Reliability of the evaluation of regional cerebral blood flow using SPECT in chronic schizophrenia and bipolar disorder

OBJECTS: Demonstrate the reliability of cerebral SPECT using 99 mTc-HMPAO. METHODS & MATERIALS: Evaluation of cerebral blood flow using SPECT in 24 patients with schizophrenia, 24 patients with bipolar disorder and 20 controls. In the study we have reliability between observers and intraobserver. In both cases kappa statistic has been applied for measuring reliability. RESULTS: reliability between observers represents a kappa coefficient of 0.71. Intraobserver reliability, with a medium grade concordance slightly superior, shows a medium kappa coefficient of 0.74. CONCLUSIONS: Visual evaluation of SPECT images using 99mTc--HMPAO is a trustworthy technique to document the different patterns of regional cerebral blood flow. Reliability is determinate by the improvement, during visual analysis of reliability between observers (kappa: 0.71) and intraobservers (kappa: 0.74).