NetForum uses cookies to ensure that we give you the best experience on our website. If you continue to use the site, we'll assume that you are happy to receive these cookies on the NetForum website. Read about our cookies.
NetForum Community
Learn. Share. Optimize.
Log in | Sign up now | Submit content | Contact
Go to similar content

MultiVane k-space sampling method corrects for motion

White Paper
Welch, Brian Philips Healthcare

MultiVane employs an in-plane motion correction strategy that uses a novel MR signal sampling trajectory in k-space.


"MultiVane is a non-cartesian technique that oversamples the centers of k-space using separate cartesian vanes," says VUIIS-based Philips clinical scientist Brian Welch, who worked on MultiVane implementation. "Each vane contains k-space samples corresponding to the same low resolution image. If in-plane motion occurs, the low resolution images will move vane-to-vane.

 

Registering the low resolution images from each vane allows detection of in-plane motion - such as nodding or shaking the head - and correction of the individual vanes," Dr. Welch continues. "MultiVane is particularly well-designed because an individual vane is a Cartesian data set, which enables easier correction than with radial or spiral sampling schemes that are vulnerable to phase differences and off-resonance effects. All vanes are ultimately combined to create a single high resolution image that is sharp and artifact-free. If the low resolution image from a specific vane correlates poorly with other vanes, it is eliminated or underweighted during reconstruction."

 

Graphic depiction of MultiVane k-space data acquisition.

Data are acquired in a series of rotating vanes (single vane

is shaded), each of which collects data from a central area

of k-space. Each vane contains several phaseencoding lines.

 

 

MR protocols that collect many k-space lines in multiple snapshots, such as TSE or TFE, are best suited for MultiVane, because each vane can then be a quick snapshot that freezes the subject's motion. However, MultiVane can be combined with any sequence that is normally collected by a Cartesian trajectory, he explains.

 

 

Without MultiVane With MultiVane
Without MultiVane
With MultiVane

 

MultiVane is a strong competitor to other Cartesian motion correction strategies in its robust motion correction. If motion is occurring, Cartesian images will contain artifacts (primarly ghosts) that cannot be removed except through time-consuming iterative techniques or with the aid of fiducial markers or navigator echoes that must be acquired in addition to imaging to provide information about the motion. Furthermore, any residual motion inconsistencies in a MultiVane reconstruction will result in slight blurring, instead of distinct ghosts that may diminish the diagnostic utility of the images.

 

"MultiVane is elegant because the imaging data itself acts as a '2D navigator' - that is, the low resolution images contained within each blade," he observes. "The drawback is that the MultiVane trajectory is somewhat longer than the Cartesian equivalent. However, the literature shows that MultiVane can truly provide diagnostic quality images when Cartesian can't."

 

For more on VUIIS (Vanderbilt University Institute of Imaging Science), see:



This content has been made possible by NetForum Community.
Share this on: Share your link in twitter Share your link in facebook Share your link on LinkedIn Print Rate this article: Log in to vote

 
Rating:
Votes:
2
Views:
7167
Added:
Sep 4, 2007

Rate this:
Log in to vote
 

White Paper
Brain, MultiVane, Neuro
 

Clinical News
Best Practices
Case Studies
Publications and Abstracts
White Papers
Web seminars and Presentations
ExamCards
Protocols
Application Tips and FAQ
Training
Try an Application
Business News
Case Studies
White Papers
Web Seminars and Presentations
Utilization Services
Contributing Professionals
Contributing Institutions
Become a Contributor