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

Out-
      side
 



 
 'sequence' 
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 'sequence' found in 30 terms [] and 347 definitions []
previous     96 - 100 (of 377)     next
Result Pages : [1 2 3 4 5 6]  [7 8 9 10 11 12 13 14 15 16 17 18 19 20 ... ]
Searchterm 'sequence' was also found in the following services: 
spacer
News  (28)  Resources  (10)  Forum  (106)  
 
Cervical Spine MRI
 
Cervical spine MRI is a suitable tool in the assessment of all cervical spine (vertebrae C1 - C7) segments (computed tomography (CT) images may be unsatisfactory close to the thoracic spine due to shoulder artifacts). The cervical spine is particularly susceptible to degenerative problems caused by the complex anatomy and its large range of motion.
Advantages of magnetic resonance imaging MRI are the high soft tissue contrast (particularly important in diagnostics of the spinal cord), the ability to display the entire spine in sagittal views and the capacity of 3D visualization. Magnetic resonance myelography is a useful supplement to conventional MRI examinations in the investigation of cervical stenosis. Myelographic sequences result in MR images with high contrast that are similar in appearance to conventional myelograms. Additionally, open MRI studies provide the possibility of weight-bearing MRI scan to evaluate structural positional and kinetic changes of the cervical spine.
Indications of cervical spine MRI scans include the assessment of soft disc herniations, suspicion of disc hernia recurrence after operation, cervical spondylosis, osteophytes, joint arthrosis, spinal canal lesions (tumors, multiple sclerosis, etc.), bone diseases (infection, inflammation, tumoral infiltration) and paravertebral spaces.
State-of-the-art phased array spine coils and high performance MRI machines provide high image quality and short scan time. Imaging protocols for the cervical spine includes sagittal T1 weighted and T2 weighted sequences with 3-4 mm slice thickness and axial slices; usually contiguous from C2 through T1. Additionally, T2 fat suppressed and T1 post contrast images are often useful in spine imaging.

See also Lumbar Spine MRI.
spacer
 
• Related Searches:
    • MRI Safety
    • Lumbar Spine MRI
    • MRI Scan
    • Medical Imaging
    • Spine MRI
 
Further Reading:
  News & More:
Ultrafast MRI protocol reduces scan time by 10 minutes for cervical imaging
Monday, 26 September 2022   by healthimaging.com    
In Vivo 3-D Cervical Spine Kinematics Demonstrated
Thursday, 19 May 2011   by www.doctorslounge.com    
MRI Images at a 45-Degree Angle Through The Cervic al Neural Forami na:A Technique For Improved Visualization(.pdf)
2006   by www.painphysicianjournal.com    
MRI Resources 
Nerve Stimulator - Artifacts - Guidance - Used and Refurbished MRI Equipment - General - MR Guided Interventions
 
Chemical Shift ArtifactInfoSheet: - Artifacts - 
Case Studies, 
Reduction Index, 
etc.MRI Resource Directory:
 - Artifacts -
 
Quick Overview
Please note that there are different common names for this artifact.
Artifact Information
NAME
Chemical shift, black boundary, spatial misregistration, relief
DESCRIPTION
Black or bright band
During frequency encoding, fat protons precess slower than water protons in the same slice because of their magnetic shielding. Through the difference in resonance frequency between water and fat, protons at the same location are misregistrated (dislocated) by the Fourier transformation, when converting MRI signals from frequency to spatial domain. This chemical shift misregistration cause accentuation of any fat-water interfaces along the frequency axis and may be mistaken for pathology. Where fat and water are in the same location, this artifact can be seen as a bright or dark band at the edge of the anatomy.
Protons in fat and water molecules are separated by a chemical shift of about 3.5 ppm. The actual shift in Hertz (Hz) depends on the magnetic field strength of the magnet being used. Higher field strength increases the misregistration, while in contrast a higher gradient strength has a positive effect. For a 0.3 T system operating at 12.8 MHz the shift will be 44.8 Hz compared with a 223.6 Hz shift for a 1.5 T system operating at 63.9 MHz.
mri safety guidance
Image Guidance
For artifact reduction helps a smaller water fat shift (higher bandwidth), a higher matrix, an in phase TE or a spin echo technique. Since the misregistration offset is present in the read out axis the patient may be rescanned with this axis parallel to the fat-water interface. Steeper gradient may be employed to reduce the chemical shift offset in mm. Another strategy is to employ specialized pulse sequences such as fat saturation or inversion recovery imaging. Fat suppression techniques eliminate chemical shift artifacts caused by the lack of fat signal.

See also Black Boundary Artifact and Magnetic Resonance Spectroscopy.
spacer

• View the DATABASE results for 'Chemical Shift Artifact' (7).Open this link in a new window

 
Further Reading:
  Basics:
MRI Artifact Gallery
   by chickscope.beckman.uiuc.edu    
  News & More:
What is chemical shift artefact? Why does it occur? How many Hz at 1.5 T?
   by www.revisemri.com    
Abdominal MRI at 3.0 T: The Basics Revisited
Wednesday, 20 July 2005   by www.ajronline.org    
MRI Resources 
Chemistry - Breast MRI - Bioinformatics - Implant and Prosthesis pool - Devices - Musculoskeletal and Joint MRI
 
Completely Balanced Steady StateInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
(CBASS) A gradient echo sequence with balanced waveform.

See Steady State Free Precession and Balanced Sequence.
spacer

• View the DATABASE results for 'Completely Balanced Steady State' (2).Open this link in a new window

Searchterm 'sequence' was also found in the following services: 
spacer
News  (28)  Resources  (10)  Forum  (106)  
 
Contrast Enhanced FASTInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.MRI Resource Directory:
 - Sequences -
 
(CE-FAST) In this technique, the MR signal is sampled immediately prior to each RF pulse. Because the signal is formed by a true spin echo, its contrast is predominantly T2-, rather than T2*-based and is less sensitive to artifacts and signal losses related to field non-uniformity and susceptibility variation. While the signal to noise ratio is limited, the CE-FAST method has the advantage of good contrast.

See Contrast Enhanced Gradient Echo Sequence and Gradient Echo Sequence.
spacer

• View the DATABASE results for 'Contrast Enhanced FAST' (5).Open this link in a new window

MRI Resources 
Distributors - Examinations - MR Guided Interventions - Developers - MRI Accidents - Artifacts
 
Contrast Enhanced FLASHInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(CE FLASH) A fast T2 weighted imaging sequence utilizing refocused transverse coherence.

See Contrast Enhanced Echo Sequence.
spacer
MRI Resources 
Societies - Movies - Collections - MRI Training Courses - NMR - Mass Spectrometry
 
previous      96 - 100 (of 377)     next
Result Pages : [1 2 3 4 5 6]  [7 8 9 10 11 12 13 14 15 16 17 18 19 20 ... ]
 Random Page
 
Share This Page
FacebookTwitterLinkedIn

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



New acceleration techniques will :
reduce scan times 
cause artifacts 
increase expenses 
be useful if you have a lot of experience 
doesn't do much 
never heard of 

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 • Medical-Ultrasound-Imaging • 
Copyright © 2003 - 2024 SoftWays. All rights reserved. [ 4 December 2024]
Terms of Use | Privacy Policy | Advertising
 [last update: 2024-02-26 03:41:00]