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

Out-
      side
 



 
 'Quadrature Detector' 
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 'Quadrature Detector' found in 1 term [] and 6 definitions [], (+ 1 Boolean[] results
previous     6 - 8 (of 8)     
Result Pages : [1]  [2]
MRI Resources 
Resources - Brain MRI - MRI Technician and Technologist Schools - Functional MRI - Anatomy - Online Books
 
Radio Frequency Quadrature ArtifactInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Quick Overview
Artifact Information
NAME
Radio frequency quadrature
DESCRIPTION
Bright spot in the center of the image, ghosting
REASON
RF detection circuitry problem
HELP
Call the service
Radio frequency quadrature artifacts occur when the detector channels of the quadrature detector are disturbed.
A DC offset of one amplifier output can e.g., produce a bright point in the center of the field of view (see also central point artifact), or a higher gain of one detector channel can generate diagonally ghosting.
mri safety guidance
Image Guidance
Radio frequency quadrature artifacts are technical faults and must be eliminated by the service.
spacer
 
Further Reading:
  News & More:
Magnetic Resonance Imaging (MRI)
2003   by www.hull.ac.uk    
MRI Resources 
Raman Spectroscopy - Examinations - MRA - Mass Spectrometry - Coils - Stimulator pool
 
Real Signal
 
In phase component of signal detected with a quadrature detector.
spacer
MRI Resources 
Health - MRI Technician and Technologist Schools - Colonography - Cochlear Implant - Homepages - Case Studies
 
Bird Cage CoilInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
A RF coil, often a transmit receive coil with a number of wires running along the z-direction, arranged to give a cosine current variation around the circumference of the coil, which looks like a bird cage. The bird cage coil works on a different principle to conventionally tuned local and surround coils in that it behaves like a tuned transmission line with one complete cycle of standing wave around the circumference. The frequency supply is generated by an oscillator, which is modulated to form a shaped pulse by a product detector controlled by the waveform generator. The signal must be amplified to 1000's of watts. This can be done using either solid state electronics, valves or a combination of both.
The bird cage coil design provides the best field homogeneity of all RF imaging coils.
One advantage is that it is simple to produce an exceedingly uniform B1 radio frequency field over most of the coil's volume, with the result of images with a high degree of uniformity.
A second advantage is that nodes with zero voltage occur 90° away from the driven part of the coil, thus facilitating the introduction of a second signal in quadrature, which produces a circularly polarized radio frequency field.
This type of volume coil is used for brain (head) MRI, or MR imaging of joints, such as the wrist or knees.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'
 
Images, Movies, Sliders:
 Brain MRI Images T1  Open this link in a new window
 Anatomic MRI of the Knee 1  Open this link in a new window
    
SlidersSliders Overview

 MRI of the Brain Stem with Temoral Bone and Auditory System  Open this link in a new window
    
SlidersSliders Overview

 
spacer

• View the DATABASE results for 'Bird Cage Coil' (4).Open this link in a new window

 
Further Reading:
  Basics:
HEAD AND NECK MRI GRADIENT COIL DESIGN
Thursday, 26 August 1999   by www.imaging.robarts.ca    
System Architecture
2003   by www.revisemri.com    
  News & More:
On the Horizon - Next Generation MRI
Wednesday, 23 October 2013   by thefutureofthings.com    
TOSHIBA INTRODUCES 32 ELEMENT COILS FOR ITS VANTAGE TITAN MR SYSTEMS
Tuesday, 9 November 2010   by medical.toshiba.com    
MRI Resources 
MRI Training Courses - Resources - Spectroscopy pool - Functional MRI - Safety Training - Databases
 
previous      6 - 8 (of 8)     
Result Pages : [1]  [2]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



New acceleration techniques will :
reduce scan times 
cause artifacts 
increase expenses 
be useful if you have a lot of experience 
doesn't do much 
never heard of 

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. [ 27 April 2024]
Terms of Use | Privacy Policy | Advertising
 [last update: 2024-02-26 03:41:00]