Table 2.

Summary of the main tissue properties affecting different MR parameters.

		Tissue properties/bio-physical processes
		Myelin		Iron		Calcium		Free water		Inflammation (glial cell proliferation)		Neuronal density
			References		References		References		References		References		References
MRI parameters	T1	↓	(Rooney et al., 2007, Stüber et al., 2014, Waehnert et al., 2016)	↓	(Stüber et al., 2014)	↓	(Wehrli, 2013)	↑	(Rooney et al., 2007)
	PD	↓	(Neeb et al., 2008)					↑	(Tofts, 2005)
	MT	↑	(Graham and Henkelman, 1999)					↓	(Tofts, 2005)
	R2*	↑	(Tofts, 2005)	↑	(Haacke et al., 2005, Langkammer et al., 2010, Wehrli, 2013, Yao et al., 2009)			↓	(Haacke et al., 2005)
	R2	↑	(Briellmann et al., 2002)	↑	(Whittall et al., 1997)					↓	(Briellmann et al., 2002)
	χ	↓	(Gupta et al., 2001)	↑	(Langkammer et al., 2010, Liu et al., 2011, Yao et al., 2009)	↓	(Schweser et al., 2011)
	FA	↑	(Beppu et al., 2003, Johansen-Berg and Behrens, 2013)							↓	(Werring et al., 1999)
	MD	↓	(Alexander et al., 2012)					↑	(Feldman et al., 2010)
	ICVF	↑	(Jespersen et al., 2010)									↑	(Winston et al., 2014)
	IVF							↑	(Zhang et al., 2012)
	Micro FA	↑	(Kaden et al., 2016a)							↓	(Werring et al., 1999)

The symbol ↑ represents the increase of an MR parameter due to the presence of a specific tissue property/biophysical process; the symbol ↓ stands for an MR parameter decrease. T1: longitudinal relaxation time; PD: proton density; MT: magnetisation transfer; R2*: effective transverse relaxation rate; χ: susceptibility mapping; FA: fractional anisotropy; MD: mean diffusivity; ICVF: intra-cellular volume fraction, IVF: isotropic volume fraction.