This study introduces a novel noninvasive imaging technique, termed shunt flow enhancement of signal intensity (shunt-FENSI), designed to accurately assess very slow cerebrospinal fluid (CSF) flow within shunt tubes in pediatric patients with hydrocephalus. The technique aims to identify obstructions that might impede CSF drainage. It involves a simulation to establish the relationship between signal change and flow rate, incorporating a phase sweep method to address magnetic field inhomogeneity effects. Tested in flow phantoms, healthy adults, ICU patients with external ventricular drains (EVD), and shunt patients, the method shows promise in reliably quantifying CSF flow rates. Results indicate the technique’s potential for diagnosing and monitoring hydrocephalus noninvasively, with limitations including sensitivity to motion and strict imaging requirements. This development is significant as it offers a new tool for the noninvasive evaluation of shunt functionality, potentially improving patient care in hydrocephalus management.