Phase-contrast MRI at the spinal canal: Range of spinal cord motion and CSF flow, and impact of clinical and anatomical parameters

Background: Recent studies detected increased spinal cord, and CSF dynamics at the cervical spine in different diseases: spontaneous intracranial hypotension, normal pressure hydrocephalus, degenerative cervical myelopathy. Objective To explore the physiological range, and impact of clinical and anatomical parameters. Method Prospective study, 70 healthy volunteers. MRI cervical spine: (1) 3D T2-weighted MRI, (2) phase-contrast MRI; dynamic parameters per heartbeat: peak-to-peak amplitude (mm/s, velocity range), total displacement (mm). Spinal canal narrowing, age, height, BMI, sex, blood pressure were assessed. Results Dynamics increased across the spine (e.g., peak-to-peak amplitude C2/C3-C5/6 - spinal cord: 6.0 ± 2.0 mm/s; 7.1 ± 2.9; mm/s, CSF 45 ± 11 mm/s, 73 ± 25 mm/s; p < 0.001 each). Physiological spinal canal narrowing caused higher dynamics (e.g., peak-to-peak amplitude C5/C6 spinal cord: B = + 1.1 mm/s, p = 0.001; CSF: B = + 16.4 mm/s, p < 0.001). +10 years, and + 10 mmHg diastolic blood pressure were associated with lower dynamics (e.g., peak-to-peak amplitude C2/C3 spinal cord: B=-0.4mm/s, p = 0.010, B=-0.7 mm/s, p = 0.030; CSF: B=-3.1 mm/s, p < 0.001, B=-2.6 mm/s, p = 0.048, respectively). Male sex indicated higher dynamics (e.g., total displacement C2/C3 spinal cord B = + 0.16 mm, p = 0.004; CSF B = + 2.2 mm, p = 0.007). Discussion We propose to stratify data for age and sex, and to correct for diastolic blood pressure and segmental narrowing in further clinical trials.