Table 2.

Definition of the MR Parameters

Parameter		Description
DWI
		IVIM S(b) = S0(1 − f ) ∙ e−bD + S0f ∙ e−b(D + D∗) S0: signal without diffusion weighting Model parameters were determined using a voxelwise Bayesian method with uniform prior distributions and mode as central tendency measure [52] Parameter limits were D: [0,5] μm2/ms, f: [0,1], D*: [0,1000] μm2/ms, S0: [0, 2xSmax], where Smax is the maximum measured signal
D	Diffusion coefficient	The tissue water diffusion coefficient
D*	Pseudodiffusion coefficient	Perfusion-related pseudodiffusion coefficient of incoherently flowing blood in the tissue
f	Perfusion fraction	Signal fraction from incoherently flowing tissue water (blood)
		Apparent diffusion S(b) = S0e−b ∙ ADC S0: signal without diffusion weighting The model was fitted using least squares with two b values (0 and 800 s/mm2.)
ADC	Apparent diffusion coefficient	The apparent diffusion coefficient affected by both diffusion and perfusion
Relaxation time mapping
		T1 relaxation $S\left(\mathit{TR}\right)=A+C\left(1-e^{-\frac{\mathit{TR}}{T1}}\right)$ S(TR) = signal intensity for repetition time TR A = signal bias C = signal intensity after complete T1 relaxation with no bias The parameters were estimated by a least squares fit
T1	T1 time	Longitudinal relaxation time of tissue
		T2* relaxation $S\left(\mathit{TE}\right)=A+C{e}^{-\frac{\mathit{TE}}{T{2}^{\ast }}}$ S(TE) is the signal intensity for echo time TE A = signal bias C = signal intensity without T2* relaxation and no bias T2* was determined by least squares fit. The goodness-of-fit parameter R2 was used to exclude voxels with R2< 0.4
T2*	T2* time	Transversal relaxation time of tissue including effects from magnetic field inhomogeneity
DCE-MRI
		Semiquantitative characteristics S(t), a continuous representation of signal intensity as a function of time, was determined by fitting a smoothing spline (smoothing parameter = 0.01) S0, the baseline signal intensity, was defined as the mean of the precontrast dynamics σvoxel, the voxel noise, was defined as the standard deviation of the residuals of S(t) for each voxel S(t) > S0 + 5 ∙ σvoxel defined significant contrast enhancement σimage, the image noise, was defined as the mean of σvoxel S0 > 5 ∙ σimage defined the threshold for inclusion of voxels in the analysis Smax was defined as the maximum value of S(t) for each voxel
AT	Arrival time	Time after injection required for signal intensity to reach significant enhancement
TOP	Time of peak intensity	Time after injection required to reach maximum signal intensity
TTP	Time to peak	Time between AT and TOP
SEmax	Relative, maximum signal enhancement	Maximum signal intensity relative to baseline signal intensity: (Smax– S0)/S0
SE60	Relative signal enhancement at 60 s	Signal intensity at 60 s after injection relative to signal baseline intensity: [S(60 s) – S0]/S0
SER	Signal enhancement ratio	Ratio of early (55 s) and late (300 s) relative signal enhancements
CER	Contrast enhancement ratio	Ratio of maximum signal intensity and baseline signal intensity: Smax/S0 Missing value if no significant enhancement was obtained
AUCn	Normalized area under the curve	Area under S(t) between 0 and 5 minutes, normalized to S0
WI	Wash in	Maximum time derivative of S(t) between AT and TOP
WO	Wash out	Maximum negative time derivative of S(t) between TOP and the last dynamic. Missing value if <5 dynamics left after TOP
BE	Brevity of enhancement	Time between the time points of WI and WO
IS	Initial slope	Average rate of signal enhancement between TOP and contrast injection: (Smax − S0)/TOP
NS	Negative slope	Average rate of signal decrease between TOP and the last dynamic. Missing value if <5 dynamics left after TOP