Magnetic Resonance - Technology Information Portal Welcome to MRI Technology
Info
  Sheets


Out-
      side
 



 
Dear Guest, Your Attention Please:  


In the next days, the daily page limit for non-members will decrease to 20 pages to split up resources in favour of the MR-TIP Community. Beyond this limitation, most resources will still be available for everyone. If you want to join the MR-TIP Community, please register here.


 'Diffusion Weighted Imaging' 
SEARCH FOR    
 
  2 3 5 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Result : Searchterm 'Diffusion Weighted Imaging' found in 1 term [] and 10 definitions [], (+ 3 Boolean[] results
1 - 5 (of 14)     next
Result Pages : [1]  [2 3]
Searchterm 'Diffusion Weighted Imaging' was also found in the following services: 
spacer
News  (6)  Resources  (2)  Forum  (2)  
 
Diffusion Weighted ImagingForum -
related threadsMRI Resource Directory:
 - Diffusion Weighted Imaging -
 
(DWI) Magnetic resonance imaging is sensitive to diffusion, because the diffusion of water molecules along a field gradient reduces the MR signal. In areas of lower diffusion the signal loss is less intense and the display from this areas is brighter. The use of a bipolar gradient pulse and suitable pulse sequences permits the acquisition of diffusion weighted images (images in which areas of rapid proton diffusion can be distinguished from areas with slow diffusion).
Based on echo planar imaging, multislice DWI is today a standard for imaging brain infarction. With enhanced gradients, the whole brain can be scanned within seconds. The degree of diffusion weighting correlates with the strength of the diffusion gradients, characterized by the b-value, which is a function of the gradient related parameters: strength, duration, and the period between diffusion gradients.
Certain illnesses show restrictions of diffusion, for example demyelinization and cytotoxic edema. Areas of cerebral infarction have decreased apparent diffusion, which results in increased signal intensity on diffusion weighted MRI scans. DWI has been demonstrated to be more sensitive for the early detection of stroke than standard pulse sequences and is closely related to temperature mapping.
DWIBS is a new diffusion weighted imaging technique for the whole body that produces PET-like images. The DWIBS sequence has been developed with the aim to detect lymph nodes and to differentiate normal and hyperplastic from metastatic lymph nodes. This may be possible caused by alterations in microcirculation and water diffusivity within cancer metastases in lymph nodes.
See also Diffusion Weighted Sequence, Perfusion Imaging, ADC Map, Apparent Diffusion Coefficient, and Diffusion Tensor Imaging.

spacer
 
• Share the entry 'Diffusion Weighted Imaging':  Facebook  Twitter  LinkedIn  
 
• Related Searches:
    • Brain MRI
    • Attenuation
    • Boltzmann Distribution
    • Molecule
    • Diffusion Tensor Tractography
 
Further Reading:
  Basics:
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
Novel MRI Technique Could Reduce Breast Biopsies, University of Washington Study
Tuesday, 2 October 2012   by www.eurekalert.org    
Quantitative Apparent Diffusion Coefficient Measurements Obtained by 3-Tesla MRI Are Correlated with Biomarkers of Bladder Cancer Proliferative Activity
   by www.plosone.org    
  News & More:
Use of diffusion magnetic resonance imaging to correlate the developmental changes in grape berry tissue structure with water diffusion patterns
Wednesday, 5 November 2014   by 7thspace.com    
Novel Imaging Technique Improves Prostate Cancer Detection
Tuesday, 6 January 2015   by health.ucsd.edu    
High-b-value Diffusion-weighted MR Imaging of Suspected Brain Infarction
2000   by www.ajnr.org    
MRI Resources 
DICOM - Implant and Prosthesis - Journals - MRI Technician and Technologist Career - RIS - Pathology
 
Apparent Diffusion CoefficientInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Diffusion Weighted Imaging -
 
(ADC) A diffusion coefficient to differentiate T2 shine through effects or artifacts from real ischemic lesions. In the human brain, water diffusion is a three-dimensional process that is not truly random because the diffusional motion of water is impeded by natural barriers. These barriers are cell membranes, myelin sheaths, white matter fiber tracts, and protein molecules.
The apparent water diffusion coefficients can be calculated by acquiring two or more images with a different gradient duration and amplitude (b-values). The contrast in the ADC map depends on the spatially distributed diffusion coefficient of the acquired tissues and does not contain T1 and T2* values.
The increased sensitivity of diffusion-weighted MRI in detecting acute ischemia is thought to be the result of the water shift intracellularly restricting motion of water protons (cytotoxic edema), whereas the conventional T2 weighted images show signal alteration mostly as a result of vasogenic edema.
The reduced ADC value also could be the result of decreased temperature in the nonperfused tissues, loss of brain pulsations leading to a decrease in apparent proton motion, increased tissue osmolality associated with ischemia, or a combination of these factors. The lower ADC measurements seen with early ischemia, have not been fully established, however, a lower apparent ADC is a sensitive indicator of early ischemic brain at a stage when ischemic tissue remains potentially salvageable.
See also Diffusion Weighted Imaging and Diffusion Tensor Tractography.
spacer

• View the DATABASE results for 'Apparent Diffusion Coefficient' (4).Open this link in a new window

 
Further Reading:
  Basics:
Implementation of Dual-Source RF Excitation in 3 T MR-Scanners Allows for Nearly Identical ADC Values Compared to 1.5 T MR Scanners in the Abdomen
Wednesday, 29 February 2012   by www.plosone.org    
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
Diffusion Imaging: From Basic Physics to Practical Imaging
1999   by ej.rsna.org    
  News & More:
EORTC study aims to qualify ADC as predictive imaging biomarker in preoperative regimens
Monday, 4 January 2016   by www.eurekalert.org    
Novel MRI Technique Could Reduce Breast Biopsies, University of Washington Study
Tuesday, 2 October 2012   by www.eurekalert.org    
Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state.
Tuesday, 31 August 2010   by 7thspace.com    
Hopkins researchers use diffusion MRI technique to monitor ultrasound uterine fibroid treatment
Monday, 8 August 2005   by www.eurekalert.org    
MRI Resources 
Breast MRI - MRI Centers - Jobs pool - Universities - Directories - Shielding
 
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.
 
Images, Movies, Sliders:
 Brain MRI Images Axial T2  Open this link in a new window
      

 MRI of the Skull Base  Open this link in a new window
    
SlidersSliders Overview

 Anatomic Imaging of the Orbita  Open this link in a new window
      

 Brain MRI Images T1  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

 TOF-MRA Circle of Willis Inverted MIP  Open this link in a new window
    

 PCA-MRA 3D Brain Venography Colored MIP  Open this link in a new window
    

 
Radiology-tip.comA-Mode
spacer

• View the DATABASE results for 'Brain MRI' (14).Open this link in a new window


• View the NEWS results for 'Brain MRI' (32).Open this link in a new window.
 
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:
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    
Searchterm 'Diffusion Weighted Imaging' was also found in the following services: 
spacer
News  (6)  Resources  (2)  Forum  (2)  
 
DiffusionForum -
related threads
 
The process by which molecules or other particles intermingle and migrate due to their random thermal motion. Microscopic particles are jittering around with translational and rotational motions as a result of their thermal energy, which is half the Boltzmann constant multiplied by the absolute temperature of the system (˝kT) per degree of freedom (3 directions of translation and 3 directions of rotation for ordinary particles).
MRI provides a sensitive technique for measuring diffusion of some substances. These diffusive processes mean that particles reach areas of low from areas of high concentration, thus leading to equilibration. In body fluids, the distribution of capillaries within tissues is such that transport over macroscopic distances is accomplished by the blood circulation, while over intercapillary distances substances are carried by diffusion. The fluid diffusion constant is itself inversely proportional to the viscosity and the radius of the diffusing particles.
See also Diffusion Tensor Imaging and Diffusion Weighted Imaging.

spacer

• View the DATABASE results for 'Diffusion' (51).Open this link in a new window


• View the NEWS results for 'Diffusion' (12).Open this link in a new window.
 
Further Reading:
  Basics:
Conventional MRI and MR Angiography of Stroke
2012   by www.mc.vanderbilt.edu    
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
Diffusion-Weighted MRI in the Body: Applications and Challenges in Oncology
Friday, 1 June 2007   by www.ajronline.org    
  News & More:
EORTC study aims to qualify ADC as predictive imaging biomarker in preoperative regimens
Monday, 4 January 2016   by www.eurekalert.org    
Functional imaging with diffusion-weighted MRI for lung biopsy planning: initial experience
Thursday, 10 July 2014   by 7thspace.com    
Diffusion-weighted MRI sensitive for metastasis in pelvic lymph nodes
Sunday, 15 June 2014   by www.2minutemedicine.com    
Connecting the dots: Water diffusion MRI reveals plasticity networks in remote nonstimulated brain regions
Monday, 31 March 2014   by medicalxpress.com    
MRI Resources 
MRI Physics - Sequences - Jobs pool - Safety Products - Spine MRI - Libraries
 
Diffusion Weighted SequenceInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Diffusion Weighted Imaging -
 
Diffusion weighted imaging can be performed similar to the phase contrast angiography sequence. The gradients must be increased in amplitude to depict the much slower motions of molecular diffusion in the body.
While a T1 weighted MRI pulse sequence is diffusion sensitive, a quantitative diffusion pulse sequence was introduced by Steijskal and Tanner. Its characteristic features are two strong symmetrical gradient lobes placed on either side of the 180° refocusing pulse in a spin echo sequence. These symmetrical gradient lobes have the sole purpose of enhancing dephasing of spins, thereby accelerating intravoxel incoherent motion (IVIM) signal loss.
Dephasing is proportional to the square of the time (diffusion time) during which the gradients are switched on and the strength of the applied gradient field. Therefore, the use of high field gradient systems with faster and more sensitive sequences, make diffusion weighting more feasible.
Areas in which the protons diffuse rapidly (swollen cells in early stroke, less restriction to diffusion) will show an increased signal when the echo is measured relative to areas in which diffusion is restricted. For increased accuracy of diffusion measurement and image enhancement, useful motion correction techniques such as navigator echo and other methods should be used. In addition to this, applying the b-value calculated by the strength and duration of motion probing gradients with a high rate of accuracy is very important.
See also Apparent Diffusion Coefficient, ADC Map, Lattice Index Map.

spacer

• View the DATABASE results for 'Diffusion Weighted Sequence' (6).Open this link in a new window

 
Further Reading:
  Basics:
Diffusion-Weighted Imaging
   by spinwarp.ucsd.edu    
Diffusion Imaging: From Basic Physics to Practical Imaging
1999   by ej.rsna.org    
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
  News & More:
Functional imaging with diffusion-weighted MRI for lung biopsy planning: initial experience
Thursday, 10 July 2014   by 7thspace.com    
Diffusion-weighted MRI sensitive for metastasis in pelvic lymph nodes
Sunday, 15 June 2014   by www.2minutemedicine.com    
Hopkins researchers use diffusion MRI technique to monitor ultrasound uterine fibroid treatment
Monday, 8 August 2005   by www.eurekalert.org    
DWI Best in Subacute Stroke Imaging
Tuesday, 1 June 2004   by www.hospimedica.com    
MRI Resources 
Claustrophobia - Implant and Prosthesis - DICOM - Equipment - Crystallography - Guidance
 
     1 - 5 (of 14)     next
Result Pages : [1]  [2 3]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

MR-TIP    
Community   
User
Pass
Forgot your UserID/Password ?  



Your MRI scanner(s) in 5 years should be :
more automated 
much quicker 
quiet 
voice controlled 
iPhone compatible 
as it is right now 

Look
      Ups





Magnetic Resonance - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • US-TIP • The-Medical-Market
Copyright © 2003 - 2016 SoftWays. All rights reserved. [ 24 February 2017]
Terms of Use | Privacy Policy | Advertising
 [last update: 2017-02-21 00:45:00]