Noninvasive Measurement of Cerebrospinal Fluid Flow in Shunted Hydrocephalus: Protocol for Scanner Calibration and...

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Neurosurgery

Background:

• Ventricular shunts are critical for managing hydrocephalus, but shunt malfunction can lead to severe neurological injury.
• Diagnosing shunt malfunction is complex, lacking simple, noninvasive methods for quantitative cerebrospinal fluid (CSF) flow measurement.
• Phase-contrast magnetic resonance imaging (PC-MRI) offers a new noninvasive approach to quantify shunt flow, but requires standardization across diverse MRI hardware.

Purpose of the Study:

• To develop and standardize a protocol for PC-MRI measurement of CSF flow through ventricular shunts.
• To ensure the protocol is applicable across various magnetic resonance (MR) scanner models and manufacturers.
• To facilitate widespread clinical implementation of accurate, noninvasive shunt flow monitoring.

Main Methods:

• A phantom model with a human shunt catheter was constructed to simulate physiological CSF flow rates.
• Calibration curves were generated by comparing known flow rates to PC-MRI measurements.
• The protocol was validated on 8 MR scanners to assess accuracy using linear regression before multisite data collection.

Main Results:

• A shunt flow phantom was successfully constructed and utilized for single-site calibration.
• Data collection is ongoing, with multi-institutional clinical data collection scheduled from July 2026 to January 2027.
• Results and statistical analyses are anticipated by April 2027.

Conclusions:

• The study protocol provides a robust methodology for testing and implementing PC-MRI on any MR scanner.
• The phantom model accurately represents real flow conditions, ensuring repeatable and artifact-minimized data collection.
• The protocol includes analytic methods for interscanner calibration and a framework for multisite data collection, promoting standardized shunt monitoring.