over a 1-year time frame. Our results provide evidence that specific physical measures are stable in monitoring functional ability over the course of a year.

  10. Sinus MRI scan

    MedlinePlus

    ... sinuses. The test is noninvasive. MRI uses powerful magnets and radio waves instead of radiation. Signals from ... in the eyes. Because the MRI contains a magnet, metal-containing objects such as pens, pocketknives, and ...

  11. Arm MRI scan

    MedlinePlus

    ... arm MRI (magnetic resonance imaging) scan uses strong magnets to create pictures of the upper and lower ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  12. MRI Safety during Pregnancy

    MedlinePlus

    ... 20 to 40 minutes. top of page Contrast material For some MRI exams, a contrast material called gadolinium will need to be injected into a vein in the arm. While contrast material sometimes improves the MRI images, during pregnancy the ...

  13. Acquired childhood aphasia. Outcome 1 year after onset.

    PubMed

    Loonen, M C; van Dongen, H R

    1990-12-01

    The effects of the variables age at onset, cause, severity and bilaterality of lesion, and type of aphasia on course and outcome were investigated in a group of 28 aphasic children. Analysis of spontaneous speech and tests of auditory verbal comprehension were used to determine the presence of aphasia. The severity of the cerebral lesion was assessed using a rating scale for computed tomographic scans. Most of the children had not recovered completely 1 year after onset. Recovery was significantly different according to etiological categories. Complete recovery was seen in the majority of traumatic cases.

  14. Uterine cirsoid aneurysm: MRI and MRA

    SciTech Connect

    Joja, Ikuo; Asakawa, Mari; Motoyama, Kazumi

    1996-03-01

    Uterine cirsoid aneurysm is uncommon. It is important to make a diagnosis of this disease preoperatively, because repeated curettages may induce life-threatening massive genital bleeding. We present a case of a 51-year-old woman with uterine cirsoid aneurysm in whom MRI and MRA were very useful for the preoperative diagnosis. The radiologic appearances on ultrasonography, CT, conventional SE MRI, MRA, dynamic MRI, and pelvic angiography are presented. Conventional SE T1-weighted and T2-weighted images demonstrated multiple flow voids in the uterus and bilateral adnexal regions. MRA demonstrated a cluster of distinct, tortuous, and coiled vascular channels in the pelvis. MRA could obtain images almost equal to angiography and was considered to be an excellent noninvasive imaging technique for the diagnosis of uterine cirsoid aneurysm. 28 refs., 7 figs

  15. Tractography of the optic radiation: a repeatability and reproducibility study.

    PubMed

    Dayan, Michael; Kreutzer, Sylvia; Clark, Chris A

    2015-04-01

    Our main objective was to evaluate the repeatability and reproducibility of optic radiation (OR) reconstruction from diffusion MRI (dMRI) data. 14 adults were scanned twice with the same 60-direction dMRI sequence. Peaks in the diffusion profile were estimated with the single tensor (ST), Q-ball (QSH) and persistent angular structure (PAS) methods. Segmentation of the OR was performed by two experimenters with probabilistic tractography based on a manually drawn region-of-interest (ROI) protocol typically employed for OR segmentation, with both standard and extended sets of ROIs. The repeatability and reproducibility were assessed by calculating the intra-class correlation coefficient (ICC) of intra- and inter-rater experiments, respectively. ICCs were calculated for commonly used dMRI metrics (FA, MD, AD, RD) and anatomical dimensions of the optic radiation (distance from Meyer's loop to the temporal pole, ML-TP), as well as the Dice similarity coefficient (DSC) between the raters' OR segmentation. Bland-Altman plots were also calculated to investigate bias and variability in the reproducibility measurements. The OR was successfully reconstructed in all subjects by both raters. The ICC was found to be in the good to excellent range for both repeatability and reproducibility of the dMRI metrics, DSC and ML-TP distance. The Bland-Altman plots did not show any apparent systematic bias for any quantities. Overall, higher ICC values were found for the multi-fiber methods, QSH and PAS, and for the standard set of ROIs. Considering the good to excellent repeatability and reproducibility of all the quantities investigated, these findings support the use of multi-fiber OR reconstruction with a limited number of manually drawn ROIs in clinical applications utilizing either OR microstructure characterization or OR dimensions, as is the case in neurosurgical planning for temporal lobectomy.

  16. Serial magnetic resonance imaging of global and regional left ventricular remodeling during 1 year after acute myocardial infarction.

    PubMed

    Schroeder, A P; Houlind, K; Pedersen, E M; Nielsen, T T; Egeblad, H

    2001-01-01

    Biplane long-axis cine MRI was performed in 51 patients 1, 13, 26, and 52 weeks after their first AMI. LV mass index (LVMI) was significantly increased 1 week after AMI (84.3 +/- 16.9 vs. 68.1 +/- 11.4 g/m(2) controls, n = 48, p < 0.001), presumably owing to edema of the infarcted myocardium. Six months after AMI, LVMI decreased to 76.5 +/- 16.4 g/m(2), but had again augmented after 1 year (81.8 +/- 17.3 g/m(2), p < 0.05), suggesting late, compensatory left ventricular hypertrophy. In patients treated with primary percutaneous transluminal coronary angioplasty, LVMI decreased 5% over 1 year, while LVMI increased 10% in patients receiving thrombolysis (p < 0.05). In the entire population, the global increase in LVMI 1 year after AMI seemed to reflect global cavity dilatation with unchanged thickness of the vital myocardium. In conclusion, in patients receiving contemporary treatment, LV remodeling only partially complied with the classical patho-anatomical concept.

  17. Varicella paediatric hospitalisations in Belgium: a 1-year national survey

    PubMed Central

    Blumental, Sophie; Sabbe, Martine; Lepage, Philippe

    2016-01-01

    Background Varicella universal vaccination (UV) has been implemented in many countries for several years. Nevertheless, varicella UV remains debated in Europe and few data are available on the real burden of infection. We assessed the burden of varicella in Belgium through analysis of hospitalised cases during a 1-year period. Methods Data on children admitted to hospital with varicella were collected through a national network from November 2011 to October 2012. Inclusion criteria were either acute varicella or related complications up to 3 weeks after the rash. Results Participation of 101 hospitals was obtained, covering 97.7% of the total paediatric beds in Belgium. 552 children were included with a median age of 2.1 years. Incidence of paediatric varicella hospitalisations reached 29.5/105 person-years, with the highest impact among those 0–4 years old (global incidence and odds of hospitalisation: 79/105 person-years and 1.6/100 varicella cases, respectively). Only 14% (79/552) of the cohort had an underlying chronic condition. 65% (357/552) of children had ≥1 complication justifying their admission, 49% were bacterial superinfections and 10% neurological disorders. Only a quarter of children (141/552) received acyclovir. Incidence of complicated hospitalised cases was 19/105 person-years. Paediatric intensive care unit admission and surgery were required in 4% and 3% of hospitalised cases, respectively. Mortality among Belgian paediatric population was 0.5/106 and fatality ratio 0.2% among our cohort. Conclusions Varicella demonstrated a substantial burden of disease in Belgian children, especially among the youngest. Our thorough nationwide study, run in a country without varicella UV, offers data to support varicella UV in Belgium. PMID:26130380

  18. Association between Age and Striatal Volume Stratified by CAG Repeat Length in Prodromal Huntington Disease

    PubMed Central

    Aylward, Elizabeth; Mills, James; Liu, Dawei; Nopoulos, Peggy; Ross, Christopher A.; Pierson, Ronald; Paulsen, Jane S.

    2011-01-01

    Background: Longer CAG repeat length is associated with faster clinical progression in Huntington disease, although the effect of higher repeat length on brain atrophy is not well documented. Method: Striatal volumes were obtained from MRI scans of 720 individuals with prodromal Huntington disease. Striatal volume was plotted against age separately for groups with CAG repeat lengths of 38–39, 40, 41, 42, 43, 44, 45, 46, and 47–54. Results: Slopes representing the association between age and striatal volume were significantly steeper as CAG repeat length increased. Discussion: Although cross-sectional, these data suggest that striatal atrophy, like clinical progression, may occur faster with higher CAG repeat lengths. PMID:21593963

  19. Repeating the Past

    NASA Astrophysics Data System (ADS)

    Moore, John W.

    1998-05-01

    As part of the celebration of the Journal 's 75th year, we are scanning each Journal issue from 25, 50, and 74 years ago. Many of the ideas and practices described are so similar to present-day "innovations" that George Santayana's adage (1) "Those who cannot remember the past are condemned to repeat it" comes to mind. But perhaps "condemned" is too strong - sometimes it may be valuable to repeat something that was done long ago. One example comes from the earliest days of the Division of Chemical Education and of the Journal.

  20. Increased BOLD activation in the left parahippocampal cortex after 1 year of medical school: an association with cumulative verbal memory learning.

    PubMed

    Bernier, Michaël; Gauvreau, Claudie; Theriault, Denis; Madrolle, Stéphanie; Lepage, Jean-François; Whittingstall, Kevin

    2016-01-06

    Although several studies have shown left-right hippocampus asymmetry during learning, it is unclear whether such asymmetry also exists for the parahippocampal cortex, a structure within the limbic system that is also involved in memory and learning. Using a common mental navigation task known to activate the bilateral parahippocampal cortex, this study aimed at determining how BOLD activation in these two areas changes after 1 year of medical school, a program characterized by intensive verbal learning. Fifteen first-year medical students participated in this study and underwent two sessions of functional MRI, at a 1-year interval. In the first session, we observed marginal differences between left and right parahippocampal cortex activity. However, 1 year later, left parahippocampal activation significantly increased (+4.7%), whereas the right remained stable. These results bring new information as to how intensive learning can modify regional metabolism in the human brain and how the left parahippocampal region is particularly important for cumulative verbal memory.

  1. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    SciTech Connect

    Paulson, Eric S.; Erickson, Beth; Schultz, Chris; Allen Li, X.

    2015-01-15

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  2. The Effect of fMRI (Noise) on Cognitive Control

    ERIC Educational Resources Information Center

    Hommel, Bernhard; Fischer, Rico; Colzato, Lorenza S.; van den Wildenberg, Wery P. M.; Cellini, Cristiano

    2012-01-01

    Stressful situations, the aversiveness of events, or increases in task difficulty (e.g., conflict) have repeatedly been shown to be capable of triggering attentional control adjustments. In the present study we tested whether the particularity of an fMRI testing environment (i.e., EPI noise) might result in such increases of the cognitive control…

  3. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  4. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  5. Lumbar MRI scan

    MedlinePlus

    ... may need a lumbar MRI if you have: Low back pain that does not get better after treatment Leg ... spine Injury or trauma to the lower spine Low back pain and a history or signs of cancer Multiple ...

  6. MRI of the Breast

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  7. MRI of the Prostate

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  8. MRI of the Chest

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  9. Magnetic Resonance Imaging (MRI)

    MedlinePlus

    ... problems (in men)Path to improved healthIf your primary care doctor determines that you should have an MRI, ... may not apply to everyone. Talk to your family doctor to find out if this information applies to ...

  10. MRI of the Breast

    MedlinePlus

    ... of the breast uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  11. Cervical MRI scan

    MedlinePlus

    ... magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the part of the ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  12. Leg MRI scan

    MedlinePlus

    ... resonance imaging) scan of the leg uses strong magnets to create pictures of the leg. This may ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  13. Shoulder MRI scan

    MedlinePlus

    ... an imaging test that uses energy from powerful magnets and to create pictures of the shoulder area. ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed in the room ...

  14. Molecular fMRI

    PubMed Central

    Bartelle, Benjamin B.; Barandov, Ali

    2016-01-01

    Comprehensive analysis of brain function depends on understanding the dynamics of diverse neural signaling processes over large tissue volumes in intact animals and humans. Most existing approaches to measuring brain signaling suffer from limited tissue penetration, poor resolution, or lack of specificity for well-defined neural events. Here we discuss a new brain activity mapping method that overcomes some of these problems by combining MRI with contrast agents sensitive to neural signaling. The goal of this “molecular fMRI” approach is to permit noninvasive whole-brain neuroimaging with specificity and resolution approaching current optical neuroimaging methods. In this article, we describe the context and need for molecular fMRI as well as the state of the technology today. We explain how major types of MRI probes work and how they can be sensitized to neurobiological processes, such as neurotransmitter release, calcium signaling, and gene expression changes. We comment both on past work in the field and on challenges and promising avenues for future development. SIGNIFICANCE STATEMENT Brain researchers currently have a choice between measuring neural activity using cellular-level recording techniques, such as electrophysiology and optical imaging, or whole-brain imaging methods, such as fMRI. Cellular level methods are precise but only address a small portion of mammalian brains; on the other hand, whole-brain neuroimaging techniques provide very little specificity for neural pathways or signaling components of interest. The molecular fMRI techniques we discuss have particular potential to combine the specificity of cellular-level measurements with the noninvasive whole-brain coverage of fMRI. On the other hand, molecular fMRI is only just getting off the ground. This article aims to offer a snapshot of the status and future prospects for development of molecular fMRI techniques. PMID:27076413

  15. Optogenetic Functional MRI

    PubMed Central

    Lin, Peter; Fang, Zhongnan; Liu, Jia; Lee, Jin Hyung

    2016-01-01

    The investigation of the functional connectivity of precise neural circuits across the entire intact brain can be achieved through optogenetic functional magnetic resonance imaging (ofMRI), which is a novel technique that combines the relatively high spatial resolution of high-field fMRI with the precision of optogenetic stimulation. Fiber optics that enable delivery of specific wavelengths of light deep into the brain in vivo are implanted into regions of interest in order to specifically stimulate targeted cell types that have been genetically induced to express light-sensitive trans-membrane conductance channels, called opsins. fMRI is used to provide a non-invasive method of determining the brain's global dynamic response to optogenetic stimulation of specific neural circuits through measurement of the blood-oxygen-level-dependent (BOLD) signal, which provides an indirect measurement of neuronal activity. This protocol describes the construction of fiber optic implants, the implantation surgeries, the imaging with photostimulation and the data analysis required to successfully perform ofMRI. In summary, the precise stimulation and whole-brain monitoring ability of ofMRI are crucial factors in making ofMRI a powerful tool for the study of the connectomics of the brain in both healthy and diseased states. PMID:27167840

  16. Variability in Muscle Damage after Eccentric Exercise and the Repeated Bout Effect

    ERIC Educational Resources Information Center

    Chen, Trevor C.

    2006-01-01

    The first purpose of this study was to determine a possible explanation for the variability in the response to eccentric exercise by having participants repeat the same exercise 1 year apart. The second purpose was to examine whether initial injury in response to eccentric exercise was associated with the extent of the repeated bout effect (RBE).…

  17. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  18. Multidimensional diffusion MRI

    NASA Astrophysics Data System (ADS)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  19. Repeat Customer Success in Extension

    ERIC Educational Resources Information Center

    Bess, Melissa M.; Traub, Sarah M.

    2013-01-01

    Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

  20. 78 FR 65594 - Vehicular Repeaters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ... changes, and on whether current mobile repeater filter technologies can support reduced frequency... feasibility of adapting SAW filters, or other filter technology, for mobile repeater use. We particularly... mobile repeaters by public safety licensees on certain frequencies in the VHF band. DATES:...

  1. Radiotherapy Planning using MRI

    PubMed Central

    Schmidt, Maria A; Payne, Geoffrey S

    2016-01-01

    The use of Magnetic Resonance Imaging (MRI) in Radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimised, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT. PMID:26509844

  2. Magnetic Resonance Imaging (MRI) (For Teens)

    MedlinePlus

    ... the MRI table. A specially trained technician (or "tech") operates the MRI machine. He or she may ... can't stay still during MRI. Sometimes MRI techs sedate teens who have trouble relaxing inside the ...

  3. RepeatsDB: a database of tandem repeat protein structures

    PubMed Central

    Di Domenico, Tomás; Potenza, Emilio; Walsh, Ian; Gonzalo Parra, R.; Giollo, Manuel; Minervini, Giovanni; Piovesan, Damiano; Ihsan, Awais; Ferrari, Carlo; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2014-01-01

    RepeatsDB (http://repeatsdb.bio.unipd.it/) is a database of annotated tandem repeat protein structures. Tandem repeats pose a difficult problem for the analysis of protein structures, as the underlying sequence can be highly degenerate. Several repeat types haven been studied over the years, but their annotation was done in a case-by-case basis, thus making large-scale analysis difficult. We developed RepeatsDB to fill this gap. Using state-of-the-art repeat detection methods and manual curation, we systematically annotated the Protein Data Bank, predicting 10 745 repeat structures. In all, 2797 structures were classified according to a recently proposed classification schema, which was expanded to accommodate new findings. In addition, detailed annotations were performed in a subset of 321 proteins. These annotations feature information on start and end positions for the repeat regions and units. RepeatsDB is an ongoing effort to systematically classify and annotate structural protein repeats in a consistent way. It provides users with the possibility to access and download high-quality datasets either interactively or programmatically through web services. PMID:24311564

  4. MRI of the lung: state of the art.

    PubMed

    Wielpütz, Mark; Kauczor, Hans-Ulrich

    2012-01-01

    Magnetic resonance imaging (MRI) of the lung is technically challenging due to the low proton density and fast signal decay of the lung parenchyma itself. Additional challenges consist of tissue loss, hyperinflation, and hypoxic hypoperfusion, e.g., in emphysema, a so-called "minus-pathology". However, pathological changes resulting in an increase of tissue ("plus-pathology"), such as atelectases, nodules, infiltrates, mucus, or pleural effusion, are easily depicted with high diagnostic accuracy. Although MRI is inferior or at best equal to multi-detector computed tomography (MDCT) for the detection of subtle morphological features, MRI now offers an increasing spectrum of functional imaging techniques such as perfusion assessment and measurement of ventilation and respiratory mechanics that are superior to what is possible with MDCT. Without putting patients at risk with ionizing radiation, repeated examinations allow for the evaluation of the course of lung disease and monitoring of the therapeutic response through quantitative imaging, providing a level of functional detail that cannot be obtained by any other single imaging modality. As such, MRI will likely be used for clinical applications beyond morphological imaging for many lung diseases. In this article, we review the technical aspects and protocol suggestions for chest MRI and discuss the role of MRI in the evaluation of nodules and masses, airway disease, respiratory mechanics, ventilation, perfusion and hemodynamics, and pulmonary vasculature.

  5. Getting an MRI (For Kids)

    MedlinePlus

    ... Happens in the Operating Room? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) A A A en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed ...

  6. Contrast agents for MRI.

    PubMed

    Shokrollahi, H

    2013-12-01

    Contrast agents are divided into two categories. The first one is paramagnetic compounds, including lanthanides like gadolinium, which mainly reduce the longitudinal (T1) relaxation property and result in a brighter signal. The second class consists of super-paramagnetic magnetic nanoparticles (SPMNPs) such as iron oxides, which have a strong effect on the transversal (T2) relaxation properties. SPMNPs have the potential to be utilized as excellent probes for magnetic resonance imaging (MRI). For instance, clinically benign iron oxide and engineered ferrite nanoparticles provide a good MRI probing capability for clinical applications. Furthermore, the limited magnetic property and inability to escape from the reticuloendothelial system (RES) of the used nanoparticles impede their further advancement. Therefore, it is necessary to develop the engineered magnetic nanoparticle probes for the next-generation molecular MRI. Considering the importance of MRI in diagnosing diseases, this paper presents an overview of recent scientific achievements in the development of new synthetic SPMNP probes whereby the sensitive and target-specific observation of biological events at the molecular and cellular levels is feasible.

  7. Repeated exposure of the developing rat brain to magnetic resonance imaging did not affect neurogenesis, cell death or memory function

    SciTech Connect

    Zhu, Changlian; Gao, Jianfeng; Li, Qian; Huang, Zhiheng; Zhang, Yu; Li, Hongfu; Kuhn, Hans-Georg; Blomgren, Klas

    2011-01-07

    Research highlights: {yields} The effect of MRI on the developing brain is a matter of debate. {yields} Repeated exposure to MRI did not affect neurogenesis. {yields} Memory function was not affected by repeated MRI during development. {yields} Neither late gestation nor young postnatal brains were affected by MRI. {yields} Repeated MRI did not cause cell death in the neurogenic region of the hippocampus. -- Abstract: The effect of magnetic fields on the brain is a matter of debate. The objective of this study was to investigate whether repeated exposure to strong magnetic fields, such as during magnetic resonance imaging (MRI), could elicit changes in the developing rat brain. Embryonic day 15 (E15) and postnatal day 14 (P14) rats were exposed to MRI using a 7.05 T MR system. The animals were anesthetized and exposed for 35 min per day for 4 successive days. Control animals were anesthetized but no MRI was performed. Body temperature was maintained at 37 {sup o}C. BrdU was injected after each session (50 mg/kg). One month later, cell proliferation, neurogenesis and astrogenesis in the dentate gyrus were evaluated, revealing no effects of MRI, neither in the E15, nor in the P14 group. DNA damage in the dentate gyrus in the P14 group was evaluated on P18, 1 day after the last session, using TUNEL staining. There was no difference in the number of TUNEL-positive cells after MRI compared with controls, neither in mature neurons, nor in newborn progenitors (BrdU/TUNEL double-labeled cells). Novel object recognition was performed to assess memory function 1 month after MRI. There was no difference in the recognition index observed after MRI compared with the control rats, neither for the E15, nor for the P14 group. In conclusion, repeated exposure to MRI did not appear to affect neurogenesis, cell death or memory function in rats, neither in late gestation (E15-E18) nor in young postnatal (P14-P17) rats.

  8. Bone mineral density at diagnosis of celiac disease and after 1 year of gluten-free diet.

    PubMed

    Pantaleoni, Stefano; Luchino, Massimo; Adriani, Alessandro; Pellicano, Rinaldo; Stradella, Davide; Ribaldone, Davide Giuseppe; Sapone, Nicoletta; Isaia, Gian Carlo; Di Stefano, Marco; Astegiano, Marco

    2014-01-01

    Atypical or silent celiac disease may go undiagnosed for many years and can frequently lead to loss of bone mineral density, with evolution to osteopenia or osteoporosis. The prevalence of the latter conditions, in case of new diagnosis of celiac disease, has been evaluated in many studies but, due to the variability of epidemiologic data and patient features, the results are contradictory. The aim of this study was to evaluate bone mineral density by dual-energy X-ray absorptiometry in 175 consecutive celiac patients at time of diagnosis (169 per-protocol, 23 males, 146 females; average age 38.9 years). Dual-energy X-ray absorptiometry was repeated after 1 year of gluten-free diet in those with T-score value <-1 at diagnosis. Stratification of patients according to sex and age showed a higher prevalence of low bone mineral density in men older than 30 years and in women of all ages. A 1-year gluten-free diet led to a significant improvement in lumbar spine and femoral neck mean T-score value. We propose that dual-energy X-ray absorptiometry should be performed at diagnosis of celiac disease in all women and in male aged >30 years, taking into account each risk factor in single patients.

  9. Resolution of NASH with weight loss documented by hepatic MRI.

    PubMed

    Singh, Vasvi; Luthra, Saurav; Elajami, Tarec K; Welty, Francine K

    2015-01-06

    A 57-year-old Asian woman with type 2 diabetes mellitus, hypertension, obesity, dyslipidaemia and history of breast cancer, was referred to the cardiovascular health and lipid centre for evaluation and management of dyslipidaemia and NASH (Non-alcoholic steatohepatitis) in 2010. She originally had a detailed work up at the liver clinic for elevated liver enzymes, with no associated symptoms. Initial hepatic MRI on 22 January 2007 showed diffuse fatty infiltration quantitated at 15%. We counselled her on lifestyle modifications, including dietary measures and exercise, geared toward weight loss. Over the next 2 years, she lost 24.5 lbs; repeat hepatic MRI on 22 December 2011 showed 6% hepatic fat, which is within the normal range. This case demonstrates the efficacy of significant weight loss in the improvement and resolution of NASH. We believe that this is the first case report documenting this through liver MRI.

  10. Resolution of NASH with weight loss documented by hepatic MRI

    PubMed Central

    Singh, Vasvi; Luthra, Saurav; Elajami, Tarec K; Welty, Francine K

    2015-01-01

    A 57-year-old Asian woman with type 2 diabetes mellitus, hypertension, obesity, dyslipidaemia and history of breast cancer, was referred to the cardiovascular health and lipid centre for evaluation and management of dyslipidaemia and NASH (Non-alcoholic steatohepatitis) in 2010. She originally had a detailed work up at the liver clinic for elevated liver enzymes, with no associated symptoms. Initial hepatic MRI on 22 January 2007 showed diffuse fatty infiltration quantitated at 15%. We counselled her on lifestyle modifications, including dietary measures and exercise, geared toward weight loss. Over the next 2 years, she lost 24.5 lbs; repeat hepatic MRI on 22 December 2011 showed 6% hepatic fat, which is within the normal range. This case demonstrates the efficacy of significant weight loss in the improvement and resolution of NASH. We believe that this is the first case report documenting this through liver MRI. PMID:25564638

  11. To Repeat or Not to Repeat a Course

    ERIC Educational Resources Information Center

    Armstrong, Michael J.; Biktimirov, Ernest N.

    2013-01-01

    The difficult transition from high school to university means that many students need to repeat (retake) 1 or more of their university courses. The authors examine the performance of students repeating first-year core courses in an undergraduate business program. They used data from university records for 116 students who took a total of 232…

  12. Procedural Learning and Associative Memory Mechanisms Contribute to Contextual Cueing: Evidence from fMRI and Eye-Tracking

    ERIC Educational Resources Information Center

    Manelis, Anna; Reder, Lynne M.

    2012-01-01

    Using a combination of eye tracking and fMRI in a contextual cueing task, we explored the mechanisms underlying the facilitation of visual search for repeated spatial configurations. When configurations of distractors were repeated, greater activation in the right hippocampus corresponded to greater reductions in the number of saccades to locate…

  13. Nifty Nines and Repeating Decimals

    ERIC Educational Resources Information Center

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  14. SU-E-J-192: Verification of 4D-MRI Internal Target Volume Using Cine MRI

    SciTech Connect

    Lafata, K; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J

    2014-06-01

    Purpose: To investigate the accuracy of 4D-MRI in determining the Internal Target Volume (ITV) used in radiation oncology treatment planning of liver cancers. Cine MRI is used as the standard baseline in establishing the feasibility and accuracy of 4D-MRI tumor motion within the liver. Methods: IRB approval was obtained for this retrospective study. Analysis was performed on MR images from four patients receiving external beam radiation therapy for liver cancer at our institution. Eligible patients received both Cine and 4D-MRI scans before treatment. Cine images were acquired sagittally in real time at a slice bisecting the tumor, while 4D images were acquired volumetrically. Cine MR DICOM headers were manipulated such that each respiratory frame was assigned a unique slice location. This approach permitted the treatment planning system (Eclipse, Varian Medical Systems) to recognize a complete respiratory cycle as a “volume”, where the gross tumor was contoured temporally. Software was developed to calculate the union of all frame contours in the structure set, resulting in the corresponding plane of the ITV projecting through the middle of the tumor, defined as the Internal Target Area (ITA). This was repeated for 4D-MRI, at the corresponding slice location, allowing a direct comparison of ITAs obtained from each modality. Results: Four patients have been analyzed. ITAs contoured from 4D-MRI correlate with contours from Cine MRI. The mean error of 4D values relative to Cine values is 7.67 +/− 2.55 %. No single ITA contoured from 4D-MRI demonstrated more than 10.5 % error compared to its Cine MRI counterpart. Conclusion: Motion management is a significant aspect of treatment planning within dynamic environments such as the liver, where diaphragmatic and cardiac activity influence plan accuracy. This small pilot study suggests that 4D-MRI based ITA measurements agree with Cine MRI based measurements, an important step towards clinical implementation. NIH 1R21

  15. All-photonic quantum repeaters

    NASA Astrophysics Data System (ADS)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-04-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories.

  16. Post-stroke aphasia recovery assessed with fMRI and a picture identification task

    PubMed Central

    Szaflarski, Jerzy P.; Eaton, Kenneth; Ball, Angel L.; Banks, Christi; Vannest, Jennifer; Allendorfer, Jane B.; Page, Stephen; Holland, Scott K.

    2010-01-01

    Background Stroke patients often display deficits in language function such as correctly naming objects. Our aim was to evaluate the reliability and the patterns of post-stroke language recovery using a picture identification task during fMRI at 4T. Material and Methods 4 healthy and 4 left MCA stroke subjects with chronic (>1 year) aphasia. Ten fMRI scans were performed for each subject over a 10-week period using a picture identification task. Active condition involved presenting subjects with a panel of 4 figures (e.g., drawings of 4 animals) every 6 seconds; subjects indicated which figure matched the written name in the center. Control condition was same/different judgment task of pairs of geometric figures (squares, octagons or combination) presented every 6 seconds. Thirty-second active/control blocks were repeated 5 times each; responses were recorded. Results Patients and controls exhibited similar demographic characteristics: age (46 vs. 53 years), personal handedness (EHI; 89 vs. 95), familial handedness (93 vs. 95) or years of education (14.3 vs. 14.8). For the active condition, controls performed better than patients (97.7% vs. 89.1%, p<0.001); performance was similar for the control condition (99.5% vs. 98.8%, p=0.23). During fMRI, controls exhibited bilateral, L>R positive blood oxygenation-level dependent (BOLD) activations in frontal and temporal language areas and symmetric retro-splenial and posterior cingulate areas and symmetric negative BOLD activations in bilateral fronto-temporal language networks. However, the patient group showed positive BOLD activations predominantly in peri-stroke areas and negative BOLD activations in the unaffected (right) hemisphere. Both the control and patient groups displayed high activation reliability (as measured by the ICC) in left frontal and temporal language areas, although the ICC in frontal regions of the patients was spread over a much larger peri-stroke area. Conclusion This study documents the utility

  17. Sodium MRI: Methods and applications

    PubMed Central

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

    2014-01-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

  18. Disclusion time measurement studies: stability of disclusion time--a 1-year follow-up.

    PubMed

    Kerstein, R

    1994-08-01

    Six of seven women were recalled after 1 year to remeasure their right- and left-side working disclusion times. Before the occlusal adjustment technique known as immediate complete anterior guidance development (ICAGD), these patients presented lengthy mean disclusion times (> 1.0 second) and multiple chronic myofascial pain dysfunction syndrome (MPDS) symptoms. After ICAGD, these patients presented with short mean disclusion times (< 0.7 second) and no chronic MPDS symptoms were observed. At 1-year follow-up, there was no statistical difference between present measurements of disclusion time and those of 1 year earlier. In addition, all six posttreatment patients demonstrated no observed chronic MPDS symptoms. However, the symptom of nocturnal bruxism appeared to recur with some chronic regularity. These results suggest that, for this population, disclusion time was stable over the 1-year period of observation, and the short disclusion time appears to allow normal daily muscle function with significantly lessened appearance of chronic myofacial pain dysfunction symptoms.

  19. Occupational exposure in MRI

    PubMed Central

    Mcrobbie, D W

    2012-01-01

    This article reviews occupational exposure in clinical MRI; it specifically considers units of exposure, basic physical interactions, health effects, guideline limits, dosimetry, results of exposure surveys, calculation of induced fields and the status of the European Physical Agents Directive. Electromagnetic field exposure in MRI from the static field B0, imaging gradients and radiofrequency transmission fields induces electric fields and currents in tissue, which are responsible for various acute sensory effects. The underlying theory and its application to the formulation of incident and induced field limits are presented. The recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) Bundesministerium für Arbeit und Soziales and Institute of Electrical and Electronics Engineers limits for incident field exposure are interpreted in a manner applicable to MRI. Field measurements show that exposure from movement within the B0 fringe field can exceed ICNIRP reference levels within 0.5 m of the bore entrance. Rate of change of field dB/dt from the imaging gradients is unlikely to exceed the new limits, although incident field limits can be exceeded for radiofrequency (RF) exposure within 0.2–0.5 m of the bore entrance. Dosimetric surveys of routine clinical practice show that staff are exposed to peak values of 42±24% of B0, with time-averaged exposures of 5.2±2.8 mT for magnets in the range 0.6–4 T. Exposure to time-varying fields arising from movement within the B0 fringe resulted in peak dB/dt of approximately 2 T s−1. Modelling of induced electric fields from the imaging gradients shows that ICNIRP-induced field limits are unlikely to be exceeded in most situations; however, movement through the static field may still present a problem. The likely application of the limits is discussed with respect to the reformulation of the European Union (EU) directive and its possible implications for MRI. PMID:22457400

  20. Quantum repeaters: fundamental and future

    NASA Astrophysics Data System (ADS)

    Li, Yue; Hua, Sha; Liu, Yu; Ye, Jun; Zhou, Quan

    2007-04-01

    An overview of the Quantum Repeater techniques based on Entanglement Distillation and Swapping is provided. Beginning with a brief history and the basic concepts of the quantum repeaters, the article primarily focuses on the communication model based on the quantum repeater techniques, which mainly consists of two fundamental modules --- the Entanglement Distillation module and the Swapping module. The realizations of Entanglement Distillation are discussed, including the Bernstein's Procrustean method, the Entanglement Concentration and the CNOT-purification method, etc. The schemes of implementing Swapping, which include the Swapping based on Bell-state measurement and the Swapping in Cavity QED, are also introduced. Then a comparison between these realizations and evaluations on them are presented. At last, the article discusses the experimental schemes of quantum repeaters at present, documents some remaining problems and emerging trends in this field.

  1. Repeatability in redundant manipulator systems

    NASA Astrophysics Data System (ADS)

    Mukherjee, Ranjan

    1994-02-01

    Terrestrial manipulators with more DOF than the dimension of the workspace and space manipulators with as many manipulator DOF as the dimension of the workspace are both redundant systems. An interesting problem of such redundant systems has been the repeatability problem due to the presence of nonholonomic constraints. We show, contrary to the existing belief, that integrability of the nonholonomic constraints is not a necessary condition for the repeatability of the configuration variables. There exist certain trajectories in the independent configuration variable space that are like 'holonomic loops' along which the redundant manipulators exhibit repeatable motion. We present a simple method based on optimization techniques for designing repeatable trajectories for free-flying space manipulators and terrestrial manipulators under pseudoinverse control.

  2. Protein Repeats from First Principles.

    PubMed

    Turjanski, Pablo; Parra, R Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U

    2016-04-05

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family.

  3. Protein Repeats from First Principles

    PubMed Central

    Turjanski, Pablo; Parra, R. Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U.

    2016-01-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family. PMID:27044676

  4. Nanospring behaviour of ankyrin repeats.

    PubMed

    Lee, Gwangrog; Abdi, Khadar; Jiang, Yong; Michaely, Peter; Bennett, Vann; Marszalek, Piotr E

    2006-03-09

    Ankyrin repeats are an amino-acid motif believed to function in protein recognition; they are present in tandem copies in diverse proteins in nearly all phyla. Ankyrin repeats contain antiparallel alpha-helices that can stack to form a superhelical spiral. Visual inspection of the extrapolated structure of 24 ankyrin-R repeats indicates the possibility of spring-like behaviour of the putative superhelix. Moreover, stacks of 17-29 ankyrin repeats in the cytoplasmic domains of transient receptor potential (TRP) channels have been identified as candidates for a spring that gates mechanoreceptors in hair cells as well as in Drosophila bristles. Here we report that tandem ankyrin repeats exhibit tertiary-structure-based elasticity and behave as a linear and fully reversible spring in single-molecule measurements by atomic force microscopy. We also observe an unexpected ability of unfolded repeats to generate force during refolding, and report the first direct measurement of the refolding force of a protein domain. Thus, we show that one of the most common amino-acid motifs has spring properties that could be important in mechanotransduction and in the design of nanodevices.

  5. Repeat endocarditis: analysis of risk factors based on the International Collaboration on Endocarditis - Prospective Cohort Study.

    PubMed

    Alagna, L; Park, L P; Nicholson, B P; Keiger, A J; Strahilevitz, J; Morris, A; Wray, D; Gordon, D; Delahaye, F; Edathodu, J; Miró, J M; Fernández-Hidalgo, N; Nacinovich, F M; Shahid, R; Woods, C W; Joyce, M J; Sexton, D J; Chu, V H

    2014-06-01

    Repeat episodes of infective endocarditis (IE) can occur in patients who survive an initial episode. We analysed risk factors and 1-year mortality of patients with repeat IE. We considered 1874 patients enrolled in the International Collaboration on Endocarditis - Prospective Cohort Study between January 2000 and December 2006 (ICE-PCS) who had definite native or prosthetic valve IE and 1-year follow-up. Multivariable analysis was used to determine risk factors for repeat IE and 1-year mortality. Of 1874 patients, 1783 (95.2%) had single-episode IE and 91 (4.8%) had repeat IE: 74/91 (81%) with new infection and 17/91 (19%) with presumed relapse. On bivariate analysis, repeat IE was associated with haemodialysis (p 0.002), HIV (p 0.009), injection drug use (IDU) (p < 0.001), Staphylococcus aureus IE (p 0.003), healthcare acquisition (p 0.006) and previous IE before ICE enrolment (p 0.001). On adjusted analysis, independent risk factors were haemodialysis (OR, 2.5; 95% CI, 1.2-5.3), IDU (OR, 2.9; 95% CI, 1.6-5.4), previous IE (OR, 2.8; 95% CI, 1.5-5.1) and living in the North American region (OR, 1.9; 95% CI, 1.1-3.4). Patients with repeat IE had higher 1-year mortality than those with single-episode IE (p 0.003). Repeat IE is associated with IDU, previous IE and haemodialysis. Clinicians should be aware of these risk factors in order to recognize patients who are at risk of repeat IE.

  6. Cyclic generalized projection MRI.

    PubMed

    Sarty, Gordon E

    2015-04-01

    Progress in the development of portable MRI hinges on the ability to use lightweight magnets that have non-uniform magnetic fields. An image encoding method and mathematical procedure for recovering the image from the NMR signal from non-uniform magnets with closed isomagnetic contours is given. Individual frequencies in an NMR signal from an object in a non-uniform magnetic field give rise to integrals of the object along contours of constant magnetic field: generalized projections. With closed isomagnetic field contours a simple, cyclic, direct reconstruction of the image from the generalized projections is possible when the magnet and RF transmit coil are held fixed relative to the imaged object while the RF receive coil moves. Numerical simulations, using the Shepp and Logan mathematical phantom, were completed to show that the mathematical method works and to illustrate numerical limitations. The method is numerically verified and exact reconstruction demonstrated for discrete mathematical image phantoms. Correct knowledge of the RF receive field is necessary or severe image distortions will result. The cyclic mathematical reconstruction method presented here will be useful for portable MRI schemes that use non-uniform magnets with closed isomagnetic contours along with mechanically or electronically moving the RF receive coils.

  7. MRI atlas of ectopic endometriosis.

    PubMed

    Dallaudière, B; Salut, C; Hummel, V; Pouquet, M; Piver, P; Rouanet, J-P; Maubon, A

    2013-03-01

    Ectopic endometriosis is a common condition which is often underdiagnosed, where MRI can help make a diagnosis simply, non-invasively and without irradiation. However, imagery signs of it are enormously polymorphic with a wide range of possible locations. In this paper, we have tried to illustrate comprehensively all its MRI appearances depending on the different locations where it occurs.

  8. MRI findings in Hirayama disease.

    PubMed

    Raval, Monali; Kumari, Rima; Dung, Aldrin Anthony Dung; Guglani, Bhuvnesh; Gupta, Nitij; Gupta, Rohit

    2010-11-01

    The objective of the study was to study the magnetic resonance imaging (MRI) features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA) sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7), abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30-40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

  9. The interaction between constituent year and within-1-year effects in elite German youth basketball.

    PubMed

    Steingröver, C; Wattie, N; Baker, J; Helsen, W F; Schorer, J

    2016-03-19

    The current state of research on relative age effects in basketball shows an uneven picture. These mixed results might be caused by the interaction of constituent year and within-year effects. Our aim was to examine constituent and within-1-year effects in elite German youth basketball. The sample (n = 4400) included players competing in the JBBL (Under-16 first division) and the NBBL (Under-19 first division) from 2011/2012 until 2013/2014. A multi-way frequency analysis revealed an interaction of constituent year effects and within-1-year effects for the JBBL, χ(2) (6, 2590) = 12.76, P < 0.05. NBBL data showed significant constituent year effects, χ(2) (2, n = 1810) = 25.32, P < 0.01, and within-1-year effects for all three age bands but no interaction. The interaction between constituent year and within-1-year effects in the JBBL showed reduced within-1-year effects with increasing age. Once players enter the system in the JBBL, relatively younger players seem less likely to drop out of the system. Results offer new insight regarding how the regulations of this talent development system may influence athletes' opportunities to enter the system and their likelihood of staying at the highest levels of competition.

  10. Segmentation precision of abdominal anatomy for MRI-based radiotherapy.

    PubMed

    Noel, Camille E; Zhu, Fan; Lee, Andrew Y; Yanle, Hu; Parikh, Parag J

    2014-01-01

    The limited soft tissue visualization provided by computed tomography, the standard imaging modality for radiotherapy treatment planning and daily localization, has motivated studies on the use of magnetic resonance imaging (MRI) for better characterization of treatment sites, such as the prostate and head and neck. However, no studies have been conducted on MRI-based segmentation for the abdomen, a site that could greatly benefit from enhanced soft tissue targeting. We investigated the interobserver and intraobserver precision in segmentation of abdominal organs on MR images for treatment planning and localization. Manual segmentation of 8 abdominal organs was performed by 3 independent observers on MR images acquired from 14 healthy subjects. Observers repeated segmentation 4 separate times for each image set. Interobserver and intraobserver contouring precision was assessed by computing 3-dimensional overlap (Dice coefficient [DC]) and distance to agreement (Hausdorff distance [HD]) of segmented organs. The mean and standard deviation of intraobserver and interobserver DC and HD values were DC(intraobserver) = 0.89 ± 0.12, HD(intraobserver) = 3.6mm ± 1.5, DC(interobserver) = 0.89 ± 0.15, and HD(interobserver) = 3.2mm ± 1.4. Overall, metrics indicated good interobserver/intraobserver precision (mean DC > 0.7, mean HD < 4mm). Results suggest that MRI offers good segmentation precision for abdominal sites. These findings support the utility of MRI for abdominal planning and localization, as emerging MRI technologies, techniques, and onboard imaging devices are beginning to enable MRI-based radiotherapy.

  11. Segmentation precision of abdominal anatomy for MRI-based radiotherapy

    SciTech Connect

    Noel, Camille E.; Zhu, Fan; Lee, Andrew Y.; Yanle, Hu; Parikh, Parag J.

    2014-10-01

    The limited soft tissue visualization provided by computed tomography, the standard imaging modality for radiotherapy treatment planning and daily localization, has motivated studies on the use of magnetic resonance imaging (MRI) for better characterization of treatment sites, such as the prostate and head and neck. However, no studies have been conducted on MRI-based segmentation for the abdomen, a site that could greatly benefit from enhanced soft tissue targeting. We investigated the interobserver and intraobserver precision in segmentation of abdominal organs on MR images for treatment planning and localization. Manual segmentation of 8 abdominal organs was performed by 3 independent observers on MR images acquired from 14 healthy subjects. Observers repeated segmentation 4 separate times for each image set. Interobserver and intraobserver contouring precision was assessed by computing 3-dimensional overlap (Dice coefficient [DC]) and distance to agreement (Hausdorff distance [HD]) of segmented organs. The mean and standard deviation of intraobserver and interobserver DC and HD values were DC{sub intraobserver} = 0.89 ± 0.12, HD{sub intraobserver} = 3.6 mm ± 1.5, DC{sub interobserver} = 0.89 ± 0.15, and HD{sub interobserver} = 3.2 mm ± 1.4. Overall, metrics indicated good interobserver/intraobserver precision (mean DC > 0.7, mean HD < 4 mm). Results suggest that MRI offers good segmentation precision for abdominal sites. These findings support the utility of MRI for abdominal planning and localization, as emerging MRI technologies, techniques, and onboard imaging devices are beginning to enable MRI-based radiotherapy.

  12. Limitations on quantum key repeaters.

    PubMed

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  13. Magnetars as soft gamma repeaters

    NASA Astrophysics Data System (ADS)

    O'Meara, Karen

    1999-05-01

    The source of non-periodic, repeating, gamma-ray bursts located within our galaxy and near supernova remnants has been a mystery. A new theory by Christopher Thompson and Robert Duncan, postulating the existence of young neutron stars with intense magnetic fields (1E14 Gauss or more) offers an explanation. The intense magnetic fields of these "magnetars" suffice to create the phenomena detected from soft gamma-ray repeaters. The poles of a magnetar are hot enough to emit steady, low level x-ray emissions. Stresses on the star's crust due to the drifting of the magnetic field through the superfluid core create seismic activity and "starquakes," which release enormous bursts of energy. Data collected from recent soft gamma-ray repeater bursts appear to be strong evidence in support of this exciting new theory.

  14. Limitations on quantum key repeaters

    NASA Astrophysics Data System (ADS)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-01

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  15. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    NASA Astrophysics Data System (ADS)

    Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

    2014-02-01

    The Gd5Ge2Si2 alloy and the off-stoichiometric Ni50Mn35In15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd5Ge2Si2 and Ni50Mn35In15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  16. "I was born full deaf." Written language outcomes after 1 year of strategic and interactive writing instruction.

    PubMed

    Wolbers, Kimberly A; Dostal, Hannah M; Bowers, Lisa M

    2012-01-01

    Nonstandard grammatical forms are often present in the writing of deaf students that are rarely, if ever, seen in the writing of hearing students. With the implementation of Strategic and Interactive Writing Instruction (SIWI) in previous studies, students have demonstrated significant gains in high-level writing skills (e.g., text structure) but have also made gains with English grammar skills. This 1-year study expands on prior research by longitudinally examining the written language growth (i.e., writing length, sentence complexity, sentence awareness, and function words) of 29 deaf middle-school students. A repeated-measures analysis of variance with a between-subjects variable for literacy achievement level was used to examine gains over time and the intervention's efficacy when used with students of various literacy levels. Students, whether high or low achieving, demonstrated statistically significant gains with writing length, sentence complexity, and sentence awareness. Subordinate clauses were found to be an area of difficulty, and follow up strategies are suggested. An analysis of function word data, specifically prepositions and articles, revealed different patterns of written language growth by language group (e.g., American Sign Language users, oral students, users of English-based sign).

  17. PTSD among a treatment sample of repeat DUI offenders.

    PubMed

    Peller, Allyson J; Najavits, Lisa M; Nelson, Sarah E; LaBrie, Richard A; Shaffer, Howard J

    2010-08-01

    Recent studies indicate that posttraumatic stress disorder (PTSD) is one of the most common psychiatric comorbidities among driving-under-the-influence (DUI) offenders in treatment. Investigation of DUI offenders' PTSD and clinical characteristics could have important implications for prevention and treatment. This prospective study examined the demographic and clinical characteristics of repeat DUI offenders with PTSD symptoms at baseline and 1-year follow-up. Seven hundred twenty-nine DUI offenders admitted to a 2-week inpatient program participated in the study. Participants with PTSD evidenced more severe psychiatric comorbidity and reported a higher DUI recidivism rate at 1-year than those without PTSD. This study suggests a need to address PTSD among DUI offenders, as well as to further develop methodologies for accurately reporting DUI recidivism.

  18. Economic evaluation and 1-year survival analysis of MARS in patients with alcoholic liver disease.

    PubMed

    Hessel, Franz P; Mitzner, Steffen R; Rief, Jana; Guellstorff, Britta; Steiner, Susanne; Wasem, Jürgen

    2003-01-01

    Objective of this study was to determine 1-year survival, costs and cost-effectiveness of the artificial liver support system Molecular Adsorbent Recirculating System (MARS) in patients with acute-on-chronic liver failure (ACLF) and an underlying alcoholic liver disease. In a case-control study, 13 patients treated with MARS were compared to 23 controls of similar age, sex and severity of disease. Inpatient hospital costs data were extracted from patients' files and hospital's internal costing. Patients and treating GPs were contacted, thus determining resource use and survival 1-year after treatment. Mean 1-year survival time in MARS group was 261 days and 148 days in controls. Kaplan-Meier analysis shows advantages of MARS patients (Logrank: P=0.057). Direct medical costs per patient for initial hospital stay and 1-year follow-up from a payer's perspective were Euro 18,792 for MARS patients and Euro 9638 for controls. The costs per life-year gained are Euro 29,719 (time horizon 1 year). From a societal perspective, the numbers are higher (costs per life-year gained: Euro 79,075), mainly because of the fact that there is no regular reimbursement of MARS and therefore intervention costs were not calculated from payer's perspective. A trade-off between medical benefit and higher costs has to be made, but 1-year results suggest an acceptable cost-effectiveness of MARS. Prolonging the time horizon and including indirect costs, which will be done in future research, would probably improve cost-effectiveness.

  19. Evaluation of the management of Hr-HPV+/PapTest- women: results at 1-year recall.

    PubMed

    Chiappetta, Caterina; Puggioni, Chiara; Lendaro, Eugenio; Cacciotti, Jessica; Zaralli, Roberto; Migliore, Giovanna; Bellardini, Paola; Petrozza, Vincenzo; Della Rocca, Carlo; Di Cristofano, Claudio

    2015-01-01

    With cervical cancer screening the choice of 1-year as a period of follow-up in positive high-risk HPV women without cytological lesions is still under discussion. We evaluated the management of these women and the role of HPV genotyping test. We did a cervical cancer screening study of women aged 35-64 with primary high-risk HPV test. Women positive for high-risk HPV with negative cytology were followed-up after 1 year. In this study we selected women with high-risk HPV+/PapTest- resulted high-risk HPV+ at recall and performed the PapTest and HPV genotyping test. The detection rate of squamous high grade (CIN2+) relative to the total screened cohort was 2.1‰, and it was 0.2‰ at the 1-year recall. The colposcopy performed in women referred at the 1-year recall accounted for 48.8% of the total (baseline + 1-year recall), and 84.3% of these women had no cytological lesions. The most frequent hr-HPV genotype detected was HPV16 and 66.7% of co-infections were due to HPV16 and HPV18. 54.5% of women presented a persistent infection at 1-year recall with the same HPV subtype, 50% of persistent infections was due to HPV16 and 16.7% of these were determined to be CIN2+ histological lesions. Our data show that it may be useful to extend the period of follow-up for women hr-HPV+/PapTest- so as to reduce the number of unnecessary colposcopies due to the transitory infections and that the genotyping test could help to identify the persistent infections in which HPV16 is involved.

  20. XEN Glaucoma Implant with Mitomycin C 1-Year Follow-Up: Result and Complications

    PubMed Central

    Bilgic, Alper; Eltanamly, Rasha

    2017-01-01

    Purpose. To evaluate gel microstent (XEN, Aquesys, Inc) for treatment of primary open angle glaucoma (POAG). Methods. In this prospective interventional study, 13 eyes with POAG underwent XEN implantation with subconjunctival mitomycin-C. Of those eyes, 3 were pseudophakic and 10 underwent simultaneous phacoemulsification and XEN. Patients had uncontrolled IOP, had intolerance to therapy, or had maximal therapy but undergoing cataract extraction. Follow-up visits included IOP, number of medications, vision, and complications and lasted for 1 year. Complete success was defined as IOP reduction ≥20% from preoperative baseline at 1 year without any glaucoma medications while partial success as IOP reduction of ≥20% at 1 year with medications. Results. IOP dropped from 16 ± 4 mmHg pre-op to 9 ± 5, 11 ± 6, 12 ± 5, 12 ± 4, and 12 ± 3 mmHg at 1 week, 1, 3, 6, and 12 months (p = 0.004, 0.026, 0.034, 0.01, and 0.01, Wilcoxon Signed Ranks) consecutively. BCVA (LogMAR) was 0.33 ± 0.34 and improved to 0.13 ± 0.11 at 1 year. Mean number of medications dropped from 1.9 ± 1 preoperatively to 0.3 ± 0.49 (p = 0.003) at 1 year. 42% of eyes achieved complete success and 66% qualified success. Complications included choroidal detachment in 2 eyes, and implant extrusion in 1 eye, and 2 eyes underwent trabeculectomy. Conclusion. XEN implant is an effective surgical treatment for POAG, with significant reduction in IOP and glaucoma medications at 1 year follow-up. PMID:28348884

  1. MRI of plants and foods.

    PubMed

    Van As, Henk; van Duynhoven, John

    2013-04-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by complex multiple length scale architectures. Intact plants have an additional level of complexity since they are living systems which critically depend on transport and signalling processes between and within tissues and organs. The combination of recent cutting-edge technical advances and integration of MRI accessible parameters has the perspective to contribute to breakthroughs in understanding complex regulatory plant performance mechanisms. In food science and technology MRI allows for quantitative multi-length scale structural assessment of food systems, non-invasive monitoring of heat and mass transport during shelf-life and processing, and for a unique view on food properties under shear. These MRI applications are powerful enablers of rationally (re)designed food formulations and processes. Limitations and bottlenecks of the present plant and food MRI methods are mainly related to short T2 values and susceptibility artefacts originating from small air spaces in tissues/materials. We envisage cross-fertilisation of solutions to overcome these hurdles in MRI applications in plants and foods. For both application areas we witness a development where MRI is moving from highly specialised equipment to mobile and downscaled versions to be used by a broad user base in the field, greenhouse, food laboratory or factory.

  2. MRI in ocular drug delivery

    PubMed Central

    Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

    2008-01-01

    Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed. PMID:18186077

  3. Simultaneous segmentation and registration of contrast-enhanced breast MRI.

    PubMed

    Xiaohua, Chen; Brady, Michael; Lo, Jonathan Lok-Chuen; Moore, Niall

    2005-01-01

    Breast Contrast-Enhanced MRI (ce-MRI) requires a series of images to be acquired before, and repeatedly after, intravenous injection of a contrast agent. Breast MRI segmentation based on the differential enhancement of image intensities can assist the clinician detect suspicious regions. Image registration between the temporal data sets is necessary to compensate for patient motion, which is quite often substantial. Although segmentation and registration are usually treated as separate problems in medical image analysis, they can naturally benefit a great deal from each other. In this paper, we propose a scheme for simultaneous segmentation and registration of breast ce-MRI. It is developed within a Bayesian framework, based on a maximum a posteriori estimation method. A pharmacokinetic model and Markov Random Field model have been incorporated into the framework in order to improve the performance of our algorithm. Our method has been applied to the segmentation and registration of clinical ce-MR images. The results show the potential of our methodology to extract useful information for breast cancer detection.

  4. Short-term repeatability of joint space width measurements using a magnetic resonance imaging compatible knee positioning device.

    PubMed

    Koff, M F; Stanley, D W; Weishaar, P J; Amrami, K K; Kaufman, K R

    2010-01-01

    The purpose of this study was to evaluate a magnetic resonance imaging (MRI) compatible knee positioning device to aid in minimizing intratechnologist and intertechnologist differences of minimum joint space width (JSW) measurements. Five subjects were scanned by two separate technologists, with and without an MRI-compatible positioning device. A semi-automated program calculated the minimum JSW of the tibiofemoral and patellofemoral joints. The scan-to-scan repeatability was evaluated from measurements between serial scans without subject repositioning, and the intratechnologist and intertechnologist repeatabilities were evaluated when the subject was removed from the magnet and repositioned by an individual technologist. The root mean square (RMS) error of the JSW measurements was also calculated. All measures of scan-to-scan repeatability and intratechnologist repeatability were unchanged with the MRI-compatible positioning device. The intertechnologist repeatability decreased from 0.70 to 0.42 mm, and the RMS error was significantly reduced (P = 0.0006) from 0.26 to 0.15 mm for the tibiofemoral joint. The variability of patellofemoral JSW measurements increased when using the positioning device; however, the increases were not statistically significant. The intertechnologist repeatability increased from 1.55 to 1.79 mm, and the RMS error increased from 0.58 to 0.73 mm. The MRI-compatible positioning device was successful at reducing JSW measurement variability at the tibiofemoral joint. The increase in measurement variability at the patellofemoral joint may be due to local incongruities of the articular surfaces. An MRI-compatible positioning device may be beneficial for quantitative longitudinal studies evaluating knee joint health.

  5. MRI Meets MPI: a bimodal MPI-MRI tomograph.

    PubMed

    Vogel, Patrick; Lother, Steffen; Rückert, Martin A; Kullmann, Walter H; Jakob, Peter M; Fidler, Florian; Behr, Volker C

    2014-10-01

    While magnetic particle imaging (MPI) constitutes a novel biomedical imaging technique for tracking superparamagnetic nanoparticles in vivo, unlike magnetic resonance imaging (MRI), it cannot provide anatomical background information. Until now these two modalities have been performed in separate scanners and image co-registration has been hampered by the need to reposition the sample in both systems as similarly as possible. This paper presents a bimodal MPI-MRI-tomograph that combines both modalities in a single system.MPI and MRI images can thus be acquired without moving the sample or replacing any parts in the setup. The images acquired with the presented setup show excellent agreement between the localization of the nanoparticles in MPI and the MRI background data. A combination of two highly complementary imaging modalities has been achieved.

  6. MRI Technologies in Recent Human Brain Mapping

    NASA Astrophysics Data System (ADS)

    Sasaki, Yuka

    The recent magnetic resonance imaging (MRI) technology and techniques used in human brain mapping are remarkable. They are getting, faster, stronger and better. The advanced MRI technologies and techniques include, but not to limited to, the magnetic resonance imaging at higher magnetic field strengths, diffusion tensor imaging, multimodal neuroimaging, and monkey functional MRI. In this article, these advanced MRI techniques are briefly overviewed.

  7. Do Twelfths Terminate or Repeat?

    ERIC Educational Resources Information Center

    Ambrose, Rebecca; Burnison, Erica

    2015-01-01

    When finding the decimal equivalent of a fraction with 12 in the denominator, will it terminate or repeat? This question came from a seventh grader in author Erica Burnison's class as the student was pondering a poster generated by one of her classmates. Not only was the question intriguing, but it also affirmed the belief in the power of…

  8. Mechanical Anisotropy of Ankyrin Repeats

    PubMed Central

    Lee, Whasil; Zeng, Xiancheng; Rotolo, Kristina; Yang, Ming; Schofield, Christopher J.; Bennett, Vann; Yang, Weitao; Marszalek, Piotr E.

    2012-01-01

    Red blood cells are frequently deformed and their cytoskeletal proteins such as spectrin and ankyrin-R are repeatedly subjected to mechanical forces. While the mechanics of spectrin was thoroughly investigated in vitro and in vivo, little is known about the mechanical behavior of ankyrin-R. In this study, we combine coarse-grained steered molecular dynamics simulations and atomic force spectroscopy to examine the mechanical response of ankyrin repeats (ARs) in a model synthetic AR protein NI6C, and in the D34 fragment of native ankyrin-R when these proteins are subjected to various stretching geometry conditions. Our steered molecular dynamics results, supported by AFM measurements, reveal an unusual mechanical anisotropy of ARs: their mechanical stability is greater when their unfolding is forced to propagate from the N-terminus toward the C-terminus (repeats unfold at ∼60 pN), as compared to the unfolding in the opposite direction (unfolding force ∼ 30 pN). This anisotropy is also reflected in the complex refolding behavior of ARs. The origin of this unfolding and refolding anisotropy is in the various numbers of native contacts that are broken and formed at the interfaces between neighboring repeats depending on the unfolding/refolding propagation directions. Finally, we discuss how these complex mechanical properties of ARs in D34 may affect its behavior in vivo. PMID:22404934

  9. Pentapeptide Repeat Proteins and Cyanobacteria

    SciTech Connect

    Buchko, Garry W.

    2009-10-16

    Cyanobacteria are unique in many ways and one unusual feature is the presence of a suite of proteins that contain at least one domain with a minimum of eight tandem repeated five-residues (Rfr) of the general consensus sequence A[N/D]LXX. The function of such pentapeptide repeat proteins (PRPs) are still unknown, however, their prevalence in cyanobacteria suggests that they may play some role in the unique biological activities of cyanobacteria. As part of an inter-disciplinary Membrane Biology Grand Challenge at the Environmental Molecular Sciences Laboratory (Pacific Northwest National Laboratory) and Washington University in St. Louis, the genome of Cyanothece 51142 was sequenced and its molecular biology studied with relation to circadian rhythms. The genome of Cyanothece encodes for 35 proteins that contain at least one PRP domain. These proteins range in size from 105 (Cce_3102) to 930 (Cce_2929) kDa with the PRP domains ranging in predicted size from 12 (Cce_1545) to 62 (cce_3979) tandem pentapeptide repeats. Transcriptomic studies with 29 out of the 35 genes showed that at least three of the PRPs in Cyanothece 51142 (cce_0029, cce_3083, and cce_3272) oscillated with repeated periods of light and dark, further supporting a biological function for PRPs. Using X-ray diffraction crystallography, the structure for two pentapeptide repeat proteins from Cyanothece 51142 were determined, cce_1272 (aka Rfr32) and cce_4529 (aka Rfr23). Analysis of their molecular structures suggests that all PRP may share the same structural motif, a novel type of right-handed quadrilateral β-helix, or Rfr-fold, reminiscent of a square tower with four distinct faces. Each pentapeptide repeat occupies one face of the Rfr-fold with four consecutive pentapeptide repeats completing a coil that, in turn, stack upon each other to form “protein skyscrapers”. Details of the structural features of the Rfr-fold are reviewed here together with a discussion for the possible role of end

  10. An Analysis of 1-Year Impacts of Youth Transition Demonstration Projects

    ERIC Educational Resources Information Center

    Fraker, Thomas M.; Luecking, Richard G.; Mamun, Arif A.; Martinez, John M.; Reed, Deborah S.; Wittenburg, David C.

    2016-01-01

    This article examines the impacts of the Youth Transition Demonstration, an initiative of the Social Security Administration (SSA) to improve employment outcomes for youth with disabilities. Based on a random assignment design, the analysis uses data from a 1-year follow-up survey and SSA administrative records for 5,203 youth in six research…

  11. Latent Classes of Adolescent Posttraumatic Stress Disorder Predict Functioning and Disorder after 1 Year

    ERIC Educational Resources Information Center

    Ayer, Lynsay; Danielson, Carla Kmett; Amstadter, Ananda B.; Ruggiero, Ken; Saunders, Ben; Kilpatrick, Dean

    2011-01-01

    Objective: To identify latent classes of posttraumatic stress disorder (PTSD) symptoms in a national sample of adolescents, and to test their associations with PTSD and functional impairment 1 year later. Method: A total of 1,119 trauma-exposed youth aged 12 through 17 years (mean = 14.99 years, 51% female and 49% male) participating in the…

  12. Colles' fracture treated with non-bridging external fixation: a 1-year follow-up.

    PubMed

    Andersen, J K; Høgh, A; Gantov, J; Vaesel, M T; Hansen, T Baek

    2009-08-01

    The results in 75 of 105 patients with Older type II/III (AO type A2.2, A3.1, A3.2) Colles' fractures, treated with non-bridging external fixation are presented. The mean age was 67.8 years, and all patients were followed prospectively for 12 months with radiological and functional assessment. No statistically significant loss of radial length, angulation or inclination was seen between the postoperative reduction and the 1-year follow-up examination. The clinical results after 1 year were 66 (88%) excellent/good, nine (12%) fair and 0 (0%) poor according to the modified Gartland and Werley score. Mean visual analogue scale pain score after 1 year was 0.8. In three patients (4%), re-displacement of the fracture occurred and was treated with plating. Non-bridging external fixation offers a reliable method of maintaining radiological reduction of Older type II/III fractures of the distal radius and gives a good functional outcome after 1 year.

  13. Verbal Labels Modulate Perceptual Object Processing in 1-Year-Old Children

    ERIC Educational Resources Information Center

    Gliga, Teodora; Volein, Agnes; Csibra, Gergely

    2010-01-01

    Whether verbal labels help infants visually process and categorize objects is a contentious issue. Using electroencephalography, we investigated whether possessing familiar or novel labels for objects directly enhances 1-year-old children's neural processes underlying the perception of those objects. We found enhanced gamma-band (20-60 Hz)…

  14. The Stability and Structure of Career Decision-Making Profiles: A 1-Year Follow-Up

    ERIC Educational Resources Information Center

    Gati, Itamar; Levin, Nimrod

    2012-01-01

    The Career Decision-Making Profile (CDMP) questionnaire is a multidimensional measure of the way individuals make career decisions, developed as an alternative to the single, most-dominant trait approach. Using a sample of freshmen students, the 2-week reliability (N = 273) and 1-year stability (N = 182) of the CDMP was tested for each of the 12…

  15. 29 CFR 2530.204-1 - Year of participation for benefit accrual.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ADMINISTRATION, DEPARTMENT OF LABOR MINIMUM STANDARDS FOR EMPLOYEE PENSION BENEFIT PLANS UNDER THE EMPLOYEE... BENEFIT PLANS Participation, Vesting and Benefit Accrual § 2530.204-1 Year of participation for benefit... requirements relating to benefit accrual under a defined benefit pension plan. Some of these requirements...

  16. Thai Adolescent Survivors 1 Year after the 2004 Tsunami: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Tuicomepee, Arunya; Romano, John L.

    2008-01-01

    This study examined the impact of the 2004 Asian tsunami on 400 Thai adolescents 1 year after the disaster. Quantitative analyses showed that youth behavior problems were positively associated with tsunami experiences and negatively associated with positive family functioning. Tsunami exposure, school connectedness, religious beliefs and…

  17. Dialectical Behavior Therapy for Adolescents with Bipolar Disorder: A 1-Year Open Trial

    ERIC Educational Resources Information Center

    Goldstein, Tina R.; Axelson, David A.; Birmaher, Boris; Brent, David A.

    2007-01-01

    Objective: To describe an adapted version of dialectical behavior therapy for adolescents with bipolar disorder. Method: The dialectical behavior therapy intervention is delivered over 1 year and consists of two modalities: family skills training (conducted with individual family units) and individual therapy. The acute treatment period (6 months)…

  18. A Program To Promote Positive Body Image: A 1-Year Follow-Up Evaluation.

    ERIC Educational Resources Information Center

    McVey, Gail L.; Davis, Ron

    2002-01-01

    Evaluated the effectiveness of a program designed to promote body image satisfaction and prevent eating problems in young adolescent girls over a 1-year period. Found no program effect. Found instead, significant increases in body image satisfaction and decreases in eating problem scores over time for participants in both the prevention and…

  19. Outpatient treated burns in infants younger than 1 year in Helsinki during 2005-2009.

    PubMed

    Laitakari, Elina; Koljonen, Virve; Pyörälä, Sari; Rintala, Risto

    2014-05-01

    In general, voluminous data exists concerning burns in children, but the data focusing specially on children less than 1 year of age is sporadic. We therefore focused on examining the special features of burns in children less than 1 year of age. A retrospective study of all outpatient treated burn patients <1 year old at the Hospital for Children and Adolescents, Helsinki, Finland, from January 2005 to December 2009 was performed. During the 5-year period we identified 106 outpatient treated infants with burns, representing 15% of all pediatric burns during the study period. The majority was male and aged 9-12 months. Most of the burns occurred at home, and in most cases a caregiver was present in the injury room. Scalds were the most common type of injury followed by contact burns. The most common source of scald was from cups containing hot drink, and the most common source of contact burn was hot stoves or oven doors. Special attention needs to be targeted toward the prevention of burns in children less than 1 year of age. The majority of the injuries could have been prevented with more vigilance.

  20. Relationship between tongue strength and 1-year life expectancy in elderly people needing nursing care.

    PubMed

    Yajima, Yuri; Kikutani, Takeshi; Tamura, Fumiyo; Yoshida, Mitsuyoshi

    2017-01-05

    Tongue strength is a useful indicator of oral function and has been found to decrease with aging and reduced physical functioning. The present study aimed to assess the relationships of tongue strength with physical function, mental function, and nutritional status, and also between these factors and 1-year outcomes, to determine whether tongue strength is related to life expectancy in elderly people needing nursing care. The subjects were 140 elderly individuals requiring needing nursing care (49 men and 91 women; ≥65 years). The investigated items included sex, age, activities of daily living (ADL), comorbidity, cognitive function, nutritional status, eating function, occlusal support, and tongue strength. Furthermore, a follow-up study was conducted 1 year later, and factors related to death were identified. The mean tongue strength of the total 140 subjects was 20.3 ± 8.6 kPa. Tongue strength was assessed relative to each of the investigated items, using the t test and one-way analysis of variance. Tongue strength was significantly related to ADL, comorbidity, cognitive function, calf circumference, food intake, and occlusal support. Fifteen subjects were found to have died at the 1-year follow-up study. We assessed the relationships of 1-year outcomes with each of the factors examined, and 1-year outcomes were found to be significantly related to ADL and tongue strength.

  1. [Standartization of MRI studies in multiple sclerosis].

    PubMed

    Bryukhov, V V; Krotenkova, I A; Morozova, S N; Krotenkova, M V

    2016-01-01

    The use of magnetic resonance imaging (MRI) in patients with multiple sclerosis has markedly increased in recent years. The main task of the MRI studies after the diagnosis of multiple sclerosis is to assess the dynamics of MRI for determining disease progression and monitoring the efficacy of therapy. In this regard, it is very important to obtain the most identical baseline and follow-up MRI that is possible when a single standard protocol is used. This article presents the protocol of brain MRI and spinal cord MRI and interpretation of MRI studies in patients with multiple sclerosis.

  2. [Repeated head injury during judo practice].

    PubMed

    Fujiwara, Kazue

    2014-01-01

    Mild traumatic brain injuries, if repeated, can cause permanent brain damage, or even death. I examined five published documents(three judicial decisions, one official injury report, and one book)to analyze incidents in which high school students who, while practicing judo, experienced acute subdural hematoma(ASDH)with grave outcomes, despite the fact that they had been examined by neurosurgeons. The five students, first-grade boy and girl of junior high school and two first-grade boys and one second-grade girl of senior high school, were hit on the head during extracurricular judo practice and were taken to the neurosurgery department of different hospitals. They were all novices or unskilled players. The initial diagnoses were ASDH in three cases, concussion in one, and headache in one. Although the surgeons, except in one case, prohibited the students from returning to play, the juveniles resumed judo practice soon. Some of them complained of continued headaches, but they kept practicing. Between 17 and 82 days after the first injury, they received the fateful hits to their heads, and they were brought to the emergency rooms. MRI and CT revealed ASDH in all;two of them died, and the other three remain in persistent vegetative state. Neurosurgeons should take the initiative to prevent severe brain injury of young athletes through collaborations with the athletes themselves, fellow athletes, family members, coaches, teachers, athletic directors, and other physicians. They should pay close attention to headaches and other signs and symptoms of concussion and prohibit the athletes from returning to play until they are confirmed to be symptom free for recommended periods, insisting that safety comes first.

  3. Arteriovenous fistula complication following MRI

    PubMed Central

    Kirkman, Danielle; Junglee, Naushad; Mullins, Paul; Macdonald, Jamie Hugo

    2012-01-01

    Health professionals should be aware of medical procedures that cause vascular access complications. This case describes a haemodialysis patient who experienced pain, swelling and bruising over a radiocephalic fistula following MRI. Exactly the same signs and symptoms were evident following a second scan performed 3 months later. Plausible explanations include a radio frequency-induced electrical current being formed at the arteriovenous fistula, or varying gradients of the MRI sequence stimulating peripheral nerves, leading to a site of increased tissue stimulation. Of note, a juxta-anastomotic venous stenosis was confirmed by fistulogram 4 days after the second scan, although whether this access failure was due to the MRI scan per se could not be ascertained. Nevertheless, these previously undocumented observations suggest that careful patient and fistula monitoring is required when completing MRI scans in those with an arteriovenous fistula. PMID:22927271

  4. MRI of the Musculoskeletal System

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  5. Magnetic Resonance Imaging (MRI) - Spine

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  6. Magnetic Resonance Imaging (MRI) -- Head

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  7. Magnetic Resonance Imaging (MRI) Safety

    MedlinePlus

    ... radiation. Instead, MRI uses a powerful magnetic field, radio waves, rapidly changing magnetic fields, and a computer to ... in most of the body's tissues. The applied radio waves then cause these protons to produce signals that ...

  8. A tonsillolith seen on MRI.

    PubMed

    el-Sherif, I; Shembesh, F M

    1997-01-01

    A case of a large tonsillolith visualized by magnetic resonance imaging is presented. Although otolaryngologists are well aware of this entity, few radiologists are. The importance of distinguishing tonsilloliths from other structures by MRI is discussed.

  9. Spiritual absence and 1-year mortality after hematopoietic stem cell transplant.

    PubMed

    Pereira, Deidre B; Christian, Lisa M; Patidar, Seema; Bishop, Michelle M; Dodd, Stacy M; Athanason, Rebecca; Wingard, John R; Reddy, Vijay S

    2010-08-01

    Religiosity and spirituality have been associated with better survival in large epidemiologic studies. This study examined the relationship between spiritual absence and 1-year all-cause mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Depression and problematic compliance were examined as possible mediators of a significant spiritual absence-mortality relationship. Eighty-five adults (mean = 46.85 years old, SD = 11.90 years) undergoing evaluation for allogeneic HSCT had routine psychologie evaluation prior to HSCT admission. The Millon Behavioral Medicine Diagnostic was used to assess spiritual absence, depression, and problematic compliance, the psychosocial predictors of interest. Patient status at 1 year and survival time in days were abstracted from medical records. Cox regression analysis was used to examine the relationship between the psychosocial factors of interest and mortality after adjusting for relevant biobehavioral factors. Twenty-nine percent (n = 25) of participants died within 1 year of HSCT. After covarying for disease type, individuals with the highest spiritual absence and problematic compliance scores were significantly more likely to die 1-year post-HSCT (hazard ratio [HR] = 2.49, P = .043 and HR = 3.74, P = .029, respectively), particularly secondary to infection, sepsis, or graft-versus-host disease (GVHD) (HR = 4.56, P = .01 and HR = 5.61, P = .014), relative to those without elevations on these scales. Depression was not associated with 1-year mortality, and problematic compliance did not mediate the relationship between spiritual absence and mortality. These preliminary results suggest that both spiritual absence and problematic compliance may be associated with poorer survival following HSCT. Future research should examine these relations in a larger sample using a more comprehensive assessment of spirituality.

  10. Endoscopic sleeve gastroplasty with 1-year follow-up: factors predictive of success

    PubMed Central

    Lopez-Nava, G.; Galvao, M.; Bautista-Castaño, I.; Fernandez-Corbelle, J. P.; Trell, M.

    2016-01-01

    Background and study aims: Bariatric endoscopy has emerged as an aid in the nonsurgical treatment of obesity. The objective of this study is to critically provide the results and follow-up of endoscopic sleeve gastroplasty 1 year after the procedure. Patients and methods: Prospective single-center follow-up study of 25 patients (5 men, 20 women) who underwent flexible endoscopic suturing for endoluminal gastric volume reduction. A multidisciplinary team provided post-procedure care. Patient outcomes were recorded at 1 year after the procedure. Linear regression analysis was done to evaluate the variables associated with best results at 1 year of follow-up. Results: Mean body mass index (BMI) was 38.5 ± 4.6 kg/m2 (range 30 – 47) and mean age 44.5 ± 8.2 years (range 29 – 60). At 1 year, 22 patients continued with the follow-up (2 dropped out at 6 months and 1 at 3 months). There were no major intra-procedural, early, or delayed adverse events. Mean BMI loss was 7.3 ± 4.2 kg/m2, and mean percentage of total body weight loss was 18.7 ± 10.7 at 1 year. In the linear regression analysis, adjusted by initial BMI, variables associated with %TBWL involved the frequency of nutritional (β = 0.563, P = 0.014) and psychological contacts (β = 0.727, P = 0.025). The number of nutritional and psychological contacts were predictive of good weight loss results. Conclusions: Endoscopic sleeve gastroplasty is a feasible, reproducible, and effective procedure to treat obesity. Nutritional and psychological interaction are predictive of success. PMID:26878054

  11. Understanding Trends in Kidney Function 1 Year after Kidney Transplant in the United States.

    PubMed

    Huang, Yihung; Tilea, Anca; Gillespie, Brenda; Shahinian, Vahakn; Banerjee, Tanushree; Grubbs, Vanessa; Powe, Neil; Rios-Burrows, Nilka; Pavkov, Meda; Saran, Rajiv

    2017-03-07

    Lower eGFR 1 year after kidney transplant is associated with shorter allograft and patient survival. We examined how practice changes in the past decade correlated with time trends in average eGFR at 1 year after kidney transplant in the United States in a cohort of 189,944 patients who received a kidney transplant between 2001 and 2013. We calculated the average eGFR at 1 year after transplant for the recipient cohort of each year using the appropriate Modification of Diet in Renal Disease equation depending on the prevailing methodology of creatinine measurement, and used linear regression to model the effects of practice changes on the national post-transplant eGFR trend. Between the 2001-2005 period and the 2011-2013 period, average 1-year post-transplant eGFR remained essentially unchanged, with differences of 1.34 (95% confidence interval, 1.03 to 1.65) ml/min per 1.73 m(2) and 0.66 (95% confidence interval, 0.32 to 1.01) ml/min per 1.73 m(2) among deceased and living donor kidney transplant recipients, respectively. Over time, the mean age of recipients increased and more marginal organs were used; adjusting for these trends unmasked a larger temporal improvement in post-transplant eGFR. However, changes in immunosuppression practice had a positive effect on average post-transplant eGFR and balanced out the negative effect of recipient/donor characteristics. In conclusion, average 1-year post-transplant eGFR remained stable, despite increasingly unfavorable attributes in recipients and donors. With an aging ESRD population and continued organ shortage, preservation of average post-transplant eGFR will require sustained improvement in immunosuppression and other aspects of post-transplant care.

  12. Effect of Peritoneal Dialysis Modality on the 1-Year Rate of Decline of Residual Renal Function

    PubMed Central

    Kim, Chan Ho; Oh, Hyung Jung; Lee, Mi Jung; Kwon, Young Eun; Kim, Yung Ly; Nam, Ki Heon; Park, Kyoung Sook; An, Seong Yeong; Ko, Kwang Il; Koo, Hyang Mo; Doh, Fa Mee; Han, Seung Hyeok; Yoo, Tae-Hyun; Kim, Beom Seok; Kang, Shin-Wook

    2014-01-01

    Purpose The effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort. Materials and Methods We conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation. Results The RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m2 in CCPD patients and 3.63±3.67 mL/min/1.73 m2 in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m2 in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052). Conclusion Our results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities. PMID:24339299

  13. Potential Clinical Applications for Spinal Functional MRI

    PubMed Central

    Kornelsen, Jennifer; Mackey, Sean

    2010-01-01

    Functional MRI (fMRI) of the spinal cord is a noninvasive technique for obtaining information regarding spinal cord neuronal function. This article provides a brief overview of recent developments in spinal cord fMRI and outlines potential applications, as well as the limitations that must be overcome, for using spinal fMRI in the clinic. This technique is currently used for research purposes, but significant potential exists for spinal fMRI to become an important clinical tool. PMID:17504642

  14. [Recent advances in newborn MRI].

    PubMed

    Morel, B; Hornoy, P; Husson, B; Bloch, I; Adamsbaum, C

    2014-07-01

    The accurate morphological exploration of the brain is a major challenge in neonatology that advances in magnetic resonance imaging (MRI) can now provide. MRI is the gold standard if an hypoxic ischemic pathology is suspected in a full term neonate. In prematures, the specific role of MRI remains to be defined, secondary to US in any case. We present a state of the art of hardware and software technical developments in MRI. The increase in magnetic field strength (3 tesla) and the emergence of new MRI sequences provide access to new information. They both have positive and negative consequences on the daily clinical data acquisition use. The semiology of brain imaging in full term newborns and prematures is more extensive and complex and thereby more difficult to interpret. The segmentation of different brain structures in the newborn, even very premature, is now available. It is now possible to dissociate the cortex and basal ganglia from the cerebral white matter, to calculate the volume of anatomical structures, which improves the morphometric quantification and the understanding of the normal and abnormal brain development. MRI is a powerful tool to analyze the neonatal brain. The relevance of the diagnostic contribution requires an adaptation of the parameters of the sequences to acquire and of the image processing methods.

  15. Diffusion MRI in the heart

    PubMed Central

    Mekkaoui, Choukri; Reese, Timothy G.; Jackowski, Marcel P.; Bhat, Himanshu

    2015-01-01

    Diffusion MRI provides unique information on the structure, organization, and integrity of the myocardium without the need for exogenous contrast agents. Diffusion MRI in the heart, however, has proven technically challenging because of the intrinsic non‐rigid deformation during the cardiac cycle, displacement of the myocardium due to respiratory motion, signal inhomogeneity within the thorax, and short transverse relaxation times. Recently developed accelerated diffusion‐weighted MR acquisition sequences combined with advanced post‐processing techniques have improved the accuracy and efficiency of diffusion MRI in the myocardium. In this review, we describe the solutions and approaches that have been developed to enable diffusion MRI of the heart in vivo, including a dual‐gated stimulated echo approach, a velocity‐ (M 1) or an acceleration‐ (M 2) compensated pulsed gradient spin echo approach, and the use of principal component analysis filtering. The structure of the myocardium and the application of these techniques in ischemic heart disease are also briefly reviewed. The advent of clinical MR systems with stronger gradients will likely facilitate the translation of cardiac diffusion MRI into clinical use. The addition of diffusion MRI to the well‐established set of cardiovascular imaging techniques should lead to new and complementary approaches for the diagnosis and evaluation of patients with heart disease. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26484848

  16. Repeat surgery for focal cortical dysplasias in children: indications and outcomes.

    PubMed

    Sacino, Matthew F; Ho, Cheng-Ying; Whitehead, Matthew T; Kao, Amy; Depositario-Cabacar, Dewi; Myseros, John S; Magge, Suresh N; Keating, Robert F; Gaillard, William D; Oluigbo, Chima O

    2017-02-01

    OBJECTIVE Focal cortical dysplasia (FCD) is a common cause of medically intractable epilepsy that often may be treated by surgery. Following resection, many patients continue to experience seizures, necessitating a decision for further surgery to achieve the desired seizure outcomes. Few studies exist on the efficacy of reoperation for intractable epilepsy due to FCD in pediatric cohorts, including the definition of prognostic factors correlated with clinical benefit from further resection. METHODS The authors retrospectively analyzed the medical records and MR images of 22 consecutive pediatric patients who underwent repeat FCD resection after unsuccessful first surgery at the Children's National Health System between March 2005 and April 2015. RESULTS Accounting for all reoperations, 13 (59%) of the 22 patients achieved complete seizure freedom and another 5 patients (23%) achieved significant improvement in seizure control. Univariate analysis demonstrated that concordance in electrocorticography (ECoG) and MRI localization (p = 0.005), and completeness of resection (p = 0.0001), were associated with seizure freedom after the first reoperation. Patients with discordant ECoG and MRI findings ultimately benefited from aggressive multilobe lobectomy or hemispherectomy. Repeat lesionectomies utilizing intraoperative MRI (iMRI; n = 9) achieved complete resection and seizure freedom in all cases. CONCLUSIONS Reoperation may be clinically beneficial in patients with intractable epilepsy due to FCD. Patients with concordant intraoperative ECoG and MRI localization may benefit from extended resection of residual dysplasia at the margins of the previous lesional cavity, and iMRI may offer benefits as a quality control mechanism to ensure that a complete resection has been accomplished. Patients with discordant findings may benefit from more aggressive resections at earlier stages to achieve better seizure control and ensure functional plasticity.

  17. Dominant short repeated sequences in bacterial genomes.

    PubMed

    Avershina, Ekaterina; Rudi, Knut

    2015-03-01

    We use a novel multidimensional searching approach to present the first exhaustive search for all possible repeated sequences in 166 genomes selected to cover the bacterial domain. We found an overrepresentation of repeated sequences in all but one of the genomes. The most prevalent repeats by far were related to interspaced short palindromic repeats (CRISPRs)—conferring bacterial adaptive immunity. We identified a deep branching clade of thermophilic Firmicutes containing the highest number of CRISPR repeats. We also identified a high prevalence of tandem repeated heptamers. In addition, we identified GC-rich repeats that could potentially be involved in recombination events. Finally, we identified repeats in a 16322 amino acid mega protein (involved in biofilm formation) and inverted repeats flanking miniature transposable elements (MITEs). In conclusion, the exhaustive search for repeated sequences identified new elements and distribution of these, which has implications for understanding both the ecology and evolution of bacteria.

  18. Three-dimensional assessment of mandibular advancement 1 year after surgery

    PubMed Central

    de Assis Ribeiro Carvalho, Felipe; Cevidanes, Lucia Helena Soares; Motta, Alexandre Trindade Simões da; de Oliveira Almeida, Marco Antonio; Phillips, Ceib

    2010-01-01

    Introduction This prospective observational study evaluated changes in the 3-dimensional position and remodeling of the mandibular rami, condyles, and chin at splint removal and 1 year after mandibular advancement surgery. Methods Presurgery, splint removal (4–6 weeks postsurgery), and 1-year postsurgery cone-beam computed tomography scans of 27 subjects were used. Superimposition on the cranial base was used to assess positional or remodeling changes in the anatomic regions of interest. Surface distance displacements were visually displayed and quantified by 3-dimensional color maps. A 1-sample t test was used to assess the average postsurgical changes of each region of interest. The level of significance was set at 0.05. Results After antero-inferior chin displacement with surgery (mean, 6.81 ± 3.2 mm at splint removal), the average 1-year post-surgery displacement was not statistically significant (P = 0.44). Postsurgical adaptations greater than 2 mm were observed in 48% of the patients: 16% with an additional anterior-inferior displacement of the chin of 2 to 4 mm, and 4% with ≥4 mm; 20% had postero-superior movement of 2 to 4 mm, and 8% had postero-superior movement of ≥4 mm. The condyles tended to move, on average, ≤2 mm supero-posteriorly with surgery, and this small positional displacement was maintained 1 year postsurgery (right condyle, P = 0.58; left, P = 0.88). The rami exhibited outward (lateral) movements with surgery, with greater displacement of the inferior part of the rami (≥2 mm in 65% of the subjects). This torque of the ramus with surgery was stable 1 year postsurgery. Conclusions Three-dimensional assessment of skeletal changes with mandibular advancement surgery shows that nearly half of the patients have >2 mm change in chin position from splint removal to the 1-year follow-up, with approximately equal chances of anterior and posterior movement. Torque of the rami usually occurs with mandibular advancement surgery. PMID:20381760

  19. Reliability of using a fixed matrix in coregistration of combined PET-MRI in a split magnet design.

    PubMed

    Sawiak, Sj; Hawkes, Rc; Ansorge, Re; Carpenter, Ta

    2013-02-21

    We consider the effects of using a fixed linear transformation to match positron emission tomography (PET) and magnetic resonance imaging (MRI) data acquired simultaneously using a split-magnet system. Estimates of the frequency offset in MRI scans were used to calculate geometric variability in MRI reconstruction as a consequence of mis-setting this parameter in addition to repeated estimation of the transformation matrix by manual measurements. None of the measured variability approached the resolution of the PET images so we concluded that a fixed matrix can be reliably used in such a system.

  20. Observations of Soft Gamma Repeaters

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2004-01-01

    Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emit&ng hundreds of predominantly soft (kT=30 kev), short (0.1-100 ms long) events. Their quiescent source x-ray light ewes exhibit puhlions rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14- 10^l5 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence were obtained in 1998 for two of these sources. I will discuss here the history of Soft Gamma Repeaters, and their spectral, timing and flux characteristics both in the persistent and their burst emission.

  1. Early Neuropsychological Tests as Correlates of Productivity 1 Year after Traumatic Brain Injury: A Preliminary Matched Case-Control Study

    ERIC Educational Resources Information Center

    Ryu, Won Hyung A.; Cullen, Nora K.; Bayley, Mark T.

    2010-01-01

    This study explored the relative strength of five neuropsychological tests in correlating with productivity 1 year after traumatic brain injury (TBI). Six moderate-to-severe TBI patients who returned to work at 1-year post-injury were matched with six controls who were unemployed after 1 year based on age, severity of injury, and Functional…

  2. A repeating fast radio burst

    NASA Astrophysics Data System (ADS)

    Spitler, L. G.; Scholz, P.; Hessels, J. W. T.; Bogdanov, S.; Brazier, A.; Camilo, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J.; Ferdman, R. D.; Freire, P. C. C.; Kaspi, V. M.; Lazarus, P.; Lynch, R.; Madsen, E. C.; McLaughlin, M. A.; Patel, C.; Ransom, S. M.; Seymour, A.; Stairs, I. H.; Stappers, B. W.; van Leeuwen, J.; Zhu, W. W.

    2016-03-01

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  3. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  4. Cognitive and affective assessment in day care versus institutionalized elderly patients: a 1-year longitudinal study

    PubMed Central

    Maseda, Ana; Balo, Aránzazu; Lorenzo–López, Laura; Lodeiro–Fernández, Leire; Rodríguez–Villamil, José Luis; Millán–Calenti, José Carlos

    2014-01-01

    Purpose Cognitive decline and depression are two common mental health problems that may create a need for long-term care among the elderly. In the last decade, the percentage of older adults who receive health care in nursing homes, day care centers, or home support services has increased in Europe. The objectives of this descriptive and nonrandomized longitudinal study were to evaluate and to compare the cognitive and affective evolution of day care versus institutionalized older patients through a 1-year period, and to assess the presence of cognitive and affective impairment as a function of the care setting. Patients and methods Ninety-four patients were assessed at baseline, and 63 (67.0%) were reassessed 1 year later. Neuropsychological assessment included measures of cognitive performance (general cognitive status, visuospatial, and language abilities) and affective status (depressive symptoms). Results Our findings indicated that the majority of the participants (day care and institutionalized patients) had mild–moderate cognitive impairment at baseline, which significantly increased in both groups after 1-year follow-up. However, the rate of change in global cognitive function did not significantly differ between groups over time. Regarding language abilities, naming function maintained among day care patients in comparison with institutionalized patients, who showed worse performance at follow-up. As regards to affective status, results revealed that institutionalized patients had a significant reduction in depressive symptoms at follow-up, when compared to day care patients. Results also highlight the high frequency of cognitive impairment and depressive symptoms regardless of the care setting. Conclusion Our findings revealed a similar global cognitive decline rate between patients receiving day care services and those residing in a nursing home at the 1-year follow-up, and slightly different trajectories in other outcomes such as naming function and

  5. Corneal Aberrations, Contrast Sensitivity, and Light Distortion in Orthokeratology Patients: 1-Year Results

    PubMed Central

    2016-01-01

    Purpose. To evaluate the corneal higher-order aberrations (HOA), contrast sensitivity function (CSF), and light distortion (LD) in patients undergoing orthokeratology (OK). Methods. Twenty healthy subjects (mean age: 21.40 ± 8 years) with mean spherical equivalent refractive error M = −2.19 ± 0.97 D were evaluated at 1 day, 1 month, and 1 year after starting OK treatment. Monocular LD, photopic monocular CSF, and corneal HOA for 6 mm pupil size were measured. Results. LD showed an increase after the first night (p < 0.05) and recovery to baseline after 1 month, remaining stable after 1 year (p > 0.05). Spherical-like, coma-like, and secondary astigmatism HOA RMS increased significantly (p ≤ 0.022) from baseline to 1-month visit, remaining unchanged over the follow-up. Contrast sensitivity for medium frequencies (3.0, 4.24, and 6.00 cpd) was significantly correlated with LD parameters at baseline (r ≤ −0.529, p < 0.001). However, after 1 year of treatment, this correlation was only statistically significant for 12 cpd spatial frequency (r ≤ −0.565, p < 0.001). Spherical-like RMS for 6 mm pupil size correlated with irregularity of the LD (r = −0.420, p < 0.05) at the 1-year visit. Conclusion. LD experienced by OK patients recovers after one month of treatment and remains stable in the long term while optical aberrations remain significantly higher than baseline. PMID:27867660

  6. Project FLAVOR: 1-Year Outcomes of a Multicultural, School-Based Smoking Prevention Curriculum for Adolescents.

    PubMed

    Unger, Jennifer B; Chou, Chih-Ping; Palmer, Paula H; Ritt-Olson, Anamara; Gallaher, Peggy; Cen, Steven; Lichtman, Kara; Azen, Stanley; Johnson, C Anderson

    2004-02-01

    To evaluate a multicultural smoking prevention curriculum, 16 schools were randomized to receive the multicultural curriculum or a standard curriculum and program effects on 1-year smoking initiation among 1430 never smokers were assessed. Hispanic boys who received the multicultural curriculum were less likely to initiate smoking than were those who received the standard curriculum; effects were insignificant among other groups. The prevention effect among Hispanic boys is encouraging, but additional research is needed to improve prevention effects among other groups.

  7. Corneal Aberrations, Contrast Sensitivity, and Light Distortion in Orthokeratology Patients: 1-Year Results.

    PubMed

    Santolaria-Sanz, Elena; Cerviño, Alejandro; González-Méijome, José M

    2016-01-01

    Purpose. To evaluate the corneal higher-order aberrations (HOA), contrast sensitivity function (CSF), and light distortion (LD) in patients undergoing orthokeratology (OK). Methods. Twenty healthy subjects (mean age: 21.40 ± 8 years) with mean spherical equivalent refractive error M = -2.19 ± 0.97 D were evaluated at 1 day, 1 month, and 1 year after starting OK treatment. Monocular LD, photopic monocular CSF, and corneal HOA for 6 mm pupil size were measured. Results. LD showed an increase after the first night (p < 0.05) and recovery to baseline after 1 month, remaining stable after 1 year (p > 0.05). Spherical-like, coma-like, and secondary astigmatism HOA RMS increased significantly (p ≤ 0.022) from baseline to 1-month visit, remaining unchanged over the follow-up. Contrast sensitivity for medium frequencies (3.0, 4.24, and 6.00 cpd) was significantly correlated with LD parameters at baseline (r ≤ -0.529, p < 0.001). However, after 1 year of treatment, this correlation was only statistically significant for 12 cpd spatial frequency (r ≤ -0.565, p < 0.001). Spherical-like RMS for 6 mm pupil size correlated with irregularity of the LD (r = -0.420, p < 0.05) at the 1-year visit. Conclusion. LD experienced by OK patients recovers after one month of treatment and remains stable in the long term while optical aberrations remain significantly higher than baseline.

  8. Fathers' Depression Related to Positive and Negative Parenting Behaviors With 1-Year-Old Children

    PubMed Central

    Davis, Matthew M.; Freed, Gary L.; Clark, Sarah J.

    2011-01-01

    OBJECTIVE: To examine the associations between depression in fathers of 1-year-old children and specific positive and negative parenting behaviors discussed by pediatric providers at well-child visits. METHODS: We performed a cross-sectional secondary analysis by using interview data from 1746 fathers of 1-year-old children in the Fragile Families and Child Wellbeing Study. Positive parenting behaviors included fathers' reports of playing games, singing songs, and reading stories to their children ≥3 days in a typical week. Negative parenting behavior included fathers' reports of spanking their 1-year-old children in the previous month. Depression was assessed by using the World Health Organization Composite International Diagnostic Interview Short Form. Weighted bivariate and multivariate analyses of parenting behaviors were performed while controlling for demographics and paternal substance abuse. RESULTS: Overall, 7% of fathers had depression. In bivariate analyses, depressed fathers were more likely than nondepressed fathers to report spanking their 1-year-old children in the previous month (41% compared with 13%; P < .01). In multivariate analyses, depressed fathers were less likely to report reading to their children ≥3 days in a typical week (adjusted odds ratio: 0.38 [95% confidence interval: 0.15–0.98]) and much more likely to report spanking (adjusted odds ratio: 3.92 [95% confidence interval: 1.23–12.5]). Seventy-seven percent of depressed fathers reported talking to their children's doctor in the previous year. CONCLUSIONS: Paternal depression is associated with parenting behaviors relevant to well-child visits. Pediatric providers should consider screening fathers for depression, discussing specific parenting behaviors (eg, reading to children and appropriate discipline), and referring for treatment if appropriate. PMID:21402627

  9. Zonisamide for Weight Reduction in Obese Adults A 1-Year Randomized Controlled Trial

    PubMed Central

    Gadde, Kishore M.; Kopping, Mariko F.; Wagner, H. Ryan; Yonish, Gretchen M.; Allison, David B.; Bray, George A.

    2013-01-01

    SUMMARY Background Obese individuals who have failed to achieve adequate weight loss with lifestyle changes have limited non-surgical therapeutic options. We evaluated the efficacy and tolerability of zonisamide, an antiepileptic drug, for enhancing weight loss in obese patients receiving diet and lifestyle guidance. Methods This was a 1-year randomized, double-blind, placebo-controlled trial conducted between January 2006 and September 2011 at Duke University Medical Center. Patients were 225 obese (mean [SD] body mass index 37.6 [4.9]) women (134 [59.6%]) and men (91 [40.4%]) without diabetes. Interventions were daily dosing with placebo (n=74), zonisamide 200 mg (n=76), orzonisamide 400 mg (n=75), in addition to diet and lifestyle counseling by a dietitian for 1 year. Primary outcome was change in body weight at 1-year. Results Of the 225 randomized patients, 218 (97%) provided 1-year follow-up assessments. Change(least-squares mean) in body weight was -4.0 kg (−3.7%; 95% CI, −5.8 kg to −2.3 kg) for placebo, −4.4 kg (−3.9%; −6.1 to −2.6, P=.79vs placebo) for zonisamide 200 mg, and −7.3 kg (−6.8%; −9.0 to −5.6, P=.009vs placebo) for zonisamide 400 mg. In the categorical analysis,23 (31%) on placebo, 26 (34%; P=.71) on zonisamide 200 mg, and 41 (55%; P=.007) onzonisamide 400 mg achieved ≥5% weight loss; for ≥10% weight loss, the corresponding numbers were 6 (8%), 17 (22%; P=.022), and 24 (32%; P=.001). Gastrointestinal, nervous system and psychiatric adverse events occurred at a higher incidence with zonisamide than with placebo. Conclusion Zonisamide 400 mg/d moderately enhanced weight loss achieved with diet and lifestyle counseling, but had a high incidence of adverse events. PMID:23147455

  10. How hot is too hot? Live-trapped gray wolf rectal temperatures and 1-year survival

    USGS Publications Warehouse

    Barber-Meyer, Shannon M.; Mech, L. David

    2014-01-01

    The ability of physically restrained and anesthetized wolves to thermoregulate is lessened and could lead to reduced survival, yet no information is available about this subject. Therefore, we analyzed rectal temperatures related to survival 1 year post-capture from 173 adult (non-pup) gray wolves (Canis lupus) captured in modified foot-hold traps for radiocollaring during June–August, 1988–2011, in the Superior National Forest of northeastern Minnesota, USA. The maximum observed rectal temperature (“maxtemp,” ° F, ° C) in each wolf during capture (x = 104.0, 40.0; SD = 2.0, 1.1; min. = 95.9, 35.5; max. = 108, 42.2) was not a significant predictor of survival to 1 year post-capture. Although no weather or morphometric variable was a significant predictor of maxtemps, wolves initially anesthetized with ketamine–xylazine rather than telazol®–xylazine averaged higher maxtemps. This information does not fully address possible effects of high body temperatures related to live-capture and handling of wolves, but it does provide a useful waypoint for future assessments of this relationship and a reassurance to wildlife practitioners that the maxtemps observed in our study did not appear to affect 1-year survival.

  11. Predictors of Relapse after Inpatient Opioid Detoxification during 1-Year Follow-Up

    PubMed Central

    2016-01-01

    Introduction. Relapse rate after opioid detoxification is very high. We studied the possibility that predetoxification patient characteristics might predict relapse at follow-up and thus conducted this 1-year follow-up study to assess the predictors of relapse after inpatient opioid detoxification. Materials and Methods. We conducted this study in our tertiary care institute in India over two-year time period (1 Jan 2014 to 31 Dec 2015). Out of 581 patients admitted, 466 patients were considered for study. Results and Discussion. No significant difference was found between relapsed and nonrelapsed patients regarding sociodemographic profile; however substance abuse pattern and forensic history showed significant differences. Relapsed patients abused greater amount and used injections more commonly, as compared to nonrelapsed group. Longer duration of abuse was also a significant risk factor. Patients with past attempt of opioid detoxification and family history (parental or first degree) of alcohol abuse had decreased possibility of maintaining remission during 1-year follow-up. Relapsed patients were found to abuse their spouse or parents. Conclusion. Our study compared profiles of relapsed and nonrelapsed patients after inpatient detoxification and concluded predictors of relapse during 1-year follow-up period. Early identification of predictors of relapse and hence high risk patients might be helpful in designing more effective and focused treatment plan. PMID:27722007

  12. Longitudinal changes in prospective memory and their clinical correlates at 1-year follow-up in first-episode schizophrenia

    PubMed Central

    Ungvari, Gabor S.; Ng, Chee H.; Zhou, Yan; Zhang, Liang; Zhou, Jingjing; Shum, David H. K.; Man, David; Liu, Deng-Tang; Li, Jun; Xiang, Yu-Tao

    2017-01-01

    This study aimed to investigate prospective memory (PM) and the association with clinical factors at 1-year follow-up in first-episode schizophrenia (FES). Thirty-two FES patients recruited from a university-affiliated psychiatric hospital in Beijing and 17 healthy community controls (HCs) were included. Time- and event-based PM (TBPM and EBPM) performances were measured with the Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) at baseline and at one-year follow-up. A number of other neurocognitive tests were also administered. Remission was determined at the endpoint according to the PANSS score ≤ 3 for selected items. Repeated measures analysis of variance revealed a significant interaction between time (baseline vs. endpoint) and group (FES vs. HCs) for EBPM (F(1, 44) = 8.8, p = 0.005) and for all neurocognitive components. Paired samples t-tests showed significant improvement in EBPM in FES (13.1±3.7 vs. 10.3±4.8; t = 3.065, p = 0.004), compared to HCs (15.7±3.6 vs. 16.5±2.3; t = -1.248, p = 0.230). A remission rate of 59.4% was found in the FES group. Analysis of covariance revealed that remitters performed significantly better on EBPM (14.9±2.6 vs. 10.4±3.6; F(1, 25) = 12.2, p = 0.002) than non-remitters at study endpoint. The association between EBPM and 12-month clinical improvement in FES suggests that EBPM may be a potential neurocognitive marker for the effectiveness of standard pharmacotherapy. Furthermore, the findings also imply that PM may not be strictly a trait-related endophenotype as indicated in previous studies. PMID:28245266

  13. Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation.

    PubMed

    Bond, Aaron E; Jane, John A; Liu, Kenneth C; Oldfield, Edward H

    2015-05-01

    OBJECT The authors completed a prospective, institutional review board-approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed. METHODS Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. All patients underwent complete T1, T2, and cine MRI studies in the supine position preoperatively as a baseline. After the patient was placed prone with the neck flexed in position for surgery, iMRI was performed. The patient then underwent a bone decompression of the foramen magnum and arch of C-1, and the MRI was repeated. If obstruction was still present, then in a stepwise fashion the patient underwent dural splitting, duraplasty, and coagulation of the tonsils, with an iMRI study performed after each step guiding the decision to proceed further. RESULTS Eighteen patients underwent PFD for Chiari I malformations between November 2011 and February 2013; 15 prone preincision iMRIs were performed. Fourteen of these patients (93%) demonstrated significant improvement of CSF flow through the foramen magnum dorsal to the tonsils with positioning only. This improvement was so notable that changes in CSF flow as a result of the bone decompression were difficult to discern. CONCLUSIONS The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is

  14. Prediction of Cognitive Decline in Healthy Older Adults using fMRI

    PubMed Central

    Woodard, John L.; Seidenberg, Michael; Nielson, Kristy A.; Smith, J. Carson; Antuono, Piero; Durgerian, Sally; Guidotti, Leslie; Zhang, Qi; Butts, Alissa; Hantke, Nathan; Lancaster, Melissa; Rao, Stephen M.

    2010-01-01

    Few studies have examined the extent to which structural and functional MRI, alone and in combination with genetic biomarkers, can predict future cognitive decline in asymptomatic elders. This prospective study evaluated individual and combined contributions of demographic information, genetic risk, hippocampal volume, and fMRI activation for predicting cognitive decline after an 18-month retest interval. Standardized neuropsychological testing, an fMRI scans semantic memory task (famous name discrimination), and structural MRI (sMRI) were performed on 78 healthy elders (73% female; mean age = 73 years, range = 65 to 88 years). Positive family history of dementia and presence of one or both apolipoprotein E (APOE) ε4 alleles occurred in 51.3% and 33.3% of the sample, respectively. Hippocampal volumes were traced from sMRI scans. At follow-up, all participants underwent a repeat neuropsychological examination. At 18 months, 27 participants (34.6%) declined by at least 1 SD on one of three neuropsychological measures. Using logistic regression, demographic variables (age, years of education, gender) and family history of dementia did not predict future cognitive decline. Greater fMRI activity, absence of an APOE ε4 allele, and larger hippocampal volume were associated with reduced likelihood of cognitive decline. The most effective combination of predictors involved fMRI brain activity and APOE ε4 status. Brain activity measured from task-activated fMRI, in combination with APOE ε4 status, was successful in identifying cognitively intact individuals at greatest risk for developing cognitive decline over a relatively brief time period. These results have implications for enriching prevention clinical trials designed to slow AD progression. PMID:20634590

  15. Estimating Motion From MRI Data

    PubMed Central

    OZTURK, CENGIZHAN; DERBYSHIRE, J. ANDREW; MCVEIGH, ELLIOT R.

    2007-01-01

    Invited Paper Magnetic resonance imaging (MRI) is an ideal imaging modality to measure blood flow and tissue motion. It provides excellent contrast between soft tissues, and images can be acquired at positions and orientations freely defined by the user. From a temporal sequence of MR images, boundaries and edges of tissues can be tracked by image processing techniques. Additionally, MRI permits the source of the image signal to be manipulated. For example, temporary magnetic tags displaying a pattern of variable brightness may be placed in the object using MR saturation techniques, giving the user a known pattern to detect for motion tracking. The MRI signal is a modulated complex quantity, being derived from a rotating magnetic field in the form of an induced current. Well-defined patterns can also be introduced into the phase of the magnetization, and could be thought of as generalized tags. If the phase of each pixel is preserved during image reconstruction, relative phase shifts can be used to directly encode displacement, velocity and acceleration. New methods for modeling motion fields from MRI have now found application in cardiovascular and other soft tissue imaging. In this review, we shall describe the methods used for encoding, imaging, and modeling motion fields with MRI. PMID:18958181

  16. MRI Abnormalities Are Common In Little League Player’s Elbows

    PubMed Central

    Pennock, Andrew T.; Roocroft, Joanna Helena; Bastrom, Tracey P.; Kruk, Peter

    2016-01-01

    Objectives: Youth baseball is extremely popular, but it has been associated with elbow pain and pathology. The purpose of this study was to examine pre- and post-season Magnetic Resonance Imaging (MRI) changes in Little League baseball players and correlate these findings with the players’ throwing history and physical exams. Methods: A prospective study of Little League players age 10 -13 years was performed. Players were recruited prior to the start of the season and underwent bilateral elbow MRI. All players underwent a physical exam and responded to a questionnaire addressing their playing history and arm pain. At the end of the season, the players underwent repeat physical exam and MRI of their throwing arm. MRIs were read by two blinded radiologists. During the season, player statistics including innings played and pitch counts were recorded. Physical exam findings and players statistics were compared between subjects with and without MRI changes utilizing chi-square and ANOVA techniques. Results: Twenty-six players were enrolled. On pre-season MRI, nine players (35%) had 12 positive MRI findings; edema of the medial epicondyle (ME) apophysis (7), fragmentation of ME (2), and edema of the sublime tubercle (3). The two factors associated with a positive MRI were year round play (47% vs 11%, p<0.01) and working with a private coach (71% vs 21%, p=0.02). A history of pain was also associated with year round play and a private coach (p<0.05). Loss of internal rotation was associated with an abnormal MRI (p = 0.04). Post-season, 25 players returned for follow-up. Ten players (40%) had an abnormal MRI of which 8 (32%) had new/worsening findings. There was a significant difference in distal humeral physeal width measured pre- to post-season (1.54 mm vs 2.31 mm p<0.001). There was a significant decrease in internal rotation measured pre- to post-season of the shoulder in all patients regardless of MRI findings (62° vs 43°, p=0.001). Pitch counts, player position

  17. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  18. Efficacy of risedronate in men with primary and secondary osteoporosis: results of a 1-year study.

    PubMed

    Ringe, J D; Faber, H; Farahmand, P; Dorst, A

    2006-03-01

    Osteoporosis is prevalent in men with an estimated one in eight men older than 50 years suffering from osteoporotic fracture, and a higher mortality rate after fracture among men compared with women. There are few approved therapies for osteoporosis in men. This observational study assesses the efficacy and safety of risedronate in the treatment of men with primary and secondary osteoporosis. A single-center, open label, randomized, prospective 1-year study was conducted in men with primary or secondary osteoporosis. Patients were randomized to risedronate (risedronate 5 mg/day plus calcium 1,000 mg/day and vitamin D 800 IU/day) or control groups (alfacalcidol 1 mug/day plus calcium 500 mg/day or vitamin D 1,000 IU/day plus calcium 800 mg/day). Bone mineral density (BMD) measurements, X-rays of the spine, a medical history and physical exam, and patient self-assessments of back pain were performed at baseline and 12 months. Blinded semi-quantitative fracture assessment was conducted by a radiologist. A total of 316 men with osteoporosis were enrolled in the trial (risedronate, n=158; control, n=158). At 1 year lumbar spine BMD increased by 4.7% in the risedronate group versus an increase of 1.0% in the control group (P<0.001). Significant increases in BMD at the total hip and femoral neck were also observed with risedronate compared with the control group. The incidence of new vertebral fracture in the risedronate group was reduced by 60% versus the control group (P=0.028). Daily treatment with risedronate for 12 months significantly increased BMD at the lumbar spine, femoral neck and total hip and significantly reduced the incidence of new vertebral fractures. This is the first prospective, randomized, controlled trial to demonstrate a significant reduction in vertebral fractures in 1 year in men with primary or secondary osteoporosis.

  19. Accelerated Gastric Emptying but No Carbohydrate Malabsorption 1 Year After Gastric Bypass Surgery (GBP)

    PubMed Central

    Wang, Gary; Agenor, Keesandra; Pizot, Justine; Kotler, Donald P.; Harel, Yaniv; Van Der Schueren, Bart J.; Quercia, Iliana; McGinty, James

    2013-01-01

    Background Following gastric bypass surgery (GBP), there is a post-prandial rise of incretin and satiety gut peptides. The mechanisms of enhanced incretin release in response to nutrients after GBP is not elucidated and may be in relation to altered nutrient transit time and/or malabsorption. Methods Seven morbidly obese subjects (BMI=44.5±2.8 kg/m2) were studied before and 1 year after GBP with a d-xylose test. After ingestion of 25 g of d-xylose in 200 mL of non-carbonated water, blood samples were collected at frequent time intervals to determine gastric emptying (time to appearance of d-xylose) and carbohydrate absorption using standard criteria. Results One year after GBP, subjects lost 45.0±9.7 kg and had a BMI of 27.1±4.7 kg/m2. Gastric emptying was more rapid after GBP. The mean time to appearance of d-xylose in serum decreased from 18.6±6.9 min prior to GBP to 7.9±2.7 min after GBP (p=0.006). There was no significant difference in absorption before (serum d-xylose concentrations=35.6±12.6 mg/dL at 60 min and 33.9±9.1 mg/dL at 180 min) or 1 year after GBP (serum d-xylose=31.5± 18.1 mg/dL at 60 min and 27.2±11.9 mg/dL at 180 min). Conclusions These data confirm the acceleration of gastric emptying for liquid and the absence of carbohydrate malabsorption 1 year after GBP. Rapid gastric emptying may play a role in incretin response after GBP and the resulting improved glucose homeostasis. PMID:22527599

  20. Environmental exposures and respiratory morbidity among very low birth weight infants at 1 year of life

    PubMed Central

    Halterman, J S; Lynch, K A; Conn, K M; Hernandez, T E; Perry, T T; Stevens, T P

    2016-01-01

    Introduction Preterm infants have a substantially increased risk of developing respiratory illnesses. The goal of this study was to consider the impact of modifiable postnatal exposures on respiratory morbidity among a cohort of very low birth weight (VLBW) infants. Objectives (1) Assess the rates of respiratory morbidity and exposure to indoor respiratory triggers in a population of VLBW infants at 1 year; (2) determine the association between exposures and respiratory morbidity. Methods We enrolled 124 VLBW infants into a prospective cohort study. Parents were called at 1 year to assess respiratory outcomes and environmental exposures. We used bivariate and multivariate analyses to assess the relationship between environmental exposures and acute care for respiratory illnesses. Results At 1 year, 9% of infants had physician-diagnosed asthma, 47% required ≥1 acute visit and 11% required hospitalisation for respiratory illness. The majority of infants (82%) were exposed to at least one indoor respiratory trigger. Infants living with a smoker (61% vs 40%) and infants exposed to pests (62% vs 39%) were more likely than unexposed infants to require acute care for respiratory problems. In a multivariate regression controlling for demographics, birth weight, bronchopulmonary dysplasia, and family history of asthma or allergies, both living with a smoker (OR 2.62; CI 1.09 to 6.29) and exposure to pests (OR 4.41; CI 1.22 to 15.94) were independently associated with the need for acute care for respiratory illnesses. Conclusions In this sample, respiratory morbidity and exposure to triggers were common. VLBW infants may benefit from interventions that decrease exposure to respiratory triggers. PMID:18703545

  1. For Diabetes Shared Savings Programs, 1 Year of Data Is Not Enough.

    PubMed

    VanArsdale, Lynne; Curran-Everett, Douglas; Haugen, Heather; Smith, Nancy; Atherly, Adam

    2017-04-01

    Fee-for-service payment models are moving toward pay-for-performance designs, many of which rely on shared savings for financial sustainability. Shared savings programs divide the cost savings between health care purchaser and provider based on provider performance. Often, these programs measure provider performance as the delivery of agreed-upon clinical practice guidelines that usually are represented as evidence-based medicine (EBM). Multiyear studies show a negative relationship between total cost and EBM, indicating that long-term shared savings can be substantial. This study explores expectations for the rewards in the first year of a shared savings program. It also indicates the effectiveness of using 1 year of claims to assess cost savings from evidence-based care, especially in a patient population with high turnover. This study analyzed 1956 adults with diabetes insured through Medicaid. Results of linear regression showed that the relationship between total cost of care and each element of evidence-based medical care during a 1-year period was positive (higher cost) or insignificant. The results indicate that diabetes EBM programs cannot expect to see significant cost savings if the evaluation lasts only 1 year or less. The study concludes that improvements in EBM incentive programs could come from investigating the length of time needed to realize cost savings from each element of diabetes EBM. Investigating other factors that could affect the expected amount of cost savings also would benefit these programs, especially factors derived from sources external to insurance program information such as the medical record and care management data.

  2. A comparison of emission calculations using different modeled indicators with 1-year online measurements.

    PubMed

    Lengers, Bernd; Schiefler, Inga; Büscher, Wolfgang

    2013-12-01

    The overall measurement of farm level greenhouse gas (GHG) emissions in dairy production is not feasible, from either an engineering or administrative point of view. Instead, computational model systems are used to generate emission inventories, demanding a validation by measurement data. This paper tests the GHG calculation of the dairy farm-level optimization model DAIRYDYN, including methane (CH₄) from enteric fermentation and managed manure. The model involves four emission calculation procedures (indicators), differing in the aggregation level of relevant input variables. The corresponding emission factors used by the indicators range from default per cow (activity level) emissions up to emission factors based on feed intake, manure amount, and milk production intensity. For validation of the CH₄ accounting of the model, 1-year CH₄ measurements of an experimental free-stall dairy farm in Germany are compared to model simulation results. An advantage of this interdisciplinary study is given by the correspondence of the model parameterization and simulation horizon with the experimental farm's characteristics and measurement period. The results clarify that modeled emission inventories (2,898, 4,637, 4,247, and 3,600 kg CO₂-eq. cow(-1) year(-1)) lead to more or less good approximations of online measurements (average 3,845 kg CO₂-eq. cow(-1) year(-1) (±275 owing to manure management)) depending on the indicator utilized. The more farm-specific characteristics are used by the GHG indicator; the lower is the bias of the modeled emissions. Results underline that an accurate emission calculation procedure should capture differences in energy intake, owing to milk production intensity as well as manure storage time. Despite the differences between indicator estimates, the deviation of modeled GHGs using detailed indicators in DAIRYDYN from on-farm measurements is relatively low (between -6.4% and 10.5%), compared with findings from the literature.

  3. Predictors of fatigue over 1 year among people with rheumatoid arthritis.

    PubMed

    Treharne, G J; Lyons, A C; Hale, E D; Goodchild, C E; Booth, D A; Kitas, G D

    2008-08-01

    Fatigue is a systemic feeling of exhaustion that is a common symptom of many chronic illnesses, including the autoimmune inflammatory disease rheumatoid arthritis (RA). We examined predictors of levels of fatigue among people with RA using Leventhal's Common-Sense Model (CSM), which states that cognitive representations of an illness spur (or halt) people's efforts to cope and thereby influence outcomes of the illness. Our use of the CSM was designed in the light of evidence in the literature specific to fatigue in RA. Current fatigue was reported on a 100 mm visual analogue scale (with anchors "No fatigue" and "Unbearable fatigue") by 114 people (73.7% women) with RA at baseline and 1 year later. Baseline employment status, pain, impact of disability, sleep disruption frequency, depressed mood, perceptions of consequences, arthritis self-efficacy and attempts to cope by praying/hoping were also self-reported. Duration of RA and a haematological measure of systemic inflammation (erythrocyte sedimentation rate; ESR) were obtained from hospital records. Unexpectedly, RA duration did not predict fatigue after 1 year, although lower baseline inflammation did (controlling for baseline fatigue and other disease impact variables). This may be due to sampling flares of RA at baseline. Baseline perceptions that RA has severe consequences and is uncontrollable also predicted greater fatigue after 1 year but this relationship was not mediated by praying/hoping. Targeted psychological care to modify perceptions of severe consequences may therefore improve later fatigue for people with RA even when the condition is longstanding, but the mechanisms of any benefit require further investigation.

  4. Necessity and Opportunity: the 1-Year Master's ABA Program at Auburn University.

    PubMed

    Johnston, James M

    2016-05-01

    The Auburn University Master of Science program in Applied Behavior Analysis was designed to accommodate not only the requirements of the Behavior Analyst Certification Board for approved course sequences and practicum training, but unavoidable limitations in faculty and other resources. These limitations were incompatible with the more traditional 2-year curriculum model, so a 1-year program was designed that met the necessary conditions. This article describes the resulting academic and practicum curriculum, the key funding mechanisms that allowed the program to develop, and the opportunities and benefits that this model afforded.

  5. Fetal MRI: A pictorial essay

    PubMed Central

    Rathee, Sapna; Joshi, Priscilla; Kelkar, Abhimanyu; Seth, Nagesh

    2016-01-01

    Ultrasonography (USG) is the primary method for antenatal fetal evaluation. However, fetal magnetic resonance imaging (MRI) has now become a valuable adjunct to USG in confirming/excluding suspected abnormalities and in the detection of additional abnormalities, thus changing the outcome of pregnancy and optimizing perinatal management. With the development of ultrafast sequences, fetal MRI has made remarkable progress in recent times. In this pictorial essay, we illustrate a spectrum of structural abnormalities affecting the central nervous system, thorax, genitourinary and gastrointestinal tract, as well as miscellaneous anomalies. Anomalies in twin gestations and placental abnormalities have also been included. PMID:27081224

  6. [MRI of the pineal gland].

    PubMed

    Langevad, Line; Madsen, Camilla Gøbel; Siebner, Hartwig; Garde, Ellen

    2014-11-10

    The pineal gland (CP) is located centrally in the brain and produces melatonin. Cysts and concrements are frequent findings on MRI but their significance is still unclear. The visualization of CP is difficult due to its location and surrounding structures and so far, no standardized method exists. New studies suggest a correlation between CP-morphology and melatonin secretion as well as a connection between melatonin, disturbed circadian rhythm, and the development of cancer and cardiovascular diseases, underlining the need for a standardized approach to CP on MRI.

  7. MRI EVALUATION OF KNEE CARTILAGE

    PubMed Central

    Rodrigues, Marcelo Bordalo; Camanho, Gilberto Luís

    2015-01-01

    Through the ability of magnetic resonance imaging (MRI) to characterize soft tissue noninvasively, it has become an excellent method for evaluating cartilage. The development of new and faster methods allowed increased resolution and contrast in evaluating chondral structure, with greater diagnostic accuracy. In addition, physiological techniques for cartilage assessment that can detect early changes before the appearance of cracks and erosion have been developed. In this updating article, the various techniques for chondral assessment using knee MRI will be discussed and demonstrated. PMID:27022562

  8. Recording event-related activity under hostile magnetic resonance environment: Is multimodal EEG/ERP-MRI recording possible?

    PubMed

    Karakaş, H M; Karakaş, S; Ozkan Ceylan, A; Tali, E T

    2009-08-01

    Event-related potentials (ERPs) have high temporal resolution, but insufficient spatial resolution; the converse is true for the functional imaging techniques. The purpose of the study was to test the utility of a multimodal EEG/ERP-MRI technique which combines electroencephalography (EEG) and magnetic resonance imaging (MRI) for a simultaneously high temporal and spatial resolution. The sample consisted of 32 healthy young adults of both sexes. Auditory stimuli were delivered according to the active and passive oddball paradigms in the MRI environment (MRI-e) and in the standard conditions of the electrophysiology laboratory environment (Lab-e). Tasks were presented in a fixed order. Participants were exposed to the recording environments in a counterbalanced order. EEG data were preprocessed for MRI-related artifacts. Source localization was made using a current density reconstruction technique. The ERP waveforms for the MRI-e were morphologically similar to those for the Lab-e. The effect of the recording environment, experimental paradigm and electrode location were analyzed using a 2x2x3 analysis of variance for repeated measures. The ERP components in the two environments showed parametric variations and characteristic topographical distributions. The calculated sources were in line with the related literature. The findings indicated effortful cognitive processing in MRI-e. The study provided preliminary data on the feasibility of the multimodal EEG/ERP-MRI technique. It also indicated lines of research that are to be pursued for a decisive testing of this technique and its implementation to clinical practice.

  9. Crowding by a repeating pattern

    PubMed Central

    Rosen, Sarah; Pelli, Denis G.

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target–flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker. PMID:26024457

  10. Crowding by a repeating pattern.

    PubMed

    Rosen, Sarah; Pelli, Denis G

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target-flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker.

  11. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    MedlinePlus

    ... to 2-Year-Old Magnetic Resonance Imaging (MRI): Brain KidsHealth > For Parents > Magnetic Resonance Imaging (MRI): Brain ... child may be given headphones to listen to music or earplugs to block the noise, and will ...

  12. Evolution of Protein Domain Repeats in Metazoa

    PubMed Central

    Schüler, Andreas; Bornberg-Bauer, Erich

    2016-01-01

    Repeats are ubiquitous elements of proteins and they play important roles for cellular function and during evolution. Repeats are, however, also notoriously difficult to capture computationally and large scale studies so far had difficulties in linking genetic causes, structural properties and evolutionary trajectories of protein repeats. Here we apply recently developed methods for repeat detection and analysis to a large dataset comprising over hundred metazoan genomes. We find that repeats in larger protein families experience generally very few insertions or deletions (indels) of repeat units but there is also a significant fraction of noteworthy volatile outliers with very high indel rates. Analysis of structural data indicates that repeats with an open structure and independently folding units are more volatile and more likely to be intrinsically disordered. Such disordered repeats are also significantly enriched in sites with a high functional potential such as linear motifs. Furthermore, the most volatile repeats have a high sequence similarity between their units. Since many volatile repeats also show signs of recombination, we conclude they are often shaped by concerted evolution. Intriguingly, many of these conserved yet volatile repeats are involved in host-pathogen interactions where they might foster fast but subtle adaptation in biological arms races. Key Words: protein evolution, domain rearrangements, protein repeats, concerted evolution. PMID:27671125

  13. Repeated Reading. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2014

    2014-01-01

    "Repeated reading" is an academic practice that aims to increase oral reading fluency. "Repeated reading" can be used with students who have developed initial word reading skills but demonstrate inadequate reading fluency for their grade level. During "repeated reading," a student sits in a quiet location with a…

  14. Induction of Maturogenesis by Partial Pulpotomy: 1 Year Follow-Up

    PubMed Central

    Bacaksiz, A.; Alaçam, A.

    2013-01-01

    In cariously exposed immature permanent teeth, the treatment choice is controversial in pediatric dentistry. Radical root canal treatment usually appears to be the solution for these teeth. Even partial pulpotomy is a vital treatment for traumatically exposed immature permanent teeth; extending the borders of indication towards cariously exposed immature permanent teeth with reversible pulpitis may abolish the necessity of pulpectomy. This article describes the partial pulpotomy of a cariously affected immature permanent teeth and the follow-up for 1 year. A healthy 11-year-old male patient was referred to Gazi University Faculty of Dentistry Department of Pediatric Dentistry. The patient had reversible pulpitis symptoms on teeth numbered 45. At radiographic examination, immature apex and deep caries lesion were observed and partial pulpotomy was performed by using calcium hydroxide to maintain vitality of the pulp and allow continued development of root dentin expecting the root will attain full maturity. Clinical and radiographic follow-up demonstrated a vital pulp besides not only closure of the apex (apexogenesis), but also physiologic root development (maturogenesis) after 1 year. Partial pulpotomy is an optional treatment for cariously exposed immature permanent teeth for preserving vitality and physiological root development. PMID:24324899

  15. Parental spanking of 1-year-old children and subsequent child protective services involvement✩

    PubMed Central

    Lee, Shawna J.; Grogan-Kaylor, Andrew; Berger, Lawrence M.

    2015-01-01

    The majority of U.S. parents spank their children, often beginning when their children are very young. We examined families (N=2,788) who participated in a longitudinal community-based study of new births in urban areas. Prospective analyses examined whether spanking by the child's mother, father, or mother's current partner when the child was 1-year-old was associated with household CPS involvement between age 1 and age 5. Results indicated that 30% of 1-year-olds were spanked at least once in the past month. Spanking at age 1 was associated with increased odds of subsequent CPS involvement (adjusted odds ratio=1.36, 95% CI [1.08, 1.71], p<.01). When compared to non-spanked children, there was a 33% greater probability of subsequent CPS involvement for children who were spanked at age 1. Given the undesirable consequences of spanking children and a lack of empirical evidence to suggest positive effects of physical punishment, professionals who work with families should counsel parents not to spank infants and toddlers. For optimal benefits, efforts to educate parents regarding alternative forms of discipline should begin during the child's first year of life. PMID:24602690

  16. Phase Fluctuations at Goldstone Derived from 1-Year Site Testing Interferometer Data

    NASA Technical Reports Server (NTRS)

    Nessel, James A.; Acosta, Roberto J.; Morabito, David D.

    2009-01-01

    A two-element site test interferometer has been deployed at the NASA Deep Space Network (DSN) tracking complex in Goldstone, California, since May 2007. The interferometer system consists of two offset-fed 1.2 m parabolic reflectors which monitor atmospheric-induced amplitude and phase fluctuations on an unmodulated beacon signal (20.199 GHz) broadcast from a geostationary satellite (Anik F2). The geometry of the satellite and the ground-based infrastructure imposes a 48.5 elevation angle with a separation distance of 256 m along an east-west baseline. The interferometer has been recording phase fluctuation data, to date, for 1 yr with an overall system availability of 95 percent. In this paper, we provide the cumulative distribution functions (CDFs) for 1 year of recorded data, including phase rms, spatial structure function exponent, and surface meteorological measurements: surface wind speed, relative humidity, temperature, barometric pressure, and rain rate. Correlation between surface measurements, phase rms, and amplitude rms at different time scales are discussed. For 1 year, phase fluctuations at the DSN site in Goldstone, are better than 23 for 90 percent of the time (at 48.5 elevation). This data will be used to determine the suitability of the Goldstone site as a location for the Next Generation Deep Space Network.

  17. Induction of maturogenesis by partial pulpotomy: 1 year follow-up.

    PubMed

    Bacaksiz, A; Alaçam, A

    2013-01-01

    In cariously exposed immature permanent teeth, the treatment choice is controversial in pediatric dentistry. Radical root canal treatment usually appears to be the solution for these teeth. Even partial pulpotomy is a vital treatment for traumatically exposed immature permanent teeth; extending the borders of indication towards cariously exposed immature permanent teeth with reversible pulpitis may abolish the necessity of pulpectomy. This article describes the partial pulpotomy of a cariously affected immature permanent teeth and the follow-up for 1 year. A healthy 11-year-old male patient was referred to Gazi University Faculty of Dentistry Department of Pediatric Dentistry. The patient had reversible pulpitis symptoms on teeth numbered 45. At radiographic examination, immature apex and deep caries lesion were observed and partial pulpotomy was performed by using calcium hydroxide to maintain vitality of the pulp and allow continued development of root dentin expecting the root will attain full maturity. Clinical and radiographic follow-up demonstrated a vital pulp besides not only closure of the apex (apexogenesis), but also physiologic root development (maturogenesis) after 1 year. Partial pulpotomy is an optional treatment for cariously exposed immature permanent teeth for preserving vitality and physiological root development.

  18. Parental spanking of 1-year-old children and subsequent child protective services involvement.

    PubMed

    Lee, Shawna J; Grogan-Kaylor, Andrew; Berger, Lawrence M

    2014-05-01

    The majority of U.S. parents spank their children, often beginning when their children are very young. We examined families (N=2,788) who participated in a longitudinal community-based study of new births in urban areas. Prospective analyses examined whether spanking by the child's mother, father, or mother's current partner when the child was 1-year-old was associated with household CPS involvement between age 1 and age 5. Results indicated that 30% of 1-year-olds were spanked at least once in the past month. Spanking at age 1 was associated with increased odds of subsequent CPS involvement (adjusted odds ratio=1.36, 95% CI [1.08, 1.71], p<.01). When compared to non-spanked children, there was a 33% greater probability of subsequent CPS involvement for children who were spanked at age 1. Given the undesirable consequences of spanking children and a lack of empirical evidence to suggest positive effects of physical punishment, professionals who work with families should counsel parents not to spank infants and toddlers. For optimal benefits, efforts to educate parents regarding alternative forms of discipline should begin during the child's first year of life.

  19. Prediction of depression and anxiety 1 year after moderate-severe traumatic brain injury.

    PubMed

    Demakis, George J; Hammond, Flora M; Knotts, Allison

    2010-07-01

    This study examined three scales of the Personality Assessment Inventory (PAI; Anxiety, Anxiety-Related Disorders, and Depression) in 88 participants 1 year after they suffered a moderate-severe traumatic brain injury (TBI). Participants were all enrolled in the federally funded Traumatic Brain Injury Model System project at Carolinas Rehabilitation. The following variables were assessed at the time of injury: age, sex, employment and marital status, and length of loss of consciousness. Disability status, using the Disability Rating Scale (DRS), was assessed at the time of discharge from the rehabilitation hospital. A series of three linear regression analyses found that these variables significantly predicted scores on the Anxiety and Anxiety-Related Disorders scales, which accounted for 14% and 17.7% of the variance, respectively. The variables did not significantly predict scores on the Depression scale. Within each regression analysis, DRS was consistently and negatively related to each PAI scale, such that greater disability was associated with better psychological functioning. Such seemingly paradoxical findings are discussed in terms of anosognosia or poor awareness of psychological functioning among those with greater disability 1 year after TBI.

  20. Dialectical Behavior Therapy for Adolescents With Bipolar Disorder: A 1-Year Open Trial

    PubMed Central

    GOLDSTEIN, TINA R.; AXELSON, DAVID A.; BIRMAHER, BORIS; BRENT, DAVID A.

    2010-01-01

    Objective To describe an adapted version of dialectical behavior therapy for adolescents with bipolar disorder. Method The dialectical behavior therapy intervention is delivered over 1 year and consists of two modalities: family skills training (conducted with individual family units) and individual therapy. The acute treatment period (6 months) includes 24 weekly sessions; sessions alternate between the two treatment modalities. Continuation treatment consists of 12 additional sessions tapering in frequency through 1 year. We conducted an open pilot trial of the treatment, designed as an adjunct to pharmacological management, to establish feasibility and acceptability of the treatment for this population. Participants included 10 patients (mean age 15.8 ± 1.5 years, range 14–18) receiving treatment in an outpatient pediatric bipolar specialty clinic. Symptom severity and functioning were assessed quarterly by an independent evaluator. Consumer satisfaction was also assessed posttreatment. Results Feasibility and acceptability of the intervention were high, with 9 of 10 patients completing treatment, 90% of scheduled sessions attended, and high treatment satisfaction ratings. Patients exhibited significant improvement from pre- to posttreatment in suicidality, nonsuicidal self-injurious behavior, emotional dysregulation, and depressive symptoms. Conclusions Dialectical behavior therapy may offer promise as an approach to the psychosocial treatment of adolescent bipolar disorder. PMID:17581446

  1. Steroid hormone levels in pregnancy and 1 year postpartum using isotope dilution tandem mass spectrometry

    PubMed Central

    Soldin, Offie P.; Guo, Tiedong; Weiderpass, Elisabete; Tractenberg, Rochelle E.; Hilakivi-Clarke, Leena; Soldin, Steven J.

    2013-01-01

    Objective To establish normal, trimester-specific reference intervals for serum 17β-estradiol, progesterone (P), 17α-hydroxyprogesterone, cortisol, 11-deoxycortisol, androstenedione, DHEA, and DHEAS, measured simultaneously using isotope dilution tandem mass spectrometry. Design Sequential cohort study. Patient(s) Healthy women undergoing a normal pregnancy (age, 25–38 years; mean, 30 years) attending a prenatal well clinic at gestation weeks 12, 22, and 32 and approximately 1 year postpartum. Main Outcome Measure(s) Trimester-specific reference intervals of endogenous steroid hormones analyzed using an isotope dilution tandem mass spectrometer equipped with an atmospheric pressure photoionization source with deuterium-labeled internal standards. Result(s) Serum estradiol, P, 17α-hydroxyprogesterone, and 11-deoxycortisol increased throughout pregnancy; cortisol increased up to the second trimester and then remained steady, while androstenedione increased by 80 percent by gestation week 12, then remained constant. Serum DHEA-S decreased by 50% by the third trimester. Conclusion(s) Trimester-specific reference intervals are reported for eight serum steroids. The ratios of individual serum hormone concentrations during pregnancy relative to their 1-year postpartum concentrations illustrate the expected normal trends of changes in hormone concentrations during pregnancy. PMID:16169406

  2. Does antibiotic elution from PMMA beads deteriorate after 1-year shelf storage?

    PubMed

    Balsamo, Luke H; Whiddon, David R; Simpson, R Bruce

    2007-09-01

    Antibiotic-impregnated polymethylmethacrylate beads are widely used as an adjunct in the treatment of orthopaedic infections. Because there is no commercially available bead in the United States, surgeons must manufacture bead sets at the time of implantation. This can be time consuming and wasteful. We hypothesized antibiotic-impregnated beads would maintain consistent elution for up to 1 year after manufacturing and storage. Tobramycin-impregnated antibiotic beads were manufactured using a bead mold. The antibiotic was either hand-mixed into the polymethylmethacrylate powder (1.2 g/40 g) or came premixed from the factory (1 g/40 g). Packages of beads were gas-sterilized and stored at room temperature. Beads were tested at 0, 1, 2, 3, 6, and 12 months. Antibiotic levels in the eluent from each day of the month were measured. We were unable to detect any difference in the amount of antibiotic elution between beads tested immediately after manufacture and beads manufactured and stored for 6 or 12 months. Beads with hand-mixed antibiotics eluted higher levels of antibiotics than the beads prepared with factory-mixed antibiotics. We conclude antibiotic beads can be made, sterilized, and used after 1 year of storage with no deleterious effect on antibiotic elution characteristics.

  3. Impact of APOE4-CSF Aβ interaction on hippocampal volume loss over 1 year in MCI

    PubMed Central

    Chiang, G.C.; Insel, P.S.; Tosun, D.; Schuff, N.; Truran-Sacrey, D.; Raptentsetsang, S.T.; Thompson, P.M.; Reiman, E.M.; Jack, C.R.; Fox, N.C.; Jagust, W.J.; Harvey, D.J.; Beckett, L.A.; Gamst, A.; Aisen, P.S.; Petersen, R.C.; Weiner, M.W.

    2011-01-01

    Background The majority of studies relating amyloid pathology with brain volumes have been cross-sectional. Apolipoprotein E4 (APOE4), a genetic risk factor for Alzheimer’s disease (AD), is also associated with hippocampal volume loss. No studies have considered the effects of amyloid pathology and APOE4 together on longitudinal volume loss. Methods We evaluated whether an abnormal level of cerebrospinal fluid beta-amyloid (CSF Aβ) and APOE4 carrier status were independently associated with greater hippocampal volume loss over 1 year. We then assessed whether APOE4 status and CSF Aβ acted synergistically, testing the significance of an interaction term in the regression analysis. We included 297 participants: 77 cognitively normal (NC), 144 with mild cognitive impairment (MCI), and 76 with AD. Results An abnormal CSF Aβ level was found to be associated with greater hippocampal volume loss over 1 year in each group. APOE4 was associated with hippocampal volume loss only in the NC and MCI groups. APOE4 carriers with abnormal CSF Aβ in the MCI group acted synergistically to produce disproportionately greater volume loss than noncarriers. Conclusion Baseline CSF Aβ predicts progression of hippocampal volume loss. APOE4 carrier status amplifies the degree of neurodegeneration in MCI. Understanding the effect of interactions between genetic risk and amyloid pathology will be important in clinical trials and our understanding of the disease process. PMID:21889115

  4. Cognitive Predictors of Academic Achievement in Young Children 1 Year Following Traumatic Brain Injury

    PubMed Central

    Fulton, John B.; Yeates, Keith Owen; Taylor, H. Gerry; Walz, Nicolay C.; Wade, Shari L.

    2012-01-01

    Objective To examine cognitive predictors of academic achievement in young children with traumatic brain injury (TBI) and orthopedic injury (OI) shortly after injury and 1 year post-injury. Methods Participants included 3 to 6 year old children, 63 with TBI (46 with moderate TBI and 17 with severe TBI) and a comparison group of 80 children with OI. Academic achievement was assessed approximately 1 month and 12 months post injury, using three subtests from the Woodcock-Johnson Tests of Achievement-Third Edition and the School Readiness Composite from the Bracken Basic Concepts Scale-Revised. General intellectual functioning, memory, and executive functions were measured at the initial assessment using standardized tests. Results Hierarchical linear regression was used to predict academic achievement at the initial and 1-year follow-up assessments. Memory and executive functions were significant predictors of academic achievement at both assessments, after controlling for group membership and demographic variables. Executive function remained a significant predictor of some outcomes after taking general intellectual functioning into account. Predictive relationships did not vary across the TBI and OI groups. Similar results were obtained when regression analyses were completed with only TBI participants using the Glasgow Coma Scale (GCS) score as a predictor, although memory and executive functioning were somewhat less robust in predicting academic achievement than before. Conclusions Both memory and executive function predict academic achievement following TBI in preschool children, although some of the associations may be accounted for by general intellectual functioning. PMID:22563873

  5. The value of repeat neuroimaging for epilepsy at a tertiary referral centre: 16 years of experience☆

    PubMed Central

    Winston, Gavin P.; Micallef, Caroline; Kendell, Brian E.; Bartlett, Philippa A.; Williams, Elaine J.; Burdett, Jane L.; Duncan, John S.

    2013-01-01

    Summary Purpose Magnetic resonance imaging (MRI) is the investigation of choice for detecting structural lesions that underlie and may accompany epilepsy. Despite advances in imaging technology, 20–30% of patients with refractory focal epilepsy have normal MRI scans. We evaluated the role of repeated imaging with improved MRI technology – an increase in field strength from 1.5 T to 3 T and superior head coils – in detecting pathology not previously seen. Methods Retrospective review of a large cohort of patients attending a tertiary epilepsy referral centre who underwent MRI at 1.5 T (1995–2004) and subsequently 3 T (2004–2011) with improved head coils. Scan reports were reviewed for the diagnoses and medical notes for the epilepsy classification. Results 804 patients underwent imaging on both scanners, the majority with focal epilepsy (87%). On repeat scanning at 3 T, 37% of scans were normal and 20% showed incidental findings. Positive findings included hippocampal sclerosis (13%), malformations of cortical development (8%), other abnormalities (4%) and previous surgery (18%). A total of 37 (5%) relevant new diagnoses were made on the 3 T scans not previously seen at 1.5 T. The most common new findings were hippocampal sclerosis, focal cortical dysplasia and dysembryoplastic neuroepithelial tumour. These findings affected patient management with several patients undergoing neurosurgery. Conclusions The higher field strength and improved head coils were associated with a clinically relevant increased diagnostic yield from MRI. This highlights the importance of technological advances and suggests that rescanning patients with focal epilepsy and previously negative scans is clinically beneficial. PMID:23538269

  6. Cervical Spine MRI in Abused Infants.

    ERIC Educational Resources Information Center

    Feldman, Kenneth W.; And Others

    1997-01-01

    This study attempted to use cervical spine magnetic resonance imaging (MRI) to detect cord injury in 12 dead children with head injury from child abuse. Eighty percent of children autopsied had small cervical spine hemorrhages; MRI did not identify them and did not identify cord injury in any child studied, indicating that MRI scans are probably…

  7. Magnetic Resonance Imaging (MRI) -- Head

    MedlinePlus

    ... provides detailed images of blood vessels in the brain—often without the need for contrast material. See the MRA page for more information. MRI can detect stroke at a very early stage by mapping the motion of water molecules in the tissue. ...

  8. MRI bone oedema predicts eight year tendon function at the wrist but not the requirement for orthopaedic surgery in rheumatoid arthritis

    PubMed Central

    Zheng, S; Robinson, E; Yeoman, S; Stewart, N; Crabbe, J; Rouse, J; McQueen, F M

    2006-01-01

    Objective To investigate the role of early magnetic resonance imaging (MRI) of the wrist in predicting functional outcome in rheumatoid arthritis. Methods MRI scans of the dominant wrist were scored for synovitis, tendon inflammation, bone oedema, and erosion at first presentation (n = 42), at 1 year (n = 42), and at 6 years (n = 31). At 8 years, clinical reassessment (n = 28) was undertaken. Tendon function was graded 0–3 for movement, tendon sheath swelling, and pain on resistance at nine flexor and extensor tendons of the hand. Hand function was also assessed using the Sollerman grip test. The requirement for joint or tendon surgery by 8 years was determined by telephone survey in 39 of the original 42 patients. Results At 8 years, tendon function was highly correlated with hand function (Sollerman score, R = −0.51, p = 0.005) and global function (health assessment questionnaire score, R = 0.53, p = 0.004). Using a model incorporating baseline and 1 year MRI scores, the MRI bone oedema score was strongly predictive of tendon function at 8 years (χ22 = 15.3, p = 0.0005), as was the MRI bone erosion score (χ22 = 9.23, p = 0.01). Hand function was also predicted by the baseline MRI erosion score (p = 0.02). MRI variables did not predict the requirement for surgery, but patients who had surgery were more likely to show progression of MRI bone erosion scores between baseline and 1 year (p = 0.008). Conclusions Extensive MRI bone oedema and erosions at the wrist in early rheumatoid arthritis predict tendon dysfunction and impaired hand function in the medium term but not the requirement for joint or tendon surgery. PMID:16219706

  9. Two-dimensional quantum repeaters

    NASA Astrophysics Data System (ADS)

    Wallnöfer, J.; Zwerger, M.; Muschik, C.; Sangouard, N.; Dür, W.

    2016-11-01

    The endeavor to develop quantum networks gave rise to a rapidly developing field with far-reaching applications such as secure communication and the realization of distributed computing tasks. This ultimately calls for the creation of flexible multiuser structures that allow for quantum communication between arbitrary pairs of parties in the network and facilitate also multiuser applications. To address this challenge, we propose a two-dimensional quantum repeater architecture to establish long-distance entanglement shared between multiple communication partners in the presence of channel noise and imperfect local control operations. The scheme is based on the creation of self-similar multiqubit entanglement structures at growing scale, where variants of entanglement swapping and multiparty entanglement purification are combined to create high-fidelity entangled states. We show how such networks can be implemented using trapped ions in cavities.

  10. Linear Synchronous Motor Repeatability Tests

    SciTech Connect

    Ward, C.R.

    2002-10-18

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility.

  11. Can Dynamic Contrast-Enhanced MRI (DCE-MRI) and Diffusion-Weighted MRI (DW-MRI) Evaluate Inflammation Disease

    PubMed Central

    Zhu, Jianguo; Zhang, Faming; Luan, Yun; Cao, Peng; Liu, Fei; He, Wenwen; Wang, Dehang

    2016-01-01

    Abstract The aim of the study was to investigate diagnosis efficacy of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in Crohn's disease (CD). To find out the correlations between functional MRI parameters including Ktrans, Kep, Ve, Vp, and apparent diffusion coefficient (ADC) with a serologic biomarker. The relationships between pharmacokinetic parameters and ADC were also studied. Thirty-two patients with CD (22 men, 10 women; mean age: 30.5 years) and 18 healthy volunteers without any inflammatory disease (10 men, 8 women; mean age, 34.11 years) were enrolled into this approved prospective study. Pearson analysis was used to evaluate the correlation between Ktrans, Kep, Ve, Vp, and C-reactive protein (CRP), ADC, and CRP respectively. The diagnostic efficacy of the functional MRI parameters in terms of sensitivity and specificity were analyzed by receiver operating characteristic (ROC) curve analyses. Optimal cut-off values of each functional MRI parameters for differentiation of inflammatory from normal bowel were determined according to the Youden criterion. Mean value of Ktrans in the CD group was significantly higher than that of normal control group. Similar results were observed for Kep and Ve. On the contrary, the ADC value was lower in the CD group than that in the control group. Ktrans and Ve were shown to be correlated with CRP (r = 0.725, P < 0.001; r = 0.533, P = 0.002), meanwhile ADC showed negative correlation with CRP (r = −0.630, P < 0.001). There were negative correlations between the pharmacokinetic parameters and ADC, such as Ktrans to ADC (r = −0.856, P < 0.001), and Ve to ADC (r = −0.451, P = 0.01). The area under the curve (AUC) was 0.994 for Ktrans (P < 0.001), 0.905 for ADC (P < 0.001), 0.806 for Ve (P < 0.001), and 0.764 for Kep (P = 0.002). The cut-off point of the Ktrans was found to be 0.931 min–1. This value provided the best trade-off between

  12. Repeat instability: mechanisms of dynamic mutations.

    PubMed

    Pearson, Christopher E; Nichol Edamura, Kerrie; Cleary, John D

    2005-10-01

    Disease-causing repeat instability is an important and unique form of mutation that is linked to more than 40 neurological, neurodegenerative and neuromuscular disorders. DNA repeat expansion mutations are dynamic and ongoing within tissues and across generations. The patterns of inherited and tissue-specific instability are determined by both gene-specific cis-elements and trans-acting DNA metabolic proteins. Repeat instability probably involves the formation of unusual DNA structures during DNA replication, repair and recombination. Experimental advances towards explaining the mechanisms of repeat instability have broadened our understanding of this mutational process. They have revealed surprising ways in which metabolic pathways can drive or protect from repeat instability.

  13. Patient-centeredness and quality management in Dutch diabetes care organizations after a 1-year intervention

    PubMed Central

    Campmans-Kuijpers, Marjo JE; Lemmens, Lidwien C; Baan, Caroline A; Rutten, Guy EHM

    2016-01-01

    Background More focus on patient-centeredness in care for patients with type 2 diabetes requests increasing attention to diabetes quality management processes on patient-centeredness by managers in primary care groups and outpatient clinics. Although patient-centered care is ultimately determined by the quality of interactions between patients and clinicians at the practice level, it should be facilitated at organizational level too. This nationwide study aimed to assess the state of diabetes quality management on patient-centeredness at organizational level and its possibilities to improve after a tailored intervention. Methods This before–after study compares the quality management on patient-centeredness within Dutch diabetes care groups and outpatient clinics before and after a 1-year stepwise intervention. At baseline, managers of 51 diabetes primary care groups and 28 outpatient diabetes clinics completed a questionnaire about the organization’s quality management program. Patient-centeredness (0%–100%) was operationalized in six subdomains: facilitating self-management support, individualized care plan support, patients’ access to medical files, patient education policy, safeguarding patients’ interests, and formal patient involvement. The intervention consisted of feedback and benchmark and if requested a telephone call and/or a consultancy visit. After 1 year, the managers completed the questionnaire again. The 1-year changes were examined by dependent (non) parametric tests. Results Care groups improved significantly on patient-centeredness (from 47.1% to 53.3%; P=0.002), and on its subdomains “access to medical files” (from 42.0% to 49.4%), and “safeguarding patients’ interests” (from 58.1% to 66.2%). Outpatient clinics, which scored higher at baseline (66.7%) than care groups, did not improve on patient-centeredness (65.6%: P=0.54) or its subdomains. “Formal patient involvement” remained low in both care groups (23.2%) and

  14. Syntactic Priming and the Lexical Boost Effect during Sentence Production and Sentence Comprehension: An fMRI Study

    ERIC Educational Resources Information Center

    Segaert, Katrien; Kempen, Gerard; Petersson, Karl Magnus; Hagoort, Peter

    2013-01-01

    Behavioral syntactic priming effects during sentence comprehension are typically observed only if both the syntactic structure and lexical head are repeated. In contrast, during production syntactic priming occurs with structure repetition alone, but the effect is boosted by repetition of the lexical head. We used fMRI to investigate the neuronal…

  15. Unfolding a linker between helical repeats.

    PubMed

    Ortiz, Vanessa; Nielsen, Steven O; Klein, Michael L; Discher, Dennis E

    2005-06-10

    In many multi-repeat proteins, linkers between repeats have little secondary structure and place few constraints on folding or unfolding. However, the large family of spectrin-like proteins, including alpha-actinin, spectrin, and dystrophin, share three-helix bundle, spectrin repeats that appear in crystal structures to be linked by long helices. All of these proteins are regularly subjected to mechanical stress. Recent single molecule atomic force microscopy (AFM) experiments demonstrate not only forced unfolding but also simultaneous unfolding of tandem repeats at finite frequency, which suggests that the contiguous helix between spectrin repeats can propagate a cooperative helix-to-coil transition. Here, we address what happens atomistically to the linker under stress by steered molecular dynamics simulations of tandem spectrin repeats in explicit water. The results for alpha-actinin repeats reveal rate-dependent pathways, with one pathway showing that the linker between repeats unfolds, which may explain the single-repeat unfolding pathway observed in AFM experiments. A second pathway preserves the structural integrity of the linker, which explains the tandem-repeat unfolding event. Unfolding of the linker begins with a splay distortion of proximal loops away from hydrophobic contacts with the linker. This is followed by linker destabilization and unwinding with increased hydration of the backbone. The end result is an unfolded helix that mechanically decouples tandem repeats. Molecularly detailed insights obtained here aid in understanding the mechanical coupling of domain stability in spectrin family proteins.

  16. Comparison of dynamic contrast enhanced MRI and Doppler ultrasound in the pre-operative assessment of the portal venous system.

    PubMed

    Naik, K S; Ward, J; Irving, H C; Robinson, P J

    1997-01-01

    The purpose of this study was to compare dynamic contrast enhanced MRI (DCEMR) with Doppler ultrasound (US) in the assessment of portal venous anatomy and to analyse the causes of discrepancy. Over a 1 year period, 97 patients undergoing assessment prior to hepatic surgery underwent imaging of the liver and portal venous system using US with colour and spectral Doppler and MRI with axial T2 weighted spin echo (SE) and coronal oblique T1 weighted rapid gradient echo (GRE) imaging before and immediately after bolus injection of Gd-DTPA (0.1 mmol kg-1). When the US and MRI findings were discrepant, the images were reviewed by two observers and compared with surgical findings. US and DCEMR were concordant in 90 patients (portal vein patent in 80, occluded in 10). In three patients with cirrhosis and gross ascites the portal vein was reported as occluded on US and patent on MRI; surgery confirmed the MRI findings. In one patient the portal vein was patient on US but not on MRI, but there was a 3 week interval between the examinations. In three patients the portal vein was patent on US, but MRI detected occlusion of intrahepatic portal vein branches in two, and encasement of an intrahepatic branch in the third case. Spontaneous splenorenal shunts were seen in 15 patients only on MRI; varices were seen in 39 patients on MRI and in 22 patients on US. Both US and DCEMR contribute to the pre-operative assessment of the portal venous system. MRI provides additional information over US in assessing intrahepatic portal branches and detecting varices and splenorenal shunts, and is recommended for all surgical candidates and in patients with abnormal portal venous anatomy and equivocal US findings.

  17. Comprehensive brain MRI segmentation in high risk preterm newborns.

    PubMed

    Yu, Xintian; Zhang, Yanjie; Lasky, Robert E; Datta, Sushmita; Parikh, Nehal A; Narayana, Ponnada A

    2010-11-08

    Most extremely preterm newborns exhibit cerebral atrophy/growth disturbances and white matter signal abnormalities on MRI at term-equivalent age. MRI brain volumes could serve as biomarkers for evaluating the effects of neonatal intensive care and predicting neurodevelopmental outcomes. This requires detailed, accurate, and reliable brain MRI segmentation methods. We describe our efforts to develop such methods in high risk newborns using a combination of manual and automated segmentation tools. After intensive efforts to accurately define structural boundaries, two trained raters independently performed manual segmentation of nine subcortical structures using axial T2-weighted MRI scans from 20 randomly selected extremely preterm infants. All scans were re-segmented by both raters to assess reliability. High intra-rater reliability was achieved, as assessed by repeatability and intra-class correlation coefficients (ICC range: 0.97 to 0.99) for all manually segmented regions. Inter-rater reliability was slightly lower (ICC range: 0.93 to 0.99). A semi-automated segmentation approach was developed that combined the parametric strengths of the Hidden Markov Random Field Expectation Maximization algorithm with non-parametric Parzen window classifier resulting in accurate white matter, gray matter, and CSF segmentation. Final manual correction of misclassification errors improved accuracy (similarity index range: 0.87 to 0.89) and facilitated objective quantification of white matter signal abnormalities. The semi-automated and manual methods were seamlessly integrated to generate full brain segmentation within two hours. This comprehensive approach can facilitate the evaluation of large cohorts to rigorously evaluate the utility of regional brain volumes as biomarkers of neonatal care and surrogate endpoints for neurodevelopmental outcomes.

  18. Diversion Alert: 1-Year Evaluation Across Northern New England, 2013–2014

    PubMed Central

    Desrosiers, Clare

    2016-01-01

    This report describes Diversion Alert, a unique online tool aimed at reducing misuse and diversion of prescription drugs, and reports the results of a 1-year evaluation of Diversion Alert’s impact in Maine. We used a quasi-experimental research design to compare survey data in Maine with those of neighboring states (New Hampshire and Vermont, 2013 and 2014). Compared with their counterparts in New Hampshire and Vermont who did not use Diversion Alert, prescribers and pharmacists in Maine who used Diversion Alert increased their communication with patients and other providers involved in their patients’ care, became aware of patients arrested for prescription drugs possession or diversion, used best practices associated with prevention or detection of addiction and diversion more frequently, and attributed positive changes in their prescribing practices to Diversion Alert. In combination with other state and federal programs, Diversion Alert may be an effective tool to help prevent the misuse of opioid medications. PMID:27880633

  19. Cognitive dysfunction at baseline predicts symptomatic 1-year outcome in first-episode schizophrenics.

    PubMed

    Moritz, S; Krausz, M; Gottwalz, E; Lambert, M; Perro, C; Ganzer, S; Naber, D

    2000-01-01

    The present study addresses the consequences of cognitive disturbances on symptomatic outcome. Fifty-three first-episode schizophrenics were reassessed (n = 32) 1 year after admission. Simple regression analyses revealed that several self-perceived cognitive deficits at baseline as measured with the Frankfurt Complaint Questionnaire significantly predicted increased Brief Psychiatric Rating Scale global scores at follow-up (p = 0.05 to p = 0.005). A stepwise regression analysis proved memory dysfunction to be the strongest predictor of symptomatic worsening (p = 0.005). It is suggested that the exploration and treatment of neuropsychological deficits in schizophrenia is of great clinical importance with regard to its impact on both functional and symptomatic outcome in schizophrenia.

  20. Whooping cough in South-East Romania: a 1-year study.

    PubMed

    Dinu, Sorin; Guillot, Sophie; Dragomirescu, Cristiana Cerasella; Brun, Delphine; Lazăr, Stefan; Vancea, Geta; Ionescu, Biatrice Mariana; Gherman, Mariana Felicia; Bjerkestrand, Andreea-Florina-Dana; Ungureanu, Vasilica; Guiso, Nicole; Damian, Maria

    2014-03-01

    The incidence of whooping cough in Romania is substantially underestimated, and, as noted by the health authorities, this is mostly due to the lack of both awareness and biological diagnosis. We conducted a 1-year study in Bucharest in order to assess the circulation of Bordetella pertussis, the main etiological agent of whooping cough. Fifty-one subjects suspected of whooping cough were enrolled. Culture, real-time PCR, and enzyme-linked immunosorbent assay were used for laboratory diagnosis. Whooping cough patients (63%) were distributed among all age groups, and most were unvaccinated, incompletely vaccinated, or had been vaccinated more than 5 years previously. Bordetella holmesii DNA was detected in 22% of the bordetellosis cases; these patients included adults; teenagers; and, surprisingly, young children. B. pertussis isolates were similar to the clinical isolates currently circulating elsewhere in Europe. One isolate does not express pertactin, an antigen included in some acellular pertussis vaccines.

  1. Shock-wave therapy for tennis and golfer's elbow--1 year follow-up.

    PubMed

    Krischek, O; Hopf, C; Nafe, B; Rompe, J D

    1999-01-01

    Thirty patients with chronic medial epicondylitis were treated with low-energy shock waves. They received 500 impulses of 0.08 mJ/mm2 three times at weekly intervals. At 1 year follow-up examinations were performed. According to the Verhaar criteria, only seven patients reached excellent or good results. In eight cases a fair outcome was recorded, and in 14 patients the outcome was poor. Only six patients were satisfied with the treatment. The average relief of pain was 32%. These data were significantly worse than for identically treated patients with chronic tennis elbow. Thus, the question arises as to whether extracorporal shock-wave therapy is indicated in medial epicondylitis.

  2. A Semiparametric Bayesian Model for Repeatedly Repeated Binary Outcomes

    PubMed Central

    Quintana, Fernando A.; Müller, Peter; Rosner, Gary L.; Relling, Mary V.

    2009-01-01

    Summary We discuss the analysis of data from single nucleotide polymorphism (SNP) arrays comparing tumor and normal tissues. The data consist of sequences of indicators for loss of heterozygosity (LOH) and involve three nested levels of repetition: chromosomes for a given patient, regions within chromosomes, and SNPs nested within regions. We propose to analyze these data using a semiparametric model for multi-level repeated binary data. At the top level of the hierarchy we assume a sampling model for the observed binary LOH sequences that arises from a partial exchangeability argument. This implies a mixture of Markov chains model. The mixture is defined with respect to the Markov transition probabilities. We assume a nonparametric prior for the random mixing measure. The resulting model takes the form of a semiparametric random effects model with the matrix of transition probabilities being the random effects. The model includes appropriate dependence assumptions for the two remaining levels of the hierarchy, i.e., for regions within chromosomes and for chromosomes within patient. We use the model to identify regions of increased LOH in a dataset coming from a study of treatment-related leukemia in children with an initial cancer diagnostic. The model successfully identifies the desired regions and performs well compared to other available alternatives. PMID:19746193

  3. Enteroaggregative Escherichia coli in Daycare—A 1-Year Dynamic Cohort Study

    PubMed Central

    Hebbelstrup Jensen, Betina; Stensvold, Christen R.; Struve, Carsten; Olsen, Katharina E. P.; Scheutz, Flemming; Boisen, Nadia; Röser, Dennis; Andreassen, Bente U.; Nielsen, Henrik V.; Schønning, Kristian; Petersen, Andreas M.; Krogfelt, Karen A.

    2016-01-01

    Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier-status in children in industrialized countries warrants clarification. To investigate the pathological significance of an EAEC carrier-state in the industrialized countries, we designed a 1-year dynamic cohort study and performed follow-up every second month, where the study participants submitted a stool sample and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0–6 years were followed in a cohort study, in the period between 2009 and 2013. This is the first investigation of the incidence and pathological significance of EAEC in Danish children attending daycare facilities. Conventional microbiological detection of enteric pathogens was performed at Statens Serum Institute, Copenhagen, Denmark, and at Hvidovre Hospital, Copenhagen, Denmark. Parents completed questionnaires regarding gastrointestinal symptoms. The EAEC strains were further characterized by serotyping, phylogenetic analysis, and susceptibility testing. EAEC was detected in 25 (14%) of the children during the observational period of 1 year. One or more gastrointestinal symptoms were reported from 56% of the EAEC-positive children. Diarrhea was reported in six (24%) of the EAEC positive children, but no cases of weight loss, and general failure to thrive were observed. The EAEC strains detected comprised a large number of different serotypes, confirming the genetic heterogeneity of this pathotype. EAEC was highly prevalent (n = 25, 14%) in Danish children in daycare centers and was accompanied by gastrointestinal symptoms in

  4. Sustained sympathetic and blood pressure reduction 1 year after renal denervation in patients with resistant hypertension.

    PubMed

    Hering, Dagmara; Marusic, Petra; Walton, Antony S; Lambert, Elisabeth A; Krum, Henry; Narkiewicz, Krzysztof; Lambert, Gavin W; Esler, Murray D; Schlaich, Markus P

    2014-07-01

    Renal denervation (RDN) reduces muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in resistant hypertension. Although a persistent BP-lowering effect has been demonstrated, the long-term effect on MSNA remains elusive. We investigated whether RDN influences MSNA over time. Office BP and MSNA were obtained at baseline, 3, 6, and 12 months after RDN in 35 patients with resistant hypertension. Office BP averaged 166±22/88±19 mm Hg, despite the use of an average of 4.8±2.1 antihypertensive drugs. Baseline MSNA was 51±11 bursts/min ≈2- to 3-fold higher than the level observed in healthy controls. Mean office systolic and diastolic BP significantly decreased by -12.6±18.3/-6.5±9.2, -16.1±25.6/-8.6±12.9, and -21.2±29.1/-11.1±12.9 mm Hg (P<0.001 for both systolic BP and diastolic BP) with RDN at 3-, 6-, and 12-month follow-up, respectively. MSNA was reduced by -8±12, -6±12, and -6±11 bursts/min (P<0.01) at 3-, 6-, and 12-month follow-up. The reduction in MSNA was maintained, despite a progressive fall in BP over time. No such changes were observed in 7 control subjects at 6-month follow-up. These findings confirm previous reports on the favorable effects of RDN on elevated BP and demonstrate sustained reduction of central sympathetic outflow ≤1-year follow-up in patients with resistant hypertension and high baseline MSNA. These observations are compatible with the hypothesis of a substantial contribution of afferent renal nerve signaling to increased BP in resistant hypertension and argue against a relevant reinnervation at 1 year after procedure.

  5. Minimally invasive facet restoration implant for chronic lumbar zygapophysial pain: 1-year outcomes

    PubMed Central

    2014-01-01

    Background The zygapophysial (facet) joint is the primary pain generator in one third of chronic low back pain cases. Current treatment options include temporarily palliative nonsurgical approaches, facet injections, radiofrequency denervation, and, rarely, lumbar arthrodesis. The purpose of this study was to assess the safety and effectiveness of a minimally invasive implant intended to restore facet joint function in patients with chronic lumbar facetogenic pain. Methods This prospective, multi-center feasibility study enrolled patients with confirmed lumbar facetogenic joint pain at 1 or 2 levels who underwent at least 6 months of unsuccessful nonoperative care. Patients received a minimally invasive implant (Glyder® Facet Restoration Device, Zyga Technology, Inc., Minnetonka, MN) intended to restore facet joint function while preserving the native anatomy. Main outcomes included back pain severity using a visual analogue scale, back-specific disability using the Oswestry Disability Index (ODI), and adverse events adjudicated by an independent Clinical Events Committee. Results Of 40 enrolled patients, 37 patients received the facet restoration implant and 34 patients had complete 1-year follow-up data available. Over the 1-year follow-up period, back pain severity decreased 41% and ODI decreased 34%, on average. Freedom from a device- or procedure-related serious adverse event through 1 year was 84%. Implant migration was observed in 3 patients and implant expulsion from the facet joint occurred in 3 patients. In total, 2 (5.4%) patients underwent implant removal through 1 year post-treatment. Conclusions A minimally invasive facet restoration implant is a promising treatment option in select patients with chronic lumbar zygapophysial pain who have exhausted nonsurgical treatments, with therapeutic benefit persisting at 1 year follow-up. PMID:26628910

  6. The Effect of Clozapine on Hematological Indices: A 1-Year Follow-Up Study.

    PubMed

    Lee, Jimmy; Takeuchi, Hiroyoshi; Fervaha, Gagan; Powell, Valerie; Bhaloo, Amaal; Bies, Robert; Remington, Gary

    2015-10-01

    Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia and is linked to a need for mandatory hematological monitoring. Besides agranulocytosis, other hematological aberrations have resulted in premature termination in some cases. Considering clozapine's role in immunomodulation, we proceeded to investigate the impact of clozapine on the following 3 main hematological cell lines: red blood cells, platelets, white blood cells (WBCs), and its differential counts. Data were extracted from patients initiated on clozapine between January 2009 and December 2010 at a single hospital. Patients with a preclozapine complete blood count, who were receiving clozapine during the 1-year follow-up period, were included in the present investigation. Counts of red blood cells, platelets, WBC, and its differential including neutrophils, lymphocytes, monocytes, eosinophils, and basophils were extracted and trajectories plotted. One hundred one patients were included in this study and 66 remained on clozapine at the end of 1 year. There was a synchronized but transient increase in WBC, neutrophils, monocytes, eosinophils, basophils, and platelets beginning as early as the first week of clozapine treatment. There were no cases of agranulocytosis reported in this sample, and five developed neutropenia. A spike in neutrophils immediately preceded the onset of neutropenia in three of the five. The cumulative incidence rates were 48.9% for neutrophilia, 5.9% for eosinophilia, and 3% each for thrombocytosis and thrombocytopenia. Early hematological aberrations are visible across a range of cell lines, primarily of the myeloid lineage. These disturbances are transient and are probably related to clozapine's immunomodulatory properties. We do not suggest discontinuing clozapine as a consequence of the observed aberrations.

  7. Persistent problems 1 year after mild traumatic brain injury: a longitudinal population study in New Zealand

    PubMed Central

    Theadom, Alice; Parag, Varsha; Dowell, Tony; McPherson, Kathryn; Starkey, Nicola; Barker-Collo, Suzanne; Jones, Kelly; Ameratunga, Shanthi; Feigin, Valery L

    2016-01-01

    Background Mild traumatic brain injury (mTBI) is a common problem in general practice settings, yet previous research does not take into account those who do not attend hospital after injury. This is important as there is evidence that effects may be far from mild. Aim To determine whether people sustain any persistent effects 1 year after mTBI, and to identify the predictors of health outcomes. Design and setting A community-based, longitudinal population study of an mTBI incidence cohort (n = 341) from a mixed urban and rural region (Hamilton and Waikato Districts) of the North Island of New Zealand (NZ). Method Adults (>16 years) completed assessments of cognitive functioning, global functioning, post-concussion symptoms, mood, and quality of life over the year after injury. Results Nearly half of participants (47.9%) reported experiencing four or more post-concussion symptoms 1 year post-injury. Additionally, 10.9% of participants revealed very low cognitive functioning. Levels of anxiety, depression, or reduced quality of life were comparable with the general population. Having at least one comorbidity, history of brain injury, living alone, non-white ethnic group, alcohol and medication use, and being female were significant predictors of poorer outcomes at 12 months. Conclusion Although some people make a spontaneous recovery after mTBI, nearly half continue to experience persistent symptoms linked to their injury. Monitoring of recovery from mTBI may be needed and interventions provided for those experiencing persistent difficulties. Demographic factors and medical history should be taken into account in treatment planning. PMID:26719482

  8. Perinatal dioxin exposure and the neurodevelopment of Vietnamese toddlers at 1 year of age.

    PubMed

    Pham, Tai The; Nishijo, Muneko; Nguyen, Anh Thi Nguyet; Tran, Nghi Ngoc; Van Hoang, Luong; Tran, Anh Hai; Nguyen, Trung Viet; Nishijo, Hisao

    2015-12-01

    Dioxin concentrations remain elevated in both the environment and in humans residing near former US Air Force bases in South Vietnam. This may potentially have adverse health effects, particularly on infant neurodevelopment. We followed 214 infants whose mothers resided in a dioxin-contaminated area in Da Nang, Vietnam, from birth until 1 year of age. Perinatal exposure to dioxins was estimated from toxic equivalent (TEQ) levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs-TEQ), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TetraCDD) concentrations in breast milk. In infants, daily dioxin intake (DDI) was used as an index of postnatal exposure through breastfeeding. Neurodevelopment of toddlers was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). No significant differences in neurodevelopmental scores were exhibited for cognitive, language or motor functions between four exposure groups of PCDDs/Fs-TEQ or 2,3,7,8-TetraCDD. However, social-emotional scores were decreased in the high PCDDs/Fs-TEQ group and the high 2,3,7,8-TetraCDD group compared with those with mild exposure, after adjusting for confounding factors. Cognitive scores in the mild, moderate, and high DDI groups were significantly higher than those in low DDI group, but there were no differences in cognitive scores among the three higher DDI groups. These results suggest that perinatal exposure to dioxins may affect social-emotional development of 1-year-old toddlers, without diminishing global neurodevelopmental function.

  9. Identifying groups at risk for 1-year membership termination from a fitness center at enrollment.

    PubMed

    Hooker, Stephanie A; Ross, Kaile M; Ranby, Krista W; Masters, Kevin S; Peters, John C; Hill, James O

    2016-12-01

    The vast majority of Americans do not engage in adequate regular physical activity despite its well-known health benefits. Even when individuals attempt to become more active by joining a fitness center, estimates suggest that nearly half terminate their membership within the first 6 months. A better understanding of who is at risk for early membership termination upon joining may help researchers develop targeted interventions to improve the likelihood that individuals will successfully maintain memberships and physical activity. This study's purpose was to identify, based on a wellness assessment (WA) used in fitness centers, individuals at risk for fitness membership termination prior to 1-year. Center members (N = 441; Mage = 41.9, SD = 13.1; 74.4% female) completed a comprehensive WA of stress, life satisfaction, physical fitness, metabolic health, and sleep quality at the beginning of their memberships and were followed for one year. Latent class analyses utilized the WA to identify four groups: (a) healthy, (b) unhealthy, (c) poor psychological wellness, and (d) poor physical wellness. Participants in the poor psychological wellness group (OR = 2.24, p = 0.007) and the unhealthy group (OR = 2.40, p = 0.037) were significantly more likely to terminate their memberships at 1-year as compared to the healthy group. Participants with poor physical wellness visited the fitness center less frequently than healthy participants (p < 0.01). Results suggest that poor psychological wellness is a risk factor for terminating memberships, whereas poor physical wellness is not. Future studies should replicate these latent classes and develop targeted interventions to address psychological wellness as a method to improve fitness membership retention.

  10. Glomerular filtration rate in patients with atrial fibrillation and 1-year outcomes

    PubMed Central

    Boriani, Giuseppe; Laroche, Cécile; Diemberger, Igor; Popescu, Mircea Ioachim; Rasmussen, Lars Hvilsted; Petrescu, Lucian; Crijns, Harry J. G. M.; Tavazzi, Luigi; Maggioni, Aldo P.; Lip, Gregory Y. H.

    2016-01-01

    We assessed 1-year outcomes in patients with atrial fibrillation enrolled in the EurObservational Research Programme AF General Pilot Registry (EORP-AF), in relation to kidney function, as assessed by glomerular filtration rate (eGFR). In a cohort of 2398 patients (median age 69 years; 61% male), eGFR (ml/min/1.73 m2) calculated using the CKD-EPI formula was ≥80 in 35.1%, 50–79 in 47.2%, 30–49 in 13.9% and <30 in 3.7% of patients. In a logistic regression analysis, eGFR category was an independent predictor of stroke/TIA or death, with elevated odds ratios associated with severe to mild renal impairment, ie. eGFR < 30 ml/min/1.73 m2 [OR 3.641, 95% CI 1.572–8.433, p < 0.0001], 30–49 ml/min/1.73 m2 [OR 3.303, 95% CI 1.740–6.270, p = 0.0026] or 50–79 ml/min/1.73 m2 [OR 2.094, 95% CI 1.194–3.672, p = 0.0003]. The discriminant capability for the risk of death was tested among various eGFR calculation algorithms: the best was the Cockcroft-Gault equation adjusted for BSA, followed by Cockcroft-Gault equation, and CKD-EPI equation, while the worst was the MDRD equation. In conclusion in this prospective observational registry, renal function was a major determinant of adverse outcomes at 1 year, and even mild or moderate renal impairments were associated with an increased risk of stroke/TIA/death. PMID:27466080

  11. Safety and efficacy of nurse-controlled analgesia in patients less than 1 year of age

    PubMed Central

    Walia, Hina; Tumin, Dmitry; Wrona, Sharon; Martin, David; Bhalla, Tarun; Tobias, Joseph D

    2016-01-01

    Background The management of acute pain presents unique challenges in the younger pediatric population. Although patient-controlled devices are frequently used in patients ≥6 years of age, alternative modes of analgesic delivery are needed in infants. Objective To examine the safety and efficacy of nurse-controlled analgesia (NCA) in neonates less than 1 year of age. Methods Data from patients <1 year of age receiving NCA as ordered by the Acute Pain Service at our institution were collected over a 5-year period and reviewed retrospectively. The primary outcomes were activation of the institution’s Rapid Response Team (RRT) or Code Blue, signifying severe adverse events. Pain score after NCA initiation was a secondary outcome. Results Among 338 girls and 431 boys, the most common opioid used for NCA was fentanyl, followed by morphine and hydromorphone. There were 39 (5%) cases involving RRT or Code Blue activation, of which only one (Code Blue) was activated due to a complication of NCA (apnea). Multivariable logistic regression demonstrated morphine NCA to be associated with greater odds of RRT activation (OR=3.29, 95% CI=1.35, 8.03, P=0.009) compared to fentanyl NCA. There were no statistically significant differences in pain scores after NCA initiation across NCA agents. Conclusion NCA is safe in neonates and infants, with comparable efficacy demonstrated for the three agents used. The elevated incidence of RRT activation in patients receiving morphine suggests caution in its use and consideration of alternative agents in this population. PMID:27358574

  12. Evaluation of orthodontic treatment after 1 year of retention--a randomized controlled trial.

    PubMed

    Edman Tynelius, G; Bondemark, L; Lilja-Karlander, E

    2010-10-01

    The aim of this study was to use a randomized controlled trial methodology to evaluate and compare three different retention methods. The capacity of the retention methods to retain orthodontic treatment results was in this first phase analysed on a short-term basis, i.e. after 1 year of retention. The subjects were recruited from adolescents undergoing fixed appliance treatment at an orthodontic clinic in the National Health Service (NHS) in Sweden between 2001 and 2007. Seventy-five patients (45 girls and 30 boys with a mean age of 14.4 years at the start of retention) were randomized into three retention systems; a vacuum-formed retainer in the maxilla and bonded canine-to-canine retainer in the mandible (group V-CTC), a vacuum-formed retainer in the maxilla combined with stripping of the 10 proximal surfaces of the lower mandibular anterior teeth (group V-S), and a prefabricated positioner covering the teeth in the maxilla and mandible (group P). The main outcome measures were: Little's irregularity index (LII), intercanine and intermolar width, arch length, overjet, and overbite. Registrations were made before orthodontic treatment, when the fixed orthodontic appliance was removed, and after 12 months in retention. Differences in means between groups were tested by one-way analysis of variance. After 1 year of retention, no clinically significant difference in retention capacity was found between the three retention methods. Small but significant differences (P < 0.05) were observed between the V-CTC and V-S groups regarding mandibular canine width, mandibular arch length, and overbite. In group P, two patients failed to co-operate.

  13. Transient CNS responses to repeated binge ethanol treatment

    PubMed Central

    Zahr, Natalie M; Rohlfing, Torsten; Mayer, Dirk; Luong, Richard; Sullivan, Edith V; Pfefferbaum, Adolf

    2016-01-01

    Adaptive changes occur in response to repeated exposure to drugs. Although ethanol (EtOH) is known to induce pharmacokinetic tolerance, the effects of EtOH on in vivo, magnetic resonance (MR)-detectable brain measures across repeated exposures have not previously been reported. Of 28 rats weighing 341±22g at baseline, 15 were assigned to the EtOH group and 13 to the control (Ctrl) group. EtOH animals were exposed to 5 cycles of 4-days of EtOH treatment followed by 10 days of recovery. Rats in both groups had structural MR imaging (MRI) scans and whole brain MR spectroscopy (MRS) at baseline, immediately following each binge period, and after each recovery period (total=11 MR scans per rat). Average blood alcohol levels (BALs) across each of the 5, 4-day binge periods were 298, 300, 301, 312, 318 mg/dL. Cerebrospinal fluid (CSF) volumes of the lateral ventricles and cisterns showed enlargement with each binge EtOH exposure but recovery with each abstinence period. Similarly, changes to MRS metabolites were transient: levels of N-acetyl aspartate (NAA) and total creatine (tCr) decreased, while those of choline-containing compounds (Cho) and glutamate/glutamine (Glx) increased with each binge EtOH exposure cycle, but also recovered during each abstinence period. The directionality of changes in response to EtOH were in expected directions based on previous, single-binge EtOH exposure experiments, but the current results do not provide support for accruing pathology with repeated binge EtOH exposure. PMID:26283309

  14. Comparison of scar thickness measurements using trans-vaginal sonography and MRI in cases of pregnancy with previous caesarean section. Do they correlate with actual scar thickness?

    PubMed

    Singh, N; Tripathi, R; Mala, Y M; Dixit, R; Tyagi, S; Batra, A

    2013-11-01

    The aim of this study was to evaluate scar thickness in cases of pregnancy with previous caesarean section, by trans-vaginal sonography (TVS) and magnetic resonance imaging (MRI), and to correlate precision of radiologically-measured scar thickness with actual measurement of scar thickness. A total of 35 pregnant patients with previous caesarean section planned for elective caesarean section, were evaluated prospectively. Their scar thickness was measured by TVS and MRI on the day of elective repeat caesarean section. These measurements were correlated with each other and with scar thickness measured during elective repeat caesarean section by using a caliper. The correlation coefficients between scar thickness measured by TVS and MRI with peroperative evaluation with a caliper, were +0.72 and +0.59, respectively. The study concluded that as MRI is a costlier modality and TVS has better correlation coefficient with actual scar thickness, TVS can be considered to be the better modality for antenatal scar thickness measurement.

  15. Advances in Clinical PET/MRI Instrumentation.

    PubMed

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils.

  16. Integration of DCE-MRI and DW-MRI Quantitative Parameters for Breast Lesion Classification

    PubMed Central

    Fusco, Roberta; Sansone, Mario; Filice, Salvatore; Granata, Vincenza; Catalano, Orlando; Amato, Daniela Maria; Di Bonito, Maurizio; D'Aiuto, Massimiliano; Capasso, Immacolata; Rinaldo, Massimo; Petrillo, Antonella

    2015-01-01

    Objective. The purpose of our study was to evaluate the diagnostic value of an imaging protocol combining dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in patients with suspicious breast lesions. Materials and Methods. A total of 31 breast lesions (15 malignant and 16 benign proved by histological examination) in 26 female patients were included in this study. For both DCE-MRI and DW-MRI model free and model based parameters were computed pixel by pixel on manually segmented ROIs. Statistical procedures included conventional linear analysis and more advanced techniques for classification of lesions in benign and malignant. Results. Our findings indicated no strong correlation between DCE-MRI and DW-MRI parameters. Results of classification analysis show that combining of DCE parameters or DW-MRI parameter, in comparison of single feature, does not yield a dramatic improvement of sensitivity and specificity of the two techniques alone. The best performance was obtained considering a full combination of all features. Moreover, the classification results combining all features are dominated by DCE-MRI features alone. Conclusion. The combination of DWI and DCE-MRI does not show a potential to dramatically increase the sensitivity and specificity of breast MRI. DCE-MRI alone gave the same performance as in combination with DW-MRI. PMID:26339597

  17. A Case of West Nile Encephalitis That Develops into a Disease of Deep White Matter on MRI over a Two-Week Span

    PubMed Central

    Liu, Antonio

    2016-01-01

    We present a case of serologically proved West Nile encephalitis. This patient had a normal MRI on admission. Given that the patient's clinical picture had worsened during her admission, a repeat MRI was performed, which demonstrated diffuse disease in the deep white matter of the brain. This is a case of West Nice encephalitis presenting as a disease of deep white matter that developed over a two-week span. PMID:27703823

  18. A MRI-CT prostate registration using sparse representation technique

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Jani, Ashesh B.; Rossi, Peter J.; Mao, Hui; Curran, Walter J.; Liu, Tian

    2016-03-01

    Purpose: To develop a new MRI-CT prostate registration using patch-based deformation prediction framework to improve MRI-guided prostate radiotherapy by incorporating multiparametric MRI into planning CT images. Methods: The main contribution is to estimate the deformation between prostate MRI and CT images in a patch-wise fashion by using the sparse representation technique. We assume that two image patches should follow the same deformation if their patch-wise appearance patterns are similar. Specifically, there are two stages in our proposed framework, i.e., the training stage and the application stage. In the training stage, each prostate MR images are carefully registered to the corresponding CT images and all training MR and CT images are carefully registered to a selected CT template. Thus, we obtain the dense deformation field for each training MR and CT image. In the application stage, for registering a new subject MR image with the same subject CT image, we first select a small number of key points at the distinctive regions of this subject CT image. Then, for each key point in the subject CT image, we extract the image patch, centered at the underlying key point. Then, we adaptively construct the coupled dictionary for the underlying point where each atom in the dictionary consists of image patches and the respective deformations obtained from training pair-wise MRI-CT images. Next, the subject image patch can be sparsely represented by a linear combination of training image patches in the dictionary, where we apply the same sparse coefficients to the respective deformations in the dictionary to predict the deformation for the subject MR image patch. After we repeat the same procedure for each subject CT key point, we use B-splines to interpolate a dense deformation field, which is used as the initialization to allow the registration algorithm estimating the remaining small segment of deformations from MRI to CT image

  19. Modeling Repeatedly Flaring δ Sunspots

    NASA Astrophysics Data System (ADS)

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-01

    Active regions (ARs) appearing on the surface of the Sun are classified into α , β , γ , and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  20. Modeling Repeatedly Flaring δ Sunspots.

    PubMed

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-11

    Active regions (ARs) appearing on the surface of the Sun are classified into α, β, γ, and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  1. Trinucleotide Repeats: A Structural Perspective

    PubMed Central

    Almeida, Bruno; Fernandes, Sara; Abreu, Isabel A.; Macedo-Ribeiro, Sandra

    2013-01-01

    Trinucleotide repeat (TNR) expansions are present in a wide range of genes involved in several neurological disorders, being directly involved in the molecular mechanisms underlying pathogenesis through modulation of gene expression and/or the function of the RNA or protein it encodes. Structural and functional information on the role of TNR sequences in RNA and protein is crucial to understand the effect of TNR expansions in neurodegeneration. Therefore, this review intends to provide to the reader a structural and functional view of TNR and encoded homopeptide expansions, with a particular emphasis on polyQ expansions and its role at inducing the self-assembly, aggregation and functional alterations of the carrier protein, which culminates in neuronal toxicity and cell death. Detail will be given to the Machado-Joseph Disease-causative and polyQ-containing protein, ataxin-3, providing clues for the impact of polyQ expansion and its flanking regions in the modulation of ataxin-3 molecular interactions, function, and aggregation. PMID:23801983

  2. Repeat radiation synovectomy with dysprosium 165-ferric hydroxide macroaggregates in rheumatoid knees unresponsive to initial injection

    SciTech Connect

    Vella, M.; Zuckerman, J.D.; Shortkroff, S.; Venkatesan, P.; Sledge, C.B.

    1988-06-01

    Because of failure to fully respond to an initial intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates, 17 patients with seropositive rheumatoid arthritis underwent repeat radiation synovectomy using this agent. Of the 13 patients who were evaluated 1 year later, 54% (7 knees) had good results, 31% (4 knees) had fair results, and 15% (2 knees) had poor results. The initial lack of significant benefit from radiation synovectomy did not appear to preclude a favorable response to a second injection.

  3. Multimodal MRI of experimental stroke

    PubMed Central

    Duong, Timothy Q

    2014-01-01

    Stroke is the fourth leading cause of death and the leading cause of long-term disability in the United States. Brain imaging data from experimental stroke models and stroke patients have shown that there is often a gradual progression of potentially reversible ischemic injury toward infarction. Reestablishing tissue perfusion and/or treating with neuroprotective drugs in a timely fashion are expected to salvage some ischemic tissues. Diffusion-weighted imaging based on magnetic resonance imaging (MRI) in which contrast is based on water motion can detect ischemic injury within minutes after onsets, whereas computed tomography and other imaging modalities fail to detect stroke injury for at least a few hours. Along with quantitative perfusion imaging, the perfusion-diffusion mismatch which approximates the ischemic penumbra could be imaged non-invasively. This review describes recent progresses in the development and application of multimodal MRI and image analysis techniques to study ischemic tissue at risk in experimental stroke in rats. PMID:24323751

  4. Vertebral Augmentation with Nitinol Endoprosthesis: Clinical Experience in 40 Patients with 1-Year Follow-up

    SciTech Connect

    Anselmetti, Giovanni Carlo; Manca, Antonio; Marcia, Stefano; Chiara, Gabriele; Marini, Stefano; Baroud, Gamal; Regge, Daniele; Montemurro, Filippo

    2013-05-08

    PurposeThis study was designed to assess the clinical outcomes of patients treated by vertebral augmentation with nitinol endoprosthesis (VNE) to treat painful vertebral compression fractures.MethodsForty patients with one or more painful osteoporotic VCF, confirmed by MRI and accompanied by back-pain unresponsive to a minimum 2 months of conservative medical treatment, underwent VNE at 42 levels. Preoperative and postoperative pain measured with Visual Analog Scale (VAS), disability measured by Oswestry Disability Index (ODI), and vertebral height restoration (measured with 2-dimensional reconstruction CT) were compared at last follow-up (average follow-up 15 months). Cement extravasation, subsequent fractures, and implant migration were recorded.ResultsLong-term follow-up was obtained in 38 of 40 patients. Both VAS and ODI significantly improved from a median of 8.0 (range 5–10) and 66 % (range 44–88 %) to 0.5 (range 0–8) and 6 % (range 6–66 %), respectively, at 1 year (p < 0.0001). Vertebral height measurements comparing time points increased in a statistically significant manner (ANOVA, p < 0.001). Overall cement extravasation rate was 9.5 %. Discal and venous leakage rates were 7.1 and 0 % respectively. No symptomatic extravasations occurred. Five of 38 (13.1 %) patients experienced new spontaneous, osteoporotic fractures. No device change or migration was observed.ConclusionsVNE is a safe and effective procedure that is able to provide long-lasting pain relief and durable vertebral height gain with a low rate of new fractures and cement leakages.

  5. Experience with cinacalcet in primary hyperparathyroidism: results after 1 year of treatment

    PubMed Central

    García-Martín, Antonia; Luque-Pazos, Alessandra

    2013-01-01

    Objectives: To assess the characteristics of patients with primary hyperparathyroidism (PHPT) treated with cinacalcet and to evaluate its efficacy in reducing serum calcium and parathyroid hormone (PTH) concentrations after 1 year of treatment. Methods: The study included 20 patients with PHPT who had completed at least 12 months of treatment with cinacalcet (eight patients for refusal of parathyroidectomy, three for surgery not possible due to comorbidities and nine for progressive hypercalcemia prior to surgery). We recorded clinical and biochemical data at baseline, and after 3, 6 and 12 months of treatment. We also monitored adverse events. Cinacalcet was administered in increasing doses until normal serum calcium was reached or side effects preventing a further increase occurred. Results: After 3 months of treatment, serum calcium significantly decreased (11.73 ± 0.85 versus 10.71 ± 1.63 mg/dl, p < 0.001) and serum phosphorus significantly increased (2.41 ± 0.48 versus 2.63 ± 0.70 mg/dl, p = 0.004) while no significant change occurred in PTH (181.91 ± 102.37 versus 195.47 ± 111.71 pg/ml, p = 0.695). No further variation was observed after 6 months compared with 3 months of follow up. However, after 12 months of treatment, there was a significant decrease in PTH concentrations compared with baseline (181.91 ± 102.37 versus 152.47± 70.16 pg/ml, p = 0.028) as well as serum calcium (11.73 ± 0.85 versus 10.20± 0.95 mg/dl, p < 0.001); serum phosphorus significantly increased (2.41 ± 0.48 versus 2.71 ± 0.43 mg/dl, p = 0.01). Normocalcemia (S-Ca < 10.2 mg/dl) was achieved in 55% of patients. The medication was usually well tolerated (83.4%). Most common adverse events were nausea and vomiting, especially at the beginning of therapy. Conclusion: Cinacalcet rapidly reduced serum calcium in patients with PHPT and this reduction remained stable after 1 year of treatment. We also observed a decrease in PTH. Cinacalcet is an effective alternative in nonsurgical

  6. TRDB—The Tandem Repeats Database

    PubMed Central

    Gelfand, Yevgeniy; Rodriguez, Alfredo; Benson, Gary

    2007-01-01

    Tandem repeats in DNA have been under intensive study for many years, first, as a consequence of their usefulness as genomic markers and DNA fingerprints and more recently as their role in human disease and regulatory processes has become apparent. The Tandem Repeats Database (TRDB) is a public repository of information on tandem repeats in genomic DNA. It contains a variety of tools for repeat analysis, including the Tandem Repeats Finder program, query and filtering capabilities, repeat clustering, polymorphism prediction, PCR primer selection, data visualization and data download in a variety of formats. In addition, TRDB serves as a centralized research workbench. It provides user storage space and permits collaborators to privately share their data and analysis. TRDB is available at . PMID:17175540

  7. Cine-MRI versus two-dimensional echocardiography to measure in vivo left ventricular function in rat heart.

    PubMed

    Stuckey, Daniel J; Carr, Carolyn A; Tyler, Damian J; Clarke, Kieran

    2008-08-01

    Two-dimensional echocardiography is the most commonly used non-invasive method for measuring in vivo cardiac function in experimental animals. In humans, measurements of cardiac function made using cine-MRI compare favourably with those made using echocardiography. However, no rigorous comparison has been made in small animals. Here, standard short-axis two-dimensional (2D) echocardiography (2D-echo) and cine-MRI measurements were made in the same rats, both control and after chronic myocardial infarction. Correlations between the two techniques were found for end diastolic area, stroke area and ejection fraction, but cine-MRI measurements of ejection fraction were 12+/-6% higher than those made using 2D-echo, because of the 1.8-fold higher temporal resolution of the MRI technique (4.6 ms vs 8.3 ms). Repeated measurements on the same group of rats over several days showed that the cine-MRI technique was more reproducible than 2D-echo, in that 2D-echo would require five times more animals to find a statistically significant difference. In summary, caution should be exercised when comparing functional results acquired using short-axis 2D-echo vs cine-MRI. The accuracy of cine-MRI allows identification of alterations in heart function that may be missed when using 2D-echo.

  8. The Incremental Value of Contrast-Enhanced MRI in the Detection of Biopsy-Proven Local Recurrence of Prostate Cancer After Radical Prostatectomy: Effect of Reader Experience

    PubMed Central

    Wassberg, Cecilia; Akin, Oguz; Vargas, Hebert Alberto; Shukla-Dave, Amita; Zhang, Jingbo; Hricak, Hedvig

    2012-01-01

    OBJECTIVE The purpose of this study is to retrospectively assess the incremental value of contrast-enhanced MRI (CE-MRI) to T2-weighted MRI in the detection of postsurgical local recurrence of prostate cancer by readers of different experience levels, using biopsy as the reference standard. MATERIALS AND METHODS Fifty-two men with biochemical recurrence after prostatectomy underwent 1.5-T endorectal MRI with multiphase contrast-enhanced imaging and had biopsy within 3 months of MRI. Two radiologists (reader 1 had 1 year and reader 2 had 6 years of experience) independently reviewed each MRI study and classified the likelihood of recurrent cancer on a 5-point scale. Areas under receiver operating characteristic curves (Az) were calculated to assess readers’ diagnostic performance with T2-weighted MRI alone and combined with CE-MRI. Interobserver agreement was assessed using Cohen kappa statistics. RESULTS Thirty-three patients (63%) had biopsy-proven local recurrence of prostate cancer. With the addition of CE-MRI to T2-weighted imaging, the Az for cancer detection increased significantly for reader 1 (0.77 vs 0.85; p = 0.0435) but not for reader 2 (0.86 vs 0.88; p = 0.7294). The use of CE-MRI improved interobserver agreement from fair (κ = 0.39) to moderate (κ = 0.58). CONCLUSION CE-MRI increased interobserver agreement and offered incremental value to T2-weighted MRI in the detection of locally recurrent prostate cancer for the relatively inexperienced reader. PMID:22826397

  9. Feature extraction for MRI segmentation.

    PubMed

    Velthuizen, R P; Hall, L O; Clarke, L P

    1999-04-01

    Magnetic resonance images (MRIs) of the brain are segmented to measure the efficacy of treatment strategies for brain tumors. To date, no reproducible technique for measuring tumor size is available to the clinician, which hampers progress of the search for good treatment protocols. Many segmentation techniques have been proposed, but the representation (features) of the MRI data has received little attention. A genetic algorithm (GA) search was used to discover a feature set from multi-spectral MRI data. Segmentations were performed using the fuzzy c-means (FCM) clustering technique. Seventeen MRI data sets from five patients were evaluated. The GA feature set produces a more accurate segmentation. The GA fitness function that achieves the best results is the Wilks's lambda statistic when applied to FCM clusters. Compared to linear discriminant analysis, which requires class labels, the same or better accuracy is obtained by the features constructed from a GA search without class labels, allowing fully operator independent segmentation. The GA approach therefore provides a better starting point for the measurement of the response of a brain tumor to treatment.

  10. Visual Scan Adaptation During Repeated Visual Search

    DTIC Science & Technology

    2010-01-01

    repeated distractor –target configurations both require environmental stability. For stable distractor – target configurations, Chun and Jiang (1998) have...demon- strated search time savings from repeating distractor –target configurations, and Song and Jiang (2005) demonstrated that as little as 25% of the...search environment (i.e., two distractor locations and the target location out of 12 total locations per trial) repeated from trial to trial resulted

  11. Short Tandem Repeat DNA Internet Database

    National Institute of Standards and Technology Data Gateway

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  12. MRI Biomarkers in Oncology Clinical Trials

    PubMed Central

    Abramson, Richard G.; Arlinghaus, Lori; Dula, Adrienne; Quarles, C. Chad; Stokes, Ashley; Weis, Jared; Whisenant, Jennifer; Chekmenev, Eduard Y.; Zhukov, Igor; Williams, Jason; Yankeelov, Thomas

    2015-01-01

    Quantitative magnetic resonance imaging (MRI) techniques have the ability to quantitatively report various pathophysiological processes associated with cancer. These measures have been shown to provide complementary information to that typically obtained from standard morphologically based criteria (e.g., size) and, furthermore, have been shown to outperform sized based measures in certain applications. In this review, we discuss eight areas of quantitative MRI that are either currently employed in clinical trials, or are emerging as promising techniques for both diagnosing cancer as well as assessing—or even predicting—the response of cancer to various therapies. The currently employed methods include the response evaluation criteria in solid tumors (RECIST), dynamic susceptibility MRI (DSC-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted imaging (DWI). The emerging techniques covered are chemical exchange saturation transfer MRI (CEST-MRI), elastography, hyperpolarized MRI, and multi-parameter MRI. After a brief introduction to each technique, we present a small number of illustrative applications before noting the existing limitations of each method and what must be done to move each to more routine clinical application. PMID:26613873

  13. Hippocampal Neuron Number Is Unchanged 1 Year After Fractionated Whole-Brain Irradiation at Middle Age

    SciTech Connect

    Shi Lei Molina, Doris P.; Robbins, Michael E.; Wheeler, Kenneth T.; Brunso-Bechtold, Judy K.

    2008-06-01

    Purpose: To determine whether hippocampal neurons are lost 12 months after middle-aged rats received a fractionated course of whole-brain irradiation (WBI) that is expected to be biologically equivalent to the regimens used clinically in the treatment of brain tumors. Methods and Materials: Twelve-month-old Fischer 344 X Brown Norway male rats were divided into WBI and control (CON) groups (n = 6 per group). Anesthetized WBI rats received 45 Gy of {sup 137}Cs {gamma} rays delivered as 9 5-Gy fractions twice per week for 4.5 weeks. Control rats were anesthetized but not irradiated. Twelve months after WBI completion, all rats were anesthetized and perfused with paraformaldehyde, and hippocampal sections were immunostained with the neuron-specific antibody NeuN. Using unbiased stereology, total neuron number and the volume of the neuronal and neuropil layers were determined in the dentate gyrus, CA3, and CA1 subregions of hippocampus. Results: No differences in tissue integrity or neuron distribution were observed between the WBI and CON groups. Moreover, quantitative analysis demonstrated that neither total neuron number nor the volume of neuronal or neuropil layers differed between the two groups for any subregion. Conclusions: Impairment on a hippocampal-dependent learning and memory test occurs 1 year after fractionated WBI at middle age. The same WBI regimen, however, does not lead to a loss of neurons or a reduction in the volume of hippocampus.

  14. Hydrocephalus in children less than 1 year of age in northern Mozambique

    PubMed Central

    Salvador, Sérgio F.; Henriques, João Carlos; Munguambe, Missael; Vaz, Rui M. C.; Barros, Henrique P.

    2014-01-01

    Background: In developed countries, the incidence of neonatal hydrocephalus ranges from 3 to 5 cases per 1000 live births, but little is known about the frequency of hydrocephalus in Africa. In Mozambique, there is no primary information related to this disorder, but using the above data, the expected incidence of neonatal hydrocephalus would range from 2900 to 4800 cases per year. Methods: This study is based on 122 children younger than 1 year with neonatal hydrocephalus, followed up between January 2010 and December 2012, their origin and treatment, and aims to evaluate difficulties with diagnosis, treatment, and follow-up in northern Mozambique. Results: Identified cases were mainly less than 6 months old (77%), with severe macrocephaly and the classic stigmata of this condition. A high rate of follow-up loss (44.3%) was detected, particularly among children from more distant locations. Our findings contrast with the expected 1000-1700 cases that would occur in the area during the study period, being considerably lower. Conclusions: Hydrocephalus is a serious problem in sub-Saharan Africa, whose effects can be minimized by a better organization of the health system in hydrocephalus prevention, referral, and follow-up. New management alternatives to provide treatment to more children with this disorder and reduction of the follow-up difficulties caused due to geographical reasons for the children undergoing treatment are essential. PMID:25593759

  15. The first simultaneous kidney-adrenal gland-pancreas transplantation: outcome at 1 year.

    PubMed

    Vouillarmet, J; Buron, F; Houzard, C; Carlier, M C; Chauvet, C; Brunet, M; Thivolet, C; Morelon, E; Badet, L

    2013-07-01

    Adrenal insufficiency is a rare but life-threatening disease. Replacement therapy sometimes fails to prevent an acute adrenal crisis and most often does not lead to restoration of well-being. We report here the 1-year outcome of the first simultaneous kidney-adrenal gland-pancreas transplantation in a 33-year-old patient with type 1 diabetes and concomitant autoimmune adrenal insufficiency. En bloc left adrenal gland and kidney grafts were anastomosed on the left iliac vessels in normal vascular conditions and the pancreas graft was anastomosed on the right iliac vessels. The immunosuppressive regimen was not modified by the addition of the adrenal gland. We observed no additional morbidity due to the adrenal gland transplantation, as there were no surgical complications. One-year kidney and pancreas graft functions were satisfactory (estimated glomerular filtration rate: 55 mL/min/1.73 m(2) and HbA1c: 4.8%). The adrenal graft functioned well at 12 months with a normalization of cortisol and aldosterone baseline levels. Functional imaging at 3 months showed good uptake of [(123) I]-metaiodobenzylguanidine by the adrenal graft. Transplantation of the adrenal gland en bloc with the left kidney appears to be a good therapeutic option in patients with adrenal insufficiency awaiting kidney or kidney-pancreas transplantation.

  16. Neurophysiological findings in patients 1 year after snake bite induced neurotoxicity in Sri Lanka.

    PubMed

    Bell, D J; Wijegunasinghe, D; Samarakoon, S; Palipana, H; Gunasekera, S; de Silva, H A; Lalloo, D G; Ranawaka, U K; de Silva, H J

    2010-05-01

    Snake bite causes significant morbidity and mortality in Sri Lanka. Snake venoms contain neurotoxins that block neuromuscular junction transmission. Presynaptic neurotoxicity most commonly causes destruction of nerve terminals with recovery by regrowth, whilst postsynaptic neurotoxicity usually involves competition at the acetylcholine receptor. The aim of this study was to investigate whether there were long-term clinical or neurophysiological changes in snake bite survivors 1 year after their envenoming. Detailed neurophysiological tests and clinical examinations were performed on 26 snake bite victims who had presented with neurotoxicity 12 months previously, and their results were compared with controls recruited from the same communities. Significant differences were observed in some nerve conduction parameters in some snake bite victims compared with controls, predominantly in those thought to have elapid bites, including prolongation of sensory, motor and F-wave latencies and reduction of conduction velocities. There was no evidence of any residual deficits in neuromuscular junction transmission. These results suggest a possible demyelinating type polyneuropathy. None of the cases or controls had abnormalities on clinical examination. This is one of the few studies to report possible long-term neurological damage following systemic neurotoxicity after snake bite. The clinical significance of these neurophysiological abnormalities is uncertain and further studies are required to investigate whether the abnormalities persist and to see whether clinical consequences develop.

  17. Global distribution of deep convection reaching tropopause in 1 year GPM observations

    NASA Astrophysics Data System (ADS)

    Liu, Nana; Liu, Chuntao

    2016-04-01

    To characterize and quantify tropopause-reaching deep convection, 1 year of Global Precipitation Mission (GPM) Ku band radar echoes are surveyed in relation to several reference levels derived from the ERA-Interim reanalysis data set. Consistent with the observations of the Tropical Rainfall Measuring Mission over the tropics, the GPM has detected tropopause-reaching deep convection dominantly over tropical land, especially over Panama and Central Africa. At middle and high latitudes, tropopause-reaching convective storms are mainly found over land in the Northern Hemisphere during the summer. Compared to those in the tropics, convective cores at middle and high latitudes have relatively larger sizes at the tropopause, especially those over central North America. The zonal distributions of the occurrences of 15 dBZ and 20 dBZ radar echoes at the tropopause show two comparable maxima, one in the tropics and the other in northern middle-high latitudes. This implies that the convection penetrating the tropopause at northern middle-high latitudes is as frequent as those over the tropics. It is important to understand their role in the vertical transport of trace gases between the troposphere and the stratosphere.

  18. Latent transition models to study women's changing of dietary patterns from pregnancy to 1 year postpartum.

    PubMed

    Sotres-Alvarez, Daniela; Herring, Amy H; Siega-Riz, Anna-Maria

    2013-04-15

    Latent class models are useful for classifying subjects by dietary patterns. Our goals were to use latent transition models to identify dietary patterns during pregnancy and postpartum, to estimate the prevalence of these dietary patterns, and to model transition probabilities between dietary patterns as a function of covariates. Women who were enrolled in the Pregnancy, Infection, and Nutrition Study (University of North Carolina, 2000-2005) were followed for 1 year postpartum, and their diets were assessed in the second trimester and at 3 and 12 months postpartum (n = 519, 484, and 374, respectively) by using a food frequency questionnaire. After adjusting for energy intake, parity, smoking status, race, and education, we identified 3 dietary patterns and named them "prudent," "health conscious Western," and "Western." Nulliparas were 2.9 and 2.1 times more likely to be in the "prudent" class than the "health conscious Western" or the "Western" class, respectively. The 3 dietary patterns were very stable, with the "health conscious Western" class being the least stable; the probability for staying in the same class was 0.74 and 0.87 at 3 and 12 months postpartum, respectively. Breastfeeding mothers were more likely than nonbreastfeeding mothers to switch dietary pattern class (P = 0.0286). Except for breastfeeding mothers, most women did not switch dietary patterns from pregnancy to postpartum.

  19. Attenuated hypothalamic-pituitary-adrenal axis functioning predicts accelerated pubertal development in girls 1 year later.

    PubMed

    Saxbe, Darby E; Negriff, Sonya; Susman, Elizabeth J; Trickett, Penelope K

    2015-08-01

    Accelerated pubertal development has been linked to adverse early environments and may heighten subsequent mental and physical health risks. Hypothalamic-pituitary-adrenal axis functioning has been posited as a mechanism whereby stress may affect pubertal development, but the literature lacks prospective tests of this mechanism. The current study assessed 277 youth (M = 10.84 years, SD = 1.14), 138 boys and 139 girls, who reported on their pubertal development and underwent the Trier Social Stress Test for Children at baseline and returned to the laboratory approximately 1 year later (M = 1.12 years, range = 0.59-1.98 years). For girls, lower cortisol area under the curve (with respect to ground) at Time 1 predicted more advanced pubertal development at Time 2, controlling for Time 1 pubertal development. This association persisted after additional covariates including age, body mass index, race, and maltreatment history were introduced, and was driven by adrenal rather than gonadal development. Cortisol was not linked to boys' subsequent pubertal development, and no interaction by gender or by maltreatment appeared. These results suggest that attenuated cortisol, reported in other studies of children exposed to early adversity, may contribute to accelerated pubertal tempo in girls.

  20. Beyond Earth: Weaving Science and Indigenous Culture - A 1-year NSF Planning Grant

    NASA Astrophysics Data System (ADS)

    Young, Timothy; Guy, M.; Baker Big-Back, C.; Froelich, K.

    2011-01-01

    We present results of a 1-year NSF planning grant called Beyond Earth. The project is designed to engage Native American, urban, and rural families in science learning while piloting curriculum development and implementation that incorporates both Native and Western epistemologies. Physical, earth, and space science content is juxtaposed with indigenous culture, stories, language and epistemology in after-school programs and teacher training. Project partners include the Dakota Science Center, Fort Berthold Community College, and Sitting Bull College. The Native American tribes represented in this initiative illustrate partnerships between the Dakota, Lakota, Nakota, Hidatsa, Mandan, and Arikara. Over the past year the primary project deliverables include a culturally responsive curriculum Beyond Earth Moon Module, teacher training workshops, a project website. The curriculum module introduces students to the moon's appearance, phases, and positions in the sky using the Night Sky Planetarium Experience Station to explore core concepts underlying moon phases and eclipses using the interactive Nature Experience Station before engaging in the culminating Mission Challenge in which they apply their knowledge to problem solving situations and projects. The Native Science and Western Science activities developed, planetarium explorations created, and website toolkit utilizations are presented.

  1. Results of 1 year of clinical experience with independent dose calculation software for VMAT fields

    PubMed Central

    Colodro, Juan Fernando Mata; Berna, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

    2014-01-01

    It is widely accepted that a redundant independent dose calculation (RIDC) must be included in any treatment planning verification procedure. Specifically, volumetric modulated arc therapy (VMAT) technique implies a comprehensive quality assurance (QA) program in which RIDC should be included. In this paper, the results obtained in 1 year of clinical experience are presented. Eclipse from Varian is the treatment planning system (TPS), here in use. RIDC were performed with the commercial software; Diamond® (PTW) which is capable of calculating VMAT fields. Once the plan is clinically accepted, it is exported via Digital Imaging and Communications in Medicine (DICOM) to RIDC, together with the body contour, and then a point dose calculation is performed, usually at the isocenter. A total of 459 plans were evaluated. The total average deviation was -0.3 ± 1.8% (one standard deviation (1SD)). For higher clearance the plans were grouped by location in: Prostate, pelvis, abdomen, chest, head and neck, brain, stereotactic radiosurgery, lung stereotactic body radiation therapy, and miscellaneous. The highest absolute deviation was -0.8 ± 1.5% corresponding to the prostate. A linear fit between doses calculated by RIDC and by TPS produced a correlation coefficient of 0.9991 and a slope of 1.0023. These results are very close to those obtained in the validation process. This agreement led us to consider this RIDC software as a valuable tool for QA in VMAT plans. PMID:25525309

  2. Results of 1 year of clinical experience with independent dose calculation software for VMAT fields.

    PubMed

    Colodro, Juan Fernando Mata; Berna, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

    2014-10-01

    It is widely accepted that a redundant independent dose calculation (RIDC) must be included in any treatment planning verification procedure. Specifically, volumetric modulated arc therapy (VMAT) technique implies a comprehensive quality assurance (QA) program in which RIDC should be included. In this paper, the results obtained in 1 year of clinical experience are presented. Eclipse from Varian is the treatment planning system (TPS), here in use. RIDC were performed with the commercial software; Diamond(®) (PTW) which is capable of calculating VMAT fields. Once the plan is clinically accepted, it is exported via Digital Imaging and Communications in Medicine (DICOM) to RIDC, together with the body contour, and then a point dose calculation is performed, usually at the isocenter. A total of 459 plans were evaluated. The total average deviation was -0.3 ± 1.8% (one standard deviation (1SD)). For higher clearance the plans were grouped by location in: Prostate, pelvis, abdomen, chest, head and neck, brain, stereotactic radiosurgery, lung stereotactic body radiation therapy, and miscellaneous. The highest absolute deviation was -0.8 ± 1.5% corresponding to the prostate. A linear fit between doses calculated by RIDC and by TPS produced a correlation coefficient of 0.9991 and a slope of 1.0023. These results are very close to those obtained in the validation process. This agreement led us to consider this RIDC software as a valuable tool for QA in VMAT plans.

  3. Efficacy and safety of tiotropium Respimat SMI in COPD in two 1-year randomized studies.

    PubMed

    Bateman, Eric; Singh, Dave; Smith, David; Disse, Bernd; Towse, Lesley; Massey, Dan; Blatchford, Jon; Pavia, Demetri; Hodder, Rick

    2010-08-09

    Two 1-year studies evaluated the long-term efficacy and safety of tiotropium 5 or 10 microg versus placebo, inhaled via the Respimat Soft Mist Inhaler (SMI). The two studies were combined and had 4 co-primary endpoints (trough FEV(1) response, Mahler Transition Dyspnea Index [TDI] and St George's Respiratory Questionnaire scores all at week 48, and COPD exacerbations per patient-year). A total of 1990 patients with COPD participated (mean FEV(1): 1.09 L). The mean trough FEV(1) response of tiotropium 5 or 10 microg relative to placebo was 127 or 150 mL, respectively (both P < 0.0001). The COPD exacerbation rate was significantly lower with tiotropium 5 microg (RR = 0.78; P = 0.002) and tiotropium 10 microg (RR = 0.73; P = 0.0008); the health-related quality of life and Mahler TDI co-primary endpoints were significantly improved with both doses (both P < 0.0001). Adverse events were generally balanced except anticholinergic class effects, which were more frequent with active treatment. Fatal events occurred in 2.4% (5 microg), 2.7% (10 microg), and 1.6% (placebo) of patients; these differences were not significant. Tiotropium Respimat SMI 5 microg demonstrated sustained improvements in patients with COPD relative to placebo and similar to the 10 microg dose but with a lower frequency of anticholinergic adverse events.

  4. Recovery of aphasia after stroke: a 1-year follow-up study.

    PubMed

    El Hachioui, Hanane; Lingsma, Hester F; van de Sandt-Koenderman, Mieke E; Dippel, Diederik W J; Koudstaal, Peter J; Visch-Brink, Evy G

    2013-01-01

    Semantics, phonology, and syntax are essential elements of aphasia diagnosis and treatment. Until now, these linguistic components have not been specifically addressed in follow-up studies of aphasia recovery after stroke. The aim of this observational prospective follow-up study was to investigate semantic, phonological, and syntactic recovery in aphasic stroke patients. In addition, we investigated the recovery of verbal communication and of aphasia severity. We assessed 147 aphasic patients at 1, 2, and 6 weeks, 3 and 6 months, and 1 year after stroke with the ScreeLing, a screening test for detecting deficits on the three main linguistic components, the aphasia severity rating scale (ASRS), a measure of verbal communication, and the Token test, a measure of aphasia severity. We investigated the differences in scores between the six time points with mixed models. Semantics and syntax improved up to 6 weeks (p < 0.001) after stroke, and phonology up to 3 months (p ≤ 0.001). ASRS improved up to 6 months (p < 0.05) and the Token test up to 3 months (p < 0.001). We conclude that in aphasia after stroke, various linguistic components have a different recovery pattern, with phonology showing the longest period of recovery that paralleled aphasia severity, as measured with the Token test. The improvement of verbal communication continues after the stabilization of the recovery of the linguistic components.

  5. Ablation for atrial fibrillation during mitral valve surgery: 1-year results through continuous subcutaneous monitoring.

    PubMed

    Bogachev-Prokophiev, Alexandr; Zheleznev, Sergey; Romanov, Alexander; Pokushalov, Evgeny; Pivkin, Alexey; Corbucci, Giorgio; Karaskov, Alexander

    2012-07-01

    Continuous monitoring of cardiac rhythm may play an important role in measuring the true symptomatic/asymptomatic atrial fibrillation (AF) burden and improve the management of anti-arrhythmic and anti-thrombotic therapies. Forty-seven patients with mitral valve disease and longstanding persistent AF (LSPAF) underwent a left atrial maze procedure with bipolar radiofrequency and valve surgery. The follow-up data recorded by an implanted loop recorder were analysed after 3, 6 and 12 months. On discharge, 40 (85.1%) patients were in stable sinus rhythm, as documented by in-office electrocardiography (ECG), 4 (8.5%) were in pacemaker rhythm and 3 (6.4%) were in AF. One (2.1%) patient died after 7 months. On 12-month follow-up examination, 30 (65.2%) patients had an AF burden <0.5% and were classified as responders. Three (6.5%) of the 16 non-responders had atrial flutter and 13 (27.7%) had documented AF recurrences with an AF burden >0.5%. Two (4.3%) patients with AF recurrences were completely asymptomatic. Among the symptomatic events stored by the patients, only 27.6% was confirmed as genuine AF recurrences according to the concomitant ECG recorded by the implanted loop recorder. A concomitant bipolar maze procedure during mitral valve surgery is effective in treating AF, as proved by detailed 1-year continuous monitoring.

  6. Ablation for atrial fibrillation during mitral valve surgery: 1-year results through continuous subcutaneous monitoring†

    PubMed Central

    Bogachev-Prokophiev, Alexandr; Zheleznev, Sergey; Romanov, Alexander; Pokushalov, Evgeny; Pivkin, Alexey; Corbucci, Giorgio; Karaskov, Alexander

    2012-01-01

    Continuous monitoring of cardiac rhythm may play an important role in measuring the true symptomatic/asymptomatic atrial fibrillation (AF) burden and improve the management of anti-arrhythmic and anti-thrombotic therapies. Forty-seven patients with mitral valve disease and longstanding persistent AF (LSPAF) underwent a left atrial maze procedure with bipolar radiofrequency and valve surgery. The follow-up data recorded by an implanted loop recorder were analysed after 3, 6 and 12 months. On discharge, 40 (85.1%) patients were in stable sinus rhythm, as documented by in-office electrocardiography (ECG), 4 (8.5%) were in pacemaker rhythm and 3 (6.4%) were in AF. One (2.1%) patient died after 7 months. On 12-month follow-up examination, 30 (65.2%) patients had an AF burden <0.5% and were classified as responders. Three (6.5%) of the 16 non-responders had atrial flutter and 13 (27.7%) had documented AF recurrences with an AF burden >0.5%. Two (4.3%) patients with AF recurrences were completely asymptomatic. Among the symptomatic events stored by the patients, only 27.6% was confirmed as genuine AF recurrences according to the concomitant ECG recorded by the implanted loop recorder. A concomitant bipolar maze procedure during mitral valve surgery is effective in treating AF, as proved by detailed 1-year continuous monitoring. PMID:22514258

  7. Lambda Exonuclease Digestion of CGG Trinucleotide Repeats

    PubMed Central

    Conroy, R.S.; Koretsky, A.P.; Moreland, J.

    2011-01-01

    Fragile X syndrome and other triplet repeat diseases are characterized by an elongation of a repeating DNA triplet. The ensemble-averaged lambda exonuclease digestion rate of different substrates, including one with an elongated FMR1 gene containing 120 CGG repeats, was measured using absorption and fluorescence spectroscopy. Using magnetic tweezers sequence-dependent digestion rates and pausing was measured for individual lambda exonucleases. Within the triplet repeats a lower average and narrower distribution of rates and a higher frequency of pausing was observed. PMID:19562332

  8. Characteristic MRI Findings of upper Limb Muscle Involvement in Myotonic Dystrophy Type 1.

    PubMed

    Sugie, Kazuma; Sugie, Miho; Taoka, Toshio; Tonomura, Yasuyo; Kumazawa, Aya; Izumi, Tesseki; Kichikawa, Kimihiko; Ueno, Satoshi

    2015-01-01

    The objective of our study was to evaluate the relation between muscle MRI findings and upper limb weakness with grip myotonia in patients with myotonic dystrophy type 1 (DM1). Seventeen patients with DM1 were evaluated by manual muscle strength testing and muscle MRI of the upper limbs. Many DM1 patients presenting with decreased grasping power frequently showed high intensity signals in the flexor digitorum profundus (FDP) muscles on T1-weighted imaging. Patients presenting with upper limb weakness frequently also showed high intensity signals in the flexor pollicis longus, abductor pollicis longus, and extensor pollicis muscles. Disturbances of the distal muscles of the upper limbs were predominant in all DM1 patients. Some DM1 patients with a prolonged disease duration showed involvement of not only distal muscles but also proximal muscles in the upper limbs. Muscle involvement of the upper limbs on MRI strongly correlated positively with the disease duration or the numbers of CTG repeats. To our knowledge, this is the first study to provide a detailed description of the distribution and severity of affected muscles of the upper limbs on MRI in patients with DM1. We conclude that muscle MRI findings are very useful for identifying affected muscles and predicting the risk of muscle weakness in the upper limbs of DM1 patients.

  9. Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

    PubMed Central

    Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

    2010-01-01

    Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

  10. Response to immunotherapy in CLIPPERS: clinical, MRI, and MRS follow-up.

    PubMed

    Sempere, Angel P; Mola, Santiago; Martin-Medina, Patricia; Bernabeu, Angela; Khabbaz, Elias; Lopez-Celada, Susana

    2013-04-01

    Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently defined inflammatory central nervous system disorder responsive to steroids with characteristic magnetic resonance imaging (MRI) features. We report a 69-year-old man presenting with gait ataxia with the characteristic MRI features of CLIPPERS and describe the clinical, MRI, and magnetic resonance spectroscopy (MRS) follow-up after treatment with glucocorticosteroids. Brain and spine MRI showed punctate enhancement peppering the brainstem, cerebellar peduncles, and upper cervical cord. In MRS, the ratio of N-acetyl aspartate to creatine (NAA/Cr) was significantly decreased in the pons and both thalami. An extensive evaluation found no alternative diagnoses. Treatment with steroids led to rapid clinical improvement. Repeat MRI and MRS showed complete resolution of gadolinium-enhancing lesions and recovery of NAA/Cr levels in the pons and thalami. After 1 month of tapering oral steroids, weekly oral methotrexate was started and the patient has remained stable for the past 6 months.

  11. Physiological characterization of a robust survival rodent fMRI method.

    PubMed

    Brynildsen, Julia K; Hsu, Li-Ming; Ross, Thomas J; Stein, Elliot A; Yang, Yihong; Lu, Hanbing

    2017-01-01

    Anesthetics are commonly used in preclinical functional MRI studies. It is well-appreciated that proper choice of anesthetics is of critical importance for maintaining a physiologically normal range of autonomic functioning. A recent study, using a low dose of dexmedetomidine (active isomer of medetomidine) in combination with a low dose of isoflurane, suggested stable measurements across repeated fMRI experiments in individual animals with each session lasting up to several hours. The rat default mode network has been successfully identified using this preparation, indicating that this protocol minimally disturbs brain network functions. However, medetomidine is known to cause peripheral vasoconstriction, respiratory suppression, and bradycardia, each of which could independently confound the BOLD signal. The goal of this study was to systematically characterize physiological conditions for fMRI experiments under this anesthetic regimen. To this end, we acquired somatosensory stimulation "task-evoked" and resting-state fMRI to evaluate the integrity of neurovascular coupling and brain network function during three time windows (0-30min, 30-90min, and 90-150min) following dexmedetomidine initiation. Results demonstrate that both evoked BOLD response and resting-state fMRI signal remained stable during the 90-150min time window, while autonomic physiological parameters maintained near-normal conditions during this period. Our data suggest that using a spontaneously-inhaled, low dose of isoflurane in combination with a continuous low dose of dexmedetomidine is a viable option for longitudinal imaging studies in rats.

  12. A novel diffusion-tensor MRI approach for skeletal muscle fascicle length measurements.

    PubMed

    Oudeman, Jos; Mazzoli, Valentina; Marra, Marco A; Nicolay, Klaas; Maas, Mario; Verdonschot, Nico; Sprengers, Andre M; Nederveen, Aart J; Strijkers, Gustav J; Froeling, Martijn

    2016-12-01

    Musculoskeletal (dys-)function relies for a large part on muscle architecture which can be obtained using Diffusion-Tensor MRI (DT-MRI) and fiber tractography. However, reconstructed tracts often continue along the tendon or aponeurosis when using conventional methods, thus overestimating fascicle lengths. In this study, we propose a new method for semiautomatic segmentation of tendinous tissue using tract density (TD). We investigated the feasibility and repeatability of this method to quantify the mean fascicle length per muscle. Additionally, we examined whether the method facilitates measuring changes in fascicle length of lower leg muscles with different foot positions. Five healthy subjects underwent two DT-MRI scans of the right lower leg, with the foot in 15° dorsiflexion, neutral, and 30° plantarflexion positions. Repeatability of fascicle length measurements was assessed using Bland-Altman analysis. Changes in fascicle lengths between the foot positions were tested using a repeated multivariate analysis of variance (MANOVA). Bland-Altman analysis showed good agreement between repeated measurements. The coefficients of variation in neutral position were 8.3, 16.7, 11.2, and 10.4% for soleus (SOL), fibularis longus (FL), extensor digitorum longus (EDL), and tibialis anterior (TA), respectively. The plantarflexors (SOL and FL) showed significant increase in fascicle length from plantarflexion to dorsiflexion, whereas the dorsiflexors (EDL and TA) exhibited a significant decrease. The use of a tract density for semiautomatic segmentation of tendinous structures provides more accurate estimates of the mean fascicle length than traditional fiber tractography methods. The method shows moderate to good repeatability and allows for quantification of changes in fascicle lengths due to passive stretch.

  13. Radio-frequency ablation of small renal tumors: minimum follow up of 1 year

    NASA Astrophysics Data System (ADS)

    Patel, Vipul; Thaly, Rahul; Shah, Ketul

    2007-02-01

    OBJECTIVE: With the increased utility of complex imaging modalities small renal tumors are being diagnosed with rising frequency. We performed radiofrequency ablation to treat tumors less than 4cm in size using a combination of temperature, impedance, ultrasound and laparoscopic guidance. In this article we reviewed the outcome of radiofrequency ablation of renal tumors at one year at our institution. MATERIALS AND METHODS: Over a three-year period 75 patients with a total of 93 renal tumors underwent radiofrequency ablation. Average patient age was 64.5 years with ASA of 2.9. Indications for nephron sparing were imperative in 33 (solitary kidney 21, renal insufficiency 12). Seventeen patients had significant co-morbidities with ASA score of 3 or more and were thought to be poor candidates for nephrectomy or partial nephrectomy. Five were Jehovah's Witness patients. Average tumor size was 3.2 cm (1.5-4.0). 60% of the tumors were exophytic and 40% deep. Radiofrequency ablation was performed via a transperitoneal approach using the single pronged 3cm Cool tip electrode (Radionics Inc). Tumor was isolated laparoscopically. Prior to ablation the lesions were biopsied. Ablation was performed using both laparoscopic and real-time ultrasound imaging of the boarders of the tumor. During ablation impedance and temperature monitoring was performed. For each tumor two separate ablations were performed at perpendicular angles, the first ablation was for 6 minutes and the second for 3 minutes. The center and periphery of the tumor was monitored to insure that the temperature rose above 70 degrees Celsius. Patients were followed at three-month intervals with triple phase CT scan or MRI to evaluate efficacy of the ablation. Our criteria for recurrent tumor were growth or enhancement of the lesion. RESULTS: Average operative time was 109 minutes with and average EBL of <25cc. Mean hospital stay was 1.4 days. At average follow up of 19.2 months (range 2-24), one lesion showed

  14. Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.

    PubMed

    Mellis, M G; Ingle, L; Carroll, S

    2014-02-01

    This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P < 0.001). Lower coefficient of variation (≤ 10.2%) and narrower limits of agreement were found for actual heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults.

  15. Protection against malaria at 1 year and immune correlates following PfSPZ vaccination.

    PubMed

    Ishizuka, Andrew S; Lyke, Kirsten E; DeZure, Adam; Berry, Andrea A; Richie, Thomas L; Mendoza, Floreliz H; Enama, Mary E; Gordon, Ingelise J; Chang, Lee-Jah; Sarwar, Uzma N; Zephir, Kathryn L; Holman, LaSonji A; James, Eric R; Billingsley, Peter F; Gunasekera, Anusha; Chakravarty, Sumana; Manoj, Anita; Li, MingLin; Ruben, Adam J; Li, Tao; Eappen, Abraham G; Stafford, Richard E; K C, Natasha; Murshedkar, Tooba; DeCederfelt, Hope; Plummer, Sarah H; Hendel, Cynthia S; Novik, Laura; Costner, Pamela J M; Saunders, Jamie G; Laurens, Matthew B; Plowe, Christopher V; Flynn, Barbara; Whalen, William R; Todd, J P; Noor, Jay; Rao, Srinivas; Sierra-Davidson, Kailan; Lynn, Geoffrey M; Epstein, Judith E; Kemp, Margaret A; Fahle, Gary A; Mikolajczak, Sebastian A; Fishbaugher, Matthew; Sack, Brandon K; Kappe, Stefan H I; Davidson, Silas A; Garver, Lindsey S; Björkström, Niklas K; Nason, Martha C; Graham, Barney S; Roederer, Mario; Sim, B Kim Lee; Hoffman, Stephen L; Ledgerwood, Julie E; Seder, Robert A

    2016-06-01

    An attenuated Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine, PfSPZ Vaccine, is highly protective against controlled human malaria infection (CHMI) 3 weeks after immunization, but the durability of protection is unknown. We assessed how vaccine dosage, regimen, and route of administration affected durable protection in malaria-naive adults. After four intravenous immunizations with 2.7 × 10(5) PfSPZ, 6/11 (55%) vaccinated subjects remained without parasitemia following CHMI 21 weeks after immunization. Five non-parasitemic subjects from this dosage group underwent repeat CHMI at 59 weeks, and none developed parasitemia. Although Pf-specific serum antibody levels correlated with protection up to 21-25 weeks after immunization, antibody levels waned substantially by 59 weeks. Pf-specific T cell responses also declined in blood by 59 weeks. To determine whether T cell responses in blood reflected responses in liver, we vaccinated nonhuman primates with PfSPZ Vaccine. Pf-specific interferon-γ-producing CD8 T cells were present at ∼100-fold higher frequencies in liver than in blood. Our findings suggest that PfSPZ Vaccine conferred durable protection to malaria through long-lived tissue-resident T cells and that administration of higher doses may further enhance protection.

  16. Multiparametric Breast MRI of Breast Cancer

    PubMed Central

    Rahbar, Habib; Partridge, Savannah C.

    2015-01-01

    Synopsis Breast MRI has increased in popularity over the past two decades due to evidence for its high sensitivity for cancer detection. Current clinical MRI approaches rely on the use of a dynamic contrast enhanced (DCE-MRI) acquisition that facilitates morphologic and semi-quantitative kinetic assessments of breast lesions. The use of more functional and quantitative parameters, such as pharmacokinetic features from high temporal resolution DCE-MRI, apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) on diffusion weighted MRI, and choline concentrations on MR spectroscopy, hold promise to broaden the utility of MRI and improve its specificity. However, due to wide variations in approach among centers for measuring these parameters and the considerable technical challenges, robust multicenter data supporting their routine use is not yet available, limiting current applications of many of these tools to research purposes. PMID:26613883

  17. Moyamoya disease: diagnostic accuracy of MRI.

    PubMed

    Yamada, I; Suzuki, S; Matsushima, Y

    1995-07-01

    Our purpose was to evaluate the diagnostic accuracy of MRI in moyamoya disease. We studied 30 patients with this disease, comparing MRI and angiographic findings. The diagnostic value of MRI was evaluated for occlusive lesions, collateral vessels, and parenchymal lesions. In all patients bilateral occlusion or stenosis of the supraclinoid internal carotid artery and proximal anterior and middle cerebral arteries was clearly shown by MRI, and staging of the extent of occlusion agreed with angiographic staging in 44 (73%) of 60 arteries. MRI, particularly coronal images, clearly showed basal cerebral moyamoya vessels in 54 hemispheres, and 45 of a total of 71 large leptomeningeal and transdural collateral vessels were identified. MRI also showed parenchymal lesions in 48 (80%) hemispheres, and the extent of occlusion in the anterior and posterior circulations respectively correlated with white matter and cortical and/or subcortical infarcts.

  18. Brain development in preterm infants assessed using advanced MRI techniques.

    PubMed

    Tusor, Nora; Arichi, Tomoki; Counsell, Serena J; Edwards, A David

    2014-03-01

    Infants who are born preterm have a high incidence of neurocognitive and neurobehavioral abnormalities, which may be associated with impaired brain development. Advanced magnetic resonance imaging (MRI) approaches, such as diffusion MRI (d-MRI) and functional MRI (fMRI), provide objective and reproducible measures of brain development. Indices derived from d-MRI can be used to provide quantitative measures of preterm brain injury. Although fMRI of the neonatal brain is currently a research tool, future studies combining d-MRI and fMRI have the potential to assess the structural and functional properties of the developing brain and its response to injury.

  19. A novel anthropomorphic flow phantom for the quantitative evaluation of prostate DCE-MRI acquisition techniques

    NASA Astrophysics Data System (ADS)

    Knight, Silvin P.; Browne, Jacinta E.; Meaney, James F.; Smith, David S.; Fagan, Andrew J.

    2016-10-01

    A novel anthropomorphic flow phantom device has been developed, which can be used for quantitatively assessing the ability of magnetic resonance imaging (MRI) scanners to accurately measure signal/concentration time-intensity curves (CTCs) associated with dynamic contrast-enhanced (DCE) MRI. Modelling of the complex pharmacokinetics of contrast agents as they perfuse through the tumour capillary network has shown great promise for cancer diagnosis and therapy monitoring. However, clinical adoption has been hindered by methodological problems, resulting in a lack of consensus regarding the most appropriate acquisition and modelling methodology to use and a consequent wide discrepancy in published data. A heretofore overlooked source of such discrepancy may arise from measurement errors of tumour CTCs deriving from the imaging pulse sequence itself, while the effects on the fidelity of CTC measurement of using rapidly-accelerated sequences such as parallel imaging and compressed sensing remain unknown. The present work aimed to investigate these features by developing a test device in which ‘ground truth’ CTCs were generated and presented to the MRI scanner for measurement, thereby allowing for an assessment of the DCE-MRI protocol to accurately measure this curve shape. The device comprised a four-pump flow system wherein CTCs derived from prior patient prostate data were produced in measurement chambers placed within the imaged volume. The ground truth was determined as the mean of repeat measurements using an MRI-independent, custom-built optical imaging system. In DCE-MRI experiments, significant discrepancies between the ground truth and measured CTCs were found for both tumorous and healthy tissue-mimicking curve shapes. Pharmacokinetic modelling revealed errors in measured K trans, v e and k ep values of up to 42%, 31%, and 50% respectively, following a simple variation of the parallel imaging factor and number of signal averages in the acquisition

  20. Test-retest reliability of white matter structural brain networks: a multiband diffusion MRI study.

    PubMed

    Zhao, Tengda; Duan, Fei; Liao, Xuhong; Dai, Zhengjia; Cao, Miao; He, Yong; Shu, Ni

    2015-01-01

    The multiband EPI sequence has been developed for the human connectome project to accelerate MRI data acquisition. However, no study has yet investigated the test-retest (TRT) reliability of the graph metrics of white matter (WM) structural brain networks constructed from this new sequence. Here, we employed a multiband diffusion MRI (dMRI) dataset with repeated scanning sessions and constructed both low- and high-resolution WM networks by volume- and surface-based parcellation methods. The reproducibility of network metrics and its dependence on type of construction procedures was assessed by the intra-class correlation coefficient (ICC). We observed conserved topological architecture of WM structural networks constructed from the multiband dMRI data as previous findings from conventional dMRI. For the global network properties, the first order metrics were more reliable than second order metrics. Between two parcellation methods, networks with volume-based parcellation showed better reliability than surface-based parcellation, especially for the global metrics. Between different resolutions, the high-resolution network exhibited higher TRT performance than the low-resolution in terms of the global metrics with a large effect size, whereas the low-resolution performs better in terms of local (region and connection) properties with a relatively low effect size. Moreover, we identified that the association and primary cortices showed higher reproducibility than the paralimbic/limbic regions. The important hub regions and rich-club connections are more reliable than the non-hub regions and connections. Finally, we found WM networks from the multiband dMRI showed higher reproducibility compared with those from the conventional dMRI. Together, our results demonstrated the fair to good reliability of the WM structural brain networks from the multiband EPI sequence, suggesting its potential utility for exploring individual differences and for clinical applications.

  1. Semisupervised segmentation of MRI stroke studies

    NASA Astrophysics Data System (ADS)

    Soltanian-Zadeh, Hamid; Windham, Joe P.; Robbins, Linda

    1997-04-01

    Fast, accurate, and reproducible image segmentation is vital to the diagnosis, treatment, and evaluation of many medical situations. We present development and application of a semi-supervised method for segmenting normal and abnormal brain tissues from magnetic resonance images (MRI) of stroke patients. The method does not require manual drawing of the tissue boundaries. It is therefore faster and more reproducible than conventional methods. The steps of the new method are as follows: (1) T2- and T1-weighted MR images are co-registered using a head and hat approach. (2) Intracranial brain volume is segmented from the skull, scalp, and background using a multi-resolution edge tracking algorithm. (3) Additive noise is suppressed (image is restored) using a non-linear edge-preserving filter which preserves partial volume information on average. (4) Image nonuniformities are corrected using a modified lowpass filtering approach. (5) The resulting images are segmented using a self organizing data analysis technique which is similar in principle to the K-means clustering but includes a set of additional heuristic merging and splitting procedures to generate a meaningful segmentation. (6) Segmented regions are labeled white matter, gray matter, CSF, partial volumes of normal tissues, zones of stroke, or partial volumes between stroke and normal tissues. (7) Previous steps are repeated for each slice of the brain and the volume of each tissue type is estimated from the results. Details and significance of each step are explained. Experimental results using a simulation, a phantom, and selected clinical cases are presented.

  2. All repeats are not equal: a module-based approach to guide repeat protein design.

    PubMed

    Sawyer, Nicholas; Chen, Jieming; Regan, Lynne

    2013-05-27

    Repeat proteins composed of tandem arrays of a short structural motif often mediate protein-protein interactions. Past efforts to design repeat protein-based molecular recognition tools have focused on the creation of templates from the consensus of individual repeats, regardless of their natural context. Such an approach assumes that all repeats are essentially equivalent. In this study, we present the results of a "module-based" approach in which modules composed of tandem repeats are aligned to identify repeat-specific features. Using this approach to analyze tetratricopeptide repeat modules that contain three tandem repeats (3TPRs), we identify two classes of 3TPR modules with distinct structural signatures that are correlated with different sets of functional residues. Our analyses also reveal a high degree of correlation between positions across the entire ligand-binding surface, indicative of a coordinated, coevolving binding surface. Extension of our analyses to different repeat protein modules reveals more examples of repeat-specific features, especially in armadillo repeat modules. In summary, the module-based analyses that we present effectively capture key repeat-specific features that will be important to include in future repeat protein design templates.

  3. Increased Cardiovascular Events and Subclinical Atherosclerosis in Rheumatoid Arthritis Patients: 1 Year Prospective Single Centre Study

    PubMed Central

    Ruscitti, Piero; Cipriani, Paola; Masedu, Francesco; Romano, Silvio; Berardicurti, Onorina; Liakouli, Vasiliki; Carubbi, Francesco; Di Benedetto, Paola; Alvaro, Saverio; Penco, Maria; Valenti, Marco; Giacomelli, Roberto

    2017-01-01

    Objectives Several studies showed the close relationship between Rheumatoid Arthritis (RA) and cerebro-cardiovascular events (CVEs) and subclinical atherosclerosis. In this study, we investigated the occurrence of CVEs and subclinical atherosclerosis during the course of RA and we evaluated the possible role of both traditional cardiovascular (CV) and disease related risk factors to predict the occurrence of new CVEs and the onset of subclinical atherosclerosis. Methods We designed a single centre, bias-adjusted, prospective, observational study to investigate, in a homogeneous subset of RA patients, the occurrence of new onset of CVEs and subclinical atherosclerosis. Statistical analyses were performed to evaluate the role of traditional CV and disease-related risk factors to predict the occurrence of new CVEs and subclinical atherosclerosis. Results We enrolled 347 RA patients prospectively followed for 12 months. An increased percentage of patients experienced CVEs, developed subclinical atherosclerosis and was affected by systemic arterial hypertension (SAH), type 2 diabetes mellitus and metabolic syndrome (MS), at the end of follow up. Our analysis showed that the insurgence of both SAH and MS, during the follow up, the older age, the CVE familiarity and the lack of clinical response, were associated with a significantly increased risk to experience CVEs and to develop subclinical atherosclerosis. Conclusions Our study quantifies the increased expected risk for CVEs in a cohort of RA patients prospectively followed for 1 year. The occurrence of both new CVEs and subclinical atherosclerosis in RA patients may be explained by inflammatory burden as well as traditional CV risk factors. PMID:28103312

  4. Enzyme Replacement Therapy in Mucopolysaccharidosis II Patients Under 1 Year of Age.

    PubMed

    Lampe, Christina; Atherton, Andrea; Burton, Barbara K; Descartes, Maria; Giugliani, Roberto; Horovitz, Dafne D G; Kyosen, Sandra O; Magalhães, Tatiana S P C; Martins, Ana Maria; Mendelsohn, Nancy J; Muenzer, Joseph; Smith, Laurie D

    2014-01-01

    Mucopolysaccharidosis (MPS) II, or Hunter syndrome, is a lysosomal storage disease characterized by multi-systemic involvement and a progressive clinical course. Enzyme replacement therapy with idursulfase has been approved in more than 50 countries worldwide; however, safety and efficacy data from clinical studies are currently only available for patients 1.4 years of age and older. Sibling case studies of infants with MPS I, II, and VI who initiated ERT in the first weeks or months of life have reported no new safety concerns and a more favorable clinical course for the sibling treated in infancy than for the later-treated sibling. Here we describe our experiences with a case series of eight MPS II patients for whom idursulfase treatment was initiated at under 1 year of age. The majority of the patients were diagnosed because of a family history of disease. All of the infants displayed abnormalities consistent with MPS II at diagnosis. The youngest age at treatment start was 10 days and the oldest was 6.5 months, with duration of treatment varying between 6 weeks and 5.5 years. No new safety concerns were observed, and none of the patients experienced an infusion-related reaction. All of the patients treated for more than 6 weeks showed improvements and/or stabilization of some somatic manifestations while on treatment. In some cases, caregivers made comparisons with other affected family members and reported that the early-treated patients experienced a less severe clinical course, although a lack of medical records for many family members precluded a rigorous comparison.

  5. Encouraging responses in sexual and relationship violence prevention: what program effects remain 1 year later?

    PubMed

    Moynihan, Mary M; Banyard, Victoria L; Cares, Alison C; Potter, Sharyn J; Williams, Linda M; Stapleton, Jane G

    2015-01-01

    Colleges and universities are high-risk settings for sexual and relationship violence. To address these problems, institutions of higher education have implemented prevention programs, many of which train students as potential bystanders who can step in to help diffuse risky situations, identify and challenge perpetrators, and assist victims. The impact of bystander sexual and relationship violence prevention programs on long-term behavior of bystanders has remained a key unanswered question for those who seek to offer the most effective programs as well as for policy makers. In this study, the researchers experimentally evaluated the effectiveness of the Bringing in the Bystander® in-person program. Participants were 948 1st-year college students of whom 47.8% were women and 85.2% identified as White (15% also identified as Hispanic in a separate question) between the ages of 18 and 24 at two universities (one a rural, primarily residential campus and the other an urban, highly commuter campus) in the northeastern United States. To date, this is the first study to have found positive behavior changes as long-lasting as 1 year following an educational workshop focusing on engaging bystanders in preventing sexual and relationship violence. Even so, many questions remain to be answered about prevention and intervention of this type. More prospective research is needed on bystander-focused prevention of these forms of violence to help understand and better predict the complicated relationships both between and among the attitudes and behaviors related to preventing sexual and relationship violence. In this regard, we make specific recommendations for designing and evaluating programs based on our findings relating to the importance of moderators, especially two key understudied ones, readiness to help and opportunity to intervene.

  6. Robot-assisted laparoscopic pyeloplasty: minimum 1-year follow-up

    NASA Astrophysics Data System (ADS)

    Patel, Vipul; Thaly, Rahul; Shah, Ketul

    2007-02-01

    Objectives: To evaluate the feasibility and efficacy of robotic-assisted laparoscopic pyeloplasty. Laparoscopic pyeloplasty has been shown to have a success rate comparable to that of the open surgical approach. However, the steep learning curve has hindered its acceptance into mainstream urologic practice. The introduction of robotic assistance provides advantages that have the potential to facilitate precise dissection and intracorporeal suturing. Methods: A total of 50 patients underwent robotic-assisted laparoscopic dismembered pyeloplasty. A four-trocar technique was used. Most patients were discharged home on day 1, with stent removal at 3 weeks. Patency of the ureteropelvic junction was assessed in all patients with mercaptotriglycylglycine Lasix renograms at 1, 3, 6, 9, and 12 months, then every 6 months for 1 year, and then yearly. Results: Each patient underwent a successful procedure without open conversion or transfusion. The average estimated blood loss was 40 ml. The operative time averaged 122 minutes (range 60 to 330) overall. Crossing vessels were present in 30% of the patients and were preserved in all cases. The time for the anastomosis averaged 20 minutes (range 10 to 100). Intraoperatively, no complications occurred. Postoperatively, the average hospital stay was 1.1 days. The stents were removed at an average of 20 days (range 14 to 28) postoperatively. The average follow-up was 11.7 months; at the last follow-up visit, each patient was doing well. Of the 50 patients, 48 underwent one or more renograms, demonstrating stable renal function, improved drainage, and no evidence of recurrent obstruction. Conclusions: Robotic-assisted laparoscopic pyeloplasty is a feasible technique for ureteropelvic junction reconstruction. The procedure provides a minimally invasive alternative with good short-term results.

  7. Aerosol source apportionment from 1-year measurements at the CESAR tower in Cabauw, the Netherlands

    NASA Astrophysics Data System (ADS)

    Schlag, Patrick; Kiendler-Scharr, Astrid; Blom, Marcus Johannes; Canonaco, Francesco; Sebastiaan Henzing, Jeroen; Moerman, Marcel; Prévôt, André Stephan Henry; Holzinger, Rupert

    2016-07-01

    Intensive measurements of submicron aerosol particles and their chemical composition were performed with an Aerosol Chemical Speciation Monitor (ACSM) at the Cabauw Experimental Site for Atmospheric Research (CESAR) in Cabauw, the Netherlands, sampling at 5 m height above ground. The campaign lasted nearly 1 year from July 2012 to June 2013 as part of the EU-FP7-ACTRIS project (Q-ACSM Network). Including equivalent black carbon an average particulate mass concentration of 9.50 µg m-3 was obtained during the whole campaign with dominant contributions from ammonium nitrate (45 %), organic aerosol (OA, 29 %), and ammonium sulfate (19 %). There were 12 exceedances of the World Health Organization (WHO) PM2.5 daily mean limit (25 µg m-3) observed at this rural site using PM1 instrumentation only. Ammonium nitrate and OA represented the largest contributors to total particulate matter during periods of exceedance. Source apportionment of OA was performed season-wise by positive matrix factorization (PMF) using the multilinear engine 2 (ME-2) controlled via the source finder (SoFi). Primary organic aerosols were attributed mainly to traffic (8-16 % contribution to total OA, averaged season-wise) and biomass burning (0-23 %). Secondary organic aerosols (SOAs, 61-84 %) dominated the organic fraction during the whole campaign, particularly on days with high mass loadings. A SOA factor which is attributed to humic-like substances (HULIS) was identified as a highly oxidized background aerosol in Cabauw. This shows the importance of atmospheric aging processes for aerosol concentration at this rural site. Due to the large secondary fraction, the reduction of particulate mass at this rural site is challenging on a local scale.

  8. Effectiveness of a multidisciplinary heart failure disease management programme on 1-year mortality: Prospective cohort study.

    PubMed

    Laborde-Castérot, Hervé; Agrinier, Nelly; Zannad, Faiez; Mebazaa, Alexandre; Rossignol, Patrick; Girerd, Nicolas; Alla, François; Thilly, Nathalie

    2016-09-01

    We performed a multicenter prospective observational cohort study (Epidémiologie et Pronostic de l'Insuffisance Cardiaque Aiguë en Lorraine, Epidemiology and Prognosis of Acute Heart Failure in Lorraine [EPICAL2]) to evaluate the effectiveness on mortality of a community-based multidisciplinary disease management programme (DMP) for heart failure (HF) patients.Between October 2011 and October 2012, 1816 patients, who were hospitalized for acute HF or who developed acute HF during a hospitalization, were included from 21 hospitals in a northeast region of France. At hospital admission, their mean age was 77.3 (standard deviation [SD] 11.6) years and mean left ventricular ejection fraction was 45.0 (SD 16.0)%. A subset of patients were enrolled in a multidimensional DMP for HF (n = 312, 17.2%), based on structured patient education, home monitoring visits by HF-trained nurses, and automatic alerts triggered by significant clinical and biological changes to the patient. The DMP involved general practitioners, nurses, and cardiologists collaborating via an individual web-based medical electronic record. The outcome was all-cause mortality from the 3rd to the 12th month after discharge. During the follow-up, a total of 377 (20.8%) patients died: 321 (21.3%) in the control group and 56 (17.9%) in the DMP group. In a propensity score analysis, DMP was associated with lower 1-year all-cause mortality (hazard ratio 0.65, 95% CI 0.46-0.92). Instrumental variable analysis gave similar results (hazard ratio 0.56, 0.27-1.16).In a real world setting, a multidimensional DMP for HF with structured patient education, home nurse monitoring, and appropriate physician alerts may improve survival when implemented after discharge from hospitalization due to worsening HF.

  9. Selective laser trabeculoplasty (SLT): 1-year results in early and advanced open angle glaucoma.

    PubMed

    Schlote, Torsten; Kynigopoulos, Myron

    2016-02-01

    The purpose of this study was to examine the efficacy of selective laser trabeculoplasty (SLT) in eyes with early and more advanced stages of open angle glaucoma within 1 year of follow-up. Retrospective chart review in a consecutive series of patients treated by SLT to reduce intraocular pressure (IOP) or decrease number of topical medications in cases of discomfort and allergy. The cup-to-disc ratio of the optic nerve and the GSS 2 (glaucoma staging system 2) was used to differentiate between early (group 1) and more advanced (group 2) stages of glaucoma. At the time of SLT treatment, no new signs of glaucoma progression were seen. Only the first treated eye of every patient was included in the analysis. In group 1 (early glaucoma), 27 eyes were included. IOP reduction <21 mmHg/>20 % of the preoperative IOP-value and reduction of medication were achieved in 17 eyes (62.96 %). Successful re-treatment was necessary in 2 eyes (7.4 %). In group 2 (advanced glaucoma), 44 eyes underwent SLT. In eight eyes (18.18 %), filtrating surgery was necessary after initial SLT. In the remaining 36 eyes, IOP reduction <21 mmHg/>20 % of the baseline IOP was achieved in 26 eyes (59.09 % of 44 eyes) and IOP reduction <18 mmHg/> 30 % of the baseline IOP in 22 eyes (50 % of 44 eyes). SLT was safe and effective in nearly 2/3 of early glaucoma patients and also in 50 % of advanced glaucoma patients using stronger criteria of success. Failure of SLT in advanced glaucoma should lead to immediate filtrating surgery, which seems not to be associated with higher risk of fibrosis.

  10. Impact of universal varicella vaccination on 1-year-olds in Uruguay: 1997–2005

    PubMed Central

    Quian, J; Rüttimann, R; Romero, C; Dall’Orso, P; Cerisola, A; Breuer, T; Greenberg, M; Verstraeten, T

    2008-01-01

    Objective: Varicella vaccination was introduced at the end of 1999 into the Uruguayan immunisation schedule for children aged 12 months. Varilrix (Oka strain; GlaxoSmithKline Biologicals) has been the only vaccine used since then and coverage has been estimated to exceed 90% since the start of the universal varicella vaccination programme. We assessed the impact of the Uruguayan varicella vaccination programme during 2005, 6 years after its introduction. Methods: Information on hospitalisations was collected from the main paediatric referral hospital and information on medical consultations for varicella was collected from two private health insurance systems in Montevideo. The proportion of hospitalisations due to varicella and the proportion of ambulatory visits for varicella since the introduction of the vaccine were compared between 1999 and 2005 and 1997 and 1999 in the following age groups: <1 year, 1–4 years, 5–9 years and 10–14 years. Results: By 2005, the proportion of hospitalisations due to varicella among children, was reduced by 81% overall and by 63%, 94%, 73% and 62% in the <1, 1–4, 5–9 and 10–14 years age groups, respectively. The incidence of ambulatory visits for varicella among children was reduced by 87% overall and by 80%, 97%, 81% and 65% in the <1, 1–4, 5–9 and 10–14 years age groups, respectively. Conclusions: The burden of varicella has decreased substantially in Uruguayan children since the introduction of the varicella vaccination, including those groups outside the recommended vaccination age. It is expected to decrease further as more cohorts of children are vaccinated and herd immunity increases. PMID:18456699

  11. PM2.5 chemical composition in five European Mediterranean cities: A 1-year study

    NASA Astrophysics Data System (ADS)

    Salameh, Dalia; Detournay, Anais; Pey, Jorge; Pérez, Noemi; Liguori, Francesca; Saraga, Dikaia; Bove, Maria Chiara; Brotto, Paolo; Cassola, Federico; Massabò, Dario; Latella, Aurelio; Pillon, Silvia; Formenton, Gianni; Patti, Salvatore; Armengaud, Alexandre; Piga, Damien; Jaffrezo, Jean Luc; Bartzis, John; Tolis, Evangelos; Prati, Paolo; Querol, Xavier; Wortham, Henri; Marchand, Nicolas

    2015-03-01

    The seasonal and spatial characteristics of PM2.5 and its chemical composition in the Mediterranean Basin have been studied over a 1-year period (2011-2012) in five European Mediterranean cities: Barcelona (BCN), Marseille (MRS), Genoa (GEN), Venice (VEN), and Thessaloniki (THE). During the year under study, PM10 annual mean concentration ranged from 23 to 46 μg m- 3, while the respective PM2.5 ranged from 14 to 37 μg m- 3, with the highest concentrations observed in THE and VEN. Both cities presented an elevated number of exceedances of the PM10 daily limit value, as 32% and 20% of the days exceeded 50 μg m- 3, respectively. Similarly, exceedances of the WHO guidelines for daily PM2.5 concentrations (25 μg m- 3) were also more frequent in THE with 78% of the days during the period, followed by VEN with 39%. The lowest PM levels were measured in GEN. PM2.5 exhibited significant seasonal variability, with much higher winter concentrations for VEN and MRS, in fall for THE and in spring for BCN. PM2.5 chemical composition was markedly different even for similar PM2.5 levels. On annual average, PM2.5 was dominated by OM except in THE. OM contribution was higher in Marseille (42%), while mineral matter was the most abundant constituent in THE (32%). Moreover, PM2.5 relative mean composition during pollution episodes (PM2.5 > 25 μg m- 3) as well as the origins of the exceedances were also investigated. Results outline mainly the effect of NO3- being the most important driver and highlight the non-negligible impact of atmospheric mixing and aging processes during pollution episodes.

  12. Deep Sclerectomy With a New Nonabsorbable Uveoscleral Implant (Esnoper-Clip): 1-Year Outcomes

    PubMed Central

    Parera-Arranz, Angels; Romera-Romera, Pau; Castellvi-Manent, Jordi; Sabala-Llopart, Antoni; de la Cámara-Hermoso, Julio

    2015-01-01

    Purpose: To report the safety and the effectiveness of deep sclerectomy (DS) with a new nonabsorbable uveoscleral hema implant (Esnoper-Clip) designed to increase trabecular and uveoscleral outflow and to achieve higher intrascleral blebs. Materials and Methods: Twenty-seven eyes of 27 patients with open-angle glaucoma, who underwent DS with an Esnoper-Clip implant, were included in this study. All patients were followed up after 12 months. Results: A significant decrease in intraocular pressure was observed after surgery, changing from a preoperative mean of 26.6±5.2 mm Hg to a postoperative mean of 15.3±5 mm Hg (P<0.001) at 12 months. There was also a significant reduction in the number of glaucoma drugs needed, varying from 2.5 per patient to 0.3 (P<0.001) 1 year after surgery. The main intrascleral lake height and volume at 12 months was 0.7±0.1 mm and 3.9±1.3 mm3, respectively. No intraoperative complications occurred. The main postoperative complications were a positive Seidel test result at 24 hours in 2 eyes (7.4%), hyphema in 2 eyes (7.4%), and choroidal detachment in 1 eye (3.7%). All these complications resolved successfully. The need for additional mitomycin-C injections was recorded in 4 eyes (14.8%), twice in 2 of them. Twelve eyes (44.4%) underwent postsurgical Nd:YAG laser goniopuncture with a mean time between surgery and this procedure of 4.3 months. Mean intraocular pressure after Nd:YAG laser goniopuncture decreased from 19.2 to 15.5 mm Hg (P<0.001). Conclusion: DS with an uveoscleral hema implant (Esnoper-Clip) is a safe and effective technique for the management of open-angle glaucoma. PMID:25836660

  13. Repeat stereotactic radiosurgery as salvage therapy for locally recurrent brain metastases previously treated with radiosurgery.

    PubMed

    McKay, Will H; McTyre, Emory R; Okoukoni, Catherine; Alphonse-Sullivan, Natalie K; Ruiz, Jimmy; Munley, Michael T; Qasem, Shadi; Lo, Hui-Wen; Xing, Fei; Laxton, Adrian W; Tatter, Stephen B; Watabe, Kounosuke; Chan, Michael D

    2016-08-05

    OBJECTIVE There are a variety of salvage options available for patients with brain metastases who experience local failure after stereotactic radiosurgery (SRS). These options include resection, whole-brain radiation therapy, laser thermoablation, and repeat SRS. There is little data on the safety and efficacy of repeat SRS following local failure of a prior radiosurgical procedure. This study evaluates the clinical outcomes and dosimetric characteristics of patients who experienced tumor recurrence and were subsequently treated with repeat SRS. METHODS Between 2002 and 2015, 32 patients were treated with repeat SRS for local recurrence of ≥ 1 brain metastasis following initial SRS treatment. The Kaplan-Meier method was used to estimate time-to-event outcomes including overall survival (OS), local failure, and radiation necrosis. Cox proportional hazards analysis was performed for predictor variables of interest for each outcome. Composite dose-volume histograms were constructed for each reirradiated lesion, and these were then used to develop a predictive dosimetric model for radiation necrosis. RESULTS Forty-six lesions in 32 patients were re-treated with a second course of SRS after local failure. A median dose of 20 Gy (range 14-22 Gy) was delivered to the tumor margin at the time of repeat SRS. Local control at 1 year was 79% (95% CI 67%-94%). Estimated 1-year OS was 70% (95% CI 55%-88%). Twelve patients had died at the most recent follow-up, with 8/12 patients experiencing neurological death (as described in Patchell et al.). Eleven of 46 (24%) lesions in 11 separate patients treated with repeat SRS were associated with symptomatic radiation necrosis. Freedom from radiation necrosis at 1 year was 71% (95% CI 57%-88%). Analysis of dosimetric data revealed that the volume of a lesion receiving 40 Gy (V40Gy) was the most predictive factor for the development of radiation necrosis (p = 0.003). The following V40Gy thresholds were associated with 10%, 20%, and 50

  14. Integrated speech enhancement for functional MRI environment.

    PubMed

    Pathak, Nishank; Milani, Ali A; Panahi, Issa; Briggs, Richard

    2009-01-01

    This paper presents an integrated speech enhancement (SE) method for the noisy MRI environment. We show that the performance of SE system improves considerably when the speech signal dominated by MRI acoustic noise at very low SNR is enhanced in two successive stages using two-channel SE methods followed by a single-channel post processing SE algorithm. Actual MRI noisy speech data are used in our experiments showing the improved performance of the proposed SE method.

  15. Computerized Interpretation of Dynamic Breast MRI

    DTIC Science & Technology

    2005-05-01

    malignant and benign lesions. Keywords: Fuzzy c- means , breast cancer, contrast-enhanced MRI, tumor heterogeneity, computer-aided diag- nosis (CAD) 1...applications. tumor response to therapy[3]. Furthermore, breast MRI can In this paper, we present a fast fuzzy c- means (FCM) based be used for quantitative...use of a fuzzy c- means (FCM) algorithm for the assessment of 3-D tumor extent from contrast-enhanced magnetic resonance images (CE-MRI) of the breast

  16. MRI Scans - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Resonance Imaging) (Arabic) العربية Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) MRI (Magnetic Resonance Imaging) 核磁共振成像(MRI) - 简体中文 (Chinese - Simplified) Bilingual PDF Health Information Translations Chinese - Traditional (繁體中文) MRI (Magnetic Resonance Imaging) 核磁共振成像( ...

  17. MRI of nasopharyngeal adenoid hypertrophy.

    PubMed

    Surov, Alexey; Ryl, Ina; Bartel-Friedrich, Sylvia; Wienke, Andreas; Kösling, Sabrina

    2016-10-01

    Nasopharyngeal adenoid hypertrophy (NAH) is a typical benign lesion. Due to involution, nasopharyngeal lymphatic tissue usually is not found in adults beyond the 30th to 40th year of life. However, occasionally NAH has been recognized after the 50th or 60th year. The aim of this study is to identify the frequency of NAH and to analyze its MRI findings in different age groups. From 2007 to 2011, 6693 MR investigations of the head were performed at our institution. MRI was obtained with a 1.5 T MRI device. NAH was identified in 18.0% of the patients. The frequency of NAH varied from 60.3% to 1.0% in the different age groups. The mean size of NAH was 23.2 ± 4.5 mm in cranio-caudal, 31.1 ± 5.2 mm in left-right, and 14.2 ± 4.1 mm in the anterior-posterior direction. The left-right and cranio-caudal sizes of NAH were largest in the 0-9 age group and decreased with age. On T1-w images most lesions (95.4%) were hypointense in comparison to the adjacent musculature. On T2-w fat-saturated images 82.4% of the lesions were hyperintense. After intravenous administration of contrast medium most lesions showed a slight enhancement (58.6%). Moderate enhancement was seen in 32.4% and a marked enhancement was identified in 9.0%. In the 0-9 age group most lesions showed a slight enhancement. Cysts within NAH were identified in 433 cases (35.9%). The frequency of cysts increased continuously with age, namely from 10.9% to 65.2%.

  18. A Comparison of DWI Repeaters and Non-repeaters Who Attended a Level I Rehabilitation Program.

    ERIC Educational Resources Information Center

    Landrum, James W.; Windham, Gerald O.

    1981-01-01

    Compares behavioral and demographic characteristics of drunk drivers with repeated arrests and drivers not having repeated arrests, after attending an alcohol education program. Previous public drunkeness and previous drunk driving arrests were strong predictors of repeat arrests and were judged useful in screening offenders for rehabilitation…

  19. Repeated Testing Produces Superior Transfer of Learning Relative to Repeated Studying

    ERIC Educational Resources Information Center

    Butler, Andrew C.

    2010-01-01

    The present research investigated whether test-enhanced learning can be used to promote transfer. More specifically, 4 experiments examined how repeated testing and repeated studying affected retention and transfer of facts and concepts. Subjects studied prose passages and then either repeatedly restudied or took tests on the material. One week…

  20. Healing of extraction sockets and augmented alveolar defects following 1-year treatment with bisphosphonate.

    PubMed

    Khojasteh, Arash; Behnia, Hossein; Morad, Golnaz; Dashti, Seyedeh Ghazaleh; Dehghan, Mohammad Mehdi; Shahab, Shahriyar; Abbas, Fatemeh Mashhadi

    2013-01-01

    To assess the effect of bisphosphonates on healing of extraction sockets and augmented alveolar defects, 12 adult female mongrel dogs were assigned to 2 experimental groups and a control group. The experimental groups received oral alendronate (ALN, 3.5 mg/kg/wk) or IV pamidronate (PAM, 1 mg/kg/wk) for 12 months. Animals were randomly tested for serum C-terminal telopeptide of collagen I (CTx). The right first and second premolars were extracted. After 8 weeks, extraction sites were evaluated for healing. Subsequently, 3-wall defects were created in ridges and filled with human mineralized cortical particulate bone. Two months post-augmentation, animals were sacrificed and mandibles were collected for cone-beam computed tomography (CBCT) and histomorphometric appraisal. The obtained data were compared using 1-way ANOVA test. CTx test results in both experimental groups were comparable (<10 pg/mL) but lower than that of the control group (minimum 159.2 pg/mL). Two months post-extraction, bone sequestra were noticed in extraction sites in BP-treated groups, involving the entire alveolar bone in the PAM group and the upper rim of the alveoli in the ALN group. Histologically, bone sequestra from the PAM group demonstrated empty osteocyte lacunae, while in the ALN group areas of necrotic bone along with evidence of active bone remodeling was distinguished. Eight weeks post-augmentation, the experimental groups showed no evidence of bone formation in the augmented area, while bone formation ratio was measured to be 18.32% in the control group. The mean amount of pixel intensity calculated from the CBCT images of the ALN, PAM, and control group was 113.69 ± 11.04, 124.94 ± 4.72, and 113.69 ± 6.63, respectively. Pixel intensity in PAM-treated group was significantly higher than both other groups. This study demonstrated that 1-year treatment with ALN/PAM was associated with impairment of post-extraction and post-augmentation bone healing in dogs.

  1. Maternal weight change between 1 and 2 years postpartum: the importance of 1 year weight retention.

    PubMed

    Lipsky, Leah M; Strawderman, Myla S; Olson, Christine M

    2012-07-01

    Pregnancy weight gain may lead to long-term increases in maternal BMI for some women. The objective of this study was to examine maternal body weight change 1y-2y postpartum, and to compare classifications of 2y weight retention with and without accounting for 1y-2y weight gain. Early pregnancy body weight (EPW, first trimester) was measured or imputed, and follow-up measures obtained before delivery, 1 year postpartum (1y) and 2 years postpartum (2y) in an observational cohort study of women seeking prenatal care in several counties in upstate New York (n = 413). Baseline height was measured; demographic and behavioral data were obtained from questionnaires and medical records. Associations of 1y-2y weight change (kg) and 1y-2y weight gain (≥2.25 kg) with anthropometric, socioeconomic, and behavioral variables were evaluated using linear and logistic regressions. While mean ± SE 1y-2y weight change was 0.009 ± 4.6 kg, 1y-2y weight gain (≥2.25 kg) was common (n = 108, 26%). Odds of weight gain 1y-2y were higher for overweight (OR(adj) = 2.63, CI(95%) = 1.43-4.82) and obese (OR(adj) = 2.93, CI(95%) = 1.62-5.27) women than for women with BMI <25. Two year weight retention (2y-EPW ≥2.25 kg) was misclassified in 38% (n = 37) of women when 1y-2y weight gain was ignored. One year weight retention (1YWR) (1y-EPW) was negatively related to 1y-2y weight change (β(adj) ± SE = -0.28 ± 0.04, P < 0.001) and weight gain (≥2.25 kg) (OR(adj) = 0.91, CI(95%) = 0.87-0.95). Relations between 1y weight retention and 1y-2y weight change were attenuated for women with higher early pregnancy BMI. Weight change 1y-2y was predicted primarily by an inverse relation with 1y weight retention. The high frequency of weight gain has important implications for classification of postpartum weight retention.

  2. Functional Imaging: CT and MRI

    PubMed Central

    van Beek, Edwin JR; Hoffman, Eric A

    2008-01-01

    Synopsis Numerous imaging techniques permit evaluation of regional pulmonary function. Contrast-enhanced CT methods now allow assessment of vasculature and lung perfusion. Techniques using spirometric controlled MDCT allow for quantification of presence and distribution of parenchymal and airway pathology, Xenon gas can be employed to assess regional ventilation of the lungs and rapid bolus injections of iodinated contrast agent can provide quantitative measure of regional parenchymal perfusion. Advances in magnetic resonance imaging (MRI) of the lung include gadolinium-enhanced perfusion imaging and hyperpolarized helium imaging, which can allow imaging of pulmonary ventilation and .measurement of the size of emphysematous spaces. PMID:18267192

  3. MRI manifestations of bowler's thumb.

    PubMed

    Showalter, Martha F; Flemming, Donald J; Bernard, Stephanie A

    2011-01-01

    Bowler's thumb is a rare perineural fibrosis involving the ulnar digital nerve of the thumb. Affected patients present with pain, neuropathy, and mass lesion. The condition is caused by chronic repetitive impaction of the ulnar soft tissues of the thumb against the thumbhole of a bowling ball. In our case, MRI showed decreased signal intensity on both T1- and T2-weighted images surrounding an enlarged ulnar digital nerve of the thumb. The findings can be confused with giant-cell tumor of the tendon sheath or peripheral-nerve-sheath tumor.

  4. Surveillance of antimicrobial resistance among Escherichia coli in wastewater in Stockholm during 1 year: does it reflect the resistance trends in the society?

    PubMed

    Kwak, Young-Keun; Colque, Patricia; Byfors, Sara; Giske, Christian G; Möllby, Roland; Kühn, Inger

    2015-01-01

    The resistance patterns of Escherichia coli in untreated (raw) urban wastewater (UW) was monitored by repeated sampling during 1 year. Comparison with data from wastewater samples collected from hospital wastewater (HW) in the same urban area was made. A total of 1326 E. coli isolates from 17 UW samples and 451 isolates from six HW samples were analysed by typing using the PhenePlate™ system, and their susceptibility towards 10 antibiotics was determined. Resistance to at least one antibiotic was observed in 34% of the UW isolates and 55% of the HW isolates. For UW isolates, phenotypic diversity was lower among antibiotic-susceptible than among antibiotic-resistant isolates, indicating a higher presence of clonal groups among susceptible isolates. Total antibiotic resistance measured as the Multiple Antibiotic Resistance (MAR) index was 0.08 for UW compared with 0.19 for HW, and increased over time for UW isolates, indicating increasing resistance among E. coli in the urban population during the studied time period. Resistance to all included β-lactam antibiotics was detected in 2.4% of UW isolates and 14.0% of HW isolates, and 73/75 (97%) analysed isolates were confirmed to be extended-spectrum β-lactamase (including plasmid-mediated AmpC)-producing E. coli. Thus, by cultivating samples from wastewater and analysing many independent isolates per sample, increasing frequencies of antibiotic resistance in UW were detected during 1 year that may reflect increasing faecal carriage of resistant bacteria in the society. Surveillance of antibiotic resistance in wastewater could be a valuable tool for screening of resistance trends on a population level.

  5. Diffusion-Tensor MRI Based Skeletal Muscle Fiber Tracking.

    PubMed

    Damon, Bruce M; Buck, Amanda K W; Ding, Zhaohua

    2011-11-01

    A skeletal muscle's function is strongly influenced by the internal organization and geometric properties of its fibers, a property known as muscle architecture. Diffusion-tensor magnetic resonance imaging-based fiber tracking provides a powerful tool for non-invasive muscle architecture studies, has three-dimensional sensitivity, and uses a fixed frame of reference. Significant advances have been made in muscle fiber tracking technology, including defining seed points for fiber tracking, quantitatively characterizing muscle architecture, implementing denoising procedures, and testing validity and repeatability. Some examples exist of how these data can be integrated with those from other advanced MRI and computational methods to provide novel insights into muscle function. Perspectives are offered regarding future directions in muscle diffusion-tensor imaging, including needs to develop an improved understanding for the microstructural basis for reduced and anisotropic diffusion, establish the best practices for data acquisition and analysis, and integrate fiber tracking with other physiological data.

  6. MRI: update on technology diffusion and acquisition.

    PubMed

    Hoppszallern, S; Hughes, C; Zimmerman, R A

    1991-04-01

    Over the past three years, magnetic resonance imaging (MRI) has become accepted as a valuable diagnostic tool, and its applications continue to expand. During this time, the number of units installed in the United States doubled. By 1990 about 2,000 MRI units were in place in the United States and nearly 20 percent of the MRI-installed base was mobile, according to a research study conducted by the Hadley Hart Group (Chicago) and Drew Consultants, Inc. (Concord, MA). With the introduction of the prospective payment system, many hospitals were hesitant to spend limited capital on new technology, such as MRI. At the same time, freestanding diagnostic imaging centers were on the rise. Some hospitals and entrepreneurs who foresaw the potential of MRI in health care pioneered its use in the clinical setting. Hospitals began to examine new partnership arrangements and alternative forms of financing, so that they too could offer MRI services. By the end of 1988, the majority of hospitals offering MRI services did not own their own unit and about 40 percent of the hospitals offering MRI services were in a mobile configuration according to the Hadley Hart Group. While the technology has been diffused into 100-bed hospitals via mobile service vendors in some parts of the country, many medium-sized and large hospitals also have entered the MRI services market in this fashion. In the larger hospitals, the patient demand or need for the service often would justify acquisition of MRI, but the expense of the technology, and in many areas restrictive state health planning policies, modified purchase of MRI systems by hospitals. Mobile service vendors offered hospitals a way to startup MRI services in a limited fashion without a major capital expenditure and its associated risk. As hospitals gain experience with mobile MRI and achieve or exceed their early utilization projections, administrators are reevaluating the need to expand services to a full-time fixed site. Early fixed

  7. 4D flow imaging with MRI

    PubMed Central

    Stankovic, Zoran; Allen, Bradley D.; Garcia, Julio; Jarvis, Kelly B.

    2014-01-01

    Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed ‘4D flow MRI’) has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body. 4D flow MRI allows for the comprehensive evaluation of complex blood flow patterns by 3D blood flow visualization and flexible retrospective quantification of flow parameters. Recent technical developments, including the utilization of advanced parallel imaging techniques such as k-t GRAPPA, have resulted in reasonable overall scan times, e.g., 8-12 minutes for 4D flow MRI of the aorta and 10-20 minutes for whole heart coverage. As a result, the application of 4D flow MRI in a clinical setting has become more feasible, as documented by an increased number of recent reports on the utility of the technique for the assessment of cardiac and vascular hemodynamics in patient studies. A number of studies have demonstrated the potential of 4D flow MRI to provide an improved assessment of hemodynamics which might aid in the diagnosis and therapeutic management of cardiovascular diseases. The purpose of this review is to describe the methods used for 4D flow MRI acquisition, post-processing and data analysis. In addition, the article provides an overview of the clinical applications of 4D flow MRI and includes a review of applications in the heart, thoracic aorta and hepatic system. PMID:24834414

  8. MRI

    MedlinePlus

    ... sweatpants and a t-shirt). Certain types of metal can cause blurry images. You will lie on ... placed artificial joints Vascular stents Worked with sheet metal in the past (you may need tests to ...

  9. Repeated amphetamine treatment alters spinal magnetic resonance signals and pain sensitivity in mice.

    PubMed

    Lei, Bing-Hsuan; Chen, Jyh-Horng; Yin, Hsiang-Shu

    2014-11-07

    Manganese-enhanced magnetic resonance imaging (MEMRI) has been extensively used in studying the structural and functional features of the central nervous system (CNS). Divalent manganese ion (Mn(2+)) not only enhances MRI contrast, but also enters cells via voltage-gated calcium channels or ionotropic glutamate receptors, which represents an index of neural activities. In the current mouse model, following the repeated amphetamine (Amph) treatment, a reduction of reactivity to thermal pain stimulus was noticed. Since the spinal dorsal horn is the first relay station for pain transmission in CNS, we examined the changes of neural activity in the dorsal spinal cord, particularly the superficial dorsal horn, by analyzing manganese-enhanced T1-weighted MR images (T1WIs). Our data revealed a temporal correlation between reduced pain sensitivity and increased MEMR signals in the spinal dorsal horn subsequent to repeated Amph treatments.

  10. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Pan, Yuxi; Qiu, Rui; Gao, Linfeng; Ge, Chaoyong; Zheng, Junzheng; Xie, Wenzhang; Li, Junli

    2014-09-01

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations.

  11. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation.

    PubMed

    Pan, Yuxi; Qiu, Rui; Gao, Linfeng; Ge, Chaoyong; Zheng, Junzheng; Xie, Wenzhang; Li, Junli

    2014-09-21

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations.

  12. Physics of MRI: a primer.

    PubMed

    Plewes, Donald B; Kucharczyk, Walter

    2012-05-01

    This article is based on an introductory lecture given for the past many years during the "MR Physics and Techniques for Clinicians" course at the Annual Meeting of the ISMRM. This introduction is not intended to be a comprehensive overview of the field, as the subject of magnetic resonance imaging (MRI) physics is large and complex. Rather, it is intended to lay a conceptual foundation by which magnetic resonance image formation can be understood from an intuitive perspective. The presentation is nonmathematical, relying on simple models that take the reader progressively from the basic spin physics of nuclei, through descriptions of how the magnetic resonance signal is generated and detected in an MRI scanner, the foundations of nuclear magnetic resonance (NMR) relaxation, and a discussion of the Fourier transform and its relation to MR image formation. The article continues with a discussion of how magnetic field gradients are used to facilitate spatial encoding and concludes with a development of basic pulse sequences and the factors defining image contrast.

  13. Functional MRI using regularized parallel imaging acquisition.

    PubMed

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M; Belliveau, John W; Wald, Lawrence L; Kwong, Kenneth K

    2005-08-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions.

  14. Functional MRI Using Regularized Parallel Imaging Acquisition

    PubMed Central

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M.; Belliveau, John W.; Wald, Lawrence L.; Kwong, Kenneth K.

    2013-01-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions. PMID:16032694

  15. MRI endoscopy using intrinsically localized probes

    PubMed Central

    Sathyanarayana, Shashank; Bottomley, Paul A.

    2009-01-01

    Magnetic resonance imaging (MRI) is traditionally performed with fixed externally applied gradient magnetic fields and is hence intrinsically locked to the laboratory frame of reference (FoR). Here a method for high-resolution MRI that employs active, catheter-based, tiny internal probes that utilize the spatial properties of the probe itself for localization is proposed and demonstrated at 3 T. Because these properties are intrinsic to the probe, they move with it, transforming MRI from the laboratory FoR to the FoR of the device itself, analogous to an endoscope. The “MRI endoscope” can utilize loop coils and loopless antennas with modified sensitivity, in combination with adiabatic excitation by the device itself, to restrict the MRI sensitivity to a disk-shaped plane a few mm thick. Excitation with the MRI endoscope limits the eddy currents induced in the sample to an excited volume whose size is orders of magnitude below that excited by a conventional body MRI coil. Heat testing shows maximum local temperature increases of <1 °C during MRI, within regulatory guidelines. The method is demonstrated in a kiwifruit, in intact porcine and rabbit aortas, and in an atherosclerotic human iliac artery specimen, with in-plane resolution as small as 80 μm and 1.5–5 mm slice thickness. PMID:19378751

  16. Validation of Sodium MRI of Intervertebral Disc

    PubMed Central

    Wang, Chenyang; McArdle, Erin; Fenty, Matthew; Witschey, Walter; Elliott, Mark; Sochor, Matthew; Reddy, Ravinder; Borthakur, Arijitt

    2009-01-01

    Study Design This study demonstrated the diagnostic potential of sodium MRI for non-invasive quantification of PG in the intervertebral discs. Objective To determine the existence of a linear correlation between intervertebral disc [Na] measured from sodium MRI and [PG] measurement from DMMB assay. Summary of Background Data Previous studies have shown the possibility of quantifying [Na] in vivo using sodium MRI, however none has shown a direct linear correlation between [Na] measured from sodium MRI and [PG]. Methods 3D sodium MRI images of bovine discs were acquired and converted into [Na] maps. Samples were systematically removed from the discs for DMMB assay. The removal locations were photographically recorded and applied to the [Na] maps to extract the [Na] measurements for comparison. In vivo sodium MRI scans were also carried out on a pair of symptomatic and asymptomatic subjects. Results The linear regression fit of [Na] versus [PG] data yielded a significant linear correlation coefficient of 0.71. The in vivo sodium MRI image of the symptomatic subject showed significant [Na] decrease when compared to that of the asymptomatic subject. Conclusion Sodium MRI's specificity for PG in the intervertebral discs makes it a promising diagnostic tool for the earlier phase of disc degeneration. PMID:20147881

  17. Pantopaque simulating thrombosed intracranial aneurysms on MRI

    SciTech Connect

    Lidov, M.W.; Silvers, A.R.; Mosesson, R.E.; Stollman, A.L.; Som, P.M.

    1996-03-01

    A patient is presented in whom iophendylate (Pantopaque) within the basal cisterns closely resembled the appearance on MRI of thrombosed aneurysms of the middle cerebral arteries. The sometimes subtle differences between the appearances on MRI of Pantopaque and aneurysmal clot are discussed to permit accurate diagnosis without resorting to more invasive diagnostic tests, such as cerebral angiography. 5 refs., 4 figs.

  18. Anencephaly: MRI findings and pathogenetic theories.

    PubMed

    Calzolari, Ferdinando; Gambi, Beatrice; Garani, Giampaolo; Tamisari, Lalla

    2004-12-01

    We describe the MRI appearances of an anencephalic newborn who survived for 13 h; particularities of this case are male gender and the absence of other associated malformations. Moreover, we discuss the pathogenetic theories of anencephaly, correlating MRI findings with embryological data. An exencephaly-anencephaly sequence due to amnion rupture is hypothesized.

  19. [Anatomic variants of Meckel's cave on MRI].

    PubMed

    Benoudiba, F; Hadj-Rabia, M; Iffenecker, C; Fuerxer, F; Bekkali, F; Francke, J P; Doyon, D

    1998-10-01

    Magnetic resonance imaging (MRI) gives an accurate analysis of Meckel's cave variability. Images were acquired in 50 patients with several sections for anatomical comparison. Using several sections, MRI is a suitable method for better analysis of the trigeminal cistern. The most frequent findings are symmetrical trigeminal cisterns. Expansion of Meckel's cave or its disappearance has pathological significance.

  20. Long-term vascular access ports as a means of sedative administration in a rodent fMRI survival model.

    PubMed

    Hettinger, Patrick C; Li, Rupeng; Yan, Ji-Geng; Matloub, Hani S; Cho, Younghoon R; Pawela, Christopher P; Rowe, Daniel B; Hyde, James S

    2011-09-15

    The purpose of this study is to develop a rodent functional magnetic resonance imaging (fMRI) survival model with the use of heparin-coated vascular access devices. Such a model would ease the administration of sedative agents, reduce the number of animals required in survival experiments and eliminate animal-to-animal variability seen in previous designs. Seven male Sprague-Dawley rats underwent surgical placement of an MRI-compatible vascular access port, followed by implantable electrode placement on the right median nerve. Functional MRI during nerve stimulation and resting-state functional connectivity MRI (fcMRI) were performed at times 0, 2, 4, 8 and 12 weeks postoperatively using a 9.4T scanner. Anesthesia was maintained using intravenous dexmedetomidine and reversed using atipamezole. There were no fatalities or infectious complications during this study. All vascular access ports remained patent. Blood oxygen level dependent (BOLD) activation by electrical stimulation of the median nerve using implanted electrodes was seen within the forelimb sensory region (S1FL) for all animals at all time points. The number of activated voxels decreased at time points 4 and 8 weeks, returning to a normal level at 12 weeks, which is attributed to scar tissue formation and resolution around the embedded electrode. The applications of this experiment extend far beyond the scope of peripheral nerve experimentation. These vascular access ports can be applied to any survival MRI study requiring repeated medication administration, intravenous contrast, or blood sampling.

  1. NMR, MRI, and spectroscopic MRI in inhomogeneous fields

    DOEpatents

    Demas, Vasiliki; Pines, Alexander; Martin, Rachel W; Franck, John; Reimer, Jeffrey A

    2013-12-24

    A method for locally creating effectively homogeneous or "clean" magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength. THe method of imaging comprises: a) providing a functional approximation of an inhomogeneous static magnetic field strength B.sub.0({right arrow over (r)}) at a spatial position {right arrow over (r)}; b) providing a temporal functional approximation of {right arrow over (G)}.sub.shim(t) with i basis functions and j variables for each basis function, resulting in v.sub.ij variables; c) providing a measured value .OMEGA., which is an temporally accumulated dephasing due to the inhomogeneities of B.sub.0({right arrow over(r)}); and d) minimizing a difference in the local dephasing angle .phi.({right arrow over (r)},t)=.gamma..intg..sub.0.sup.t{square root over (|{right arrow over (B)}.sub.1({right arrow over (r)},t')|.sup.2+({right arrow over (r)}{right arrow over (G)}.sub.shimG.sub.shim(t')+.parallel.{right arrow over (B)}.sub.0({right arrow over (r)}).parallel..DELTA..omega.({right arrow over (r)},t'/.gamma/).sup.2)}dt'-.OMEGA. by varying the v.sub.ij variables to form a set of minimized v.sub.ij variables. The method requires calibration of the static fields prior to minimization, but may thereafter be implemented without such calibration, may be used in open or closed systems, and potentially portable systems.

  2. Epigenetics and Triplet-Repeat Neurological Diseases.

    PubMed

    Nageshwaran, Sathiji; Festenstein, Richard

    2015-01-01

    The term "junk DNA" has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterochromatinized resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, with several genes known to require such an environment to permit transcription. Repetitive regions frequently exist as dinucleotide, trinucleotide, and tetranucleotide repeats. The association between repetitive regions and disease was emphasized following the discovery of abnormal trinucleotide repeats underlying spinal and bulbar muscular atrophy (Kennedy's disease) and fragile X syndrome of mental retardation (FRAXA) in 1991. In this review, we provide a brief overview of epigenetic mechanisms and then focus on several diseases caused by DNA triplet-repeat expansions, which exhibit diverse epigenetic effects. It is clear that the emerging field of epigenetics is already generating novel potential therapeutic avenues for this group of largely incurable diseases.

  3. DNA Triplet Repeat Expansion and Mismatch Repair

    PubMed Central

    Iyer, Ravi R.; Pluciennik, Anna; Napierala, Marek; Wells, Robert D.

    2016-01-01

    DNA mismatch repair is a conserved antimutagenic pathway that maintains genomic stability through rectification of DNA replication errors and attenuation of chromosomal rearrangements. Paradoxically, mutagenic action of mismatch repair has been implicated as a cause of triplet repeat expansions that cause neurological diseases such as Huntington disease and myotonic dystrophy. This mutagenic process requires the mismatch recognition factor MutSβ and the MutLα (and/or possibly MutLγ) endonuclease, and is thought to be triggered by the transient formation of unusual DNA structures within the expanded triplet repeat element. This review summarizes the current knowledge of DNA mismatch repair involvement in triplet repeat expansion, which encompasses in vitro biochemical findings, cellular studies, and various in vivo transgenic animal model experiments. We present current mechanistic hypotheses regarding mismatch repair protein function in mediating triplet repeat expansions and discuss potential therapeutic approaches targeting the mismatch repair pathway. PMID:25580529

  4. Cumulative Effect of Repeated Brief Cerebral Ischemia

    DTIC Science & Technology

    1993-05-31

    KL, Pohost GM and Conger KA, Correlating EEG and Lactate Kinetics During Repeated Brief Cerebral Ischemia, Proceedings of the American Heart Association 1993...Cornelating EEG and Lactate Kinetics During Repeated Brief Cerebral Ischemia, Proceedings of the American Heart Association 1993. 4) HP Hetherington...thes Bernhard Foundation. ass- 134 󈧑&.1 n5. 9# American Heart Association 026085 66th Scientific Sessions Abstract Form Medical Research Nursing

  5. Newly arisen DNA repeats in primate phylogeny.

    PubMed

    Ryan, S C; Dugaiczyk, A

    1989-12-01

    We discovered the presence of an Alu and an Xba repetitive DNA element within introns 4 and 7, respectively, of the human alpha-fetoprotein (AFP) gene; these elements are absent from the same gene in the gorilla. The Alu element is flanked by 12-base-pair direct repeats, AGGATGTTGTGG ... (Alu) ... AGGATGTTGTGG, which presumably arose by way of duplication of the intronic target site AGGATGTTGTGG at the time of the Alu insertion. In the gorilla, only a single copy of the unoccupied target site is present, which is identical to the terminal repeat flanking the human Alu element. There are two copies of an Xba repeat in the human AFP gene, apparently the only two in the genome. Xba1 and Xba2, located within introns 8 and 7, respectively, differ from each other at 3 of 303 positions. Xba1 is referred to as the old (ancestral) repeat because it lacks direct repeats. The new (derived) Xba2 is flanked by direct repeats, TTTCTTTTT ... (Xba) ... TTTCTTCTT, and is thought to have arisen as a result of transposition of Xba1. The ancestral Xba1 and a single copy of the Xba2 target site are present at orthologous positions in the gorilla, but the new Xba2 is absent. We conclude that the Alu and Xba DNA repeats emerged in the human genome at a time postdating the human-gorilla divergence and became established as genetic novelties in the human lineage. We submit that the chronology of divergence of primate lines of evolution can be correlated with the timing of insertion of new DNA repeats into the genomes of those primates.

  6. Repeat radiosurgery for cerebral arteriovenous malformations

    PubMed Central

    Stapleton, Christopher J.; Ding, Dale; Leed, Cheng-Chia; Loeffler, Jay S.

    2015-01-01

    We perform a systematic review of repeated radiosurgery for cerebral arteriovenous malformations (AVM) with an emphasis on lesion obliteration rates and complications. Radiosurgery is an accepted treatment modality for AVM located in eloquent cortex or deep brain structures. For residual or persistent lesions, repeated radiosurgery can be considered if sufficient time has passed to allow for a full appreciation of treatment effects, usually at least 3 years. A systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. References for this review were identified by searches of MEDLINE, Web of Science and Google Scholar databases. A total of 14 studies comprising 733 patients met the review criteria and were included. For series that reported target dose at both first and repeat treatments, the weighted means were 19.42 Gy and 19.06 Gy, respectively. The mean and median obliteration rate for the repeat radiosurgery treatments were 61% (95% confidence interval 51.9–71.7%) and 61.5%, respectively. The median follow up following radiosurgery ranged from 19.5 to 80 months. Time to complete obliteration after the repeat treatment ranged from 21 to 40.8 months. The most common complications of repeated radiosurgery for AVM included hemorrhage (7.6%) and radiation-induced changes (7.4%). Repeat radiosurgery can be used to treat incompletely obliterated AVM with an obliteration rate of 61%. Complications are related to treatment effect latency (hemorrhage risk) as well as radiation-induced changes. Repeat radiosurgery can be performed at three years following the initial treatment, allowing for full realization of effects from the initial treatment prior to commencing therapy. PMID:25913746

  7. Influence of the psychological state of relatives on the quality of life of patients at 1 year after transplantation.

    PubMed

    Pérez-San-Gregorio, M A; Martín-Rodríguez, A; Pérez-Bernal, J

    2008-11-01

    We analyzed the influence of the psychological state of relatives on the quality of life of patients at 1 year after transplantation. We selected 2 groups: 94 transplant patients (47.9% liver, 40.4% kidney, and 11.7% heart) of mean age 49.42 years (SD, 11.21 years) and their close relatives (n = 94). All participants were assessed at 1 year after transplantation, using a Psychological Survey (both groups); the Hospital Anxiety and Depression Scale and the Quality of Life Questionnaire (transplant patients); and the Leeds Scales for the Self-Assessment of Anxiety and Depression (relatives). The results revealed that transplant patients whose relatives had more symptoms of anxiety and depression at 1 year after transplantation showed a decreased quality of life.

  8. Characteristics of young children with persistent conduct problems 1 year after treatment with the Incredible Years program.

    PubMed

    Drugli, May Britt; Fossum, Sturla; Larsson, Bo; Morch, Willy-Tore

    2010-07-01

    In the present study, predictors of persistent conduct problems among children aged 4-8 years were investigated in a randomized controlled trial 1 year after treatment with the Incredible Years parent training program (PT), or combined parent training and child treatment (PT + CT). Data were collected before and after treatment and at a 1-year follow-up. Pre-treatment child characteristics predicting persistent conduct problems in the child at the 1-year follow-up were high levels of internalizing and aggression problems as reported by mothers. The only family characteristic predicting persistence of child conduct problems was having contacts with child protection services. Clinicians and researchers need to closely monitor and identify children with conduct problems not responding to parent training programs. These individuals and their families are likely to need further support.

  9. Digital repeat analysis; setup and operation.

    PubMed

    Nol, J; Isouard, G; Mirecki, J

    2006-06-01

    Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors.

  10. Dynamic combinatorial libraries of artificial repeat proteins.

    PubMed

    Eisenberg, Margarita; Shumacher, Inbal; Cohen-Luria, Rivka; Ashkenasy, Gonen

    2013-06-15

    Repeat proteins are found in almost all cellular systems, where they are involved in diverse molecular recognition processes. Recent studies have suggested that de novo designed repeat proteins may serve as universal binders, and might potentially be used as practical alternative to antibodies. We describe here a novel chemical methodology for producing small libraries of repeat proteins, and screening in parallel the ligand binding of library members. The first stage of this research involved the total synthesis of a consensus-based three-repeat tetratricopeptide (TPR) protein (~14 kDa), via sequential attachment of the respective peptides. Despite the effectiveness of the synthesis and ligation steps, this method was found to be too demanding for the production of proteins containing variable number of repeats. Additionally, the analysis of binding of the individual proteins was time consuming. Therefore, we designed and prepared novel dynamic combinatorial libraries (DCLs), and show that their equilibration can facilitate the formation of TPR proteins containing up to eight repeating units. Interestingly, equilibration of the library building blocks in the presence of the biologically relevant ligands, Hsp90 and Hsp70, induced their oligomerization into forming more of the proteins with large recognition surfaces. We suggest that this work presents a novel simple and rapid tool for the simultaneous screening of protein mixtures with variable binding surfaces, and for identifying new binders for ligands of interest.

  11. Prognosis of stroke in the south of Greece: 1 year mortality, functional outcome and its determinants: the Arcadia Stroke Registry

    PubMed Central

    Vemmos, K; Bots, M; Tsibouris, P; Zis, V; Takis, C; Grobbee, D; Stamatelopoulos, S

    2000-01-01

    OBJECTIVES—For Greece, data on incidence of stroke, type of stroke, and prognosis of stroke is limited. Recently, results on incidence of stroke were published. Here 1 year mortality, functional outcome after a first ever stroke, and determinants of the prognosis are described.
METHODS—A population based registry was established in the Arcadia area, located in eastern central Peloponessos in southern Greece. Between 1 November 1993 and 31 October 1995, 555 patients with a first ever stroke were identified using information from death certificates, hospital records, public health centres and general practitioners. Extensive information on cardiovascular risk factors and stroke characteristics was obtained. After 1 year a modified Rankin score was determined in all surviving patients.
RESULTS—After 1 year of follow up, 204 (36.8%) patients died. The probability of survival 1 year after stroke was higher for cerebral infarction than for intracerebral haemorrhage; 67.8% (95% confidence interval (95% CI) 64-72) and 46.4% (35-57), respectively. Of the survivors, 68.9% had either no symptoms or symptoms that would not interfere with their capacity to look after themselves (Rankin score 0 to 2). Increasing age and low Glasgow coma scale score were the most powerful predictors of death within 1 year (p<0.01), whereas increasing age, atrial fibrillation, and low Glasgow coma scale score were the most important predictors of functional outcome 1 year after a stroke (p<0.01).
CONCLUSIONS—One year mortality from stroke in Greece is similar to that of other industrialised countries. The most important factors that affect the prognosis of a patient with a first ever stroke are increasing age, stroke severity, and atrial fibrillation.

 PMID:11032610

  12. Proliferating cell nuclear antigen prevents trinucleotide repeat expansions by promoting repeat deletion and hairpin removal

    PubMed Central

    Beaver, Jill M.; Lai, Yanhao; Rolle, Shantell J.; Liu, Yuan

    2017-01-01

    DNA base lesions and base excision repair (BER) within trinucleotide repeat (TNR) tracts modulate repeat instability through the coordination among the key BER enzymes DNA polymerase β, flap endonuclease 1 (FEN1) and DNA ligase I (LIG I). However, it remains unknown whether BER cofactors can also alter TNR stability. In this study, we discovered that proliferating cell nuclear antigen (PCNA), a cofactor of BER, promoted CAG repeat deletion and removal of a CAG repeat hairpin during BER in a duplex CAG repeat tract and CAG hairpin loop, respectively. We showed that PCNA stimulated LIG I activity on a nick across a small template loop during BER in a duplex (CAG)20 repeat tract promoting small repeat deletions. Surprisingly, we found that during BER in a hairpin loop, PCNA promoted reannealing of the upstream flap of a double-flap intermediate, thereby facilitating the formation of a downstream flap and stimulating FEN1 cleavage activity and hairpin removal. Our results indicate that PCNA plays a critical role in preventing CAG repeat expansions by modulating the structures of dynamic DNA via cooperation with BER enzymes. We provide the first evidence that PCNA prevents CAG repeat expansions during BER by promoting CAG repeat deletion and removal of a TNR hairpin. PMID:27793507

  13. Hemodynamic Nonlinearities Affect BOLD fMRI Response Timing and Amplitude

    PubMed Central

    de Zwart, Jacco A; van Gelderen, Peter; Jansma, J Martijn; Fukunaga, Masaki; Bianciardi, Marta; Duyn, Jeff H

    2009-01-01

    The interpretation of functional Magnetic Resonance Imaging (fMRI) studies based on Blood Oxygen-Level Dependent (BOLD) contrast generally relies on the assumption of a linear relationship between evoked neuronal activity and fMRI response. While nonlinearities in this relationship have been suggested by a number of studies, it remains unclear to what extent they relate to the neurovascular response and are therefore inherent to BOLD-fMRI. Full characterization of potential vascular nonlinearities is required for accurate inferences about the neuronal system under study. To investigate the extent of vascular nonlinearities, evoked activity was studied in humans with BOLD-fMRI (n=28) and Magnetoencephalography (MEG) (n=5). Brief (600-800 ms) rapidly repeated (1 Hz) visual stimuli were delivered using a stimulation paradigm that minimized neuronal nonlinearities. Nevertheless, BOLD-fMRI experiments showed substantial remaining nonlinearities. The smallest stimulus separation (200-400 ms) resulted in significant response broadening (15-20% amplitude decrease; 10-12% latency increase; 6-14% duration increase) with respect to a linear prediction. The substantial slowing and widening of the response in the presence of preceding stimuli suggests a vascular rather than neuronal origin to the observed non-linearity. This was confirmed by the MEG data, which showed no significant neuro-electric nonlinear interactions between stimuli as little as 200 ms apart. The presence of substantial vascular nonlinearities has important implications for rapid event-related studies by fMRI and other imaging modalities that infer neuronal activity from hemodynamic parameters. PMID:19520175

  14. Activity-induced manganese-dependent MRI (AIM-MRI) and functional MRI in awake rabbits during somatosensory stimulation

    PubMed Central

    Schroeder, Matthew P.; Weiss, Craig; Procissi, Daniel; Wang, Lei; Disterhoft, John F.

    2015-01-01

    Activity-induced manganese-dependent MRI (AIM-MRI) is a powerful tool to track system-wide neural activity using high resolution, quantitative T1-weighted MRI in animal models and has significant advantages for investigating neural activity over other modalities including BOLD fMRI. With AIM-MRI, Mn2+ ions enter neurons via voltage-gated calcium channels preferentially active during the time of experimental exposure. A broad range of AIM-MRI studies using different species studying different phenomena have been performed, but few of these studies provide a systematic evaluation of the factors influencing the detection of Mn2+ such as dosage and the temporal characteristics of Mn2+ uptake. We identified an optimal dose of Mn2+ (25 mg/kg, s.c.) in order to characterize the time-course of Mn2+ accumulation in active neural regions in the rabbit. T1-weighted MRI and functional MRI were collected 0–3, 6–9, and 24–27 h post-Mn2+ injection while the vibrissae on the right side were vibrated. Significant BOLD activation in the left somatosensory (SS) cortex and left ventral posteromedial (VPM) thalamic nucleus was detected during whisker vibration. T1-weighted signal intensities were extracted from these regions, their corresponding contralateral regions and the visual cortex (to serve as controls). A significant elevation in T1-weighted signal intensity in the left SS cortex (relative to right)was evident 6–9 and 24–27 h post-Mn2+ injection while the left VPM thalamus showed a significant enhancement (relative to the right) only during the 24–27 h session. Visual cortex showed no hemispheric difference at any timepoint. Our results suggest that studies employing AIM-MRI would benefit by conducting experimental manipulations 6–24 h after subcutaneous MnCl2 injections to optimize the concentration of contrast agent in the regions active during the exposure. PMID:26589332

  15. Portable MRI developed at Los Alamos

    SciTech Connect

    Espy, Michelle

    2015-04-22

    Scientists at Los Alamos National Laboratory are developing an ultra-low-field Magnetic Resonance Imaging (MRI) system that could be low-power and lightweight enough for forward deployment on the battlefield and to field hospitals in the World's poorest regions. "MRI technology is a powerful medical diagnostic tool," said Michelle Espy, the Battlefield MRI (bMRI) project leader, "ideally suited for imaging soft-tissue injury, particularly to the brain." But hospital-based MRI devices are big and expensive, and require considerable infrastructure, such as large quantities of cryogens like liquid nitrogen and helium, and they typically use a large amount of energy. "Standard MRI machines just can't go everywhere," said Espy. "Soldiers wounded in battle usually have to be flown to a large hospital and people in emerging nations just don't have access to MRI at all. We've been in contact with doctors who routinely work in the Third World and report that MRI would be extremely valuable in treating pediatric encephalopathy, and other serious diseases in children." So the Los Alamos team started thinking about a way to make an MRI device that could be relatively easy to transport, set up, and use in an unconventional setting. Conventional MRI machines use very large magnetic fields that align the protons in water molecules to then create magnetic resonance signals, which are detected by the machine and turned into images. The large magnetic fields create exceptionally detailed images, but they are difficult and expensive to make. Espy and her team wanted to see if images of sufficient quality could be made with ultra-low-magnetic fields, similar in strength to the Earth's magnetic field. To achieve images at such low fields they use exquisitely sensitive detectors called Superconducting Quantum Interference Devices, or SQUIDs. SQUIDs are among the most sensitive magnetic field detectors available, so interference with the signal is the primary stumbling block. "SQUIDs are

  16. Portable MRI developed at Los Alamos

    ScienceCinema

    Espy, Michelle

    2016-07-12

    Scientists at Los Alamos National Laboratory are developing an ultra-low-field Magnetic Resonance Imaging (MRI) system that could be low-power and lightweight enough for forward deployment on the battlefield and to field hospitals in the World's poorest regions. "MRI technology is a powerful medical diagnostic tool," said Michelle Espy, the Battlefield MRI (bMRI) project leader, "ideally suited for imaging soft-tissue injury, particularly to the brain." But hospital-based MRI devices are big and expensive, and require considerable infrastructure, such as large quantities of cryogens like liquid nitrogen and helium, and they typically use a large amount of energy. "Standard MRI machines just can't go everywhere," said Espy. "Soldiers wounded in battle usually have to be flown to a large hospital and people in emerging nations just don't have access to MRI at all. We've been in contact with doctors who routinely work in the Third World and report that MRI would be extremely valuable in treating pediatric encephalopathy, and other serious diseases in children." So the Los Alamos team started thinking about a way to make an MRI device that could be relatively easy to transport, set up, and use in an unconventional setting. Conventional MRI machines use very large magnetic fields that align the protons in water molecules to then create magnetic resonance signals, which are detected by the machine and turned into images. The large magnetic fields create exceptionally detailed images, but they are difficult and expensive to make. Espy and her team wanted to see if images of sufficient quality could be made with ultra-low-magnetic fields, similar in strength to the Earth's magnetic field. To achieve images at such low fields they use exquisitely sensitive detectors called Superconducting Quantum Interference Devices, or SQUIDs. SQUIDs are among the most sensitive magnetic field detectors available, so interference with the signal is the primary stumbling block. "SQUIDs are

  17. fMRI repetition suppression for familiar but not arbitrary actions with tools.

    PubMed

    Valyear, Kenneth F; Gallivan, Jason P; McLean, D Adam; Culham, Jody C

    2012-03-21

    For humans, daily life is characterized by routine interaction with many different tools for which corresponding actions are specified and performed according to well-learned procedures. The current study used functional MRI (fMRI) repetition suppression (RS) to identify brain areas underlying the transformation of visually defined tool properties to corresponding motor programs for conventional use. Before grasping and demonstrating how to use a specific tool, participants passively viewed either the same (repeated) tool or a different (non-repeated) tool. Repetition of tools led to reduced fMRI signals (RS) within a selective network of parietal and premotor areas. Comparison with newly learned, arbitrarily defined control actions revealed specificity of RS for tool use, thought to reflect differences in the extent of previous sensorimotor experience. The findings indicate that familiar tools are visually represented within the same sensorimotor areas underlying their dexterous use according to learned properties defined by previous experience. This interpretation resonates with the broader concept of affordance specification considered fundamental to action planning and execution whereby action-relevant object properties (affordances) are visually represented in sensorimotor areas. The current findings extend this view to reveal that affordance specification in humans includes learned object properties defined by previous sensorimotor experience. From an evolutionary perspective, the neural mechanisms identified in the current study offer clear survival advantage, providing fast efficient transformation of visual information to appropriate motor responses based on previous experience.

  18. Morphological asymmetries of mouse brain assessed by geometric morphometric analysis of MRI data.

    PubMed

    Barbeito-Andrés, Jimena; Bernal, Valeria; Gonzalez, Paula N

    2016-09-01

    Mammalian brain has repeated structures at both sides of the median plane, although some asymmetries have been described even under normal conditions. Characterizing normal patterns of asymmetry in mouse brain is important to recognize features that depart from expected ranges in the most widely used mammalian model. Analyses on brain morphology based on magnetic resonance image (MRI) have largely focused on volumes while less is known about shape asymmetry. We introduce a flexible protocol based on geometric morphometrics to assess patterns of asymmetry in shape and size of mouse brain from microMRI scans. After systematic digitization of landmarks and semilandmarks, we combine multivariate methods for statistical analyses with visualization tools to display the results. No preliminary treatment of the images (e.g. space normalization) is needed to collect data on MRI slices and visual representations improve the interpretation of the results. Results indicated that the protocol is highly repeatable. Asymmetry was more evident for shape than for size. Particularly, fluctuating asymmetry accounted for more variation than directional asymmetry in all brain regions. Since this approach can detect subtle shape variation between sides, it is a promising methodology to explore morphological changes in the brain of model organisms and can be applied in future studies addressing the effect of genetic and environmental factors on brain morphology.

  19. Techniques for Fast Stereoscopic MRI

    PubMed Central

    Guttman, Michael A.; McVeigh, Elliot R.

    2007-01-01

    Stereoscopic MRI can impart 3D perception with only two image acquisitions. This economy over standard multiplanar 3D volume renderings allows faster frame rates, which are needed for real-time imaging applications. Real-time 3D perception may enhance the appreciation of complex anatomical structures, and may improve hand-eye coordination while manipulating a medical device during an image-guided interventional procedure. To this goal, a system is being developed to acquire and display stereoscopic MR images in real-time. A clinically used, fast gradient-recalled echo-train sequence has been modified to produce stereo image pairs. Features have been added for depth cueing, view sharing, and bulk signal suppression. A workstation was attached to a clinical MR scanner for fast data extraction, image reconstruction and stereoscopic image display. PMID:11477636

  20. Combined PET/MRI scanner

    DOEpatents

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  1. Negative MRI versus real disease.

    PubMed

    Weinberg, D A

    1996-01-01

    A 76-year-old diabetic woman presented with progressive binocular vertical diplopia and right eye pain. Examination revealed a pupil-involving partial right third cranial nerve palsy, with development of anisocoria over the course of several hours. MRI of the brain showed no mass lesion. MRA, even with retrospective review of the images, failed to clearly identify a 1 cm right posterior communicating artery aneurysm detected by subsequent conventional cerebral angiography. While MRA has been reported to be highly sensitive in cerebral aneurysm detection at some centers, other investigators have indicated less favorable data. Standardized protocols for data acquisition and meticulous attention to proper post-processing and image interpretation are essential if MRA is to supplant invasive arteriography. Currently, conventional (x-ray) angiography remains the gold standard for aneurysm detection, while MRA possesses excellent potential in this regard.

  2. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  3. Feature space analysis of MRI

    NASA Astrophysics Data System (ADS)

    Soltanian-Zadeh, Hamid; Windham, Joe P.; Peck, Donald J.

    1997-04-01

    This paper presents development and performance evaluation of an MRI feature space method. The method is useful for: identification of tissue types; segmentation of tissues; and quantitative measurements on tissues, to obtain information that can be used in decision making (diagnosis, treatment planning, and evaluation of treatment). The steps of the work accomplished are as follows: (1) Four T2-weighted and two T1-weighted images (before and after injection of Gadolinium) were acquired for ten tumor patients. (2) Images were analyed by two image analysts according to the following algorithm. The intracranial brain tissues were segmented from the scalp and background. The additive noise was suppressed using a multi-dimensional non-linear edge- preserving filter which preserves partial volume information on average. Image nonuniformities were corrected using a modified lowpass filtering approach. The resulting images were used to generate and visualize an optimal feature space. Cluster centers were identified on the feature space. Then images were segmented into normal tissues and different zones of the tumor. (3) Biopsy samples were extracted from each patient and were subsequently analyzed by the pathology laboratory. (4) Image analysis results were compared to each other and to the biopsy results. Pre- and post-surgery feature spaces were also compared. The proposed algorithm made it possible to visualize the MRI feature space and to segment the image. In all cases, the operators were able to find clusters for normal and abnormal tissues. Also, clusters for different zones of the tumor were found. Based on the clusters marked for each zone, the method successfully segmented the image into normal tissues (white matter, gray matter, and CSF) and different zones of the lesion (tumor, cyst, edema, radiation necrosis, necrotic core, and infiltrated tumor). The results agreed with those obtained from the biopsy samples. Comparison of pre- to post-surgery and radiation

  4. Intra voxel analysis in MRI

    NASA Astrophysics Data System (ADS)

    Ambrosanio, Michele; Baselice, Fabio; Ferraioli, Giampaolo; Pascazio, Vito

    2014-03-01

    A new application of Compressive Sensing (CS) in Magnetic Resonance Imaging (MRI) field is presented. In particular, first results of the Intra Voxel Analysis (IVA) technique are reported. The idea is to exploit CS peculiarities in order to distinguish different contributions inside the same resolution cell, instead of reconstructing images from not fully sampled k-space acquisition. Applied to MRI field, this means the possibility of estimating the presence of different tissues inside the same voxel, i.e. in one pixel of the obtained image. In other words, the method is the first attempt, as far as we know, of achieving Spectroscopy-like results starting from each pixel of MR images. In particular, tissues are distinguished each others by evaluating their spin-spin relaxation times. Within this manuscript, first results on clinical dataset, in particular a phantom made by aqueous solution and oil and an occipital brain lesion corresponding to a metastatic breast cancer nodule, are reported. Considering the phantom dataset, in particular focusing on the slice where the separation between water and oil occurs, the methodology is able to distinguish the two components with different spin-spin relaxation times. With respect to clinical dataset,focusing on a voxel of the lesion area, the approach is able to detect the presence of two tissues, namely the healthy and the cancer related ones, while in other location outside the lesion only the healthy tissue is detected. Of course, these are the first results of the proposed methodology, further studies on different types of clinical datasets are required in order to widely validate the approach. Although few datasets have been considered, results seem both interesting and promising.

  5. [A case of neuro-Behçet's disease with repeating isolated thoracic spinal cord lesion].

    PubMed

    Shiote, Mito; Kido, Yukiko; Hayashi, Takeshi; Manabe, Yasuhiro; Kashihara, Ken-ichi; Nagano, Isao; Shoji, Mikio; Abe, Koji

    2003-06-01

    We reported a 45-year-old man who had repeated isolated thoracic spinal cord lesion on MRI in the clinical course of seven years. He had transient bilateral plantar numbness and urinary retention on December, 1994. Then, spastic paraplegia, total anesthesia of feet, and severe sphincter disturbance struck him on May, 1995. He was diagnosed as incomplete Behçet's disease and neuro-Behçet's disease on June, 1995 because of recurrent oral aphta, genital ulceration, and foliculitis. T2-weighted magnetic resonance imaging showed high intensity enhanced with Gd-DTPA in thoracic spinal cord from Th 5 to 8 level. Any other abnormal lesion on brain or spinal MRI was not observed. He was treated with corticosteroids and recovered incompletely. Another two big attacks occurred to him. No new lesion but thoracic spinal cord lesion was observed. We conclude that this case is the first reported example of neuro-Behçet's disease with repeating isolated thoracic spinal cord lesion.

  6. Low-Cost High-Performance MRI

    PubMed Central

    Sarracanie, Mathieu; LaPierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-01-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5–3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices. PMID:26469756

  7. Visualizing electromagnetic fields in metals by MRI

    NASA Astrophysics Data System (ADS)

    Chandrashekar, Chandrika Sefcikova; Shellikeri, Annadanesh; Chandrashekar, S.; Taylor, Erika A.; Taylor, Deanne M.

    2017-02-01

    Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface, decay exponentially inside the conductor, leading to a virtual absence of EM fields at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present a visualization of a virtual EM vacuum inside a bulk metal strip by MRI, amongst several findings. At its simplest, an MRI image is an intensity map of density variations across voxels (pixels) of identical size (=Δ x Δ y Δ z ). By contrast in bulk metal MRI, we uncover that despite uniform density, intensity variations arise from differing effective elemental volumes (voxels) from different parts of the bulk metal. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expected to grow in importance. The findings here may impact further development of bulk metal MRI and CSI.

  8. MRI visualisation by digitally reconstructed radiographs

    NASA Astrophysics Data System (ADS)

    Serrurier, Antoine; Bönsch, Andrea; Lau, Robert; Deserno, Thomas M.

    2015-03-01

    Visualising volumetric medical images such as computed tomography and magnetic resonance imaging (MRI) on picture archiving and communication systems (PACS) clients is often achieved by image browsing in sagittal, coronal or axial views or three-dimensional (3D) rendering. This latter technique requires fine thresholding for MRI. On the other hand, computing virtual radiograph images, also referred to as digitally reconstructed radiographs (DRR), provides in a single two-dimensional (2D) image a complete overview of the 3D data. It appears therefore as a powerful alternative for MRI visualisation and preview in PACS. This study describes a method to compute DRR from T1-weighted MRI. After segmentation of the background, a histogram distribution analysis is performed and each foreground MRI voxel is labeled as one of three tissues: cortical bone, also known as principal absorber of the X-rays, muscle and fat. An intensity level is attributed to each voxel according to the Hounsfield scale, linearly related to the X-ray attenuation coefficient. Each DRR pixel is computed as the accumulation of the new intensities of the MRI dataset along the corresponding X-ray. The method has been tested on 16 T1-weighted MRI sets. Anterior-posterior and lateral DRR have been computed with reasonable qualities and avoiding any manual tissue segmentations. This proof-of-concept holds for research application for use in clinical PACS.

  9. Recommendations for Real-Time Speech MRI

    PubMed Central

    Lingala, Sajan Goud; Sutton, Brad P.; Miquel, Marc E.; Nayak, Krishna S.

    2016-01-01

    Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specific guidance for new groups entering this field. We provide recommendations for performing RT-MRI of the upper airway. This is a consensus statement stemming from the ISMRM-endorsed Speech MRI summit held in Los Angeles, February 2014. A major unmet need identified at the summit was the need for consensus on protocols that can be easily adapted by researchers equipped with conventional MRI systems. To this end, we provide a discussion of tradeoffs in RT-MRI in terms of acquisition requirements, a priori assumptions, artifacts, computational load, and performance for different speech tasks. We provide four recommended protocols and identify appropriate acquisition and reconstruction tools. We list pointers to open-source software that facilitate implementation. We conclude by discussing current open challenges in the methodological aspects of RT-MRI of speech. PMID:26174802

  10. Low-Cost High-Performance MRI

    NASA Astrophysics Data System (ADS)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.

  11. Procedural learning and associative memory mechanisms contribute to contextual cueing: Evidence from fMRI and eye-tracking.

    PubMed

    Manelis, Anna; Reder, Lynne M

    2012-10-16

    Using a combination of eye tracking and fMRI in a contextual cueing task, we explored the mechanisms underlying the facilitation of visual search for repeated spatial configurations. When configurations of distractors were repeated, greater activation in the right hippocampus corresponded to greater reductions in the number of saccades to locate the target. A psychophysiological interactions analysis for repeated configurations revealed that a strong functional connectivity between this area in the right hippocampus and the left superior parietal lobule early in learning was significantly reduced toward the end of the task. Practice related changes (which we call "procedural learning") in activation in temporo-occipital and parietal brain regions depended on whether or not spatial context was repeated. We conclude that context repetition facilitates visual search through chunk formation that reduces the number of effective distractors that have to be processed during the search. Context repetition influences procedural learning in a way that allows for continuous and effective chunk updating.

  12. Automated genotyping of dinucleotide repeat markers

    SciTech Connect

    Perlin, M.W.; Hoffman, E.P. |

    1994-09-01

    The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

  13. The effect of an official match on repeated sprint ability in junior basketball players.

    PubMed

    Caprino, Davide; Clarke, Neil David; Delextrat, Anne

    2012-01-01

    The aim of this study was to investigate the effect of an official basketball match on repeated sprint ability indices in male junior players. Ten (16 ± 1 years old; 183.6 ± 7.0 cm; 76.6 ± 8.0 kg) starting players for their teams performed three repeated sprint ability tests, before, at half-time and immediately after an official match. Each repeated sprint ability test consisted of 10 shuttle-run sprints of 30 m (15 + 15 m) separated by 30 seconds of passive recovery. The matches were video-taped to determine the frequency of eight types of movement patterns, and blood lactate concentration was measured before and immediately after each repeated sprint ability test. Differences in total time, ideal time and percentage decrement between tests was assessed by a one-way analysis of variance (ANOVA) with repeated measures, while a two-way ANOVA with repeated measures was used to identify differences in blood lactate concentration. The main results indicated a significant decrease in total movement frequency (-9.9%), high-intensity activity frequency (-13.3%), run frequency (-13.0%) and sprint frequency (-23.3%) in the second compared to the first half, and significantly worse total time and ideal time at the end of the match, compared to the start and half-time (differences ranging from -2.1% to -2.9%, P < 0.05). The practical implications of these findings suggest that regional basketball players should participate in conditioning sessions that focus on the improvement of repeated sprint ability.

  14. Influence of dental materials on dental MRI

    PubMed Central

    Tymofiyeva, O; Vaegler, S; Rottner, K; Boldt, J; Hopfgartner, AJ; Proff, PC; Richter, E-J; Jakob, PM

    2013-01-01

    Objectives: To investigate the potential influence of standard dental materials on dental MRI (dMRI) by estimating the magnetic susceptibility with the help of the MRI-based geometric distortion method and to classify the materials from the standpoint of dMRI. Methods: A series of standard dental materials was studied on a 1.5 T MRI system using spin echo and gradient echo pulse sequences and their magnetic susceptibility was estimated using the geometric method. Measurements on samples of dental materials were supported by in vivo examples obtained in dedicated dMRI procedures. Results: The tested materials showed a range of distortion degrees. The following materials were classified as fully compatible materials that can be present even in the tooth of interest: the resin-based sealer AH Plus® (Dentsply, Maillefer, Germany), glass ionomer cement, gutta-percha, zirconium dioxide and composites from one of the tested manufacturers. Interestingly, composites provided by the other manufacturer caused relatively strong distortions and were therefore classified as compatible I, along with amalgam, gold alloy, gold–ceramic crowns, titanium alloy and NiTi orthodontic wires. Materials, the magnetic susceptibility of which differed from that of water by more than 200 ppm, were classified as non-compatible materials that should not be present in the patient’s mouth for any dMRI applications. They included stainless steel orthodontic appliances and CoCr. Conclusions: A classification of the materials that complies with the standard grouping of materials according to their magnetic susceptibility was proposed and adopted for the purposes of dMRI. The proposed classification can serve as a guideline in future dMRI research. PMID:23610088

  15. A Novel MRI Marker for Prostate Brachytherapy

    SciTech Connect

    Frank, Steven J. Stafford, R. Jason; Bankson, James A.; Li Chun; Swanson, David A.; Kudchadker, Rajat J.; Martirosyan, Karen S.

    2008-05-01

    Purpose: Magnetic resonance imaging (MRI) is the optimal imaging modality for the prostate and surrounding critical organ structures. However, on MRI, the titanium radioactive seeds used for brachytherapy appear as black holes (negative contrast) and cannot be accurately localized. We sought to develop an encapsulated contrast agent marker (ECAM) with high-signal intensity on MRI to permit accurate localization of radioactive seeds with MRI during and after prostate brachytherapy. Methods and Materials: We investigated several agents with paramagnetic and superparamagnetic properties. The agents were injected into titanium, acrylic, and glass seeds, which were linked together in various combinations and imaged with MRI. The agent with the greatest T1-weighted signal was tested further in a canine prostate and agarose phantom. Studies were performed on a 1.5-T clinical MRI scanner. Results: The cobalt-chloride complex contrast (C4) agent with stoichiometry (CoCl{sub 2}){sub 0.8}(C{sub 2}H{sub 5}NO{sub 2}){sub 0.2} had the greatest T1-weighted signal (positive contrast) with a relaxivity ratio >1 (r{sub 2}/r{sub 1} = 1.21 {+-} 0.29). Acrylic-titanium and glass-titanium seed strands were clearly visualized with the encapsulated contrast agent marker. Conclusion: We have developed a novel ECAM that permits positive identification of the radioactive seeds used for prostate brachytherapy on MRI. Preclinical in vitro phantom studies and in vivo canine studies are needed to further optimize MRI sequencing techniques to facilitate MRI-based dosimetry.

  16. Synthetic quantitative MRI through relaxometry modelling

    PubMed Central

    Mohammadi, Siawoosh; Weiskopf, Nikolaus

    2016-01-01

    Abstract Quantitative MRI (qMRI) provides standardized measures of specific physical parameters that are sensitive to the underlying tissue microstructure and are a first step towards achieving maps of biologically relevant metrics through in vivo histology using MRI. Recently proposed models have described the interdependence of qMRI parameters. Combining such models with the concept of image synthesis points towards a novel approach to synthetic qMRI, in which maps of fundamentally different physical properties are constructed through the use of biophysical models. In this study, the utility of synthetic qMRI is investigated within the context of a recently proposed linear relaxometry model. Two neuroimaging applications are considered. In the first, artefact‐free quantitative maps are synthesized from motion‐corrupted data by exploiting the over‐determined nature of the relaxometry model and the fact that the artefact is inconsistent across the data. In the second application, a map of magnetization transfer (MT) saturation is synthesized without the need to acquire an MT‐weighted volume, which directly leads to a reduction in the specific absorption rate of the acquisition. This feature would be particularly important for ultra‐high field applications. The synthetic MT map is shown to provide improved segmentation of deep grey matter structures, relative to segmentation using T 1‐weighted images or R 1 maps. The proposed approach of synthetic qMRI shows promise for maximizing the extraction of high quality information related to tissue microstructure from qMRI protocols and furthering our understanding of the interrelation of these qMRI parameters. PMID:27753154

  17. Single element ultrasonic imaging of limb geometry: an in-vivo study with comparison to MRI

    NASA Astrophysics Data System (ADS)

    Zhang, Xiang; Fincke, Jonathan R.; Anthony, Brian W.

    2016-04-01

    Despite advancements in medical imaging, current prosthetic fitting methods remain subjective, operator dependent, and non-repeatable. The standard plaster casting method relies on prosthetist experience and tactile feel of the limb to design the prosthetic socket. Often times, many fitting iterations are required to achieve an acceptable fit. Use of improper socket fittings can lead to painful pathologies including neuromas, inflammation, soft tissue calcification, and pressure sores, often forcing the wearer to into a wheelchair and reducing mobility and quality of life. Computer software along with MRI/CT imaging has already been explored to aid the socket design process. In this paper, we explore the use of ultrasound instead of MRI/CT to accurately obtain the underlying limb geometry to assist the prosthetic socket design process. Using a single element ultrasound system, multiple subjects' proximal limbs were imaged using 1, 2.25, and 5 MHz single element transducers. Each ultrasound transducer was calibrated to ensure acoustic exposure within the limits defined by the FDA. To validate image quality, each patient was also imaged in an MRI. Fiducial markers visible in both MRI and ultrasound were used to compare the same limb cross-sectional image for each patient. After applying a migration algorithm, B-mode ultrasound cross-sections showed sufficiently high image resolution to characterize the skin and bone boundaries along with the underlying tissue structures.

  18. Genetic evaluation of weaning weight and probability of lambing at 1 year of age in Targhee lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to investigate genetic control of 120-day weaning weight and the probability of lambing at 1 year of age in Targhee ewe lambs. Records of 5,967 ewe lambs born from 1989 to 2012 and first exposed to rams for breeding at approximately 7 months of age were analyzed. Reco...

  19. Risperidone in Children with Disruptive Behavior Disorders and Subaverage Intelligence: A 1-Year, Open-Label Study of 504 Patients

    ERIC Educational Resources Information Center

    Croonenberghs, Jan; Fegert, Joerg M.; Findling, Robert L.; de Smedt, Goedele; van Dongen, Stefan

    2005-01-01

    Objective: To determine the long-term safety and effectiveness of risperidone for severe disruptive behaviors in children. Method: A multisite, 1-year, open-label study of patients aged 5 to 14 years with disruptive behaviors and subaverage intelligence was conducted. Results: Seventy-three percent of the 504 patients enrolled completed the study.…

  20. [The pharyngeal viral flora in dystrophic infants 0 to 1 years of age with acute respiratory diseases].

    PubMed

    Pârvu, C; Isaia, G; Moldovan, D; Mârşanu, M; Lăzărescu, P; Sîntimbreanu, C; Mârşanu, A

    1989-01-01

    Pharyngeal viral flora was studied in 0-1-year-old dystrophic children with acute infections of the upper respiratory tract and with interstitial pneumopathy. Influence of the dystrophic factor on the qualitative and quantitative aspects of the viral flora is discussed.

  1. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  2. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  3. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  4. Decrease in Television Viewing Predicts Lower Body Mass Index at 1-Year Follow-Up in Adolescents, but Not Adults

    ERIC Educational Resources Information Center

    French, Simone A.; Mitchell, Nathan R.; Hannan, Peter J.

    2012-01-01

    Objective: To examine associations between television viewing, sugar-sweetened beverage consumption, eating out, physical activity, and body weight change over 1 year. Design: Secondary data analysis from randomized intervention trial. Setting: Households in the community. Participants: Adults (n = 153) and adolescents (n = 72) from the same…

  5. Improving Academic Performance of School-Age Children by Physical Activity in the Classroom: 1-Year Program Evaluation

    ERIC Educational Resources Information Center

    Mullender-Wijnsma, Marijke J.; Hartman, Esther; de Greeff, Johannes W.; Bosker, Roel J.; Doolaard, Simone; Visscher, Chris

    2015-01-01

    Background: An intervention was designed that combined physical activity with learning activities. It was based upon evidence for positive effects of moderate to vigorous physical activity (MVPA) on academic achievement. The aim of this study was to describe the program implementation and effects on academic achievement after 1?year. Methods:…

  6. Children's Spoken Word Recognition and Contributions to Phonological Awareness and Nonword Repetition: A 1-Year Follow-Up

    ERIC Educational Resources Information Center

    Metsala, Jamie L.; Stavrinos, Despina; Walley, Amanda C.

    2009-01-01

    This study examined effects of lexical factors on children's spoken word recognition across a 1-year time span, and contributions to phonological awareness and nonword repetition. Across the year, children identified words based on less input on a speech-gating task. For word repetition, older children improved for the most familiar words. There…

  7. Endovascular treatment of a bleeding secondary aorto-enteric fistula. A case report with 1-year follow-up.

    PubMed

    Brountzos, Elias N; Vasdekis, Spyros; Kostopanagiotou, Georgia; Danias, Nikolaos; Alexopoulou, Efthymia; Petropoulou, Konstantina; Gouliamos, Athanasios; Perros, Georgios

    2007-01-01

    We report a patient with life-threatening gastrointestinal bleeding caused by a secondary aorto-enteric fistula. Because the patient had several comorbid conditions, we succesfully stopped the bleeding by endovascular placement of a bifurcated aortic stent-graft. The patient developed periaortic infection 4 months later, but he was managed with antibiotics. The patient is well 1 year after the procedure.

  8. Variability in Measures of Health and Health Behavior among Emerging Adults 1 Year after High School According to College Status

    ERIC Educational Resources Information Center

    Simons-Morton, Bruce; Haynie, Denise; O'Brien, Fearghal; Lipsky, Leah; Bible, Joe; Liu, Danping

    2017-01-01

    Objective: To examine changes in health behaviors among US emerging adults 1 year after high school. Participants: The national sample of participants (N = 1,927), including those attending 4-year college/university (n = 884), 2-year colleges/technical schools (n = 588), and no college (n = 455), participated in annual spring surveys 2013-2014.…

  9. Treatment of bisphosphonate related osteonecrosis following root canal therapy at the 1-year follow-up: report of two cases

    PubMed Central

    Kaptan, Figen; Kazandag, Meric Karapinar; Iseri, Ufuk

    2013-01-01

    The objective of this report was to use topical gaseous ozone as an adjunct to conventional treatment methods and to describe the multidisciplinary management of bisphosphonate associated bone necrosis, which developed following endodontic treatment. No complaints were noted by the patients at their 1-year follow-up and the treatment showed favorable prognosis. PMID:24353427

  10. MRI findings in pediatric patients with scurvy.

    PubMed

    Gulko, Edwin; Collins, Lee K; Murphy, Robyn C; Thornhill, Beverly A; Taragin, Benjamin H

    2015-02-01

    In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia.

  11. Maximum entropy spherical deconvolution for diffusion MRI.

    PubMed

    Alexander, Daniel C

    2005-01-01

    This paper proposes a maximum entropy method for spherical deconvolution. Spherical deconvolution arises in various inverse problems. This paper uses the method to reconstruct the distribution of microstructural fibre orientations from diffusion MRI measurements. Analysis shows that the PASMRI algorithm, one of the most accurate diffusion MRI reconstruction algorithms in the literature, is a special case of the maximum entropy spherical deconvolution. Experiments compare the new method to linear spherical deconvolution, used previously in diffusion MRI, and to the PASMRI algorithm. The new method compares favourably both in simulation and on standard brain-scan data.

  12. Developments in boron magnetic resonance imaging (MRI)

    SciTech Connect

    Schweizer, M.

    1995-11-01

    This report summarizes progress during the past year on maturing Boron-11 magnetic resonance imaging (MRI) methodology for noninvasive determination of BNCT agents (BSH) spatially in time. Three major areas are excerpted: (1) Boron-11 MRI of BSH distributions in a canine intracranial tumor model and the first human glioblastoma patient, (2) whole body Boron-11 MRI of BSH pharmacokinetics in a rat flank tumor model, and (3) penetration of gadolinium salts through the BBB as a function of tumor growth in the canine brain.

  13. Role of memory errors in quantum repeaters

    NASA Astrophysics Data System (ADS)

    Hartmann, L.; Kraus, B.; Briegel, H.-J.; Dür, W.

    2007-03-01

    We investigate the influence of memory errors in the quantum repeater scheme for long-range quantum communication. We show that the communication distance is limited in standard operation mode due to memory errors resulting from unavoidable waiting times for classical signals. We show how to overcome these limitations by (i) improving local memory and (ii) introducing two operational modes of the quantum repeater. In both operational modes, the repeater is run blindly, i.e., without waiting for classical signals to arrive. In the first scheme, entanglement purification protocols based on one-way classical communication are used allowing to communicate over arbitrary distances. However, the error thresholds for noise in local control operations are very stringent. The second scheme makes use of entanglement purification protocols with two-way classical communication and inherits the favorable error thresholds of the repeater run in standard mode. One can increase the possible communication distance by an order of magnitude with reasonable overhead in physical resources. We outline the architecture of a quantum repeater that can possibly ensure intercontinental quantum communication.

  14. Spectrin repeat proteins in the nucleus.

    PubMed

    Young, Kevin G; Kothary, Rashmi

    2005-02-01

    Spectrin repeat sequences are among the more common repeat elements identified in proteins, typically occurring in large structural proteins. Examples of spectrin repeat-containing proteins include dystrophin, alpha-actinin and spectrin itself--all proteins with well-demonstrated roles of establishing and maintaining cell structure. Over the past decade, it has become clear that, although these proteins display a cytoplasmic and plasma membrane distribution, several are also found both at the nuclear envelope, and within the intranuclear space. In this review, we provide an overview of recent work regarding various spectrin repeat-containing structural proteins in the nucleus. As well, we hypothesize about the regulation of their nuclear localization and possible nuclear functions based on domain architecture, known interacting proteins and evolutionary relationships. Given their large size, and their potential for interacting with multiple proteins and with chromatin, spectrin repeat-containing proteins represent strong candidates for important organizational proteins within the nucleus. Supplementary material for this article can be found on the BioEssays website (http://www.interscience.wiley.com/jpages/0265-9247/suppmat/index.html).

  15. Barriers to Care and 1-Year Mortality Among Newly Diagnosed HIV-Infected People in Durban, South Africa

    PubMed Central

    Coleman, Sharon M.; Giddy, Janet; Bogart, Laura M.; Chaisson, Christine E.; Ross, Douglas; Flash, Moses J. E.; Govender, Tessa; Walensky, Rochelle P.; Freedberg, Kenneth A.; Losina, Elena

    2017-01-01

    Background: Prompt entry into HIV care is often hindered by personal and structural barriers. Our objective was to evaluate the impact of self-perceived barriers to health care on 1-year mortality among newly diagnosed HIV-infected individuals in Durban, South Africa. Methods: Before HIV testing at 4 outpatient sites, adults (≥18 years) were surveyed regarding perceived barriers to care including (1) service delivery, (2) financial, (3) personal health perception, (4) logistical, and (5) structural. We assessed deaths via phone calls and the South African National Population Register. We used multivariable Cox proportional hazards models to determine the association between number of perceived barriers and death within 1 year. Results: One thousand eight hundred ninety-nine HIV-infected participants enrolled. Median age was 33 years (interquartile range: 27–41 years), 49% were females, and median CD4 count was 192/μL (interquartile range: 72–346/μL). One thousand fifty-seven participants (56%) reported no, 370 (20%) reported 1–3, and 460 (24%) reported >3 barriers to care. By 1 year, 250 [13%, 95% confidence interval (CI): 12% to 15%] participants died. Adjusting for age, sex, education, baseline CD4 count, distance to clinic, and tuberculosis status, participants with 1–3 barriers (adjusted hazard ratio: 1.49, 95% CI: 1.06 to 2.08) and >3 barriers (adjusted hazard ratio: 1.81, 95% CI: 1.35 to 2.43) had higher 1-year mortality risk compared with those without barriers. Conclusions: HIV-infected individuals in South Africa who reported perceived barriers to medical care at diagnosis were more likely to die within 1 year. Targeted structural interventions, such as extended clinic hours, travel vouchers, and streamlined clinic operations, may improve linkage to care and antiretroviral therapy initiation for these people. PMID:28060226

  16. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges

    PubMed Central

    Macey, Paul M.; Schluter, Philip J.; Macey, Katherine E.; Harper, Ronald M.

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function “lme”. Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns

  17. Resting-state fMRI: a window into human brain plasticity.

    PubMed

    Guerra-Carrillo, Belén; Mackey, Allyson P; Bunge, Silvia A

    2014-10-01

    Although brain plasticity is greatest in the first few years of life, the brain continues to be shaped by experience throughout adulthood. Advances in fMRI have enabled us to examine the plasticity of large-scale networks using blood oxygen level-dependent (BOLD) correlations measured at rest. Resting-state functional connectivity analysis makes it possible to measure task-independent changes in brain function and therefore could provide unique insights into experience-dependent brain plasticity in humans. Here, we evaluate the hypothesis that resting-state functional connectivity reflects the repeated history of co-activation between brain regions. To this end, we review resting-state fMRI studies in the sensory, motor, and cognitive learning literature. This body of research provides evidence that the brain's resting-state functional architecture displays dynamic properties in young adulthood.

  18. Rate analysis for a hybrid quantum repeater

    SciTech Connect

    Bernardes, Nadja K.; Loock, Peter van

    2011-01-15

    We present a detailed rate analysis for a hybrid quantum repeater assuming perfect memories and using optimal probabilistic entanglement generation and deterministic swapping routines. The hybrid quantum repeater protocol is based on atomic qubit-entanglement distribution through optical coherent-state communication. An exact, analytical formula for the rates of entanglement generation in quantum repeaters is derived, including a study on the impacts of entanglement purification and multiplexing strategies. More specifically, we consider scenarios with as little purification as possible and we show that for sufficiently low local losses, such purifications are still more powerful than multiplexing. In a possible experimental scenario, our hybrid system can create near-maximally entangled (F=0.98) pairs over a distance of 1280 km at rates of the order of 100 Hz.

  19. Hematuria home screening: repeat testing results.

    PubMed

    Messing, E M; Young, T B; Hunt, V B; Newton, M A; Bram, L L; Vaillancourt, A; Hisgen, W J; Greenberg, E B; Kuglitsch, M E; Wegenke, J D

    1995-07-01

    To determine at what interval screening should be repeated to detect bladder cancer before it becomes muscle invasive 856 men who had 14 negative daily home tests for hematuria with a chemical reagent strip 9 months previously performed repeat tests. Of these men 50 (5.8%) had at least 1 positive test during the second 14-day screening period and 38 were evaluated, 15 of whom (39.5%) had significant urological pathological conditions, including 8 with malignancies. Bladder cancer was noted in 7 men, with no tumor invading the muscularis propria. The finding of 7 bladder cancers in 856 men (0.82%) who had a negative test 9 months previously indicates that bladder cancer has a brief preclinical duration and that testing must be repeated at least annually for screening to detect bladder cancer consistently before invasion occurs.

  20. Some characteristics of repeated sickness absence

    PubMed Central

    Ferguson, David

    1972-01-01

    Ferguson, D. (1972).Brit. J. industr. Med.,29, 420-431. Some characteristics of repeated sickness absence. Several studies have shown that frequency of absence attributed to sickness is not distributed randomly but tends to follow the negative binomial distribution, and this has been taken to support the concept of `proneness' to such absence. Thus, the distribution of sickness absence resembles that of minor injury at work demonstrated over 50 years ago. Because the investigation of proneness to absence does not appear to have been reported by others in Australia, the opportunity was taken, during a wider study of health among telegraphists in a large communications undertaking, to analyse some characteristics of repeated sickness absence. The records of medically certified and uncertified sickness absence of all 769 telegraphists continuously employed in all State capitals over a two-and-a-half-year period were compared with those of 411 clerks and 415 mechanics and, in Sydney, 380 mail sorters and 80 of their supervisors. All telegraphists in Sydney, Melbourne, and Brisbane, and all mail sorters in Sydney, who were available and willing were later medically examined. From their absence pattern repeaters (employees who had had eight or more certified absences in two and a half years) were separated into three types based on a presumptive origin in chance, recurrent disease and symptomatic non-specific disorder. The observed distribution of individual frequency of certified absence over the full two-and-a-half-year period of study followed that expected from the univariate negative binomial, using maximum likelihood estimators, rather than the poisson distribution, in three of the four occupational groups in Sydney. Limited correlational and bivariate analysis supported the interpretation of proneness ascribed to the univariate fit. In the two groups studied, frequency of uncertified absence could not be fitted by the negative binomial, although the numbers of

  1. Do gamma-ray burst sources repeat?

    NASA Technical Reports Server (NTRS)

    Meegan, Charles A.; Hartmann, Dieter H.; Brainerd, J. J.; Briggs, Michael S.; Paciesas, William S.; Pendleton, Geoffrey; Kouveliotou, Chryssa; Fishman, Gerald; Blumenthal, George; Brock, Martin

    1995-01-01

    The demonstration of repeated gamma-ray bursts from an individual source would severely constrain burst source models. Recent reports (Quashnock and Lamb, 1993; Wang and Lingenfelter, 1993) of evidence for repetition in the first BATSE burst catalog have generated renewed interest in this issue. Here, we analyze the angular distribution of 585 bursts of the second BATSE catalog (Meegan et al., 1994). We search for evidence of burst recurrence using the nearest and farthest neighbor statistic and the two-point angular correlation function. We find the data to be consistent with the hypothesis that burst sources do not repeat; however, a repeater fraction of up to about 20% of the observed bursts cannot be excluded.

  2. Localization of thoracic duct using heavily T2W MRI for intractable post-esophagectomy chylothorax—a case report

    PubMed Central

    Chang, Yi-Chien; Yen, Yi-Ting; Chang, Ming-Chung

    2017-01-01

    Post-esophagectomy chylothorax is a rare yet serious complication. Herein we report the case of a patient with intractable post-esophagectomy chylothorax despite medical treatment with total parenteral nutrition and octreotide, as well as prophylactic and repeated thoracic duct mass ligation. The patient was eventually treated with localization of thoracic duct using T2-weighted magnetic resonance imaging (T2W MRI), followed by video-assisted thoracoscopic thoracic duct ligation. PMID:28275492

  3. Formation of the Arabidopsis pentatricopeptide repeat family.

    PubMed

    Rivals, Eric; Bruyère, Clémence; Toffano-Nioche, Claire; Lecharny, Alain

    2006-07-01

    In Arabidopsis (Arabidopsis thaliana) the 466 pentatricopeptide repeat (PPR) proteins are putative RNA-binding proteins with essential roles in organelles. Roughly half of the PPR proteins form the plant combinatorial and modular protein (PCMP) subfamily, which is land-plant specific. PCMPs exhibit a large and variable tandem repeat of a standard pattern of three PPR variant motifs. The association or not of this repeat with three non-PPR motifs at their C terminus defines four distinct classes of PCMPs. The highly structured arrangement of these motifs and the similar repartition of these arrangements in the four classes suggest precise relationships between motif organization and substrate specificity. This study is an attempt to reconstruct an evolutionary scenario of the PCMP family. We developed an innovative approach based on comparisons of the proteins at two levels: namely the succession of motifs along the protein and the amino acid sequence of the motifs. It enabled us to infer evolutionary relationships between proteins as well as between the inter- and intraprotein repeats. First, we observed a polarized elongation of the repeat from the C terminus toward the N-terminal region, suggesting local recombinations of motifs. Second, the most N-terminal PPR triple motif proved to evolve under different constraints than the remaining repeat. Altogether, the evidence indicates different evolution for the PPR region and the C-terminal one in PCMPs, which points to distinct functions for these regions. Moreover, local sequence homogeneity observed across PCMP classes may be due to interclass shuffling of motifs, or to deletions/insertions of non-PPR motifs at the C terminus.

  4. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    SciTech Connect

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  5. The puzzle of the triple repeats

    SciTech Connect

    Morell, V.

    1993-06-04

    Two years ago, when researchers discovered the gene that causes a hereditary form of mental retardation known as fragile-X syndrome, they also turned up a mutation so unexpected geneticists are still scratching their heads over it. The defect, which makes genes balloon in size by adding extra copies of a three base-pair repeated sequence of DNA, was the first of its kind. Despite decades of study, nothing like it had ever been seen in any of the species that laid the foundations for modern genetics: bacteria, the fruit fly Drosophila melanogaster, and the mouse. The mutations caused by these expanding trinucleotide repeats turned out be common causes of human disease. In the past 2 years, they have been fingered as the culprits in three hereditary disorders besides fragile-X syndrome: myotronic dystrophy, spinobullar muscular atrophy (also known as Kennedy's disease), and just this March-Huntington's disease. The FMR-1 gene, which is the one at fault in fragile-X syndrome, shows just how much the trinucleotide repeats can expand. The normal gene carries at most 50 copies of the CGG trinucleotide. But in children who inherit the gene from these carriers and actually develop mental retardation and the other fragile-X symptoms, the FMR-1 gene may have hundreds to thousands of CGG repeats. Huge expansions of another trinucleotide repeat (CTG) can also occur from one generation to the next in the gene that causes myotonic dystrophy (DM), while smaller, although no less devastating, expansions in the CAG trinucleotide repeat lead to Huntington's and Kennedy's diseases.

  6. Safety of Repeated Yttrium-90 Radioembolization

    SciTech Connect

    Lam, Marnix G. E. H.; Louie, John D.; Iagaru, Andrei H.; Goris, Michael L.; Sze, Daniel Y.

    2013-10-15

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

  7. MRI of neuronal plasticity in rodent models.

    PubMed

    Pelled, Galit

    2011-01-01

    Modifications in the behavior and architecture of neuronal networks are well documented to occur in association with learning and memory, as well as following injury. These plasticity mechanisms are crucial to ensure adequate processing of stimuli, and they also dictate the degree of recovery following peripheral or central nervous system injury. Nevertheless, the underlying neuronal mechanisms that determine the degree of plasticity of neuronal pathways are not fully understood. Recent developments in animal-dedicated magnetic resonance imaging (MRI) scanners and related hardware afford a high spatial and temporal resolution, making functional MRI and manganese-enhanced MRI emerging tools for studying reorganization of neuronal pathways in rodent models. Many of the observed changes in neuronal functions in rodent's brains following injury discussed here agree with clinical human fMRI findings. This demonstrates that animal model imaging can have a significant clinical impact in the neuronal plasticity and rehabilitation arenas.

  8. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    MedlinePlus

    ... cause a problem near a strong magnetic field. Electronic devices aren't permitted in the MRI room. ... child may be given headphones to listen to music or earplugs to block the noise, and will ...

  9. Magnetic Resonance Imaging (MRI) (For Parents)

    MedlinePlus

    ... such as eyeglasses, jewelry, belts, or credit cards. Electronic devices are not permitted in the MRI room. ... child may be given headphones to listen to music or earplugs to block the noise and will ...

  10. MRI of the Body (Chest, Abdomen, Pelvis)

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  11. Ultrasound- and MRI-Guided Prostate Biopsy

    MedlinePlus

    ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ... of the body being imaged, send and receive radio waves, producing signals that are detected by the coils. ...

  12. Magnetic Resonance Imaging (MRI): Dynamic Pelvic Floor

    MedlinePlus

    ... noninvasive test that uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  13. Functional lung imaging using hyperpolarized gas MRI.

    PubMed

    Fain, Sean B; Korosec, Frank R; Holmes, James H; O'Halloran, Rafael; Sorkness, Ronald L; Grist, Thomas M

    2007-05-01

    The noninvasive assessment of lung function using imaging is increasingly of interest for the study of lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma. Hyperpolarized gas MRI (HP MRI) has demonstrated the ability to detect changes in ventilation, perfusion, and lung microstructure that appear to be associated with both normal lung development and disease progression. The physical characteristics of HP gases and their application to MRI are presented with an emphasis on current applications. Clinical investigations using HP MRI to study asthma, COPD, cystic fibrosis, pediatric chronic lung disease, and lung transplant are reviewed. Recent advances in polarization, pulse sequence development for imaging with Xe-129, and prototype low magnetic field systems dedicated to lung imaging are highlighted as areas of future development for this rapidly evolving technology.

  14. SU-D-18C-01: A Novel 4D-MRI Technology Based On K-Space Retrospective Sorting

    SciTech Connect

    Liu, Y; Yin, F; Cai, J

    2014-06-01

    Purpose: Current 4D-MRI techniques lack sufficient temporal/spatial resolution and consistent tumor contrast. To overcome these limitations, this study presents the development and initial evaluation of an entirely new framework of 4D-MRI based on k-space retrospective sorting. Methods: An important challenge of the proposed technique is to determine the number of repeated scans(NR) required to obtain sufficient k-space data for 4D-MRI. To do that, simulations using 29 cancer patients' respiratory profiles were performed to derive the relationship between data acquisition completeness(Cp) and NR, also relationship between NR(Cp=95%) and the following factors: total slice(NS), respiratory phase bin length(Lb), frame rate(fr), resolution(R) and image acquisition starting-phase(P0). To evaluate our technique, a computer simulation study on a 4D digital human phantom (XCAT) were conducted with regular breathing (fr=0.5Hz; R=256×256). A 2D echo planer imaging(EPI) MRI sequence were assumed to acquire raw k-space data, with respiratory signal and acquisition time for each k-space data line recorded simultaneously. K-space data was re-sorted based on respiratory phases. To evaluate 4D-MRI image quality, tumor trajectories were measured and compared with the input signal. Mean relative amplitude difference(D) and cross-correlation coefficient(CC) are calculated. Finally, phase-sharing sliding window technique was applied to investigate the feasibility of generating ultra-fast 4D-MRI. Result: Cp increased with NR(Cp=100*[1-exp(-0.19*NR)], when NS=30, Lb=100%/6). NR(Cp=95%) was inversely-proportional to Lb (r=0.97), but independent of other factors. 4D-MRI on XCAT demonstrated highly accurate motion information (D=0.67%, CC=0.996) with much less artifacts than those on image-based sorting 4D-MRI. Ultra-fast 4D-MRI with an apparent temporal resolution of 10 frames/second was reconstructed using the phase-sharing sliding window technique. Conclusions: A novel 4D-MRI

  15. MRI volumetry of prefrontal cortex

    NASA Astrophysics Data System (ADS)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  16. Therapeutics development for triplet repeat expansion diseases.

    PubMed

    Di Prospero, Nicholas A; Fischbeck, Kenneth H

    2005-10-01

    The underlying genetic mutations for many inherited neurodegenerative disorders have been identified in recent years. One frequent type of mutation is trinucleotide repeat expansion. Depending on the location of the repeat expansion, the mutation might result in a loss of function of the disease gene, a toxic gain of function or both. Disease gene identification has led to the development of model systems for investigating disease mechanisms and evaluating treatments. Examination of experimental findings reveals similarities in disease mechanisms as well as possibilities for treatment.

  17. Evaluation of high-resolution In Vivo MRI for longitudinal analysis of endochondral fracture healing in mice

    PubMed Central

    Müller-Graf, Fabian; Matthys, Romano; Hägele, Yvonne; Fischer, Verena; Jonas, René; Abaei, Alireza; Gebhard, Florian; Rasche, Volker; Ignatius, Anita

    2017-01-01

    Mice are extensively used for experimental bone-healing studies. However, there are few established nondestructive in vivo techniques for longitudinal fracture-healing analysis in mice, including in vivo micro-computed tomography (μCT) and radiography. Importantly, none of the established methods can discriminate between non-mineralized fibrous tissue and cartilage in the soft fracture callus. Therefore, the objective was to establish high-resolution in vivo magnetic resonance imaging (MRI) for the longitudinal assessment of soft callus formation during bone healing in mice. C57BL/6J mice received a femur osteotomy stabilized using an external fixator and were randomly assigned to five groups. Group 1 mice were scanned three times longitudinally during fracture healing using an optimized MRI scanning protocol to establish an algorithm to characterize the different fracture-callus tissues. Mice of groups 2–4 were scanned once on day 10, 14 or 21, respectively, euthanized after scanning and their femurs subjected to ex vivo μCT and histomorphometric analysis to compare the data assessed by MRI with μCT and histology. Control group 5 mice were not scanned. After 28 days, mice of groups 1 and 5 were euthanized and the fracture-healing outcome was evaluated by bending-test, μCT and histology to determine whether the repeated anesthesia, handling and the MRI measurements themselves influenced fracture healing. The callus-tissue values determined by MRI were mostly comparable to those obtained by μCT and histomorphometric analysis. However, at time points characterized by small relative bone or cartilage areas, MRI measurements were weakly comparable to histomorphometric data, possibly due to the inferior spatial resolution. Importantly, at the early and intermediate phases of healing, cartilage and fibrous-tissue values obtained by MRI were highly accurate. Furthermore, repeated anesthesia, handling and MRI scans did not impact bone healing. Therefore, we

  18. Gray matter myelination of 1555 human brains using partial volume corrected MRI images

    PubMed Central

    Shafee, Rebecca; Buckner, Randy L.; Fischl, Bruce

    2014-01-01

    The myelin content of the cortex changes over the human lifetime and aberrant cortical myelination is associated with diseases such as schizophrenia and multiple sclerosis. Recently magnetic resonance imaging (MRI) techniques have shown potential in differentiating between myeloarchitectonically distinct cortical regions in vivo. Here we introduce a new algorithm for correcting partial volume effects present in mm-scale MRI images which was used to investigate the myelination pattern of the cerebral cortex in 1555 clinically normal subjects using the ratio of T1-weighted (T1w) and T2-weighted (T2w) MRI images. A significant linear cross-sectional age increase in T1w/T2w estimated myelin was detected across an 18 to 35 year age span (highest value of ~ 1%/year compared to mean T1w/T2w myelin value at 18 years). The cortex was divided at mid-thickness and the value of T1w/T2w myelin calculated for the inner and the outer layers separately. The increase in T1w/T2w estimated myelin occurs predominantly in the inner layer for most cortical regions. The ratio of the inner and outer layer T1w/T12w myelin was further validated using high-resolution in vivo MRI scans and also a high-resolution MRI scan of a postmortem brain. Additionally, the relationships between cortical thickness, curvature and T1w/T2w estimated myelin were found to be significant, although the relationships varied across the cortex. We discuss these observations as well as limitations of using the T1w/T2w ratio as an estimate of cortical myelin. PMID:25449739

  19. Recent Advances in MRI of Articular Cartilage

    PubMed Central

    Gold, Garry E.; Chen, Christina A.; Koo, Seungbum; Hargreaves, Brian A.; Bangerter, Neal K.

    2010-01-01

    OBJECTIVE MRI is the most accurate noninvasive method available to diagnose disorders of articular cartilage. Conventional 2D and 3D approaches show changes in cartilage morphology. Faster 3D imaging methods with isotropic resolution can be reformatted into arbitrary planes for improved detection and visualization of pathology. Unique contrast mechanisms allow us to probe cartilage physiology and detect changes in cartilage macromolecules. CONCLUSION MRI has great promise as a noninvasive comprehensive tool for cartilage evaluation. PMID:19696274

  20. MRI-powered Actuators for Robotic Interventions

    PubMed Central

    Vartholomeos, Panagiotis; Qin, Lei; Dupont, Pierre E.

    2012-01-01

    This paper presents a novel actuation technology for robotically assisted MRI-guided interventional procedures. Compact and wireless, the actuators are both powered and controlled by the MRI scanner. The design concept and performance limits are described and derived analytically. Simulation and experiments in a clinical MR scanner are used to validate the analysis and to demonstrate the capability of the approach for needle biopsies. The concepts of actuator locking mechanisms and multi-axis control are also introduced. PMID:22287082

  1. Effect of Repeated Evaluation and Repeated Exposure on Acceptability Ratings of Sentences

    ERIC Educational Resources Information Center

    Zervakis, Jennifer; Mazuka, Reiko

    2013-01-01

    This study investigated the effect of repeated evaluation and repeated exposure on grammatical acceptability ratings for both acceptable and unacceptable sentence types. In Experiment 1, subjects in the Experimental group rated multiple examples of two ungrammatical sentence types (ungrammatical binding and double object with dative-only verb),…

  2. BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience.

    PubMed

    Yee, J R; Kenkel, W M; Kulkarni, P; Moore, K; Perkeybile, A M; Toddes, S; Amacker, J A; Carter, C S; Ferris, C F

    2016-09-01

    The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological

  3. A fast multiparameter MRI approach for acute stroke assessment on a 3T clinical scanner: preliminary results in a non-human primate model with transient ischemic occlusion

    PubMed Central

    Tong, Frank; Li, Chun-Xia; Yan, Yumei; Nair, Govind; Nagaoka, Tsukasa; Tanaka, Yoji; Zola, Stuart; Howell, Leonard

    2014-01-01

    Many MRI parameters have been explored and demonstrated the capability or potential to evaluate acute stroke injury, providing anatomical, microstructural, functional, or neurochemical information for diagnostic purposes and therapeutic development. However, the application of multiparameter MRI approach is hindered in clinic due to the very limited time window after stroke insult. Parallel imaging technique can accelerate MRI data acquisition dramatically and has been incorporated in modern clinical scanners and increasingly applied for various diagnostic purposes. In the present study, a fast multiparameter MRI approach including structural T1-weighted imaging (T1W), T2-weighted imaging (T2W), diffusion tensor imaging (DTI), T2-mapping, proton magnetic resonance spectroscopy, cerebral blood flow (CBF), and magnetization transfer (MT) imaging, was implemented and optimized for assessing acute stroke injury on a 3T clinical scanner. A macaque model of transient ischemic stroke induced by a minimal interventional approach was utilized for evaluating the multiparameter MRI approach. The preliminary results indicate the surgical procedure successfully induced ischemic occlusion in the cortex and/or subcortex in adult macaque monkeys (n=4). Application of parallel imaging technique substantially reduced the scanning duration of most MRI data acquisitions, allowing for fast and repeated evaluation of acute stroke injury. Hence, the use of the multiparameter MRI approach with up to five quantitative measures can provide significant advantages in preclinical or clinical studies of stroke disease. PMID:24834423

  4. Recollection-related Hippocampal Activity during Continuous Recognition: a High-Resolution fMRI Study

    PubMed Central

    Suzuki, Maki; Johnson, Jeffrey D.; Rugg, Michael D.

    2010-01-01

    We used high-resolution functional magnetic resonance imaging (fMRI) to investigate whether successful recollection during continuous recognition is associated with relative enhancement of hippocampal activity, consistent with prior findings from experiments employing separate study and test phases. While being scanned, subjects discriminated between new and repeated pictures. Each picture, which was repeated once after an interval of between 10 and 30 items, was surrounded by a frame that was colored grey, blue, or orange. When an item repeated, its frame color determined the correct response. Repeated items surrounded by a grey frame always required an ‘old’ judgment. A repeated item surrounded by a blue or an orange frame required a different response depending whether it was re-presented in the same (Target) or a different (Nontarget) color from the first presentation. Consistent with the results from previous continuous recognition experiments, robust new > old effects were found in bilateral hippocampus. Additionally, an across-subjects correlational analysis identified a cluster of voxels in right hippocampus where recollection-related activity (operationalized by the contrast between correctly vs. incorrectly judged Nontargets) was positively correlated with recollection performance. Thus, successful recollection during continuous recognition is associated with a relative enhancement of hippocampal activity. PMID:20232398

  5. The PRESTO technique for fMRI

    PubMed Central

    van Gelderen, P.; Duyn, J.H.; Ramsey, N.F.; Liu, G.; Moonen, C.T.W.

    2012-01-01

    In the early days of BOLD fMRI, the acquisition of T2* weighted data was greatly facilitated by rapid scan techniques such as EPI. The latter, however, was only available on a few MRI systems that were equipped with specialized hardware that allowed rapid switching of the imaging gradients. For this reason, soon after the invention of fMRI, the scan technique PRESTO was developed to make rapid T2* weighted scanning available on standard clinical scanning. This method combined echo shifting, which allows for echo times longer than the sequence repetition time, with acquisition of multiple k-space lines per excitation. These two concepts were combined in order to achieve a method fast enough for fMRI, while maintaining a sufficiently long echo time for optimal contrast. PRESTO has been primarily used for 3D scanning, which minimized the contribution of large vessels due to inflow effects. Although PRESTO is still being used today, its appeal has lessened somewhat due to increased gradient performance of modern MRI scanners. Compared to 2D EPI, PRESTO may have somewhat reduced temporal stability, which is a disadvantage for fMRI that may not outweigh the advantage of reduced inflow effects provided by 3D scanning. In this overview, the history of the development of the PRESTO is presented, followed by a qualitative comparison with EPI. PMID:22245350

  6. Emerging MRI methods in rheumatoid arthritis.

    PubMed

    Borrero, Camilo G; Mountz, James M; Mountz, John D

    2011-02-01

    New MRI techniques have been developed to assess not only the static anatomy of synovial hyperplasia, bone changes and cartilage degradation in patients with rheumatoid arthritis (RA), but also the activity of the physiological events that cause these changes. This enables an estimation of the rate of change in the synovium, bone and cartilage as a result of disease activity or in response to therapy. Typical MRI signs of RA in the pre-erosive phase include synovitis, bone marrow edema and subchondral cyst formation. Synovitis can be assessed by T2-weighted imaging, dynamic contrast-enhanced MRI or diffusion tensor imaging. Bone marrow edema can be detected on fluid-sensitive sequences such as short-tau inversion recovery or T2-weighted fast-spin echo sequences. Detection of small bone erosions in the early erosive phase using T1-weighted MRI has sensitivity comparable to CT. Numerous MRI techniques have been developed for quantitative assessment of potentially pathologic changes in cartilage composition that occur before frank morphologic changes. In this Review, we summarize the advances and new directions in the field of MRI, with an emphasis on their current state of development and application in RA.

  7. Diffusion MRI and its role in neuropsychology

    PubMed Central

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-01-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain’s white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition. PMID:26255305

  8. Diffusion MRI and its Role in Neuropsychology.

    PubMed

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-09-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain's white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition.

  9. Advanced flow MRI: emerging techniques and applications.

    PubMed

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented.

  10. Toward correlating functional MRI and EEG sources

    NASA Astrophysics Data System (ADS)

    Singh, Manbir; Khosla, Deepak

    1996-04-01

    Though excellent spatial resolution (on the order of 1 mm) is obtainable in functional MRI (fMRI), its temporal resolution is limited to about 1 second by hemodynamics. On the other hand, magnetoencephalography (MEG) and electroencephalography (EEG) provide millisecond temporal resolution but a relatively crude (on the order of 1 cm) spatial resolution to localized sources. Thus, techniques that could combine the high temporal resolution of MEG or EEG with the high spatial resolution of fMRI would be of great significance in imaging the spatiotemporal distribution of neuronal activation. With the ultimate objective of combining fMRI and EEG activation studies, we have conducted experiments to determine how pixels activated in fMRI correlate with underlying EEG sources in a given subject during visual stimulation. Results of a three-subject study suggest good correlation between the center-of-gravity of activated pixels seen in fMRI and the center-of-gravity of regions localized through EEG measurements.

  11. MRI atlas of the brain

    SciTech Connect

    Bradley, W.G. ); Bydder, G. )

    1990-01-01

    Since most radiologists will start from a basic of familiarity with pathophysiology of disease and a knowledge of cross-sectional imaging (at least in the transaxial plane), they are in a good position to recognize and diagnose many of the abnormalities we can currently see with CT. The appearance of these lesions on MRI is the basis for the majority of the images in this book. Chapters on Tumors, Infarcts and Ischemia, Demyelination and Infection. Hydrocephalus, and Pediatrics feature multiple images displaying the MR appearance of many common lesions with minimal associated text. Instead of focusing on pathophysiology, attention is directed to the variable appearance of these disease states using various MR imaging techniques. Although the MR contrast agent, Gadolinium-DTPA, has similar behavior (physiologically) to meglumine diatrizoate in CT, the MR techniques which result in optimal visualization of enhancing lesions are nonintuitive and are discussed. Similarly, the appearance of flowing blood and CSF and hemorrhage does not follow easily from a pre-existing CT base, therefore additional text has been devoted to these subjects.

  12. Gradient-Modulated PETRA MRI.

    PubMed

    Kobayashi, Naoharu; Goerke, Ute; Wang, Luning; Ellermann, Jutta; Metzger, Gregory J; Garwood, Michael

    2015-12-01

    Image blurring due to off-resonance and fast T 2(*) signal decay is a common issue in radial ultrashort echo time MRI sequences. One solution is to use a higher readout bandwidth, but this may be impractical for some techniques like pointwise encoding time reduction with radial acquisition (PETRA), which is a hybrid method of zero echo time and single point imaging techniques. Specifically, PETRA has severe specific absorption rate (SAR) and radiofrequency (RF) pulse peak power limitations when using higher bandwidths in human measurements. In this study, we introduce gradient modulation (GM) to PETRA to reduce image blurring artifacts while keeping SAR and RF peak power low. Tolerance of GM-PETRA to image blurring was evaluated in simulations and experiments by comparing with the conventional PETRA technique. We performed inner ear imaging of a healthy subject at 7T. GM-PETRA showed significantly less image blurring due to off-resonance and fast T2(*) signal decay compared to PETRA. In in vivo imaging, GM-PETRA nicely captured complex structures of the inner ear such as the cochlea and semicircular canals. Gradient modulation can improve the PETRA image quality and mitigate SAR and RF peak power limitations without special hardware modification in clinical scanners.

  13. AGG interspersions within the FMR1 CGG repeat: Mechanisms and models of triplet repeat instability

    SciTech Connect

    Eichler, E.E.; Nelson, D.L.

    1994-09-01

    Fragile X syndrome CGG repeat alleles are typically classified as normal, premutation, or full mutation based on the length of the repeat in the 5{prime} UTR of the FMR1 gene. The distinction between high-end normals and low-end premutation alleles, however, is not always clear since repeats of similar size differ markedly in their intergenerational stability. This fact suggest that differences in sequence content may play a key role in determining an allele`s predisposition to instability. It has been postulated that the loss of AGG interruptions within the CGG tract may trigger this instability. To test this model, we have developed a simple indirect method to determine the presence or absence of internal AGGs within the FMR1 CGG repeat tract. Analysis of 84 human X chromosomes for the presence of interrupting AGG trinucleotides revealed that most alleles possess two interspersed AGGs at a periodicity of 9 or 10 CGGs. The longest tract of uninterrupted CGG repeats is usually found at the 3{prime} end indicating that variation in the length of the repeat is polar. Alleles containing between 34 and 55 repeats, with documented unstable transmissions, were shown to have lost one or both AGG interruptions when compared to stable alleles of similar length. These comparisons define an instability threshold between 34 and 38 uninterrupted CGG repeats. Analysis of premutation alleles in fragile X syndrome carriers reveals that 70% of these alleles contain a single AGG interruption. Population studies confirm that such highly punctuated FMR1 CGG repeats are virtually static in terms of length variation. These data suggest that the loss of an AGG is an important mutational event in the generation of unstable alleles predisposed to the fragile X syndrome. Loss of AGG trinucleotides and polarized variability support Okazaki fragment slippage as a model for CGG repeat instability and hyperexpansion.

  14. Structures of designed armadillo-repeat proteins show propagation of inter-repeat interface effects

    PubMed Central

    Reichen, Christian; Madhurantakam, Chaithanya; Hansen, Simon; Grütter, Markus G.; Plückthun, Andreas; Mittl, Peer R. E.

    2016-01-01

    The armadillo repeat serves as a scaffold for the development of modular peptide-recognition modules. In order to develop such a system, three crystal structures of designed armadillo-repeat proteins with third-generation N-caps (YIII-type), four or five internal repeats (M-type) and second-generation C-caps (AII-type) were determined at 1.8 Å (His-YIIIM4AII), 2.0 Å (His-YIIIM5AII) and 1.95 Å (YIIIM5AII) resolution and compared with those of variants with third-generation C-caps. All constructs are full consensus designs in which the internal repeats have exactly the same sequence, and hence identical conformations of the internal repeats are expected. The N-cap and internal repeats M1 to M3 are indeed extremely similar, but the comparison reveals structural differences in internal repeats M4 and M5 and the C-cap. These differences are caused by long-range effects of the C-cap, contacting molecules in the crystal, and the intrinsic design of the repeat. Unfortunately, the rigid-body movement of the C-terminal part impairs the regular arrangement of internal repeats that forms the putative peptide-binding site. The second-generation C-cap improves the packing of buried residues and thereby the stability of the protein. These considerations are useful for future improvements of an armadillo-repeat-based peptide-recognition system. PMID:26894544

  15. Epigenetic Analysis of Neurocognitive Development at 1 year of Age in a Community-Based Pregnancy Cohort

    PubMed Central

    Murphy, Laura E.; Palmer, Frederick B.; Graff, J. Carolyn; Sutter, Thomas R.; Mozhui, Khyobeni; Hovinga, Collin A.; Thomas, Fridtjof; Park, Vicki; Tylavsky, Frances A.; Adkins, Ronald M.

    2014-01-01

    Multiple studies show that molecular genetic changes and epigenetic modifications affect the risk of cognitive disability or impairment. However, the role of epigenetic variation in cognitive development of neurotypical young children remains largely unknown. Using data from a prospective, community-based study of mother-infant pairs, we investigated the association of DNA methylation patterns in neonatal umbilical cord blood with cognitive and language development at 1 year of age. No CpG loci achieved genome-wide significance, although a small number of weakly suggestive associations with Bayley-III Receptive Communication scales were noted. While umbilical cord blood is a convenient resource for genetic analyses of birth outcomes, our results do not provide conclusive evidence that its use for DNA methylation profiling yields epigenetic markers that are directly related to postnatal neurocognitive outcomes at 1 year of age. PMID:24452678

  16. Triggering of repeating earthquakes in central California

    USGS Publications Warehouse

    Wu, Chunquan; Gomberg, Joan; Ben-Naim, Eli; Johnson, Paul

    2014-01-01

    Dynamic stresses carried by transient seismic waves have been found capable of triggering earthquakes instantly in various tectonic settings. Delayed triggering may be even more common, but the mechanisms are not well understood. Catalogs of repeating earthquakes, earthquakes that recur repeatedly at the same location, provide ideal data sets to test the effects of transient dynamic perturbations on the timing of earthquake occurrence. Here we employ a catalog of 165 families containing ~2500 total repeating earthquakes to test whether dynamic perturbations from local, regional, and teleseismic earthquakes change recurrence intervals. The distance to the earthquake generating the perturbing waves is a proxy for the relative potential contributions of static and dynamic deformations, because static deformations decay more rapidly with distance. Clear changes followed the nearby 2004 Mw6 Parkfield earthquake, so we study only repeaters prior to its origin time. We apply a Monte Carlo approach to compare the observed number of shortened recurrence intervals following dynamic perturbations with the distribution of this number estimated for randomized perturbation times. We examine the comparison for a series of dynamic stress peak amplitude and distance thresholds. The results suggest a weak correlation between dynamic perturbations in excess of ~20 kPa and shortened recurrence intervals, for both nearby and remote perturbations.

  17. Chlorinated hydrocarbons in women with repeated miscarriages.

    PubMed Central

    Gerhard, I; Daniel, V; Link, S; Monga, B; Runnebaum, B

    1998-01-01

    This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations between 1989 and 1993, and compared to a previously investigated reference population. In more than 20% of the women, at least one of the CHC levels exceeded the reference range. CHC levels did not differ significantly between women with primary or secondary and early or late miscarriages; neither did they differ between women with hormonal or immunological disorders as causes of repeated miscarriages or women with idiopathic repeated miscarriages. No significant associations were detected between CHC levels and further conceptions or the outcome of further pregnancies. As significant associations were found between increasing CHC blood concentrations and immunological and hormonal changes, CHCs may have an impact on the pregnancy course in certain cases. PMID:9755145

  18. Is Retrieval Mediated after Repeated Testing?

    ERIC Educational Resources Information Center

    Kole, James A.; Healy, Alice F.

    2013-01-01

    In 2 main experiments, the mediated priming effect was used to determine whether retrieval continues to be mediated after repeated testing. In each experiment, participants used the keyword method to learn French vocabulary, then completed a modified lexical decision task in which they first translated a French word, and then made a lexical…

  19. Repeater For A Digital-Communication Bus

    NASA Technical Reports Server (NTRS)

    Torres-Guzman, Esteban; Olson, Stephen; Heaps, Tim

    1993-01-01

    Digital repeater circuit designed to extend range of communication on MIL-STD-1553 bus beyond original maximum allowable length of 300 ft. Circuit provides two-way communication, one way at time, and conforms to specifications of MIL-STD-1553. Crosstalk and instability eliminated.

  20. Rectourethral fistula after repeat transrectal prostate biopsy.

    PubMed

    Loran, Oleg B; Veliev, Evgeny I; Sokolov, Egor A; Dadashev, Elmar O; Guspanov, Renat I

    2013-09-01

    Transrectal prostate biopsy is considered a relatively safe procedure, with a quite small number of complications. We report a patient with a rectourethral fistula after a repeat transrectal prostate biopsy. To our knowledge, this is the first incident in the published literature.

  1. Repeated Random Sampling in Year 5

    ERIC Educational Resources Information Center

    Watson, Jane M.; English, Lyn D.

    2016-01-01

    As an extension to an activity introducing Year 5 students to the practice of statistics, the software "TinkerPlots" made it possible to collect repeated random samples from a finite population to informally explore students' capacity to begin reasoning with a distribution of sample statistics. This article provides background for the…

  2. [Preventive maintenance of repeated ischemic insults].

    PubMed

    Gavrilenko, A V; Kuklin, A V; Kravchenko, A A; Agafonov, I N

    2008-01-01

    In the review we offer analysis of the effectiveness of carotid endarterectomy in treatment of post-functional apoplexy or stroke patients. Published results of the researches specify possible efficiency of carotid endarterectomy in preventive maintenance against repeated apoplectic attack or strokes. Yet the criteria of usage and execution of the carotid endarterectomy are still to be discussed.

  3. Epigenetics and Triplet-Repeat Neurological Diseases

    PubMed Central

    Nageshwaran, Sathiji; Festenstein, Richard

    2015-01-01

    The term “junk DNA” has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterochromatinized resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, with several genes known to require such an environment to permit transcription. Repetitive regions frequently exist as dinucleotide, trinucleotide, and tetranucleotide repeats. The association between repetitive regions and disease was emphasized following the discovery of abnormal trinucleotide repeats underlying spinal and bulbar muscular atrophy (Kennedy’s disease) and fragile X syndrome of mental retardation (FRAXA) in 1991. In this review, we provide a brief overview of epigenetic mechanisms and then focus on several diseases caused by DNA triplet-repeat expansions, which exhibit diverse epigenetic effects. It is clear that the emerging field of epigenetics is already generating novel potential therapeutic avenues for this group of largely incurable diseases. PMID:26733936

  4. Testing Multiple Outcomes in Repeated Measures Designs

    ERIC Educational Resources Information Center

    Lix, Lisa M.; Sajobi, Tolulope

    2010-01-01

    This study investigates procedures for controlling the familywise error rate (FWR) when testing hypotheses about multiple, correlated outcome variables in repeated measures (RM) designs. A content analysis of RM research articles published in 4 psychology journals revealed that 3 quarters of studies tested hypotheses about 2 or more outcome…

  5. Y Se Repite = And It Repeats Itself

    ERIC Educational Resources Information Center

    Katzew, Adriana

    2010-01-01

    In this article, the author discusses Y Se Repite [And It Repeats Itself], a project she conceptualized due to the growing number of Latino/a Mexican migrant workers in dairy farms in the state of Vermont. In 2006, approximately 2,000 Latinos/as--most of them undocumented Mexican migrant workers--worked throughout the state's dairy farms, yet…

  6. Longer-baseline telescopes using quantum repeaters.

    PubMed

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2012-08-17

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines.

  7. The Effect of Repeaters on Equating

    ERIC Educational Resources Information Center

    Kim, HeeKyoung; Kolen, Michael J.

    2010-01-01

    Test equating might be affected by including in the equating analyses examinees who have taken the test previously. This study evaluated the effect of including such repeaters on Medical College Admission Test (MCAT) equating using a population invariance approach. Three-parameter logistic (3-PL) item response theory (IRT) true score and…

  8. Cognitive functions over the course of 1 year in multiple sclerosis patients treated with disease modifying therapies

    PubMed Central

    Utz, Kathrin S.; Lee, De-Hyung; Lämmer, Alexandra; Waschbisch, Anne; Linker, Ralf A.; Schenk, Thomas

    2016-01-01

    Objectives: Disease-modifying therapies (DMTs) are applied to delay or prevent disease progression in multiple sclerosis (MS). While this has mostly been proven for physical symptoms, available studies regarding long-term effects of DMTs on cognitive functions are rare and sometimes inconsistent due to methodological shortcomings. Particularly in the case of fingolimod, comprehensive data on cognitive functions are not yet available. Therefore, we set out to reliably assess cognitive functions in patients with relapsing–remitting MS (RRMS) treated with DMTs over 1 year. Methods: Cognitive functions were assessed with eight tests at three timepoints: baseline, 6-month follow up and 12-month follow up. First, we investigated whether the stability of cognitive functions (i.e. not falling below the 5% cut-off in more than one test) over 1 year in RRMS patients (n = 41) corresponds to the stability in healthy individuals (n = 40) of a previous study. Second, we compared the percentage of declined and improved patients in the different tests. Third, we compared patients treated with fingolimod (n = 22) with patients treated with natalizumab (n = 11) with regard to cognitive stability. Fourth, based on the patient data, the Reliable Change Index was applied to compute cut-offs for reliable cognitive change. Results: Approximately 75% of RRMS patients treated with DMTs remained stable over the course of 1 year. The Paced Auditory Serial Addition Test (PASAT) and the Spatial Recall Test (SPART), produced improvements in 12.5% and 30.6%, respectively, probably due to practice effects. Patients treated with fingolimod did not differ from patients treated with natalizumab with regard to cognitive stability. Conclusions: Cognitive functions remain relatively stable under DMT treatment over 1 year, irrespective of the type of medication. Furthermore, the tests PASAT and SPART should be interpreted cautiously in studies examining performance changes over time. The provided RCI

  9. Prevalence, Course, Incidence, and 1-Year Prediction of Deliberate Self-Harm and Suicide Attempts in Early Norwegian School Adolescents

    ERIC Educational Resources Information Center

    Larsson, Bo; Sund, Anne Mari

    2008-01-01

    In this survey of early Norwegian school adolescents, the prevalence, course, and incidence of self-harm behavior with or without suicide intent were examined, in addition to predictors of self-harm for a 1-year follow-up period. Lifetime prevalence rates of self-harm without suicide intent and suicide attempts were 2.9% and 3.0%, respectively,…

  10. Effectiveness of MR Angiography for the Primary Diagnosis of Acute Pulmonary Embolism: Clinical Outcomes at 3 Months and 1 Year

    PubMed Central

    Schiebler, Mark L.; Nagle, Scott K.; François, Christopher J.; Repplinger, Michael D.; Hamedani, Azita G.; Vigen, Karl K.; Yarlagadda, Rajkumar; Grist, Thomas M.; Reeder, Scott B.

    2014-01-01

    Purpose To determine the effectiveness of MR angiography for pulmonary embolism (MRA-PE) in symptomatic patients. Materials and Methods We retrospectively reviewed all patients whom were evaluated for possible pulmonary embolism (PE) using MRA-PE. A 3-month and 1-year from MRA-PE electronic medical record (EMR) review was performed. Evidence for venous thromboembolism (VTE) (or death from PE) within the year of follow-up was the outcome surrogate for this study. Results There were 190 MRA-PE exams performed with 97.4% (185/190) of diagnostic quality. There were 148 patients (120 F: 28 M) that had both a diagnostic MRA-PE exam and 1 complete year of EMR follow-up. There were 167 patients (137 F: 30 M) with 3 months or greater follow-up. We found 83% (139/167) and 81% (120/148) MRA-PE exams negative for PE at 3 months and 1 year, respectively. Positive exams for PE were seen in 14% (23/167). During the 1-year follow-up period, five patients (false negative) were diagnosed with DVT (5/148 = 3.4 %), and one of these patients also experienced a non–life-threatening PE. The negative predictive value (NPV) for MRA-PE was 97% (92–99; 95% CI) at 3 months and 96% (90–98; 95% CI) with 1 year of follow-up. Conclusion The NPV of MRA-PE, when used for the primary diagnosis of pulmonary embolism in symptomatic patients, were found to be similar to the published values for CTA-PE. In addition, the technical success rate and safety of MRA-PE were excellent. PMID:23553735

  11. Identifying high-school dance students who will develop an eating disorder: a 1-year prospective study.

    PubMed

    Tseng, Mei-Chih Meg; Fang, David; Chang, Chin-Hao; Lee, Ming-Been

    2013-10-30

    This study examined the changes in eating disorder (ED) status over 1 year and identified risk factors for EDs among female dance students. In 2003, all students enrolled in each of the nation's 12 high schools with gifted dance programs participated in a two-phase survey. The same participants were invited to take part in a follow-up survey 1 year later. In all, 583 persons completed the phase 1 questionnaire survey, and 245 persons completed interviews twice at baseline and follow-up. Thirty-five females had a newly developed ED, and less than half of the ED cases found at baseline had recovered at follow-up. Being a grade 12 student carried a reduced risk of EDs, whereas higher baseline scores on the Bulimic Investigatory Test Edinburgh (BITE) increased risks of developing an ED after 1 year. A 10-item BITE questionnaire validly identified girl dance students who would develop EDs later in high school. EDs were more commonly developed during middle adolescence, and we suggest that prevention work against EDs begin in this period among the dance student population. The brief screening questionnaire might help detect intervention targets of a prevention program among adolescent dance students.

  12. A longitudinal, event-related potential pilot study of adult obsessive-compulsive disorder with 1-year follow-up

    PubMed Central

    Yamamuro, Kazuhiko; Okada, Koji; Kishimoto, Naoko; Ota, Toyosaku; Iida, Junzo; Kishimoto, Toshifumi

    2016-01-01

    Aim Earlier brain imaging research studies have suggested that brain abnormalities in obsessive-compulsive disorder (OCD) normalize as clinical symptoms improve. However, although many studies have investigated event-related potentials (ERPs) in patients with OCD compared with healthy control subjects, it is currently unknown whether ERP changes reflect pharmacological and psychotherapeutic effects. As such, the current study examined the neurocognitive components of OCD to elucidate the pathophysiological abnormalities involved in the disorder, including the frontal-subcortical circuits. Methods The Yale-Brown Obsessive-Compulsive Scale was used to evaluate 14 adult patients with OCD. The present study also included ten age-, sex-, and IQ-matched controls. The P300 and mismatch negativity (MMN) components during an auditory oddball task at baseline for both groups and after 1 year of treatment for patients with OCD were measured. Results Compared with controls, P300 amplitude was attenuated in the OCD group at Cz and C4 at baseline. Pharmacotherapy and psychotherapy treatment for 1 year reduced OCD symptomology. P300 amplitude after 1 year of treatment was significantly increased, indicating normalization compared with baseline at Fz, Cz, C3, and C4. We found no differences in P300 latency, MMN amplitude, or MMN latency between baseline and after one year of treatment. Conclusion ERPs may be a useful tool for evaluating pharmacological and cognitive behavioral therapy in adult patients with OCD. PMID:27713631

  13. "MRI Stealth" robot for prostate interventions.

    PubMed

    Stoianovici, Dan; Song, Danny; Petrisor, Doru; Ursu, Daniel; Mazilu, Dumitru; Muntener, Michael; Mutener, Michael; Schar, Michael; Patriciu, Alexandru

    2007-01-01

    The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low

  14. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    PubMed

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment.

  15. Repeated sprint training in normobaric hypoxia.

    PubMed

    Galvin, Harvey M; Cooke, Karl; Sumners, David P; Mileva, Katya N; Bowtell, Joanna L

    2013-12-01

    Repeated sprint ability (RSA) is a critical success factor for intermittent sport performance. Repeated sprint training has been shown to improve RSA, we hypothesised that hypoxia would augment these training adaptations. Thirty male well-trained academy rugby union and rugby league players (18.4 ± 1.5 years, 1.83 ± 0.07 m, 88.1 ± 8.9 kg) participated in this single-blind repeated sprint training study. Participants completed 12 sessions of repeated sprint training (10 × 6 s, 30 s recovery) over 4 weeks in either hypoxia (13% FiO₂) or normoxia (21% FiO₂). Pretraining and post-training, participants completed sports specific endurance and sprint field tests and a 10 × 6 s RSA test on a non-motorised treadmill while measuring speed, heart rate, capillary blood lactate, muscle and cerebral deoxygenation and respiratory measures. Yo-Yo Intermittent Recovery Level 1 test performance improved after RS training in both groups, but gains were significantly greater in the hypoxic (33 ± 12%) than the normoxic group (14 ± 10%, p<0.05). During the 10 × 6 s RS test there was a tendency for greater increases in oxygen consumption in the hypoxic group (hypoxic 6.9 ± 9%, normoxic (-0.3 ± 8.8%, p=0.06) and reductions in cerebral deoxygenation (% changes for both groups, p=0.09) after hypoxic than normoxic training. Twelve RS training sessions in hypoxia resulted in twofold greater improvements in capacity to perform repeated aerobic high intensity workout than an equivalent normoxic training. Performance gains are evident in the short term (4 weeks), a period similar to a preseason training block.

  16. Repeated sprint training in normobaric hypoxia

    PubMed Central

    Galvin, Harvey M; Cooke, Karl; Sumners, David P; Mileva, Katya N; Bowtell, Joanna L

    2013-01-01

    Repeated sprint ability (RSA) is a critical success factor for intermittent sport performance. Repeated sprint training has been shown to improve RSA, we hypothesised that hypoxia would augment these training adaptations. Thirty male well-trained academy rugby union and rugby league players (18.4±1.5 years, 1.83±0.07 m, 88.1±8.9 kg) participated in this single-blind repeated sprint training study. Participants completed 12 sessions of repeated sprint training (10×6 s, 30 s recovery) over 4 weeks in either hypoxia (13% FiO2) or normoxia (21% FiO2). Pretraining and post-training, participants completed sports specific endurance and sprint field tests and a 10×6 s RSA test on a non-motorised treadmill while measuring speed, heart rate, capillary blood lactate, muscle and cerebral deoxygenation and respiratory measures. Yo-Yo Intermittent Recovery Level 1 test performance improved after RS training in both groups, but gains were significantly greater in the hypoxic (33±12%) than the normoxic group (14±10%, p<0.05). During the 10×6 s RS test there was a tendency for greater increases in oxygen consumption in the hypoxic group (hypoxic 6.9±9%, normoxic (−0.3±8.8%, p=0.06) and reductions in cerebral deoxygenation (% changes for both groups, p=0.09) after hypoxic than normoxic training. Twelve RS training sessions in hypoxia resulted in twofold greater improvements in capacity to perform repeated aerobic high intensity workout than an equivalent normoxic training. Performance gains are evident in the short term (4 weeks), a period similar to a preseason training block. PMID:24282212

  17. Investigations on spinal cord fMRI of cats under ketamine.

    PubMed

    Cohen-Adad, J; Hoge, R D; Leblond, H; Xie, G; Beaudoin, G; Song, A W; Krueger, G; Doyon, J; Benali, H; Rossignol, S

    2009-01-15

    Functional magnetic resonance imaging (fMRI) of the spinal cord has been the subject of intense research for the last ten years. An important motivation for this technique is its ability to detect non-invasively neuronal activity in the spinal cord related to sensorimotor functions in various conditions, such as after spinal cord lesions. Although promising results of spinal cord fMRI have arisen from previous studies, the poor reproducibility of BOLD activations and their characteristics remain a major drawback. In the present study we investigated the reproducibility of BOLD fMRI in the spinal cord of cats (N=9) by repeating the same stimulation protocol over a long period (approximately 2 h). Cats were anaesthetized with ketamine, and spinal cord activity was induced by electrical stimulation of cutaneous nerves of the hind limbs. As a result, task-related signals were detected in most cats with relatively good spatial specificity. However, BOLD response significantly varied within and between cats. This variability was notably attributed to the moderate intensity of the stimulus producing a low amplitude haemodynamic response, variation in end-tidal CO(2) during the session, low signal-to-noise ratio (SNR) in spinal fMRI time series and animal-specific vascular anatomy. Original contributions of the present study are: (i) first spinal fMRI experiment in ketamine-anaesthetized animals, (ii) extensive study of intra- and inter-subject variability of activation, (iii) characterisation of static and temporal SNR in the spinal cord and (iv) investigation on the impact of CO(2) end-tidal level on the amplitude of BOLD response.

  18. RepeatsDB 2.0: improved annotation, classification, search and visualization of repeat protein structures

    PubMed Central

    Paladin, Lisanna; Hirsh, Layla; Piovesan, Damiano; Andrade-Navarro, Miguel A.; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2017-01-01

    RepeatsDB 2.0 (URL: http://repeatsdb.bio.unipd.it/) is an update of the database of annotated tandem repeat protein structures. Repeat proteins are a widespread class of non-globular proteins carrying heterogeneous functions involved in several diseases. Here we provide a new version of RepeatsDB with an improved classification schema including high quality annotations for ∼5400 protein structures. RepeatsDB 2.0 features information on start and end positions for the repeat regions and units for all entries. The extensive growth of repeat unit characterization was possible by applying the novel ReUPred annotation method over the entire Protein Data Bank, with data quality is guaranteed by an extensive manual validation for >60% of the entries. The updated web interface includes a new search engine for complex queries and a fully re-designed entry page for a better overview of structural data. It is now possible to compare unit positions, together with secondary structure, fold information and Pfam domains. Moreover, a new classification level has been introduced on top of the existing scheme as an independent layer for sequence similarity relationships at 40%, 60% and 90% identity. PMID:27899671

  19. Radiation induced currents in MRI RF coils: application to linac/MRI integration

    PubMed Central

    Burke, B; Fallone, B G; Rathee, S

    2010-01-01

    The integration of medical linear accelerators (linac) with magnetic resonance imaging (MRI) systems is advancing the current state of image-guided radiotherapy. The MRI in these integrated units will provide real-time, accurate tumor locations for radiotherapy treatment, thus decreasing geometric margins around tumors and reducing normal tissue damage. In the real-time operation of these integrated systems, the radiofrequency (RF) coils of MRI will be irradiated with radiation pulses from the linac. The effect of pulsed radiation on MRI radio frequency (RF) coils is not known and must be studied. The instantaneous radiation induced current (RIC) in two different MRI RF coils were measured and presented. The frequency spectra of the induced currents were calculated. Some basic characterization of the RIC was also done: isolation of the RF coil component responsible for RIC, dependence of RIC on dose rate, and effect of wax buildup placed on coil on RIC. Both the time and frequency characteristics of the RIC were seen to vary with the MRI RF coil used. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence on dose rate was seen. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. This study shows a measurable RIC present in MRI RF coils. This unwanted current could be possibly detrimental to the signal to noise ratio in MRI and produce image artifacts. PMID:20071754

  20. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    PubMed Central

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding. PMID:25965548

  1. Multichannel compressive sensing MRI using noiselet encoding.

    PubMed

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  2. Sodium MRI in human heart: a review.

    PubMed

    Bottomley, Paul A

    2016-02-01

    This paper offers a critical review of the properties, methods and potential clinical application of sodium ((23)Na) MRI in human heart. Because the tissue sodium concentration (TSC) in heart is about ~40 µmol/g wet weight, and the (23)Na gyromagnetic ratio and sensitivity are respectively about one-quarter and one-11th of that of hydrogen ((1)H), the signal-to-noise ratio of (23)Na MRI in the heart is about one-6000th of that of conventional cardiac (1)H MRI. In addition, as a quadrupolar nucleus, (23)Na exhibits ultra-short and multi-component relaxation behavior (T1 ~ 30 ms; T2 ~ 0.5-4 ms and 12-20 ms), which requires fast, specialized, ultra-short echo-time MRI sequences, especially for quantifying TSC. Cardiac (23)Na MRI studies from 1.5 to 7 T measure a volume-weighted sum of intra- and extra-cellular components present at cytosolic concentrations of 10-15 mM and 135-150 mM in healthy tissue, respectively, at a spatial resolution of about 0.1-1 ml in 10 min or so. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved without the use of potentially toxic shift reagents. Nevertheless, increases in TSC attributable to an influx of intra-cellular sodium and/or increased extra-cellular volume have been demonstrated in human myocardial infarction consistent with prior animal studies, and arguably might also be seen in future studies of ischemia and cardiomyopathies--especially those involving defects in sodium transport. While technical implementation remains a hurdle, a central question for clinical use is whether cardiac (23)Na MRI can deliver useful information unobtainable by other more convenient methods, including (1)H MRI.

  3. Integration of EEG/MEG with MRI and fMRI in Functional Neuroimaging

    PubMed Central

    Liu, Zhongming; Ding, Lei; He, Bin

    2007-01-01

    EEG and MEG are important functional neuroimaging modalities for studying the temporal dynamics of neural activities and interactions, but the accurate localization of neural activities still remains a challenging problem. Combining EEG/MEG with MRI or/and functional MRI (fMRI) holds promise to significantly increase the spatial resolution of electromagnetic source imaging, and at the same time, allows tracing the rapid neural processes and information pathways within the brain, which cannot be achieved using these modalities in isolation. In this paper, we review some recent progresses in multimodal neuroimaging, with special emphasis on the integration of EEG, MEG with MRI and fMRI. Some examples are shown to illustrate the importance of the combined source analysis in clinical and experimental studies. PMID:16898658

  4. Vectorette PCR isolation of microsatellite repeat sequences using anchored dinucleotide repeat primers.

    PubMed Central

    Lench, N J; Norris, A; Bailey, A; Booth, A; Markham, A F

    1996-01-01

    We have developed a vectorette PCR approach to provide an improved method for isolation of microsatellite repeats. The modified procedure relies on PCR amplification using a vectorette-specific primer in combination with one of a panel of anchored dinucleotide repeat primers. The target DNA to be screened for microsatellite sequences can be from YAC, P1, cosmid, bacteriophage or plasmid clones. We have used this technique to isolate novel, polymorphic microsatellite repeats from clones containing the amelogenin gene (AMGX) located on human chromosome Xp22.3. PMID:8668553

  5. Optimizing repeat liver transplant graft utility through strategic matching of donor and recipient characteristics.

    PubMed

    Hung, Kenneth; Gralla, Jane; Dodge, Jennifer L; Bambha, Kiran M; Dirchwolf, Melisa; Rosen, Hugo R; Biggins, Scott W

    2015-11-01

    Repeat liver transplantation (LT) is controversial because of inferior outcomes versus primary LT. A minimum 1-year expected post-re-LT survival of 50% has been proposed. We aimed to identify combinations of Model for End-Stage Liver Disease (MELD), donor risk index (DRI), and recipient characteristics achieving this graft survival threshold. We identified re-LT recipients listed in the United States from March 2002 to January 2010 with > 90 days between primary LT and listing for re-LT. Using Cox regression, we estimated the expected probability of 1-year graft survival and identified combinations of MELD, DRI, and recipient characteristics attaining >50% expected 1-year graft survival. Re-LT recipients (n = 1418) had a median MELD of 26 and median age of 52 years. Expected 1-year graft survival exceeded 50% regardless of MELD or DRI in Caucasian recipients who were not infected with hepatitis C virus (HCV) of all ages and Caucasian HCV-infected recipients <50 years old. As age increased in HCV-infected Caucasian and non-HCV-infected African American recipients, lower MELD scores or lower DRI grafts were needed to attain the graft survival threshold. As MELD scores increased in HCV-infected African American recipients, lower-DRI livers were required to achieve the graft survival threshold. Use of high-DRI livers (>1.44) in HCV-infected recipients with a MELD score > 26 at re-LT failed to achieve the graft survival threshold with recipient age ≥ 60 years (any race), as well as at age ≥ 50 years for Caucasians and at age < 50 years for African Americans. Strategic donor selection can achieve >50% expected 1-year graft survival even in high-risk re-LT recipients (HCV infected, older age, African American race, high MELD scores). Low-risk transplant recipients (age < 50 years, non-HCV-infected) can achieve the survival threshold with varying DRI and MELD scores.

  6. Biomedical Applications of Sodium MRI In Vivo

    PubMed Central

    Madelin, Guillaume; Regatte, Ravinder R.

    2013-01-01

    In this article, we present an up-to-date overview of the potential biomedical applications of sodium MRI in vivo. Sodium MRI is a subject of increasing interest in translational imaging research as it can give some direct and quantitative biochemical information on the tissue viability, cell integrity and function, and therefore not only help the diagnosis but also the prognosis of diseases and treatment outcomes. It has already been applied in vivo in most of human tissues, such as brain for stroke or tumor detection and therapeutic response, in breast cancer, in articular cartilage, in muscle and in kidney, and it was shown in some studies that it could provide very useful new information not available through standard proton MRI. However, this technique is still very challenging due to the low detectable sodium signal in biological tissue with MRI and hardware/software limitations of the clinical scanners. The article is divided in three parts: (1) the role of sodium in biological tissues, (2) a short review on sodium magnetic resonance, and (3) a review of some studies on sodium MRI on different organs/diseases to date. PMID:23722972

  7. Dental MRI using wireless intraoral coils

    PubMed Central

    Ludwig, Ute; Eisenbeiss, Anne-Katrin; Scheifele, Christian; Nelson, Katja; Bock, Michael; Hennig, Jürgen; von Elverfeldt, Dominik; Herdt, Olga; Flügge, Tabea; Hövener, Jan-Bernd

    2016-01-01

    Currently, the gold standard for dental imaging is projection radiography or cone-beam computed tomography (CBCT). These methods are fast and cost-efficient, but exhibit poor soft tissue contrast and expose the patient to ionizing radiation (X-rays). The need for an alternative imaging modality e.g. for soft tissue management has stimulated a rising interest in dental magnetic resonance imaging (MRI) which provides superior soft tissue contrast. Compared to X-ray imaging, however, so far the spatial resolution of MRI is lower and the scan time is longer. In this contribution, we describe wireless, inductively-coupled intraoral coils whose local sensitivity enables high resolution MRI of dental soft tissue. In comparison to CBCT, a similar image quality with complementary contrast was obtained ex vivo. In-vivo, a voxel size of the order of 250∙250∙500 μm3 was achieved in 4 min only. Compared to dental MRI acquired with clinical equipment, the quality of the images was superior in the sensitive volume of the coils and is expected to improve the planning of interventions and monitoring thereafter. This method may enable a more accurate dental diagnosis and avoid unnecessary interventions, improving patient welfare and bringing MRI a step closer to becoming a radiation-free alternative for dental imaging. PMID:27021387

  8. Dental MRI using wireless intraoral coils

    NASA Astrophysics Data System (ADS)

    Ludwig, Ute; Eisenbeiss, Anne-Katrin; Scheifele, Christian; Nelson, Katja; Bock, Michael; Hennig, Jürgen; von Elverfeldt, Dominik; Herdt, Olga; Flügge, Tabea; Hövener, Jan-Bernd

    2016-03-01

    Currently, the gold standard for dental imaging is projection radiography or cone-beam computed tomography (CBCT). These methods are fast and cost-efficient, but exhibit poor soft tissue contrast and expose the patient to ionizing radiation (X-rays). The need for an alternative imaging modality e.g. for soft tissue management has stimulated a rising interest in dental magnetic resonance imaging (MRI) which provides superior soft tissue contrast. Compared to X-ray imaging, however, so far the spatial resolution of MRI is lower and the scan time is longer. In this contribution, we describe wireless, inductively-coupled intraoral coils whose local sensitivity enables high resolution MRI of dental soft tissue. In comparison to CBCT, a similar image quality with complementary contrast was obtained ex vivo. In-vivo, a voxel size of the order of 250•250•500 μm3 was achieved in 4 min only. Compared to dental MRI acquired with clinical equipment, the quality of the images was superior in the sensitive volume of the coils and is expected to improve the planning of interventions and monitoring thereafter. This method may enable a more accurate dental diagnosis and avoid unnecessary interventions, improving patient welfare and bringing MRI a step closer to becoming a radiation-free alternative for dental imaging.

  9. Transition from Collisionless to Collisional MRI

    SciTech Connect

    Prateek Sharma; Gregory W. Hammett; Eliot Quataert

    2003-07-24

    Recent calculations by Quataert et al. (2002) found that the growth rates of the magnetorotational instability (MRI) in a collisionless plasma can differ significantly from those calculated using MHD. This can be important in hot accretion flows around compact objects. In this paper, we study the transition from the collisionless kinetic regime to the collisional MHD regime, mapping out the dependence of the MRI growth rate on collisionality. A kinetic closure scheme for a magnetized plasma is used that includes the effect of collisions via a BGK operator. The transition to MHD occurs as the mean free path becomes short compared to the parallel wavelength 2*/k(sub)||. In the weak magnetic field regime where the Alfven and MRI frequencies w are small compared to the sound wave frequency k(sub)||c(sub)0, the dynamics are still effectively collisionless even if omega << v, so long as the collision frequency v << k(sub)||c(sub)0; for an accretion flow this requires n less than or approximately equal to *(square root of b). The low collisionality regime not only modifies the MRI growth rate, but also introduces collisionless Landau or Barnes damping of long wavelength modes, which may be important for the nonlinear saturation of the MRI.

  10. Functional MRI applications in epilepsy surgery.

    PubMed

    Beers, Craig A; Federico, Paolo

    2012-05-01

    Functional magnetic resonance imaging (fMRI) is a non-invasive neuroimaging technique that has grown rapidly in popularity over the past decade. It is already prevalent in psychology, cognitive and basic neuroscience research and is being used increasingly as a tool for clinical decision-making in epilepsy. It has been used to determine language location and laterality in patients, sometimes eliminating the need for invasive tests. fMRI can been used pre-surgically to guide resection margins, preserving eloquent cortex. Other fMRI paradigms assessing memory, visual and somatosensory systems have limited clinical applications currently, but show great promise. Simultaneous recording of electroencephalogram (EEG) and fMRI has also provided insights into the networks underlying seizure generation and is increasingly being used in epilepsy centres. In this review, we present some of the current clinical applications for fMRI in the pre-surgical assessment of epilepsy patients, and examine a number of new techniques that may soon become clinically relevant.

  11. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H (Inventor); Hahn, Inseob (Inventor)

    2010-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  12. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2011-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  13. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2013-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  14. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2014-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  15. The Use of MRI Modeling to Enhance Osteochondral Transfer in Segmental Kienböck's Disease.

    PubMed

    Barber, Lauren; Koff, Matthew F; Virtue, Patrick; Lipman, Joseph P; Hotchkiss, Robert J; Potter, Hollis G

    2012-04-01

    Kienböck's disease, defined as avascular necrosis of the lunate, is a relatively rare condition with a poorly understood etiology. Conservative and invasive treatments for Kienböck's disease exist, including wrist immobilization, surgical joint-leveling procedures, vascularized bone grafting, proximal row carpectomy, and total wrist arthrodesis. Staging Kienböck's disease using radiography assumes near complete avascularity of the lunate. The staging distinguishes only the "state of collapse" in an ordinal classification scheme and does not allow localization or indicate partial involvement of the lunate, which the image contrast from MRI may provide. In this short communication, we report the treatment of a patient's Kienböck's disease by combining MRI with mathematical modeling to optimize the congruency between the curvature of donor and recipient sites of an autologous osteoarticular plug transfer. Follow-up MRI and radiographs at 1 year postoperatively demonstrated gradual graft incorporation and bone healing. The purpose of this study was to describe the feasibility of a novel surgical technique. The results indicate that donor site selection for autologous osteoarticular transfer using a quantitative evaluation of articular surface curvature may be beneficial for optimizing the likelihood for restoring the radius of curvature and thus joint articulation following cartilage repair.

  16. Stability of dental waxes following repeated heatings.

    PubMed

    Kotsiomiti, E; McCabe, J F

    1995-02-01

    The flow and strength properties of dental waxes were examined following excessive and repeated heatings of the materials. For one product, the flow at 40 +/- 0.5 degrees C was reduced by 25.3% following heating above 200 degrees C. A decrease of the elastic modulus at 20 +/- 1 degree C by approximately 66% was observed in some cases after the heating temperature had been increased to 300 degrees C. Property variations were related to compositional changes, which were investigated by infrared spectoscopy and thermal analysis. Exposure of dental waxes to temperatures higher than 200 degrees C, particularly if it is repeated, may affect the composition and properties, resulting in inferior materials.

  17. Overcoming fixation with repeated memory suppression.

    PubMed

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  18. Mutagenic inverted repeat assisted genome engineering (MIRAGE).

    PubMed

    Nair, Nikhil U; Zhao, Huimin

    2009-01-01

    Here we describe a one-step method to create precise modifications in the genome of Saccharomyces cerevisiae as a tool for synthetic biology, metabolic engineering, systems biology and genetic studies. Through homologous recombination, a mutagenesis cassette containing an inverted repeat of selection marker(s) is integrated into the genome. Due to its inherent instability in genomic DNA, the inverted repeat catalyzes spontaneous self-excision, resulting in precise genome modification. Since this excision occurs at very high frequencies, selection for the integration event can be followed immediately by counterselection, without the need for growth in permissive conditions. This is the first time a truly one-step method has been described for genome modification in any organism.

  19. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  20. Repeat-PPM Super-Symbol Synchronization

    NASA Astrophysics Data System (ADS)

    Connelly, J.

    2016-11-01

    To attain a wider range of data rates in pulse position modulation (PPM) schemes with constrained pulse durations, the sender can repeat a PPM symbol multiple times, forming a super-symbol. In addition to the slot and symbol synchronization typically required for PPM, the receiver must also properly align the noisy super-symbols. We present a low-complexity approximation of the maximum-likelihood method for performing super-symbol synchronization without use of synchronization sequences. We provide simulation results demonstrating performance advantage when PPM symbols are spread by a pseudo-noise sequence, as opposed to simply repeating. Additionally, the results suggest that this super-symbol synchronization technique requires signal levels below those required for reliable communication. This validates that the PPM spreading approach proposed to CCSDS can work properly as part of the overall scheme.

  1. Repeated interactions in open quantum systems

    SciTech Connect

    Bruneau, Laurent; Joye, Alain; Merkli, Marco

    2014-07-15

    Analyzing the dynamics of open quantum systems has a long history in mathematics and physics. Depending on the system at hand, basic physical phenomena that one would like to explain are, for example, convergence to equilibrium, the dynamics of quantum coherences (decoherence) and quantum correlations (entanglement), or the emergence of heat and particle fluxes in non-equilibrium situations. From the mathematical physics perspective, one of the main challenges is to derive the irreversible dynamics of the open system, starting from a unitary dynamics of the system and its environment. The repeated interactions systems considered in these notes are models of non-equilibrium quantum statistical mechanics. They are relevant in quantum optics, and more generally, serve as a relatively well treatable approximation of a more difficult quantum dynamics. In particular, the repeated interaction models allow to determine the large time (stationary) asymptotics of quantum systems out of equilibrium.

  2. Risk of Recurrent Helicobacter pylori Infection 1 Year After Initial Eradication Therapy in 7 Latin American Communities

    PubMed Central

    Morgan, Douglas R.; Torres, Javier; Sexton, Rachael; Herrero, Rolando; Salazar-Martínez, Eduardo; Robert Greenberg, E.; Bravo, Luis Eduardo; Dominguez, Ricardo L.; Ferreccio, Catterina; Lazcano-Ponce, Eduardo C.; Meza-Montenegro, Maria Mercedes; Peña, Edgar M.; Peña, Rodolfo; Correa, Pelayo; Martínez, María Elena; Chey, William D.; Valdivieso, Manuel; Anderson, Garnet L.; Goodman, Gary E.; Crowley, John J.; Baker, Laurence H.

    2013-01-01

    Importance The long-term effectiveness of Helicobacter pylori eradication programs for preventing gastric cancer will depend on recurrence risk and individual and community factors. Objective To estimate risk of H pylori recurrence and assess factors associated with successful eradication 1 year after treatment. Design, Setting, and Participants Cohort analysis of 1463 randomized trial participants aged 21 to 65 years from 7 Latin American communities, who were treated for H pylori and observed between September 2009 and July 2011. Interventions Randomization to 1 of 3 treatment groups: 14-day lansoprazole, amoxicillin, and clarithromycin (triple therapy); 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential); or 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant). Participants with a positive (13) C-urea breath test (UBT) 6 to 8 weeks posttreatment were offered voluntary re-treatment with 14-day bismuth-based quadruple therapy. Measurements Recurrent infection after a negative posttreatment UBT and factors associated with successful eradication at 1-year follow-up. Results Among participants with UBT-negative results who had a 1-year follow-up UBT (n=1091), 125 tested UBT positive, a recurrence risk of 11.5% (95% CI, 9.6%–13.5%). Recurrence was significantly associated with study site (P=.03), nonadherence to initial therapy (adjusted odds ratio [AOR], 2.94; 95% CI, 1.31–6.13; P=.01), and children in the household (AOR, 1.17; 95% CI, 1.01–1.35 per child; P=.03). Of the 281 with positive posttreatment UBT results, 138 completed re-treatment, of whom 93 tested UBT negative at 1 year. Among the 1340 who had a 1-year UBT, 80.4% (95% CI, 76.4%–83.9%), 79.8% (95% CI, 75.8%–83.5%), and 77.8% (95% CI, 73.6%–81.6%) had UBT-negative results in the triple, sequential, and concomitant groups, respectively (P=.61), with 79.3% overall effectiveness (95% CI, 77.1%–81.5%). In a

  3. Effect of the INSIGHT Responsive Parenting Intervention on Rapid Infant Weight Gain and Overweight Status at Age 1 Year

    PubMed Central

    Savage, Jennifer S.; Birch, Leann L.; Marini, Michele; Anzman-Frasca, Stephanie; Paul, Ian M.

    2016-01-01

    IMPORTANCE Rapid infant weight gain is associated with later obesity, but interventions to prevent rapid infant growth and reduce risk for overweight status in infancy are lacking. OBJECTIVE To examine the effect of a responsive parenting (RP) intervention on infant weight gain between birth and 28 weeks and overweight status at age 1 year. DESIGN, SETTING, AND PARTICIPANTS The Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) study is an ongoing randomized clinical trial comparing an RP intervention designed to prevent childhood obesity with a safety control. The study includes primiparous mother-newborn dyads (n = 291) and was conducted at the Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, in addition to home visits. Enrollment was initiated in January 2012, and evaluable population analyses for this study were conducted between April 2015 and November 2015. INTERVENTIONS At 2 weeks post partum, initial intervention materials appropriate to the assigned treatment group were mailed to the participant’s home. Research nurses conducted home visits at 3 weeks, 16 weeks, 28 weeks, and 40 weeks, and a research center visit occurred at 1 year. The Intervention Nurses Start Infants Growing on Healthy Trajectories curriculum included messages about infant feeding, sleep hygiene, active social play, emotion regulation, and growth record education. The control group received a developmentally appropriate home safety intervention also delivered by nurse home visitors. MAIN OUTCOMES AND MEASURES Conditional weight gain from birth to 28 weeks was calculated. General linear models examined intervention effect on conditional weight gain. The intervention’s effect on infant weight-for-length percentiles was tested using analysis of variance. Logistic regression compared the odds of overweight status (weight for length ≥95th percentile) at 1 year as a function of conditional weight gain. RESULTS Of the mothers included in the

  4. Nucleosome repeat lengths and columnar chromatin structure.

    PubMed

    Trifonov, Edward N

    2016-06-01

    Thorough quantitative study of nucleosome repeat length (NRL) distributions, conducted in 1992 by J. Widom, resulted in a striking observation that the linker lengths between the nucleosomes are quantized. Comparison of the NRL average values with the MNase cut distances predicted from the hypothetical columnar structure of chromatin (this work) shows a close correspondence between the two. This strongly suggests that the NRL distribution, actually, reflects the dominant role of columnar chromatin structure common for all eukaryotes.

  5. Identical repeated backbone of the human genome

    PubMed Central

    2010-01-01

    Background Identical sequences with a minimal length of about 300 base pairs (bp) have been involved in the generation of various meiotic/mitotic genomic rearrangements through non-allelic homologous recombination (NAHR) events. Genomic disorders and structural variation, together with gene remodelling processes have been associated with many of these rearrangements. Based on these observations, we identified and integrated all the 100% identical repeats of at least 300 bp in the NCBI version 36.2 human genome reference assembly into non-overlapping regions, thus defining the Identical Repeated Backbone (IRB) of the reference human genome. Results The IRB sequences are distributed all over the genome in 66,600 regions, which correspond to ~2% of the total NCBI human genome reference assembly. Important structural and functional elements such as common repeats, segmental duplications, and genes are contained in the IRB. About 80% of the IRB bp overlap with known copy-number variants (CNVs). By analyzing the genes embedded in the IRB, we were able to detect some identical genes not previously included in the Ensembl release 50 annotation of human genes. In addition, we found evidence of IRB gene copy-number polymorphisms in raw sequence reads of two diploid sequenced genomes. Conclusions In general, the IRB offers new insight into the complex organization of the identical repeated sequences of the human genome. It provides an accurate map of potential NAHR sites which could be used in targeting the study of novel CNVs, predicting DNA copy-number variation in newly sequenced genomes, and improve genome annotation. PMID:20096123

  6. Repeatability of Response to Asthma Medications

    PubMed Central

    Wu, Ann; Tantisira, Kelan; Li, Lingling; Schuemann, Brooke; Weiss, Scott

    2010-01-01

    Background Pharmacogenetic studies of drug response in asthma assume that patients respond consistently to a treatment but that treatment response varies across patients, however, no formal studies have demonstrated this. Objective To determine the repeatability of commonly used outcomes for treatment response to asthma medications: bronchodilator response, forced expiratory volume in 1 second (FEV1), and provocative concentration of methacholine producing a 20% decline in FEV1 (PC20). Methods The Childhood Asthma Management Program (CAMP) was a multi-center clinical trial of children randomized to receiving budesonide, nedocromil, or placebo. We determined the intraclass correlation coefficient (ICC) for each outcome over repeated visits over four years in CAMP using mixed effects regression models. We adjusted for the covariates: age, race/ethnicity, height, family income, parental education, and symptom score. We incorporated each outcome for each child as repeated outcome measurements and stratified by treatment group. Results The ICC for bronchodilator response was 0.31 in the budesonide group, 0.35 in the nedocromil group, and 0.40 in the placebo group, after adjusting for covariates. The ICC for FEV1 was 0.71 in the budesonide group, 0.60 in the nedocromil group, and 0.69 in the placebo group, after adjusting for covariates. The ICC for PC20 was 0.67 in the budesonide and placebo groups and 0.73 in the nedocromil group, after adjusting for covariates. Conclusion The within treatment group repeatability of FEV1 and PC20 are high; thus these phenotypes are heritable. FEV1 and PC20 may be better phenotypes than bronchodilator response for studies of treatment response in asthma. PMID:19064281

  7. 2D Metals by Repeated Size Reduction.

    PubMed

    Liu, Hanwen; Tang, Hao; Fang, Minghao; Si, Wenjie; Zhang, Qinghua; Huang, Zhaohui; Gu, Lin; Pan, Wei; Yao, Jie; Nan, Cewen; Wu, Hui

    2016-10-01

    A general and convenient strategy for manufacturing freestanding metal nanolayers is developed on large scale. By the simple process of repeatedly folding and calendering stacked metal sheets followed by chemical etching, free-standing 2D metal (e.g., Ag, Au, Fe, Cu, and Ni) nanosheets are obtained with thicknesses as small as 1 nm and with sizes of the order of several micrometers.

  8. Automatic-repeat-request error control schemes

    NASA Technical Reports Server (NTRS)

    Lin, S.; Costello, D. J., Jr.; Miller, M. J.

    1983-01-01

    Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed.

  9. Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI

    SciTech Connect

    Frohwein, Lynn J. Schäfers, Klaus P.; Hoerr, Verena; Faber, Cornelius

    2015-07-15

    Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging (MRI) data can be a challenging task in whole-body PET-MRI. The quality of the registration between these two modalities in large field-of-views (FOV) is often degraded by geometric distortions of the MRI data. The distortions at the edges of large FOVs mainly originate from MRI gradient nonlinearities. This work describes a method to measure and correct for these kind of geometric distortions in small animal MRI scanners to improve the registration accuracy of PET and MRI data. Methods: The authors have developed a geometric phantom which allows the measurement of geometric distortions in all spatial axes via control points. These control points are detected semiautomatically in both PET and MRI data with a subpixel accuracy. The spatial transformation between PET and MRI data is determined with these control points via 3D thin-plate splines (3D TPS). The transformation derived from the 3D TPS is finally applied to real MRI mouse data, which were acquired with the same scan parameters used in the phantom data acquisitions. Additionally, the influence of the phantom material on the homogeneity of the magnetic field is determined via field mapping. Results: The spatial shift according to the magnetic field homogeneity caused by the phantom material was determined to a mean of 0.1 mm. The results of the correction show that distortion with a maximum error of 4 mm could be reduced to less than 1 mm with the proposed correction method. Furthermore, the control point-based registration of PET and MRI data showed improved congruence after correction. Conclusions: The developed phantom has been shown to have no considerable negative effect on the homogeneity of the magnetic field. The proposed method yields an appropriate correction of the measured MRI distortion and is able to improve the PET and MRI registration. Furthermore, the method is applicable to whole-body small animal

  10. Predictors of Shoulder Pain and Disability Index (SPADI) and work status after 1 year in patients with subacromial shoulder pain

    PubMed Central

    2010-01-01

    Background Shoulder pain is a common complaint in primary health care and has an unfavourable outcome in many patients. The objectives were to identify predictors for pain and disability (SPADI) and work status in patients with subacromial shoulder pain. Methods Secondary analyses of data from a randomized clinical controlled trial were performed. Outcome measures were the absolute values of the combined Shoulder Pain and Disability Index (SPADI) and work status 1 year after treatment with supervised exercises (SE) or radial extracorporeal shockwave therapy (rESWT). Predictors of outcome were investigated using multiple linear regression (SPADI) and logistic regression (work status). Results 104 patients were included. Low education (≤ 12 years), previous shoulder pain, and a high baseline SPADI score predicted poor results with these variables explaining 29.9% of the variance in SPADI score at 1 year. Low education and poor self-reported health status predicted a work status of "not working": Odds Ratio, OR = 4.3(95% CI (1.3 to 14.9)), p = 0.02 for education, and OR = 1.06 (95% CI (1.0 to 1.1)), p = 0.001 for self-reported health status, respectively. Adjustments for age, gender, and treatment group were performed, but did not change the results. Conclusion Education was the most consistent predictor of pain and disability, and work status at 1 year follow-up. Also, baseline SPADI score, previous shoulder pain and self-reported health status predicted outcome. Trial registration Clinical trials NCT00653081 PMID:20863369

  11. Individual, physical and psychological risk factors for neck pain in Australian office workers: a 1-year longitudinal study.

    PubMed

    Hush, Julia M; Michaleff, Zoe; Maher, Christopher G; Refshauge, Kathryn

    2009-10-01

    Neck pain is more prevalent in office workers than in the general community. To date, findings from prospective studies that investigated causal relationships between putative risk factors and the onset of neck pain in this population have been limited by high loss to follow-up. The aim of this research was to prospectively evaluate a range of risk factors for neck pain in office workers, using validated and reliable objective measures as well as attain an estimate of 1-year incidence. We assembled a cohort of 53 office workers without neck pain and measured individual, physical, workplace and psychological factors at baseline. We followed participants for 1 year to measure the incidence of neck pain. We achieved 100% participant follow-up. Cox regression analysis was applied to examine the relationship between the putative risk factors and the cumulative incidence of neck pain. The 1-year incidence proportion of neck pain in Australian office workers was estimated in this study to be 0.49 (95% CI 0.36-0.62). Predictors of neck pain with moderate to large effect sizes were female gender (HR: 3.07; 95% CI: 1.18-7.99) and high psychological stress (HR: 1.64; 95% CI: 0.66-4.07). Protective factors included increased mobility of the cervical spine (HR: 0.44; 95% CI: 0.19-1.05) and frequent exercise (HR: 0.64; 95% CI: 0.27-1.51). These results reveal that neck pain is common in Australian office workers and that there are risk factors that are potentially modifiable.

  12. Impact of Different Childhood Adversities on 1-Year Outcomes of Psychotic Disorder in the Genetics and Psychosis Study.

    PubMed

    Trotta, Antonella; Murray, Robin M; David, Anthony S; Kolliakou, Anna; O'Connor, Jennifer; Di Forti, Marta; Dazzan, Paola; Mondelli, Valeria; Morgan, Craig; Fisher, Helen L

    2016-03-01

    While the role of childhood adversity in increasing the risk of psychosis has been extensively investigated, it is not clear what the impact of early adverse experiences is on the outcomes of psychotic disorders. Therefore, we investigated associations between childhood adversity and 1-year outcomes in 285 first-presentation psychosis patients. Exposure to childhood adversity prior to 17 years of age was assessed using the Childhood Experience of Care and Abuse Questionnaire. Data on illness course, symptom remission, length of psychiatric hospitalization, compliance with medication, employment, and relationship status were extracted from clinical records for the year following first contact with mental health services for psychosis. Seventy-one percent of patients reported exposure to at least 1 type of childhood adversity (physical abuse, sexual abuse, parental separation, parental death, disrupted family arrangements, or being taken into care). No robust associations were found between childhood adversity and illness course or remission. However, childhood physical abuse was associated with almost 3-fold increased odds of not being in a relationship at 1-year follow-up compared to patients who did not report such adverse experiences. There was also evidence of a significant association between parental separation in childhood and longer admissions to psychiatric wards during 1-year follow-up and 2-fold increased odds of noncompliance with medication compared to those not separated from their parents. Therefore, our findings suggest that there may be some specificity in the impact of childhood adversity on service use and social functioning among psychosis patients over the first year following presentation to mental health services.

  13. Genomic Repeat Abundances Contain Phylogenetic Signal

    PubMed Central

    Dodsworth, Steven; Chase, Mark W.; Kelly, Laura J.; Leitch, Ilia J.; Macas, Jiří; Novák, Petr; Piednoël, Mathieu; Weiss-Schneeweiss, Hanna; Leitch, Andrew R.

    2015-01-01

    A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution. PMID:25261464

  14. Landauer's Principle in Repeated Interaction Systems

    NASA Astrophysics Data System (ADS)

    Hanson, Eric P.; Joye, Alain; Pautrat, Yan; Raquépas, Renaud

    2017-01-01

    We study Landauer's Principle for Repeated Interaction Systems (RIS) consisting of a reference quantum system S in contact with a structured environment E made of a chain of independent quantum probes; S interacts with each probe, for a fixed duration, in sequence. We first adapt Landauer's lower bound, which relates the energy variation of the environment E to a decrease of entropy of the system S during the evolution, to the peculiar discrete time dynamics of RIS. Then we consider RIS with a structured environment E displaying small variations of order {T^{-1}} between the successive probes encountered by S, after {n ˜eq T} interactions, in keeping with adiabatic scaling. We establish a discrete time non-unitary adiabatic theorem to approximate the reduced dynamics of S in this regime, in order to tackle the adiabatic limit of Landauer's bound. We find that saturation of Landauer's bound is related to a detailed balance condition on the repeated interaction system, reflecting the non-equilibrium nature of the repeated interaction system dynamics. This is to be contrasted with the generic saturation of Landauer's bound known to hold for continuous time evolution of an open quantum system interacting with a single thermal reservoir in the adiabatic regime.

  15. Agreement and repeatability of an infrared thermometer.

    PubMed

    Kelechi, Teresa J; Good, Angela; Mueller, Martina

    2011-01-01

    Recently, manufacturers have devised thermometers for home use by patients, such as the TempTouch Infrared Thermometer (TTIR; Diabetica Solutions, San Antonio, TX), which is designed with a long handle that can be used for self-monitoring localized skin temperature of the feet and legs. This study assessed the level of agreement and repeatability of the TTIR compared to a thermistor-type thermometer (TT; PeriFlux, 5020 Temperature Unit, Perimed, Stockholm, Sweden), the reference standard. In 17 healthy subjects, localized skin temperature was measured 8 cm above the right medial malleolus at baseline (Time 1), after a 10-minute rest period (Time 2), and after 10 minutes of cold provocation (Time 3) with a cryotherapy gel wrap placed around the lower legs using the TTIR and TT for temperature measurement. Scatter plots and correlation coefficients showed strong positive relationships between the two measurement methods at all three time points (Time 1: r = 0.95; Time 2: r = 0.97; and, Time 3: r = 0.87). Results showed a reasonable level of agreement between the two methods at Times 1 and 2 but not after cold provocation. Agreement between the methods appears to be better than repeatability within each method. Results for repeatability from both the TT and TTIR were very similar suggesting that there was a systematic bias with increasing temperatures between Time 1 and Time 2.

  16. Repeated-sprint ability: where are we?

    PubMed

    Dawson, Brian

    2012-09-01

    Repeated-sprint ability (RSA) is now well accepted as an important fitness component in team-sport performance. It is broadly described as the ability to perform repeated short (~3-4 s, 20-30 m) sprints with only brief (~10-30 s) recovery between bouts. Over the past 25 y a plethora of RSA tests have been trialed and reported in the literature. These range from a single set of ~6-10 short sprints, departing every 20-30 s, to team-sport game simulations involving repeating cycles of walk-jog-stride-sprint movements over 45-90 min. Such a wide range of RSA tests has not assisted the synthesis of research findings in this area, and questions remain regarding the optimal methods of training to best improve RSA. In addition, how RSA test scores relate to player "work rate," match performance, or both requires further investigation to improve the application of RSA testing and training to elite team-sport athletes.

  17. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  18. Orthologous repeats and mammalian phylogenetic inference

    PubMed Central

    Bashir, Ali; Ye, Chun; Price, Alkes L.; Bafna, Vineet

    2005-01-01

    Determining phylogenetic relationships between species is a difficult problem, and many phylogenetic relationships remain unresolved, even among eutherian mammals. Repetitive elements provide excellent markers for phylogenetic analysis, because their mode of evolution is predominantly homoplasy-free and unidirectional. Historically, phylogenetic studies using repetitive elements have relied on biological methods such as PCR analysis, and computational inference is limited to a few isolated repeats. Here, we present a novel computational method for inferring phylogenetic relationships from partial sequence data using orthologous repeats. We apply our method to reconstructing the phylogeny of 28 mammals, using more than 1000 orthologous repeats obtained from sequence data available from the NISC Comparative Sequencing Program. The resulting phylogeny has robust bootstrap numbers, and broadly matches results from previous studies which were obtained using entirely different data and methods. In addition, we shed light on some of the debatable aspects of the phylogeny. With rapid expansion of available partial sequence data, computational analysis of repetitive elements holds great promise for the future of phylogenetic inference. PMID:15998912

  19. Repeat Stereotactic Radiosurgery for Acoustic Neuromas

    SciTech Connect

    Kano, Hideyuki; Kondziolka, Douglas; Niranjan, Ajay M.Ch.; Flannery, Thomas J.; Flickinger, John C.; Lunsford, L. Dade

    2010-02-01

    Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months). Results: At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS. Conclusions: With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.

  20. Probable transmission of Yersinia enterocolitica from a pet dog with diarrhoea to a 1-year-old infant

    PubMed Central

    Hetem, D J; Pekelharing, M; Thijsen, S F T

    2013-01-01

    We report a highly probable case of transmission of a Yersinia enterocolitica from a pet puppy dog, adopted from a Spanish asylum, to a 1-year-old girl. After several weeks of diarrhoea, a PCR detecting enteropathogenic bacteria was performed on the faeces, revealing Y enterocolitica. Following cultures yielded a Y enterocolitica biotype 4, serotype O:3 in the faeces of the girl as well as puppy dog. Despite antibiotic treatment, symptoms and shedding of the organism in the faeces endured during a 2 month period. PMID:23955982

  1. Effect of a fish oil diet on asthma: results of a 1-year double-blind study.

    PubMed

    Dry, J; Vincent, D

    1991-01-01

    Airway inflammation is a major component of asthma. Food intake of N-3 fatty acids (FA) is associated with a low incidence of inflammatory diseases, such as asthma. We treated 12 asthmatic patients with FA and report the positive results of this 1-year double-blind study. A positive effect on forced expiratory volume in 1 s was observed after the 9 month of treatment. Our results are in favor of the use of FA, but have to be confirmed by other studies.

  2. A Unified Model for Repeating and Non-repeating Fast Radio Bursts

    NASA Astrophysics Data System (ADS)

    Bagchi, Manjari

    2017-04-01

    The model that fast radio bursts (FRBs) are caused by plunges of asteroids onto neutron stars can explain both repeating and non-repeating bursts. If a neutron star passes through an asteroid belt around another star, there would be a series of bursts caused by a series of asteroid impacts. Moreover, the neutron star would cross the same belt repetitively if it were in a binary with the star hosting the asteroid belt, leading to a repeated series of bursts. I explore the properties of neutron star binaries that could lead to the only known repeating FRB so far (FRB121102). In this model, the next two epochs of bursts are expected around 2017 February 27 and 2017 December 18. On the other hand, if the asteroid belt is located around the neutron star itself, then a chance fall of an asteroid from that belt onto the neutron star would lead to a non-repeating burst. Even a neutron star grazing an asteroid belt can lead to a non-repeating burst caused by just one asteroid plunge during the grazing. This is possible even when the neutron star is in a binary with the asteroid-hosting star, if the belt and the neutron star orbit are non-coplanar.

  3. WE-B-BRD-00: MRI for Radiation Oncology

    SciTech Connect

    2015-06-15

    The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: Understand the difference between a standard and a radiotherapy-specific MRI QA program. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

  4. Monkey cortex through fMRI glasses.

    PubMed

    Vanduffel, Wim; Zhu, Qi; Orban, Guy A

    2014-08-06

    In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging.

  5. Motion correction in MRI of the brain

    PubMed Central

    Godenschweger, F; Kägebein, U; Stucht, D; Yarach, U; Sciarra, A; Yakupov, R; Lüsebrink, F; Schulze, P; Speck, O

    2016-01-01

    Subject motion in MRI is a relevant problem in the daily clinical routine as well as in scientific studies. Since the beginning of clinical use of MRI, many research groups have developed methods to suppress or correct motion artefacts. This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research. It explains the sources and types of motion and related artefacts, classifies and describes existing techniques for motion detection, compensation and correction and lists established and experimental approaches. Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition. Differences, benefits and drawbacks of different motion correction methods are discussed. PMID:26864183

  6. Plasma MRI Experiments at UW-Madison

    NASA Astrophysics Data System (ADS)

    Flanagan, K.; Clark, M.; Desangles, V.; Siller, R.; Wallace, J.; Weisberg, D.; Forest, C. B.

    2015-11-01

    Experiments for driving Keplerian-like flow profiles on both the Plasma Couette Experiment Upgrade (PCX-U) and the Wisconsin Plasma Astrophysics Laboratory (WiPAL) user facility are described. Instead of driving flow at the boundaries, as is typical in many liquid metal Couette experiments, a global drive is implemented. A large radial current is drawn across a small axial field generating torque across the whole profile. This global electrically driven flow is capable of producing profiles similar to Keplerian flow. PCX-U has been purposely constructed for MRI experiments, while similar experiments on the WiPAL device show the versatility of the user facility and provide a larger plasma volume. Numerical calculations show the predicted parameter spaces for exciting the MRI in these plasmas and the equilibrium flow profiles expected. In both devices, relevant MRI parameters appear to be within reach of typical operating characteristics.

  7. Alternative diagnoses at paediatric appendicitis MRI.

    PubMed

    Moore, M M; Kulaylat, A N; Brian, J M; Khaku, A; Hulse, M A; Engbrecht, B W; Methratta, S T; Boal, D K B

    2015-08-01

    As the utilization of MRI in the assessment for paediatric appendicitis increases in clinical practice, it is important to recognize alternative diagnoses as the cause of abdominal pain. The purpose of this review is to share our institution's experience using MRI in the evaluation of 510 paediatric patients presenting with suspected appendicitis over a 30 month interval (July 2011 to December 2013). An alternative diagnosis was documented in 98/510 (19.2%) patients; adnexal pathology (6.3%, n = 32), enteritis-colitis (6.3%, n = 32), and mesenteric adenitis (2.2%, n = 11) comprised the majority of cases. These common entities and other less frequent illustrative cases obtained during our overall institutional experience with MRI for suspected appendicitis are reviewed.

  8. Motion correction in MRI of the brain

    NASA Astrophysics Data System (ADS)

    Godenschweger, F.; Kägebein, U.; Stucht, D.; Yarach, U.; Sciarra, A.; Yakupov, R.; Lüsebrink, F.; Schulze, P.; Speck, O.

    2016-03-01

    Subject motion in MRI is a relevant problem in the daily clinical routine as well as in scientific studies. Since the beginning of clinical use of MRI, many research groups have developed methods to suppress or correct motion artefacts. This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research. It explains the sources and types of motion and related artefacts, classifies and describes existing techniques for motion detection, compensation and correction and lists established and experimental approaches. Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition. Differences, benefits and drawbacks of different motion correction methods are discussed.

  9. Segmentation of human brain using structural MRI.

    PubMed

    Helms, Gunther

    2016-04-01

    Segmentation of human brain using structural MRI is a key step of processing in imaging neuroscience. The methods have undergone a rapid development in the past two decades and are now widely available. This non-technical review aims at providing an overview and basic understanding of the most common software. Starting with the basis of structural MRI contrast in brain and imaging protocols, the concepts of voxel-based and surface-based segmentation are discussed. Special emphasis is given to the typical contrast features and morphological constraints of cortical and sub-cortical grey matter. In addition to the use for voxel-based morphometry, basic applications in quantitative MRI, cortical thickness estimations, and atrophy measurements as well as assignment of cortical regions and deep brain nuclei are briefly discussed. Finally, some fields for clinical applications are given.

  10. Phantom-based investigation of nonrigid registration constraints in mapping fMRI to anatomical MRI

    NASA Astrophysics Data System (ADS)

    Studholme, Colin; Constable, R. Todd; Duncan, James S.

    2000-06-01

    In previous work we have introduced an approach to improving the registration of EPI fMRI data with anatomical MRI by accounting for differences in magnetic field induced geometric distortion in the two types of MRI acquisition. In particular we began to explore the use of imaging physics based constraints in a non-rigid multi-modality registration algorithm. In this paper we present phantom based experimental work examining the behavior of different non-rigid registration constraints compared to a field map acquisition of the MRI distortion. This acquisition provides a pixel by pixel 'ground truth' estimate of the displacement field within the EPI data. In our registration based approach we employ a B-spline based estimate of the relative geometric distortion with a multi-grid optimization scheme. We maximize the normalized mutual information between the two types of MRI scans to estimate the B-Spline parameters. Using the field map estimates as a gold standard, registration estimates using no additional geometric constraints are compared to those using the spin echo based signal conservation. We also examine the use of logarithmic EPI values in the criteria to provide additional sensitivity in areas of low signal. Results indicate that registration of EPI to conventional MRI incorporating a spin echo distortion model can provide comparable estimates of geometric distortion to those from field mapping data without the need for significant additional acquisitions during each fMRI sequence.

  11. High Prevalence of Superior Labral Tears Diagnosed by MRI in Middle-Aged Patients With Asymptomatic Shoulders

    PubMed Central

    Schwartzberg, Randy; Reuss, Bryan L.; Burkhart, Bradd G.; Butterfield, Matt; Wu, James Y.; McLean, Kevin W.

    2016-01-01

    Background: The incidence of superior labral surgery has increased in the past decade in the United States, and a contributing factor could be an increased rate of superior labral tears diagnosed with magnetic resonance imaging (MRI). Prior MRI studies of the asymptomatic shoulder have focused on rotator cuff pathology or pathology in a narrow and specific group of athletes. Labral abnormalities have not previously been thoroughly evaluated in asymptomatic middle-aged individuals. Purpose: To evaluate the prevalence of superior labral tears diagnosed by MRI in the asymptomatic shoulders of middle-aged people (age range, 45-60 years). Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 53 asymptomatic adults (age range, 45-60 years) with no history of surgery or injury to either shoulder were included in the study. Physical examinations of all shoulders were performed. Noncontrast MRI (1.5 T) was performed in 1 randomly determined shoulder of each subject. Two fellowship-trained musculoskeletal radiologists who were blinded to the purpose of the study and ages of the subjects evaluated each MRI. Results: Radiologists interpreted the MRIs as consistent with superior labral tears in 55% and 72% of the cohort. Comparison of the radiological evaluations of the superior labra were moderate (κ = 0.410, P = .033). There were no differences in readings for superior labral tear regarding age (P = .87), sex (P = .41), whether the dominant shoulder underwent MRI (P = .99), whether the subject worked a physical job (P = .08), or whether the subject participated in overhead sports for a period of 1 year (P = .62). Conclusion: Superior labral tears are diagnosed with high frequency using MRI in 45- to 60-year-old individuals with asymptomatic shoulders. These shoulder MRI findings in middle-aged populations emphasize the need for supporting clinical judgment when making treatment decisions for this patient population. Clinical Relevance: To avoid

  12. Consecutive Case Series of Healed Single-Molar Sites Immediately Restored with Wide-Diameter Implants: A 1-Year Evaluation

    PubMed Central

    Cherfane, Pierre; Sojod, Bouchra

    2016-01-01

    Introduction. To evaluate outcomes of wide-diameter (6 mm) implants immediately provisionalized with cement-retained single crowns in posterior molar sites. Materials and Methods. Forty-eight consecutive patients received a total of 53 moderately rough-surface, 6 mm diameter implants in healed sites. All implants were immediately provisionalized with a cement-retained provisional crown. Final prosthesis with cement-retained porcelain fused to metal crowns was delivered 3–6 months later. Patients were followed up for 1 year. Outcome measures were implant failures and success rate, complications, marginal bone levels, bone level changes, papilla index, bleeding on probing, and inflammation. Results. One patient was lost to follow-up. At one year, the implant survival and success rate were 98.1%. The mean marginal bone loss after 1 year was −0.17 ± 1.84 mm. Ideal papilla score was recorded at 83.8% of the sites. More than 95.6% of the sites showed no bleeding or inflammation. No procedure-related or device-related adverse events were reported. Conclusion. Wide-diameter (6 mm) implants can safely and successfully replace single posterior molars. Longer follow-up studies are necessary to evaluate the long-term success of these implants. PMID:27195008

  13. Residential treatment for homeless female veterans with psychiatric and substance use disorders: effect on 1-year clinical outcomes.

    PubMed

    Harpaz-Rotem, Ilan; Rosenheck, Robert A; Desai, Rani

    2011-01-01

    Limited evidence shows that time-limited residential treatment (RT) is beneficial for homeless people with serious mental illness. The Department of Veterans Affairs has established 11 specialty programs for homeless female veterans. We present data comparing 1-year clinical outcomes in a group of veterans who did and did not receive at least 30 days of RT. Clients of the Homeless Women Veterans Programs were invited to participate in a follow-up study. They were interviewed every 3 months for 1 year. Those who received at least 30 days of RT in the 3 months after program entry (RT group) were compared with other program participants (no or <30 days RT [NRT] group) on measures of community functioning, psychiatric symptoms, and drug and alcohol use during the follow-up. The RT group had better outcomes on employment, social support, housing status, and psychiatric symptoms. They also had significantly increased use of drugs and alcohol compared with the NRT group. Data suggest that RT may have a beneficial effect on mental health outcomes in homeless women. This study, in conjunction with others, suggests that provision of stable housing may be an important element of recovery for homeless women with psychiatric problems, excluding substance use.

  14. Working Memory Deficit as a Risk Factor for Severe Apathy in Schizophrenia: A 1-Year Longitudinal Study.

    PubMed

    Raffard, Stéphane; Gutierrez, Laure-Anne; Yazbek, Hanan; Larue, Aurore; Boulenger, Jean-Philippe; Lançon, Christophe; Benoit, Michel; Faget, Catherine; Norton, Joanna; Capdevielle, Delphine

    2016-05-01

    Apathy, described as impaired motivation and goal-directed behavior, is a common yet often overlooked multidimensional psychopathological state in schizophrenia. Its underlying cognitive processes remain largely unexplored. Data was drawn from a longitudinal hospital study of patients with a DSM-IV diagnosis of schizophrenia; 137 (82.5%) participated at the 1-month follow-up and 81 (59.1%) at the 1-year follow-up. Apathy was assessed with the Lille Apathy Rating Scale, validated in French and in schizophrenia. Severe apathy, overall (total score > -13) and on 4 previously identified distinct dimensions, was considered. Episodic verbal learning was assessed with the California Verbal Learning Test, executive functioning with the Trail Making Test, the Six Element Test and the Stop Signal Paradigm and working memory with the Letter-Number Sequencing Test. After controlling for confounding variables, only episodic verbal learning was associated with severe overall apathy in the cross-sectional study. At 1 year, working memory was associated with an increased risk of severe overall apathy, adjusting for baseline apathy. Using a dimensional approach to apathy, specific types of cognition were found to be associated with specific dimensions of apathy. Our findings confirm the need for a multidimensional approach of negative symptoms in schizophrenia. Moreover, cognitive functioning could be a risk factor for developing severe apathy. Cognitive remediation may thus be a useful non-pharmacological intervention for treating apathy in schizophrenia patients.

  15. Use of the AngioSculpt scoring balloon for infrapopliteal lesions in patients with critical limb ischemia: 1-year outcome.

    PubMed

    Bosiers, Marc; Deloose, Koen; Cagiannos, Catherine; Verbist, Jürgen; Peeters, Patrick

    2009-01-01

    The AngioSculpt Scoring Balloon Catheter (AngioScore, Inc., Fremont, CA) is composed of a semicompliant balloon encircled by three nitinol spiral struts providing targeted lesion scoring on balloon inflation. Between April 2005 and April 2006, procedural and follow-up data on 31 patients (mean age 76 years; 54.8% males) endovascularly treated for severe infrapopliteal disease were collected. The AngioSculpt catheter was used to treat 36 complex, tibioperoneal, atherosclerotic lesions. All patients had symptomatic critical limb ischemia (Rutherford 4-5) and single-vessel runoff to the ankle. Complication-free survival at 1 month was the safety end point, whereas primary patency and limb salvage were the efficacy end points evaluated at 1 year. The AngioSculpt balloon was successfully inflated in all 36 target lesions. Eleven patients (35.5%) required additional stenting for minor dissections or suboptimal stenosis reduction. The 1-month complication-free survival was 96.8%. One-year survival, primary patency, and limb salvage rates were 83.9 +/- 6.6%, 61.0 +/- 9.3%, and 86.3 +/- 6.4%, respectively. The 1-year data show the AngioSculpt Scoring Balloon Catheter to be an effective and safe treatment for infrapopliteal, atherosclerotic lesions in patients with critical limb ischemia. However, more patients, a longer follow-up, and randomized studies comparing it with conventional balloon angioplasty and stenting in the infrapopliteal region are required.

  16. Management and 1-year outcomes of patients with atrial fibrillation in the Middle East: Gulf survey of atrial fibrillation events.

    PubMed

    Zubaid, Mohammad; Rashed, Wafa A; Alsheikh-Ali, Alawi A; Al-Zakwani, Ibrahim; AlMahmeed, Wael; Shehab, Abdullah; Sulaiman, Kadhim; Qudaimi, Ahmed Al; Asaad, Nidal; Amin, Haitham

    2015-05-01

    We describe management and outcomes of patients with nonvalvular atrial fibrillation (AF) in the Middle East. Consecutive patients with AF presenting to emergency departments (EDs) were prospectively enrolled. Among 1721 patients with nonvalvular AF, mean age was 59 ± 16 years and 44% were women. Comorbidities were common such as hypertension (59%), diabetes (33%), and coronary artery disease (33%). Warfarin was not prescribed to 40% of patients with Congestive heart failure, Hypertension, Age, Diabetes mellitus, Stroke/TIA2 score of ≥2. One-year rates of stroke/transient ischemic attack (TIA) and all-cause mortality were 4.2% and 15.3%, respectively. Warfarin use at hospital-ED discharge was independently associated with lower 1-year rate of stroke/TIA (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.17-0.85; P = .015) and all-cause mortality (OR, 0.51; 95% CI, 0.32-0.83; P = .006). Prior history of heart failure and peripheral vascular disease was independent mortality predictors. Our patients are relatively young with significant cardiovascular risk. Their anticoagulation treatment is suboptimal, and 1-year all-cause mortality and stroke/TIA event rates are relatively high.

  17. Cognitive function, social functioning and quality of life in first-episode psychosis: A 1-year longitudinal study.

    PubMed

    Popolo, Raffaele; Vinci, Giancarlo; Balbi, Andrea

    2010-03-01

    Abstract Objective. The majority of patients with schizophrenia have cognitive deficits early in the disease. We evaluated the relationship between cognitive function, social functioning and quality of life in patients with first-episode psychosis. Methods. This was a longitudinal study in 15 patients aged 18-30 years who had recently experienced a first psychotic episode and were treated with the atypical antipsychotic aripiprazole, cognitive-behavioural therapy, psycho-educational sessions, family supportive sessions and social interventions. Patients were evaluated at baseline and after 1 year. Cognitive assessment included attention, memory, language skills and problem solving. Social functioning, quality of life, and psychopathological evaluation were performed with validated tools. Results. At baseline, patients had a severe impairment of social functioning and a low quality of life, while a specific pattern of cognitive functions was not identified. After 1-year, we observed a significant improvement in social functioning and quality of life, without a significant decrease in cognitive function. Conclusion. Contrary to previous findings, we found that social functioning and quality of life are related, but independent of cognitive impairment. The use of antipsychotic agents that do not interefere with cognitive function plus psychological assistance is a valuable treatment approach in patients with first-episode schizophrenia.

  18. MRI of knee ligament injury and reconstruction.

    PubMed

    Farshad-Amacker, Nadja A; Potter, Hollis G

    2013-10-01

    Knee ligament instability may lead to meniscal and chondral damage, resulting in early osteoarthritis. Due to its superior soft tissue contrast and avoidance of harmful ionizing radiation, MRI has become the most important imaging modality for early recognition of structural defects of the knee joint. This review aims to the understanding of MRI appearances of knee ligament structures associated with knee instability, and to review the common patterns of altered knee mechanics that lead to ligament failure. Normal anatomy of the knee ligaments, pathologic conditions, and postsurgical appearances of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, and posterolateral corner are described.

  19. Stem Cell Therapy: MRI Guidance and Monitoring

    PubMed Central

    Kraitchman, Dara L.; Gilson, Wesley D.; Lorenz, Christine H.

    2011-01-01

    With the recent advances in magnetic resonance (MR) labeling of cellular therapeutics, it is natural that interventional MRI techniques for targeting would be developed. This review provides an overview of the current methods of stem cell labeling and the challenges that are created with respect to interventional MRI administration. In particular, stem cell therapies will require specialized, MR-compatible devices as well as integration of graphical user interfaces with pulse sequences designed for interactive, real-time delivery in many organs. Specific applications that are being developed will be reviewed as well as strategies for future translation to the clinical realm. PMID:18219684

  20. Practical MRI atlas of neonatal brain development

    SciTech Connect

    Barkovich, A.J.; Truwit, C.L.

    1990-01-01

    This book is an anatomical reference for cranial magnetic resonance imaging (MRI) studies in neonates and infants. It contains 122 clear, sharp MRI scans and drawings showing changes in the normal appearance of the brain and skull during development. Sections of the atlas depict the major processes of maturation: brain myelination, development of the corpus callosum, development of the cranial bone marrow, and iron deposition in the brain. High-quality scans illustrate how these changes appear on magnetic resonance images during various stages of development.