Radionuclide cisternography: imaging and study of the cerebrospinal fluid circulation

[摘要] English: English: Radionuclide cisternography performed in 200 selected patientswith neurological disease has proved to be a simple and relatively safe procedure, v,rithminimal disturbing side effects,which can provide useful information about cerebrospinal fluid(eSF) flow and dynamics.Following the subarachnoid or ventricular injection of an appropiate radiopharmaceutical, the tracer flows with the eSFand demonstrates the pathways of circulation under normal andabnormal conditions with virtually no disruption of the existing eSF physiology.The eventual distribution of the tracer is complex. The rangeof normal varies from rapid ascent with early absorption of theradiopharmaceutical to slower ascent and absorption, frequentlywith laterilization of flow to one or other side intracraniallyand occasionally with transient ventricular reflux.In pathological states the cisternographic picture varies ac=cation (or lack of it) of the ventricles with the subarachnoidcording to the underlying disease. It may lack the ability toestablish the precise anatomical features available from airencephalography. However ventricular dilatation, the communispace, and the delay or lack of absorption are only satisfactorily demonstrated by radionuclide cisternography. Repeatedexaminations may be readily performed to show progression ofthe disease or the results of surgical treatment.The abnormal flow pattern in patients with normal pressurehydrocephalus proved to be the most important criterion intheir selection for extracranial neurosurgical eSF shunting.When properly selected, these patients often respond to surgical treatment. The routine use of radionuclide cisternography in the examination of patients with suspected preseniledementia and compensated hydrocephalus results in a low yieldof operable patients. When operation is contraindicatedconservative management of the patient is then institutedand unnecessary surgical intervention avoided.Radionuclide cisternography gained wide acceptance in theevaluation of shunt patency. The test is fast and safe inthe presence of extracranial diversionary eSF shunts. Therapid flow into the cerebral ventricles and the fast disappearance of the radioactive tracer, as well as the relativesize of the ventricular system, are valuable indexes for thedetermination of patency and efficaccy of the shunt. Anotherimportant use of radionuclide cisternography is the investigation of eSF leaks and eSF spinal flow obstruction. It maydemonstrate the existence and site of eSF leakage or blockand offer valuable assistance to the neurosurgeon.Radionuclide cisternographic images are usually interpretedsubjectively on the basis of abnormal regional and temporalconcentrations of radiopharmaceuticals in the eSF space. Theevaluation of images can be improved by the use of quantitative computerized digital scanning, increasing the sensitivity and value of the measurements.The further extension of these studies involving abnormalities of cerebrospinal fluid dynamics would seem worthwhile,and the value of the methods described in this thesis and theirlimitations, remain a potential and challenging field forfurther exploration.

[发布机构] University of the Free State