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

Out-
      side
 



 
 'Passive Shimming' 
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 'Passive Shimming' found in 1 term [] and 3 definitions [], (+ 17 Boolean[] results
1 - 5 (of 21)     next
Result Pages : [1]  [2 3 4 5]
MRI Resources 
Liver Imaging - Collections - MR Myelography - Spectroscopy pool - Resources - Safety Training
 
Passive Shimming
 
Shimming by adjusting the position of suitable pieces of ferromagnetic metal within or around the main magnet of a MRI system. Typically, the iron is in the form of small plates which are held in removable trays. The magnetic field is plotted, the position and quality of the iron required is then calculated and the appropriate 'shims' put in place. Several repetitions of this process will normally be required in order to achieve the optimum arrangement.
Passive shimming does not replace adjustable shimming, but is installed during the commissioning of a unit to improve the homogeneity of the bare magnet.
spacer
 
• Share the entry 'Passive Shimming':  Facebook  Twitter  LinkedIn  
MRI Resources 
Raman Spectroscopy - MRI Training Courses - Spectroscopy - Brain MRI - Service and Support - MRI Reimbursement
 
ShimmingForum -
related threads
 
Correction of inhomogeneity of the magnetic field produced by the main magnet of a MRI system due to imperfections in the magnet or to the presence of external ferromagnetic objects. May involve changing the configuration of the magnet or the using of shim coils (active shimming) or adding or removing steel from the magnets poles (passive shimming) to fine-tune the magnetic field.

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

• View the DATABASE results for 'Shimming' (71).Open this link in a new window

 
Further Reading:
  News & More:
Implementation of Dual-Source RF Excitation in 3 T MR-Scanners Allows for Nearly Identical ADC Values Compared to 1.5 T MR Scanners in the Abdomen
Wednesday, 29 February 2012   by www.plosone.org    
MRI Resources 
Portals - MRI Technician and Technologist Career - Bioinformatics - IR - Examinations - Collections
 
Signa OpenSpeed™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.gehealthcare.com/usen/mr/open_speed/index.html From GE Healthcare;
a friendly and less confining appearance targets the 7% of individuals who refuse to have an MRI because of claustrophobia. This open MRI system is also up to three times faster than other scanners, therefore the Signa OpenSpeed™ reducing exam time and scheduling issues. In addition, a swing table provides better access and supports up to 500 pounds.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Integrated transmit and receive body coil; 4 channel head array, 8 channel CTL array, 2 channel shoulder array, 3 channel large extremity array, 3 channel small extremity array, 4 channel foot array, 3 channel wrist array, 4 channel breast array
SYNCHRONIZATION
Standard cardiac gating, ECG/peripheral, respiratory gating
PULSE SEQUENCES
Standard: SE, IR, 2D/3D GRE and SPGR, Angiography: 2D/3D TOF, 2D/3D Phase Contrast;; 2D/3D FSE, 2D/3D FGRE and FSPGR, SSFP, FLAIR, EPI, optional: 2D/3D Fiesta, FGRET, Spiral, Tensor
IMAGING MODES
Localizer, single slice, multislice, volume, fast, POMP, multi slab, cine
TR
1.3 to 12000 msec in increments of 1 msec
TE
0.4 to 2000 msec in increments of 1 msec
SINGLE/MULTI SLICE
Simultaneous scan and reconstruction;; 100 images/second with Reflex 100
1cm to 40 cm continuous
2D: 0.8mm - 20mm 3D: 0.1mm - 20mm
1280 x 1024
MEASURING MATRIX
128x512 steps 32 phase//freq.
PIXEL INTENSITY
256 gray levels
0.08 mm; 0.02 mm optional
175 x 85 x 447 cm
MAGNET WEIGHT
8256 kg
H*W*D
530 x 175 x 250 cm
POWER REQUIREMENTS
200 - 480, 3-phase
COOLING SYSTEM TYPE
Liquid helium
0.03 L/hr, holds 300 L
STRENGTH
25 mT/m
5-GAUSS FRINGE FIELD
4.7 m/ 3.8 m
Computerized passive shimming during magnet setup, autoshim per series with automatic table motion to magnet isocenter for each prescription
spacer

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

 
Further Reading:
  News & More:
MR Surgical Suite, Improving surgical procedure quality (.pdf)
   by www3.gehealthcare.com    
MRI Resources 
Bioinformatics - Jobs - Mass Spectrometry - Open Directory Project - Distributors - Implant and Prosthesis
 
Signa Ovation™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.gehealthcare.com/usen/mr/ovation/index.html From GE Healthcare;
the Signa Ovation™ is a patient-friendly open MRI scanner designed not only to handle a typical patient mix, but to accommodate larger patients, patients who are claustrophobic, and others who have difficulty tolerating the close quarters of conventional MR machines.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Integrated transmit and receive body coil; head coil, 4 channel neurovascular array, 8 channel CTL array, 2 channel shoulder array, 3 channel large extremity array, 3 channel small extremity array, 4 channel foot array, 3 channel wrist array
SYNCHRONIZATION
Standard cardiac gating, ECG/peripheral, respiratory gating
PULSE SEQUENCES
Standard: SE, IR, 2D/3D GRE and SPGR, 2D/3D TOF, 2D/3D FSE, 2D/3D FGRE and FSPGR, SSFP, FLAIR, EPI, optional: 2D/3D Fiesta, true chem sat, fat/water separation, single shot diffusion EPI, line scan diffusion
IMAGING MODES
Localizer, single slice, multislice, volume, fast, POMP, multi slab, cine, slice and frequency zip, extended dynamic range, tailored RF
TR
1.3 to 12000 msec in increments of 1 msec
TE
0.4 to 2000 msec in increments of 1 msec
SINGLE/MULTI SLICE
Simultaneous scan and reconstruction;; 80 images/second reconstruction
3cm to 40 cm continuous
2D: 1.4mm - 20mm 3D: 0.2mm - 20mm
1280 x 1024
MEASURING MATRIX
128x512 steps 32 phase//freq.
PIXEL INTENSITY
256 gray levels
0.08 mm; 0.02 mm optional
MAGNET TYPE
Permanent
175 x 85 x 447 cm
MAGNET WEIGHT
19200 kg
H*W*D
530 x 175 x 250 cm
POWER REQUIREMENTS
200 - 480, 3-phase
GRADIENT COOLING
None
MAX. GRADIENT AMPLITUDE
19 mT/m
5-GAUSS FRINGE FIELD
2.5 m/2.5 m
Computerized passive shimming during magnet setup, autoshim per series with automatic table motion to magnet isocenter for each prescription
spacer

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

MRI Resources 
Education - Spectroscopy pool - Non-English - Education pool - Equipment - Nerve Stimulator
 
Upright™ MRIInfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.fonar.com/standup.htm www.fonar.com/standup.htm www.fonar.com/standup.htm From FONAR Corporation;
in October of 2004, the company changed the product name of the Stand-Up™ MRI to the Upright™ MRI. The Indomitable™, Upright™ MRI is the only open MRI in the world that can perform positional MRI (pMRI), i.e. the Upright MRI™ scans patients in upright, weight-bearing positions, in addition to the conventional lie-down positions. The Upright™ MRI is the only device that can scan patients in the position their symptoms occur, in their position of pain. In early clinical reports independently confirm the effectiveness and potential of positional MRI. In October 2000, Fonar received permission to market the Indomitable™ from the FDA.
Device Information and Specification
CLINICAL APPLICATION
Whole body - weight-bearing MRI - position imaging (flexion, extension, bending, standing, sitting and recumbent scanning)
CONFIGURATION
Front-open and Top-open MRI
Solenoid ("Wrap-around") and planar RF receiver coils
SINGLE/MULTI SLICE
0.1 sec per slice
MULTISLICE
0.1 sec per slice
Min. 6.0 cm
Min. 0.8 mm (3DFT)
MEASURING MATRIX
128 - 512
MAGNET TYPE
Iron-frame electromagnet
45.72 cm horizontal
POWER REQUIREMENTS
380/400/415/440/480 V
COOLING SYSTEM TYPE
Water, closed-loop
CRYOGEN USE, L/hr
-
STRENGTH
12 mT/m
5 GAUSS FRINGE FIELD, radial/axial
active, passive
spacer

• View the DATABASE results for 'Upright™ MRI' (5).Open this link in a new window


• View the NEWS results for 'Upright™ MRI' (9).Open this link in a new window.
 
Further Reading:
  Basics:
Product Information - Fonar Corporation
  News & More:
Landmark Independent Study by UCLA School of Medicine Reports Comparison of Dynamic™ Upright® MRI With Static Upright MRI in More Than 1,000 Patients (1,302):
Thursday, 15 November 2007   by www.fonar.com    
FONAR Wins The Wall Street Journal Technology Innovation Award For 2007 For the FONAR UPRIGHT™ Multi-Position™ MRI
Monday, 1 October 2007   by www.fonar.com    
MRI Resources 
Blood Flow Imaging - DICOM - Implant and Prosthesis pool - Pacemaker - Breast Implant - Cochlear Implant
 
     1 - 5 (of 21)     next
Result Pages : [1]  [2 3 4 5]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



Next big thing in MRI will be :
AI 
remote operator 
personalized protocols 
helium-free 
molecular MRI 
portable MRI 

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]