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Result : Searchterm 'Susceptibility' found in 3 terms [] and 43 definitions []
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Searchterm 'Susceptibility' was also found in the following services: 
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News  (3)  Resources  (1)  Forum  (6)  
 
Moire Fringes (Artifact)InfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Quick Overview
Artifact Information
NAME
Moire fringes, moire
DESCRIPTION
Superimposed signals of different phases
REASON
Interferences
HELP
Surface coil, shimming
A moiré pattern is an interference pattern created for example when two grids are overlaid at an angle, or when they have slightly different mesh sizes. The human visual system creates an imaginary pattern of roughly horizontal dark and light bands, the moiré pattern that appears to be superimposed on the lines.
In MRI, the appearance of moiré fringes can be caused by a variety of reasons e.g., inhomogeneity of the main magnetic field caused by a defect shielding (interference with RF pulses), interferences produced by aliasing, and interferences of echoes from different excitation modes (with different echo times).
mri safety guidance
Image Guidance
Take spin echo-based techniques, or a surface coil. This artifact is often sensitive to shimming or susceptibility gradients.
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Further Reading:
  Basics:
MRI Artifact Gallery
   by chickscope.beckman.uiuc.edu    
Moiré pattern
   by en.wikipedia.org    
Moire Fringes
   by www.mritutor.org    
MRI Resources 
Claustrophobia - Anatomy - Universities - Developers - Sequences - Mass Spectrometry
 
Oral Contrast AgentsForum -
related threadsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
A limitation of abdominal MRI can be the assessment of malignancies by difficulties to distinguish bowel from other organs or malignant masses. The use of oral contrast agents can reduce this problem. Properties of an ideal oral contrast agent are little or no absorption by the stomach or intestines, complete excretion, no motion or susceptibility artifacts, and uniform marking of the GI tract.
Gastrointestinal MRI contrast agents are divided in materials with bright appearance or dark appearance. The choice of a negative or a positive oral contrast agent depends on the specific problem or the pulse sequence.

See also Positive Oral Contrast Agents, Negative Oral Contrast Agents, Gastrointestinal Diamagnetic Contrast Agents, Gastrointestinal Paramagnetic Contrast Agents and Gastrointestinal Superparamagnetic Contrast Agents.

See also the related poll result: 'The development of contrast agents in MRI is'
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• View the DATABASE results for 'Oral Contrast Agents' (17).Open this link in a new window

 
Further Reading:
  News & More:
Usefulness of MR Imaging for Diseases of the Small Intestine: Comparison with CT
2000   by www.ncbi.nlm.nih.gov    
Nottingham scientists exploit MRI technology to assist in the treatment of IBS
Thursday, 9 January 2014   by www.news-medical.net    
MRI Resources 
Calculation - Equipment - Collections - Mobile MRI - Fluorescence - Distributors
 
PRinciples of Echo Shifting using a Train of ObservationsInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(PRESTO) PRESTO is a 3 dimensional ultrafast gradient echo sequence that combines the whole brain coverage with T2* weighted imaging. PRESTO is useful for BOLD and perfusion imaging studies. In combination with parallel imaging techniques, PRESTO provides higher temporal resolution and more coverage compared to traditional multi slice imaging. In addition, the sensitivity to susceptibility artifacts and flow phenomena is reduced, compared with EPI techniques, enabling MRI scans throughout the brain including the skull base.

See also T2 Star.
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• View the DATABASE results for 'PRinciples of Echo Shifting using a Train of Observations' (2).Open this link in a new window

 
Further Reading:
  News & More:
Chest MRI Using Multivane-XD, a Novel T2-Weighted Free Breathing MR Sequence
Thursday, 11 July 2019   by www.sciencedirect.co    
T2-Weighted Liver MRI Using the MultiVane Technique at 3T: Comparison with Conventional T2-Weighted MRI
Friday, 16 October 2015   by www.ncbi.nlm.nih.gov    
Searchterm 'Susceptibility' was also found in the following services: 
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News  (3)  Resources  (1)  Forum  (6)  
 
Paramagnetic SubstanceInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
Substances exhibiting paramagnetic properties are used as contrast agents in MR imaging. They have a small but positive magnetic susceptibility (magnetizability - tends to align along the magnetic field). Typical paramagnetic substances usually possess an unpaired electron and include atoms or ions of transition elements, rare earth elements, some metals, and some molecules including molecular oxygen and free radicals.

See also Paramagnetism.
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• View the DATABASE results for 'Paramagnetic Substance' (8).Open this link in a new window

 
Further Reading:
  Basics:
IMAGE CONTRAST IN MRI(.pdf)
   by www.assaftal.com    
LEARNING CENTER FOR PARAMAGNETISM
2003   by www.naturesalternatives.com    
MRI Resources 
Portals - Education pool - Colonography - Stent - Implant and Prosthesis - Patient Information
 
Paramagnetism
 
Paramagnetic materials attract and repel like normal magnets when subject to a magnetic field. This alignment of the atomic dipoles with the magnetic field tends to strengthen it, and is described by a relative magnetic permeability greater than unity. Paramagnetism requires that the atoms individually have permanent dipole moments even without an applied field, which typically implies a partially filled electron shell. In pure Paramagnetism (without an external magnetic field), these atomic dipoles do not interact with one another and are randomly oriented in the absence of an external field, resulting in zero net moment.
Paramagnetic materials in magnetic fields will act like magnets but when the field is removed, thermal motion will quickly disrupt the magnetic alignment. In general, paramagnetic effects are small (magnetic susceptibility of the order of 10-3 to 10-5).
In MRI, gadolinium (Gd) one of these paramagnetic materials is used as a contrast agent. Through interactions between the electron spins of the paramagnetic gadolinium and the water nuclei nearby, the relaxation rates (T1 and T2) of the water protons are increased (T1 and T2 times are decreased), causing an increase in signal on T1 weighted images.

See also contrast agents, magnetism, ferromagnetism, superparamagnetism, and diamagnetism.
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• View the DATABASE results for 'Paramagnetism' (11).Open this link in a new window

 
Further Reading:
  Basics:
Magnet basics
   by my.execpc.com    
Paramagnetism
Wednesday, 23 November 2005   by en.wikipedia.org    
  News & More:
LEARNING CENTER FOR PARAMAGNETISM
2003   by www.naturesalternatives.com    
MRI Resources 
MRI Technician and Technologist Career - RIS - Cardiovascular Imaging - Artifacts - Cochlear Implant - Anatomy
 
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