Reduction of signal fluctuation in functional MRI using navigator echoes
- 1 May 1994
- journal article
- research article
- Published by Wiley in Magnetic Resonance in Medicine
- Vol. 31 (5) , 495-503
- https://doi.org/10.1002/mrm.1910310505
Abstract
Functional magnetic resonance imaging is sensitive to signal fluctuations due to physiological motion and system instability. In this paper, motion‐related signal fluctuations are studied, and a method that uses navigator echoes to monitor and compensate for signal fluctuations in a gradient‐echo sequence is described. The technique acquires a “navigator” signal before the application of the phase‐encoding and readout gradients and corrects the phase of the subsequently acquired imaging data. This technique was implemented on a 4 Tesla whole body system and validated on normal volunteers. With this technique, temporal fluctuations in image intensity were substantially reduced and improved functional activation maps were obtained.Keywords
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