Tc-99m-HMPAO brain scintigraphy

Sixteen single photon emission computed tomography (SPECT) studies with Tc-99m hexamethyl propylene amine oxime (Tc-99m HMPAO) were performed in patients with cerebral infarction (n=10), transient ischemic attack (n=2), or brain tumor (n=3). X-ray computed tomography (CT) scans and SPECT scans with N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP) were also obtained for comparison with findings of SPECT with Tc-99m HMPAO. Crossed cerebellar diaschisis (CCD) was detected in five patients (33%) on both early and delayed SPECT scans with Tc-99m HMPAO. In 8 patients, early scans with Tc-99m HMPAO tended to depict lesions more extensively when compared with CT. Early scanning with I-123 IMP was superior to that with Tc-99m HMPAO in detecting lesions. In detecting CCD, both methods were comparable to each other. In visualizing the basal ganglion, early scans with Tc-99m HMPAO were superior to scans with I-123 IMP. Tc-99m HMPAO has the advantages of short half-life period, small amounts of exposure doses, simple labeling, and prompt usage in emergency cases, such as cerebral infarction and cerebrovascular disorder. (Namekawa, K)