Table 5. A synoptic table of main findings in this study.

Metrics	Model	Potential pathophysiological implications	Correlation with tumor grade	Correlation with IDH1 mutation status	Value in diagnosis
ALPS-index	DTI	Potentially correlated with the function of the glymphatic system	Gliomas can lead to decrease in the ALPS-index, and patients with GBMs have a lower ALPS-index than do patients with LrGGs	Patients with IDH1-wild-type gliomas have a lower ALPS-index than do patients with IDH1 mutant gliomas	The ALPS-index could improve the diagnostic ability when added to other conventional diffusion metrics
FA		The measurement of the directionality of molecular motion, which can reflect the white matter integrity in brain	GBMs have a higher FA than do LrGGs	IDH1-wild-type gliomas have a higher FA	These conventional DTI- and DKI-derived metrics have been used in glioma grading and IDH1 genotyping
MD		The rate of water molecules’ diffusional motion, which correlates with tumor cellularity	GBMs have a lower MD than do LrGGs	IDH1-wild-type gliomas have a lower MD
MK	DKI	Can provide the kurtosis of water diffusion under non-Gaussian distribution in an organism	GBMs have a higher MK than do LrGGs	IDH1-wild-type gliomas have a higher MK

IDH1, isocitrate dehydrogenase 1; ALPS, analysis along the perivascular space; FA, fractional anisotropy; MD, mean diffusivity; MK, mean kurtosis; DTI, diffusion tensor imaging; DKI, diffusion kurtosis imaging; LrGG, lower-grade glioma; GBM, glioblastoma.