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Biomedical subjects

V E Sinitsyn

Publications and source records attributed to V E Sinitsyn.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[3D FSPGR (fast spoiled gradient echo) magnetic resonance imaging in the diagnosis of focal cortical dysplasia in children].

Small dysplastic lesions of the cerebral cortex are often missed by conventional MRI methods. The identification of subtle structural abnormalities by traditional multiplanar rectilinear slices is often limited by the complex convolutional pattern of the brain. We used a method of FSPGR (fast spoiled gradient-echo) of three-dimensional MRI data that improves the anatomical display of the sulcal structure of the hemispheric convexities. It also reduces the asymmetric sampling of gray-white matter that may lead to false-positive results. We present 5 from 12 patients with dysplastic cortical lesions in whom conventional two-dimensional and three-dimensional MRI with multiplanar reformatting was initially considered normal. Subsequent studies using 3D FSPGR identified various types of focal cortical dysplasia in all. These results indicate that an increase in the detection of subtle focal dysplastic lesions may be accomplished when one improves the anatomical display of the brain sulcal structure by performing 3D FSPGR.

Adolescent↗
PubMedDate not supplied

[Magnetic resonance urography: possibilities and prospects].

A new technique of urinary tracts visualization--magnetoresonance urography (MRU)--for a year (2000) was applied in examination of 25 patients aged 17 to 63 years with ureteral concrements (n = 11), ureteropelvic stenosis (n = 10), ureteral stenosis (n = 2), urinary bladder tumor (n = 1), Ormond's disease (n = 1). MRU provides the same information about the obstruction and dilatation of the urinary tracts as excretory urography (EU). In cases of EU contraindication (allergy, renal failure) or lack of contrast substance excretion, MRU allows to avoid additional invasive diagnostic procedures. It also enables visualization of non-dilated urinary tracts in medicinal polyuria. Non-invasiveness, no need to contrast, absence of radiation load open wide perspectives for MRU application in various groups of patients including pregnant women.

Adolescent↗
PubMedDate not supplied

[Dynamic magnetic resonance prostatovesiculography in diagnosing prostatic cancer].

Dynamic MR prostatovesiculography (DMRP) is a new method of prostatic cancer diagnosis based on the ability of cancer tissue to accumulate contrast substance (omniscan) than benign tissue. Urologists from the I.M. Sechenov Moscow Medical Academy have examined 23 patients (5 patients with prostatic cancer and 18 suspects) who have undergone standard investigations (test for PSA, finger rectal examination, transrectal ultrasound investigation) and DMRP. DMRP detected prostatic areas suspected of malignancy. Taking biopsy from such areas verified diagnosis of prostatic cancer in 2 patients.

Aged↗
PubMedDate not supplied

[Comparative assessment of resting myocardial perfusion in patients with postinfarct cardiosclerosis by electron-beam tomography and 99mTc-MIBI myocardial single-photon tomography].

The purpose of the study was to compare myocardial perfusion assessed by electron beam computed tomography (EBCT) with that obtained by 99mTc-sestamibi single photon emission computed tomography (SPECT) in patients with old myocardial infarction and control subjects at rest. A total of 42 patients with suspected and known ischaemic heart disease (IHD) were included in the study. 20 pts had a history of Q-wave myocardial infarction (MI), 12 pts had an old non-Q-wave MI and 10 served as controls (without perfusion defects on SPECT images at rest). Assessment of the myocardial perfusion by EBCT was performed using the short axis view and multislice mode (MSM) during injection of 50 ml of the nonionic contrast medium at 4 ml/s via cubital vein. Perfusion defects were localized by SPECT according to 6-segment model of the LV (septal, anterior, lateral, posterior, inferior and apical). Overall concordance between EBCT and SPECT was 67% for normal versus abnormal perfusion. Agreement between the 2 methods for each of the 6 segments was 81% (K = 0.62) for the anterior segment, 71% (K = 0.42) for the septal segment, 71% (K = 0.43) for the apical, 69% (K = 0.3) for the lateral segment, 48% (K = 0.13) for the posterior segment and 60% (K = -0.13) for the inferior segment. Discrepancies between the two of techniques were most notable in the posterior region. Beam hardening during passage of the contrast medium through the heart chambers and descending aorta is possible explanation of the artifacts on EBCT images. This study demonstrates that nowadays EBCT is not yet alternative to SPECT in the assessment of the myocardial perfusion in patients and further improvements of scanning techniques are necessary.

Blood Flow Velocity↗
PubMedDate not supplied

[Quantification of volume of tissue damage in stroke using T2- weighed MRI images].

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.

Brain↗
PubMedDate not supplied

[Patterns of cerebral blood flow reactivity in adenosine stress-test in patients with carotid stenosis evaluated with MRI and emission tomography with 99m Tc-HMPAO].

In this study we evaluated the adenosine stress-test combined with 99mTc-HMPAO SPECT as a possible tool for evaluation of brain perfusion reserve in patients with various degrees of cortical neurologic damage due to internal carotid artery stenosis. The investigation comprised 37 patients with atherosclerotic carotid disease, in everybody of whom the stenosis was detected by echo-Doppler study of carotids and later in 28 verified also using invasive intraarterial digital subtractive angiography. In everybody the 99mTc-HMPAO SPECT study was performed twice: at rest and during stress-test with intravenous injection of adenosine with the patient in the supine position. It was gathered three groups of patients with different kinds of cerebral blood flow reactivity in adenosine stress-test. Henceforth, we conclude that, first, the 99mTc-HMPAO SPECT adenosin stress challenge of cerebral blood flow is a reliable functional test for every group of patients with extensive atherosclerosis and can be used for detection of patients with exhausted or decreased cerebral perfusion reserve in whom the risk of future cerebral vascular ischaemic events is elevated.

Adenosine↗
PubMedDate not supplied

[Magnetic resonance tomography in the diagnosis of aneurysm and coarctation of the thoracic aorta].

MR-tomography (MRT) was performed in 25 patients with aneurysms and in 11 with coarctation of the thoracic aorta. For investigations a device with a resistive magnet (the force of a field--0.23 T) was used simultaneously with ECG. MRT revealed all cases of aortic dissection (10 patients) and one case with a false-positive result. Oblique sections in the direction of the thoracic aorta were used to assess the state of the aortic arch branches. Comparison of MRT and x-ray computerized tomography has shown that the diagnostic value of both methods was almost equal, however MRT was a safer method and easier to use. MRT was shown to be a method of choice for diagnosis of aneurysms and coarctations of the thoracic aorta but cannot be a substitution for aortography.

Adolescent↗
PubMedDate not supplied

[Magnetic resonance tomography in the diagnosis of aneurysms and coarctations of the thoracic aorta].

MR-tomography (MRT) was performed in 25 patients with aneurysms and in 11 with coarctation of the thoracic aorta. For investigations a device with a resistive magnet (the force of a field--0.23 T) was used simultaneously with ECG. MRT revealed all cases of aortic dissection (10 patients) and one case with a false-positive result. Oblique sections in the direction of the thoracic aorta were used to assess the state of the aortic arch branches. Comparison of MRT and x-ray computerized tomography has shown that the diagnostic value of both methods was almost equal, however MRT was a safer method and easier to use. MRT was shown to be a method of choice for diagnosis of aneurysms and coarctations of the thoracic aorta but cannot be a substitution for aortography.

Adolescent↗
PubMedDate not supplied

[Magnetic resonance tomography, computed tomography and ultrasonic diagnosis of hemangiomas of the liver].

The paper is concerned with the potentialities of modern radiation methods in the diagnosis of liver hemangiomas. USI, CT, angiography and MR-tomography (MRT) were used for investigation of 64 patients with liver hemangiomas. The diagnostic potentialities and the role of each of the above methods in the diagnostic algorithm in liver hemangiomas were studied. The results of the investigation have shown that MRT possesses a higher informative value than USI and CT in the diagnosis of liver hemangiomas and can even replace angiography in the verification of diagnosis.

Adult↗
PubMedDate not supplied

[Determination of the ejection fraction and cardiac volumes using magnetic resonance tomography].

The results of NMR-tomography and radiocontrast ventriculography (VG) were compared in 20 CHD patients to determine ejection fraction (EF), and left ventricular (LV) end-diastolic and end-systolic volumes (EDV and ESV). NMR-tomography of the heart was performed at the field power of 0.23 T using the synchronization with ECG. Two methods of orientation of NMP-section on the LV long axis were employed. A sufficiently high correlation of NMR-tomography and VG findings in the determination of EF (r = 0.9) was obtained, low and insignificant--in the determination of EDV and ESV. Possible causes of differences between the results of both methods are under discussion.

Adult↗
PubMedDate not supplied

[Use of Omniscan (gadodiamide) in magnetic resonance studies of the central nervous system (results of a multicenter study)].

The aim the study: was to conduct first in Russia multicenter trial of gadodiamide in brain and spine MRI in adult patients. Open noncomparative multicenter (5 clinical centres) study. Brain and spine MRI was performed in 190 adult patients with signs of CNS disorders. Field strength of MR imagers was 0.04-1.5 T. Gadodiamide ("Omniscan", "Nycomed Imaging", Nycomed) was injected IV in dose 0.1 mmol/ml. Contrast enhancement was obtained in 74% cases. Gadodiamide allowed to detect more new lesions, better differentiate borders and internal structure of lesions, to differentiate them from oedema and surrounding structures. Contrast-enhanced MR images were superior to non-enhanced T1 and T2-weighted images and to CT images (before and after contrast enhancement). Use of gadodiamide increased confidence in diagnoses in 90.4% cases, changed the diagnosis in 30.3% cases. The general number of adverse events was 2.6%. Adverse reactions to gadodiamide were seen in 1.6%; all of them were of mild intensity without need for therapy. Gadodiamide is an effective and safe nonionic paramagnetic contrast media for brain and spine MRI in adult patients.

Adolescent↗