Table 3. Partial derivatives $\frac{\partial {\text{S}}_{{\text{T}}_1}}{\partial {\text{T}}_1}$, $\frac{\partial {\text{T}}_{\text{1}}}{\partial \text{f}}$, $\frac{\partial \text{f}}{\partial \text{x}}$ and which determine T₁-dependent change in signal (or contrast) with distance at boundaries.

$\frac{\partial {\text{S}}_{{\text{T}}_1}}{\partial {\text{T}}_1}$ †	$\frac{\partial {\text{T}}_1}{\partial \text{f}}$	$\frac{\partial \text{f}}{\partial \text{x}}$
Increasing T1 sequence weighting from lower (first row) to higher (fourth row) (below)	Increasing value from lower (first row) to higher (third row) (below)	Increasing value from lower (first row) to higher (second row) (below)
SGE	White matter-gray matter	Gradual
IR	Gray matter-CSF	Abrupt
SIR	White matter-CSF
dSIR

^†, sequence weighting = slope of T₁-filter. SGE, spoiled gradient echo; IR, inversion recovery; SIR, subtracted inversion recovery; dSIR, divided subtracted inversion recovery; CSF, cerebrospinal fluid.