Abstract
Three dimensional tomographic images of local cerebral blood flow (1CBF) using single photon emission computed tomography (SPELT) were obtained with N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) and 133Xe in 19 subjects: seven with ruptured aneurysm, one with unruptured giant aneurysm, five with arteriovenous malformation (AVM), six with moyamoya disease. This study concerned a comparison between the two methods of 133Xe inhalation and 123I-IMP intravenous injection. Clinical and morphological (angiography, CT scan) findings were used for reference.
The SPECT image showed low 1CBF earlier and larger than CT scan abnormalities in patients with cerebral vasospasm following subarachnoid hemorrhage. 133Xe 1CBF images showed high flow areas in giant aneurysm and nidus of AVM but 123I-IMP SPECT showed decreased activity in these areas. Low activity area with 123I-IMP around the large AVM may indicate an intracerebral steal phenomenon or decreased metabolism. In the patients with moyamoya disease, CT scan demonstrated minimal changes, but large areas of decreased 1CBF were demonstrated with both 133Xe and 123I-IMP. The patients with intracerebral hematoma had a definite defect area of 1CBF corresponding to the hematoma on CT scan and a large area of decreased activity around the hematoma.
133Xe ICBF and 123I-IMP SPECT maps correspond well with each other under certain conditions, but they differed in the points of spatial resolution and true nutritional blood flow. 123I-IMP may give an image of other functions more important than cerebral blood flow.
