Abstract
Purpose
To quantify periodic displacement in the cranium using complementary spatial modulation of magnetization (CSPAMM) with harmonic phase (HARP) postprocessing.
Materials and Methods
CSPAMM tagging sequence with separate tagโline preparation in two orthogonal directions was applied on 10 healthy volunteers in combination with HARP for tissue displacement mapping.
Results
Important features of brain dynamics, such as caudal displacement amplitude and the timeโtoโpeak of the pulse wave were derived for six regions in the brain. Peak displacement values amounted to 0.18 ยฑ 0.02 mm, 0.10 ยฑ 0.01 mm, 0.09 ยฑ 0.02 mm, and 0.04 ยฑ 0.01 mm for regions in the pons, cerebellum, corpus callosum (splenium), and frontal lobe, respectively. Displacement values of the pons differed significantly from all other regions measured. With the additional information of the timeโtoโpeak measure all six regions except the corpus callosum (splenium) and cerebellum can be distinguished. The values found suggest that the pulse wave travels from the brain stem first occipitally and then to the frontal lobe, where peak values appear later and are significantly attenuated.
Conclusion
Direct quantification of periodic caudal brain tissue displacement is feasible with the proposed method, and several brain regions can be distinguished through peak displacement and timeโtoโpeak values. J. Magn. Reson. Imaging 2007. ยฉ 2007 WileyโLiss, Inc.