Single photon emission CT images in a case of intraventricular neurocytoma

Imaging of the cerebrum

The history of the development of cerebral imaging is a complex combination of the forces of innovation at both the individual and industrial levels. Principal paradigms of neuroimaging shifted as a result of technological breakthroughs, beginning with the discovery of x-rays and continuing with the development of computerized imaging to the latest imaging paradigm, nuclear magnetic resonance imaging. We discuss these landmarks in neuroimaging in historical context, with emphasis on the particularly rapid development of imaging technology during the past 30 to 40 years, including the most recent emerging technologies.

201Tl-SPECT and 1H-MRS study of benign lateral ventricle tumors: differential diagnosis of subependymoma

The introduction of computed tomography (CT) and magnetic resonance (MR) imaging has resulted in the detection of increasing numbers of asymptomatic intraventricular tumors. Establishing the correct preoperative diagnosis is important to prevent unnecessary surgical intervention. Our study includes nine cases of benign lateral ventricle tumors including two cases of central neurocytoma, two of subependymal giant cell astrocytoma, two of pilocytic astrocytoma and three of subependymoma treated surgically between 1996 and 2003. MR imaging, proton MR spectroscopy ((1)H-MRS) and thallium-201 single photon emission computed tomography ((201)Tl-SPECT) were performed in all patients. All three types of tumor demonstrated heterogeneous enhancement on MR imaging with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and increased choline (Cho) peak and decreased N-acetyl aspartate (NAA) and creatine (Cre) peaks on (1)H-MRS. (201)Tl-SPECT showed high uptake of (201)Tl without wash out in all cases of central neurocytoma, subependymal giant cell astrocytoma and pilocytic astrocytoma, but no uptake in cases of subependymoma. Absence of (201)Tl uptake in contrast with enhancement on MR imaging and the (1)H-MRS features of modest elevation of the Cho/Cre ratio, reduction of the NAA peak and presence of lactate/lipid peaks are characteristic features of subependymomas and useful to establish a preoperative diagnosis.

Central neurocytoma with unusually intense FDG uptake: case report

Central neurocytoma is a benign neuronal tumor with a favorable prognosis. This tumor is typically characterized by decreased uptake of 18F-fluorodeoxy glucose (FDG) and any increased uptake of FDG in patients suffering from this tumor would be highly unusual. A case of central neurocytoma with an intense FDG uptake, combined with atypical histopathological features and a high proliferation index is reported in this paper. A 45-year-old male had a two months' history of right hemiweakness. Magnetic resonance (MR) imaging showed a large tumor in the right lateral ventricle. Positron emission tomography (PET) with FDG revealed high glucose metabolism in the tumor. The histological diagnosis was central neurocytoma with atypical features characterized by microvascular proliferation. The MIB-1 labeling index, ordinarily smaller than 2.0%, was 7.0%. Conventional radiotherapy, with a total dose of 50 Gy, was administered after the surgical treatment. The patient returned to his normal daily activities after the cessation of radiation therapy.