Name: using 23na magnetic resonance imaging to measure sodium in muscle tissues
Uploaded: 2024-02-29T13:13:38.000+00:00
Duration: 1 min 11 s
Description: All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human ...

sodium magnetic resonance imaging to measure tissue sodium content

Sodium Magnetic Resonance Imaging to Measure Tissue Sodium Content

Begin by embedding calibration standard sodium chloride solutions in the MRI phantom holder of the coil.
Position the participant on the MRI table in a supine position.
For imaging of the calf at the mid-gastrocnemius muscle, place the phantom holder inside the radiofrequency coil. Position the left lower leg over the phantom holder. Secure the top half of the radiofrequency coil in place.
For sodium imaging, use the three-dimensional gradient-echo sequence as described in the text protocol.
Further, acquire fat- and water-weighted images of the tissue using the mDixon protocol keeping the scanning parameters consistent. Complete the multinuclear exam of the lower extremity.
After the completion of the scan, calibrate the measured sodium signal intensities to the standard sodium chloride concentrations on a per-voxel basis.
Prepare a quantitative sodium map of the tissue and interpolate it to match the matrix size of the fat- and water-weighted mDixon images.
Select each region of interest on the water-weighted mDixon image. Further, segment the outer and inner borders of the skin, total muscle, bone, blood vessels, and subcutaneous adipose tissue. Segment the skin region further into the posterior semi-perimeter of the skin.
Remove the voxels from the bone and blood vessels from the analyses.
Obtain accurate muscle tissue sodium quantification.

sodium-magnetic-resonance-imaging-to-measure-tissue-sodium-content

Without Section

Research

JoVE Encyclopedia of Experiments

Immunology

Immunodiagnostics

Imaging and Visualization Techniques

Using 23Na Magnetic Resonance Imaging to Measure Sodium in Muscle Tissues

EoE Sub Articles

eoe sub articles

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.
1. Preparation of the phantom holder
<ol>
	<li>Four standard sodium solutions, including aqueous NaCl in the physiologic range of peripheral tissue sodium content 10-40 mmol/L, are embedded in a platform in the coil.</li>
</ol>
2. MRI examination
The quantification of Na+ content at the mid-calf area is measured using an MRI exam on a 3.0 T MR scanner (Philips Healthcare, Cleveland, OH, USA) and a single-tuned receive-only quadrature sodium coil (Rapid Biomedical GmbH, Rimpar, Germany).
<ol>
	<li>Place the participant in a supine position on the MRI patient table.</li>
	<li>For imaging of the calf at the mid gastrocnemius muscle, place the phantom holder inside the RF coil and rest the left lower leg on top of the phantom holder before closing the top half of the RF coil.</li>
	<li>Use the three-dimensional gradient-echo sequence as follows.</li>
	<li>Field of view = 192 &#215; 192 mm2, acquired matrix size = 64 &#215; 64, and slice thickness = 30 mm. A repetition time (TR) and echo time (TE) of 130/0.99 milliseconds is preferred to reduce error from residual T1 signal effects.</li>
	<li>Acquire fat and water images using the mDixon protocol, with matching field of view (FOV) and matrix size to the three-dimensional gradient-echo sequence.</li>
	<li>The sodium image acquisition time is approximately 15 minutes.</li>
	<li>The total multinuclear MRI exam of the lower extremity is approximately 30 minutes.</li>
</ol>
3. Image Analysis
<ol>
	<li>Measure the mean signal intensity in the standard sodium solutions.</li>
	<li>Calibrate the magnitude of sodium signal intensity to the standard sodium concentrations on a per-voxel basis.</li>
	<li>Make a quantitative sodium map and match the matrix size of the fat/water mDixon images.</li>
	<li>Segment each region of interest using the water image from mDixon, including the outer and inner borders of the skin, total muscle, bone, blood vessels, and sub-adipose tissue (SAT).</li>
	<li>Segment the skin region further into the posterior semiperimeter of the skin.</li>
	<li>Remove the voxels in the bone and blood vessels.</li>
	<li>Quantified metrics include Skin sodium (mM/L), SAT sodium (mM/L), Muscle sodium (mM/L), Circumference (cm), SAT volume (mm2), Muscle volume (mm2), Fat/Water ratio, and Fat Signal Fraction.</li>
</ol>

using 23na magnetic resonance imaging to measure sodium in muscle tissues

This video demonstrates the quantification of sodium content in human tissues using sodium magnetic resonance imaging (23Na-MRI). The patient&#39;s lower leg is placed within the radiofrequency (RF) coil of the machine, and a three-dimensional gradient-echo sequence is performed. Multinuclear MRI images are generated using hydrogen and sodium nuclei to quantify sodium levels in various tissues.

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human ...

Place the patient&#39;s lower leg within the radiofrequency coil of the magnetic resonance imaging or MRI machine.
The coil contains various sodium concentrations as standards to measure tissue sodium accumulation.
Initiate a sodium-MRI scan.
The coil detects fluctuations in the MR signal intensity emitted from the tissue, influenced by the distribution and concentration of sodium ions. 
Obtain a total tissue sodium map displaying areas with varying color intensities corresponding to the sodium levels. 
Compare these intensities with standard sodium concentrations, which aid in measuring total tissue sodium levels. 
 Bright colors indicate higher levels, while darker colors indicate lower levels. 
 Next, capture signals corresponding to the fat and water content of the tissue to generate images of the non-muscle regions.
 Subtract non-muscle regions from the total tissue sodium map to generate a refined image and measure muscle tissue sodium content.

using-23na-magnetic-resonance-imaging-to-measure-sodium-muscle

256 vues. Imagerie par résonance magnétique sodique pour mesurer la teneur en sodium des tissus

Vidéo: Imagerie par résonance magnétique sodique pour mesurer la teneur en sodium des tissus - Expérience

Automated Segmentation of Cortical Grey Matter from T1-Weighted MRI Images

Within neuroimaging research, a number of recent studies have discussed the impact of between-study differences in volumetric findings that are thought to result from the use of different segmentation tools to generate brain volumes. Here, processing pipelines for seven automated tools that can be used to segment grey matter within the brain are presented. The protocol provides an initial step for researchers aiming to find the most accurate method for generating grey matter volumes from T1-weighted MRI scans. Steps to undertake detailed visual quality control are also included in the manuscript. This protocol covers a range of potential segmentation tools and encourages users to compare the performance of these tools within a subset of their data before selecting one to apply to a full cohort. Furthermore, the protocol may be further generalized to the segmentation of other brain regions.

This protocol describes the process of applying seven different automated segmentation tools to structural T1-weighted MRI scans to delineate grey matter regions that can be used for the quantification of grey matter volume.

Segmentation automatique de substance grise corticale des Images d’IRM pondérées en T1

Within neuroimaging research, a number of recent studies have discussed the impact of between-study differences in volumetric findings that are thought to ...

Recherche

JoVE Journal

Neurosciences

Functional MRI in Conjunction with a Novel MRI-compatible Hand-induced Robotic Device to Evaluate Rehabilitation of Individuals Recovering from Hand Grip Deficits

Functional magnetic resonance imaging (fMRI) is a non-invasive magnetic resonance imaging technique that images brain activation in vivo, using endogenous deoxyhemoglobin as an endogenous contrast agent to detect changes in blood-level-dependent oxygenation (BOLD effect). We combined fMRI with a novel robotic device (MR-compatible hand-induced robotic device [MR_CHIROD]) so that a person in the scanner can execute a controlled motor task, hand-squeezing, which is a very important hand movement to study in neurological motor disease. We employed parallel imaging (generalized auto-calibrating partially parallel acquisitions [GRAPPA]), which allowed higher spatial resolution resulting in increased sensitivity to BOLD. The combination of fMRI with the hand-induced robotic device allowed precise control and monitoring of the task that was executed while a participant was in the scanner; this may prove to be of utility in rehabilitation of hand motor function in patients recovering from neurological deficits (e.g., stroke). Here we outline the protocol for using the current prototype of the MR_CHIROD during an fMRI scan.

We performed functional MRI using a novel MRI-compatible hand-induced robotic device to evaluate its utility for monitoring hand motor function in individuals recovering from neurological deficits.

IRM fonctionnelle en conjonction avec un nouveau dispositif robotique induit par l'IRM pour évaluer la réadaptation des personnes qui se remettent d'un déficit de poignée de main

Functional magnetic resonance imaging (fMRI) is a non-invasive magnetic resonance imaging technique that images brain activation in vivo, using endogenous ...

Concurrent EEG and Functional MRI Recording and Integration Analysis for Dynamic Cortical Activity Imaging

Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are two of the fundamental noninvasive methods for identifying brain activity. Multimodal methods have sought to combine the high temporal resolution of EEG with the spatial precision of fMRI, but the complexity of this approach is currently in need of improvement. The protocol presented here describes the recently developed spatiotemporal fMRI-constrained EEG source imaging method, which seeks to rectify source biases and improve EEG-fMRI source localization through the dynamic recruitment of fMRI sub-regions. The process begins with the collection of multimodal data from concurrent EEG and fMRI scans, the generation of 3D cortical models, and independent EEG and fMRI processing. The processed fMRI activation maps are then split into multiple priors, according to their location and surrounding area. These are taken as priors in a two-level hierarchical Bayesian algorithm for EEG source localization. For each window of interest (defined by the operator), specific segments of the fMRI activation map will be identified as active to optimize a parameter known as model evidence. These will be used as soft constraints on the identified cortical activity, increasing the specificity of the multimodal imaging method by reducing cross-talk and avoiding erroneous activity in other conditionally active fMRI regions. The method generates cortical maps of activity and time-courses, which may be taken as final results, or used as a basis for further analyses (analyses of correlation, causation, etc.) While the method is somewhat limited by its modalities (it will not find EEG-invisible sources), it is broadly compatible with most major processing software, and is suitable for most neuroimaging studies.

An EEG-fMRI multimodal imaging method, known as the spatiotemporal fMRI-constrained EEG source imaging method, is described here. The presented method employs conditionally-active fMRI sub-maps, or priors, to guide EEG source localization in a manner that improves spatial specificity and limits erroneous results.

Using ²³Na Magnetic Resonance Imaging to Measure Sodium in Muscle Tissues

Transcription