Tc-99m HMPAO/SPECT determination of regional cerebral blood flow changes in schizophrenics

Hypofrontality (hypometabolism and hypoperfusion) has been demonstrated in patients with schizophrenia by the use of several imaging methods, such as positron emission tomography (PET). In this study, Tc-99m hexamethylpropylene amineoxime (HMPAO) and SPECT were used to investigate regional blood flow changes in 20 schizophrenic patients (12 males and 8 females, aged 15-50 years) experiencing acoustic hallucinations. Tc-99m HM-PAO (15-20 mCi) was injected intravenously, eight regions/hemisphere were drawn on transaxial sections, and tracer redistribution was calculated for each region. Frontal/occipital ratios (0.917 +/- 0.045) and frontal/whole-slice ratios (0.984 +/- 0.036) were determined for each patient. The patients had significantly lower frontal/occipital ratios (P less than 0.0005) and lower frontal/whole-slice ratios (P less than 0.01) in comparison to a normal group (11 cases).