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Result : Searchterm 'Magnetic Resonance' found in 21 terms [] and 109 definitions []
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Searchterm 'Magnetic Resonance' was also found in the following services: 
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News  (787)  Resources  (181)  Forum  (1)  
 
Chemical Shift ImagingInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Spectroscopy pool -
 
(CSI) Chemical shift imaging is an extension of MR spectroscopy, allowing metabolite information to be measured in an extended region and to add the chemical analysis of body tissues to the potential clinical utility of Magnetic Resonance. The spatial location is phase encoded and a spectrum is recorded at each phase encoding step to allow the spectra acquisition in a number of volumes covering the whole sample. CSI provides mapping of chemical shifts, analog to individual spectral lines or groups of lines.
Spatial resolution can be in one, two or three dimensions, but with long acquisition times od full 3D CSI. Commonly a slice-selected 2D acquisition is used. The chemical composition of each voxel is represented by spectra, or as an image in which the signal intensity depends on the concentration of an individual metabolite. Alternatively frequency-selective pulses excite only a single spectral component.
There are several methods of performing chemical shift imaging, e.g. the inversion recovery method, chemical shift selective imaging sequence, chemical shift insensitive slice selective RF pulse, the saturation method, spatial and chemical shift encoded excitation and quantitative chemical shift imaging.

See also Magnetic Resonance Spectroscopy.
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• Related Searches:
    • Magnetic Field Mapping
    • Spatially Localized Spectroscopy
    • Spectroscopy
    • Magnetic Resonance
    • Chemical Shift Artifact
 
Further Reading:
  Basics:
1H MR Spectroscopy and Chemical Shift Imaging of the In Vivo Brain at 7 Tesla
Sunday, 26 November 2006   by tobias-lib.uni-tuebingen.de    
MRI evaluation of fatty liver in day to day practice: Quantitative and qualitative methods
Wednesday, 3 September 2014   by www.sciencedirect.com    
  News & More:
Spin echoes, CPMG and T2 relaxation - Introductory NMR & MRI from Magritek
2013   by www.azom.com    
mDIXON being developed to simplify and accelerate liver MRI
September 2010   by incenter.medical.philips.com    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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Radiology  (14) Open this link in a new windowUltrasound  (27) Open this link in a new window
Contrast Enhanced MRIInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Enhanced MRI -
 
Contrast enhanced MRI is a commonly used procedure in magnetic resonance imaging. The need to more accurately characterize different types of lesions and to detect all malignant lesions is the main reason for the use of intravenous contrast agents.
Some methods are available to improve the contrast of different tissues. The focus of dynamic contrast enhanced MRI (DCE-MRI) is on contrast kinetics with demands for spatial resolution dependent on the application. DCE-MR imaging is used for diagnosis of cancer (see also liver imaging, abdominal imaging, breast MRI, dynamic scanning) as well as for diagnosis of cardiac infarction (see perfusion imaging, cardiac MRI). Quantitative DCE-MRI requires special data acquisition techniques and analysis software.
Contrast enhanced magnetic resonance angiography (CE-MRA) allows the visualization of vessels and the temporal resolution provides a separation of arteries and veins. These methods share the need for acquisition methods with high temporal and spatial resolution.
Double contrast administration (combined contrast enhanced (CCE) MRI) uses two contrast agents with complementary mechanisms e.g., superparamagnetic iron oxide to darken the background liver and gadolinium to brighten the vessels. A variety of different categories of contrast agents are currently available for clinical use.
Reasons for the use of contrast agents in MRI scans are:
Relaxation characteristics of normal and pathologic tissues are not always different enough to produce obvious differences in signal intensity.
Pathology that is sometimes occult on unenhanced images becomes obvious in the presence of contrast.
Enhancement significantly increases MRI sensitivity.
In addition to improving delineation between normal and abnormal tissues, the pattern of contrast enhancement can improve diagnostic specificity by facilitating characterization of the lesion(s) in question.
Contrast can yield physiologic and functional information in addition to lesion delineation.
Imaging of arteries and veins with contrast enhanced angiography (CE MRA).

Common Indications:
Brain MRI : Preoperative/pretreatment evaluation and postoperative evaluation of brain tumor therapy, CNS infections, noninfectious inflammatory disease and meningeal disease.
Spine MRI : Infection/inflammatory disease, primary tumors, drop metastases, initial evaluation of syrinx, postoperative evaluation of the lumbar spine: disk vs. scar.
Breast MRI : Detection of breast cancer in case of dense breasts, implants, malignant lymph nodes, or scarring after treatment for breast cancer, diagnosis of a suspicious breast lesion in order to avoid biopsy.

For Ultrasound Imaging (USI) see Contrast Enhanced Ultrasound at Medical-Ultrasound-Imaging.com. See also Blood Pool Agents, Myocardial Late Enhancement, Cardiovascular Imaging, Contrast Enhanced MR Venography, Contrast Resolution, Dynamic Scanning, Lung Imaging, Hepatobiliary Contrast Agents, Contrast Medium and MRI Guided Biopsy.
 
Images, Movies, Sliders:
 Delayed Myocardial Contrast Enhancement from Infarct  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 Left Circumflex Ischemia First-pass Contrast Enhancement  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 Normal Lung Gd Perfusion MRI  Open this link in a new window
 MRI of the Brain Stem with Temoral Bone and Auditory System  Open this link in a new window
    
SlidersSliders Overview

 Breast MRI Images T1 Pre - Post Contrast  Open this link in a new window
 
Radiology-tip.comradContrast Enhanced Computed Tomography
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Medical-Ultrasound-Imaging.comContrast Enhanced Ultrasound,  Contrast Enhanced Doppler Imaging
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• View the DATABASE results for 'Contrast Enhanced MRI' (14).Open this link in a new window


• View the NEWS results for 'Contrast Enhanced MRI' (8).Open this link in a new window.
 
Further Reading:
  Basics:
Optimal k-Space Sampling for Dynamic Contrast-Enhanced MRI with an Application to MR Renography
Thursday, 5 November 2009   by www.ncbi.nlm.nih.gov    
  News & More:
FDA Approves Gadopiclenol for Contrast-Enhanced Magnetic Resonance Imaging
Tuesday, 27 September 2022   by www.pharmacytimes.com    
Effect of gadolinium-based contrast agent on breast diffusion-tensor imaging
Thursday, 6 August 2020   by www.eurekalert.org    
Artificial Intelligence Processes Provide Solutions to Gadolinium Retention Concerns
Thursday, 30 January 2020   by www.itnonline.com    
Accuracy of Unenhanced MRI in the Detection of New Brain Lesions in Multiple Sclerosis
Tuesday, 12 March 2019   by pubs.rsna.org    
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    
Novel Imaging Technique Improves Prostate Cancer Detection
Tuesday, 6 January 2015   by health.ucsd.edu    
New oxygen-enhanced MRI scan 'helps identify most dangerous tumours'
Thursday, 10 December 2015   by www.dailymail.co.uk    
All-organic MRI Contrast Agent Tested In Mice
Monday, 24 September 2012   by cen.acs.org    
A groundbreaking new graphene-based MRI contrast agent
Friday, 8 June 2012   by www.nanowerk.com    
MRI Resources 
Brain MRI - Knee MRI - Nerve Stimulator - MR Myelography - Musculoskeletal and Joint MRI - Research Labs
 
Coronary AngiographyMRI Resource Directory:
 - Cardiovascular Imaging -
 
(MRI-CA, MRCA) The noninvasive imaging of the coronary arteries using magnetic resonance imaging of the heart.
For cardiac MRI-CA, high performance machines are necessary with minimum 40mT/m and 300μsec slew rate.
2D and 3D acquisition are used for fast gradient echo sequences with techniques for minimizing cardiac and respiratory motion and suppressing the high signal of pericardial fat. The optimal sequences seem to be trueFISP, Balanced FFE or FIESTA with SMASH and SENSE techniques. Respiratory motion is minimized for 3D acquisitions by using respiratory gating, especially using navigator echoes (Navigator Technique) to track diaphragmatic and cardiac movement. Optimization of MR technique can provide mapping of long segments of the coronary arteries.
Blood pool agents are being applied to improve the reliability of coronary MR angiography. The major current clinical indication is the identification of coronary artery anomalies because the diagnostic accuracy's for identifying haemodynamically significant stenoses are variable depending of the image quality.

See also Magnetic Resonance Angiography, and Cardiac MRI.
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• View the DATABASE results for 'Coronary Angiography' (7).Open this link in a new window

 
Further Reading:
  Basics:
Role of Magnetic Resonance Imaging in Visualizing Coronary Arteries
Monday, 2 August 2004   by www.clinmedres.org    
  News & More:
Graphic illustration
Tuesday, 12 February 2008   by www.theengineer.co.uk    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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News  (787)  Resources  (181)  Forum  (1)  
 
Echo Planar ImagingInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
Echo Planar Imaging Timing Diagram (EPI) Echo planar imaging is one of the early magnetic resonance imaging sequences (also known as Intascan), used in applications like diffusion, perfusion, and functional magnetic resonance imaging. Other sequences acquire one k-space line at each phase encoding step. When the echo planar imaging acquisition strategy is used, the complete image is formed from a single data sample (all k-space lines are measured in one repetition time) of a gradient echo or spin echo sequence (see single shot technique) with an acquisition time of about 20 to 100 ms. The pulse sequence timing diagram illustrates an echo planar imaging sequence from spin echo type with eight echo train pulses. (See also Pulse Sequence Timing Diagram, for a description of the components.)
In case of a gradient echo based EPI sequence the initial part is very similar to a standard gradient echo sequence. By periodically fast reversing the readout or frequency encoding gradient, a train of echoes is generated.
EPI requires higher performance from the MRI scanner like much larger gradient amplitudes. The scan time is dependent on the spatial resolution required, the strength of the applied gradient fields and the time the machine needs to ramp the gradients.
In EPI, there is water fat shift in the phase encoding direction due to phase accumulations. To minimize water fat shift (WFS) in the phase direction fat suppression and a wide bandwidth (BW) are selected. On a typical EPI sequence, there is virtually no time at all for the flat top of the gradient waveform. The problem is solved by "ramp sampling" through most of the rise and fall time to improve image resolution.
The benefits of the fast imaging time are not without cost. EPI is relatively demanding on the scanner hardware, in particular on gradient strengths, gradient switching times, and receiver bandwidth. In addition, EPI is extremely sensitive to image artifacts and distortions.
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• View the DATABASE results for 'Echo Planar Imaging' (19).Open this link in a new window


• View the NEWS results for 'Echo Planar Imaging' (1).Open this link in a new window.
 
Further Reading:
  Basics:
New Imaging Method Makes Brain Scans 7 Times Faster
Sunday, 9 January 2011   by www.dailytech.com    
Searchterm 'Magnetic Resonance' was also found in the following services: 
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Radiology  (14) Open this link in a new windowUltrasound  (27) Open this link in a new window
Elscint Ltd.MRI Resource Directory:
 - Manufacturers -
 
Founded in 1969, Elscint is headquartered in Haifa, Israel. Elscint developed advanced computerized imaging systems in Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Nuclear Medicine (NM) and Mammography (MAM) for international markets.
In November 1998, General Electric Medical Systems (GEMS) acquired the Nuclear Medicine and MRI divisions of Elscint, including an unique MRI gradient system concept and technology (twin gradient system).
Elscint Ltd. signs definitive agreement to sell its Nuclear Medicine and Magnetic Resonance Imaging Businesses for $100 Million. Elscint's shareholders approved the sale of its NM, and MRI division to GE (now GE Healthcare). Picker International acquires the Computed Tomography Division of Elscint Ltd. in the same year.

See also Marconi Medical Systems.
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Further Reading:
  Basics:
Elscint's Shareholders Approved The Sale of its NM, MRI and CT Division To GE and Picker
Monday, 23 November 1998   by www.prnewswire.com    
  News & More:
Twin Gradient Technology - Potential Advantages For Diffusion Weighted MRI(.pdf)
   by www.paulrharvey.co.uk    
MRI Resources 
Nerve Stimulator - DICOM - Lung Imaging - Knee MRI - Abdominal Imaging - Education
 
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