Deformation of the human brain induced by mild angular acceleration

Deformation of the human brain was measured in tagged magnetic resonance images (MRI) obtained dynamically during angular acceleration of the skull. This study was undertaken to provide much needed experimental data for the quantitative study of traumatic brain injury (TBI). A custom device was made to impart mild angular acceleration to the skull of a human volunteer inside an MR scanner. Images with a superimposed grid of "tag" lines were obtained using spatial modulation of magnetization (SPAMM) in a fast gradient-echo imaging sequence. Images of the moving brain were obtained dynamically by synchronizing the imaging process with the motion of the head. The deformation of the brain was characterized quantitatively with Lagrangian strain. Strain fields showed reduced strain along the central fissure and to a lesser degree, the central sulcus, suggesting that divisions between regions of the brain may serve to mechanically isolate these regions. Results emphasize the critical role of the brain's suspension, including the dura mater, falx cerebri, and tentorium membranes, in modulating its deformation.