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

Out-
      side
 



 
 'Magnet' 
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 'Magnet' found in 97 terms [] and 515 definitions []
previous     31 - 35 (of 612)     next
Result Pages : [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]  [ ... ]
Searchterm 'Magnet' was also found in the following services: 
spacer
News  (897)  Resources  (213)  Forum  (82)  
 
Magnetic Resonance
 
(MR) Resonance phenomenon resulting in the absorption and/or emission of electromagnetic energy by nuclei (for that reason also nuclear magnetic resonance) or electrons in a static magnetic field, after excitation by a suitable RF magnetic field.
The peak resonance frequency is proportional to the magnetic field, and is given by the Larmor equation. Only unpaired electrons or nuclei with a spin exhibit magnetic resonance. The absorption or emission of energy by atomic nuclei in an external magnetic field after the application of RF excitation pulses using frequencies, which satisfy the conditions of the Larmor equation.
The magnetic resonance phenomenon may be used in one of these ways:
By manipulation of the external field (application of gradient fields), the resonance frequency can become dependent on spatial location, and hence images may be generated (MRI).
The effect of the electron cloud in any atom or molecule is to slightly shield the nucleus from the external field, thus giving any chemical species a characteristic frequency. This gives rise to 'spectra' where nuclei in a molecule give rise to specific signals, thus facilitating the detection of individual chemicals by means of their frequency spectra (MRS)
spacer
 
• Related Searches:
    • Functional Magnetic Resonance Imaging
    • Spin
    • Nuclear Magnetic Resonance Imaging
    • MRI History
    • Larmor Frequency
 
Further Reading:
  Basics:
Magnetic Resonance Imaging, History & Introduction
2000   by www.cis.rit.edu    
  News & More:
The 2003 Nobel Prize in Physiology or Medicine
2003   by www.nobel.se    
Searchterm 'Magnet' was also found in the following services: 
spacer
Radiology  (44) Open this link in a new windowUltrasound  (33) Open this link in a new window
Magnetic Shielding
 
Means to confine the region of strong magnetic field surrounding a magnet; most commonly the use of material with high permeability (passive shielding) or by employing secondary counteracting coils outside of the primary coils (active shielding). The high permeability material can be employed in the form of a yoke immediately surrounding the magnet (self-shielding) or installed in the walls of a room as full or partial room-shielding. Unlike shielding ionizing radiation, for example, magnetic shielding can only be accomplished by forcing the unavoidable magnetic return flux through more confined areas or structures, not by absorbing it.

See also Radio Frequency Shielding Radio Frequency Shielding, and Faraday cage.

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

• View the DATABASE results for 'Magnetic Shielding' (11).Open this link in a new window

 
Further Reading:
  Basics:
Faraday's Law
   by hyperphysics.phy-astr.gsu.edu    
  News & More:
Magnetic Sensitivity of MRI Systems to External Iron: The Design Process
   by www.integratedsoft.com    
MRI Resources 
Collections - Pacemaker - Portals - Breast MRI - Blood Flow Imaging - Bioinformatics
 
MAGNETOM Avantoâ„¢InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
test.med.siemens.com/magnetom/rsna_chicago_2003/tim/avanto/index.php From Siemens Medical Systems; MAGNETOM Avanto with Tim - Total imaging matrix technology. For true whole-body anatomical coverage. For ultra-fast image acquisition. Aids the physician in fast and precise evaluation of systemic diseases like colon cancer, metastasis imaging, vessel diseases, and preventional exams. For claustrophobic patients, MAGNETOM Avanto enables feetfirst exams for nearly all MR procedures. For obese patients, MAGNETOM Avanto supports up to 200 kg (400 lbs), without table movement restrictions. The AudioComfort technology enables up to a 30 dB(A) acoustic noise reduction, that means nearly all clinical routine sequences are running under 99 dB(A).
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Compact short bore
Body, Tim [32 x 8], Tim [76 x18], Tim [76 coil elements with up to 32 RF channels]
Yes/SVS or CSI opt.
SYNCHRONIZATION
ECG/peripheral, respiratory gating
PULSE SEQUENCES
GRE, IR, FIR, STIR, TrueIR/FISP, FSE, FLAIR, MT, SS-FSE, MT-SE, MTC, MSE, EPI, 3D DESS//CISS/PSIF, GMR
IMAGING MODES
Single, multislice, volume study, multi angle, multi oblique
FOV
0.5 cm - 50 cm
Min 2D/3D: 0.1/0.05 mm
1024 x 1024 full screen display
MEASURING MATRIX
64 x 64 to 1024 x 1024
10 micrometer in plane
BORE DIAMETER
or W x H
60 cm
POWER REQUIREMENTS
380/400/420/440/480 V
STRENGTH
up to 45 mT/m
5-GAUSS FRINGE FIELD
2.5 m / 4.0 m
Passive, act.; 1st order std./2nd opt.
spacer

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

 
Further Reading:
  Basics:
12 510(k) MAGNETOM Avanto System(.pdf)
   by www.accessdata.fda.gov    
  News & More:
Obesity May Influence Imaging Diagnosis
Wednesday, 22 December 2004   by www.hospimedica.com    
Searchterm 'Magnet' was also found in the following services: 
spacer
News  (897)  Resources  (213)  Forum  (82)  
 
MAGNETOM Sonataâ„¢InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.med.siemens.com/med/d/gg/mr/products/sonata.html From Siemens Medical Systems;
while older navigator techniques take up to 40 minutes to create, the high performance of the MAGNETOM Sonata system enables 'complete examinations in less than 15 minutes'. It creates a new standard of diagnostic confidence and moves Cardiac MR from the research setting into routine clinical practice.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Compact
Yes/SVS or CSI opt.
SYNCHRONIZATION
ECG/peripheral, respiratory gating
PULSE SEQUENCES
GRE, IR, FIR, STIR, TrueIR/FISP, FSE, FLAIR, MT, SS-FSE, MT-SE, MTC, MSE, EPI, 3D DESS//CISS/PSIF, GMR
IMAGING MODES
Single, multislice, volume study, multi angle, multi oblique
TR
1.5 msec at 256matrix
TE
0.58 msec at 256matrix
SINGLE/MULTI SLICE
178 images/sec at 256 x 256 at 100% FOV
0.5 cm - 40 cm
Min 2D/3D: 0.1/0.05 mm
1024 x 1024 full screen display
MEASURING MATRIX
64 x 64 to 1024 x 1024
PIXEL INTENSITY
10 micrometer in plane
60 cm
MAGNET WEIGHT
4050kg, 5500kg in operation
H*W*D
236 x 215 x 160 cm
POWER REQUIREMENTS
380/400/420/440/480 V
COOLING SYSTEM TYPE
Single cryogen, 2 stage refrig.
Liquid He
STRENGTH
40/70 mT/m
5-GAUSS FRINGE FIELD
2.5 m / 4.0 m
Passive, act.; 1st order std./2nd opt.
spacer

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

Searchterm 'Magnet' was also found in the following services: 
spacer
Radiology  (44) Open this link in a new windowUltrasound  (33) Open this link in a new window
Superparamagnetism
 
Superparamagnetism occurs when the material is composed of very small crystallites (1-10 nm). In this case, even though the temperature is below the Curie or Néel temperature and the thermal energy is not sufficient to overcome the coupling forces between neighboring atoms, the thermal energy is sufficient to change the direction of magnetization of the entire crystallite. The resulting fluctuations in the direction of magnetization cause the magnetic field to average to zero. The material behaves in a manner similar to paramagnetism, except that instead of each individual atom being independently influenced by an external magnetic field, the magnetic moment of the entire crystallite tends to align with the magnetic field.
In MRI superparamagnetic iron oxide is used as a contrast agent.

See also magnetism, ferromagnetism, paramagnetism, and diamagnetism.
spacer

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

 
Further Reading:
  Basics:
Superparamagnetism
   by en.wikipedia.org    
  News & More:
Imagion (ASX:IBX) share price up 1,166% in a year pursuing adiation-freeâ„¢ cancer tech
Monday, 29 March 2021   by www.fool.com.au    
MRI Resources 
Contrast Enhanced MRI - Sequences - Open Directory Project - Implant and Prosthesis pool - Veterinary MRI - Online Books
 
previous      31 - 35 (of 612)     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 ?    



MRI is trending to low field magnets :
reduced costs will lead to this change 
AI will close the gap to high field 
only in remote areas 
is only temporary 
never 

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