Comparative Evaluation of Morphological Findings and FlowSensitive Magnetic Resonance Parameters in Patients with Chiari 1 Malformation Against Healthy Individuals

Introduction: A better understanding of the cerebrospinal fluid (CSF) flow dynamics of Chiari 1 malformation (CM-1) may help to reach more specific parameters for indicating therapy and response to therapy. This study developed a parameter to better characterize CSF flow alterations in the cerebral aqueduct in patients presenting with CM-1. Methods: We retrospectively scanned archives for CM-1 patients who underwent CSF flow analysis between January 2016 and December 2022. Eighty-eight CM-1 patients and 83 control cases were included in the study. The cerebellar tonsillar descensus was measured in all patients. In 11 cases with the syrinx cavity, the largest transverse diameter of the cavity was measured. Phase-contrast magnetic resonance imaging was performed using a 1.5 T scanner. Peak velocity (P-Vel) (cm/s), average velocity (A-Vel) (cm/s), forward flow volume (mu L), reverse flow volume (mu L), peak flow (P-Fl) (mL/s), and time to peak velocity (TP-Vel) (s) and cerebral aqueduct's stroke volume (mu L) were calculated. Sixteen CM-1 patients underwent decompression surgery, and we examined postoperative CSF flow analyses. Results: A-Vel and P-F1 were statistically significantly higher in CM-1 cases than in controls (p=0.006, p=0.037). There was a significant negative correlation between the diameter of the syrinx cavity and P-Vel and P-Fl, and a positive correlation between TP-Vel. We found no significant difference between the postoperative and preoperative CSF flow parameters of the CM-1 patients. Conclusion: P-Fl differs between the patient and control groups and correlates with the syrinx diameter; therefore, it could be a useful parameter in CSF flow analysis in CM-1 cases. However, higher case numbers can achieve more effective results.