Cerebral-perfusion-based single-photon emission computed tomography (SPECT) staging using NeuroGamA® in patients with moyamoya disease

Cerebral angiography (CA) is the gold standard for moyamoya disease (MMD) staging and diagnosis, but CA findings are not well correlated with clinical symptoms. The purpose of this study was to establish novel cerebral-perfusion-based staging for MMD that is well correlated with clinical symptoms. From 2010 to 2015, regional cerebrovascular reserve (rCVR) was examined by single-photon emission computed tomography (SPECT) using NeuroGamA (R) (Segamicorp, Houston, TX, USA) in 30 patients (17 women, 13 men; 60 hemispheres; mean 42.0 years old [range 5-60 years old]) with MMD, which was diagnosed by CA and magnetic resonance angiography (MRA). Brain CT or brain magnetic resonance imaging (MRI) was used to evaluate neurological conditions such as transient ischemic attack (TIA), cerebral hemorrhage, and cerebral infarction. A novel staging system for MMD was developed by combining findings from CA, MRI, and SPECT with NeuroGamA (R). Our novel staging system was strongly associated with clinical symptoms. Twenty-two hemispheres out of 60 were categorized as stage I, 24 hemispheres were categorized as stage II, and 14 hemispheres were categorized as stage III. Hemispheres with higher scores exhibited a higher incidence of clinical symptoms. These findings indicate that cerebral-perfusion-based staging is predictive of MMD clinical symptoms. Perfusion-based SPECT staging correlates well with clinical symptoms and may be a reliable alternative to the Suzuki staging by CA.