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


Out-
      side
 



 
 'Excitation' 
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
Result : Searchterm 'Excitation' found in 10 terms [] and 86 definitions []
1 - 5 (of 96)     next
Result Pages : [1 2]  [3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]
Searchterm 'Excitation' was also found in the following services: 
spacer
News  (1)  Forum  (11)  
 
Excitation
 
Sent (inducing, transferring) energy into the 'spinning' nuclei via radio frequency pulse, which puts the nuclei into a higher energy state. By producing a net transverse magnetization a MRI system can observe a response from the excited system.
spacer
 
• Share the entry 'Excitation':  Facebook  Twitter  LinkedIn  
 
• Related Searches:
    • Echo
    • Number of Signal Averages
    • Radio Frequency Pulse
    • Fractional Nex Imaging
    • Transverse Magnetization
 
Further Reading:
  Basics:
Tech Spotlight: How to calibrate an MRI RF amplifier
Saturday, 1 December 2012   by medicaldesign.com    
Musculoskeletal MRI at 3.0 T: Relaxation Times and Image Contrast
Sunday, 1 August 2004   by www.ajronline.org    
IMAGE CONTRAST IN MRI(.pdf)
   by www.assaftal.com    
Searchterm 'Excitation' was also found in the following services: 
spacer
Radiology  (5) Open this link in a new windowUltrasound  (6) Open this link in a new window
Selective Excitation
 
Controlling the frequency spectrum (bandwidth) of a RF pulse (via tailoring) while imposing a magnetic field gradient on spins, such that only a desired region will have an appropriate resonant frequency to be excited.
Originally used to excite all but a desired region; now often used to select only a desired region, such as a plane, for excitation. Used without simultaneous magnetic field gradients, tailored RF pulses can be used to selectively excite a particular spectral line or group of lines. RF and gradient pulse combinations can be designed to select both spatial regions and spectral frequencies.
spacer

• View the DATABASE results for 'Selective Excitation' (17).Open this link in a new window

MRI Resources 
Image Quality - Libraries - Chemistry - DICOM - MRI Technician and Technologist Jobs - Mobile MRI
 
Number of Excitations
 
(NEX) How many times each line of k-space data is acquired during the scan.
See also Signal Averaging.
spacer

• View the DATABASE results for 'Number of Excitations' (5).Open this link in a new window

 
Further Reading:
  Basics:
MRI Artifacts: Mechanism and Control
   by ric.uthscsa.edu    
Diffusion-Weighted MRI in the Body: Applications and Challenges in Oncology
Friday, 1 June 2007   by www.ajronline.org    
Searchterm 'Excitation' was also found in the following services: 
spacer
News  (1)  Forum  (11)  
 
Cross Excitation ArtifactInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Energy transfer to nearby slices by the RF pulse.
See Crosstalk Artifact.
spacer
Searchterm 'Excitation' was also found in the following services: 
spacer
Radiology  (5) Open this link in a new windowUltrasound  (6) Open this link in a new window
Volume Selective Excitation
 
The selective excitation of spins in only a limited region of space. This can be particularly useful for spectroscopy as well as imaging. Spatial localization of the signal source may be achieved through spatially selective excitation and the resulting signal may be analyzed directly for the spectrum corresponding to the excited region. It is usually achieved with selective excitation.
Typically, a single dimension of localization can be achieved with one selective RF excitation pulse (and a magnetic field gradient along a desired direction), while a localized volume (3D) can be excited with a stimulated echo produced with three selective RF pulses whose selective magnetic field gradients are mutually orthogonal, having a common intersection in the desired region. Similar 'crossed plane' excitation can be used with selective 180° refocusing pulses and conventional spin echoes.
A degree of spatial localization of excitation can alternatively be achieved with depth pulses, e.g. when using surface coils for excitation as well as signal detection. An indirect application of selective excitation for volume-selected spectroscopy is to use appropriate combinations of signals acquired after selective inversion of different regions, in order to subtract away the signal from undesired regions.
spacer

• View the DATABASE results for 'Volume Selective Excitation' (3).Open this link in a new window

MRI Resources 
Supplies - MRI Accidents - IR - MR Myelography - Process Analysis - Raman Spectroscopy
 
     1 - 5 (of 96)     next
Result Pages : [1 2]  [3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



In 2020 your scanner will probably work with a field strength of :
lower 
1T 
1.5T 
2T 
3T 
7T 
higher 

Look
      Ups





Magnetic Resonance - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • US-TIP • The-Medical-Market
Copyright © 2003 - 2016 SoftWays. All rights reserved. [ 19 January 2017]
Terms of Use | Privacy Policy | Advertising
 [last update: 2017-01-13 03:47:00]