BACKGROUND: Arteriovenous malformations (AVM) markedly alter the distribution
of the regional cerebral blood flow, as they consist of abnormal arteries and
veins with no resistance vessels between them. The aim of this study was to the
evaluate diagnostic utility of cerebral perfusion scintigraphy (dynamic phase
and SPECT) in patients with AVM.
MATERIAL AND METHODS: Nineteen patients were examined. All the patients
had been previously diagnosed with AVM and qualified for intravascular embolization.
Brain scintigraphy was performed with 99mTc-ECD and included dynamic phase and
SPECT imaging. The regional blood flow was evaluated visually and semi quantitatively,
based on comparison between the activity in the two symmetrical regions of interest.
Differences higher than 10% were considered significant. Cerebral angiography
combined with intravascular embolization was carried out after a scitigraphic
examination.
RESULTS: Based on angiograms, the diameter of the AVM nidus was estimated
and varied from 1.0 cm to 9.0 cm. In 13 cases, AVM were visible in the dynamic
scintigraphy as areas of increased tracer activity. In each case, SPECT images
showed the AVM nidus as a region of decreased tracer accumulation. Hypoperfusion
in the brain tissue adjacent to the nidus was seen in 15 subjects. In one patient
cerebellar diaschisis was present. The average ratio of activity in the region
of AVM to activity in the normally perfused tissue calculated by semiquantitative
analysis was 77.5 ± 10.9%.
CONCLUSION: Cerebral perfusion scintigraphy (SPECT images and dynamic scintigraphy)
allows one to identify perfusion disturbances caused by the presence of intracranial
AVM