Abstract:
:In pharmacological magnetic resonance imaging (phMRI) with anesthetized animals, there is usually only a single time window to observe the dynamic signal change to an acute drug administration since subsequent drug injections are likely to result in altered response properties (e.g., tolerance). Unlike the block-design experiments in which fMRI signal can be elicited with multiple repetitions of a task, these single-event experiments require stable baseline in order to reliably identify drug-induced signal changes. Such factors as subject motion, scanner instability and/or alterations in physiological conditions of the anesthetized animal could confound the baseline signal. The unique feature of such functional MRI (fMRI) studies necessitates a technique that is able to monitor MRI signal in a real-time fashion and to interactively control certain experimental procedures. In the present study, an approach for real-time MRI on a Bruker scanner is presented. The custom software runs on the console computer in parallel with the scanner imaging software, and no additional hardware is required. The utility of this technique is demonstrated in manganese-enhanced MRI (MEMRI) with acute cocaine challenge, in which temporary disruption of the blood-brain barrier (BBB) is a critical step for MEMRI experiments. With the aid of real-time MRI, we were able to assess the outcome of BBB disruption following bolus injection of hyperosmolar mannitol in a near real-time fashion prior to drug administration, improving experimental success rate. It is also shown that this technique can be applied to monitor baseline physiological conditions in conventional fMRI experiments using blood oxygenation level-dependent (BOLD) contrast, further demonstrating the versatility of this technique.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Lu H,Yang S,Zuo Y,Demny S,Stein EA,Yang Ydoi
10.1016/j.mri.2008.02.020subject
Has Abstractpub_date
2008-11-01 00:00:00pages
1266-72issue
9eissn
0730-725Xissn
1873-5894pii
S0730-725X(08)00079-9journal_volume
26pub_type
杂志文章abstract::Type A acute aortic dissection (TAAAD) sometimes presents with acute stroke-like symptoms. When intravenous tissue plasminogen activator (IV-tPA) therapy is considered for acute ischemic stroke, TAAAD must be excluded. Painless TAAAD presenting with acute stroke may be easily missed. Two cases of painless TAAAD presen...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.04.021
更新日期:2016-09-01 00:00:00
abstract::Several recent articles have assessed the relative efficiency of nuclear magnetic resonance (NMR) pulse sequences. One consideration that has received little attention is the effect on image contrast of displaying images without information on the sign of the reconstructed signals. The radiofrequency receivers current...
journal_title:Magnetic resonance imaging
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doi:10.1016/0730-725x(84)90193-0
更新日期:1984-01-01 00:00:00
abstract:BACKGROUND:Blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI) can provide regional measurements of oxygen content using deoxyhemoglobin paramagnetic characteristics. The apparent relaxation rate or R2*(=1/T2*) can be determined from the slope of log (intensity) versus echo time and is directly proport...
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更新日期:2012-04-01 00:00:00
abstract::Radial acquisitions can suffer from trajectory errors leading to reduced image quality. Here we present a new method of trajectory correction that uses all spokes of a radial acquisition and compare it to an existing method that uses a two-spoke pre-scan calibration. For both methods, estimates of the necessary shifts...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2014.04.006
更新日期:2014-09-01 00:00:00
abstract::Recently, we have demonstrated that the fine-digit topography (millimeter sized) previously identified in the primary somatosensory cortex (SI), using electrophysiology and intrinsic signal optical imaging, can also be mapped with submillimeter resolution using blood-oxygenation-level-dependent (BOLD) functional magne...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2007.05.002
更新日期:2007-07-01 00:00:00
abstract:PURPOSE:The state-of-the-art method to quantify sodium concentrations in vivo consists in a fully relaxed 3D spin-density (SD) weighted acquisition. Nevertheless, most sodium MRI clinical studies use short-TR SD acquisitions to reduce acquisition durations. We present a clinically viable implementation of the Variable ...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2019.01.015
更新日期:2019-05-01 00:00:00
abstract:OBJECT:Dynamic in vivo31P-NMR spectroscopy in combination with Magnetic Resonance Imaging (MRI) was used to study muscle bioenergetics of boreal and Arctic scallops (Pecten maximus and Chlamys islandica) to test the hypothesis that future Ocean Warming and Acidification (OWA) will impair the performance of marine inver...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2019.06.003
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abstract::A variety of shortcomings are associated with most currently used gastrointestinal contrast agents for magnetic resonance imaging (MRI). Artifacts resulting from peristalsis and other motions in the abdominal region are produced by many positive contrast agents (which increase signal intensity). Although this is not a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(97)00020-9
更新日期:1997-01-01 00:00:00
abstract::A case report of trismus after a dental procedure is evaluated by MR imaging. The medial and lateral pterygoid muscles showed inflammatory changes. Etiologies of trismus are reviewed. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(90)90148-u
更新日期:1990-01-01 00:00:00
abstract::Multi-contrast magnetic resonance imaging (MRI) is a useful technique to aid clinical diagnosis. This paper proposes an efficient algorithm to jointly reconstruct multiple T1/T2-weighted images of the same anatomical cross section from partially sampled k-space data. The joint reconstruction problem is formulated as m...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.08.025
更新日期:2014-12-01 00:00:00
abstract::The present study examined initial changes in non-traumatic osteonecrosis of the femoral head (ONF) on T1- and T2-weighted MR images, and fat suppression images. The subjects were 57 renal transplant recipients (37 males and 20 females), whose median age at the time of transplantation was 31.5 years old (range, 10 to ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00424-6
更新日期:2001-09-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to analyze flow patterns in the pulmonary circulation of healthy volunteers by using 4D flow magnetic resonance imaging. MATERIALS AND METHODS:The study was approved by the local ethics committee and all subjects gave written informed consent. Eighteen volunteers underwent a 4D ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.06.036
更新日期:2013-02-01 00:00:00
abstract::The objective of this study was to analyze regional variations of magnetic resonance (MR) relaxation times (T1ρ and T2) in hip joint cartilage of healthy volunteers and subjects with femoral acetabular impingement (FAI). Morphological and quantitative images of the hip joints of 12 healthy volunteers and 9 FAI patient...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2013.01.009
更新日期:2013-09-01 00:00:00
abstract:PURPOSE:To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. MATERIALS AND METHODS:DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0-T MRI was performed with a T/R head coil using the low-SAR...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.11.005
更新日期:2013-06-01 00:00:00
abstract::A simple model for estimating temperature distribution within the frozen region during cryo ablation was tested for accuracy. Freezing experiments were conducted in both ex vivo and in vivo porcine livers. Temperature was measured during freezing using a fiber-optic temperature sensor. Three-dimensional MR images were...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00389-7
更新日期:2001-06-01 00:00:00
abstract::The purpose of the study was to determine whether diffusion-weighted magnetic resonance imaging (DWI) could identify focal lesions that develop in ischemia-sensitive cerebral tissues during reperfusion following global brain ischemia. Localized 1H-Magnetic Resonance Spectroscopy (1H-MRS) measurements were also obtaine...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(96)00094-x
更新日期:1996-01-01 00:00:00
abstract::Two parallel imaging methods used for first-pass myocardial perfusion imaging were compared in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image artifacts. One used adaptive Time-adaptive SENSitivity Encoding (TSENSE) and the other used GeneRalized Autocalibrating Partially Parallel Acquisi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.10.012
更新日期:2007-06-01 00:00:00
abstract::Radio frequency magnetic fields from 5 to 100 kHz off resonance reduce longitudinal magnetization of water in some tissues without affecting the magnetization of simple solutions (Wolff, S.D.; Balaban, R.S. Magnetization transfer contrast (MTC) and tissue water proton relaxation in vivo. Magn. Reson. Med. 10:135-144; ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(90)90050-c
更新日期:1990-01-01 00:00:00
abstract::The increasing size and number of data sets of large four dimensional (three spatial, one temporal) magnetic resonance (MR) cardiac images necessitates efficient segmentation algorithms. Analysis of phase-contrast MR images yields cardiac flow information which can be manipulated to produce accurate segmentations of t...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.08.019
更新日期:2015-01-01 00:00:00
abstract::Dynamic and static gadolinium-diethylenetriaminepentaacetic acid(Gd-DTPA)-enhanced magnetic resonance imaging (MRI) were evaluated as measures of joint inflammation in arthritis, by a comparison with macroscopic and microscopic signs of synovitis. Furthermore, the importance of the size of the evaluated synovial areas...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00008-3
更新日期:1998-09-01 00:00:00
abstract::This summary attempts to provide forward-looking concepts regarding gadolinium related toxicity, as discussed in further detail in this issue. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
doi:10.1016/j.mri.2016.09.002
更新日期:2016-12-01 00:00:00
abstract::We propose a novel processing method for reducing shading artifacts in quantitative susceptibility mapping (QSM) for prostate imaging. In the conventional method, calculation errors in the boundary regions between water and fat cause shading artifacts that degrade the image quality for QSM. In the proposed method, wat...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.11.006
更新日期:2020-02-01 00:00:00
abstract::White matter loss, ventricular enlargement and white matter lesions are common findings on brain scans of older subjects. Accurate assessment of these different features is therefore essential for normal aging research. Recently, we developed a novel unsupervised classification method, named 'Multispectral Coloring Mo...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2011.09.016
更新日期:2012-02-01 00:00:00
abstract::We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate the translational and rotational mobility of adsorbents on quartz and calcite mineral surfaces. On both surfaces it was found that water is the dominant molecule. On the quartz surface the majority of water molecules have a ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.10.002
更新日期:2019-02-01 00:00:00
abstract::Macroscopic protonation constants were measured for a series of DTPA mono- and bis-amide ligands using potentiometric titrations. Proton NMR pH titrations yielded protonation populations of the various nitrogen and oxygen basic sites of the ligands for the different protonation stages. Amide formation decreased the ba...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)00117-l
更新日期:1995-01-01 00:00:00
abstract::We have synthesized a surface functionalized superparamagnetic iron oxide colloid whose clearance from the vascular compartment was inhibited by asialofetuin but not fetuin. Unlike other particulate or colloidal magnetic resonance (MR) contrast agents, the agent of the current communication is not withdrawn from the v...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(90)90143-p
更新日期:1990-01-01 00:00:00
abstract::Relaxation times estimation methods play a central role in various problems, such as magnetic resonance (MR) hardware calibration, tissue characterization, or temperature measurement. Previous studies have proposed optimization criteria to estimate the relaxation time T1 faster than with a multipoint method leading to...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(99)00092-2
更新日期:1999-11-01 00:00:00
abstract::The objective of this study was to describe magnetic resonance (MR) findings with a 1.5T imager for hepatic parenchymal changes after proton beam radiotherapy. Thirty-two patients who received proton radiotherapy with doses of 50-87 Gy underwent MR imaging 1-75 months (mean 22 months) after the start of irradiation. A...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00152-1
更新日期:2000-07-01 00:00:00
abstract::Zero-mean noise introduced into quadrature detected MRI signals is generally rectified by the reconstruction algorithm to give a nonzero background intensity in the displayed image. In low signal-to-noise ratio (SNR) images, this background will inflate region of interest (ROI) signal measurements, leading to improper...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(93)90225-3
更新日期:1993-01-01 00:00:00
abstract::The apparent diffusion coefficient (ADC) measured using magnetic resonance imaging methods provides information on microstructural properties of biological tissues, and thus has found applications as a useful biomarker for assessing changes such as those that occur in ischemic stroke and cancer. Conventional pulsed gr...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2010.10.002
更新日期:2011-04-01 00:00:00