Cine (phase-contrast) MRI — CSF flow study

What it is

A cine (phase-contrast) MRI, or CSF flow study, is a specialized MRI scan that visualizes the movement of cerebrospinal fluid at the craniocervical junction over the cardiac cycle. It helps assess the degree of CSF flow obstruction in Chiari malformation.

Understanding Cine (phase-contrast) MRI — CSF flow study

Unlike a standard MRI that shows anatomy at a single moment, a cine MRI captures CSF flow in motion, showing how fluid moves back and forth across the foramen magnum with each heartbeat. In Chiari malformation, it can reveal reduced, restricted, or abnormal CSF flow behind the descending tonsils — providing functional information beyond the static anatomy. This can help support the diagnosis (especially in borderline cases), assess how significantly the flow is obstructed, and, in some studies, help predict who is likely to benefit from surgery (presurgical CSF flow at the craniocervical junction has been associated with good outcomes after decompression). Cine MRI is a valuable complement to standard imaging. Understanding cine MRI clarifies how CSF flow — not just anatomy — is assessed in Chiari.

Why it matters

Understanding cine MRI helps families see how a flow study adds functional information about the CSF obstruction in Chiari — supporting diagnosis in borderline cases and, in some situations, helping predict surgical benefit.