MR Measurement of Pulse Wave Velocity in the Spinal Canal

Non-invasive measurement of pulse wave velocity (PWV) in the cerebrospinal fluid (CSF) system is of interest as a potential indicator of subarachnoid space pressure and compliance, both of which play a role in the development of craniospinal diseases. However, measurement of PWV has eluded researchers primarily due to either a lack of access to CSF velocity measurements or to poor temporal resolution. Here, we present PWV measurements using a novel MR technique that acquires unsteady velocity measurements during the cardiac cycle with a time interval <10 ms. Axial CSF velocity measurements were obtained in the sagittal plane of the cervical spinal region on three patients without cranio-spinal disorders. PWV was estimated by using the time shift identified by the maximum temporal velocity gradient during the cardiac cycle. Based on the maximum velocity gradient, the mean PWV in the three cases was calculated to be 4.6 m/s (stdev 1.7 m/s, p<0.005) during systolic acceleration. The measurements of PWV agree with previously published values.