Review: MR Physics for Clinicians
Gradient echo imaging
Article first published online: 15 MAY 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging
Volume 35, Issue 6, pages 1274–1289, June 2012
How to Cite
Markl, M. and Leupold, J. (2012), Gradient echo imaging. J. Magn. Reson. Imaging, 35: 1274–1289. doi: 10.1002/jmri.23638
- Issue published online: 14 MAY 2012
- Article first published online: 15 MAY 2012
- Manuscript Accepted: 15 FEB 2012
- Manuscript Received: 31 AUG 2011
- gradient echo;
- balanced SSFP;
- steady state free precession;
Magnetic resonance imaging (MRI) based on gradient echoes is used in a wide variety of imaging techniques and clinical applications. Gradient echo sequences form the basis for an essential group of imaging methods that find widespread use in clinical practice, particularly when fast imaging is important, as for example in cardiac MRI or contrast-enhanced MR angiography. However, the term “gradient echo sequence” is somewhat unspecific, as even images acquired with the most common sequences employing the gradient echo for data acquisition can significantly differ in signal, contrast, artifact behavior, and sensitivity to, eg, flow. This is due to the different use of sequence timing and basic sequence building blocks such as spoiler gradients or specific radiofrequency (RF) pulse phase patterns. In this article the basic principles of gradient echo formation compared to spin echo imaging are reviewed and the properties of gradient echo imaging in its simplest form (TR ≫ T2) are described. Further, the most common three variants of fast gradient echo sequences (TR < T2), namely, unbalanced gradient echo, RF spoiled gradient echo, and balanced steady state free precession; are discussed. For each gradient echo sequence type, examples of applications exploiting the specific properties of the individual technique are presented. J. Magn. Reson. Imaging 2012;35:1274–1289. © 2012 Wiley Periodicals, Inc.