Early and delayed brain SPECT with technetium-99m-ECD and iodine-123-IMP in subacute strokes.

Abstract

The brain distribution of 99mTc-ECD versus 123I-IMP was compared in patients with subacute stroke in order to compare diagnostic accuracy. A total of 25 patients with subacute stroke underwent early and delayed SPECT imaging with 99mTc-ECD and 123I-IMP. Washout of 99mTc-ECD was calculated and a differential percentage of activity (DPA) of ischemic versus normal zones was assessed. Images were analyzed twice by five independent observers. Technetium-99m-ECD clearance was 12.5% from the whole brain during early imaging. Ischemic parietal zones had higher clearance than normal parietal zones. Technetium-99m-ECD images showed larger differences between abnormal and normal brain activity than 123I-IMP images. Detection accuracy was slightly, but not significantly, higher for 99mTc-ECD and 123I-IMP (sensitivity: 73.8% as 66.6%; specificity: 81.7% as 81.6%). Reproducibility among observers was similar for 99mTc-ECD and early 123I-IMP. Technetium-99m-ECD demonstrates high diagnostic accuracy during subacute stroke, similar to 123I-IMP, but with more intense, better delineation of the perfusion defects.