Contrast Agents Based on Iron Oxide Nanoparticles for Clinical Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) is one of the most perspective methods of noninvasive visualization in medicine, and use of contrast agents significantly its potentialities extends. Iron oxide nanoparticles are promising contrast agents, but in fact all the data on their efficiency were obtained in high-field tomographs for experimental animals. We studied the possibility of using magnetic nanoparticles for MRI visualization of rat brain glioblastoma at the most common clinical field 1.5 T The data indicate the efficiency of iron oxide magnetic nanoparticles as contrast agents for 1.5 T MR tomographs.

[Magnetic resonance imaging in the diagnosis of recurrent prostate cancer].

The article reviews the domestic and international literature on local recurrence of prostate cancer both after surgery and non-invasive treatments. The authors describe modern high-precision techniques used in magnetic resonance imaging that are used today in clinical practice for the most accurate detection of recurrent prostate cancer lesions.

[State of the art of the problem concerning endovascular treatment of abdominal aortic aneurysms of infrarenal localization]. / Sovremennoe sostoianie problemy éndovaskuliarnogo lecheniia anevrizm briushnoi aorty infrarenal'noi lokalizatsii.

The problem concerning diagnosis and treatment of abdominal aortic aneurysms (AAA) is important today because of a high proportion of this pathology within the structure of population morbidity and mortality, with a tendency of these indices to increase, as well as high lethality rates in development of complications. Endovascular treatment of aortic aneurysms is one of the most rapidly developing methods of treatment in vascular surgery. Over the last two decades this type of treatment has been playing an important part in the armamentarium of the vascular surgeon and is often considered as primary treatment of patients with AAA of infrarenal localization. Nevertheless, long-term efficacy and reliability of this method have been argued. These argues are based on the fact that according to the findings of various studies the advantages of endovascular treatment of aneurysms over open surgical treatment are completely leveled after 6-8 years. The main disadvantage of endovascular treatment is the necessity of repeat interventions in the long-term period of follow-up. However, in a series of studies repeat interventions in groups of both surgical and endovascular treatment were either not taken into account or not specially studied. It should also be taken into consideration that first European studies were carried out with the use of grafts of first generations, and some of them are not used any more. Therefore, the necessity of carrying out further studies still remains. Perhaps, new generations will be able to decrease the frequency of repeat interventions and thereby improve the overall results of endovascular treatment. The possibilities of endovascular treatment of AAAs will constantly be extended, including due to the development of X-ray equipment and software, as well as at the expense of various auxiliary technologies.

[Atrial fibrillation as consequence and cause of structural changes of atria].

Changes of atrial structure and function are the contributors of atrial fibrillation clinical course, complications and treatment effectiveness. Effects of inflammation and mechanical stretch on atrial structural remodeling leading to atrial fibrillation are reviewed in the article. Contemporary invasive and non-invasive methods of evaluation (including late gadolinium enhancement magnetic resonance imaging) of patients with atrial structural remodeling in atrial fibrillation are also described.

[The role of multispiral computed tomography in assessment of viability of the myocardium and prognostication of left ventricular remodeling in patients with ST-elevation myocardial infarction].

Aim of the study was to assess perfusion defect and viability of the myocardium by the method of multispiral computed tomography (MSCT) in patients with ST-elevation acute myocardial infarction (AMI) and to assess their prognostic role in development of remodeling of the left ventricle (LV). We included into the study 117 patients with AMI. MSCT with intravenous contrast enhancement was carried out on days 3-4 and at 12 months after AMI. In the arterial phase we estimated volume of myocardial perfusion defect, LV end diastolic and end systolic volumes (LVEDV and LVESV), and LV ejection fraction (EF). Three types of myocardial opacification were distinguished on tomograms in delayed phase of MSCT: type I - subendocardial residual defect (RD), type II - transmural RD, type III - transmural delayed hyper enhancement (DE). Patients were divided in 3 groups: (1) with subendocardial RD (n=63), (2) with transmural RD (n=28), (3) with transmural DE (n=26). Development of LV remodeling was registered if at repeat MSCT LVEDV increased more or equal 20% from baseline. In patients with signs of viable myocardium (group 1) volume of perfusion defect was substantially smaller than in patients with nonviable myocardium (groups 2 and 3): 1cm3 (0.4-2.4) vs. 7.3 cm3 (5.3-10.0) and 6.3 cm3 (5.0-15.0), respectively, p<0.001. Compared with groups 2 and 3 patients of group 1 more often were female (p=0.04), had inferior MI (p<0.001), and spontaneous reperfusion (p<0.001). After 12 months LV remodeling was registered in 19.3% of patients, all had signs of nonviable myocardium in more or equal 3 LV segments. In patients with perfusion defect more or equal 10 cm3 probability of development of LV remodeling exceeded 50%. Disturbances of perfusion abnormalities and number of nonviable LV segments were main predictors of LV remodeling.

[Comparison of characteristics of atherosclerotic plaques in patients with acute coronary syndrome and stable ischemic heart disease: data of multispiral computed tomography].

AIM: To elucidate possibilities of multispiral computed tomography (MSCT) for assessment of morphology of atherosclerotic plaques in coronary arteries of patients with acute coronary syndrome (ACS) or stable ischemic heart disease (SIHD). MATERIAL AND METHODS: Assessment of internal relief of coronary arteries and composition of atherosclerotic plaques was carried out in 85 patients with ACS and 41 patients with SIHD. MSCT was performed with the use of computed tomograph. Visual assessment included determination of plaque type (calcified, soft, and heterogeneous) and contour (regular, irregular). Quantitative assessment included determination of plaque density and index of remodeling. RESULTS: Among patients with ACS we found 194 plaques (60--soft, 72--heterogeneous, and 62--calcified). Plaques in symptom related compared with non-symptom related arteries had higher index of remodeling (1.4 +/- 0.3 and 1.2 +/- 0.2, respectively, p < 0.0001), and more frequently had irregular contour (60.0 and 12.8%, respectively, p < 0.0005). Soft plaques and plaques with irregular contour prevailed in ACS group (68.0%) while calcified plaques were more frequent in SIHD group (66.4%). Plaques with irregular contour were more frequent and index of remodeling was higher in ACS compared with SIHD group (33.5 vs 7.2%, p < 0.0005, and 1.3 +/- 0.2 vs 1.0 +/- 0.2, p < 0.001, respectively). CONCLUSION: According to MSCT data main characteristics of atherosclerotic plaques in patients with ACS were low density and inclusions of microcalcinates. Specific features of plaques in symptom related arteries were irregular contour and positive remodeling index.

[Informative value of multislice spiral computed tomography in identifying myocardial perfusion defect in patients with acute myocardial infarction].

AIM: To estimate the informative value of multislice spiral computed tomography (MSCT) in the diagnosis of myocardial infarction (MI). SUBJECTS AND METHODS: The study enrolled 171 patients with acute coronary syndrome (ACS), including 121 patients diagnosed with acute ST-segment elevation MI (STEMI), 19 with non-STEMI, and 31 with unstable angina. A comparison group consisted of 52 patients with stable coronary heart disease (CHD) and a control group comprised 17 patients without CHD. Intravenous contrast-enhanced MSCT was performed using a 64-spiral CT scanner. MSCT was carried out in the patients with ACS on days 3-5 of the onset of a pain attack and in the other patients electively. It was redone in 44 patients with acute MI (AMI) 6 months after a primary examination. RESULTS: Left ventricular (LV) perfusion defect was imaged in 94.3% of the patients with AMI and in 10% of those with unstable angina. LV contrast defects were undetectable in the patients from the stable CHD and control groups. The sensitivity, specificity, prognostic value of a positive result, negative prognostic value of a result, and accuracy of MSCT in the diagnosis of MI were 94.3, 97.1, 97.8, 92.5, and 96.70%, respectively. In the patients with STEMI, myocardial perfusion defect was larger and transmural perfusion defect was more common than in those with non-STEMI. Comparison of the values of myocardial perfusion defect size and myocardial density according to the data of primary and repeat MSCT revealed no statistically significant differences: 2.0 (0.50; 5.45) and 1,8 (0.35; 5.00) cm3 (p = 0.15); 41.7 +/- 10.2 and 46.1 +/- 12.2 HU, respectively (p = 0.07). CONCLUSION: Contrast-enhanced MSCT allows visual and quantitative assessments of myocardial perfusion defect in patients with ACS. Myocardial perfusion defect from MSCT data suggests previous MI with a high probability, but does not permit the determination of the duration of the disease.

[Comprehensive magnetic resonance imaging for breast cancer].

AIM: To enhance the efficiency of diagnosis of breast tumors by comprehensive magnetic resonance imaging (MRI) involving dynamic contrast-enhanced magnetic resonance mammography (MRM) and magnetic resonance spectroscopy (MRS). SUBJECTS AND METHODS: Eighty-seven women aged 32 to 75 years with breast neoplasms were examined. MRM was performed on a Philips Achieva 3.0T TX scanner. The MRI protocol consisted of axial fat-suppressed T1- and T2-weighted spin-echo images and 8 postcontrast dynamic series. Changes in contrast-enhanced MRI of breast cancer (BC) were estimated by constructing the signal intensity-time curves. MRS was carried out using a PRESS sequence. RESULTS: Dynamic MRM determined type III signal intensity-time curve in 83.9% of the patients with BC and type II curve in 16.1% of those with breast malignancies and in 33.3% of those with breast fibroadenomas. Type I signal intensity-time curve was identified in 66.7% of the cases of fibroadenomas. Elevated choline concentrations in the malignancies were detected in 17.7% of cases. Their tumors were larger than 2 cm. The choline peak in the malignancies could not be revealed in the other cases, which was associated to the large voxel size exceeding the mass size. There was a drastic fall in the signal-to-noise ratio with smaller voxel sizes. Furthermore, higher choline levels were determined in 9.5% of the fibroadenoma cases. Comparison of MRS findings before and after contrast injection revealed the advantage of the latter, which is primarily attributed to the more accurate voxel position on the tumor than that during non-contrast-enhanced MRS. CONCLUSION: Dynamic intravenous contrast-enhanced MRM is an effective method for the differential diagnosis of breast masses. MRS cannot be included in the standard study protocol for women with breast masses for the present.

[Myocardium non-compaction].

The left ventricular non-compaction (spongy cardiomyopathy) is a rare, poorly known pathology. Disease according to WHO classification applies to unclassified cardiomyopathy. Clinical picture is nonspecific. Diagnosis is established by means of instrumental techniques such as echocardiography and magnetic resonance imaging. Spongy cardiomyopathy usually affects the left ventricle, right ventricular failure occurs much less frequently. We present a description of the disease in 18 years old girl with signs of myocardial infarction and non-compaction of both (left and right) ventricles.

[31P magnetic-resonance spectroscopy in cardiac diseases].

Magnetic Resonant spectroscopy (MRS) in the nuclei of phosphorus is the only noninvasive method of studying the state of myocardial energy metabolism does not require the introduction of radiopharmaceuticals. This method uses the signals from the nuclei of 31P contained in such mattered phosphates like phosphocreatine and adenosine triphosphate. MRS can provide an answer to a variety of theoretical and clinical issues in the study of various cardiac diseases. The first is ischemic heart disease, as well as heart failure, hypertrophy of various origins, etc. In addition, the method can be used to control the various treatments, including therapeutic, interventional or surgical. Combined with magnetic resonance imaging of the heart gives information on the anatomy, size, function, perfusion defects, structural changes of the myocardium, as well as about the state of energy metabolism of myocardium.

[The potential of multislice computed tomography for the detection of specific anatomic and topographic features of the facial nerve canal prior to stapedoplasty].

The objective of the present study was to estimate the potential of multislice computed tomography (MSCT) for the detection of specific anatomic and topographic features in the structure of the middle ear and the oval window region prior to stapedoplasty. We analysed the results of MSCT of the temporal bones in 20 patients presenting with otosclerosis (40 observations). All these patients underwent stapedoplasty, and the intraoperative findings were compared with the MSCT data. Specificity and sensitivity of MSCT for the detection of structural abnormalities in the middle ear were estimated at 91.3% and 84.6% respectively. It is concluded that the preoperative MSCT examination of the temporal bones yields the data that allow for the more accurate planning of the succeeding surgical intervention as well as for choosing its optimal strategy and extent, proper instruments, the type and length of the implant (prosthesis), and thereby for avoiding the possible complications and improving the prognosis of the treatment.

[Functional multispiral computed tomography of sound-transmitting structures in the middle ear].

The objective of this work was to estimate the potential of functional multispiral computed tomography (fMSCT) for the choice and planning of the treatment strategy and the extent of surgical intervention in the patients presenting with fibroosseous diseases of the middle ear associated with the pathologically altered mobility of the auditory ossicles. Studies with the use of MSCT and fMSCT for the examination of temporal bones in 21 patients (25 observations) provided information about normal CT anatomy of the middle ear and a basis for the development of the fMSCT protocol; moreover they allowed the range of mobility of the auditory ossicles to be determined in healthy subjects and patients with middle ear disorders. It is concluded that fMSCT of temporal bones may be recommended to patients suffering otosclerosis, tympanosclerosis, and adhesive otitis media. The use of this technique improves the accuracy of diagnosis and facilitates the choice and planning of the treatment strategy and the extent of surgical intervention in the patients presenting with middle ear diseases.

[Lesions in lungs in patients with rheumatoid arthritis].

The aim of this work was to study the prevalence and clinical features of affection of lungs and lower respiratory tract (LRT) in patients with rheumatoid arthritis (RA). A total of 104 non-smoking patients with RA and 100 ones without RA or chronic pulmonary diseases were examined. RA was associated with affection of all parts of the respiratory tract including proximal and distal bronchi, lung interstitium, and pleura. Bronchopulmonary disorders in RA patients had multilevel character suggesting continuous inflammation and sclerotization of anatomic respiratory structures. Lesions in lungs and LRT are shown to be of prognostic value (bronchiectasis, bronchiolitis, interstitial pneumonia), they frequently produce only weak clinical symptoms, and therefore need to be actively detected. Combination of functional tests and imaging techniques is of primary importance for diagnosis of respiratory problems in patients with RA.

[Diagnostic value of CT angiography in coronary arteries stenosis detection].

BACKGROUND: Noninvasive imaging of coronary arteries is very important. CT angiography (multislice computed tomography and electron beam computed tomography -- MSCT and EBT) is most reliable method for noninvasive coronary visualization. PURPOSE: The aim of our study was to evaluate the diagnostic value of CT angiography in coronary arteries stenoses detection in patients with coronary arteries disease (CAD). MATERIALS AND METHODS: 140 patients with CAD who underwent EBT (n=97) or 4-slice CT (n=43) coronary angiography and conventional coronary angiography as a gold standard were included in the study. RESULTS: Sensitivity and specificity of CT angiography in coronary stenoses detection (proximal and mid segments) were 86% and 97%, respectively. Positive and negative predictive values were 90% and 96%, respectively. Overall accuracy was 95%. 6.2% of coronary segments were excluded from the study because of unsatisfactory image quality. CONCLUSIONS: CT angiography is noninvasive method for coronary stenoses detection with high sensitivity and specificity. Nevertheless EBT and 4-slice CT angiography can not replace conventional coronary angiography because of lower temporal and spatial resolution, artifacts in patients with arrhythmias and huge coronary calcification.

[The role of multidetector computed tomography in detection of myocardial infarction].

UNLABELLED: The aim of the study was to assess the diagnostic value of multidetector computed tomography (MDCT) in detection of myocardial infarction (MI) in acute and chromic stages. MATERIAL AND METHODS: 49 patients with suspected MI were included in the study. In 44 patients the diagnosis of acute MI had been confirmed according to standard criteria. Contrast-enhanced MDCT of the heart and vessels was performed with 4-row MDCT scanner. RESULTS: MDCT detected areas of MI in 39 of 44 patients with proven MI. In 66,7% of cases they were transmural and in 33,3% -- subendocardial. In arterial phase the density of infarcted area was significantly lower than in normal myocardium (mean, 32,6 +/- 3,7 HU versus 101,9 +/- 3,7 HU, correspondingly, p < 0,0001). Mean values of myocardial density in the area of the MI did not change during follow-up (32,6 +/- 3,7 HU vs 41,3 +/- 4,5 HU, ns). In comparison to SPECT, sensitivity and specificity of MDCT in detection of transmural MI were 96,9% and 100%. corr. In the whole group of patients, taking results of troponin test as a gold standard, the sensitivity of MDCT in detection of Q-MI and non-Q MI were 89,1% and 93,5%, correspondingly. CONCLUSION: Cardiac MDCT can reliably detect and localize areas of acute and chronic MI. Contrary to SPECT, it also gives information about stenosis and occlusions in the coronary arteries.

[Comparison of non-invasive electron-beam and multislice CT angiography efficacy for detection of coronary artery stenosis].

AIM: To compare diagnostic value of electron-beam CT (EBT) and multislice CT (MSCT) angiography in detection of coronary artery stenosis in patients with coronary artery disease (CAD). MATERIAL AND METHODS: 140 CAD patients who had undergone EBT (n = 97) or 4-slice CT (n = 43) coronary angiography and conventional coronary angiography as a gold standard were included in the study. RESULTS: Sensitivity and specificity of EBT angiography in coronary stenosis detection (proximal and mid segments) were 86 and 97%, respectively. Sensitivity and specificity of MSCT angiography were 87 and 98%, respectively. 6 and 7% of coronary segments were excluded from the study because of bad image quality in EBT and MSCT groups, respectively. CONCLUSION: No significant difference was registered in diagnostic value of EBT and 4-slice MSCT angiography in coronary artery stenosis detection.

Aneurysm of aortocoronary bypass graft: two clinical case reports.

The article deals with the description of two clinical case reports of a rare complication following operations of aortocoronary bypass grafting, i. e., aneurysms of aortocoronary bypass grafts. The diagnosis of an aneurysm of the bypass graft was in both cases made by means of modern methods of radiodiagnosis, namely, electron-beam tomography and multislice helical computed tomography.

[Safety of magnetic resonance imaging after coronary stenting].

Magnetic resonance imaging (MRI) is contraindicated to some patients with certain types of metallic devices and implants (e.g. cerebral surgical clips, defibrillators). There are some controversies concerning safety of MRI in patients with metallic coronary stents in cases when MRI examination is performed earlier then one month after stent implantation. Analysis of published data has shown that MRI performed with systems having field strength up to 3 Tesla does not cause migration and heating of both bare and coated stent and is not associated with increased risk of coronary artery thrombosis. MRI can be performed safely in first days after coronary stent implantation. Small local artifacts on MRI images do not influence interpretation of the data (except for cases of coronary magnetic resonance angiography).

[Quantitative analysis of coronary artery calcinosis: comparative informative value of multispiral computed tomography and electron-beam tomography].

AIM: To compare informative value (IV) of electron-beam tomography (EBT) and multispiral computed tomography (MSCT) in the assay of coronary artery calcinosis with participation of one group of patients. MATERIAL AND METHODS: EBT and MSCT were conducted in 210 patients whose mean age was 60.6+/-7.7years (67% males, mean age 60.2+/-7.6 years; 33% females, mean age 61.5+/-8.3 years) with a verified diagnosis of ischemic heart disease (IHD). RESULTS: 185 patients had calcium index (CI) from 21 to 2636 units. EBT and MSCT have not detected coronary artery calcinates in 34 patients. In one patient CI was 2 units by EBT and 0 units by MSCT. Mean CI by EBT was 499.4+/-598.2 units, by MSCT--533.7 +/-594.9 units (p = 0.8). The correlation coefficient between IV of the two methods was 0.976 (p < 0.0001). Mean difference between CI by both methods was 34.3 +/-133.6, variation coefficient 22%. There were differences between compatibility of CI in groups of patients with different CI, correlation and variation coefficients in dividing the patients into the subgroups depending on CI. In CI equal to 0-99 units EBT and MSCT correlation coefficient made up 0. 72, coefficient of variation 66%, in CI being 100-399 units these were 0.81 and 27%, in CI of 400-1000 units--0.85 and 16%, in CI exceeding 1000 units--0.95 and 0.4%, respectively. CONCLUSION. High IV correlation was found of MSCT and EBT for coronary artery calcinosis assay. Compatability of the MSCT and EBT data depends on CI