~(201)Tl and ~(99)Tc~m-HMPAO SPECT IMAGING IN BRAIN LESIONS

摘要

Eighty-five patients with three different types of brain lesions were included in the study. Twenty-five patients with malignant astrocytoma, either post-operatively (15 cases) or with recurrent tumour versus gliosis (10 cases), were studied using ~(201)Tl SPECT (single photon emission computed tomography). Calculation of early delayed uptake and the retention index showed high early late uptake with low retention index in high grade astrocytoma versus a low mean value of early and delayed uptake with a high retention index in low grade glioma. Also, recurrent cases showed remarkable differences in early and delayed ~(201)Tl uptake (P < 0.05) and retention index (P < 0.001). Compared with post-radiation gliosis, there was greater sensitivity in the detection of tumour viability using ~(201)Tl SPECT (100%) versus 80% using computed tomography (CT) scanning. Furthermore, 30 patients with interictal epileptic fits were evaluated with ~(99)Tc~m-HMPAO (hexamethylpropylene amine oxime), electroencephalogram (EEG) and CT, with sensitivities of 80, 73.3 and 20%, respectively. The third group of 30 patients with different onset of cerebrovascular stroke was evaluated with ~(99)Tc~m-HMPAO. They showed larger lesions in both the acute phase (8 patients) and the subacute phase (12 patients) compared with CT scanning. Also, crossed cerebellar diaschiasis was seen in 50% of each group and 'luxury' perfusion in 30% of the subacute phase. Additional lesions with signs of cerebral atrophy in 75% of acute and 50% of subacute phases were noted. A similar finding was noted for ~(99)Tc~m-HMPAO and CT scanning in ten patients in a chronic phase with no evidence of other lesions, cerebellar diaschiasis, or signs of cerebral atrophy.