Atrophy rate | r | p value |
---|
RIVIM-PARs |
 RADC | −0.418 | 0.011a |
 RD | 0.066 | 0.702 |
 RD* | 0.038 | 0.825 |
 Rf | −0.449 | 0.006a |
RDCE-PARs |
 RMRE | −0.372 | 0.025a |
 RTTP | 0.208 | 0.223 |
 RWash in Rate | −0.136 | 0.428 |
- IVIM Intravoxel incoherent motion, DCE Dynamic contrast-enhanced, r Pearson correlation coefficient, RIVIM-PARsand RDCE-PARs are the change rates of IVIM and DCE MR parameters from pre-RT to post-RT, respectively, R
ADC
, R
D
, RD*, R
f
, R
MRE
, R
TTP
and R
Wash in Rate
are the change rates of apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), maximum relative enhancement (MRE), time to peak (TTP) and Wash in Rate from pre-RT (2Â weeks before radiotherapy) to post-RT (4Â weeks after RT), respectively
- adenotes a significant correlation between the parotid atrophy rate and the change rate of each IVIM or DCE MR parameter