Is a Velocity Encoding of 5 Cm/sec Sufficient to Quantify Brain Motion?

Guillaume Calmon^1,2, Marc Labrousse, ^1,3, Gabriela Hossu⁴, Jacques Felblinger^1,4, Marc Braun^1,5

Brain motion during cardiac cycle, linked to the one of cerebro-spinal fluid (CSF), presents interesting challenges and can have an interest to analyze brain elastography. In this study, we measured brain speed and motion in volunteers at the level of thalamus and brain stem. A velocity encoding of 5 cm/sec was sufficient to obtain brain values consistent with literature. Absolute brain tissue speeds were measured between 0.0002 and 0.17 cm/sec in thalami ROIs and between 0.0014 and 0.48 cm/sec in brain stem ROIs. There was a decreased of motion with cardiac frequency and with age in certain territories.