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 'Chemical Shift Artifact' 
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Result : Searchterm 'Chemical Shift Artifact' found in 1 term [] and 7 definitions [], (+ 4 Boolean[] results
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Dual Echo Fast Gradient EchoInfoSheet: - Sequences - 
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(DE FGRE, Dual/FFE, DE FFE) Simultaneously acquired in and out of phase TE gradient echo images. To quantitatively measure the signal intensity differences between out of phase and in phase images the parameters should be the same except for the TE.
The chemical shift artifact appearing on the out-of-phase image allows for the detection of lipids in the liver or adrenal gland, such as diffuse fatty infiltration, focal fatty infiltration, focal fatty sparing, benign adrenocortical masses and intracellular lipids within a hepatocellar neoplasm, where spin echo and fat suppression techniques are not as sensitive. Specific pathologies that have been reported include liver lipoma, angiomyolipoma, myelolipoma, metastatic liposarcoma, teratocarcinoma, melanoma, haemorrhagic neoplasm and metastatic choriocarcinoma.
 
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Adrenal Myelolipoma
Tuesday, 19 June 2001   by www.emedicine.com    
MRI Resources 
Spine MRI - Colonography - Jobs pool - Crystallography - Movies - Supplies
 
Field StrengthForum -
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In every MR examination, a large static magnetic field is applied. Field strengths for clinical equipment can vary between 0.2 and 3 T; experimental imaging units have a field strength of up to 11 T, depending on the MRI equipment used. In MRS, field strengths up to 12 T are currently used. The field strength of the magnet will influence the quality of the MR image regarding chemical shift artifacts, the signal to noise ratio (SNR), motion sensitivity and susceptibility artifacts.

See also the related poll result: 'In 2010 your scanner will probably work with a field strength of'
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• View the DATABASE results for 'Field Strength' (123).Open this link in a new window


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Further Reading:
  Basics:
What affects the strength of a magnet?
   by my.execpc.com    
Magnetic Field of the Strongest Magnet
2003   by hypertextbook.com    
  News & More:
Impact of Magnetic Field Inhomogeneity on the Quality of Magnetic Resonance Images and Compensation Techniques: A Review
Saturday, 1 October 2022   by www.dovepress.com    
Low Power MRI Helps Image Lungs, Brings Costs Down
Thursday, 10 October 2019   by www.medgadget.com    
Opportunities in Interventional and Diagnostic Imaging by Using High-performance Low-Field-Strength MRI
Tuesday, 1 October 2019   by pubs.rsna.org    
Low-field MRI: An MR physics perspective
Sunday, 13 January 2019   by onlinelibrary.wiley.com    
Ultra-high-field MRI allows for earlier diagnosis of multiple sclerosis
Friday, 4 May 2007   by www.eurekalert.org    
Low-intensity MRI takes first scan of a human brain
Wednesday, 14 November 2007   by technology.newscientist.com    
MRI Resources 
General - Health - Spectroscopy pool - MRCP - MRI Technician and Technologist Career - Knee MRI
 
Spatial Misregistration ArtifactInfoSheet: - Artifacts - 
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An effect of chemical shift is that of spatial misregistration. Because the frequency displacement caused by chemical shift cannot be differentiated from intended spatial frequency encoding misregistration of the resultant signal may occur along the frequency-encoding direction. This artifact can be seen in a FFE or SE sequence as a bright or dark band at the edge of the anatomy.

See Chemical Shift Artifact.
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ArtifactForum -
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An image artifact is a structure not normally present but visible as a result of a limitation or malfunction in the hardware or software of the MRI device, or in other cases a consequence of environmental influences as heat or humidity or it can be caused by the human body (blood flow, implants etc.). The knowledge of MRI artifacts (brit. artefacts) and noise producing factors is important for continuing maintenance of high image quality. Artifacts may be very noticeable or just a few pixels out of balance but can give confusing artifactual appearances with pathology that may be misdiagnosed.
Changes in patient position, different pulse sequences, metallic artifacts, or other imaging variables can cause image distortions, which can be reduced by the operator; artifacts due to the MR system may require a service engineer.
Many types of artifacts may occur in magnetic resonance imaging. Artifacts in magnetic resonance imaging are typically classified as to their basic principles, e.g.:
•
Physiologic (motion, flow)
•
Hardware (electromagnetic spikes, ringing)
•
Inherent physics (chemical shift, susceptibility, metal)

Several techniques are developed to reduce these artifacts (e.g. respiratory compensation, cardiac gating, eddy current compensation) but sometimes these effects can also be exploited, e.g. for flow measurements.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'
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• View the DATABASE results for 'Artifact' (166).Open this link in a new window

 
Further Reading:
  Basics:
ARTEFACT VERSUS ARTIFACT
Saturday, 26 January 2002   by www.worldwidewords.org    
  News & More:
MRI results affected by movement? MIT researchers have an AI-powered solution
Friday, 25 August 2023   by healthimaging.com    
Magnetic eyelashes: A new source of MRI artifacts
Wednesday, 24 July 2019   by medicalxpress.com    
On the Horizon - Next Generation MRI
Wednesday, 23 October 2013   by thefutureofthings.com    
MRI Resources 
Raman Spectroscopy - Cardiovascular Imaging - Used and Refurbished MRI Equipment - Spectroscopy - MRI Centers - Stimulator pool
 
Spin EchoForum -
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(SE) The Reappearance of the MR signal after the FID has apparently died away, as a result of the effective reversal (rephasing) of the dephasing spins by techniques such as specific RF pulse sequences or pairs of field gradient pulses, applied in time shorter than or on the order of T2. Proper selection of the TE time of the pulse sequence can help to control the amount of T1 or T2 contrast present in the image. Pulse sequences of the spin echo type, usually employs a 90° pulse, followed by one or more 180° pulses to eliminate field inhomogeneity and chemical shift effects at the echo. Caused by this 180° refocusing pulse, spin echo or fast spin echo (FSE, TSE) sequences are more robust against e.g. susceptibility artifacts than sequences of the gradient echo type.
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Further Reading:
  Basics:
Spin echoes, CPMG and T2 relaxation - Introductory NMR & MRI from Magritek
2013   by www.azom.com    
  News & More:
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
MRI Resources 
Artifacts - Health - Lung Imaging - Hospitals - Guidance - Intraoperative MRI
 
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