Premium
Quantitative assessment of amide proton transfer (APT) and nuclear overhauser enhancement (NOE) imaging with extrapolated semisolid magnetization transfer reference (EMR) signals: II. Comparison of three EMR models and application to human brain glioma at 3 Tesla
Author(s) -
Heo HyeYoung,
Zhang Yi,
Jiang Shanshan,
Lee DongHoon,
Zhou Jinyuan
Publication year - 2016
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25795
Subject(s) - magnetization transfer , nuclear magnetic resonance , chemistry , flip angle , magnetization , nuclear overhauser effect , human brain , nuclear medicine , glioma , magnetic resonance imaging , nuclear magnetic resonance spectroscopy , physics , medicine , radiology , magnetic field , quantum mechanics , cancer research , psychiatry
Purpose To evaluate the use of three extrapolated semisolid magnetization transfer reference (EMR) methods to quantify amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) signals in human glioma. Methods Eleven patients with high‐grade glioma were scanned at 3 Tesla. aEMR 2 (asymmetric magnetization‐transfer or MT model to fit two‐sided, wide‐offset data), sEMR 2 (symmetric MT model to fit two‐sided, wide‐offset data), and sEMR 1 (symmetric MT model to fit one‐sided, wide‐offset data) were assessed. Z EMR and experimental data at 3.5 ppm and −3.5 ppm were subtracted to calculate the APT and NOE signals (APT # and NOE # ), respectively. Results The aEMR 2 and sEMR 1 models provided quite similar APT # signals, while the sEMR 2 provided somewhat lower APT # signals. The aEMR 2 had an erroneous NOE # quantification. Calculated APT # signal intensities of glioma (∼4%), much larger than the values reported previously, were significantly higher than those of edema and normal tissue. Compared with normal tissue, gadolinium‐enhancing tumor cores were consistently hyperintense on the APT # maps and slightly hypointense on the NOE # maps. Conclusion The sEMR 1 model is the best choice for accurately quantifying APT and NOE signals. The APT‐weighted hyperintensity in the tumor was dominated by the APT effect, and the MT asymmetry at 3.5 ppm is a reliable and valid metric for APT imaging of gliomas at 3T. Magn Reson Med 75:1630–1639, 2016. © 2015 Wiley Periodicals, Inc.