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Result : Searchterm 'Inversion' found in 17 terms [] and 43 definitions []
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Searchterm 'Inversion' was also found in the following services: 
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News  (1)  Resources  (2)  Forum  (13)  
 
Echo TimeForum -
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(TE) The echo time represents the time in milliseconds between the application of the 90° pulse and the peak of the echo signal in spin echo and inversion recovery pulse sequences.

See also Repetition Time, Spin Echo Sequence and Inversion Recovery Sequence.
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    • Gradient Echo
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    • Repetition Time
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Further Reading:
  Basics:
Magnetic resonance imaging
   by www.scholarpedia.org    
  News & More:
Kidney stone imaging with 3D ultra-short echo time (UTE) magnetic resonance imaging. A phantom study - Abstract
Wednesday, 11 March 2015   by www.urotoday.com    
Ultrashort echo time (UTE) MRI of the spine in thalassaemia
February 2004   by bjr.birjournals.org    
Searchterm 'Inversion' was also found in the following services: 
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Radiology  (1) Open this link in a new windowUltrasound  (15) Open this link in a new window
Fat SuppressionForum -
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Fat suppression is the process of utilizing specific MRI parameters to remove the deleterious effects of fat from the resulting images , e.g. with STIR, FAT SAT sequences, water selective (PROSET WATS - water only selection, also FATS - fat only selection possible) excitation techniques, or pulse sequences based on the Dixon method.
Spin magnetization can be modulated by using special RF pulses. CHESS or its variations like SPIR, SPAIR (Spectral Selection Attenuated Inversion Recovery) and FAT SAT use frequency selective excitation pulses, which produce fat saturation.
Fat suppression techniques are nearly used in all body parts and belong to every standard MRI protocol of joints like knee, shoulder, hips, etc.
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Imaging of, e.g. the foot can induce bad fat suppression with SPIR/FAT SAT due to the asymmetric volume of this body part. The volume of the foot alters the magnetic field to a different degree than the smaller volume of the lower leg affecting the protons there. There is only a small band of tissue where the fat protons are precessing at the frequency expected, resulting in frequency selective fat saturation working only in that area. This can be corrected by volume shimming or creating a more symmetrical volume being imaged with water bags.
Even with their longer scan time and motion sensitivity, STIR (short T1/tau inversion recovery) sequences are often the better choice to suppress fat. STIR images are also preferred because of the decreased sensitivity to field inhomogeneities, permitting larger fields of views when compared to fat suppressed images and the ability to image away from the isocenter.
See also Knee MRI.
Sequences based on Dixon turbo spin echo (fast spin echo) can deliver a significant better fat suppression than conventional TSE/FSE imaging.
 
Images, Movies, Sliders:
 Shoulder Axial T2 FatSat FRFSE  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 MRI Orbita T2 FatSat  Open this link in a new window
    
 Knee MRI Sagittal STIR 001  Open this link in a new window
 MRI - Anatomic Imaging of the Ankle 3  Open this link in a new window
    
SlidersSliders Overview

 
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• View the DATABASE results for 'Fat Suppression' (28).Open this link in a new window

 
Further Reading:
  Basics:
Techniques of Fat Suppression(.pdf)
   by cds.ismrm.org    
  News & More:
Enhanced Fast GRadient Echo 3-Dimensional (efgre3D) or THRIVE
   by www.mri.tju.edu    
Ultrashort echo time (UTE) MRI of the spine in thalassaemia
February 2004   by bjr.birjournals.org    
MRI Resources 
MRI Physics - Image Quality - Stimulator pool - Pregnancy - Contrast Agents - Veterinary MRI
 
Interpulse Times
 
(T) Times between successive RF pulses used in pulse sequences. Particularly important are the inversion time (TI) in inversion recovery, and the time between 90° pulse and the subsequent 180° pulse to produce a spin echo, which will be approximately one half the spin echo time(TE). The time between repetitions of pulse sequences is the repetition time(TR).
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• View the DATABASE results for 'Interpulse Times' (7).Open this link in a new window

Searchterm 'Inversion' was also found in the following services: 
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News  (1)  Resources  (2)  Forum  (13)  
 
Myocardial Late Enhancement
 
(LE) Myocardial late enhancement in contrast enhanced cardiac MRI has the ability to precisely delineate myocardial scar associated with coronary artery disease. Viability imaging implies evaluating infarcted myocardium to see whether there is enough viable tissue available for revascularization. The reversal of myocardial dysfunction is particularly relevant in patients with depressed ventricular function because revascularization improves long-term survival. In comparison to SPECT and PET imaging, myocardial late enhancement MRI demonstrates areas of delayed enhancement exactly in correlation with the infarcted region.
Viability on cardiac MRI (CMR) is based on the fact that all infarcts enhance vividly 10-15 minutes after the administration of intravenous paramagnetic contrast agents. This enhancement represents the accumulation of gadolinium in the extracellular space, due to the loss of membrane integrity in the infarcted tissue. This phenomenon of delayed hyperenhancement has been proven to correlate with the actual extent of the infarct.
MRI myocardial late enhancement can quantify the size, location and transmural extent of the infarct. If the transmural extent of the infarct (region of enhancement on MRI) is less than 50% of the wall thickness, there will be improved contractility in that segment following revascularization. In areas of hypokinesia, if there is a rim of "black" or non-infarcted myocardium that is not contracting well, it indicates the presence of hibernating myocardium, which is likely to improve after revascularization of the artery supplying that particular territory.
The total duration of a myocardial late enhancement MR imaging protocol for viability is approximately 30 minutes, including scout images, first-pass images, cine images in two planes, and delayed myocardial enhancement images. In order to assess viable myocardium, the gadolinium contrast agent is injected at a dose of 0.15 to 0.2 mmol/kg. After about 10 minutes, short axis and long axis views (see cardiac axes) of the heart are obtained using an inversion prepared ECG gated gradient echo sequence. The inversion pulse is adjusted to suppress normal myocardium. Areas of nonviable myocardium retain extremely high signal intensity, black areas show normal tissue.

For Ultrasound Imaging (USI) see Myocardial Contrast Echocardiography at Medical-Ultrasound-Imaging.com.
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• View the DATABASE results for 'Myocardial Late Enhancement' (6).Open this link in a new window

 
Further Reading:
  Basics:
A Guide To Cardiac Imaging
   by www.simplyphysics.com    
  News & More:
Prediction of Myocardial Viability by MRI
1999   by circ.ahajournals.org    
Geron Demonstrates hESC-derived cardiomyocytes improve heart function after myocardial infarction
Monday, 27 August 2007   by www.brightsurf.com    
Searchterm 'Inversion' was also found in the following services: 
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Radiology  (1) Open this link in a new windowUltrasound  (15) Open this link in a new window
Saturation Transfer
 
Nuclei can retain their magnetic orientation through a chemical reaction. Thus, if RF radiation is supplied to the spins at a frequency corresponding to the chemical shift of the nuclei in one chemical state so as to produce saturation or inversion, and chemical reactions transform the nuclei into another chemical state with a different chemical shift in a time short compared to the relaxation time, the NMR spectrum may show the effects of the saturation or inversion on the corresponding, unirradiated line in the spectrum. This technique can be used to study reaction kinetics of suitable molecules.
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• View the DATABASE results for 'Saturation Transfer' (3).Open this link in a new window

 
Further Reading:
  Basics:
Researchers create novel way to enhance MRI
Tuesday, 30 April 2013   by www.news-medical.net    
  News & More:
New Brain Imaging Technique Identifies Previously Undetected Epileptic Seizure Sites
Friday, 13 November 2015   by www.newswise.com    
MRI Resources 
Shoulder MRI - Education pool - Pregnancy - Journals - Software - General
 
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