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Result : Searchterm 'Volume Coil' found in 1 term [] and 4 definitions [], (+ 18 Boolean[] results
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Volume CoilInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
Radio frequency coil that surrounds either the whole body, or one specific region, such as the head or a knee. Volume coils have a better RF homogeneity than surface coils, which extends over a large area. The most commonly used design is a (birdcage) bird cage coil. This consists of a number of wires running along the z-direction, arranged to give a cosine current variation around the circumference of the coil. It is possible to use the same coil to transmit and receive, or to use two separate coils. The largest volume coil, the body coil is typically a transmit and receive coil. If two separate coils are used, works the body coil as the transmitter and a smaller coil as the receiver.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'
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• Related Searches:
    • Bird Cage Coil
    • Volume Selective Excitation
    • Quadrature Coil
    • Radio Frequency Coil
    • Imaging Coil
 
Further Reading:
  News & More:
HEAD AND NECK MRI GRADIENT COIL DESIGN
Thursday, 26 August 1999   by www.imaging.robarts.ca    
MRI Resources 
Mass Spectrometry - Anatomy - Used and Refurbished MRI Equipment - Distributors - Lung Imaging - Bioinformatics
 
Bird Cage CoilInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
A RF coil, often a transmit receive coil with a number of wires running along the z-direction, arranged to give a cosine current variation around the circumference of the coil, which looks like a bird cage. The bird cage coil works on a different principle to conventionally tuned local and surround coils in that it behaves like a tuned transmission line with one complete cycle of standing wave around the circumference. The frequency supply is generated by an oscillator, which is modulated to form a shaped pulse by a product detector controlled by the waveform generator. The signal must be amplified to 1000's of watts. This can be done using either solid state electronics, valves or a combination of both.
The bird cage coil design provides the best field homogeneity of all RF imaging coils.
One advantage is that it is simple to produce an exceedingly uniform B1 radio frequency field over most of the coil's volume, with the result of images with a high degree of uniformity.
A second advantage is that nodes with zero voltage occur 90° away from the driven part of the coil, thus facilitating the introduction of a second signal in quadrature, which produces a circularly polarized radio frequency field.
This type of volume coil is used for brain (head) MRI, or MR imaging of joints, such as the wrist or knees.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'
 
Images, Movies, Sliders:
 Brain MRI Images T1  Open this link in a new window
 Anatomic MRI of the Knee 1  Open this link in a new window
    
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 MRI of the Brain Stem with Temoral Bone and Auditory System  Open this link in a new window
    
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• View the DATABASE results for 'Bird Cage Coil' (4).Open this link in a new window

 
Further Reading:
  Basics:
HEAD AND NECK MRI GRADIENT COIL DESIGN
Thursday, 26 August 1999   by www.imaging.robarts.ca    
System Architecture
2003   by www.revisemri.com    
  News & More:
On the Horizon - Next Generation MRI
Wednesday, 23 October 2013   by thefutureofthings.com    
TOSHIBA INTRODUCES 32 ELEMENT COILS FOR ITS VANTAGE TITAN MR SYSTEMS
Tuesday, 9 November 2010   by medical.toshiba.com    
MRI Resources 
Diffusion Weighted Imaging - Contrast Agents - Abdominal Imaging - Research Labs - Liver Imaging - Equipment
 
DeviceForum -
related threadsInfoSheet: - Devices -
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Types of Magnets, 
Overview, 
etc.
 
Magnetic resonance imaging (MRI) is based on the magnetic resonance phenomenon, and is used for medical diagnostic imaging since ca. 1977 (see also MRI History).
The first developed MRI devices were constructed as long narrow tunnels. In the meantime the magnets became shorter and wider. In addition to this short bore magnet design, open MRI machines were created. MRI machines with open design have commonly either horizontal or vertical opposite installed magnets and obtain more space and air around the patient during the MRI test.
The basic hardware components of all MRI systems are the magnet, producing a stable and very intense magnetic field, the gradient coils, creating a variable field and radio frequency (RF) coils which are used to transmit energy and to encode spatial positioning. A computer controls the MRI scanning operation and processes the information.
The range of used field strengths for medical imaging is from 0.15 to 3 T. The open MRI magnets have usually field strength in the range 0.2 Tesla to 0.35 Tesla. The higher field MRI devices are commonly solenoid with short bore superconducting magnets, which provide homogeneous fields of high stability.
There are this different types of magnets:
Resistive Magnet
Permanent Magnet
Superconducting Magnet
The majority of superconductive magnets are based on niobium-titanium (NbTi) alloys, which are very reliable and require extremely uniform fields and extreme stability over time, but require a liquid helium cryogenic system to keep the conductors at approximately 4.2 Kelvin (-268.8 Celsius). To maintain this temperature the magnet is enclosed and cooled by a cryogen containing liquid helium (sometimes also nitrogen).
The gradient coils are required to produce a linear variation in field along one direction, and to have high efficiency, low inductance and low resistance, in order to minimize the current requirements and heat deposition. A Maxwell coil usually produces linear variation in field along the z-axis; in the other two axes it is best done using a saddle coil, such as the Golay coil.
The radio frequency coils used to excite the nuclei fall into two main categories; surface coils and volume coils. The essential element for spatial encoding, the gradient coil sub-system of the MRI scanner is responsible for the encoding of specialized contrast such as flow information, diffusion information, and modulation of magnetization for spatial tagging.
An analog to digital converter turns the nuclear magnetic resonance signal to a digital signal. The digital signal is then sent to an image processor for Fourier transformation and the image of the MRI scan is displayed on a monitor.

For Ultrasound Imaging (USI) see Ultrasound Machine at US-TIP.com.

See also the related poll results: 'In 2010 your scanner will probably work with a field strength of' and 'Most outages of your scanning system are caused by failure of'
Radiology-tip.comGamma Camera,  Linear Accelerator
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Radiology-tip.comUltrasound Machine,  Real-Time Scanner
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• View the DATABASE results for 'Device' (141).Open this link in a new window


• View the NEWS results for 'Device' (29).Open this link in a new window.
 
Further Reading:
  News & More:
Kyoto University and Canon reduce cost of MRI scanner to one tenth
Monday, 11 January 2016   by www.electronicsweekly.com    
A transportable MRI machine to speed up the diagnosis and treatment of stroke patients
Wednesday, 22 April 2015   by medicalxpress.com    
Portable 'battlefield MRI' comes out of the lab
Thursday, 30 April 2015   by physicsworld.com    
Chemists develop MRI technique for peeking inside battery-like devices
Friday, 1 August 2014   by www.eurekalert.org    
New devices doubles down to detect and map brain signals
Monday, 23 July 2012   by scienceblog.com    
Searchterm 'Volume Coil' was also found in the following service: 
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Imaging CoilInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
Imaging coils are radio frequency coils used in magnetic resonance imaging for sending and/or receiving electromagnetic radiation. Several MR imaging coils in different shapes and sizes are necessary for different body parts and to handle individual applications.
For Example:
Birdcage coils provide high homogeneity and good signal to noise ratio (SNR) in brain MRI scans.
Surface coils with small coil diameter and higher SNR enable to image the temporomandibular joints (TMJ).
The implemented body coil allows the scanning of body parts with large field of views.
Micro coils are available to image finger joints.
High performance phased array coils are today state-of-the-art for a wide range of applications from head, spine, knee or shoulder to cardiac MRI.
For different types of coils see Volume Coil, Sense Coil, Array Coil, Surface Coil, and Bird Cage Coil.

See also the related poll result: '3rd party coils are better than the original manufacturer coils'
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• View the DATABASE results for 'Imaging Coil' (7).Open this link in a new window


• View the NEWS results for 'Imaging 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    
MRI Resources 
Supplies - Claustrophobia - Most Wanted - MRI Technician and Technologist Jobs - Chemistry - Safety pool
 
Multi Turn SolenoidInfoSheet: - Coils - 
Intro, 
Overview, 
etc.MRI Resource Directory:
 - Coils -
 
The multi turn solenoid is a volume coil that typically operates as the transmitter and receiver of RF energy. Multi turn solenoids can be wrapped, but the uniformity of the field suffers.
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• View the DATABASE results for 'Multi Turn Solenoid' (2).Open this link in a new window

 
Further Reading:
  Basics:
RF Coils in MRI
Sunday, 1 January 2006   by ric.uthscsa.edu    
MRI Resources 
Universities - Fluorescence - Used and Refurbished MRI Equipment - MRI Technician and Technologist Career - Sequences - Liver Imaging
 
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