MR measurement of spinal CSF flow with the RACE technique

The purpose of our study was the application and validation of a phase-sensitive pulse sequence that allowed real time CSF flow measurement without need for electrocardiographic (ECG) synchronization. After excitation of a slice perpendicular to the axis of the spine, projective data were obtained with a gradient echo sequence [contrast enhanced Fourier acquired steady-state technique (CE-FAST)] without spin warp gradient [real time acquisition and evaluation of motion technique (RACE)], allowing one-dimensional spatial resolution across the region of interest with a total sampling time of 20-30 ms. The sequence was calibrated with a spinal CSF phantom with oscillatory fluid motion. The calculated mean pulsation amplitudes of 20 healthy volunteers in the cervical region were 16 mm (range 9-36 mm), in the thoracic region 11 mm (5-21 mm), and in the lumbar region 3 mm (1-6 mm). The technique was capable of demonstrating physiologic alterations of CSF flow during respiratory maneuvers and may provide a tool to evaluate the altered CSF dynamics resulting from spinal block, inflammatory processes, or hemorrhage.