[Ultrasonographic control of cerebral blood flow in patients with stenosis of brachiocephalic arteries before and after carotid endarterectomy]. / Ul'trazvukovoi kontrol' mozgovogo krovotoka u bol'nykh so stenozom brakhiotsefal'nykh arterii do i posle karotidnoi éndarteréktomii.

The authors studied the parameters of arterial and venous blood flow in patients presenting with haemodynamically significant atherosclerosis of the carotid arteries before and after carotid endarterectomy, as well as while carrying out functional tests. Comparing the indices of arterial blood flow in the Study Group consisting of 52 patients and the Control Group comprising 15 apparently healthy volunteers at rest prior to the operation revealed statistically significant differences of volumetric parameters of blood flow in the internal carotid artery. The obtained results showed that the breath-holding test was accompanied and followed by increased velocity of blood flow in the middle cerebral artery (MCA) on the side contralateral to stenosis, with the reactivity index (RI) amounting to 0.98±0.20, which statistically significantly differed from the RI in the Control Group patients (1.28±0.13). The forced respiration test demonstrated a decrease in the volumetric indices of blood flow in the MCA on the side of stenosis, as well as an increase of the maximum end-diastolic velocity of blood flow on the side contralateral to stenosis. The test with sublingual administration of nitroglycerin appeared to result in reduced blood flow in the MCA. The supratrochlear test demonstrated decreased velocity of blood flow in the supratrochlear artery. Studying the venous link of cerebral vessels after the operation showed that statistically significant differences were revealed only on the side contralateral to stenosis as compared with the values prior to revascularization. An increase of blood flow in the internal jugular veins after the operation on the side contralateral to the operation was apparently suggestive of an adequate distribution of blood flow through the main vessels of the brain.

[Evaluation of manganese-trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetate complex (Cyclomang) as paramagnetic contrast agent for magnetic resonance imaging].

Preclinical evaluation of a 0.5 M solution of the manganese(II)- trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetate complex (Mn-DCTA, Cyclomang) has been carried out with a view to substitution of potentially toxic gadolinium-containing paramagnetic contrast agents for clinical MRI routines. The toxicological tests of Mn(II)-DCTA were performed on mice and rats. Liquid phantoms were used for evaluating the relaxivity of Mn(II)-DCTA in comparison to that of Gd(III)-DTPA and Mn-DTPA. The diagnostic imaging properties of Mn(II)-DCTA were quantitatively assessed on dogs with cerebral meningeomas (n = 10). The LD50 upon single administration in rats was above 17 ml/kg, thus slightly exceeding the corresponding values for of Gd(III)-DTPA and Mn-DTPA. The relaxivity of Mn(II)-DCTA amounted to R1 = 3.68 (mM(-1) x s(-1)) and did not differ significantly from the values known for Gd-DTPA and Mn-DTPA. Mn(II)-DCTA ensured high-intensity contrast of tumor areas in brain of dogs. It is concluded that Mn(II)-DCTA can be employed as a paramagnetic contrast agent in routine MRI studies and is worth further clinical evaluation.

[Cells of mononuclear phagocytes system of liver and lung in rats after intravenous application of magnetite nanoparticles].

The article describes changes in the morphology and localization of the cells of mononuclear phagocyte system of liver and lung in rats at different times after single and repeated intravenous administration of a suspension of nanoparticles of magnetite (NPM). Mechanisms for removal of nanoparticles of magnetite from the rat body with the participation of mononuclear phagocytes of the liver (removal of the particles by stellate macrophages in the gastroenteric tract with bile) and of the lung (by migration of the alveolar macrophages in the gleam of the bronchial tree) have been illustrated. It has been shown that intravenous application of nanomagnetite causes changes in the morphology of the internal organs of rats and the severity of these changes increases with increasing total dose injected magnetite.

[Preclinical investigation of Mn(II)-diethylenetriaminepentaacetate (Mangapentetate) as paramagnetic contrast agent for magnetic resonance tomography].

The preclinical evaluation of 0.5 M solution of a manganese(II)-DTPA complex (Mangapentetate, Pentamang) has been carried out in order to test the ability of manganese to be used as substitute for potentially toxic gadolinium in paramagnetic contrast agents in the MRI clinical routines. The toxicologic tests of the Mn(II) - DTPA were carried out in mice, rats, and rabbits. Liquid phantoms served for direct comparison of the ability of Mn(II) - DTPA to increase the intensity of T1-weighted SE-images to the contrast properties of the Gd(III) - DTPA (Magnevist). Normal healthy rabbits (n = 12) were used for quantification of the imaging ability of Mn(II) - DTPA. The value of LD50 in rabbits was above 10 ml/kg, rather close to that one of Gd(III) - DTPA. An increase in intensity of the T1-weighted images induced by addition of Mn(II) - DTPA in phantom tests did not differ significantly from the values obtained with Gadopentetate. Mn(II) - DTPA delivered prominent enhancement of normal kidneys in healthy rabbits as well as chest tumors in dogs.

[Preclinical toxicological evaluation of Pentamang and Mangascan].

We have carried out a preclinical toxicological investigation (acute toxicity evaluation) of Mangascan (0.5 M solution of manganese(II) - EDTA complex) and Pentamang (0.5 M solution of manganese(II) - DTPA complex), a new paramagnetic contrast agents for MRI procedures. In 14 days after single intravenous introduction of Mangascan (10.0 ml/kg) or Pentamang (5.0 ml/kg) to rats, no any toxic influence of the studied agents was detected in the general condition, bone marrow, cardiovascular and central nervous systems, and liver and kidney functions of experimental animals. No pathological changes were observed in the functional activity and morphology of the internal organs and systems. The results showed that both Mangascan and Pentamang belong to the class of low toxicity substances.

[Estimation of cardiac output from dynamic contrast multispiral tomographic data].

OBJECTIVE: To describe and apply a method for programmatically calculating central hemodynamic parameters from the data of dynamic contrast X-ray computed tomography (CT). MATERIAL AND METHODS: A procedure is proposed to calculate cardiac output (CO) on the basis of the tracer dilution method as a ratio of the injected dose of a contrast agent (Urografin, Shering AG, Austria) to the area under the concentration-time curve derived for one of the cardiac chambers: [see text]. The blood concentration of the agent was estimated from the blood iodine (I) concentration-X-ray density (XD) regression dependence: [XD] = 0.49+22.07 x [I]. Thirty-three patients were studied on a multispiral X-ray Somatom Sensation 4 computed tomograph (Siemens), by injecting 15-20 ml of Urografin. The calculating method was realized as a software package for processing dynamic contrast CT data. RESULTS: The proposed method could exactly determine the values of cardiac output: the correlation with the results of the reference technique (Doppler echo measurement) was highly significant (r = 0.95; p < 0.001) in the whole range of values. Moreover, the data on XD could accurately determine the blood concentration of both iodine (I): [XD] = 0.49+22.07 x [I] and gadolinium as a component of the contrast paramagnetic Gd-DTPA for which the solution concentration-XR dependence was as follows: XD 1.2+33.6 x [Gd]. CONCLUSIONS: Thus, dynamic spiral CT may be also used for the estimation of cardiac output by the tracer dilution method.

[Arthrosonography in the diagnosis of rheumatoid arthritis of the knee joint]. / Artrosonografiia v diagnostike revmatoidnogo artrita kolennogo sustava.

The paper presents the capacities of echography in the estimation of the activity of rheumatoid gonitis. A study of knee joints in 126 patients with rheumatoid arthritis has provided the basic ultrasound criteria that are characteristic for the first, second, and third degrees of its progression, which include the pattern of proliferative changes in the synovium, the qualitative and quantitative assessments of intraarticular exudate and its viscosity. The capacities of X-ray study and MRI in the detection of the progression of rheumatoid arthritis are discussed. An algorithm of knee joint radiation study is proposed for patients with rheumatoid arthritis.

[Evaluation of endothelial permeability in brain tumors by dynamic magnetic resonance tomography with magnevist contrast imaging on low-field MR-tomograph]. / Otsenka endotelial'noi pronitsaemosti opukholei mozga metodom dinamicheskoi magnitno-rezonansnoi tomografii s kontrastirovaniem Magnevistom na nizkopol'nom MR-tomografe..

In order to study the endothelial permeability to hydrophilic macromolecules in brain tumors we have developed a technique based on Gjedde-Rutland-Patlak approach to dynamic MRI study with Gd-DTPA injected intravenously, performed with low-field MRI tomograph Magnetom Open (Siemens medical). 27 patients with various brain tumors were referred for the study. The indices of Gd-DTPA transport to tumor tissue (KGd-DTPA) vary substantially, depending on the degree of malignancy and deliver essential information on microvascular permeability of tumor capillary bed.

[Quantification of volume of tissue damage in stroke using T2- weighed MRI images]. / Kolichestvennaia otsenka ob"ema ishemicheskogo povrezhdeniia golovnogo mozga po dannym analiza T2-vzveshennykh MRT-izobrazhenii.

We have developed a quantitative technique for scoring of the severity of ischemic damage of the brain using quantitative data of the T2-weighted MRI images of brain in stroke. The principle of the method is the assumption that T2 signal increases proportionally to the severity of ischemic damage of cerebral tissue up to the level equal to intraventricular liquor signal in the case of postinfarction cystic degeneration. Depicting the mean T2-signal from the intraventricular liquor region as Iliq, the signal from ischemic brain area as Iinsult, and from the intact brain as Inorm, obviously, the volume quota of damaged tissue in the total volume of the stroke region is represented by the ratio (Iinsult - Inorm)/(Iliq - Inorm). The total volume of damaged tissue (VDT, cub.cm) in the stroke region is then the following sum taken over all slices i, where the stroke damage can be: VDT = sigma i d.Si.[(Iinsult - Inorm)/(Iliq - Inorm)]i, where d is the slice thickness, Si--area of the ischemic region in the slice i. The quota of damaged tissue in the physical volume of the stroke region is henceforth the following ratio: Q = [sigma i d.Si.[(Iinsult - Inorm)/(Iliq - Inorm)]i]/[sigma i d.Si]. The technique was applied in retrospective analysis of routine MRI studies in 15 patients referred because of acute ischemic stroke. The studies were performed using low-field MRI tomograph Magnetom-Open (Siemens Medical) with field strength 0.22 T. In patients studied during the first day after occurrence of ischemic insult with the minimal degree of acute neurologic deficit, who later have demonstrated clinically full recovery, the VDT was below 20 cm3, and Q was below 10%. In cases with VDT > 25 cm3 and Q > 20% the full regress was not observed in any patient. Henceforth, the quantification of cerebral damage in stroke using quantitative indices based on measurement of T2-parameters over ischemic and intact zones of the brain are of independent prognostic clinical value and improve clinical usefulness of the MRI in ischemic brain stroke.

[Radiologic diagnosis of bone metastases recurrence in patients with prostate cancer treated strontium-89]. / Luchevaia otsenka regressa kostnykh metastazov u patsientov s rakom prostaty pri sistemnoi radioterapii 89SrCl.

Aiming to evaluate efficiency of 89SrCl (Metastron) in patients with metastatic lesion of the skeleton in prostate cancer we have performed a follow-up scintigraphy of the skeleton with 99mTc-methylendiphosphonate (MDP) and MRI with quantitative study of metastatic foci. 12 patients with prostate cancer (on the average 11 +/- 6 bone metastases were examined using scintigraphy of the skeleton with 99mTc-MDP and MRI study in T1, T2 and proton density modes. Investigations were performed before injected as a single dose of 150 MBq (4 mCi). At all the stages there was made a quantitative study of foci of pathological uptake of 99mTc-MDP compromising numbers of foci, focus parameters, intensity of 99mTc-MDP accumulation in the pathological part relatively the contralateral region as well as quantification of MRI signals from metastatic areas in signal intensity units. In 3 month 4 patients with extensive metastatic skeletal lesion (> 12) showed a considerable decrease of number of foci of pathological 99mTc-MDP uptake (on average to 6 +/- 3). In the remained metastatic foci there was noted a decrease of dimensions and 99mTc-MDP uptake intensity at an average by 29.8 +/- 15%, improvement in T1 intensity by 113 +/- 55.6 units. In 2 patients who initially presented a "superscan" pattern on 99mTc-MDP bone scintigraphy the 89SrCl treatment converted this of low intensity had demonstrated their complete regression. Results of radiologic follow-up of bone metastases in prostate cancer using MRI and bone scintigraphy with 99mTc-MDP argue that systemic radiotherapy with 89SrCl induces significant regress of metastatic process that involves all volume of the metastases.

[The use of a new method for determining the ratio of the glomerular filtration rate to circulating plasma volume in patients with arterial hypertension]. / Primenenie novogo metoda opredeleniia otnosheniia skorosti klubochkovoi fil'tratsii k ob''emu tsirkuliruiushchei plazmy u bol'nykh arterial'noi gipertoniei.

Renal scintigrams with 99Tc-DTPA were analysed retrospectively in 19 patients with essential hypertension. Glomerular filtration rate (GFR) was measured by Gates technique. Ratio GFR to plasma volume (PV) was quantified by A. M. Peters' technique (1994). PV was calculated as the relation of these two indices. Total GFR in hypertensive patients widely ranged (from 76.8 ml/min to 165.7 ml/min). Three groups were selected taking into account hypertension duration: patients with decreased, normal and increased values of basal GFR. The severity of hypertension did not affect the GFR, but showed positive and strong correlation with PV (r = 0.91; p < 0.05). GFR/PV was decreased in hypertensive patients. Factors affecting the GFR in hypertensive subjects are discussed.

[Assessing the effect of prosthesis of the brachiocephalic trunk]. / Otsenka éffekta protezirovaniia brakhitsefal'nogo stvola.

The early and long-term results of truncus brachiocephalicus prosthetics in its atherosclerotic occlusions are analysed. EEG mapping, radioisotopic examination of cerebral circulation before and after surgery, clinical examination were performed for evaluation of effectiveness and safety of surgery. The rate of mortality was 6.6%. The technical recommendations are provided. All the patients, who were discharged after surgery, are alive for 2.6 +/- 0.3 years. No cases of recurrence of cerebral circulation disorders were observed. In 100% cases the grafts were patent.

[The cerebral hemodynamics of patients with ischemic heart disease during transesophageal electrical stimulation of the left atrium]. / Sostoianie tserebral'noi gemodinamiki u bol'nykh ishemicheskoi bolezn'iu serdtsa vo vremia chrespishchevodnoi élektricheskoi stimuliatsii levogo predserdiia.

In 26 patients with coronary heart disease, transesophageal atrial pacing was used to study cerebral hemodynamics from brain tomoscintigraphic findings as compared to the severity of induced of myocardial ischemia, echocardiographic parameters of left ventricular function and prostacyclin-thromboxane balance. In angina pectoris, the lower rate of cerebral blood flow was found to be correlated with the integral parameter of myocardial ischemia, deteriorated cardiac contractile and pump function, and higher plasma thromboxane A2 levels.

[The importance of the noninvasive scintigraphic assessment of pulmonary arterial pressure in persons who have had an acute myocardial infarct]. / Znachenie neinvazivnoi stsintigraficheskoi otsenki legochnogo arterial'nogo davleniia u lits, perenesshikh ostryi infarkt miokarda.

Twenty-two patients with a history of acute myocardial infarction underwent pulmonary perfusion scintigraphy at rest and during bicycle exercise testing. 99mTc-labelled human albumin microspheres were used. The perfusion ratio in the upper and lower pulmonary regions (U/L ratio) was calculated from scintigraphic findings. There was a close correlation between mean pulmonary blood pressure and U/L ratio (r = 0.95). It was established that the absence of microcirculatory bed reserve scintigraphically revealed in the lesser circulation in patients with prior myocardial infarction may be considered to be a negative predicator.

[Cerebral blood flow after carotid-subclavian shunting]. / Mozgovyi krovotok u bol'nykh posle operatsii sonno-podkliuchichnogo shuntirovaniia.

The radioisotope and rheography methods were used to study the cerebral blood flow in 12 patients in the late-term periods after formation of a carotid-subclavian shunt in occlusion of the initial segments of subclavian arteries. It is shown that an intact donor common carotid artery ensures adequate supply of blood to the brain and upper extremity.

[Regional lung perfusion in patients with chronic nonspecific lung diseases based on scintigraphic study data]. / Regionarnaia perfuziia legkikh u bol'nykh khronicheskimi nespetsificheskimi zabolevaniiami legkikh po dannym stsintigraficheskikh issledovanii.

Perfusion scintigraphy of the lungs with 99mTc-labeled microspheres was used for a study of changes of regional perfusion of lesser circulation in patients with chronic bronchitis of a varying degree of disturbed pulmonary hemodynamics. Even before a stable rise of pulmonary vascular resistance and development of pulmonary arterial hypertension, chronic bronchitis was characterized by redistribution of the blood flow from the lower parts of the lungs to the upper ones, which progressed with disturbance of pulmonary arterial circulation and the development of chronic cor pulmonale. This redistribution could be determined by an earlier and more important rise of the vascular tone and resistance to the blood flow in the lower parts of the lungs. The use of scintigraphic indices of the upper and lower parts (U/L) perfusion ratio led to adequate assessment of a degree of redistribution of the pulmonary blood flow in patients with chronic bronchitis.

[The microcirculatory reorganization of the lesser circulation during the rehabilitation of myocardial infarct patients]. / Perestroika mikrotsirkuliatsii malogo kruga v protsesse reabilitatsii bol'nykh infarktom miokarda.

A study was made of the regional distribution of the pulmonary blood flow by means of perfusion scintigraphy of the lungs with 99mTc-albumin macroaggregates with relation to a clinical course of CHD, the state of intracardiac and pulmonary hemodynamics. The time course of microcirculation in the lesser blood flow during rehabilitation of patients after myocardial infarction was assessed. Redistribution of the pulmonary blood flow was shown to be connected with the clinical features of a course of CHD, severity of myocardial lesion, and a degree of disorder of intracardiac and pulmonary hemodynamics. Therefore these changes can be of important prognostic value in patients after myocardial infarction.