Radionuclide cisternography and computed tomography in 30 healthy volunteers.

Radiological assessments of patients with symptoms of impaired cerebrospinal fluid (CSF) circulation are usually based on observations of anatomical and functional alterations using computed tomography (CT) and radionuclide cisternography (RC). In order to define criteria of normality for these two techniques, 30 healthy volunteers have been studied. In the studies of CSF flow the radiopharmaceutical 99mTc-DTPA was used and single photon emission computed tomography (SPECT) was performed as a complement to planar scintigraphy. In 16 of the 30 volunteers the pattern of CSF flow was normal according to conventional criteria. In these subjects the radioactivity was symmetrically located over the parietal cortex 24 h after the injection and no intraventricular activity could be recorded. In 11 (41%) of the subjects, radioactivity could be observed in the lateral ventricles 6 h after injection. One of these subjects had a reflux of radioactivity into the lateral ventricles. The intraventricular radioactivity persisted for at least 24 h. This subject also had signs of obstruction of CSF flow over the convexities. Asymmetric distribution of radioactivity within the CSF spaces was observed in the images obtained after 6 but not 24 h in two cases. One of those also demonstrated transient intraventricular radioactivity. The results of the computed tomography were interpreted to be normal in 19 (63%) of the 30 volunteers. One subject had an asymmetric ventricular system. The CT scans of six subjects (20%) differed considerably from the others as they displayed wide cortical or vermian sulci at the borderline of normal variations. The case with the pathological RC belonged to the group of subjects who had wide sulci.(ABSTRACT TRUNCATED AT 250 WORDS)