Purpose To explore the relationship of APT and NOE signal intensities with respect to different World Health Organization (WHO) brain tumor grades (II to IV) at 7T. Materials and Methods APT-based and NOE-based signals at 7T using low-power steady-state CEST were compared among de novo primary gliomas of different WHO grades (II to IV). The quantitative APT and NOE signals, calculated by fitting approach using extrapolated semi-solid MT reference (EMR) signals, were compared with the magnetization transfer ratio asymmetry (MTRasym) analysis, commonly used in APT-weighted MRI. Results The observed NOE signals of all glioma grades were significantly lower than normal brain tissue (p < 0.01). NOE signals significantly differed between low-grade (II) gliomas and high-grade (III & IV) gliomas (p < 0.05). APT signals showed no difference between the tumor regions for any glioma grades (M = 3.08 %, 2.64 %, and 3.10 %, 95% CI = 2.81 % ~ 3.33 %, 2.36 % ~ 2.91 %, and 2.85 % ~ 3.36 % for grade II, III, and IV, respectively), and between normal brain tissue and all glioma grades (p = 0.08, M = 4.29 % and 2.94 %, 95% CI = 3.57 % ~ 4.99 % and 2.47 % ~ 3.41 % for normal and average grade II, III, and IV), while MTRasym differed significantly between normal tissue and all glioma grades (p < 0.05). Conclusion NOE contributes substantially to APT weighted MRI at 7T at low RF saturation power and provides a promising biomarker for glioma grading.

Overall there is moderate group level rs-vs-task fMRI language network concordance, however substantial subject-level variability exists; iRMS may be used to determine reliability of rs-fMRI derived language networks.

We conclude that white matter tracts from both the somatosensory and the motor cortex play an important role in the pathophysiology of motor disability in patients with CP.