Long-term change in size of cerebral infarction: predictive value of brain perfusion SPECT using statistical...

A focus of infarction is surrounded by hypoperfused areas. The present study was undertaken to examine the long-term changes in the size of infarcts, the relationship between the size of an infarct and the extent of the surrounding hypoperfused areas, and the background of such changes. The subjects of this study were 11 patients with ischemic lesions of the brain who had undergone brain SPECT ((99m)Tc-ethyl cysteinate dimer) within 1 week after initial MRI, and who underwent MRI again more than half a year later. Statistical parametric mapping (SPM) was conducted to detect significantly hypoperfused areas on the SPECT images. Relative size of significantly hypoperfused areas on SPM and infarcts on T(2)-weighted MR images were measured. The patients were divided into two groups based on the percentage of the infarct's size relative to the size of the surrounding hypoperfused areas (75-125 and 0-39%). Infarcts in the '75-125%' group showed little change in size, while in the '0-39%' group infarcts increased slowly until it reached the same rate as the former group. All patients with infarct in the '0-39%' group were noted to have severe stenosis of the internal carotid arteries bilaterally. Patients having severe stenosis of the internal carotid artery often had a slowly enlarging infarct. SPM seems to be useful in predicting the ultimate size of the infarct.