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Result : Searchterm 'Magnetic Resonance' found in 21 terms [] and 109 definitions []
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Searchterm 'Magnetic Resonance' was also found in the following services: 
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News  (787)  Resources  (181)  Forum  (1)  
 
Diffusion Weighted ImagingForum -
related threadsMRI Resource Directory:
 - Diffusion Weighted Imaging -
 
(DWI) Magnetic resonance imaging is sensitive to diffusion, because the diffusion of water molecules along a field gradient reduces the MR signal. In areas of lower diffusion the signal loss is less intense and the display from this areas is brighter. The use of a bipolar gradient pulse and suitable pulse sequences permits the acquisition of diffusion weighted images (images in which areas of rapid proton diffusion can be distinguished from areas with slow diffusion).
Based on echo planar imaging, multislice DWI is today a standard for imaging brain infarction. With enhanced gradients, the whole brain can be scanned within seconds. The degree of diffusion weighting correlates with the strength of the diffusion gradients, characterized by the b-value, which is a function of the gradient related parameters: strength, duration, and the period between diffusion gradients.
Certain illnesses show restrictions of diffusion, for example demyelinization and cytotoxic edema. Areas of cerebral infarction have decreased apparent diffusion, which results in increased signal intensity on diffusion weighted MRI scans. DWI has been demonstrated to be more sensitive for the early detection of stroke than standard pulse sequences and is closely related to temperature mapping.
DWIBS is a new diffusion weighted imaging technique for the whole body that produces PET-like images. The DWIBS sequence has been developed with the aim to detect lymph nodes and to differentiate normal and hyperplastic from metastatic lymph nodes. This may be possible caused by alterations in microcirculation and water diffusivity within cancer metastases in lymph nodes.

See also Diffusion Weighted Sequence, Perfusion Imaging, ADC Map, Apparent Diffusion Coefficient, and Diffusion Tensor Imaging.
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• Related Searches:
    • Molecule
    • Diffusion Tensor Tractography
    • B-Value
    • Eigenvalues
    • Intravoxel Incoherent Motion
 
Further Reading:
  Basics:
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
Novel MRI Technique Could Reduce Breast Biopsies, University of Washington Study
Tuesday, 2 October 2012   by www.eurekalert.org    
Quantitative Apparent Diffusion Coefficient Measurements Obtained by 3-Tesla MRI Are Correlated with Biomarkers of Bladder Cancer Proliferative Activity
   by www.plosone.org    
  News & More:
Stability and repeatability of diffusion-weighted imaging (DWI) of normal pancreas on 5.0 Tesla magnetic resonance imaging (MRI)
Monday, 24 July 2023   by www.nature.com    
MRI innovation makes cancerous tissue light up and easier to see
Monday, 21 March 2022   by www.sciencedaily.com    
Diffusion MRI and machine learning models classify childhood brain tumours
Saturday, 6 March 2021   by physicsworld.com    
Diffusion-weighted MRI in Advanced Epithelial Ovarian Cancer: Apparent Diffusion Coefficient as a Response Marker
Tuesday, 1 October 2019   by pubs.rsna.org    
Novel Imaging Technique Improves Prostate Cancer Detection
Tuesday, 6 January 2015   by health.ucsd.edu    
High-b-value Diffusion-weighted MR Imaging of Suspected Brain Infarction
2000   by www.ajnr.org    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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DixonInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
The Dixon technique is a MRI method used for fat suppression and/or fat quantification. The difference in magnetic resonance frequencies between fat and water-bound protons allows the separation of water and fat images based on the chemical shift effect.
This imaging technique is named after Dixon, who published in 1984 the basic idea to use phase differences to calculate water and fat components in postprocessing. Dixon's method relies on acquiring an image when fat and water are 'in phase', and another in 'opposed phase' (out of phase). These images are then added together to get water-only images, and subtracted to get fat-only images. Therefore, this sequence type can deliver up to 4 contrasts in one measurement: in phase, opposed phase, water and fat images. An additional benefit of Dixon imaging is that source images and fat images are also available to the diagnosing physician.
The original two point Dixon sequence (number of points means the number of images acquired at different TE) had limited possibilities to optimize the echo time, spatial resolution, slice thickness, and scan time; but Dixon based fat suppression can be very effective in areas of high magnetic susceptibility, where other techniques fail. This insensitivity to magnetic field inhomogeneity and the possibility of direct image-based water and fat quantification have currently generated high research interests and improvements to the basic method (three point Dixon).
The combination of Dixon with gradient echo sequences allows for example liver imaging with 4 image types in one breath hold. With Dixon TSE/FSE an excellent fat suppression with high resolution can be achieved, particularly useful in imaging of the extremities.
For low bandwidth imaging, chemical shift correction of fat images can be made before recombination with water images to produce images free of chemical shift displacement artifacts. The need to acquire more echoes lengthens the minimum scan time, but the lack of fat saturation pulses extends the maximum slice coverage resulting in comparable scan time.
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Further Reading:
  Basics:
Separation of fat and water signal in magnetic resonanace imaging
2011   by www.diva-portal.org    
Direct Water and Fat Determination in Two-Point Dixon Imaging
April 2013   by scholarship.rice.edu    
MRI evaluation of fatty liver in day to day practice: Quantitative and qualitative methods
Wednesday, 3 September 2014   by www.sciencedirect.com    
Measurement of Fat/Water Ratios in Rat Liver Using 3DThree-Point Dixon MRI
2004   by www.civm.duhs.duke.edu    
  News & More:
The utility of texture analysis of kidney MRI for evaluating renal dysfunction with multiclass classification model
Tuesday, 30 August 2022   by www.nature.com    
Liver Imaging Today
Friday, 1 February 2013   by www.healthcare.siemens.it    
mDIXON being developed to simplify and accelerate liver MRI
September 2010   by incenter.medical.philips.com    
MRI Resources 
Breast MRI - Nerve Stimulator - Jobs - Databases - Spectroscopy pool - Cochlear Implant
 
Dotarem®InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
Dotarem® is a paramagnetic ionic MRI contrast agent. Extracellular contrast agents like Dotarem®, can be bolus injected because of the relatively low rate of side effects. This contrast medium is useable to enhance signal intensity in magnetic resonance imaging for intracranial and spinal lesions with an abnormal blood brain barrier or abnormal vascularity, and in whole body imaging.

WARNING: NEPHROGENIC SYSTEMIC FIBROSIS Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with acute or chronic severe renal insufficiency (glomerular filtration rate less than 30 mL/min/1.73m2), or acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.
Drug Information and Specification
NAME OF COMPOUND
DEVELOPER
CENTRAL MOIETY
Gd2+
CONTRAST EFFECT
T1, Predominantly positive enhancement
r1=3.4, r2=4.8, B0=1.0T
PHARMACOKINETIC
Intravascular, extracellular, renal excretion
1350 mosm/kgH2O
CONCENTRATION
0.5 mol/L
DOSAGE
0.1 mmol/kg / 0.2mL/kg
PREPARATION
Finished product
INDICATION
Neuro/whole body
DEVELOPMENT STAGE
For sale
DISTRIBUTOR
See below
PRESENTATION
Vials of 5, 10, 15, 20mL
Pre-filled syringes of 15 and 20 mL
DO NOT RELY ON THE INFORMATION PROVIDED HERE, THEY ARE
NOT A SUBSTITUTE FOR THE ACCOMPANYING PACKAGE INSERT!
Distribution Information
TERRITORY
TRADE NAME
DEVELOPMENT
STAGE
DISTRIBUTOR
France, Switzerland
Artirem®
for sale
Australia
for sale
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Further Reading:
  Basics:
Important Drug Warning for Gadolinium-Based Contrast Agents
Wednesday, 12 September 2007   by www.ismrm.org    
  News & More:
RSNA Statement on Gadolinium-Based MR Contrast Agents
Thursday, 1 February 2018   by www.rsna.org    
EMA's final opinion confirms restrictions on use of linear gadolinium agents in body scans
Friday, 21 July 2017   by www.ema.europa.eu    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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EchoForum -
related threads
 
In MRI, an echo is the emission of energy in form of an electromagnetic resonance signal of a nuclei after its excitation. At this point spins are back in phase again and the signal is measured. The desired number of echoes is selectable. Often until eight echoes are permissible for 2D or 3D scans using spin echo, inversion recovery or MIX techniques. Two echoes are permissible for all other techniques. A multi echo imaging sequence is needed for simultaneous measurement of T2 and density weighted images.
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Further Reading:
  News & More:
Ultrashort echo time (UTE) MRI of the spine in thalassaemia
February 2004   by bjr.birjournals.org    
UCLA chemists use MRI to peek at temperatures of gases inside catalytic reactors
Thursday, 24 October 2013   by esciencenews.com    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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Radiology  (14) Open this link in a new windowUltrasound  (27) Open this link in a new window
Electron Spin Resonance
 
(ESR) Electron spin resonance is a spectroscopic technique to identify paramagnetic substances. This magnetic resonance phenomenon investigates the nature of the bonding within molecules by identifying unpaired electrons, e.g. in free radicals and their interaction with their immediate surroundings. The Larmor frequency are much higher than corresponding NMR frequencies in the same static magnetic field.
Nuclei with an odd number of neutrons and/or protons, because of their spin, react like tiny magnets and can be lined up in an applied magnetic field. Energy applied by alternating radio frequency radiation is absorbed when its frequency coincides with that of precession of the electron magnets. The spectrum of radiation absorbed as the field changes gives information valuable in chemistry, biology, and medicine since over 50 years.
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Further Reading:
  Basics:
Electron Spin Resonance
   by hyperphysics.phy-astr.gsu.edu    
  News & More:
After merging resources, chemist, retina surgeon see melanin's value in new light
Thursday, 18 August 2005   by chronicle.uchicago.edu    
MRI Resources 
Functional MRI - Pediatric and Fetal MRI - Breast MRI - Hospitals - Service and Support - Crystallography
 
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