Direct Visualization and Quantitation of CSF flow in Shunts

Introduction Diversion of excessive cerebral spinal fluid (CSF) from hydrocephalic brains by shunting is, in many cases, a life saving procedure. The down side of shunting is high failure rate (40% in the first year, and about 10% annually thereafter). Consequently, about 43% of the estimated 40,000 shunting procedures performed annually in the US alone are for shunt replacement. A study of implanted ventricular shunts in the US found the annual cost of treatment in the year 2000 exceeded one billion dollars [1]. The decision for shunt replacement is often challenging as there is no reliable noninvasive diagnostic test for shunt function. A reliable noninvasive measurement of volumetric flow through shunts may therefore improve the decision for shunt replacement and perhaps reduce unnecessary shunting procedures.