Fig. 5.

a Illustration of axial parameter maps of $K_1$($\text{ml/g/min}$), $k_2\left(1/\text{min}\right)$, $k_3\left(\text{1/min}\right)$, and $K_i$ ($\text{ml/g/min}$) from Participant 5 produced using the 24-min short imaging window. b Map of $K_i$ ($\text{ml/g/min}$) obtained using Patlak analysis of validation window data (0–36 min). c and d, respectively, depict plots of regional mean $K_i$ values and voxel-wise $K_i$ values determined using the 2TCM for short imaging window data and Patlak analysis for validation imaging window data in the six participants (P1–P6). c The brain $K_i$ maps were segmented into 14 primary brain regions including the caudate, cerebellum, anterior cingulate, posterior cingulate, frontal, hippocampus, insula, putamen, occipital, parietal, lingual, midtemporal, medial temporal, thalamus and white matter, available in the MNI AAL atlas. $K_i$ values were averaged over these ROIs. d Voxel-wise scatter plot. The Pearson correlation coefficient ($r$) was calculated between the $K_i$ estimated from the short imaging and validation windows