TECHNIQUE FOR SHARING VIEWS FOR QMAP TO REDUCE ACQUISITION TIME OF MAGNETIC RESONANCE (MR) IMAGES
Publication Date: 2016-Jul-01
The IP.com Prior Art Database
A technique for view sharing for multi-echo on Fast Spin Echo (FSE) is proposed. Views are shared between echoes with different echo time (TE) as well as between echoes with different delay times. The views are shared from T2 acquisition to proton density (PD) acquisition and the shared high frequency views are required to be symmetrical about k-space center. The technique reduces scanning time for Qmap.
The present disclosure relates generally to magnetic resonance (MR) imaging and more particularly to a technique for sharing views for Qmap to reduce acquisition time of MR images.
Generally, diagnosis of an anomaly or pathology in imaged anatomy relies on comparison with surrounding assumingly normal tissue in the image. Therefore, in many instances, several different contrast scans using synthetic magnetic resonance (MR) are performed. A more direct approach is absolute quantification of tissue parameters such as longitude T1 relaxations, transverse T2 relaxation, and proton density (PD). Further, Qmap is 2D Fast Spin Echo (FSE) based pulse sequence which enables quantification parameters to be measured in one single scan by means of a multi-slice, multi-echo, and multi-delay acquisition. The images obtained by Qmap is input of software Synthetic MR, which offers new magnetic resonance image processing methodology for tissue quantification and also for generating multiple contrast images with a single scan.
In conventional techniques, 4 saturation delay and 2 echo time are used. For example, in brain scans, total acquisition time for a typically protocol setting with a field of view (FOV) of 24cm, echo train length (ETL) =12 and 256*256 resolutions works out to be about 6 minutes in a 1.5T scanner. If resolution of acquired images is to be increased, scanning time becomes far out of clinically acceptable range. Excessive scan time is the major hurdle for the Qmap technique, which has impeded its widespread clinical application. Long scan time increases possibility of introducing moving artifact, which has adversely impacts image quality of the Synthetic MR results.
One conventional technique describes a scheme for view sharing with multiple images acquired in fast spin echo. Low-order phase encoding data is acquired separately for each image and common high-order phase encoding data is used for all the images. An equal number of signals for the views are acquired for the two differently weighted images. Another conventional technique provides a similar method of view sharing scheme, but involves acquiring fewer low-order views for the PD image than low-order views for T2 image. This avoids the use of highly T2-weighted signals for PD images to reduce edge oscillation artifacts in PD image. However, conventional techniques share only high-order views between PD images and T2 images.
It would be desirable to have an improved technique for sharing views for Qmap to reduce acquisition time of MR images.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts an example of proposed view-sharing technique for duel-echo using an echo train length of 12.
Figure 2 depicts the view sharing technique described herein for Qmap.
Figure 3 is a table of the level of view sharing with corresponding scan time, levels of time reduction and ghost level us...