[Positron emission tomography in the diagnosis of atherosclerotic plaques in cancer patients].

AIM: To assess the capacities of radionuclide diagnosis of atherosclerotic changes in the great vessels in cancer patients. MATERIALS AND METHODS: 18F-fluorodeoxyglucose positron emission tomography (PET) was used to image unstable atherosclerotic plaques in the aorta and great vessels. Whole-body radiodiagnostic studies were retrospectively analyzed in 500 cancer patients of different ages and with different forms of neoplasms. RESULTS: Tomographic images showed atherosclerotic plaques in 21% of the patients with the verified diagnosis of coronary heart disease (CHD) and in 17% without its clinical manifestations. CONCLUSION: The study showed it possible to identify a cardiovascular risk in cancer patients.

[Positron emission tomography in the diagnosis of recurrent growth of brain tumors].

The authors analyzed the results of 11C-methionine positron emission tomography (PET) in 101 patients with suspected recurrent brain tumor. The diagnosis was confirmed in 72 patients. The increased 11C-methionine uptake in the initial tumor area is considered to be a crucial PET evidence of a recurrent tumor. On the other hand, brain tissue histological changes associated with surgery, radiation, and chemotherapy were characterized by the low uptake of the tracer. The sensitivity and specificity of PET scanning in detecting tumor recurrence were found to be 95.8 and 96.5%, respectively. 11C-methionine PET is proposed as a reliable technique for early differentiating between a recurrent brain tumor and treatment-induced nonneoplastic changes.

[Changes of cerebral glucose metabolism in patients with multiple sclerosis and their role in formation of the clinical picture and progression of the disease]. / Izmeneniia metabolizma gliukozy golovnogo mozga u bol'nykh rasseiannym sklerozom i ikh rol' v formirovanii klinicheskoi kartiny i v progressirovanii zabolevaniia.

Multiple sclerosis is an autoimmune disease, which characterized by CNS myelin lesion. The pathological changes include distinct demyelination foci well identified by MRI. However, because their volume and localizations weakly correlate with clinical appearances and progression of the disease, functional changes may exert a greater influence on disablement indices than regular MRI data. Positron emission tomography (PET), using a labeled native glucose analogue [18F] fluorinedesoxyglucose (FDG-PET) enables to evaluate cerebral glucose metabolism and specify an association between brain metabolism and clinical appearances. FDG-PET has been administered to 87 patients: 57 with valid MS, remitted course (group 1) and 30 with primary-, remitted- and secondary-progressive course (group 2). Besides, a patient's state was evaluated with EDSS and FS scales. A regional to global activity ratio was calculated according to ICVRglu indices. In both groups, significant negative correlation between glucose metabolism in the majority of the brain regions and MS duration was found, being more distinct in group 2. Also, cerebellum metabolism reverse correlated with FS 2 scale scores. In group 2, ICVRglu index in subcortical structures positively correlated with FS 1 scores. Positive correlation between ICVRglu in somatosensor area and EDSS and FS scores was detected. The associations with PET demonstrated a relationship between clinical syndromes, MS duration and cerebral metabolism level, being mostly pronounced in the group with progressive course. Both hypo- and hyper metabolism may be clinically significant. In the patients with progressive MS, hyper metabolism in sensomotor area is likely to be of compensatory importance.

[New criteria for positron emission tomographic diagnosis of brain glioma using 11C-methionine]. / Novye kriterii v positronno-émissionno-tomograficheskoi diagnostike gliom golovnogo mozga s ispol'zovaniem 11C-metionina.

The study was based on the data of positron emission tomography (PET) and L-[methyl]-[11C]-methionine used in 117 patients with suspected brain tumor. PET data on 74 patients with histologically verified cerebral tumors were analyzed in detail. New additional criteria for assessing PET scans, which formed the PET syndromes of astrocytomas, anaplastic astrocytomas, and glioblastomas. Operative and histological verification confirmed the high validity of the proposed criteria for defining the type of a tumor.

[Positron-emission tomography in intracranial hematomas]. / Pozitronno-émissionnaia tomografiia pri vnutricherepnykh gematomakh.

Positron emission tomography by using H2(15)O whose distribution in the brain reflects a genuine cerebral blood flow was made in 5 patients with suspected intracranial hematomas. It was shown that tunicary hematomas might be diagnosed by positron emission tomography. However, examination of cerebral blood flow was not optimal in this abnormality. Computerized tomography remains the basic method for diagnosing intracranial hematomas and positron emission tomography should be used to evaluate cerebral function.

[Positron-emission tomography in the diagnosis of brain damage in patients in the late period of craniocerebral trauma]. / Pozitronno-émissionnaia tomografiia v diagnostike povrezhdenii golovnogo mozga u bol'nykh v otdalennom periode cherepno-mozgovoi travmy.

PET data were compared with the results of computerized tomography (CT) and the neurological status of patients. The areas of decreased local cerebral blood flow (LCBF) and reduced local cerebral metabolic glucose rates exceeded those of brain injury shown by CT predominantly in patients with brain posttraumatic cysts. In a group of patients with posttraumatic atrophy documented by CT, PET demonstrated cortical and/or subcortical lesions in most cases, providing objective evidence for neurological symptoms. PET is a useful technique to demonstrate regional brain dysfunction in the presence of morphological integrity as assessed by CT.