Table 2. Results from error propagation calculation for C₁ and α. Column 1 shows the mean values of C₁ and α calculated from the mean values of S₁ (aTSC) and S₂ (aISC) over 5 volunteers and for typical mean values of C₂ (extracellular/CSF sodium concentration) and w (water fraction) in healthy brain tissue. Uncertainties (standard deviations - std) in the estimation of C₁ and α were calculated for typical and extreme variations of C₂ and w, and for std of S₁ and S₂ over 5 volunteers (considered as typical values). Columns 2 and 3 show the resulting std of C₁ and α when the variations of all 4 parameters are taken into account, for typical and extreme std of C₂ and w, respectively. Columns 4 to 9 show the effect of individual (typical and extreme) variations of S₁, S₂, C₂ or w on the uncertainties of C₁ and α. All std results for C₁ and α are given in absolute value (and percentage).

Column		1	2	3	4	5	6	7	8	9
Variation type			Typical	Extreme	Typical	Typical	Typical	Extreme	Typical	Extreme
	Units	Mean	Std	Std	Std	Std	Std	Std	Std	Std
S1	mM	35	8	8	8
S2	mM	8	3	3		3
C2	mM	140	5	10			5	10
w		0.8	0.05	0.10					0.05	0.10
C1	mM	13	4.8 (36%)	5.1 (39%)	1.2 (9%)	4.5 (34%)	0.15 (1%)	0.3 (2%)	1.1 (8%)	2.2 (16%)
α		0.2	0.061 (32%)	0.063 (32%)	0.060 (30%)	0.021 (11%)	0.007 (4%)	0.014 (7%)	0	0