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Result : Searchterm 'MRI Scan' found in 1 term [] and 72 definitions []
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Searchterm 'MRI Scan' was also found in the following services: 
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News  (319)  Resources  (55)  Forum  (21)  
 
MRI Procedure
 
The MRI device is located within a specially shielded room (Faraday cage) to avoid outside interference, caused by the use of radio waves very close in frequency to those of ordinary FM radio stations.
The MRI procedure can easily be performed through clothing and bones, but attention must be paid to ferromagnetic items, because they will be attracted from the magnetic field. A hospital gown is appropriate, or the patient should wear clothing without metal fasteners and remove any metallic objects like hairpins, jewelry, eyeglasses, clocks, hearing aids, any removable dental work, lighters, coins etc., not only for MRI safety reasons. Metal in or around the scanned area can also cause errors in the reconstructed images (artifacts). Because the strong magnetic field can displace, or disrupt metallic objects, people with an implanted active device like a cardiac pacemaker cannot be scanned under normal circumstances and should not enter the MRI area.
The MRI machine can look like a short tunnel or has an open MRI design and the magnet does not completely surround the patient. Usually the patient lies on a comfortable motorized table, which slides into the scanner, depending on the MRI device, patients may be also able to sit up. If a contrast agent is to be administered, intravenous access will be placed. A technologist will operate the MRI machine and observe the patient during the examination from an adjacent room. Several sets of images are usually required, each taking some minutes. A typical MRI scan includes three to nine imaging sequences and may take up to one hour. Improved MRI devices with powerful magnets, newer software, and advanced sequences may complete the process in less time and better image quality.
Before and after the most MRI procedures no special preparation, diet, reduced activity, and extra medication is necessary. The magnetic field and radio waves are not felt and no pain is to expect.
Movement can blur MRI images and cause certain artifacts. A possible problem is the claustrophobia that some patients experience from being inside a tunnel-like scanner. If someone is very anxious or has difficulty to lie still, a sedative agent may be given. Earplugs and/or headphones are usually given to the patient to reduce the loud acoustic noise, which the machine produces during normal operation. A technologist observes the patient during the test. Some MRI scanners are equipped with televisions and music to help the examination time pass.
MRI is not a cheap examination, however cost effective by eliminating the need for invasive radiographic procedures, biopsies, and exploratory surgery. MRI scans can also save money while minimizing patient risk and discomfort. For example, MRI can reduce the need for X-ray angiography and myelography, and can eliminate unnecessary diagnostic procedures that miss occult disease.

See also Magnetic Resonance Imaging MRI, Medical Imaging, Cervical Spine MRI, Claustrophobia, MRI Risks and Pregnancy.
For Ultrasound Imaging (USI) see Ultrasound Imaging Procedures at Medical-Ultrasound-Imaging.com.

See also the related poll result: 'MRI will have replaced 50% of x-ray exams by'
 
Images, Movies, Sliders:
 Brain MRI Images Axial T2  Open this link in a new window
      

 Circle of Willis, Time of Flight, MIP  Open this link in a new window
    
SlidersSliders Overview

 CE-MRA of the Carotid Arteries  Open this link in a new window
    
SlidersSliders Overview

 Breast MRI Images T2 And T1 Pre - Post Contrast  Open this link in a new window
 Sagittal Knee MRI Images T1 Weighted  Open this link in a new window
      

 
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• Related Searches:
    • Brain MRI
    • MRI History
    • Contrast Medium
    • Claustrophobia
    • Pulse Sequence
 
Further Reading:
  News & More:
MRI technology visualizes heart metabolism in real time
Friday, 18 November 2022   by medicalxpress.com    
Are synthetic contrast-enhanced breast MRI images as good as the real thing?
Friday, 18 November 2022   by healthimaging.com    
Ultrafast MRI protocol reduces scan time by 10 minutes for cervical imaging
Monday, 26 September 2022   by healthimaging.com    
Study: Fast MRI can diagnose TBI without radiation
Wednesday, 18 September 2019   by www.aappublications.org    
Metamaterials boost sensitivity of MRI machines
Thursday, 14 January 2016   by www.eurekalert.org    
Working with MRI machines may cause vertigo: Study
Wednesday, 25 June 2014   by www.cos-mag.com    
Searchterm 'MRI Scan' was also found in the following services: 
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Ultrasound  (1) Open this link in a new window
Breath Hold ImagingMRI Resource Directory:
 - Abdominal Imaging -
 
Breath hold imaging in MRI is a technique with one ore more stoppage of breathing during the sequence and require therefore a short scan time. Breath hold techniques are used with fast gradient echo sequences in thoracic or abdominal regions with much respiratory movement.
Breath hold cine MRI techniques are used in cardiovascular imaging and provide detailed views of the beating heart in different cardiac axes.
Breath hold imaging requires the full cooperation of the patient, caused by usual MRI scan times from 15 to 20 sec.. In some cases breath holding can be practiced outside the MRI scanner to improve patient cooperation with the examination. Shorter scan times e.g. by parallel imaging techniques, or the administration of oxygen can help the patient to hold the breath during the scan.
See also Abdominal Imaging.
 
Images, Movies, Sliders:
 MRI Upper Abdomen T1 with Contrast  Open this link in a new window
 Normal Dual Inversion Fast Spin-echo  Open this link in a new window
 Anatomic Imaging of the Lungs  Open this link in a new window
 
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• View the DATABASE results for 'Breath Hold Imaging' (7).Open this link in a new window

 
Further Reading:
  News & More:
The Effects of Breathing Motion on DCE-MRI Images: Phantom Studies Simulating Respiratory Motion to Compare CAIPIRINHA-VIBE, Radial-VIBE, and Conventional VIBE
Tuesday, 7 February 2017   by www.kjronline.org    
Controlling patient's breathing makes cardiac MRI more accurate
Friday, 13 May 2016   by www.upi.com    
Accurate T1 Quantification Using a Breath-hold Inversion Recovery TrueFISP Sequence
2003   by rsna2003.rsna.org    
MRI Resources 
Developers - NMR - Open Directory Project - Software - Libraries - Lung Imaging
 
Cervical Spine MRI
 
Cervical spine MRI is a suitable tool in the assessment of all cervical spine (vertebrae C1 - C7) segments (computed tomography (CT) images may be unsatisfactory close to the thoracic spine due to shoulder artifacts). The cervical spine is particularly susceptible to degenerative problems caused by the complex anatomy and its large range of motion.
Advantages of magnetic resonance imaging MRI are the high soft tissue contrast (particularly important in diagnostics of the spinal cord), the ability to display the entire spine in sagittal views and the capacity of 3D visualization. Magnetic resonance myelography is a useful supplement to conventional MRI examinations in the investigation of cervical stenosis. Myelographic sequences result in MR images with high contrast that are similar in appearance to conventional myelograms. Additionally, open MRI studies provide the possibility of weight-bearing MRI scan to evaluate structural positional and kinetic changes of the cervical spine.
Indications of cervical spine MRI scans include the assessment of soft disc herniations, suspicion of disc hernia recurrence after operation, cervical spondylosis, osteophytes, joint arthrosis, spinal canal lesions (tumors, multiple sclerosis, etc.), bone diseases (infection, inflammation, tumoral infiltration) and paravertebral spaces.
State-of-the-art phased array spine coils and high performance MRI machines provide high image quality and short scan time. Imaging protocols for the cervical spine includes sagittal T1 weighted and T2 weighted sequences with 3-4 mm slice thickness and axial slices; usually contiguous from C2 through T1. Additionally, T2 fat suppressed and T1 post contrast images are often useful in spine imaging.

See also Lumbar Spine MRI.
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• View the DATABASE results for 'Cervical Spine MRI' (2).Open this link in a new window


• View the NEWS results for 'Cervical Spine MRI' (1).Open this link in a new window.
 
Further Reading:
  News & More:
Ultrafast MRI protocol reduces scan time by 10 minutes for cervical imaging
Monday, 26 September 2022   by healthimaging.com    
In Vivo 3-D Cervical Spine Kinematics Demonstrated
Thursday, 19 May 2011   by www.doctorslounge.com    
MRI Images at a 45-Degree Angle Through The Cervic al Neural Forami na:A Technique For Improved Visualization(.pdf)
2006   by www.painphysicianjournal.com    
Searchterm 'MRI Scan' was also found in the following services: 
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News  (319)  Resources  (55)  Forum  (21)  
 
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.
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• View the DATABASE results for 'MR Compatibility' (4).Open this link in a new window


• 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 'MRI Scan' was also found in the following services: 
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Ultrasound  (1) Open this link in a new window
MRI History
 
•
Sir Joseph Larmor (1857-1942) developed the equation that the angular frequency of precession of the nuclear spins being proportional to the strength of the magnetic field. [Larmor relationship]
•
In the 1930's, Isidor Isaac Rabi (Columbia University) succeeded in detecting and measuring single states of rotation of atoms and molecules, and in determining the mechanical and magnetic moments of the nuclei.
•
Felix Bloch (Stanford University) and Edward Purcell (Harvard University) developed instruments, which could measure the magnetic resonance in bulk material such as liquids and solids. (Both honored with the Nobel Prize for Physics in 1952.) [The birth of the NMR spectroscopy]
•
In the early 70's, Raymond Damadian (State University of New York) demonstrated with his NMR device, that there are different T1 relaxation times between normal and abnormal tissues of the same type, as well as between different types of normal tissues.
•
In 1973, Paul Lauterbur (State University of New York) described a new imaging technique that he termed Zeugmatography. By utilizing gradients in the magnetic field, this technique was able to produce a two-dimensional image (back-projection). (Through analysis of the characteristics of the emitted radio waves, their origin could be determined.) Peter Mansfield further developed the utilization of gradients in the magnetic field and the mathematically analysis of these signals for a more useful imaging technique. (Paul C Lauterbur and Peter Mansfield were awarded with the 2003 Nobel Prize in Medicine.)
•
In 1975, Richard Ernst introduced 2D NMR using phase and frequency encoding, and the Fourier Transform. Instead of Paul Lauterbur's back-projection, he timely switched magnetic field gradients ('NMR Fourier Zeugmatography'). [This basic reconstruction method is the basis of current MRI techniques.]
•
1977/78: First images could be presented. A cross section through a finger by Peter Mansfield and Andrew A. Maudsley. Peter Mansfield also could present the first image through the abdomen.
•
In 1977, Raymond Damadian completed (after 7 years) the first MR scanner (Indomitable). In 1978, he founded the FONAR Corporation, which manufactured the first commercial MRI scanner in 1980. Fonar went public in 1981.
•
1981: Schering submitted a patent application for Gd-DTPA dimeglumine.
•
1982: The first 'magnetization-transfer' imaging by Robert N. Muller.
•
In 1983, Toshiba obtained approval from the Ministry of Health and Welfare in Japan for the first commercial MRI system.
•
In 1984, FONAR Corporation receives FDA approval for its first MRI scanner.
•
1986: Jürgen Hennig, A. Nauerth, and Hartmut Friedburg (University of Freiburg) introduced RARE (rapid acquisition with relaxation enhancement) imaging. Axel Haase, Jens Frahm, Dieter Matthaei, Wolfgang Haenicke, and Dietmar K. Merboldt (Max-Planck-Institute, Göttingen) developed the FLASH (fast low angle shot) sequence.
•
1988: Schering's MAGNEVIST gets its first approval by the FDA.
•
In 1991, fMRI was developed independently by the University of Minnesota's Center for Magnetic Resonance Research (CMRR) and Massachusetts General Hospital's (MGH) MR Center.
•
From 1992 to 1997 Fonar was paid for the infringement of it's patents from 'nearly every one of its competitors in the MRI industry including giant multi-nationals as Toshiba, Siemens, Shimadzu, Philips and GE'.
•
 
Images, Movies, Sliders:
 Cardiac Infarct Short Axis Cine Overview  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 
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• View the DATABASE results for 'MRI History' (6).Open this link in a new window


• View the NEWS results for 'MRI History' (1).Open this link in a new window.
 
Further Reading:
  Basics:
Magnetic Resonance Imaging, History & Introduction
2000   by www.cis.rit.edu    
A Short History of the Magnetic Resonance Imaging (MRI)
   by www.teslasociety.com    
Fonar Our History
   by www.fonar.com    
  News & More:
Scientists win Nobels for work on MRI
Tuesday, 10 June 2003   by usatoday30.usatoday.com    
2001 Lemelson-MIT Lifetime Achievement Award Winner
   by web.mit.edu    
MRI's inside story
Thursday, 4 December 2003   by www.economist.com    
MRI Resources 
Breast MRI - Safety Products - Spectroscopy - General - Mobile MRI Rental - MR Guided Interventions
 
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