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Wei-Yuan Huang, Gang Wu, Shan-Xi Guo, Dao-Ying Geng, Jian-Jun Li, Kai Yang
The aim of the study is to verify the effect of hyperglycemia on ischemia-reperfusion injury and to explore the feasibility of noninvasive observation of ischemic-reperfusion injury in hyperglycemic ischemic stroke by MRI technique. According to the duration of ischemia and blood glucose levels, 40 rats were divided into hyperglycemic ischemic 2-hr (H-I2h), hyperglycemic ischemic 6-hr (H-I6h), non- hyperglycemic ischemic 2-hr (NH-I2h), and non- hyperglycemic ischemic 6-hr (NH-I6h) groups. T2W imaging, DW imaging, T2 mapping, T2* mapping, DCE, and T1 mapping after enhancement sequences were acquired before reperfusion and approximately 3-hr after reperfusion...
February 27, 2019: Scientific Reports
Junliang Yuan, Li Feng, Wenli Hu, Yumei Zhang
Leukoaraiosis, also referred to as white-matter hyperintensities (WMHs) or age-related white matter changes, is the most frequently seen lesion on brain magnetic resonance images (MRI) in the elderly. LA is a subject of intense research interest, and is correlated with stroke, cognitive impairment or dementia, disturbances, affective disorders, and poor prognoses. Rapid advances in neuroimaging have enabled greater understanding of LA associated with aging-related cognitive decline or dementia. Recently, the techniques of multimodal MRI, such as structural MRI (sMRI), resting-state functional MRI (rs-MRI), cerebrovascular reactivity (CVR), diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), and dynamic contrast-enhanced MRI (DCE-MRI), have been used to explore the underlying mechanism of cognitive impairment in patients with LA...
December 9, 2018: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
C Chad Quarles, Laura C Bell, Ashley M Stokes
In the context of neurologic disorders, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI provide valuable insights into cerebral vascular function, integrity, and architecture. Even after two decades of use, these modalities continue to evolve as their biophysical and kinetic basis is better understood, with improvements in pulse sequences and accelerated imaging techniques and through application of more robust and automated data analysis strategies. Here, we systematically review each of these elements, with a focus on how their integration improves kinetic parameter accuracy and the development of new hemodynamic biomarkers that provide sub-voxel sensitivity (e...
May 3, 2018: NeuroImage
Yirong Yang, Lisa Y Yang, Lilla Orban, Darnell Cuylear, Jeffrey Thompson, Bruce Simon, Yi Yang
BACKGROUND: Vagus nerve stimulation (VNS) significantly reduces infarct volume in rat models of cerebral ischemia, but the mechanism of this protective effect remains open. HYPOTHESIS: This study tested the hypothesis that non-invasive VNS (nVNS), during transient middle cerebral artery occlusion (MCAO), protects the blood-brain barrier (BBB), leading to reduced infarct size in ischemic brain. METHODS: Spontaneous hypertensive rats (SHRs) were subjected to a 90 min MCAO...
July 2018: Brain Stimulation
Raf H M van Hoof, Floris H B M Schreuder, Patty Nelemans, Martine T B Truijman, Narender P van Orshoven, Tobien H Schreuder, Werner H Mess, Sylvia Heeneman, Robert J van Oostenbrugge, Joachim E Wildberger, M Eline Kooi
BACKGROUND: Patients with a recent ischemic stroke have a higher risk of recurrent stroke compared to (ocular) transient ischemic attack (TIA) patients. Plaque microvasculature is considered as a feature of plaque vulnerability and can be quantified with carotid dynamic contrast-enhanced MRI (DCE-MRI). The purpose of this cross-sectional study was to explore the association between plaque microvasculature and the type of recent cerebrovascular events in symptomatic patients with mild-to-moderate carotid stenosis...
2017: Cerebrovascular Diseases
Zamir Merali, Kun Huang, David Mikulis, Frank Silver, Andrea Kassner
The dynamics of BBB permeability after AIS in humans are not well understood. In the present study we measured the evolution of BBB permeability after AIS in humans using MRI. Patients presenting to our institution with a diagnosis of AIS underwent a single dynamic contrast-enhanced MRI (DCE-MRI) sequence to measure BBB permeability during their initial workup. Forty-two patients were included in the final analysis. The patient sample underwent DCE-MRI at a mean time of 23.8hrs after the onset of AIS symptoms (range: 1...
2017: PloS One
Kersten Villringer, Borja E Sanz Cuesta, Ann-Christin Ostwaldt, Ulrike Grittner, Peter Brunecker, Ahmed A Khalil, Kristina Schindler, Ole Eisenblätter, Heinrich Audebert, Jochen B Fiebach
OBJECTIVE: To quantitatively evaluate blood-brain barrier changes in ischemic stroke patients using dynamic contrast-enhanced (DCE) MRI. METHODS: We examined 54 stroke patients ( NCT00715533, NCT02077582) in a 3T MRI scanner within 48 hours after symptom onset. Twenty-eight patients had a follow-up examination on day 5-7. DCE T1 mapping and Patlak analysis were employed to assess BBB permeability changes. RESULTS: Median stroke K(trans) values (0...
January 31, 2017: Neurology
Guy Nadav, Gilad Liberman, Moran Artzi, Nahum Kiryati, Dafna Ben Bashat
PURPOSE: To optimize the analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) under the two-compartment-exchange-model (2CXM) and to incorporate voxelwise bolus-arrival-time (BAT). MATERIALS AND METHODS: The accuracy of the pharmacokinetic (PK) parameters, extracted from 3T DCE-MRI using 2CXM, was tested under several conditions: eight algorithms for data estimation; correction for BAT; using model selection; different temporal resolution and scan duration...
January 2017: Journal of Magnetic Resonance Imaging: JMRI
Wei-Yuan Huang, Gang Wu, Jian-Jun Li, Dao-Ying Geng, Wen-Li Tan, Xiang-Rong Yu
BACKGROUND AND PURPOSE: Early prediction of functional outcome in cerebral ischemia stroke using MRI remains a challenge. The aim of this study was to evaluate the predictive value of dynamic contrast-enhanced (DCE) MRI in terms of functional outcome of ischemia stroke. METHODS: Right middle cerebral artery occlusion (MCAO) was performed in male SD rats (n=50), followed by withdrawal of the occluding filament after 3 (n = 10), 4 (n = 10), 5 (n = 10), 6 (n = 10) or 7 (n = 10) h to establish ischemia and reperfusion stroke...
September 2016: Magnetic Resonance Imaging
Raf H M van Hoof, Sylvia Heeneman, Joachim E Wildberger, M Eline Kooi
Rupture of a vulnerable atherosclerotic plaque of the carotid artery is an important underlying cause of clinical ischemic events, such as stroke. Abundant microvasculature has been identified as an important aspect contributing to plaque vulnerability. Plaque microvasculature can be studied non-invasively with dynamic contrast-enhanced (DCE-)MRI in animals and patients. In recent years, several DCE-MRI studies have been published evaluating the association between microvasculature and other key features of plaque vulnerability (e...
June 2016: Current Atherosclerosis Reports
Frank G Zöllner, Markus Daab, Steven P Sourbron, Lothar R Schad, Stefan O Schoenberg, Gerald Weisser
BACKGROUND: Perfusion imaging has become an important image based tool to derive the physiological information in various applications, like tumor diagnostics and therapy, stroke, (cardio-) vascular diseases, or functional assessment of organs. However, even after 20 years of intense research in this field, perfusion imaging still remains a research tool without a broad clinical usage. One problem is the lack of standardization in technical aspects which have to be considered for successful quantitative evaluation; the second problem is a lack of tools that allow a direct integration into the diagnostic workflow in radiology...
January 14, 2016: BMC Medical Imaging
Gilad Liberman, Yoram Louzoun, Moran Artzi, Guy Nadav, James R Ewing, Dafna Ben Bashat
Dynamic contrast enhanced (DCE) MRI using Tofts' model for estimating vascular permeability is widely accepted, yet inter-tissue differences in bolus arrival time (BAT) are generally ignored. In this work we propose a method, incorporating the BAT in the analysis, demonstrating its applicability and advantages in healthy subjects and patients. A method for DCE Up Sampled TEmporal Resolution (DUSTER) analysis is proposed which includes: baseline T1 map using DESPOT1 analyzed with flip angle (FA) correction; preprocessing; raw-signal-to-T1-to-concentration time curves (CTC) conversion; automatic arterial input function (AIF) extraction at temporal super-resolution; model fitting with model selection while incorporating BAT in the pharmacokinetic (PK) model, and fits contrast agent CTC while using exhaustive search in the BAT dimension in super-resolution...
May 2016: Magnetic Resonance Imaging
Anna K Heye, Michael J Thrippleton, Paul A Armitage, Maria Del C Valdés Hernández, Stephen D Makin, Andreas Glatz, Eleni Sakka, Joanna M Wardlaw
There is evidence that subtle breakdown of the blood-brain barrier (BBB) is a pathophysiological component of several diseases, including cerebral small vessel disease and some dementias. Dynamic contrast-enhanced MRI (DCE-MRI) combined with tracer kinetic modelling is widely used for assessing permeability and perfusion in brain tumours and body tissues where contrast agents readily accumulate in the extracellular space. However, in diseases where leakage is subtle, the optimal approach for measuring BBB integrity is likely to differ since the magnitude and rate of enhancement caused by leakage are extremely low; several methods have been reported in the literature, yielding a wide range of parameters even in healthy subjects...
January 15, 2016: NeuroImage
Claudia Calcagno, Mark E Lobatto, Hadrien Dyvorne, Philip M Robson, Antoine Millon, Max L Senders, Olivier Lairez, Sarayu Ramachandran, Bram F Coolen, Alexandra Black, Willem J M Mulder, Zahi A Fayad
Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI studies of atherosclerosis have been limited to two-dimensional (2D) multi-slice imaging. Although providing the high spatial resolution required to image the arterial vessel wall, these approaches do not allow the quantification of plaque permeability with extensive anatomical coverage, an essential feature when imaging heterogeneous diseases, such as atherosclerosis...
October 2015: NMR in Biomedicine
Hyun Seok Choi, Sung Soo Ahn, Na-Young Shin, Jinna Kim, Jae Hyung Kim, Jong Eun Lee, Hye Yeon Lee, Ji Hoe Heo, Seung-Koo Lee
OBJECTIVE: The purpose of this study was to correlate permeability parameters measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a clinical 3-tesla scanner with extravasation of Evans blue in a rat model with transient cerebral ischemia. MATERIALS AND METHODS: Sprague-Dawley rats (n = 13) with transient middle cerebral artery occlusion were imaged using a 3-tesla MRI with an 8-channel wrist coil. DCE-MRI was performed 12 hours, 18 hours, and 36 hours after reperfusion...
July 2015: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
Zamir Merali, Teser Wong, Jackie Leung, Meah MingYang Gao, David Mikulis, Andrea Kassner
In the current management of acute ischemic stroke (AIS), clinical criteria are used to estimate the risk of hemorrhagic transformation (HT), which is a devastating early complication. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and computed tomography (DCE-CT) may serve as physiologically-based decision making tools to more reliably assess the risk of HT. Before these tools can be properly validated, the comparability of the blood-brain barrier (BBB) permeability measurements they generate should be assessed...
October 2015: Magnetic Resonance Imaging
Anna K Heye, Ross D Culling, Maria Del C Valdés Hernández, Michael J Thrippleton, Joanna M Wardlaw
There is increasing recognition of the importance of blood-brain barrier (BBB) disruption in aging, dementia, stroke and multiple sclerosis in addition to more commonly-studied pathologies such as tumors. Dynamic contrast-enhanced MRI (DCE-MRI) is a method for studying BBB disruption in vivo. We review pathologies studied, scanning protocols and data analysis procedures to determine the range of available methods and their suitability to different pathologies. We systematically review the existing literature up to February 2014, seeking studies that assessed BBB integrity using T1-weighted DCE-MRI techniques in animals and humans in normal or abnormal brain tissues...
2014: NeuroImage: Clinical
N D Forkert, B Cheng, A Kemmling, G Thomalla, J Fiehler
OBJECTIVES: The objective of this work is to present the software tool ANTONIA, which has been developed to facilitate a quantitative analysis of perfusion-weighted MRI (PWI) datasets in general as well as the subsequent multi-parametric analysis of additional datasets for the specific purpose of acute ischemic stroke patient dataset evaluation. METHODS: Three different methods for the analysis of DSC or DCE PWI datasets are currently implemented in ANTONIA, which can be case-specifically selected based on the study protocol...
2014: Methods of Information in Medicine
Yaron Gordon, Sasan Partovi, Matthias Müller-Eschner, Erick Amarteifio, Tobias Bäuerle, Marc-André Weber, Hans-Ulrich Kauczor, Fabian Rengier
INTRODUCTION: The ability to ascertain information pertaining to peripheral perfusion through the analysis of tissues' temporal reaction to the inflow of contrast agent (CA) was first recognized in the early 1990's. Similar to other functional magnetic resonance imaging (MRI) techniques such as arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) MRI, dynamic contrast-enhanced MRI (DCE-MRI) was at first restricted to studies of the brain. Over the last two decades the spectrum of ailments, which have been studied with DCE-MRI, has been extensively broadened and has come to include pathologies of the heart notably infarction, stroke and further cerebral afflictions, a wide range of neoplasms with an emphasis on antiangiogenic treatment and early detection, as well as investigations of the peripheral vascular and musculoskeletal systems...
April 2014: Cardiovascular Diagnosis and Therapy
M Bergamino, L Bonzano, F Levrero, G L Mancardi, L Roccatagliata
In the last few years, several imaging methods, such as magnetic resonance imaging (MRI) and computed tomography, have been used to investigate the degree of blood-brain barrier (BBB) permeability in patients with neurological diseases including multiple sclerosis, ischemic stroke, and brain tumors. One promising MRI method for assessing the BBB permeability of patients with neurological diseases in vivo is T1-weighted dynamic contrast-enhanced (DCE)-MRI. Here we review the technical issues involved in DCE-MRI in the study of human brain tumors...
September 2014: Physica Medica: PM
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