Abstract
Amide proton transfer (APT) imaging is a new MRI technique that detects endogenous mobile proteins and peptides in tissue via saturation of the amide protons in the peptide bonds. Initial studies have shown promise in detecting tumor and stroke, but this technique was hampered by magnetic field inhomogeneity and a low signal-to-noise ratio. Several important prerequisites for performing APT imaging experiments include designing an effective APT imaging pulse sequence based on the hardware capability, optimizing the experimental protocol for the best clinical imaging quality, and developing data-processing approaches for effective image assessment. In this chapter, technical issues, such as pulse sequence design and optimization, magnetic field inhomogeneity correction, specific absorption rate minimization, and scan duration, are addressed.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsSpringer Nature is developing a new tool to find and evaluate Protocols. Learn more
References
Wolff, S. D., Balaban, R. S. Magnetization transfer contrast (MTC) and tissue water proton relaxation in vivo. Magn Reson Med 1989;10:135–144.
Henkelman, R. M., Stanisz, G. J., Graham, S. J. Magnetization transfer in MRI: A review. NMR Biomed 2001;14:57–64.
Zhou, J., Payen, J., Wilson, D. A., Traystman, R. J., van Zijl, P. C. M. Using the amide proton signals of intracellular proteins and peptides to detect pH effects in MRI. Nat Med 2003;9:1085–1090.
Ward, K. M., Aletras, A. H., Balaban, R. S. A new class of contrast agents for MRI based on proton chemical exchange dependent saturation transfer (CEST). J Magn Reson 2000;143:79–87.
Sun, P. Z., Zhou, J., Sun, W., Huang, J., van Zijl, P. C. M. Delineating the boundary between the ischemic penumbra and regions of oligaemia using pH-weighted magnetic resonance imaging (pHWI). J Cereb Blood Flow Metab 2007;27:1129–1136.
Jokivarsi, K. T., Grohn, H. I., Grohn, O. H., Kauppinen, R. A. Proton transfer ratio, lactate, and intracellular pH in acute cerebral ischemia. Magn Reson Med 2007;57:647–653.
Zhou, J., Lal, B., Wilson, D. A., Laterra, J., van Zijl, P. C. M. Amide proton transfer (APT) contrast for imaging of brain tumors. Magn Reson Med 2003;50:1120–1126.
Jones, C. K., Schlosser, M. J., van Zijl, P. C., Pomper, M. G., Golay, X., Zhou, J. Amide proton transfer imaging of human brain tumors at 3T. Magn Reson Med 2006;56:585–592.
Zhou, J., Blakeley, J. O., Hua, J. et al. Practical data acquisition method for human brain tumor amide proton transfer (APT) imaging. Magn Reson Med 2008;60:842–849.
Hobbs, S. K., Shi, G., Homer, R., Harsh, G., Altlas, S. W., Bednarski, M. D. Magnetic resonance imaging-guided proteomics of human glioblastoma multiforme. J Magn Reson Imaging 2003;18:530–536.
Howe, F. A., Barton, S. J., Cudlip, S. A. et al. Metabolic profiles of human brain tumors using quantitative in vivo 1H magnetic resonance spectroscopy. Magn Reson Med 2003;49:223–232.
Goffeney, N., Bulte, J. W. M., Duyn, J., Bryant, L. H., van Zijl, P. C. M. Sensitive NMR detection of cationic-polymer-based gene delivery systems using saturation transfer via proton exchange. J Am Chem Soc 2001;123:8628–8629.
McMahon, M. T., Gilad, A. A., Zhou, J., Sun, P. Z., Bulte, J. W. M., van Zijl, P. C. M. Quantifying exchange rates in chemical exchange saturation transfer agents using the saturation time and saturation power dependencies of the magnetization transfer effect on the magnetic resonance imaging signal (QUEST and QUESP): pH calibration for poly-L-lysine and a starburst dendrimer. Magn Reson Med 2006;55:836–847.
Bryant, R. G. The dynamics of water-protein interactions. Annu Rev Biophys Biomol Struct 1996;25:29–53.
Kim, M., Gillen, J., Landman, B. A., Zhou, J., van Zijl, P. C. M. Water saturation shift referencing (WASSR) for chemical exchange saturation transfer (CEST) experiments. Magn Reson Med 2009;61:1441–1450.
Acknowledgments
The author thanks the team at the F.M. Kirby Research Center for Functional Brain Imaging for helpful discussions and technical assistance. This work was supported in part by grants from NIH (EB002634, EB005252, EB009112, EB009731, and RR015241) and the Dana Foundation.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2011 Springer Science+Business Media, LLC
About this protocol
Cite this protocol
Zhou, J. (2011). Amide Proton Transfer Imaging of the Human Brain. In: Modo, M., Bulte, J. (eds) Magnetic Resonance Neuroimaging. Methods in Molecular Biology, vol 711. Humana Press. https://doi.org/10.1007/978-1-61737-992-5_10
Download citation
DOI: https://doi.org/10.1007/978-1-61737-992-5_10
Published:
Publisher Name: Humana Press
Print ISBN: 978-1-61737-991-8
Online ISBN: 978-1-61737-992-5
eBook Packages: Springer Protocols