Radionuclide cisternography: imaging and study of the cerebrospinal fluid circulation
Abstract
English: English: Radionuclide cisternography performed in 200 selected patients
with 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 eSF
and demonstrates the pathways of circulation under normal and
abnormal conditions with virtually no disruption of the existing eSF physiology.
The eventual distribution of the tracer is complex. The range
of normal varies from rapid ascent with early absorption of the
radiopharmaceutical to slower ascent and absorption, frequently
with laterilization of flow to one or other side intracranially
and occasionally with transient ventricular reflux.
In pathological states the cisternographic picture varies ac=
cation (or lack of it) of the ventricles with the subarachnoid
cording to the underlying disease. It may lack the ability to
establish the precise anatomical features available from air
encephalography. However ventricular dilatation, the communispace, and the delay or lack of absorption are only satisfactorily demonstrated by radionuclide cisternography. Repeated
examinations may be readily performed to show progression of
the disease or the results of surgical treatment.
The abnormal flow pattern in patients with normal pressure
hydrocephalus proved to be the most important criterion in
their 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 presenile
dementia and compensated hydrocephalus results in a low yield
of operable patients. When operation is contraindicated
conservative management of the patient is then instituted
and unnecessary surgical intervention avoided.
Radionuclide cisternography gained wide acceptance in the
evaluation of shunt patency. The test is fast and safe in
the presence of extracranial diversionary eSF shunts. The
rapid flow into the cerebral ventricles and the fast disappearance of the radioactive tracer, as well as the relative
size of the ventricular system, are valuable indexes for the
determination of patency and efficaccy of the shunt. Another
important use of radionuclide cisternography is the investigation of eSF leaks and eSF spinal flow obstruction. It may
demonstrate the existence and site of eSF leakage or block
and offer valuable assistance to the neurosurgeon.
Radionuclide cisternographic images are usually interpreted
subjectively on the basis of abnormal regional and temporal
concentrations of radiopharmaceuticals in the eSF space. The
evaluation 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 their
limitations, remain a potential and challenging field for
further exploration. Afrikaans: Radionuklied-sisternografie is by 200 geselekteerde pasiënte
met neurologiese aandoenings uitgevoer. Dit is gevind om 'n
eenvoudige en veilige ondersoekprosedure te wees - 'n tegniek
met minimale komplikasies, wat nuttige inligting betreffende
serebrospinale vloeistof (S.S.V.)-vloei en ~dinamika verskaf.
Na die subaragnoiedale of ventrikulêre inspuiting van 'n geskikte radiofarmaseutiese materiaal, volg die merker die
S.S.V.-vloeibaan. Sonder versteuring van S.S.V.-fisiologie
kan die vloeipatroon by normale of abnormale toestande dan bestudeer word. Die uiteindelike verspreiding van die radioaktiewe
merker word bepaal deur komplekse faktore sekondêr
tot die patologiese en patofisiologiese aard van die besondere siektetoestand.
Die normale patroon van isotoopvloei na spinale inspuiting
wissel van persoon tot persoon. Daar mag vinnige styging
van merker met verspreiding oor die serebrale hemisfere, en
snelle absorpsie wees, of relatief vertraagde vloei en
absorpsie - selfs met 'n mate van intrakraniale isotoop-lateralisering. Soms word kortstondige ventrikulêre refluksvulling
selfs opgemerk.
Die skerpomlynde anatomiese afbeelding van S.S.V.-ruimtes by
lugenkefalografie verkry, ontbreek kwalitatief by radionukliedsisternografie.
Andersynds word ventrikulêre uitsetting met
refluks, S.S.V.-verbindings tussen die ventrikels en die subaragnoiedale ruimte as geheel, asook vertraagde of gebrekkige S.S.V.-absorpsie slegs met sisternografie bevredigend gedemonstreer. Herhaalde ondersoeke kan voorts uitgevoer word
om die verloop van 'n siektetoestand of die gevolg van chirurgiese behandeling te beoordeel.
Die abnormale S.S.V.-vloeipatroon kenmerkend van normale drukhidrokefalus,
was een van die nuttigste kliniese toepassings
van sisternografie - veral by die sorgvuldige selektering van
pasiënte geskik vir ekstrakraniale neuro-chirurgiese aftakkingsprosedures. Hierdie terapeutiese ingreep lei dan dikwels tot
omkering van die siekteproses en verbetering van simptome. Alhoewel die roetine gebruik van radionuklied-sisternografie by
die ondersoek van vermoedelike preseniele demensie en gekompenseerde hidrokefalus gelei het tot 'n lae opbrengs van pasiënte geskik vir vermelde operasie, is 'n negatiewe bevinding tog nuttige bevestiging dat konserwatiewe terapie ingestel
en chirurgiese ingrepe vermy moet word.
Radionuklied-sisternografie is ook van groot waarde by die
doeltreffendheidsbeoordeling van aftakkingsprosedures. So
'n ondersoek kan vinnig en veilig uitgevoer word deur isotoop in die ventrikel te plaas. Die opruimingsnelheid vanuit
die serebrale ventrikels, asook die relatiewe grootte van
die ventrikulêre sisteem is waardevolle aanduidings van die
doeltreffendheid van die ekstrakraniale aftakking.
Ander waardevolle gebruike van radionuklied-sisternografie
sluit in die ondersoek van S.S.V.-lekkasie en obstruksie van spinale S.S.V.-vloei. Dit het unieke waarde by die presiese
anatomiese lokalisering van areas van S.S.V.-lekkasie.
Die nut van sisternografie, op die basis van subjektiewe beoordeling van abnormale vloeipatrone of regionale konsentrasie van radio-farmaseutiese stowwe in die S.S.V.-ruimte, kan
aangevul word deur gebruik te maak van kwantitatiewe gerekenariseerde digitale flikkergrafie.
Die verdere uitbreiding van hierdie studies waardeur abnormaliteite van S.S.V.-vloei atrournaties beoordeel word, bied
vele toekomsmoontlikhede op die gebied van kliniese gebruik
en navorsing.