Superiority of Tc-99m ECD brain SPECT to Tc-99m HMPAO brain SPECT in localizing the infarction zone in the same brains with subacute stroke

초록

Background: We investigated diagnostic performance of 99mTc-ECD brain single-photon emission computed tomography (SPECT) and 99mTc-HMPAO brain SPECT to localizing the infarction zones in the same brains with subacute strokes. Methods: We examined 49 patients using brain SPECT with 99mTc-ECD and with 99mTc-HMPAO, and magnetic resonance imaging (MRI) of the brain less than 7 days of their stroke onset. MRI showed cortical infarction in 29 patients. Split dose and sequential SPECT techniques were used for 99mTc-ECD SPECT and 99mTc-HMPAO SPECT, without repositioning of patients. Asymmetric index (AI) of infarction zones was calculated. The subtraction images of 99mTc-ECD SPECT and 99mTc-HMPAO SPECT were coregistered to MRI template. Results: Among 29 patients with cortical infarction on MRI, visual side-by-side interpretation of 99mTc-HMPAO SPECT showed hypoperfusion in infarct zones in 27 patients except two patients with infarction in occipital lobes. In these two patients, 99mTc-ECD SPECT showed hypoperfusion in the same site with cortical infarctions in one patient. In the other patient, there was no hypoperfusion on both of 99mTc-ECD SPECT, and 99mTc-HMPAO SPECT. The asymmetric index (AI; 35.0  30.0) of 99mTc-ECD SPECT was larger (p = 0.002) than the AI (17.4  20.2) of 99mTc-HMPAO SPECT. Visual side-by-side interpretation showed larger extent of hypoperfusion in infarct zones on 99mTc-ECD SPECT than 99mTc-HMPAO SPECT in 10 (34%) of 29 patients. Among these 10 patients, the subtraction images of 99mTc-ECD and 99mTc-HMPAO SPECT coregistered to MRI sowed significant lower 99mTc-ECD uptake than 99mTc-HMPAO uptake in 4 (40%) patients. Conclusions: Compared with 99mTc-HMPAO SPECT, the degrees of hypoperfusion in infarct zones was significantly larger with 99mTc-ECD SPECT in a head-to-head comparison of the same patient during subacute stroke. The subtraction images coregistered to MRI supported the visual assessment. Therefore, we suggest that 99mTc-ECD