CINE-MR IMAGING OF AQUEDUCTAL CSF FLOW IN NORMAL-PRESSURE HYDROCEPHALUS SYNDROME BEFORE AND AFTER CSF SHUNT

Reproducibility of the aqueductal CSF signal intensity on a gradient e cho cine-MR sequence exploiting through plane inflow enhancement was t ested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated w ith the sequence before and after CSF shunting. Two patients exhibitin g central flow void within a hyperintense aqueductal CSF improved afte r surgery and the flow void disappeared after shunting. One patient wi th increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was co nsiderably decreased after shunting. Three patients with aqueductal CS F values similar to those in the controls did not improve, notwithstan ding their maximum aqueductal CSF signals decreasing slightly after sh unting. No appreciable aqueductal CSF flow related enhancement consist ent with non-communicating hydrocephalus was found in the last NPH pat ient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal change s which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.