Magnetic Resonance - Technology Information Portal Welcome to MRI Technology
Info
  Sheets

Out-
      side
 



 
 MRI Database 
SEARCH FOR    
  2 3 5 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
previous     56 - 60 (of 83)     next 
R--Ra   Ra-Ra   Ra-Ra   Ra-Ra   Ra-Ra   Ra-Re   Re-Re   Re-Re   Re-Re   Re-Re   Re-Re   Re-Re     Re-Re   Re-Re   Re-Re   RF-Ro   Ro-Ro   
MRI Resources 
Lung Imaging - Crystallography - Research Labs - Safety Products - Abdominal Imaging - Health
 
Rephasing
 
The process of returning out of phase magnetic moments back into phase coherence. Caused either by rapidly reversing a magnetic gradient (Field Echo) or by applying a 180° RF pulse (Spin Echo). In the spin echo pulse sequence this action effectively cancels out the spurious T2* information from the signal.

See also Spin Echo Sequence and Gradient Echo Sequence.
spacer

• View the DATABASE results for 'Rephasing' (21).Open this link in a new window

Rephasing Gradient
 
Magnetic field gradient pulse applied to reverse the spatial variation of phase of transverse magnetization caused by a dephasing gradient. For example, in selective excitation, it is a magnetic field gradient applied for a brief period after a selective excitation pulse, in the opposite direction to the gradient used for the selective excitation. The result of the gradient reversal is a rephasing of the spins (which will have gotten out of phase with each other along the direction of the selection gradient), forming a gradient echo and improving the sensitivity of imaging after the selective excitation process.
spacer
MRI Resources 
Fluorescence - Safety pool - Pediatric and Fetal MRI - Health - DICOM - Raman Spectroscopy
 
Resistive Magnet
 
A type of magnet that utilizes the principles of electromagnetism to generate the magnetic field. Typically large current values and significant cooling of the magnet coils is required. The resistive magnet does not require cryogens, but needs a constant power supply to maintain a homogenous magnetic field, and can be quite expensive to maintain.
Resistive magnets fall into two general categories - iron-core and air-core.
Iron-core electromagnets provide the advantages of a vertically oriented magnetic field, and a limited fringe field with little, if any, missile effects due to the closed iron-flux return path.
Air-core electromagnets exhibit horizontally oriented fields, which have large fringe fields (unless magnetically shielded) and are prone to missile effects. Resistive magnets are typically limited to maximum field strengths of approximately 0.6T.
spacer

• View the DATABASE results for 'Resistive Magnet' (3).Open this link in a new window

ResolutionForum -
there are related threads
 
Resolution is a function of slice thickness, field of view (FOV) and matrix size. The resolution in plane is a function of FOV / matrix size.
spacer

• View the NEWS results for 'Resolution' (10).Open this link in a new window.

• View the DATABASE results for 'Resolution' (150).Open this link in a new window

 
Further Reading:
  Basics:
Micro-MRI Principles, Strengths, and Weaknesses
Tuesday, 10 January 2017   by www.news-medical.net    
  News & More:
High-resolution MRI enables direct imaging of neuronal activity - DIANA – direct imaging of neuronal activity
Friday, 18 November 2022   by physicsworld.com    
Deep learning-based single image super-resolution for low-field MR brain images
Saturday, 16 April 2022   by www.nature.com    
A Comparison of Methods for High-Spatial-Resolution Diffusion-weighted Imaging in Breast MRI
Tuesday, 25 August 2020   by pubs.rsna.org    
Resolution Element
 
Size of smallest spatially resolved regions in an image. It may be anisotropic, e.g. with an asymmetric acquisition matrix or slice thickness, and may be larger than the pixel or voxel.
spacer

• View the DATABASE results for 'Resolution Element' (2).Open this link in a new window

 
Further Reading:
  News & More:
Micro-MRI Principles, Strengths, and Weaknesses
Tuesday, 10 January 2017   by www.news-medical.net    
MRI Resources 
Contrast Agents - Crystallography - Intraoperative MRI - General - MRA - Research Labs
 
previous       56 - 60 (of 83)      next 
R--Ra   Ra-Ra   Ra-Ra   Ra-Ra   Ra-Ra   Ra-Re   Re-Re   Re-Re   Re-Re   Re-Re   Re-Re    Re-Re    Re-Re   Re-Re   Re-Re   RF-Ro   Ro-Ro   
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

MR-TIP    
Community   
User
Pass
Forgot your UserID/Password ?    



How AI will impact MRI :
only diagnostics 
saving time 
reducing cost 
makes planning obsolete 
reduce human knowledge 
not at all 

Look
      Ups





MR-TIP.com uses cookies! By browsing MR-TIP.com, you agree to our use of cookies.

Magnetic Resonance - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • Medical-Ultrasound-Imaging • 
Copyright © 2003 - 2024 SoftWays. All rights reserved. [ 29 March 2024]
Terms of Use | Privacy Policy | Advertising
 [last update: 2024-02-26 03:41:00]