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https://www.readbyqxmd.com/read/29226283/improving-functional-mri-registration-using-whole-brain-functional-correlation-tensors
#1
Yujia Zhou, Pew-Thian Yap, Han Zhang, Lichi Zhang, Qianjin Feng, Dinggang Shen
Population studies of brain function with resting-state functional magnetic resonance imaging (rs-fMRI) largely rely on the accurate inter-subject registration of functional areas. This is typically achieved through registration of the corresponding T1-weighted MR images with more structural details. However, accumulating evidence has suggested that such strategy cannot well-align functional regions which are not necessarily confined by the anatomical boundaries defined by the T1-weighted MR images. To mitigate this problem, various registration algorithms based directly on rs-fMRI data have been developed, most of which have utilized functional connectivity (FC) as features for registration...
September 2017: Medical Image Computing and Computer-assisted Intervention: MICCAI ..
https://www.readbyqxmd.com/read/29217405/a-novel-perspective-to-calibrate-temporal-delays-in-cerebrovascular-reactivity-using-hypercapnic-and-hyperoxic-respiratory-challenges
#2
Allen A Champagne, Alex A Bhogal, Nicole S Coverdale, Clarisse I Mark, Douglas J Cook
Redistribution of blood flow across different brain regions, arising from the vasoactive nature of hypercapnia, can introduce errors when examining cerebrovascular reactivity (CVR) response delays. In this study, we propose a novel analysis method to characterize hemodynamic delays in the blood oxygen level dependent (BOLD) response to hypercapnia, and hyperoxia, as a way to provide insight into transient differences in vascular reactivity between cortical regions, and across tissue depths. A pseudo-continuous arterial spin labeling sequence was used to acquire BOLD and cerebral blood flow simultaneously in 19 healthy adults (12 F; 20 ± 2 years) during boxcar CO2 and O2 gas inhalation paradigms...
December 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/29208571/using-multi-echo-simultaneous-multi-slice-sms-epi-to-improve-functional-mri-of-the-subcortical-nuclei-of-the-basal-ganglia-at-ultra-high-field-7t
#3
Alexander M Puckett, Saskia Bollmann, Benedikt A Poser, Jake Palmer, Markus Barth, Ross Cunnington
The nuclei of the basal ganglia pose a special problem for functional MRI, especially at ultra-high field, because T2* variations between different regions result in suboptimal BOLD sensitivity when using gradient-echo echo-planar imaging (EPI). Specifically, the iron-rich lentiform nucleus of the basal ganglia, including the putamen and globus pallidus, suffers from substantial signal loss when imaging is performed using conventional single-echo EPI with echo times (TE) optimized for the cortex. Multi-echo EPI acquires several echoes at different echo times for every imaging slice, allowing images to be reconstructed with a weighting of echo times that is optimized individually for each voxel according to the underlying tissue or T2* properties...
December 2, 2017: NeuroImage
https://www.readbyqxmd.com/read/29197870/detection-of-acute-tubular-necrosis-using-blood-oxygenation-level-dependent-bold-mri
#4
Frederic Bauer, Jan Wald, Felix Jan Bauer, Lisa Maria Dahlkamp, Felix S Seibert, Nikolaos Pagonas, Egbert Gedat, Nina Babel, Walter Zidek, Christian von Bodman, Joachim Noldus, Dieter Liermann, Timm H Westhoff
BACKGROUND/AIMS: To date, there is no imaging technique to assess tubular function in vivo. Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) measures tissue oxygenation based on the transverse relaxation rate (R2*). The present study investigates whether BOLD MRI can assess tubular function using a tubule-specific pharmacological maneuver. METHODS: Cross sectional study with 28 participants including 9 subjects with ATN-induced acute kidney injury (AKI), 9 healthy controls, and 10 subjects with nephron sparing tumor resection (NSS) with clamping of the renal artery serving as a model of ischemia/reperfusion (I/R)-induced subclinical ATN (median clamping time 15 min, no significant decrease of eGFR, p=0...
December 4, 2017: Kidney & Blood Pressure Research
https://www.readbyqxmd.com/read/29176647/mri-simulation-study-investigating-effects-of-vessel-topology-diffusion-and-susceptibility-on-transverse-relaxation-rates-using-a-cylinder-fork-model
#5
Mohammed Salman Shazeeb, Jayashree Kalpathy-Cramer, Bashar Issa
Brain vasculature is conventionally represented as straight cylinders when simulating blood oxygenation level dependent (BOLD) contrast effects in functional magnetic resonance imaging (fMRI). In reality, the vasculature is more complicated with branching and coiling especially in tumors. Diffusion and susceptibility changes can also introduce variations in the relaxation mechanisms within tumors. This study introduces a simple cylinder fork model (CFM) and investigates the effects of vessel topology, diffusion, and susceptibility on the transverse relaxation rates R2* and R2...
November 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29163072/altered-functional-brain-connectomes-between-sporadic-and-familial-parkinson-s-patients
#6
Yan Tang, Xue Xiao, Hua Xie, Chang-Min Wan, Li Meng, Zhen-Hua Liu, Wei-Hua Liao, Bei-Sha Tang, Ji-Feng Guo
Familial Parkinson's disease (PD) is often caused by mutation of a certain gene, while sporadic PD is associated with variants of genes which can influence the susceptibility to PD. The goal of this study was to investigate the difference between the two forms of PD in terms of brain abnormalities using resting-state functional MRI and graph theory. Thirty-one familial PD patients and 36 sporadic PD patients underwent resting-state functional MRI scanning. Frequency-dependent functional connectivity was calculated for each subject using wavelet-based correlations of BOLD signal over 246 brain regions from Brainnetome Atlas...
2017: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/29160088/resting-state-functional-connectivity-of-the-subthalamic-nucleus-to-limbic-associative-and-motor-networks
#7
Sheeba Arnold Anteraper, Xavier Guell, Susan Whitfield-Gabrieli, Christina Triantafyllou, Aaron Mattfeld, John D Gabrieli, Maiya Geddes
The subthalamic nucleus (STN) is a small structure situated deep in the mid-brain that exhibits wide-ranging functionality. In addition to its role in motor control, the STN is considered a hub for synchronizing aspects of emotion and cognition including attention, inhibitory control, motivation, and working memory. Evidence from neuroanatomical tracer studies suggests that the medial, ventromedial, and dorsolateral parts of the STN correspond to limbic, associative, and motor subdivisions respectively. While the extent of STN functional anatomical overlap remains unclear, BOLD imaging of the STN may provide complementary information about the diverse functions of this structure...
November 21, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/29159960/mapping-the-structural-and-functional-network-architecture-of-the-medial-temporal-lobe-using-7t-mri
#8
Preya Shah, Danielle S Bassett, Laura E M Wisse, John A Detre, Joel M Stein, Paul A Yushkevich, Russell T Shinohara, John B Pluta, Elijah Valenciano, Molly Daffner, David A Wolk, Mark A Elliott, Brian Litt, Kathryn A Davis, Sandhitsu R Das
Medial temporal lobe (MTL) subregions play integral roles in memory function and are differentially affected in various neurological and psychiatric disorders. The ability to structurally and functionally characterize these subregions may be important to understanding MTL physiology and diagnosing diseases involving the MTL. In this study, we characterized network architecture of the MTL in healthy subjects (n = 31) using both resting state functional MRI and MTL-focused T2-weighted structural MRI at 7 tesla...
November 20, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29154684/brain-functional-connectivity-in-headache-disorders-a-narrative-review-of-mri-investigations
#9
Catherine D Chong, Todd J Schwedt, Anders Hougaard
Resting-state functional magnetic resonance imaging (rs-fMRI) is used to interrogate the functional connectivity and network organization amongst brain regions. Functional connectivity is determined by measuring the extent of synchronization in the spontaneous fluctuations of blood oxygenation level dependent (BOLD) signal. Here, we review current rs-fMRI studies in headache disorders including migraine, trigeminal autonomic cephalalgias, and medication overuse headache. We discuss (1) brain network alterations that are shared amongst the different headache disorders and (2) network abnormalities distinct to each headache disorder...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29152994/decreased-connectivity-and-increased-bold-complexity-in-the-default-mode-network-in-individuals-with-chronic-fatigue-syndrome
#10
Zack Y Shan, Kevin Finegan, Sandeep Bhuta, Timothy Ireland, Donald R Staines, Sonya M Marshall-Gradisnik, Leighton R Barnden
The chronic fatigue syndrome / myalgic encephalomyelitis (CFS) is a debilitating disease with unknown pathophysiology and no diagnostic test. This study investigated the default mode network (DMN) in order to understand the pathophysiology of CFS and to identify potential biomarkers. Using functional MRI (fMRI) collected from 72 subjects (45 CFS and 27 controls) with a temporal resolution of 0.798s, we evaluated the default mode network using static functional connectivity (FC), dynamic functional connectivity (DFC) and DFC complexity, blood oxygenation level dependent (BOLD) activation maps and complexity of activity...
November 20, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/29143414/central-pain-processing-in-drug-na%C3%A3-ve-pain-free-patients-with-parkinson-s-disease
#11
Alessandro Tessitore, Antonio Russo, Rosa De Micco, Michele Fratello, Giuseppina Caiazzo, Alfonso Giordano, Mario Cirillo, Gioacchino Tedeschi, Fabrizio Esposito
BACKGROUND: Despite its clinical relevance, the pathophysiology of pain in Parkinson's disease (PD) is still largely unknown, and both central and peripheral mechanisms have been invoked. OBJECTIVES: To investigate whether central pain processing is altered in "drug-naive" pain-free PD (dnPD) patients. METHODS: Using event-related functional MRI (fMRI), functional response to forearm heat stimulation (FHS) at two different intensities (41°C and 53°C) was investigated in 20 pain-free dnPD patients, compared with 18 healthy controls (HCs)...
November 15, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29130510/heterogenous-migraine-aura-symptoms-correlate-with-visual-cortex-fmri-responses
#12
Nanna Arngrim, Anders Hougaard, Khazar Ahmadi, Mark Bitsch Vestergaard, Henrik Winther Schytz, Faisal Mohammad Amin, Henrik Bo Wiberg Larsson, Jes Olesen, Michael B Hoffmann, Messoud Ashina
OBJECTIVE: Migraine aura is sparsely studied due to the highly challenging task of capturing patients during aura. Cortical spreading depression (CSD) is likely the underlying phenomenon of aura. The possible correlation between the multifaceted phenomenology of aura symptoms and the effects of CSD on the brain has not been ascertained. METHODS: Five migraine patients were studied during various forms of aura symptoms induced by hypoxia, sham or physical exercise and photostimulation...
November 11, 2017: Annals of Neurology
https://www.readbyqxmd.com/read/29121642/limbic-system-damage-in-ms-mri-assessment-and-correlations-with-clinical-testing
#13
Jie Wen, Dmitriy A Yablonskiy, Amber Salter, Anne H Cross
Volume loss in some limbic region structures has been observed in multiple sclerosis (MS) patients. However, in vivo evaluation of existing tissue cellular microstructure integrity has received less attention. The goal of studies reported here was to quantitatively assess loss of limbic system volumes and tissue integrity, and to evaluate associations of these measures with cognitive and physical dysfunction in MS patients. Thirty-one healthy controls (HC) and 80 MS patients, including 32 relapsing remitting (RRMS), 32 secondary progressive (SPMS) and 16 primary progressive (PPMS), participated in this study...
2017: PloS One
https://www.readbyqxmd.com/read/29117709/detecting-perfusion-pattern-based-on-the-background-low-frequency-fluctuation-in-resting-state-functional-mri-data-and-its-influence-on-resting-state-networks-an-iterative-post-processing-approach
#14
Tianyi Qian, Davide Zanchi, Cristelle Rodriguez, Marine Ackermann, Panteleimon Giannakopoulos, Sven Haller
INTRODUCTION: RS-fMRI is based on the assumption that the vascular response and the blood oxygenation level dependent (BOLD) response are homogenous across the entire brain. However, this a priori hypothesis is not consistent with the well-known variability of cerebral vascular territories. In order to explore whether the RS networks are influenced by varied vascular speed in different vascular territories, we assessed the time-shift maps that give an estimate of the local timing of the vascular response and check whether local differences in this timing have an impact on the estimates of RS networks...
November 8, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/29113406/altered-dmn-functional-connectivity-and-regional-homogeneity-in-partial-epilepsy-patients-a-seventy-cases-study
#15
Chong-Yu Hu, Xiaoping Gao, Lili Long, Xiaoyan Long, Chaorong Liu, Yayu Chen, Yuanyuan Xie, Chujuan Liu, Bo Xiao, Zhe-Yu Hu
Purpose: Clinically diagnosed partial epilepsy is hard to be functionally diagnosed by regular electroencephalograph (EEG) and conventional magnetic resonance imaging (MRI). By collecting transient brain regional signals, blood oxygenation level-dependent (BOLD) function MRI (BOLD-fMRI) can provide brain function change information with high accuracy. By using resting state BOLD-fMRI technique, we aim to investigate the changes of brain function in partial epilepsy patients. Methods: BOLD-fMRI scanning was performed in 70 partial epilepsy and 70 healthy people...
October 6, 2017: Oncotarget
https://www.readbyqxmd.com/read/29095269/bold-mri-early-detect-femoral-head-osteonecrosis-following-steroid-treated-patients
#16
Jing Li, Jingjing Wang, Jihua Zhao, Bin Yuan, Liming Xing, Fengming Tang, Lei Liu, Mingming Lu, Quan Zhang, Jun Zhao, Peng Gu, Jianhui Li, Zhuoli Zhang, Chong Sun, Yu Zhang, Fei Yuan
The purpose of the study is to evaluate the feasibility of blood oxygenation level-dependent MRI (BOLD-MRI) to early detect the femoral head osteonecrosis (FHON). One hundred twelve patients were recruited who had received steroid treatment. The normal control group included 10 volunteers with 20 hips. MRI examinations were performed in all patients following up at 1, 4 to 5, 7 to 8, and 12 to 13 months after steroid therapy. With the section cross as the biggest lesion in coronal images, we set 6 regions of interest (ROIs) per section to analyze the morphological performance of routine MRI sequences and the differences of R2* values and their dynamic changes of BOLD-MRI between the control and the FHON group...
November 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29079138/a-homer-1-gene-variant-influences-brain-structure-and-function-lithium-effects-on-white-matter-and-antidepressant-response-in-bipolar-disorder-a-multimodal-genetic-imaging-study
#17
Francesco Benedetti, Sara Poletti, Clara Locatelli, Elena Mazza, Cristina Lorenzi, Alice Vitali, Martina Riberto, Silvia Brioschi, Benedetta Vai, Irene Bollettini, Elisa Melloni, Veronica Aggio, Andrea Falini, Andrea De Bartolomeis, Cristina Colombo
BACKGROUND: The Homer family of postsynaptic scaffolding proteins plays a crucial role in glutamate-mediated synaptic plasticity, a phenotype associated with Bipolar Disorder (BD). Homer is a target for antidepressants and mood stabilizers. The AA risk genotype of the Homer rs7713917 A>G SNP has been associated with mood disorders and suicide, and in healthy humans with brain function. Despite the evidence linking Homer 1 gene and function to mood disorder, as well as its involvement in animal models of depression, no study has yet investigated the role of Homer in bipolar depression and treatment response...
February 2, 2018: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/29065769/imaging-of-cerebrovascular-function-in-chronic-traumatic-brain-injury
#18
Franck Amyot, Kimbra Kenney, Carol Moore, Maraglit Harber, L Christine Turtzo, Christian N Shenouda, Erika Silverman, Yunhua Gong, Bao-Xi Qu, Leah Harburg, Hangzang Lu, Eric Wassermann, Ramon Diaz-Arrastia
Traumatic cerebrovascular injury (TCVI) is a common pathologic mechanism of traumatic brain injury (TBI) and presents an attractive target for intervention. The aims of this study were to assess cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) using magnetic resonance imaging (MRI), to assess their value as biomarkers of TCVI in chronic TBI, characterize the spatial distribution of TCVI, and assess the relationships between each biomarker and neuropsychological and clinical assessments. 42 subjects (27 chronic TBI, 15 age and gender-matched healthy volunteers) were studied cross-sectionally...
October 25, 2017: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29063424/assessing-renal-changes-after-remote-ischemic-preconditioning-ripc-of-the-upper-extremity-using-bold-imaging-at-3t
#19
Florian Siedek, Thorsten Persigehl, Roman-Ulrich Mueller, Volker Burst, Thomas Benzing, David Maintz, Stefan Haneder
OBJECTIVE: Acute kidney injury (AKI) is an important risk factor for a number of adverse outcomes including end-stage renal disease and cardiovascular morbidity and mortality. Whilst many clinical situations that can induce AKI are known-e.g. drug toxicity, contrast agent exposure or ischemia during surgery-targeted preventive or therapeutic measures are still lacking. As to renoprotective strategies, remote ischemic preconditioning (RIPC) is one of the most promising novel approaches and has been examined by a number of clinical trials...
October 23, 2017: Magma
https://www.readbyqxmd.com/read/29061514/bold-mri-demonstrates-acute-placental-and-fetal-organ-hypoperfusion-with-fetal-brain-sparing-during-hypercapnia
#20
Yehuda Ginosar, Yuval Gielchinsky, Nathalie Nachmansson, Lital Hagai, Joel Shapiro, Uriel Elchalal, Rinat Abramovitch
INTRODUCTION: We evaluated changes in placental and fetal hemodynamics in rodents during acute hypercapnia using BOLD-MRI and Doppler ultrasound. METHODS: Animals were anesthetized with pentobarbital and, in consecutive 4-min periods, breathed: air, 21%O2:5%CO2, and 95%O2:5%CO2. BOLD-MRI: Pregnant ICR mice (n = 6; E17.5) were scanned in a 4.7-T Bruker Biospec spectrometer. Placenta and fetal liver, heart and brain were identified on True-FISP images...
September 11, 2017: Placenta
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