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

Out-
      side
 



 
 'Low Field MRI' 
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 'Low Field MRI' found in 1 term [] and 7 definitions [], (+ 17 Boolean[] results
previous     16 - 20 (of 25)     next
Result Pages : [1]  [2]  [3 4 5]
Searchterm 'Low Field MRI' was also found in the following services: 
spacer
News  (14)  Resources  (5)  Forum  (1)  
 
Legal Requirements
 
mri safety guidance
MRI Safety Guidance
The owner of MRI equipment has to ensure that the equipment does fulfill the local requirements.
In some countries, the requirements are more stringent than in others; in other countries, they are nonexistent.
The user in general is unable to check power output, gradient strength, or even field strength. The manufacturer has to cover authorized hardware and software updates after the initial installation and has to give guarantee for the requirements. Specially designed computer programs usually supervise the power output of MRI devices and will not allow or will interrupt any imaging or spectroscopy procedure exceeding those limits considered safe.

See also European Medicines Agency, FDA information:
www.fda.gov/cdrh/safety/mrisafety.html
spacer
• For this and other aspects of MRI safety see our InfoSheet about MRI Safety.
• Patient-related information is collected in our MRI Patient Information.

 
Further Reading:
  News & More:
A Primer on Medical Device Interactions with Magnetic Resonance Imaging Systems
   by govpulse.us    
MRI Safety Resources 
Safety Training - Guidance - Safety Products - Stimulator pool - Claustrophobia
 
MRI History
 
•
Sir Joseph Larmor (1857-1942) developed the equation that the angular frequency of precession of the nuclear spins being proportional to the strength of the magnetic field. [Larmor relationship]
•
In the 1930's, Isidor Isaac Rabi (Columbia University) succeeded in detecting and measuring single states of rotation of atoms and molecules, and in determining the mechanical and magnetic moments of the nuclei.
•
Felix Bloch (Stanford University) and Edward Purcell (Harvard University) developed instruments, which could measure the magnetic resonance in bulk material such as liquids and solids. (Both honored with the Nobel Prize for Physics in 1952.) [The birth of the NMR spectroscopy]
•
In the early 70's, Raymond Damadian (State University of New York) demonstrated with his NMR device, that there are different T1 relaxation times between normal and abnormal tissues of the same type, as well as between different types of normal tissues.
•
In 1973, Paul Lauterbur (State University of New York) described a new imaging technique that he termed Zeugmatography. By utilizing gradients in the magnetic field, this technique was able to produce a two-dimensional image (back-projection). (Through analysis of the characteristics of the emitted radio waves, their origin could be determined.) Peter Mansfield further developed the utilization of gradients in the magnetic field and the mathematically analysis of these signals for a more useful imaging technique. (Paul C Lauterbur and Peter Mansfield were awarded with the 2003 Nobel Prize in Medicine.)
•
In 1975, Richard Ernst introduced 2D NMR using phase and frequency encoding, and the Fourier Transform. Instead of Paul Lauterbur's back-projection, he timely switched magnetic field gradients ('NMR Fourier Zeugmatography'). [This basic reconstruction method is the basis of current MRI techniques.]
•
1977/78: First images could be presented. A cross section through a finger by Peter Mansfield and Andrew A. Maudsley. Peter Mansfield also could present the first image through the abdomen.
•
In 1977, Raymond Damadian completed (after 7 years) the first MR scanner (Indomitable). In 1978, he founded the FONAR Corporation, which manufactured the first commercial MRI scanner in 1980. Fonar went public in 1981.
•
1981: Schering submitted a patent application for Gd-DTPA dimeglumine.
•
1982: The first 'magnetization-transfer' imaging by Robert N. Muller.
•
In 1983, Toshiba obtained approval from the Ministry of Health and Welfare in Japan for the first commercial MRI system.
•
In 1984, FONAR Corporation receives FDA approval for its first MRI scanner.
•
1986: Jürgen Hennig, A. Nauerth, and Hartmut Friedburg (University of Freiburg) introduced RARE (rapid acquisition with relaxation enhancement) imaging. Axel Haase, Jens Frahm, Dieter Matthaei, Wolfgang Haenicke, and Dietmar K. Merboldt (Max-Planck-Institute, Göttingen) developed the FLASH (fast low angle shot) sequence.
•
1988: Schering's MAGNEVIST gets its first approval by the FDA.
•
In 1991, fMRI was developed independently by the University of Minnesota's Center for Magnetic Resonance Research (CMRR) and Massachusetts General Hospital's (MGH) MR Center.
•
From 1992 to 1997 Fonar was paid for the infringement of it's patents from 'nearly every one of its competitors in the MRI industry including giant multi-nationals as Toshiba, Siemens, Shimadzu, Philips and GE'.
•
 
Images, Movies, Sliders:
 Cardiac Infarct Short Axis Cine Overview  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 
spacer

• View the DATABASE results for 'MRI History' (6).Open this link in a new window


• View the NEWS results for 'MRI History' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Magnetic Resonance Imaging, History & Introduction
2000   by www.cis.rit.edu    
A Short History of the Magnetic Resonance Imaging (MRI)
   by www.teslasociety.com    
Fonar Our History
   by www.fonar.com    
  News & More:
Scientists win Nobels for work on MRI
Tuesday, 10 June 2003   by usatoday30.usatoday.com    
2001 Lemelson-MIT Lifetime Achievement Award Winner
   by web.mit.edu    
MRI's inside story
Thursday, 4 December 2003   by www.economist.com    
MRI Resources 
Anatomy - Education - Cochlear Implant - PACS - Cardiovascular Imaging - Claustrophobia
 
Virgoâ„¢InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.canamglobal.com/mri/virgomri.html From Millennium Technology Inc. This open C-shaped MRI system eases patient comfort and technologist maneuverability. This low cost scanner is build for a wide range of applications. The Virgo™ patient table is detachable and moves on easy rolling castors. Able to accommodate patient weights up to 160 kg, the tabletop has a range of motion of 30 cm in the lateral direction and 90cm in the longitudinal direction. Images generated with this scanner can only be viewed (without data loss) on Millennium's proprietary viewing software.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
C shaped
SYNCHRONIZATION
Standard cardiac gating, ECG/peripheral, respiratory gating
PULSE SEQUENCES
2D Spin Echo (single and multi-echo), 2D Inversion Recovery, 2D Sequential and 3D Volume Gradient Echo, 2D and 3D Spoiled Gradient Echo
IMAGING MODES
Localizer, single slice, multislice, volume, fast, POMP, multi slab, cine, slice and frequency zip, extended dynamic range, tailored RF
TR
steps of 1 msec
TE
steps of 1 msec
SINGLE/MULTI SLICE
Simultaneous scan and reconstruction;; 100 images/second reconstruction
400 mm
2D : 2 mm; 3D : 0.5 mm
MEASURING MATRIX
512x512
PIXEL INTENSITY
256 gray levels
MAGNET TYPE
Permanent
BORE DIAMETER
or Vertical Gap
44 cm
STRENGTH
15 mT/m
5-GAUSS FRINGE FIELD
3 m/3 m
Passive
spacer
Searchterm 'Low Field MRI' was also found in the following services: 
spacer
News  (14)  Resources  (5)  Forum  (1)  
 
G-SCANInfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.esaote.de/04_kernspin/gscan/gscan.htm From Esaote S.p.A.; Esaote introduced the new G-SCAN at the RSNA in Dec. 2004. The G-SCAN covers almost all musculoskeletal applications including the spine. The tilting gantry is designed for scanning in weight-bearing positions. This unique MRI scanner is developed in line with the Esaote philosophy of creating high quality MRI systems that are easy to install and that have a low breakeven point.
Device Information and Specification
CLINICAL APPLICATION
CONFIGURATION
Spine, extremity, shoulder, flex coil, knee dual phased array, ankle//foot dual phased array, hand//wrist dual phased array
PULSE SEQUENCES
SE, GE, IR, STIR, TSE, 3D CE, GE-STIR, 3D GE, ME, TME, HSE
IMAGING MODES
Single, multislice, volume study, fast scan, multi slab, cine
FOV
100 up to 350 mm, 25 mm displayed
512 x 512
MEASURING MATRIX
256 x 256 maximum
MAGNET TYPE
Permanent
BORE DIAMETER
or W x H
33 cm H, open
POWER REQUIREMENTS
100/110/200/220/230/240 V
STRENGTH
25 mT/m
5-GAUSS FRINGE FIELD
180 cm
Passive
spacer

• View the DATABASE results for 'G-SCAN' (3).Open this link in a new window

MRI Resources 
Chemistry - Spectroscopy pool - Societies - RIS - Universities - Shoulder MRI
 
Signa HDe 1.5Tâ„¢InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.
 
www.vitalcom.com/euen/mri/products/signa-hde-15t/index.html From GE Healthcare;
GE Healthcare has added the Signa HDe 1.5T™, a compact MRI device at an affordable price to its family of MRI products. It has a single electronic cabinet that can be positioned inside the scanner room rather than in a separate equipment room. The Signa HDe 1.5T can be installed in the same physical location as 0.5T MRI systems with minimal construction costs. According to GE, the installation has been simplified to last only 7 days and has a 30 percent smaller footprint than a typical 1.5T system.
The 1.5T Signa™ HDe MRI system is substantially equivalent to the currently marketed GE 1.5T machines. The data acquisition system supports 1, 4, 8 independent receive channels and multiple independent coil elements per channel during a single acquisition series. The gradient specifications of HDe are lower than other GE Signa 1.5T MRI systems, but it can support clinical applications in cardiac and spectroscopy imaging.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Compact short bore
Head and body coil standard; all other coils optional e.g., abdomen, spine, breast, knee, shoulder, cardiac imaging coils
Possible
SYNCHRONIZATION
ECG/peripheral, respiratory gating, (SmartPrep, SmartStep)
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
IMAGING MODES
2D single slice, multi slice, and 3D volume images, multi slab, cine
1 cm to 48 cm continuous
2D 0.7 mm to 20 mm; 3D 0.1 mm to 5 mm
1028 x 1024
MEASURING MATRIX
128x512 steps 32 phase encode
PIXEL INTENSITY
256 gray levels
POWER REQUIREMENTS
480 or 380/415
COOLING SYSTEM TYPE
Closed-loop water-cooled gradient
CRYOGEN USE, L/hr
less than 0.03 L/hr liquid helium
spacer

• View the NEWS results for 'Signa HDe 1.5Tâ„¢' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Signa HDe 1.5T
   by www.gehealthcare.com/    
MRI Resources 
Spine MRI - Developers - Manufacturers - Mass Spectrometry - MRI Technician and Technologist Jobs - Health
 
previous      16 - 20 (of 25)     next
Result Pages : [1]  [2]  [3 4 5]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



Personalized protocols (age, gender, body habitus, etc.) lead to :
more automated planning 
improved patient comfort 
better diagnostics 
optimized image quality 
nothing 

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