The value of eZIS analysis of Tc-99m ECD SPECT on identifying cerebellar hypoperfusion in a patient with superficial siderosis

INTRODUCTION Brain perfusion single photon computed tomography (SPECT) is a functional imaging modality and has been widely utilized in evaluation of various kinds of neurological disorders. Easy z-score imaging system (eZIS) is a computer-assisted statistical analysis, based on the comparison with age-classified ethyl cysteinate dimer (ECD) normal database, which provides objectively interpretation of Tc-99m ECD brain perfusion SPECT.Here we presented a 64-year-old male with dizziness, spin sensation, nausea, and vomiting in the emergency room, and brain computed tomography scan showed only small hypodensity lesion in cerebellum. Tc-99m ECD SPECT was performed for evaluating occult cerebral ischemia, infarction, and/or degeneration, but no remarkable abnormality could be identified by experienced readers on conventional display. The result of eZIS showed remarkable hypoperfusion in cerebellum and mild hypoperfusion in bilateral frontal and parietal lobes. Magnetic resonance imaging (MRI) confirmed severe atrophy of anterior cerebellar lobe. In addition, MRI showed diffuse hypointensity signals along with cerebrospinal fluid spaces, especially those areas with hypoperfusion on SPECT, compatible with typical appearances of superficial siderosis. CONCLUSION This presented case demonstrates the value of software analysis with eZIS on enhancing the diagnostic value of brain perfusion SPECT for detecting brain lesions at an uncommon location due to a rare disease.