[Clinical evaluation of 99mTc ethyl cysteinate dimer SPECT in patients with spinocerebellar degeneration; comparison with cerebral blood flow determined by PET].

Technetium-99m ethyl cysteinate dimer (99mTc-ECD) is regarded as a promising radiopharmaceutical for imaging regional cerebral blood flow (rCBF). We evaluated 99mTc-ECD SPECT comparing with rCBF images obtained by PET in 12 patients with spinocerebellar degeneration (SCD). SPECT images of 99mTc-ECD demonstrated characteristic findings of decreased rCBF in bilateral cerebellar hemisphere and almost identical with PET rCBF images in all patients based on the visual inspection. Semiquantitative analysis by drawing 14 intracranial regions of interest on SPECT and PET images revealed linear correlation between 99mTc-ECD count and rCBF measured by PET even in relatively high rCBF regions. In summary, 99mTc-ECD is a promising tracer for evaluating rCBF in patients with SCD and distribution of it correlates well with rCBF measured by PET.