Thallium-201 single-photon emission computed tomographic and proton magnetic resonance spectroscopic characteristics of intracranial ganglioglioma: three technical case reports.

Abstract

The correlation between thallium-201 (201TI) uptake, semiquantitative choline-containing compound values measured by proton magnetic resonance spectroscopy (1H-MRS), and Ki-67 labeling indexes (LIs) was investigated in three gangliogliomas. The early and delayed 201TI indexes were calculated as the ratio of tumor to normal brain tissue uptake by 201TI single-photon emission computed tomography. Single-voxel 1H-MRS was performed to measure the levels of metabolites in the tumors. Ki-67 LI was measured in the surgical specimens. All three gangliogliomas showed very high 201TI uptake on both early and delayed images. 1H-MRS demonstrated malignancy based on the high choline peak relative to the creatine and N-acetylaspartate peaks. Ki-67 LI was less than 1% in two gangliogliomas and 3.5% in an anaplastic ganglioglioma. Both 201TI single-photon emission computed tomography and 1H-MRS indicated malignancy, whereas Ki-67 LI indicated low growth activity. 201TI single-photon emission computed tomography and 1H-MRS of ganglioglioma might be affected by metabolic characteristics other than growth activity.