CSF dynamics are thought to be indicative of Chiari I malformation (CM) severity. The accurate detection and assessment of abnormalities in CSF dynamics could help in clinical decision-making. However, studies utilizing 2D PC MRI as a tool to assess CSF dynamics have brought mixed results. Some have found CSF velocities to be greater in CM patients pre-surgery than healthy volunteers [1,2] while others found smaller velocities pre-surgery [3,4]. The inherent limitation of 2D PC MRI to one measurement plane and a single velocity direction (e.g. z-direction) may account for these seemingly conflicting results [5,6].
Our research team is leading the usage of a novel 4D PC MRI protocol for quantification of complex CSF flow dynamics in CM [5,7-9]. This protocol has an advantage over 2D PC MRI because it encodes velocity in 3D (x, y, and z) over a volume of interest. The technique has shown promising results to differentiate CM patients from healthy controls and CM patients with and without a syrinx based on peak CSF velocity analysis . However, one drawback of the 4D PC MRI technique is that it has not been rigorously tested for a known flow condition representative of CSF in CM (e.g. in vitro model of CM).
We hypothesize that 4D PC MRI will compare favorably with the bench-top and computational fluid dynamics simulations and be useful to detail the complex 3D flow field present in each of the three models. We further hypothesize that the 4D PC MRI measurements will be consistent between MRI scanners in terms of overall CSF flow features but will be altered by a scanner dependent scaling factor.