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Biomedical subjects

F M Liass

Publications and source records attributed to F M Liass.

At least 19 recordsLinked to original sources
PubMed1991

[Computerized system of dosimetric planning of interstitial multiposition stereotaxic irradiation in neutron therapy of brain tumors].

A computerized system PLUT-B intended for a dosimetric design of stereotaxic neutron brachytherapy of brain tumors, was developed. It is capable of simulating dose distribution in various parameters of irradiation, manipulating them, retaining the surgical aspects within the field of vision, and arriving at an acceptable dosimetric plan. The system permits visualization of a target with an applied dose field in the multiwindow mode, layer-by-layer vision in any direction, displaying a scheme of implantation, and drawing up of maps of isodose distributions. It is intended to be used by a physician, convenient in operation, the time at the design stage is 35-40 minutes.

Brachytherapy↗
PubMed1990

[Single-photon emission-computed tomography with the Testascan multidetector gamma tomograph in neurologic practice].

The paper is concerned with the results of single-photon emission tomography and gamma-topography in patients with cerebral tumors, cerebral circulatory disorders and pathology of the liquor system. Tomographic investigation was shown to enhance the accuracy and reliability of the detection of cerebral tumors. Single-photon emission computerized gamma-tomography (SPECT) permitted the detection of structural and morphological cerebral changes in disturbed cerebral circulation of various etiology. SPECT together with computerized tomography and radionuclide cisternography was shown to be an auxiliary method for visualization of the cerebral cisterns. Radionuclide tomographic images as compared to gamma-topographic findings of the brain possessed a high statistical significance and good resolution.

Adult↗
PubMed1990

[The efficacy of gamma teletherapy in the combined treatment of medulloblastomas in the posterior cranial fossa of children].

The results of radiation therapy conducted after various schemes were compared in 77 patients operated on for medulloblastoma of the posterior cranial fossa: 1. irradiation of the posterior cranial fossa area; 2. irradiation of this area and the entire length of the spinal marrow; 3. total irradiation of the CNS. Stages in a metastatic process necessitate irradiation in stages, i.e. irradiation of the posterior cranial fossa and the length of the spinal marrow followed by irradiation of the cerebral hemispheres one year after the operation. Total irradiation of the CNS shortly after the operation is recommended only in the presence of early metastases.

Cerebellar Neoplasms↗
PubMed1990

[Single-photon emission-computed tomography of the head using labelled amines in visualizing the cerebral microcirculation].

The authors presented clinical material on cerebral hemodynamics in patients with neurological pathology in suspected tumor vascular cerebral diseases and craniocerebral traumas. Investigation of cerebral microcirculation was performed using a multidetector single-photon emission tomograph "Testoscan" (USSR) after iv administration of 99mTc-hexamethylpropilene-amyloxine. This radiopharmaceutical is good for the evaluation of cerebral perfusion and gives a clinician rich information on cerebral microcirculation.

Adult↗
PubMed1990

[Radiation dosage exposure of the population of the USSR from x-ray diagnosis and means for its reduction].

The paper is concerned with main values of dose exposure of the USSR population as a result of medical roentgenological investigations. The authors issue practical organizational-methodological recommendations for irradiation reduction resulting from giving up chest x-ray, a decrease in prophylactic fluorography, improvement of technical facilities for investigations of the digestive tract, and organization of roentgenoradiological departments as independent health service units.

Humans↗
PubMed1989

[Gamma radionuclide topography of the brain in diagnosing inflammatory processes in children and adults].

Gamma topography of the brain as a differential diagnostic method permits the recognition of an inflammatory process and specification of its localization. It can be widely used in an outpatient setting (both for children and adults). Altogether 61 patients were investigated: abscesses of the brain (36 patients, of them 16 children); focal arachnoencephalitis (14 patients, of them 5 children); arachnoiditis (11 patients). Gamma topography of the brain makes it possible to clarify early topical diagnosis of a process. Due to its simplicity, small radiation exposure and noninvasive character of the method can be recommended in outpatient clinics and hospitals both for children and adults.

Adult↗
PubMed1989

[The TESTASCAN single-photon emission multidetector computed gamma tomograph].

A TESTASCAN single-photon emission multidetector gamma tomograph is a special purpose unit designed to investigate RP distribution in the brain. It permits obtaining transversal tomographic images with the resolution of about 10 mm, the thickness of an emitted layer being about 15 mm. The time of patient's examination during obtaining an image of 10-12 layers does not exceed 30 min. and can be reduced by increasing RP activity and minimizing the number of emitted transversal sections. The clinical testing of the unit has shown that it is reliable in maintenance and simple to operate during radionuclide data collection, reproduction and analysis. Emission computerized tomography in brain tumors can be regarded as a method increasing the accuracy and reliability of radionuclide diagnostic examination of neurosurgical and neurological patients.

Brain Neoplasms↗
PubMed1989

[Radioanatomy of cerebral perfusion in single-photon emission-computed tomography using 99mTc-labelled amines].

A study was made of the cerebral hemodynamics by assessing the distribution in single-photon emission computerized tomography with 99mTc-hexamethyl-propyleneminoxyne in health using a Testascan in 9 standard slices. The whole set of tomographic slices was conventionally divided into 3 levels. For better orientation in gamma-tomographic images, pictures were presented where in addition to scintigrams a morphological scheme of the cerebral parts with the marked parts perfused by cerebral arteries, was given.

Brain↗
PubMed1989

[The place of radiotherapy in the treatment of pituitary adenomas].

The paper is devoted to an analysis of the present-day role of radiotherapy of pituitary adenomas with relation to tumor spreading and the patient's neuroendocrine status. The authors made use of data obtained from the N. N. Burdenko Research Institute of Neurosurgery, USSR Academy of Medical Sciences. They analyzed the results of gamma-beam therapy, proton-beam therapy and radiosurgical implantation of 90Y granules used alone as well as in combination with surgical intervention. Based on the analysis of the clinical data on 320 patients, a conclusion is made on the indications for one or another method depending on the stage and course of the disease.

Adenoma↗
PubMed1987

[Proton therapy in clinical neurosurgery].

The use of proton beam irradiation in neurosurgical clinical practice helps to find a solution to the problem of the treatment of inoperable malformations employing this method in some cases as an alternative to surgical intervention. Hypophyseal tumors, tumors of the cavernous sinus, arteriosinusal anastomoses in the cavernous sinus area, and arteriovenous malformations are irradiated at the N. N. Burdenko Institute of Neurosurgery, USSR, AMS using the medical proton beam of the Institute of Theoretical and Experimental Physics. Methods of "piercing" irradiation and methods with the use of Bragg's peak are being developed. At present over 200 patients with hormonally active hypophyseal tumors, 30 patients with tumors of the cavernous sinus, 23 patients with deep seated arteriovenous malformations, and 10 patients with spontaneous arteriosinusal anastomoses in the cavernous sinus area have been irradiated. This method seems to hold promise in neurosurgical practice. Extension of the range of clinical applications of proton beam therapy in neurosurgery requires the development of various techniques of irradiation, all possible approaches to various targets on the basis of contemporary methods of computerized diagnosis, topometry and irradiation design.

Brain Neoplasms↗
PubMed1986

[Gamma-topographic study of patients with pathological orbital processes].

A gamma-topographic study of the orbit was performed in 64 patients with unilateral exophthalmus using 99m Tc-pertechnetate. Some peculiarities in the RP distribution in the focus of lesion in malignant and benign neoplasms and inflammatory processes in the orbit were revealed. Correlation between RP accumulation intensity in the focus and the degree of RP vascularization and volume was shown. The method does not allow assessment of the morphological nature of a process however its use extends the diagnostic potentialities in specifying the genesis of unilateral exophthalmus and facilitates the choice of appropriate therapy.

Adult↗
PubMed1985

[Radionuclide cisternography in the diagnosis of pathology of the cerebrospinal fluid system in children].

Radionuclide cisternography (RCG) was performed in 78 children with different forms of hydrocephalus: external, internal (ventricular) and obstructive. Radiological signs were determined by spatial-time distribution of a radiopharmaceutical over the liquor pathways. Morphological and liquorodynamic disorders (liquor circulation and resorption disorders) served as a basis for the differentiation of hydrocephalus forms.

Adolescent↗
PubMed1984

[Radionuclide ventriculography in the diagnosis of hydrocephalus in children].

Using the findings of ventriculo- and cisternography with 99mDTPA performed in 30 patients, it has been shown that the signs of open hydrocephalus should be considered the following: the visualization of the lateral ventricles, the third and fourth ventricles, the great cistern and the subdural space of the cervical part of the spinal cord (in preset time intervals); RPH complete absence (even after 24 h) in the subdural space of the brain (convencital, medial and parasagittal parts). Significant radiological signs of occlusive hydrocephalus are obtained from the visualization of one or two lateral ventricles; the visualization of the third ventricle and the great cistern. CSF disturbances revealed in radionuclide ventriculography can be used for the assessment of CSF resorption as well as the stage of process (decompensated stage).

Cerebral Ventricles↗