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


Out-
      side
 



 
 'Signal Intensity' 
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 'Signal Intensity' found in 1 term [] and 55 definitions []
previous     26 - 30 (of 56)     next
Result Pages : [1]  [2 3 4 5 6 7 8 9 10 11 12]
Searchterm 'Signal Intensity' was also found in the following services: 
spacer
News  (5)  Resources  (1)  Forum  (4)  
 
FlowForum -
related threads
 
Flow phenomena are intrinsic processes in the human body. Organs like the heart, the brain or the kidneys need large amounts of blood and the blood flow varies depending on their degree of activity. Magnetic resonance imaging has a high sensitivity to flow and offers accurate, reproducible, and noninvasive methods for the quantification of flow. MRI flow measurements yield information of blood supply of of various vessels and tissues as well as cerebro spinal fluid movement.
Flow can be measured and visualized with different pulse sequences (e.g. phase contrast sequence, cine sequence, time of flight angiography) or contrast enhanced MRI methods (e.g. perfusion imaging, arterial spin labeling).
The blood volume per time (flow) is measured in: cm3/s or ml/min. The blood flow-velocity decreases gradually dependent on the vessel diameter, from approximately 50 cm per second in arteries with a diameter of around 6 mm like the carotids, to 0.3 cm per second in the small arterioles.

Different flow types in human body:
Behaves like stationary tissue, the signal intensity depends on T1, T2 and PD = Stagnant flow
Flow with consistent velocities across a vessel = Laminar flow
Laminar flow passes through a stricture or stenosis (in the center fast flow, near the walls the flow spirals) = Vortex flow
Flow at different velocities that fluctuates = Turbulent flow

See also Flow Effects, Flow Artifact, Flow Quantification, Flow Related Enhancement, Flow Encoding, Flow Void, Cerebro Spinal Fluid Pulsation Artifact, Cardiovascular Imaging and Cardiac MRI.
 
Images, Movies, Sliders:
 MVP Parasternal  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 TOF-MRA Circle of Willis Inverted MIP  Open this link in a new window
    

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

 
spacer
 
• Related Searches:
    • Signal Intensity
    • Blood Flow-Velocity
    • Brain MRI
    • Inflow Magnetic Resonance Angiography
    • Velocity
Searchterm 'Signal Intensity' was also found in the following service: 
spacer
Radiology  (1) Open this link in a new window
Gadolinium OxideInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
Gadolinium oxide (Gd2O3) is a prototype paramagnetic agent for contrast enhanced MRI. Gd2O3 particles have very high relaxivity. With its high magnetic moment, gadolinium reduces the relaxation time and enhance MR signal intensity. All gadolinium compounds are highly toxic. Very stable complexes are developed to eliminate the toxicity. See also Paramagnetic Substance, Paramagnetism, Paramagnetic Contrast Agents and Contrast Agents, the info sheet gives an overview and more in-dept information about different types of MRI Contrast media.
spacer

• View the DATABASE results for 'Gadolinium Oxide' (2).Open this link in a new window

 
Further Reading:
  Basics:
Gadolinium oxide nanoparticles enhance MRI contrast
Thursday, 29 September 2011   by nanotechweb.org    
  News & More:
Northern Rare Earth eyes medical device prospects
Thursday, 29 December 2016   by usa.chinadaily.com.cn    
MRI Resources 
Most Wanted - MRI Physics - Spine MRI - Mobile MRI - Safety Products - Blood Flow Imaging
 
GadoversetamideInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.
 
Short name: Gd-DTPA-BMEA, generic name: Gadoversetamide
A paramagnetic extracellular MRI contrast agent with positive enhancement. When placed in a magnetic field, gadoversetamide decreases T1 and T2 relaxation times in tissues where it accumulates. At the recommended dose, the effect is primarily on T1 relaxation time, and produces an increase in signal intensity (brightness).
See Contrast Agents and OptiMARK™.

spacer

• View the DATABASE results for 'Gadoversetamide' (3).Open this link in a new window


• View the NEWS results for 'Gadoversetamide' (1).Open this link in a new window.
 
Further Reading:
  Basics:
OptiMARK® (gadoversetamide injection)
  News & More:
MAGNETIC RESONANCE IMAGING OF FOCAL LIVER LESIONS(.pdf)
2002
PRAC concludes assessment of gadolinium agents used in body scans and recommends regulatory actions, including suspension for some marketing authorisations
Friday, 10 March 2017   by www.satprnews.com    
Searchterm 'Signal Intensity' was also found in the following services: 
spacer
News  (5)  Resources  (1)  Forum  (4)  
 
Gastrointestinal Paramagnetic Contrast AgentsInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Agents -
 
Paramagnetic substances, for example Gd-DTPA solutions, are used as MRI oral contrast agents in gastrointestinal imaging to depict the lumen of the digestive organs. Different Gd-DTPA solutions or zeolites containing gadolinium can be used e.g., for diagnosis of delayed gastric emptying, diagnosis of Crohn's disease etc.
Low concentrations of gastrointestinal paramagnetic contrast agents cause a reduction in T1 relaxation time; consequently, these agents act on T1 weighted images by increasing the signal intensity of the bowel lumen. High concentrations cause T2 shortening by decreasing the signal, similar to superparamagnetic iron oxide. Gd-DTPA chelates are unstable at the low pH in the stomach, therefore buffering is necessary for oral use.
See also Gadopentetate Gastrointestinal, Gadolinium Zeolite, Negative Oral Contrast Agents, Gastrointestinal Superparamagnetic Contrast Agents, and Ferric ammonium citrate.
 
Images, Movies, Sliders:
 MR Colonography Gadolinium per Rectum  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 
spacer

• View the DATABASE results for 'Gastrointestinal Paramagnetic Contrast Agents' (5).Open this link in a new window

Searchterm 'Signal Intensity' was also found in the following service: 
spacer
Radiology  (1) Open this link in a new window
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:
 CE-MRA of the Carotid Arteries Colored MIP  Open this link in a new window
    
SlidersSliders Overview

 Anatomic Imaging of the Lumbar Spine  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 Normal Dual Inversion Fast Spin-echo  Open this link in a new window
      

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
spacer
Radiology-tip.comUltrasound Imaging,  Ultrasound Imaging Procedures
spacer

• 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 
Process Analysis - Sequences - Liver Imaging - Supplies - Movies - Calculation
 
previous      26 - 30 (of 56)     next
Result Pages : [1]  [2 3 4 5 6 7 8 9 10 11 12]
 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





MR-TIP.com uses cookies! By browsing MR-TIP.com, you agree to our use of cookies.

Magnetic Resonance - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • US-TIP • 
Copyright © 2003 - 2018 SoftWays. All rights reserved. [ 22 January 2019]
Terms of Use | Privacy Policy | Advertising
 [last update: 2018-03-08 05:11:00]