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

Out-
      side
 



 
 'Noise' 
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 'Noise' found in 12 terms [] and 72 definitions []
previous     16 - 20 (of 84)     next
Result Pages : [1 2 3]  [4 5 6 7 8 9 10 11 12 13 14 15 16 17]
Searchterm 'Noise' was also found in the following services: 
spacer
News  (14)  Forum  (13)  
 
MR Compatibility
 
mri safety guidance
MRI Safety Guidance
If a device is to be labeled MR Safe, the following information should be provided:
•
Data demonstrating that when the device is introduced or used in the MRI environment (i.e. the MRI scan room) it does not pose an increased safety risk to the patient or other personnel,
•
a scientifically-based rationale for why data are not necessary to prove the safety of the device in the MR environment (for example, a passive device made entirely of a polymer known to be nonreactive in strong magnetic fields).

If a device is to be labeled MR Compatible, the following information should be provided:
•
Data demonstrating that when the device is introduced or used in the MRI environment, it is MR safe that it performs its intended function without performance degradation, and that it does not adversely affect the function of the MRI scanner (e.g. no significant image artifacts or noise). Any image artifact or noise due to the medical device should be quantified (e.g., % volume affected, signal to noise ratio),
•
a scientifically-based rationale for why data are not necessary to prove the compatibility of the device in the MRI environment.

Test Conditions:
The static magnetic field strength (Gauss (G) or Tesla (T)) to which the device was tested and demonstrated to be MRI 'safe', 'compatible', or 'intended for use in' should be related to typical machine ratings (e.g. 0.5 T, 1.5 T, 2.0 T, and shielded or unshielded magnet, etc).
The same conditions should be used for the spatial gradient (field strength per unit distance (i.e., G/cm)) in which the device was tested and demonstrated to be 'safe', 'compatible', or 'intended for use in'.
Also the RF transmitter power used during testing of the device, should be related to this typical machine ratings.
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.


• View the NEWS results for 'MR Compatibility' (2).Open this link in a new window.
 
Further Reading:
  Basics:
Newer Heart Devices Safe During MRI
Monday, 23 August 2004   by www.hospimedica.com    
  News & More:
Boston Scientific and Biophan in MRI Collaboration
Friday, 21 November 2003   by www.medimaging.net    
MRI safety targeted as new group offers credentialing test
Monday, 12 January 2015   by www.modernhealthcare.com    
FDA Releases New Guidance On Establishing Safety, Compatibility Of Passive Implants In MR Environments
Tuesday, 16 December 2014   by www.meddeviceonline.com    
Searchterm 'Noise' was also found in the following services: 
spacer
Radiology  (15) Open this link in a new windowUltrasound  (15) Open this link in a new window
Excelart AG™ with PianissimoInfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
http://www.medical.toshiba.com/clinical/radiology/15texcelart.htm From Toshiba America Medical Systems Inc.;
the EXCELART is a superconducting whole body MRI system with a short wide-bore magnet, operating at 1.5 T. It features powerful high-speed gradients with a revolutionary gradient acoustic noise reduction system: Pianissimo. The dramatic reduction of gradient acoustic noise by Pianissimo greatly enhances patient comfort during exams. The standard array platform and a wide range of array coils ensure excellent images. A powerful 64-bit RISC-based computer system and newly developed array processor realize high productivity.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Cylindrical Wide Short Bore
Opt. (WIP) Single and Multi Voxel
SYNCHRONIZATION
ECG: standard; peripheral: optional, respiratory gating
PULSE SEQUENCES
SE, FE, IR, FastSE, FastIR, FastFLAIR, Fast STIR, FastFE, FASE, Hybrid EPI, Multi Shot EPI; Angiography: 2D(gate/non-gate)/3D TOF, SORS-STC
IMAGING MODES
Single, multislice, volume study
TR
3.5-30000 msec
TE
8 msec min. SE; 1.2 msec min. FE
SINGLE/MULTI SLICE
less than 0.015 (256x256)
FOV
2 cm
1.0 min. 2-DFT: 0.2 min. 3-DFT
Up to 1024
MEASURING MATRIX
32-1024, phase;; 64-1024, freq.
PIXEL INTENSITY
256 gray levels
BORE DIAMETER
or W x H
65.5 cm, patient aperture
MAGNET WEIGHT
4050 kg (bare magnet incl. L-He)
H*W*D
235 x 219 x 199 cm
COOLING SYSTEM TYPE
Closed-loop water-cooled
CRYOGEN USE
Liquid helium: approx. less than 0.05 L/hr
STRENGTH
25 mT/m
5-GAUSS FRINGE FIELD
2.5 m / 4.0 m
Passive, active, auto-active
spacer

• View the DATABASE results for 'Excelart AG™ with Pianissimo' (2).Open this link in a new window

MRI Safety Resources 
Implant and Prosthesis pool - Safety Products - Safety Training - Stimulator pool - Shielding
 
Excelart XG™ with PianissimoInfoSheet: - Devices -
Intro, 
Types of Magnets, 
Overview, 
etc.MRI Resource Directory:
 - Devices -
 
http://www.medical.toshiba.com/clinical/radiology/15texcelart.htm From Toshiba America Medical Systems Inc.;
the EXCELART is a superconducting whole body MRI system with a short wide-bore magnet, operating at 1.5 T. It features powerful high-speed gradients with a revolutionary gradient acoustic noise reduction system: Pianissimo. The dramatic reduction of gradient acoustic noise by Pianissimo greatly enhances patient comfort during exams. The standard array platform and a wide range of array coils ensure excellent images. A powerful 64-bit RISC-based computer system and newly developed array processor realize high productivity.
Device Information and Specification
CLINICAL APPLICATION
Whole body
CONFIGURATION
Cylindrical Wide Short Bore
Optional (WIP)
SYNCHRONIZATION
ECG/peripheral, respiratory gating
PULSE SEQUENCES
SE, FE, IR, FastSE, FastIR, FastFLAIR, Fast STIR, FastFE, FASE, Hybrid EPI, Multi Shot EPI; Angiography: 2D(gate/non-gate)/3D TOF, SORS-STC
IMAGING MODES
Single, multislice, volume study
TR
2.6-30000 msec
TE
8 msec min. SE; 0.9 msec min. FE
SINGLE/MULTI SLICE
less than 0.011 (256x256)
FOV
2 cm
1.0 min. 2-DFT: 0.2 min. 3-DFT
Up to 1024
MEASURING MATRIX
32-1024, phase;; 64-1024, freq.
PIXEL INTENSITY
256 gray levels
BORE DIAMETER
or W x H
65.5 cm, patient aperture
MAGNET WEIGHT
4050 kg (bare magnet incl. L-He)
H*W*D
235 x 219 x 199 cm
POWER REQUIREMENTS
380/400/415/440/480 V
COOLING SYSTEM TYPE
Closed-loop water-cooled
CRYOGEN USE
Liquid helium: approx. less than 0.05 L/hr
STRENGTH
25 mT/m
5-GAUSS FRINGE FIELD
2.5 m / 4.0 m
Passive, active, auto-active
spacer

• View the DATABASE results for 'Excelart XG™ with Pianissimo' (2).Open this link in a new window

 
Further Reading:
  News & More:
Angio, cardiac imaging top list for MR and CT
1999   by www.diagnosticimaging.com    
Searchterm 'Noise' was also found in the following services: 
spacer
News  (14)  Forum  (13)  
 
Half Scan
 
(HS) A method in which approximately one half of the acquisition matrix in the phase encoding direction is acquired. Half scan is possible because of symmetry in acquired data. Since negative values of phase encoded measurements are identical to corresponding positive values, only a little over half (more than 62.5%) of a scan actually needs to be acquired to replicate an entire scan. This results in a reduction in scan time at the expense of signal to noise ratio. The time reduction can be nearly a factor of two, but full resolution is maintained.
Half scan can be used when scan times are long, the signal to noise ratio is not critical and where full spatial resolution is required. Half scan is particularly appropriate for scans with a large field of view and relatively thick slices; and, in 3D scans with many slices. In some fast scanning techniques the use of Half scan enables a shorter TE thus improving contrast. For this reason, the Half scan parameter is located in the contrast menu.

More information about scan time reduction; see also partial fourier technique.
spacer

• View the DATABASE results for 'Half Scan' (4).Open this link in a new window

Searchterm 'Noise' was also found in the following services: 
spacer
Radiology  (15) Open this link in a new windowUltrasound  (15) Open this link in a new window
Lung ImagingMRI Resource Directory:
 - Lung Imaging -
 
Lung imaging is furthermore a challenge in MRI because of the predominance of air within the lungs and associated susceptibility issues as well as low signal to noise of the inflated lung parenchyma. Cardiac and respiratory triggered or breath hold sequences allow diagnostic imaging, however a comparable image quality with computed tomography is still difficult to achieve.
Assumptions for lung MRI:
•
Low signal to noise ratio of the inherently low lung proton density.
•
Cardiac and respiratory motion artifacts.
•
Magnetic susceptibility effects of large magnetic field gradients.
•
Very short transverse relaxation times and significant diffusion yielding short T2 (30-70 msec), short T2* (1-3 msec), and additional long T1 relaxation times (1300-1500 msec).
•
The extreme short T2 values are responsible for a fast signal decay during a single shot readout, resulting in blurring.

The current trends in MRI are the use of new imaging technologies and increasingly powerful magnetic fields. Among these technologies are parallel imaging techniques as well as ventilation agents like hyperpolarized helium for the use as an inert inhalational contrast agent to study lung ventilation properties. With hyperpolarized gases clear images of the lungs can be obtained without using a large magnetic field (see also back projection imaging). Single shot sequences (e.g. TSE or Half Fourier Acquisition Single Shot Turbo Spin Echo HASTE) used in lung MR imaging benefits from parallel imaging techniques due to reduced relaxation time effects during the echo train and therefore reduced image blurring as well as reduced motion artifacts.
In the future, more effective contrast agents may provide an alternative solution to the need for high field MRI. Dynamic contrast enhanced MRI perfusion has demonstrated a potential in the diagnosis of pulmonary embolism or to characterize lung cancer and mediastinal tumors. 3D contrast enhanced magnetic resonance angiography of the thoracic vessel.

See also the related poll result: 'MRI will have replaced 50% of x-ray exams by'
 
Images, Movies, Sliders:
 Anatomic Imaging of the Lungs  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 Normal Lung Gd Perfusion MRI  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 MRI Thorax Basal Plane  Open this link in a new window
 
Radiology-tip.comradLung Scintigraphy
spacer

• View the DATABASE results for 'Lung Imaging' (7).Open this link in a new window


• View the NEWS results for 'Lung Imaging' (3).Open this link in a new window.
 
Further Reading:
  Basics:
A safer approach for diagnostic medical imaging
Monday, 29 September 2014   by www.eurekalert.org    
Parallel Lung Imaging(.pdf)
  News & More:
Chest MRI a viable alternative to chest CT in COVID-19 pneumonia follow-up
Monday, 21 September 2020   by www.healthimaging.com    
CT Imaging Features of 2019 Novel Corona virus (2019-nCoV)
Tuesday, 4 February 2020   by pubs.rsna.org    
Polarean Imaging Phase III Trial Results Point to Potential Improvements in Lung Imaging
Wednesday, 29 January 2020   by www.diagnosticimaging.com    
Low Power MRI Helps Image Lungs, Brings Costs Down
Thursday, 10 October 2019   by www.medgadget.com    
Chest MRI Using Multivane-XD, a Novel T2-Weighted Free Breathing MR Sequence
Thursday, 11 July 2019   by www.sciencedirect.co    
Researchers Review Importance of Non-Invasive Imaging in Diagnosis and Management of PAH
Wednesday, 11 March 2015   by lungdiseasenews.com    
New MRI Approach Reveals Bronchiectasis' Key Features Within the Lung
Thursday, 13 November 2014   by lungdiseasenews.com    
MRI techniques improve pulmonary embolism detection
Monday, 19 March 2012   by medicalxpress.com    
  News & More:
Partnership with VIDA to streamline adoption of advanced MRI of the lungs
Monday, 11 September 2023   by www.itnonline.com    
MRI Resources 
Pathology - Breast MRI - Spectroscopy pool - Pediatric and Fetal MRI - Directories - Coils
 
previous      16 - 20 (of 84)     next
Result Pages : [1 2 3]  [4 5 6 7 8 9 10 11 12 13 14 15 16 17]
 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. [ 23 November 2024]
Terms of Use | Privacy Policy | Advertising
 [last update: 2024-02-26 03:41:00]