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Result : Searchterm 'Functional Magnetic Resonance Imaging' found in 1 term [] and 7 definitions [], (+ 3 Boolean[] results
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Functional Magnetic Resonance ImagingMRI Resource Directory:
 - Functional MRI -
 
(fMRI) Functional magnetic resonance imaging is a technique used to determine the dynamic brain function, often based on echo planar imaging, but can also be performed by using contrast agents and observing their first pass effects through brain tissue. Functional magnetic resonance imaging allows insights in a dysfunctional brain as well as into the basic workings of the brain.
The in functional brain MRI most frequently used effect to assess brain function is the blood oxygenation level dependent contrast (BOLD) effect, in which differential changes in brain perfusion and their resultant effect on the regional distribution of oxy- to deoxyhaemoglobin are observable because of the different 'intrinsic contrast media' effects of the two haemoglobin forms. Increased brain activity causes an increased demand for oxygen, and the vascular system actually overcompensates for this, increasing the amount of oxygenated haemoglobin. Because deoxygenated haemoglobin attenuates the MR signal, the vascular response leads to a signal increase that is related to the neural activity.
Functional imaging relates body function or thought to specific locations where the neural activity is taking place. The brain is scanned at low resolution but at a fast rate (typically once every 2-3 seconds). Structural MRI together with fMRI provides an anatomical baseline and best spatial resolution.
Interactions can also be seen from the motor cortex to the cerebellum or basal ganglia in the case of a movement disorder such as ataxia. For example: by a finger movement the briefly increase in the blood circulation of the appropriate part of the brain controlling that movement, can be measured.
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Further Reading:
  Basics:
IMAGE CONTRAST IN MRI(.pdf)
   by www.assaftal.com    
High-Resolution, Spin-Echo BOLD, and CBF fMRI at 4 and 7 T(.pdf)
October 2002   by otg.downstate.edu    
Vascular Filters of Functional MRI: Spatial Localization Using BOLD and CBV Contrast
  News & More:
Functional MRI may help identify new, effective painkillers for chronic pain sufferers
Thursday, 4 February 2016   by www.eurekalert.org    
Study shows functional MRI differences in working memory in people with primary insomnia
Saturday, 31 August 2013   by www.news-medical.net    
fMRI leads to mind-reading speller and a way for people in a coma to speak
Sunday, 1 July 2012   by www.sciencecodex.com    
Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state.
Tuesday, 31 August 2010   by 7thspace.com    
Functional magnetic resonance imaging may improve diagnosis of autism
Tuesday, 31 May 2011   by www.dnaindia.com    
Using fMRI to study brain development
Friday, 30 November 2007   by www.eurekalert.org    
Searchterm 'Functional Magnetic Resonance Imaging' was also found in the following services: 
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Brain MRIForum -
related threadsMRI Resource Directory:
 - Brain MRI -
 
Brain imaging, magnetic resonance imaging of the head or skull, cranial magnetic resonance tomography (MRT), neurological MRI - they describe all the same radiological imaging technique for medical diagnostic.
Magnetic resonance imaging of the human brain includes the anatomic description and the detection of lesions. Special techniques like diffusion weighted imaging, functional magnetic resonance imaging (fMRI) and spectroscopy provide also information about the function and chemical metabolites of the brain. MRI provides detailed pictures of brain and nerve tissues in multiple planes without obstruction by overlying bones. Brain MRI is the procedure of choice for most brain disorders. It provides clear images of the brainstem and posterior brain, which are difficult to view on a CT scan. It is also useful for the diagnosis of demyelinating disorders (disorders such as multiple sclerosis (MS) that cause destruction of the myelin sheath of the nerve).
With this noninvasive procedure also the evaluation of blood flow and the flow of cerebrospinal fluid (CSF) is possible. Different MRA methods, also without contrast agents can show a venous or arterial angiogram. MRI can distinguish tumors, inflammatory lesions, and other pathologies from the normal brain anatomy. However, MRI scans are also used instead other methods to avoid the dangers of interventional procedures like angiography (DSA - digital subtraction angiography) as well as of repeated exposure to radiation as required for computed tomography (CT) and other X-ray examinations.
A (birdcage) bird cage coil achieves uniform excitation and reception and is commonly used to study the brain. Usually a brain MRI procedure includes FLAIR, T2 weighted and T1 weighted sequences in two or three planes.
See also Fetal MRI, Fluid Attenuation Inversion Recovery (FLAIR), Perfusion Imaging and High Field MRI.
See also Arterial Spin Labeling.
 
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Further Reading:
  Basics:
New MRI technique offers faster diagnosis of multiple sclerosis
Monday, 1 February 2016   by medicalxpress.com    
Ultra-high-field MRI reveals language centres in the brain in much more detail
Tuesday, 28 October 2014   by medicalxpress.com    
Neuro-Oncology - Diagnosis MRI with Gd-DTPA
A Dutch study has revealed that as many as 13% of healthy adults may have some type of undiagnosed abnormality in the brain.
Sunday, 4 November 2007   by www.news-medical.net:80    
  News & More:
Talking therapy or medication for depression: Brain scan may help suggest better treatment
Monday, 27 March 2017   by www.newsnation.in    
MRI identifies brain abnormalities in chronic fatigue syndrome patients
Wednesday, 29 October 2014   by www.eurekalert.org    
Contrast agent linked with brain abnormalities on MRI
Tuesday, 17 December 2013   by www.sciencecodex.com    
MRIs Useful in Tracking Depression in MS Patients
Tuesday, 1 July 2014   by www.hcplive.com    
MRIs Reveal Signs of Brain Injuries Not Seen in CT Scans
Tuesday, 18 December 2012   by www.sciencedaily.com    
Iron Deposits in the Brain May Be Early Indicator of MS
Wednesday, 13 November 2013   by www.healthline.com    
Migraine Sufferers Have Thicker Brain Cortex
Tuesday, 20 November 2007   by www.medicalnewstoday.com    
MRI Resources 
MRI Technician and Technologist Schools - PACS - Abdominal Imaging - Stimulator pool - Intraoperative MRI - Equipment
 
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 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 'Functional Magnetic Resonance Imaging' was also found in the following services: 
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HaemoglobinInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
(Hb) Haemoglobin is the major endogenous oxygen-binding molecule, responsible for binding oxygen in the lung and transporting it to the tissues by means of the circulation. Haemoglobin is contained in very high concentration in the red blood cells.
Haemoglobin is an Fe chelate tightly binding one Fe ion in its II oxidation state where it carries the charge 2+ (ferrous iron). If an oxygen molecule is bound to Hb, Hb is called oxyhaemoglobin, if no oxygen molecule is bound it is called deoxyhaemoglobin. When haemoglobin is oxidized (i.e. in a haematoma), Fe2+ is transformed into Fe3+. The resulting haemoglobin is then called metoxyhaemoglobin (Hb Fe3+).
Deoxyhaemoglobin and metoxyhaemoglobin act as paramagnetic contrast agents in MR, while oxyhaemoglobin is diamagnetic. This partly explains the special appearance of an aging haematoma in MR imaging and is also the basic of the blood oxygenation level dependent contrast (BOLD) used in functional magnetic resonance imaging of the brain (fMRI).
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Further Reading:
  Basics:
MRI's inside story
Thursday, 4 December 2003   by www.economist.com    
  News & More:
MRI effectively measures hemochromatosis iron burden
Saturday, 3 October 2015   by medicalxpress.com    
Iron overload: accuracy of in-phase and out-of-phase MRI as a quick method to evaluate liver iron load in haematological malignancies and chronic liver disease
Friday, 1 June 2012   by www.ncbi.nlm.nih.gov    
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
Searchterm 'Functional Magnetic Resonance Imaging' was also found in the following services: 
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Magnetic Resonance Imaging MRI
 
(MRI) Magnetic resonance imaging is a noninvasive medical imaging technique that uses the interaction between radio frequency pulses, a strong magnetic field and body tissue to obtain images of slices/planes from inside the body. These magnets generate fields from approx. 2000 times up to 30000 times stronger than that of the Earth. The use of nuclear magnetic resonance principles produces extremely detailed pictures of the body tissue without the need for x-ray exposure and gives diagnostic information of various organs.
Measured are mobile hydrogen nuclei (protons are the hydrogen atoms of water, the 'H' in H20), the majority of elements in the body. Only a small part of them contribute to the measured signal, caused by their different alignment in the magnetic field. Protons are capable of absorbing energy if exposed to short radio wave pulses (electromagnetic energy) at their resonance frequency. After the absorption of this energy, the nuclei release this energy so that they return to their initial state of equilibrium.
This transmission of energy by the nuclei as they return to their initial state is what is observed as the MRI signal. The subtle differing characteristic of that signal from different tissues combined with complex mathematical formulas analyzed on modern computers is what enables MRI imaging to distinguish between various organs. Any imaging plane, or slice, can be projected, and then stored or printed.
The measured signal intensity depends jointly on the spin density and the relaxation times (T1 time and T2 time), with their relative importance depending on the particular imaging technique and choice of interpulse times. Any motion such as blood flow, respiration, etc. also affects the image brightness.
Magnetic resonance imaging is particularly sensitive in assessing anatomical structures, organs and soft tissues for the detection and diagnosis of a broad range of pathological conditions. MRI pictures can provide contrast between benign and pathological tissues and may be used to stage cancers as well as to evaluate the response to treatment of malignancies. The need for biopsy or exploratory surgery can be eliminated in some cases, and can result in earlier diagnosis of many diseases.
See also MRI History and Functional Magnetic Resonance Imaging (fMRI).
 
Images, Movies, Sliders:
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Courtesy of  Robert R. Edelman

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Courtesy of  Robert R. Edelman

 Breast MRI Images T2 And T1 Pre - Post Contrast  Open this link in a new window
 Anatomic Imaging of the Shoulder  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 
Radiology-tip.comConventional Radiography,  Computed Tomography
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Radiology-tip.comUltrasound Imaging,  Ultrasound Imaging Procedures
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• View the DATABASE results for 'Magnetic Resonance Imaging MRI' (9).Open this link in a new window


• View the NEWS results for 'Magnetic Resonance Imaging MRI' (222).Open this link in a new window.
 
Further Reading:
  Basics:
A Short History of the Magnetic Resonance Imaging (MRI)
   by www.teslasociety.com    
MRI's inside story
Thursday, 4 December 2003   by www.economist.com    
On the Horizon - Next Generation MRI
Wednesday, 23 October 2013   by thefutureofthings.com    
  News & More:
Metamaterials boost sensitivity of MRI machines
Thursday, 14 January 2016   by www.eurekalert.org    
MRI technique allows study of wrist in motion
Monday, 6 January 2014   by www.healthimaging.com    
New imaging technology promising for several types of cancer
Thursday, 29 August 2013   by medicalxpress.com    
Study Shows MRI Can Be Used for Orthodontic Imaging
Monday, 12 August 2013   by www.sbwire.com    
MRI method for measuring MS progression validated
Thursday, 19 December 2013   by www.eurekalert.org    
The 2003 Nobel Prize in Physiology or Medicine
2003   by www.nobel.se    
MRI Resources 
Chemistry - Service and Support - Artifacts - Spectroscopy pool - Implant and Prosthesis pool - Functional MRI
 
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