Transport of the contrast agent along the optic nerve. (A) Timeline of intracisternal injection of Gd-DTPA contrast agent. (B) MRI imaging of the brain after injection. (C) High-magnification image of the optic nerve in MRI. (D and E) Coronal and sagittal MRI images at different time points. A high reflectance signal of the contrast agent in the periorbital tissue was indicated by white arrowheads. (F) Line graph of contrast agent signal intensity in the eye area at different time points on MRI images.