Prospective motion correction using inductively coupled wireless RF coils
Article first published online: 27 JUN 2013
Copyright © 2013 Wiley Periodicals, Inc.
Magnetic Resonance in Medicine
Volume 70, Issue 3, pages 639–647, September 2013
How to Cite
Ooi, M. B., Aksoy, M., Maclaren, J., Watkins, R. D. and Bammer, R. (2013), Prospective motion correction using inductively coupled wireless RF coils. Magn Reson Med, 70: 639–647. doi: 10.1002/mrm.24845
- Issue published online: 27 AUG 2013
- Article first published online: 27 JUN 2013
- Manuscript Accepted: 24 MAY 2013
- Manuscript Revised: 22 MAY 2013
- Manuscript Received: 18 MAR 2013
- NIH . Grant Numbers: 2R01 EB00271108-A1, 5RO1 EB008706, 5R01 EB01165402-02
- CAMRT at Stanford . Grant Number: P41 EB015891
- Lucas Foundation and Oak Foundation
- prospective real-time motion correction;
- motion tracking;
- wireless marker;
- inductive coupling;
- active marker;
- radio frequency coil
A novel prospective motion correction technique for brain MRI is presented that uses miniature wireless radio-frequency coils, or “wireless markers,” for position tracking.
Each marker is free of traditional cable connections to the scanner. Instead, its signal is wirelessly linked to the MR receiver via inductive coupling with the head coil. Real-time tracking of rigid head motion is performed using a pair of glasses integrated with three wireless markers. A tracking pulse-sequence, combined with knowledge of the markers' unique geometrical arrangement, is used to measure their positions. Tracking data from the glasses is then used to prospectively update the orientation and position of the image-volume so that it follows the motion of the head.
Wireless-marker position measurements were comparable to measurements using traditional wired radio-frequency tracking coils, with the standard deviation of the difference < 0.01 mm over the range of positions measured inside the head coil. Wireless-marker safety was verified with B1 maps and temperature measurements. Prospective motion correction was demonstrated in a 2D spin-echo scan while the subject performed a series of deliberate head rotations.
Prospective motion correction using wireless markers enables high quality images to be acquired even during bulk motions. Wireless markers are small, avoid radio-frequency safety risks from electrical cables, are not hampered by mechanical connections to the scanner, and require minimal setup times. These advantages may help to facilitate adoption in the clinic. Magn Reson Med 70:639–647, 2013. © 2013 Wiley Periodicals, Inc.