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Biomedical subjects

A V Golanov

Publications and source records attributed to A V Golanov.

At least 19 recordsLinked to original sources
PubMed1994

CT-guided computer-assisted stereotactic resection of brain tumours.

A computer-assisted technique was developed for CT-guided stereotactic microsurgical resection of small intracerebral lesions. An original stereotactic retractor was developed to work with the Riechert-Mundinger's equipment for precise localisation, safe exposure and microsurgical removal of these tumours. A software-program was developed to work on an ordinary IBM-compatible PC/AT. It assisted the procedure from treatment planning till the end, including tumour excision, and provided computerized support for the removal of pathological tissues within the CT-defined boundaries of the lesion. 6 patients, harbouring supratentorial intracerebral lesions underwent surgery using this technique. 2 of them suffered from brain metastases, in 1 patient a cavernous angioma was removed, 2 patients had glial tumours, and in the last patient only radiation necrotic tissue was found to be the cause of ring-enhanced lesion, which had been suspected to be a recurrent glioma. Their largest dimensions varied between 18 and 30 mm and the age of the patients ranged from 15 to 52 years. In 2 cases the lesions were localised deeply in the region of basal ganglia and thalamus. In the remaining patients the tumours were rather superficial, infiltrating subcortical white-matter close to the central sulci. There was no mortality nor significant morbidity following the procedure, the Karnofsky Performance Status (KPS) cumulative scores being either unchanged (in 3), or improved (in 3 patients). Current state and modern concepts in image-guided open stereotactic methodology is discussed.

Adolescent↗
PubMed1993

Functional neurosurgery using 3-D computer stereotactic atlas.

To facilitate a full-scale representation of thalamic nuclei and surrounding subcortical structures in the course of stereotactic procedures, a 3-D computer atlas of this region has been created, which permits visualization of the operative field including the involved structures and the position of the instrument. Necessary adaptation is performed according to the position of the intracranial reference points derived from CT-scan. Working with the atlas permitted more accurate and safer surgery. An IBM PC/AT computer was used.

Adult↗
PubMed1991

3-D computer model of subcortical structures of human brain.

Three-dimensional computer model of thalamus and adjacent formations of human brain has been elaborated on the basis of sagittal slices from the Schaltenbrand-Bailey stereotactic atlas. The model includes 120 morphologically distinguishable structures and consists of more than 16 million points (volume elements) each of them being associated with the particular structure in the brain. The model is stored in the long-term computer memory. A special software has been developed to facilitate utilizing the model obtained. The software facilitates synthesizing arbitrary cross-sections through the brain and provides the correspondence between the stereotactic coordinates of any point and its position on the screen of monitor. The coordinates of the point in the system of stereotactic atlas and the name of the structure, the point belongs to, are also supplied. It is also possible to get magnified images of cross-sections and to get isometrical images. The system enables the neurosurgeon to improve the planning and execution of stereotactic operations, and will also be helpful for education.

Brain↗
PubMedDate not supplied

[The prognostic importance of cancer-associated proteins and apoptosis in glioblastomas of the cerebral hemispheres].

Clinical and morphological studies were undertaken to examine 168 patients with glioblastomas of the cerebral hemispheres. They revealed that the longevity of the hemispheres was substantially influenced by three immunobiological criteria: the proliferative potential defined as a labelling index (LI) of proliferative cell nuclear antigen (PCNA), the expression of intracellular domain of epidermal growth factor receptor (EGFR) and the rate of apoptosis identified by ISEL. The risk for shorter survivals increases with higher PCNA LI and with the EGFR expression in the tumor. In contrast, the rate of apoptosis is a good predictor since the risk for shorter postoperative survivals progressively reduces with high apoptotic indices. The expression of cancer proteins p53 and bc12 in the glioblastomas produces no noticeable effect on the patients survival.

Adolescent↗
PubMedDate not supplied

[Diffusion-weighted image in the study of brain tumors and peritumoral edema].

The informative value of the technique of diffusion-weighted images (DWI) and diffusion maps was studied in diagnosing supratentorial tumors of the brain. Sixty four patients were examined. Among them there were 35 patients with glial brain neoplasms of varying malignancy [benign astrocytomas (asc) in 15 patients, anaplastic asc in 10, and glioblastomas in 10)], 15 patients with meningiomas, 5 with hydrocephalus, 9 with cerebral circulatory disorders. To obtain DWI, diffusion-weighted echo-planar impulse sequence was used. ADC was within (1.52 +/- 0.34) x 10(-3) mm2/sec for fibrillary astrocytomes. The anaplastic astrocytoma group showed variations in ADC values: ADC was higher in the contrasted part of the tumor than in the non-contrasted one and averaged (1.23 +/- 0.32) x 10(-3) mm2/sec. Glioblastomas were also noted for a higher variation in ADC that averaged (1.18 +/- 0.29) x 10(-3) mm2/sec. Meningiomas had a greater MR signal in response to DWI and low ADC values [(0.97 +/- 0.17) x 10(-3) mm2/sec]. Particular emphasis is laid on the study of different types of brain edema. ADC in the area of vasogenic (peritumoral), cytotactic (ischemic), and interstitial edema was (1.30 +/- 0.11) x 10(-3), (1.04 +/- 0.05) x 10(-3), and (1.91 +/- 0.1) x 10(-3) mm2/sec, respectively (p < 0.05) and sharply distinct in ADC maps.

Adolescent↗
PubMedDate not supplied

[Proliferative markers of meningiomas: immunohistochemical analysis and prognostic value].

Routine pathological examination cannot precisely predict the clinical course of meningiomas because even histologically benign tumors may recur after total removal. And so, numerous efforts have been made for evaluation of meningioma growth fraction and its prognostic value. In this study the prognostic significance of DNA toposiomerase II alpha (topoII) and cyclin A immunohistochemistry was examined in a series of 263 meningiomas. The topoII and cyclin A scores exhibited a close correlation with Ki-67 immunostaining. Significant differences between the indices for all the three markers were noted among the three grades of meningiomas. The scores for all the three markers were significantly different between recurrent and non-recurrent meningiomas including removed benign tumors. The most important information for an individual clinical outcome of histologically benign meningiomas should be elicited from simultaneous evaluation of all the three proliferative markers.

Adult↗
PubMedDate not supplied

[Complex MR-diagnosis of brain abscesses].

Early diagnosis of brain inflammatory lesion is a basic factor in choosing treatment policy. The paper investigates the use and informative value of diffuse-weighed magnetic resonance imaging in the differential diagnosis of brain abscesses and processes of another origin. It also considers the application of MR spectroscopy and perfusion MRI to obtain additional information on an inflammatory processes. A series of observations covered 10 patients with brain abscesses at different sites. Diffusion-weighed image (DWI) revealed a drastic increase in a MR signal from the central abscess portions (a pyonecrotic area), which is suggestive of decreased diffusion of water molecules. The measured diffusion ratios (MDRs) were significantly lower in the central abscess area (p < 0.005) than those in the capsule and white matter of the brain at all values of the diffuse factor b (500, 1000 sec/mm2); the capsule was better visualized at the DWI at b = 500 sec/mm2. In addition, MDRs were significantly different within the annular contrasting area of abscesses and glioblastomas, in the abscess/tissue capsule, and edema (p < 0.01). Proton spectroscopy of the central abscess area (pus) revealed succinate, acetate, alanine, peaks of lactate and amino acid. Perfusion MR study (bolus contrasting and estimation of the tissue parameters rCBV and MTT) has indicated that the central abscess in relation to the medulla is a decreased perfusion area; perfusion in the abscess capsule is close to that in the medulla in its characteristics, but medullary time in this area is shorter than that in brain tissues; perifocal edema is also characterized by hypoperfusion. The analysis of complex MRI study in patients with brain abscesses has demonstrated that diffuse-weighed MRI enhances diagnostic specificity, diagnoses the development of a pyonecrotic abscess center at early stages of capsule formation; MR spectroscopy is an additional method of differential diagnosis of brain abscess and processes of another nature whereas perfusion MRI provides additional information on medullary hemodynamic changes.

Adult↗
PubMedDate not supplied

[The CT-stereotaxic neutron brachytherapy of brain tumors with californium sources on the ANET-B apparatus].

A method for stereotaxic intratissue radiotherapy of brain tumors based on the findings of computed tomography is described. Radiosurgical implantation of sources with increased 252Cf content emitting mixed neutron + gamma-radiation was accomplished by means of an ANET-B apparatus by the afterloading method. Neutron irradiation is particularly effective in patients with malignant tumors possessing a large fraction of cells in a state of deep anoxia. Dosimetric planning was conducted by means of an original computer system. Devices and radiation-technical equipment for adaptation of the ANET-B apparatus for irradiation of neurosurgical patients are described. The indications for the use of this method and its place among the complex of measures for the treatment of patients with new growths of the brain are discussed. The first experience in using CT-stereotaxic neutron brachytherapy with californium sources on the ANET-B apparatus for the treatment of 6 patients with malignant glial tumors of the brain is dwelt on.

Adult↗
PubMedDate not supplied

[Postoperative assessment of the efficiency of the radical removal of glioblastomas in the cerebral hemispheres].

The paper analyzes the capacities of computed tomography (CT) and magnetic resonance imaging (MRI) in the postoperative period to evaluate the efficiency of surgical removal of the most malignant type of gliomas of the cerebral hemispheres. A total of 45 patients with different histological forms of cerebral hemispheral gliomas were examined, 37 of them with glioblastomas. Comparison of the results obtained by CT and MRI within the first 24 hours indicated that the latter was of greater informative value in all cases. At the same time only the use of a strict methodological approach to postoperatively estimating the remaining portions of glioblastomas makes it possible to apply these two methods as objective criteria for evaluating the efficiency of removal of a glioblastoma and hence the efficiency of subsequent therapeutic protocols. Contrast-enhanced MRI may be regarded as the method of choice in the primary assessment of patients with suspected recurrent glioblastoma.

Brain Neoplasms↗
PubMedDate not supplied

[Aspergillosis of the central nervous system (clinical observation and review of literature)].

Aspergillosis of the central nervous system presents a challenge faced with the problems arising from the establishing the diagnosis, the low efficiency of treatment, and high mortality rates (about 95% as shown by some data). This paper presents a clinical case of a patient with aspergillosis-induced central nervous system lesion verified by autopsy. Possible errors in the diagnosis and treatment of the patient are analyzed. The literature data including clinical cases, etiopathogenesis, and clinical manifestations and its possible complications are presented. Groups of patients at risk for invasive aspergillosis are considered. The paper gives the data available in the foreign literature on the methods and efficiency of treatment and mortality rates in different groups of patients. The urgency of the problem in the diagnosis and treatment of cerebral aspergillosis rises with the increased number of patients with immunological disorders due to infectious diseases (HIV), social (drug addiction, alcoholism), environmental, and other factors.

Adult↗
PubMedDate not supplied

[Neuronal heterotopy].

The diagnosis of most volumetric processes of the brain presents no difficulty today; however, there are a number of brain diseases whose clinical manifestations are similar to those of tumors. Despite the development of neurovisualization techniques (application of currently available computer and magnetic resonance tomographs and special programs, such as MR imaging and CT spectroscopy, diffusion and perfusion, etc.), some of these processes are difficult to differentiate from neoplasms noninvasively. It is evident that treatment policy should be quite different in these or those cases. Neuronal nodular heterotopy (ectopy) may be considered as one of such pseudotumorous processes. This case illustrates the rare abnormality that has the clinical and X-ray picture similar to that of neoplasms of the brain. Current noninvasive method do not always allow one to significantly verify the nature of brain tissue changes, which shows it necessary to use CT-stereotactic biopsy in some cases.

Adult↗
PubMedDate not supplied

[The CT-stereotaxic biopsy of brain tumors].

CT-stereotaxic biopsy is a modern method for the diagnosis of intracranial tumors. The histological diagnosis established by means of it makes it possible to choose the most rational tactics of treatment and determine more exactly the indications and contraindications for the operation. The examination was conducted on 219 patients with various brain tumors. Authentic histological information was obtained in 84% of cases, 4 patients died, a stable neurological defect developed in another 2 patients. Some methodical procedures for increasing the informativeness and reducing the risk of complications are discussed. An important component is rapid examination of part of the bioptic material by means of smears for intraoperative appraisal of its representativeness and correction of biopsy targets. Among 73 cases in which smears were examined only in 9 the findings were in disagreement with the data of the traditional histologic study, only in the degree of tumor differentiation in all of them. Stereotaxic biopsy is most expedient in situations in which the tactics and main method of treatment are determined to a greater degree by the histological structure rather than by the localization and the patient's general condition. Such cases account for one fourth of all cases of intracerebral tumors.

Adolescent↗
PubMedDate not supplied

[CT-stereotaxic punctures, aspiration and drainage of deep space-occupying processes in the brain (cystic tumors, hematomas and abscesses)].

The article analyses the clinical material concerning 68 patients with various deeply-seated space-occupying processes of the brain (cystic tumors, multiple abscesses, intracerebral hematomas) which were subjected to stereotaxic aspiration on the basis of the findings of computed tomography (CT-stereotaxic punctures). A significant and immediate effect with rapid regression of local and general cerebral symptoms was recorded in 38 patients with cystic intracerebral tumors and craniopharyngiomas. All the patients tolerated the operation well and in none of them were complications encountered. The precision, reliability and safety of CT-stereotaxic punctures--is the basis for such operations as intra-tissue beta-therapy of craniopharyngiomas with radiocolloids, evacuation of intracerebral hematomas, and drainage of multiple brain abscesses. Being an obvious palliative surgical measure, CT-stereotaxic aspiration of deeply-seated cystic tumors is a method of choice in cases in which a direct operation is contraindicated and in patients who are in a grave condition.

Adolescent↗
PubMedDate not supplied

[Results of surgical treatment in patients with neurocytomas of the brain].

Central neurocytoma (CN) is a rare brain neoplasm which is characterized by certain clinical, radiological, and morphological characteristics. This tumor was first described in 1982 by J. Hassoun et al. who found neurosecretory granules and microtubules while microscopically studying 2 patients with oligodendrogliomas of lateral ventricles and concluded that these neoplasms were of neuronal origin. Materials and methods. In 1992 to 2004, a total of 84 patients diagnosed as having CN were treated at the Academician N. N. Burdenko Research Institute of Neurosurgery, Russian Academy of Medical Sciences. In most cases, the tumor showed a clinical picture as elevated intracranial pressure that was detected in 80 (more than 90%) cases. In this series, all neurocytomas were located in the ventricles, mainly in the pellucid septal region; tumor infiltration of the lateral ventricular ependyma and medullary substance invasion into the region of the thalamus and corpus callosum. Computed tomographic scans displayed central neurocytomas as space-occupying lesions of mixed (heterogeneous) density, which frequently contained single and multiple petrificates and cysts. TI-weighted magnetic resonance imaging (MRI) indicated that in most cases (n=56, 66%), the intensity of a signal from the tumor was mixed and similar to that of the white matter of the brain. These masses were characterized by the presence of tumor structural cysts that were better visualized on T2-weighted tomograms. The tumor was removed in 83 cases; 2 out of them had previously undergone stereotactic biopsy (STB). STB was performed alone in one case. Transcallous, transcortical-through-premotor-area, combined, and transcallous-transcortical approaches were applied when the neurocytomas were removed. Results. Total removal of a tumor (when its remains were not visualized by postoperative MRI) was achieved in 11 (13%) patients. Its subtotal removal was accomplished in 48 (58%) patients. Partial removal was done in 24 (29%) patients. In the early postoperative period after tumor removal, there was a worse health status along with a transient progression of cerebral and focal symptoms in most patients with CN. The magnitude, pattern, and duration of these changes differed. Conclusion. The long (from several months to several years) history of the disease and young age (14 to 59 years) are typical of patients with CN. The tumors are located intraventricularly, more commonly along the midline, and they have well-defined X-ray signs: these are well-circumscribed tumors of heterogeneous density, which frequently contain single and/or multiple cysts and petrificates; there is a moderate contrast enhancement. The basic way of improving the results of treatment in patients with CN is the latter's early diagnosis and surgery when the tumor is locally advanced within the ventricular system.

Adolescent↗
PubMedDate not supplied

[The use of hyperventilation for improving the visualization of glial tumors of the brain in magnetic resonance tomography using the contrast substance Gd-DTPA].

This study was undertaken to evaluate the influence of hyperventilation (HV) as a test on the image contrast of brain glial tumors in enhanced magnetic resonance (MR) imaging. HV was performed for 2 min (30 breaths/min) before intravenous injection of Gd-DTPA (Magnevist), Schering AG, Germany, in a dose of 0.1 mmol/kg. A total of 19 patients with glial tumors of the brain were examined. After the functional test, the image contrast of tumor tissue was compared with tumor contrast after the standard enhanced MR imaging. Nineteen patients with brain tumors were assessed. The tumor types were histologically verified in all cases (nine malignancy degree I-II astrocytomas, six malignancy degree III astrocytomas, three ependymomas, one malignant oligodendroglioma). MRI was performed on a Magnetom 42 SP-1.0 T. There was an increase in the image contrast of degree I-II astrocytomas neither after the standard enhanced MRI nor after it in the presence of HV. On the contrary, in 2 cases there was an opposite effect--the tumor contrast decrease after the functional test. Ependymomas showed patterns of increases in contrast intensity from 10 to 13% as compared with the enhanced standard MRI in all cases. In these conditions the intrinsic structure and boundaries of tumors became more distinguished. Cases with malignant astrocytomas and oligodendroglioma had contrast enhancement increases as well. It is concluded that in cases with degree I-II astrocytomas, the use of HV does not improve the visualization of lesions. In ependymomas and anaplastic astrocytomas, HV aids in more significantly assessing the intrinsic structure and the extent of tumorigenesis and it may be useful as a functional test to assess the anaplastic extent of glial tumors of the brain and as a procedure enabling the contrast agent to be used in smaller dosages.

Astrocytoma↗