Deep Learning-Based Image Registration in Dynamic Myocardial Perfusion CT Imaging.

Registration of dynamic CT image sequences is a crucial preprocessing step for clinical evaluation of multiple physiological determinants in the heart such as global and regional myocardial perfusion. In this work, we present a deformable deep learning-based image registration method for quantitative myocardial perfusion CT examinations, which in contrast to previous approaches, takes into account some unique challenges such as low image quality with less accurate anatomical landmarks, dynamic changes of contrast agent concentration in the heart chambers and tissue, and misalignment caused by cardiac stress, respiration, and patient motion. The introduced method uses a recursive cascade network with a ventricle segmentation module, and a novel loss function that accounts for local contrast changes over time. It was trained and validated on a dataset of n = 118 patients with known or suspected coronary artery disease and/or aortic valve insufficiency. Our results demonstrate that the proposed method is capable of registering dynamic cardiac perfusion sequences by reducing local tissue displacements of the left ventricle (LV), whereas contrast changes do not affect the registration and image quality, in particular the absolute CT (HU) values of the entire CT sequence. In addition, the deep learning-based approach presented reveals a short processing time of a few seconds compared to conventional image registration methods, demonstrating its application potential for quantitative CT myocardial perfusion measurements in daily clinical routine.

[4D FLOW Magnetic Resonance Imaging in the Study of Blood Flow in Patients With Aortic Coarctation in the Long-Term After Surgery].

Aim      Comprehensive evaluation of blood flow in the thoracic aorta using a software for 4D processing of magnetic resonance (MR) images of the heart and blood vessels (4D Flow) in patients with aortic coarctation in the late postoperative period.Materials and methods The MR study of the heart was performed for 10 patients (7 boys and 3 girls) aged 8 to 13 years (median, 9.5 [8.3; 10.8] years) who underwent resection with end-to-end anastomosis for aortic coarctation at age of 2 weeks to 10 months. MR tomography was performed on a 1.5 T MR scanner using a multichannel surface coil for scanning, electrocardiographic synchronization, and a specialized package of pulse sequences for scanning of the heart. Blood flow was evaluated with a 4D data handling software for processing of MR images of heart and blood vessels (4D Flow). The following blood flow parameters were analyzed: blood flow volume per second, peak blood flow velocity, peak and minimum blood flow area at the levels of ascending aorta, arch, isthmus, and descending aorta, and pressure gradient at the level of maximum narrowing of the aorta. 3D-MR images were used for evaluation of aortic geometry. Blood flow formation, distribution, and trajectories were analyzed by maps of vectors, particle trace, and stream lines. Statistical analysis was performed with a Statistica (v. 6.0 StatSoft Inc.) package.Results Accelerated flow in the region of residual aortic stenosis in systole was observed in all patients; 4 patients had an additional vortex flow below the aortic stenosis and a spiral flow in the descending aorta. The pressure gradient on the aortic isthmus was directly correlated with the left ventricular myocardial mass index (r=0.65; р=0.04) and indexes of blood flow in the ascending and descending aorta (р=0.03; р=0.026). No significant correlation was found for blood flow indexes and geometry of the aortic arch (H / L). Delayed contrast enhancement MR imaging did not detect any fibrotic changes in the myocardium in only one patient. The fibrosis severity inversely correlated with the right ventricular ejection fraction (r=0.65; р=0.04) and directly correlated with the pressure gradient at the aortic isthmus (r=0.63; p=0.05).Conclusion      The 4D MR image processing software for the heart and blood vessels allows studying the blood flow in detail under natural conditions, provides potential advantages in comprehensive evaluation of patients with aortic coarctation during a dynamic follow-up. For a definitive conclusion about the relationship between the altered blood flow in the thoracic aorta and markers of residual, post-correction pathology, larger studies are required as well as long-term follow-up of patients with documented pathological patterns of blood flow (changes in blood flow velocity and volume throughout the entire thoracic aorta in combination with disorders in the normal flow geometry during the cardiac cycle).

[Epicardial Fat and Atrial Fibrillation: the Role of Profibrinogenic Mediators].

BACKGROUND: Epicardial adipose tissue (EAT) has certain paracrine functions, which could be associated with proinflammatory and fibrotic changes in myocardium even in patients without structural heart disease but with atrial fibrillation (AF). PURPOSE: to evaluate interrelationship between clinical data, parameters of tissue Doppler imaging (TDI), EAT thickness estimated by magnetic resonance imaging (MRI), and biochemical markers of fibrosis and inflammation in patients with nonvalvular AF without concomitant ischemic heart disease (IHD). MATERIALS AND METHODS: We included in this study 39 AF patients without valvular pathology or IHD with normal or moderately increased left atrial (LA) dimension (mean age 50.8±13.9 years, 49 % men). The following groups were distinguished for analysis: with idiopathic AF (iAFgroup, n=21); with AF and arterial hypertension (AF+AH group, n=18); with normal (.

[Quantitative Evaluation of Intracardiac Blood Flow by Left Ventricle Dynamic Anatovy Based On Exact Solutions of Non-Stationary Navier-Stocks Equations for Selforganized tornado-Like Flows of Viscous Incompresssible Fluid].

New approach to intracardiac blood flow condition analysis based on geometric parameters of left ventricle flow channel has been suggested. Parameters, that used in this method, follow from exact solutions of nonstationary Navier-Stocks equations for selforganized tornado-like flows of viscous incompressible fluid. The main advantage of this method is considering dynamic anatomy of intracardiac cavity and trabeculae relief of left ventricle streamlined surface, both registered in a common mri-process, as flow condition indicator. Calculated quantity options that characterizes blood flow condition can be use as diagnostic criterias for estimation of violation in blood circulation function which entails heart ejection reduction. Developed approach allows to clarify heart jet organization mechanism and estimate the share of the tornado-like flow self-organization in heart ejection structure.

[Visualization of sinus node arteries by multislice spiral computed tomography coronary angiography].

OBJECTIVE: To assess the capabilities of multislice spiral computed tomography coronary angiography (MSCT-CA) to visualize the anatomy of the sinus node artery (SNA). MATERIAL AND METHODS: The retrospective analysis of coronary artery examinations covered 46 patients with the referral diagnosis of coronary heart disease. MSCT-CA showed no evidence of coronary artery stenosis. This sample included 23 (50%) men and 23 (50%) women; the mean age of the patients was 52.4 +/- 9.1 years; the mean height was 170 +/- 6.67 cm; the mean weight was 80.7 +/- 12.1 kg. X-ray computed tomography was carried out using a SOMATOM Definition AS+ 128-slice computed tomography scanner with retrospective ECG synchronization, reconstructed slice thicknesses of 1 and 3-mm. The Spearman correlation test was used for statistical data analysis. RESULTS: The SNA was visualized in 83% of the patients. It originated from the right coronary artery (RCA) and the circumflex branch of the left coronary artery in 84 and 16% of cases, respectively. No significant association was found between the type of heart blood supply and that of sinus node one (r = 0.06). In 18% of cases, the SNA was visualized only at the level of the ostium, allowing the assessment of the origin of the artery, and at the level of its mid-third in 32%; the distal SNA bed was visualized up to its division; in 10% of them the artery could be visualized all the way, including the division (the dissipation site). Unclear visualization of the proximal SNA was observed among 17% of the patients in whom the SNA could not be visualized with a heart rate (HR) of more than 80 beats/min in 62.5% of the patients, less than 41 beats/min in 12.5%, and 60-61 beats/min in 25%. HR was not found to be associated with the quality of SNA visualization (r = 0.09). CONCLUSION: MSCT can assess the anatomy of SNA up to the distal bed and dissipation site. In the overwhelming majority of the patients, the SNA originated from the RCA (84%) regardless of the type of heart blood supply. The best SNA visualization was noted with a HR of 50 to 80 beats per minute. There was no statistical relationship of the quality of visualization to HR.

[Computerized tomography in the diagnosis of congenital heart disease].

The aim of the work was to evaluate the possibility to use CT techniques (SCT and MRT) for the diagnosis of congenital heart disease. A total of 426 patient aged 0-54 years were examined (171 by MRT and 255 by SCT. SCT of the heart with bolus injection of a contrast medium was performed on an Evolution C-150 superfast tomograph in the step-scanning regime and prospective synchronization with ECG (slice thickness 1.5-3 mm). Fasting SCT was used to examine children in the first year of life during quiet (unforced) breathing. Contrast material (Omnipack-300, 350; Visipack-270, 320) was administered at a dose of 1.5-2.0 ml/ kg b.w. at 0.2-0.6 ml/s. MRT was performed using a conventional MR tomograph with a 1 T field and pulsed spin-echo sequences synchronized with ECG for obtaining the anatomic picture and gradient echo-signals (cine-MRT) for the assessment of functional parameters (slice thickness 4-7 mm). Babies were examined under medicamentous sedation. All images were treated and analysed using an Advantage Windows 2.0 workstation and a program package for heart image analysis. A rational procedure of CT and image analysis was developed in the course of the study. It provided data on the formation of all segments and intercommunications of the heart, mutual localization of its cavities and major vessels, permitted to perform morphometry of selected cardiac structures and detect anatomic defects. The informative and diagnostic value of methods for comprehensive evaluation of the heart and mediastinum in patients with congenital heart disease was assessed. Methods of choice for the diagnosis of abnormalities and follow-up of the patients in different periods after surgery were identified.

[Diagnostic algorithms and features of clinical course of congenital heart diseases in infants with lung anomalies].

The paper discusses the influence of lung anomalies on the progress of congenital heart diseases (CHD) in infants, as well as diagnostic value of radiography and ultraspeed computed tomography (CT). The four-year experience of the authors includes preoperative examination of 178 infants with CHD (mean age 5.8 +/- 0.6 months, mean weight 5.2 +/- 0.3 kg). Lung anomalies were determined in 24 patients (13.5%) on plain films and in 85 patients (47.8%)--by means of CT. The stenosis of main bronchi in combination with lobar emphysema and lung hypoplasia were found to be the most frequent and severe predictors of respiratory disorders. The obtained data suggest that CT examination may be recommended in infants with CHD for precise diagnostics of associated lung anomalies and further prevention or early management of respiratory complications.

[Spiral computed tomography in aortic aneurysm diagnostics].

10-year experience of use of spiral computed tomography (CT) with bolus intravascular contrasting allowed the authors to determine the advantages of this method in aortic aneurysm diagnostics and to show the importance of its application in dynamic monitoring. The article also covers drawbacks of the method, which are not so significant as the advantages, because the CT method answers practically all surgeon's questions, including the length, localization of aneurism, presence of congenital vascular anomalies, fistulas, hemorrhages or prosthesis infection in postoperative period. CT meets all the diagnostic requirements and bears minimal risk while quickly giving enough information about anomalies of bloodstream and surrounding tissues in a certain patient.

[Spiral computed tomography in the diagnosis of pathology of the vascular bed]. / Spiral'naia komp'iuternaia tomografiia v diagnostike patologii sosudistogo rusla.

The paper presents experience with spiral computed tomography used in the examination of 1000 patients. It analyzes the potentialities of CT angiography for the diagnosis of abnormality of the vascular bed. It is concluded that the use of the new method of X-ray contrast diagnosis is promising and expedient in clinical cardiovascular surgical care.