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Result : Searchterm 'SAR' found in 3 terms [] and 60 definitions []
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Searchterm 'SAR' was also found in the following services: 
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News  (34)  Resources  (14)  Forum  (22)  
 
Prosthetic Heart ValvesMRI Resource Directory:
 - Safety -
 
The interactions between the most tested heart valve prostheses and the magnetic field of MRI devices are of no significance. However, there are many different types of heart valve prostheses and in the particular case their MRI safety should be checked.
mri safety guidance
MRI Safety Guidance
Prosthetic heart valves, depending on the type and the material, are not necessarily considered to be dangerous in fields up to 3T. Patients should not undergo high field MRI examinations if valve dehiscence is clinically suspected.
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• For this and other aspects of MRI safety see our InfoSheet about MRI Safety.
• Patient-related information is collected in our MRI Patient Information.

 
• Related Searches:
    • Cardiac Risks
    • Cardiac Pacemaker
    • Cardiac MRI
    • Specific Absorption Rate
    • High Field MRI
 
Further Reading:
  Basics:
Prosthetic Heart Valves: Evaluation of Magnetic Field Interactions, Heating, and Artifacts at 1.5 T
2000   by www.imrser.org    
  News & More:
Guidelines for the Management of Patients with Heart Valve Prostheses and Annuloplasty Rings Referred for MRI Procedures
Tuesday, 1 January 2019   by www.ismrm.org    
Codman Neuro develops new MRI-resistant programmable valve for treatment of hydrocephalus
Tuesday, 22 September 2015   by www.news-medical.net    
MRI Safety Resources 
Safety Products - Nerve Stimulator - Safety Training - Pacemaker - Implant and Prosthesis pool
 
Radio Frequency CoilInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
A coil is a large inductor with a considerable dimension and a defined wavelength, commonly used in configurations for MR imaging. The frequency of the radio frequency coil is defined by the Larmor relationship.
The MRI image quality depends on the signal to noise ratio (SNR) of the acquired signal from the patient. Several MR imaging coils are necessary to handle the diversity of applications. Large coils have a large measurement field, but low signal intensity and vice versa (see also coil diameter). The closer the coil to the object, the stronger the signal - the smaller the volume, the higher the SNR. SNR is very important in obtaining clear images of the human body. The shape of the coil depends on the image sampling. The best available homogeneity can be reached by choice of the appropriate coil type and correct coil positioning. Orientation is critical to the sensitivity of the RF coil and therefore the coil should be perpendicular to the static magnetic field.

RF coils can be differentiated by there function into three general categories:
The RF signal is in the range of 10 to 100 MHz. During a typical set of clinical image measurements, the entire frequency spectrum of interest is of the order 10 kHz, which is an extremely narrow band, considering that the center frequency is about 100 MHz. This allows the use of single-frequency matching techniques for coils because their inherent bandwidth always exceeds the image bandwidth. The multi turn solenoid, bird cage coil, single turn solenoid, and saddle coil are typically operated as the transmitter and receiver of RF energy. The surface and phased array coils are typically operated as a receive only coil.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'
 
Images, Movies, Sliders:
 Circle of Willis, Time of Flight, MIP  Open this link in a new window
    
SlidersSliders Overview

 Anatomic MRI of the Knee 1  Open this link in a new window
    
SlidersSliders Overview

 
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• View the DATABASE results for 'Radio Frequency Coil' (9).Open this link in a new window

 
Further Reading:
  Basics:
Radio-frequency Coil Selection for MR Imaging of the Brain and Skull Base1
   by radiology.rsnajnls.org    
  News & More:
High-field MRI Coils – that work, superbly, even at 750 MHz
   by www.dotynmr.com    
Magnetic resonance-guided motorized transcranial ultrasound system for blood-brain barrier permeabilization along arbitrary trajectories in rodents
Thursday, 24 December 2015   by www.ncbi.nlm.nih.gov    
MRI Resources 
Pathology - Hospitals - Chemistry - MRI Training Courses - Mobile MRI Rental - Equipment
 
Radio Frequency Spoiled Steady State Acquisition Rewound Gradient EchoInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
(RSSARGE) A sequence with spoiled gradient echoes.
See Spoiled Gradient Echo Sequence.
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• View the DATABASE results for 'Radio Frequency Spoiled Steady State Acquisition Rewound Gradient Echo' (2).Open this link in a new window

Searchterm 'SAR' was also found in the following services: 
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News  (34)  Resources  (14)  Forum  (22)  
 
Resovist®InfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
Resovist® is an organ-specific MRI contrast agent, used for the detection and characterization of especially small focal liver lesions.
Resovist® consists of superparamagnetic iron oxide (SPIO) nanoparticles coated with carboxydextran, which are accumulated by phagocytosis in cells of the reticuloendothelial system (RES) of the liver. The uptake of Resovist® Injection in the reticuloendothelial cells results in a decrease of the signal intensity of normal liver parenchyma on both T2- and T1 weighted images.
Most malignant liver tumors do not contain RES cells and therefore do not uptake the iron particles. The resulting imaging effect is an improved contrast between the tumor (bright) and the surrounding tissue (dark).
Resovist® can be injected as an intravenous bolus, which allows immediate imaging of the liver and reduces the overall examination time. A dynamic imaging strategy after bolus injection supports to characterize lesions. In comprehensive clinical trials, it demonstrated an excellent safety profile.
In 2001, Resovist® was approved for the European market.

See also Superparamagnetic Iron Oxide.

Resovist® competed with Primovist™, the other liver imaging agent of Bayer Schering Pharma AG. Due to this reason, the production of Resovist® has been abandoned in 2009.
Drug Information and Specification
NAME OF COMPOUND
Ferrixan [Ferucarbotran], carboxydextran coated iron oxide nanoparticles
CENTRAL MOIETY
Fe2+
CONTRAST EFFECT
T2/T1, Predominantly negative enhancement
r1=25.4, r2=151,
PHARMACOKINETIC
RES-directed
333 mosm/kg
CONCENTRATION
0.5 mol Fe/L
DOSAGE
Less than 60 kg = 0.9 ml, greater than 60 kg = 1.4 ml
PREPARATION
Finished product
INDICATION
Liver lesions
DISTRIBUTOR
See below
PRESENTATION
Pre-filled syringes of 0.9 and 1.4 mL
DO NOT RELY ON THE INFORMATION PROVIDED HERE, THEY ARE
NOT A SUBSTITUTE FOR THE ACCOMPANYING PACKAGE INSERT!
Distribution Information
TERRITORY
TRADE NAME
DEVELOPMENT
STAGE
DISTRIBUTOR
USA
Resovist®
?
-
Japan
Resovist®
approved
-
EU
Resovist®
approved
-
Australia
Resovist®
Approved
-
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• View the DATABASE results for 'Resovist®' (6).Open this link in a new window

 
Further Reading:
  News & More:
Optimized Labelling of Human Monocytes with Iron Oxide MR Contrast Agents
Sunday, 30 November 2003   by rsna2003.rsna.org    
MRI Resources 
Online Books - Process Analysis - MRI Training Courses - Pacemaker - Mobile MRI Rental - Blood Flow Imaging
 
Sensitive Point
 
The sensitive point in an object (or a region) is the point from which information is being measured, as in sequential point imaging or in single voxel MR spectroscopy sequential point imaging used. To define a sensitive point, it must be selected in three dimensions. Different combinations of selective excitation, inversion, or saturation pulses can be used. Sometimes, combinations of two or more measurements are necessary to define the sensitive point (or volume).

See also Magnetic Resonance Spectroscopy.
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• View the DATABASE results for 'Sensitive Point' (3).Open this link in a new window

MRI Resources 
Distributors - Service and Support - Claustrophobia - Databases - MRI Technician and Technologist Jobs - MRA
 
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