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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)  
 
Balanced Fast Field EchoInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
(bFFE) A FFE sequence using a balanced gradient waveform. A balanced sequence starts out with a RF pulse of 90° or less and the spins in the steady state. Before the next TR in the slice phase and frequency encoding, gradients are balanced so their net value is zero. Now the spins are prepared to accept the next RF pulse, and their corresponding signal can become part of the new transverse magnetization. Since the balanced gradients maintain the transverse and longitudinal magnetization, the result is, that both T1 and T2 contrast are represented in the image. This pulse sequence produces images with increased signal from fluid, along with retaining T1 weighted tissue contrast. Because this form of sequence is extremely dependent on field homogeneity, it is essential to run a shimming prior the acquisition. A fully balanced (refocused) sequence would yield higher signal, especially for tissues with long T2 relaxation times.

See Steady State Free Precession and Gradient Echo Sequence.
 
Images, Movies, Sliders:
 Cardiac Infarct Short Axis Cine bFFE 1  Open this link in a new window
    
 
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Further Reading:
  News & More:
T1rho-prepared balanced gradient echo for rapid 3D T1rho MRI
Monday, 1 September 2008   by www.ncbi.nlm.nih.gov    
Utility of the FIESTA Pulse Sequence in Body Oncologic Imaging: Review
June 2009   by www.ajronline.org    
MRI Resources 
Crystallography - Education pool - Nerve Stimulator - Abdominal Imaging - Distributors - Implant and Prosthesis
 
Balanced SequenceForum -
related threadsInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
This family of sequences uses a balanced gradient waveform. This waveform will act on any stationary spin on resonance between 2 consecutive RF pulses and return it to the same phase it had before the gradients were applied. A balanced sequence starts out with a RF pulse of 90° or less and the spins in the steady state. Prior to the next TR in the slice encoding, the phase encoding and the frequency encoding direction, gradients are balanced so their net value is zero. Now the spins are prepared to accept the next RF pulse, and their corresponding signal can become part of the new transverse magnetization. If the balanced gradients maintain the longitudinal and transverse magnetization, the result is that both T1 and T2 contrast are represented in the image.
This pulse sequence produces images with increased signal from fluid (like T2 weighted sequences), along with retaining T1 weighted tissue contrast. Balanced sequences are particularly useful in cardiac MRI. Because this form of sequence is extremely dependent on field homogeneity, it is essential to run a shimming prior the acquisition.
Usually the gray and white matter contrast is poor, making this type of sequence unsuited for brain MRI. Modifications like ramping up and down the flip angles can increase signal to noise ratio and contrast of brain tissues (suggested under the name COSMIC - Coherent Oscillatory State acquisition for the Manipulation of Image Contrast).
These sequences include e.g. Balanced Fast Field Echo (bFFE), Balanced Turbo Field Echo (bTFE), Fast Imaging with Steady Precession (TrueFISP, sometimes short TRUFI), Completely Balanced Steady State (CBASS) and Balanced SARGE (BASG).
 
Images, Movies, Sliders:
 Cardiac Infarct Short Axis Cine Overview  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 Infarct 4 Chamber Cine  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 
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• View the DATABASE results for 'Balanced Sequence' (5).Open this link in a new window

 
Further Reading:
  News & More:
Generic Eddy Current Compensation for Rapid Magnetic Resonance Imaging(.pdf)
   by www.switt.ch    
Magnetic resonance imaging guided musculoskeletal interventions at 0.23T: Chapter 4. Materials and methods
2002
MRI Resources 
Cardiovascular Imaging - Chemistry - Databases - - Shoulder MRI - Pacemaker
 
Bilateral Breast Imaging in the Sagittal View with SENSEInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(BLISS) BLISS is a magnetic resonance imaging technique that provides the measurement of two bilateral volumes in a single acquisition. Localized shimming for each volume improves the fat suppression. BLISS is an imaging sequence for sagittal breast MRI studies with high spatial resolution and short scan time.
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Searchterm 'Shimming' was also found in the following services: 
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News  (1)  Resources  (2)  Forum  (9)  
 
Biograph mMR
 
www.healthcare.siemens.com/magnetic-resonance-imaging/mr-pet-scanner/biograph-mmr FDA cleared and CE Mark 2011.
The Biograph mMR has a fully-integrated design for simultaneous PET/MRI imaging. The dedicated hardware includes solid-state, avalanche photodiode PET detector and adapted, PET-compatible MR coils.
The possibility of truly simultaneous operation allows the acquisition of several magnetic resonance imaging (MRI) sequences during the positron emission tomography (PET) scan, without increasing the examination time.
See also Hybrid Imaging.
Device Information and Specification
CLINICAL APPLICATION
Whole Body
CONFIGURATION
Simultaneous PET/MRI
3 Tesla
Full range of MRI coils
CHANNELS
up to 32
PET ACQUISITION MODES
3D
MRI ACQUISITION MODES
2D/3D, spectroscopy;; iPAT, GRAPPA (k-space), noncontrast angiography, radial motion compensation
PET EFFECTIVE AXIAL FOV
26 cm (typical overlap 23%)
MRI FOV
A-P 45, R-L 50, H-F 50 cm
PET RING DIAMETER
65.6 cm
PATIENT SCAN RANGE
199 cm
HORIZONTAL SPEED
200 mmsec
TABLE CAPACITY
200 kg
PET DETECTOR
Solid state, 4032 avalanche photo diodes
DETECTOR SCINTILLATION MATERIAL
LSO, 28672 crystals
CRYSTAL SIZE
4 x 4 x 20 mm
MAGNET WEIGHT
9000 kg
DIMENSION H*W*D (gantry included)
335 x 230 x 242 cm (finshed covers)
5-GAUSS FRINGE FIELD
2.6 m / 4.6 m
CRYOGEN USE
Zero boil off rate, approx. 10 years
COOLING SYSTEM
PET system: water; MRI system: water
up to 200 T/m/s
MAX. AMPLITUDE
45 mT/m
Aautomatic, patient specific shim; active shim 3 linear and 5 non-linear channels (seond order)
POWER REQUIREMENTS
380 / 400 / 420 / 440 / 460 / 480 V, 3-phase + ground; Total system 110kW
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Further Reading:
  Basics:
Performance Measurements of the Siemens mMR Integrated Whole-Body PET/MR Scanner
Friday, 11 November 2011   by jnm.snmjournals.org    
Global Trends in Hybrid Imaging
Monday, 1 November 2010   by pubs.rsna.org    
  News & More:
Positron Emission Tomographic Imaging in Stroke
Monday, 28 December 2015   by www.ncbi.nlm.nih.gov    
A world's first in imaging – integrated whole-body molecular MR system available for clinical use testing
Thursday, 18 November 2010   by www.siemens.com    
FDA Clears New System to Perform Simultaneous PET, MRI Scans
Friday, 10 June 2011   by www.prnewswire.com    
Frost & Sullivan Award Underlines Siemens Healthcare's Contribution to New Product Innovation in the North American Medical Imaging Market
Wednesday, 13 July 2011   by multivu.prnewswire.com    
MRI Resources 
Abdominal Imaging - Education - Education pool - MRI Technician and Technologist Schools - Diffusion Weighted Imaging - IR
 
C-SCAN™InfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
www.gehealthcare.com/usen/mr/cscan/index.html Manufactured by Esaote S.p.A.; compact in-office MRI system, fits in a 90 ft2 (8.4 m2) space and requires no shielding or special power. This low field MRI magnet is optimized for orthopedic use and imaging of the extremities.
The C-SCAN™ is developed from the ARTOSCAN™ - M with a new computer platform, and is also known as Artoscan C.
Esaote North America and Hologic Inc. are the U.S. distributors of this MRI device.
Device Information and Specification
CLINICAL APPLICATION
Dedicated extremity
CONFIGURATION
Closed
Linear and dual phased array, knee, ankle, wrist (6 total) coils
PULSE SEQUENCES
SE, GE, IR, STIR, FSE, 3D CE, GE-STIR, 3D GE, ME, TME, HSE
IMAGING MODES
Single, multislice, volume study, fast scan, multi slab
TR
12 - 5,000 msec
TE
5 - 220 msec
SINGLE SLICE
0.8 sec/image
MULTISLICE
0.8 sec/image
FOV
10 - 20 cm
2D: 2 mm - 10 mm;
3D: 0.6 mm - 10 mm
512 x 512
MEASURING MATRIX
256 x 256 maximum
PIXEL INTENSITY
4,096 gray lvls, 256 lvls in 3D
MAGNET TYPE
Permanent
BORE DIAMETER
or W x H
33.6 x 16 cm
MAGNET WEIGHT
960 kg
H*W*D
124 x 76 x 60 cm
POWER REQUIREMENTS
100/110/200/220/230/240
STRENGTH
10 mT/m
5-GAUSS FRINGE FIELD, radial/axial
28 cm/60 cm
Passive
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• View the DATABASE results for 'C-SCAN™' (4).Open this link in a new window

MRI Resources 
Safety Training - RIS - MR Myelography - Education - Cochlear Implant - Spectroscopy pool
 
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