Radioisotope cisternographic evaluation of hydrocephalus: Comparison with CT, MRI, and clinical findings

ABSTRACT

To evaluate the clinical usefulness of radionuclide(RI) cisternography in patients with hydrocephalus, we retrospectively analyzed RI cisternographic findings of 47 patients by using our classification which was modified from Baum's. and correlated them with CT(n=37) or MRI(n=10) findings and clinical outcome in selected patients with hydrocephalus(n=37). Modified RI cisternographic patterns of 37 patients were type I in three cases(8%), type II in seven(18%), type III-A in six(16%), no case of type III-B, type IV-A in 12(32%), and type IV-B in nine(24%). RI cisternography enabled to differentiate communicating hydrocephalus(27 cases, 73%) from noncommunicating hydrocephalus (10 cases, 27%). There was marked clinical improvement in 17 patients(46%), slight improvement in 11 patients(30%), and no improvement in nine patients(24%). The clinical outcome of patients with RI cisternographic type IV-B was worse than that of other types. CT and MRI could neither predict the clinical outcome nor differentiate type IV-B from Type IV-A(p>.05). Ventricular size index (VSI( was significantly higher in patients with type IV than that with other types(p<.001). RI cisternographic patterns of communicating hydrocephalus were relatively correlated with clinical outcome (r=-0.53, P=.001), VIS(r=0.59, p=.001), and dilatation of fourth ventricle(r=0.41, p<.05). We suggest that our modified classification of RI cisternographic patterns can provide more strict physiological assessment of the CSF dynamics and RI cisternography may be still useful to differentiate communicating hydrocephalus from noncommunicating hydrocephalus and to predict the clinical outcome in conjunction with CT/MR findings and clinical presentation.