Fig 2. Time-series modeling method applied to extract lesion dynamics: a mathematical model is fit to the time series of each lesion pixel. The model emulates 2 opposing processes (I₁-I₂) driving the T2 signal intensity toward hyperintensity and isointensity, respectively. A, Example of a new lesion, marked by a 3D bounding box, and the time series of this lesion showing its appearance in week 6, reaching peak around week 9, and end of activity around week 21. B, Example profiles extracted at 3 points within the lesion, and the resulting model fit. C, Mathematical model and the extracted characteristics: peak hyperintensity (relative to baseline) residual hyperintensity (relative to peak), and the duration of activity (split into an acute, subacute and chronic phase). These characteristics are then shown for each lesion pixel in color maps (D), revealing spatial patterns of lesion dynamics.