A discrepancy between Tc-99m HMPAO SPECT and Tc-99m ECD SPECT in Creutzfeldt-Jacob disease.

We observed a discrepancy between the perfusion patterns seen in single photon emission computed tomography (SPECT) images obtained using technetium-99m hexamethyl propylene amine oxime (HMPAO) and SPECT images obtained using technetium-99m ethyl cysteinate dimer (ECD) in an 84-year-old man with Creutzfeldt-Jacob disease (CJD). HMPAO-SPECT demonstrated a reduction in perfusion in the parieto-temporal regions, especially the left temporal area. However, ECD-SPECT revealed a significant reduction in the bifrontal regions. At autopsy, the characteristic pathological findings of CJD, spongiform vacuolation, were most prominent in the bifrontal regions. Thus, the clinical features and the pathological findings were more closely correlated with the ECD-SPECT images than the HMPAO-SPECT images.