English: Fig. 4: Five-dimensional imaging of mouse brain perfusion in vivo. (a) Layout of the experimental set-up. (b) Maximal-intensity projections along the axial direction following single-wavelength illumination before and after injection of two concentrations of contrast agent, indocyanine green. The lower concentration does not provide strong signal over the background signal from blood. Different structures in the mouse brain are indicated: sv, supraorbital veins; icv, inferior cerebral vein; sss, superior sagittal sinus; cs, confluence of sinuses; ts, transverse sinus. (c) Time series of maximal-intensity projections following multi-wavelength illumination after injection of 10 nmol indocyanine green. Inflow of the contrast agent can be followed in real time.