Published data describing scintigraphic evaluation of perfusion changes in patients with cerebral arteriovenous malformations (AVMs) after embolization are very scarce. The aim of our study was to evaluate these changes by using 99mTc-ethyl cysteinate dimer single photon emission computed tomography.Materials and methods
The examinations were performed in 20 patients before and after the treatment. Voxel-based analysis was used for semiquantitative assessment of single photon emission computed tomography. Hypoperfusion in basal single photon emission computed tomography was diagnosed when asymmetry index was higher than 10% in a cluster volume (CV) greater than 10.0 ml. The change of perfusion between basal and control studies was considered significant when relative difference (RD) was higher than 10% in a CV greater than 10 ml.Results
Obliteration of AVMs was total or nearly total in 12 patients and partial in 8 patients, No serious complications were observed after the procedure. Before embolization hypoperfusion in the region of an AVM was seen in 17 cases, perfusion defects in areas distant from an AVM were found in 12 patients. After embolization, perfusion around an AVM deteriorated in 11 patients (CV=10.7–68.7 ml, mean 28.6±18.4, RD=14–26%, mean 17.8±4.5). Improvement was seen in three cases (CV=13.7–17.7 ml, mean 16±2, RD=16.5–20.1%, mean 18.2±1.8). Perfusion deterioration in areas distant from AVMs was found in nine cases, improvement in three cases.Conclusion
The changes of perfusion caused by endovascular embolization of AVM can rely on both deterioration and improvement, and occur in the parenchyma surrounding the AVM and in the distant regions of the brain. Although deterioration of perfusion indicated that more frequent follow-up was necessary, it was not related with serious complications in our group of patients.