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Result : Searchterm 'Shimming' found in 3 terms [] and 76 definitions []
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Searchterm 'Shimming' was also found in the following services: 
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News  (1)  Resources  (2)  Forum  (9)  
 
MAGNETOM Trio™ (TIM System)InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.
 
www.medical.siemens.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-11&catalogId=-11&catTree=100001%2C12786%2C12754&level=0&productId=145739 From Siemens Medical Systems;
The Magnetom Trio™, a 3T whole body MRI system with Tim (total imaging matrix technology), targets clinical applications such as abdominal, cardiac, spine, whole body and orthopedics. TIM enables flexible coil combinations for high resolution imaging of large anatomical areas without the need to change coils.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Short bore
CP head, CP integrated body coil, neck matrix, breast array, 8-channel knee array, CP wrist, shoulder array, CP extremity
Yes/Mutli-nuclear MRS
PULSE SEQUENCES
SE, IR, 2D/3D TurboSE, Turbo IR, Dark-Fluid IR, True IR, 2D/3D MEDIC, 2D/3D GRE FLASH, 2D/3D GRE FISP, 2D/3D PSIF, 2D TurboFLASH, 3D MP-RAGE, 3D TurboFLASH, 2D/3D TOF angiography, MTC, TONE with 3D TOF MRA, GMR, LOTA
IMAGING MODES
Single, multislice, volume study, multi angle, multi oblique
SINGLE/MULTI SLICE
178 images/sec at 256 x 256 at 100% FOV
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
10 micrometer
60 cm
MAGNET WEIGHT
12000 kg
H*W*D
221 x 244 x 213 cm
POWER REQUIREMENTS
380/400/420/440/480 V
COOLING SYSTEM TYPE
Single cryogen, 2 stage refrig.
0.12 L/hr helium
STRENGTH
40 - 45 mT/m
200 mT/m/ms
5-GAUSS FRINGE FIELD
3.4 m / 5.9 m
Passive, act.; 1st order std./2nd opt.
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MRI Resources 
Intraoperative MRI - Manufacturers - Jobs pool - Most Wanted - Pathology - Implant and Prosthesis pool
 
MAGNETOM Verio
 
www.healthcare.siemens.com/magnetic-resonance-imaging/3t-mri-scanner/magnetom-verio From Siemens Medical Systems;
Received FDA clearance in 2007.
The MAGNETOM Verio provides up to 102 integrated matrix coil elements and up to 32 independent radiofrequency channels that allow flexible coil combinations to make patient and coil repositioning virtually unnecessary. The Tim (total imaging matrix) technology also increases patient throughput due to a shorter scan time.
The open bore design offers great comfort for patients of all shapes and sizes.
Device Information and Specification
CLINICAL APPLICATION
Whole Body
CONFIGURATION
Ultra-short open bore
3 Tesla
Head, spine, torso/ body coil, neurovascular, cardiac, neck and multi-purpose flex coils. Peripheral vascular, breast, shoulder, knee, wrist, foot//ankle, TMJ optional.
CHANNELS (min. / max. configuration)
8, 18, 32
Chemical shift imaging, single voxel spectroscopy
IMAGING TECHNIQUES
iPAT, mSENSE and GRAPPA (image, k-space), noncontrast angiography, radial motion compensation, Dixon
MINIMUM TR
3-D GRE: 1.5 (256 matrix)
MINIMUM TE
3-D GRE: 0.63 (256 matrix)
FOV
0.5 - 50 cm
BORE DIAMETER
or W x H
At isocenter: L-R 70 cm, A-P 55 cm
TABLE CAPACITY
250 kg
MAGNET WEIGHT (gantry included)
8200 kg
DIMENSION H*W*D (gantry included)
173 x 230 x 222 cm
5-GAUSS FRINGE FIELD
2.6 m / 4.6 m
CRYOGEN USE
Zero boil off rate, refill approx. 10 years
COOLING SYSTEM
Water
up to 200 T/m/s
MAX. AMPLITUDE
45 mT/m
Passive, active; first order, second order standard
POWER REQUIREMENTS
380 / 400 / 420 / 440 / 460 / 480 V, 3-phase + ground; 110 kVA
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MRI Resources 
Homepages - Brain MRI - Stent - Non-English - Cochlear Implant - Breast Implant
 
MAGNETOM™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.medical.siemens.com From Siemens Medical Systems;
70 cm + 125 cm + 1.5T and Tim - a combination never seen before in MRI ... MAGNETOM Espree™s unique open bore design can accommodate more types of patients than other 1.5T systems on the market today, in particular the growing population of obese patients. The power of 1.5T combined with Tim technology boosts signal to noise, which is necessary to adequately image obese patients.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Open bore
Body, Tim [32 x 8], Tim [76 coil elements with up to 18 RF channels])
SYNCHRONIZATION
ECG/peripheral: Optional/yes, 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
SINGLE/MULTI SLICE
Image Processor reconstructing up to 3226 images per second (256 x 256, 25% recFoV)
FOV
35 cm coronal//sagittal, 45 cm axial
Min 2D/3D: 0.1/0.05 mm
1024 x 1024 full screen display
MEASURING MATRIX
64 x 64 to 1024 x 1024
BORE DIAMETER
or W x H
70 cm diameter
MAGNET WEIGHT
3800 kg
H*W*D
? x ? x 125 cm
STRENGTH
33 mT/m
5-GAUSS FRINGE FIELD
2.5 m / 3.8 m
Passive, active
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• View the DATABASE results for 'MAGNETOM Espree™' (2).Open this link in a new window

 
Further Reading:
  News & More:
First 1.5 Tesla Open Bore MRI Introduced
Tuesday, 10 August 2004   by www.hospimedica.com    
Obesity May Influence Imaging Diagnosis
Wednesday, 22 December 2004   by www.hospimedica.com    
Searchterm 'Shimming' was also found in the following services: 
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News  (1)  Resources  (2)  Forum  (9)  
 
MSK-Extreme™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.onicorp.com/ From ONI Medical Systems, Inc.;
MSK-Extreme™MRI system is a dedicated high field extremity imaging device, designed to provide orthopedic surgeons and other physicians with detailed diagnostic images of the foot, ankle, knee, hand, wrist and elbow, all with the clinical confidence and advantages derived from high field, whole body MRI units. The light weight (less than 650 kg) of the OrthOne System performs rapid patient studies, is easy to operate, has a patient friendly open environment and can be installed in a practice office or hospital, all at a cost similar to a low field extremity machine.
New features include a more powerful operating system that offers increased scan speed as well as a 160-mm knee coil with higher signal to noise ratio, and the option of a CD burner.
Device Information and Specification
CLINICAL APPLICATION
Dedicated extremity imaging
CONFIGURATION
16 cm knee, 18 cm lower extremity;; 12.3 cm upper extremity, additional high resolution v-SPEC Coils: 80 mm, 100 mm, or 145 mm.
SYNCHRONIZATION
No
PULSE SEQUENCES
SE, FSE, GE2D, GE3D, Inversion recovery (IR), Driven Equilibrium, Fat Saturation (FS), STIR, MT, PD, Flow Compensation (FC), RF spoiling, MTE, No Phase Wrap (NPW)
IMAGING MODES
Scout, single, multislice, volume
TR
10-10,000ms; 1ms steps
TE
5-150ms; 1 ms steps
SINGLE/MULTI SLICE
2D less than 200 msec/image
4cm-16cm
2D: 2mm-10mm/.1mm incr.
Up to 1,000x1,000
MEASURING MATRIX
X/Y: 64-512; 2 pixel steps
PIXEL INTENSITY
4,096 grey lvls; 256 lvls in 3D
28cm ID x 50cm L
MAGNET WEIGHT
635 kg
H*W*D
146 x 69 x 84 cm
POWER REQUIREMENTS
115VAC, 1phase, 20A; 208VAC, 3 phase, 30A
COOLING SYSTEM TYPE
LHe with 2 stage cold head
Negligible
STRENGTH
15 mT/m
5-GAUSS FRINGE FIELD
1.25m radial x 1.8m axial
Passive
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Further Reading:
  Basics:
MSK Extreme Brochure(.pdf)
   by www.nova-logic.ch    
MSK Extreme Specifications(.pdf)
   by www.nova-logic.ch    
MRI Resources 
Lung Imaging - Portals - Manufacturers - Pregnancy - Used and Refurbished MRI Equipment - Intraoperative MRI
 
Magnetic Resonance SpectroscopyMRI Resource Directory:
 - Spectroscopy pool -
 
(MRS / MRSI - Magnetic Resonance Spectroscopic Imaging) A method using the NMR phenomenon to identify the chemical state of various elements without destroying the sample. MRS therefore provides information about the chemical composition of the tissues and the changes in chemical composition, which may occur with disease processes.
Although MRS is primarily employed as a research tool and has yet to achieve widespread acceptance in routine clinical practice, there is a growing realization that a noninvasive technique, which monitors disease biochemistry can provide important new information for the clinician.
The underlying principle of MRS is that atomic nuclei are surrounded by a cloud of electrons, which very slightly shield the nucleus from any external magnetic field. As the structure of the electron cloud is specific to an individual molecule or compound, then the magnitude of this screening effect is also a characteristic of the chemical environment of individual nuclei.
In view of the fact that the resonant frequency is proportional to the magnetic field that it experiences, it follows that the resonant frequency will be determined not only by the external applied field, but also by the small field shift generated by the electron cloud. This shift in frequency is called the chemical shift (see also Chemical Shift). It should be noted that chemical shift is a very small effect, usually expressed in ppm of the main frequency. In order to resolve the different chemical species, it is therefore necessary to achieve very high levels of homogeneity of the main magnetic field B0. Spectra from humans usually require shimming the magnet to approximately one part in 100. High resolution spectra of liquid samples demand a homogeneity of about one part in 1000.
In addition to the effects of factors such as relaxation times that can affect the NMR signal, as seen in magnetic resonance imaging, effects such as J-modulation or the transfer of magnetization after selective excitation of particular spectral lines can affect the relative strengths of spectral lines.
In the context of human MRS, two nuclei are of particular interest - H-1 and P-31. (PMRS - Proton Magnetic Resonance Spectroscopy) PMRS is mainly employed in studies of the brain where prominent peaks arise from NAA, choline containing compounds, creatine and creatine phosphate, myo-inositol and, if present, lactate; phosphorus 31 MR spectroscopy detects compounds involved in energy metabolism (creatine phosphate, adenosine triphosphate and inorganic phosphate) and certain compounds related to membrane synthesis and degradation. The frequencies of certain lines may also be affected by factors such as the local pH. It is also possible to determine intracellular pH because the inorganic phosphate peak position is pH sensitive.
If the field is uniform over the volume of the sample, "similar" nuclei will contribute a particular frequency component to the detected response signal irrespective of their individual positions in the sample. Since nuclei of different elements resonate at different frequencies, each element in the sample contributes a different frequency component. A chemical analysis can then be conducted by analyzing the MR response signal into its frequency components.

See also Spectroscopy.
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• View the DATABASE results for 'Magnetic Resonance Spectroscopy' (8).Open this link in a new window


• View the NEWS results for 'Magnetic Resonance Spectroscopy' (3).Open this link in a new window.
 
Further Reading:
  News & More:
Accuracy of Proton Magnetic Resonance Spectroscopy in Distinguishing Neoplastic From Non-neoplastic Brain Lesions
Saturday, 2 December 2023   by www.cureus.com    
MRI Resources 
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