[Role of positron emission tomography in the hemodynamic evaluation of brain tumors].

The review analyzes the literature on the use positron emission tomography (PET) with various radiopharmaceuticals in the assessment of cerebral blood flow, perfusion, the blood-brain barrier in order to investigate the biological properties, diagnosis, differential diagnosis, staging of brain neoplasms and in the evaluation of the efficiency of their treatment. The main qualitative perfusion and cerebral blood flow indicators that can be identified by PET are described in detail and compared with morphological criteria for estimation of angiogenesis and the degree of tumor tissue vascularization.

[Differential diagnosis of brain gliomas by positron emission tomography using various radiopharmaceuticals].

OBJECTIVE: To comparatively study the diagnostic capabilities of positron emission tomography (PET) with various tumorotropic radiopharmaceuticals (TRPs) in detecting malignant brain gliomas (BG) and estimating their degree. MATERIAL AND METHODS: One hundred and fourteen patients, including 47 with histologically verified glioblastoma multiforme (GBM), 27 with anaplastic astrocytoma (AA), 23 with benign astrocytoma (BA), and 17 with postoperative cysts, were examined. PET was performed using TRPs: 18F-fluorodesoxyglucose (18F-FDG), 11C-sodium butyrate (11C-SB), 11C-L-methionine (11C-MET), and 11C-choline (11C-COL). RESULTS: Malignant gliomas (GBM and AA) were clearly visualized by PET using 11C-MET, 11C-CHOL, and 11C-SB. 18F-FDG PET visualization of tumors was difficult because of increased RP accumulation in the cerebral cortex. WHO grades II-III gliomas were completely visualized by 11C-MET PET. Only some tumors were clearly displayed by PET with 11C-CHOL and 11C-SB. The accumulation indices (AI) obtained by 11C-CHOL PET in patients with malignant gliomas were, on average, 4.0- and 5.5-fold higher than those by 11C-MET and 11C-SB PET, respectively. Significant differences (p < 0.001) in AI obtained by "C-CHOL ("C-CHOL-AI) PET were first established between the patients with GBM (WHO grade IV) and those with AA (WHO grade III). CONCLUSION: 11C-CHOL PET is the most sensitive method to identify gliomas and estimate their grade. The advantage of 11C-MET PET is the possible imaging of the entire volume of viable tumor tissue.

[MRI with dynamic contrast enhancement in brain tumors].

Magnetic resonance imaging (MRI) is the leading method of radiation diagnosis of brain tumors. In conditions of the artificial contrast enhancement there are more clearly differentiated the boundaries of the tumor node on the back of peritumorous edema and identified structural features of the tumor. The purpose of this study was to examine indicators of the dynamics of accumulation and removal of contrast agents by brain tumors in MRI technique with dynamic contrast and identify opportunities of this method in the differential diagnosis of various types of tumors.

[Magnetic resonance tomography using the contrast preparation Magnevist]. / Magnitnaia rezonansnaia tomografiia s ispol'zovaniem kontrastnogo preparata magnevist.

The diagnostic possibilities of magnetic resonance tomography (MRT) using the contrasting agent magnevist were assessed by the examination of 282 patients with diseases of various organs and systems. The findings suggest that the contrasting agent magnevist shows its highly diagnostic efficiency particularly in central nervous diseases, among them there are tumors, multiple sclerosis, some vascular abnormalities and cerebral circulatory disorders. The agent used in MPT is also highly effective in identifying diseases of the liver (tumors, cysts), uterine (tumors), prostate (tumors). The valuable diagnostic information was obtained while detecting skeletal and soft tissue tumors and aseptic necrosis of the head of the femur.