The diagnostic difference between 18F- FDG PET and 99mTc-HMPAO SPECT perfusion imaging in assessment of Alzheimer's disease

Brain imaging with F-18 fluorodeoxyglucose (18F-FDG) positron ýemission tomography or Tc-99m hexamethylpropyleneamine oxime (ý99mTc-HMPAO) SPECT is widely used for the evaluation of Alzheimer's ýdementia (AD); we aim to assess superiority of one method over the ýother.
Twenty four patients with clinical diagnosis of Alzheimer disease ýunderwent 18F-FDG PET and ý99mTc-HMPAO SPECT in order to ýassess the zones of hypo metabolism & hypoperfusion specific for ýAlzheimer's disease.
18F-FDG PET showed specific zones of ýhypometabolism in 19 patients (79.1%) while SPECT was positive in 15 ýcases (62.5%) with statistically significant difference (P= 0.027).
18F-FDG PET was significantly superior to HMPAO ýSPECT and 18F-FDG PET could replace the classic role of perfusion ýSPECT in diagnosis of Alzheimer's disease.