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


Out-
      side
 

Your new MRI scanner in 2020 will be shipped from :
China 
Europe 
India 
Japan 
USA 
other 




 
MRI Artifacts
  
Ultrasound Imaging Artifacts Open this link in a new window
Flow Artifact 
Quick Overview
Please note that there are different common names for this artifact.

Artifact Information
NAME Spin phase effect, flow
DESCRIPTION Vascular ghosts (ghosting artifact), anomalous intensities in images
REASON Movement of body fluids
HELP Flow compensation, presaturation, triggering

Flow effects in MRI produce a range of artifacts, e.g. intravascular signal void by time of flight effects; turbulent dephasing and first echo dephasing, caused by flowing blood.
Through movement of the hydrogen nuclei (e.g. blood flow), there is a location change between the time these nuclei experience a radio frequency pulse and the time the emitted signal is received (because the repetition time is asynchronous with the pulsatile flow).
The blood flow occasionally produces intravascular high signal intensities due to flow related enhancement, even echo rephasing and diastolic pseudogating. The pulsatile laminar flow within vessels often produces a complex multilayered band that usually propagates outside the head in the phase encoded direction. Blood flow artifacts should be considered as a special subgroup of motion artifacts.


Image Guidance
Artifacts can be reduced by reduction of phase shifts with flow compensation (gradient moment nulling), suppression of the blood signal with saturation pulses parallel to the slices, synchronization of the imaging sequence with the heart cycle (cardiac triggering) or can be flipped 90° by swapping the phase//frequency encoding directions.
See also Flow Related Enhancement and Flow Effects.

• View the DATABASE results for 'Flow Artifact' (6).Open this link in a new window

 
Further Reading:
  News & More:
MRI measure of blood flow over atherosclerotic plaque may detect dangerous plaque
Friday, 5 April 2013   by www.sciencecodex.com    
Advanced Visualization Techniques Could Change the Paradigm for Diagnosis and Treatment of Heart Disease
Thursday, 31 May 2012   by www.sciencedaily.com    
Case Study 1 :
Flow artifacts from both iliac vessels, seeing as a band of bright points in anterior to posterior direction (phase encoding).
 
Case Study 2 :
Flow artifacts from both femoral vessels, seeing as a shadowed band in anterior to posterior direction (phase encoding).
 
Case Study 3 :
Flow artifact in right to left direction (phase encoding) from the popliteal vessel, seen as a small bright artifact along the middle of the femoral bone.
 
Similar Artifacts:
 • Phase Encoded Motion Artifact
 • Motion Artifact
  Ghosting Artifact top
 
Share This Page
FacebookTwitterLinkedIn

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



Look
      Ups






Magnetic Resonance - Technology Information Portal
Member of SoftWays' Medical Imaging Group - MR-TIP • Radiology-TIP • US-TIP • The-Medical-Market
Copyright © 2003 - 2014 SoftWays. All rights reserved. [ 24 November 2014]
Terms of Use | Privacy Policy | Advertising
 [last update: 2014-11-24 03:47:17]