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


Out-
      side
 



 
 'Shielded Gradient Coils' 
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 'Shielded Gradient Coils' found in 1 term [] and 3 definitions [], (+ 3 Boolean[] results
1 - 5 (of 7)     next
Result Pages : [1]  [2]
MRI Resources 
General - MR Guided Interventions - Image Quality - Directories - NMR - Portals
 
Shielded Gradient CoilsInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
Current-carrying gradient coils with reduced gradient fringe field inside of the magnet cryostat structures like cryoshields and He-vessel. The shielding can be accomplished by secondary actively driven coils or by passive screens, which are inductively coupled to the gradient coils. In both cases eddy currents outside of the gradient system will be reduced.
See also Eddy Currents.
spacer
 
• Share the entry 'Shielded Gradient Coils':  Facebook  Twitter  LinkedIn  
 
Further Reading:
  Basics:
Faraday's Law
   by hyperphysics.phy-astr.gsu.edu    
MRI Resources 
Open Directory Project - MRCP - Collections - Crystallography - Databases - PACS
 
Eddy Current ArtifactInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.
 
Quick Overview

Artifact Information
NAME Eddy current
DESCRIPTION Image distortion
REASON Induced by changes in a magnetic field
HELP Eddy current compensation, shielding

Eddy currents can cause artifacts in images and may seriously degrade overall magnet performance.


Image Guidance
Common uses to reduce the influence of eddy currents on gradient fields are eddy current compensation and shielded gradient coils (active or passive). If persistent, it must be addressed by a service representative to verify the magnet performance.
See also Eddy Current Compensation.

spacer

• View the DATABASE results for 'Eddy Current Artifact' (2).Open this link in a new window

 
Further Reading:
  Basics:
Generic Eddy Current Compensation for Rapid Magnetic Resonance Imaging(.pdf)
   by www.switt.ch    
MRI Resources 
Breast MRI - Musculoskeletal and Joint MRI - Research Labs - Service and Support - Spectroscopy - Software
 
Eddy Current Compensation
 
Eliminate Gibb's artifact (Border ringing) for sharp images. Means of reducing the influence of eddy currents on pulsed gradient fields by employing an electrical preemphasis in the gradient amplifiers. Usually multiple time constants have to be used to correct for eddy current effects in various structures of the MR system such as the cryoshields and RF-shields.
See also Eddy Currents and Shielded Gradient Coils.

spacer

• View the DATABASE results for 'Eddy Current Compensation' (4).Open this link in a new window

 
Further Reading:
  Basics:
Generic Eddy Current Compensation for Rapid Magnetic Resonance Imaging(.pdf)
   by www.switt.ch    
MRI Resources 
Knee MRI - Mobile MRI - Open Directory Project - Artifacts - Service and Support - Databases
 
Eddy CurrentsForum -
related threadsInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.
 
Electric currents induced in a conductor by a changing magnetic field or by motion of the conductor through a magnetic field.
One of the sources of concern about a potential hazard to subjects in very high magnetic fields or rapidly varying gradient or main magnetic fields. Can be a practical problem in the cryostat of superconducting magnets. Eddy currents can cause artifacts in images and may seriously degrade overall magnet performance. Common means to reduce the influence of eddy currents on gradient fields are eddy current compensation and shielded gradient coils (active or passive). See also Eddy Current Compensation.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'
spacer

• View the DATABASE results for 'Eddy Currents' (8).Open this link in a new window

 
Further Reading:
  Basics:
Electrical eddy currents in the human body: MRI scans and medical implants
   by www.phy.olemiss.edu    
Artifacts in MRI
Saturday, 1 October 2011   by www.huc.min-saude.pt    
MRI Resources 
IR - Spectroscopy pool - Used and Refurbished MRI Equipment - Bioinformatics - Contrast Agents - Libraries
 
VISART™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
From Toshiba America Medical Systems Inc.;
http://www.medical.toshiba.com/clinical/radiology/15texcelart.htm VISART™ series is a 1.5 Tesla superconducting MRI system that has been designed to meet the expanding role of MRI in today's clinical environment. The system utilizes innovative technologies such as digital RF, high speed actively shielded gradients and optimized RF coils, which support a wide range of MRI developments. The Visart, an early type of Toshiba Medical Systems Inc., can be retrofitted or upgraded to the Excelart configuration.
Device Information and Specification
CLINICAL APPLICATION Whole body
CONFIGURATION Compact
SURFACE COILS Quadrature, solenoid and multi-channel configurations
SYNCHRONIZATION ECG/peripheral optional, respiratory gating
PULSE SEQUENCES SE, FE, IR, FastSE, FastIR, FastFLAIR, Fast STIR, FastFE, FASE, Hybrid EPI, Multi Shot EPI; Angiography: 2D(gate/non-gate)/3D TOF, SORS-STC
IMAGING MODES Single, multislice, volume study
MAGNET TYPE Superconducting
POWER REQUIREMENTS 380/400/415/440/480 V
COOLING SYSTEM TYPE Closed-loop water-cooled
FIELD STRENGTH 1.5 T
STRENGTH 25 mT/m
SHIMMING Passive, active
spacer

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

 
Further Reading:
  News & More:
Angio, cardiac imaging top list for MR and CT
1999   by www.diagnosticimaging.com    
MRI Resources 
Homepages - Libraries - Abdominal Imaging - Chemistry - Blood Flow Imaging - Developers
 
     1 - 5 (of 7)     next
Result Pages : [1]  [2]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



In 2075 (after about 100 years of ...) the MRI scan will be :
obsolete 
done with handheld probe 
done at home (app, ...) 
a 3 second walk through 
daily done 
replaced by something much ... 

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. [ 21 January 2017]
Terms of Use | Privacy Policy | Advertising
 [last update: 2017-01-13 03:47:00]