MR imaging and quantification of the movement of the lamina terminalis depending on the CSF dynamics.

BACKGROUND AND PURPOSE Brain pulsation is a well-known observation in neurosurgery, but methods for its visualization on MR imaging, like phase imaging, do not provide a detailed structural view. We prospectively investigated electrocardiographic (ECG)-gated cine true fast imaging with steady-state precession (FISP) sequence on volunteers to test a sequence for demonstrating brain pulsation and movements of intracranial structures related to CSF dynamics. MATERIALS AND METHODS Eleven healthy volunteers were investigated with prospectively ECG-gated cine true-FISP in the midsagittal plane. A total of 50 phases were recorded per cardiac cycle and per volunteer. The lamina terminalis was chosen to study the pulsatility of the brain, and the optic recess diameter was chosen for means of objective quantification of the degree of pulsatility. RESULTS Pulsatile motion of the lamina terminalis was apparent in all volunteers on the cine mode. The mean diameter of the optic recess was 2.5 mm. The greatest change in diameter in 1 volunteer was 1.5 mm. The mean change in diameter was 40% during 1 cardiac cycle. CONCLUSIONS Cine true-FISP sequence is a well-suited method for investigations of passive movements of the ventricular system. It shows pulsations of the brain as well as passive changes caused by CSF dynamics with high temporal and spatial resolution.