Principles, Techniques, and Clinical Applications of Phase-Contrast Magnetic Resonance Cerebrospinal Fluid Imaging

The CSF compartment is dynamic and more complex than previously believed, and there is increasing recognition that abnormalities of CSF flow can be causes or markers of disease. Phase-contrast MRI, commonly used in MR angiography, has also proved to be useful as a reliable and both qualitative and quantitative method of evaluating pulsatile (“to and fro”) CSF flow. Phase-contrast MRI has often been used for the evaluation of normal pressure hydrocephalus, Chiari I malformations, and syringomyelia, and response to endoscopic third ventriculostomy. Phase-contrast MRI can be useful in normal pressure hydrocephalus, both in the diagnosis and in predicting those who would benefit from shunt surgery by examining flow at the cerebral aqueduct, although this latter indication is controversial. The use of phase-contrast MRI to evaluate CSF flow dynamics at the foramen magnum is an area of increasing research interest and may be useful in predicting outcomes and in monitoring the response to posterior fossa decompression surgery in patients with Chiari I malformation. Phase-contrast MRI can also be used to distinguish syringomyelia from its common mimic, myelomalacia. The response to endoscopic third ventriculostomy, used as an alternative to shunt surgery in both communicating and noncommunicating hydrocephalus, can be monitored with phase-contrast MRI.

Learning Objective: Describe the technique of phase-contrast MRI of CSF flow, describe the technique's challenges and limitations, and identify areas in which this technique may be clinically useful for diagnosis, prognosis, and disease monitoring after treatment.