Identification of weakly coupled multiphysics problems. Application to the inverse problem of electrocardiography

This work addresses the inverse problem of electrocardiography from a new perspective, by combining electrical and mechanical measurements. Our strategy relies on the defini-tion of a model of the electromechanical contraction which is registered on ECG data but also on measured mechanical displacements of the heart tissue typically extracted from medical images. In this respect, we establish in this work the convergence of a sequential estimator which combines for such coupled problems various state of the art sequential data assimilation methods in a unified consistent and efficient framework. Indeed we ag-gregate a Luenberger observer for the mechanical state and a Reduced Order Unscented Kalman Filter applied on the parameters to be identified and a POD projection of the electrical state. Then using synthetic data we show the benefits of our approach for the estimation of the electrical state of the ventricles along the heart beat compared with more classical strategies which only consider an electrophysiological model with ECG measurements. Our numerical results actually show that the mechanical measurements improve the identifiability of the electrical problem allowing to reconstruct the electrical state of the coupled system more precisely. Therefore, this work is intended to be a first proof of concept, with theoretical justifications and numerical investigations, of the ad-vantage of using available multi-modal observations for the estimation and identification of an electromechanical model of the heart

On motion in dynamic magnetic resonance imaging: Applications in cardiac function and abdominal diffusion

La imagen por resonancia magnética (MRI), hoy en día, representa una potente herramienta para el diagnóstico clínico debido a su flexibilidad y sensibilidad a un amplio rango de propiedades del tejido. Sus principales ventajas son su sobresaliente versatilidad y su capacidad para proporcionar alto contraste entre tejidos blandos. Gracias a esa versatilidad, la MRI se puede emplear para observar diferentes fenómenos físicos dentro del cuerpo humano combinando distintos tipos de pulsos dentro de la secuencia. Esto ha permitido crear distintas modalidades con múltiples aplicaciones tanto biológicas como clínicas. La adquisición de MR es, sin embargo, un proceso lento, lo que conlleva una solución de compromiso entre resolución y tiempo de adquisición (Lima da Cruz, 2016; Royuela-del Val, 2017). Debido a esto, la presencia de movimiento fisiológico durante la adquisición puede conllevar una grave degradación de la calidad de imagen, así como un incremento del tiempo de adquisición, aumentando así tambien la incomodidad del paciente. Esta limitación práctica representa un gran obstáculo para la viabilidad clínica de la MRI. En esta Tesis Doctoral se abordan dos problemas de interés en el campo de la MRI en los que el movimiento fisiológico tiene un papel protagonista. Éstos son, por un lado, la estimación robusta de parámetros de rotación y esfuerzo miocárdico a partir de imágenes de MR-Tagging dinámica para el diagnóstico y clasificación de cardiomiopatías y, por otro, la reconstrucción de mapas del coeficiente de difusión aparente (ADC) a alta resolución y con alta relación señal a ruido (SNR) a partir de adquisiciones de imagen ponderada en difusión (DWI) multiparamétrica en el hígado.Departamento de Teoría de la Señal y Comunicaciones e Ingeniería TelemáticaDoctorado en Tecnologías de la Información y las Telecomunicacione

Bioimage Data Analysis Workflows

This Open Access textbook provides students and researchers in the life sciences with essential practical information on how to quantitatively analyze data images. It refrains from focusing on theory, and instead uses practical examples and step-by step protocols to familiarize readers with the most commonly used image processing and analysis platforms such as ImageJ, MatLab and Python. Besides gaining knowhow on algorithm usage, readers will learn how to create an analysis pipeline by scripting language; these skills are important in order to document reproducible image analysis workflows. The textbook is chiefly intended for advanced undergraduates in the life sciences and biomedicine without a theoretical background in data analysis, as well as for postdocs, staff scientists and faculty members who need to perform regular quantitative analyses of microscopy images

Towards automating cine DENSE MRI image analysis : segmentation, tissue tracking and strain computation

Includes bibliographical references (p. 192-206).Over the past two decades, magnetic resonance imaging (MRI) has developed into a powerful imaging tool for the heart. Imaging cardiac morphology is now commonplace in clinical practice, and a plethora of quantitative techniques have also arisen on the research front. Myocardial tagging is an established quantitative cardiac MRI method that involves magnetically tagging the heart with a set of saturated bands, and monitoring the deformation of these bands as the heart contracts

State-of-the art of acousto-optic sensing and imaging of turbid media

Acousto-optic (AO) is an emerging hybrid technique for measuring optical contrast in turbid media using coherent light and ultrasound (US). A turbid object is illuminated with a coherent light source leading to speckle formation in the remitted light. With the use of US, a small volume is selected,which is commonly referred to as the “tagging” volume. This volume acts as a source of modulated light, where modulation might involve phase and intensity change. The tagging volume is created by focusing ultrasound for good lateral resolution; the axial resolution is accomplished by making either the US frequency, amplitude, or phase time-dependent. Typical resolutions are in the order of 1 mm. We will concentrate on the progress in the field since 2003. Different schemes will be discussed to detect the modulated photons based on speckle detection, heterodyne detection, photorefractive crystal (PRC) assisted detection, and spectral hole burning (SHB) as well as Fabry-Perot interferometers. The SHB and Fabry-Perot interferometer techniques are insensitive to speckle decorrelation and therefore suitable for in vivo imaging. However, heterodyne and PRC methods also have potential for in vivo measurements. Besides measuring optical properties such as scattering and absorption, AO can be applied in fluorescence and elastography applications

Flow Imaging Using MRI: Quantification and Analysis

A complex and challenging problem in flow study is to obtain quantitative flow information in opaque systems, for example, blood flow in biological systems and flow channels in chemical reactors. In this regard, MRI is superior to the conventional optical flow imaging or ultrasonic Doppler imaging. However, for high speed flows, complex flow behaviors and turbulences make it difficult to image and analyze the flows. In MR flow imaging, MR tagging technique has demonstrated its ability to simultaneously visualize motion in a sequence of images. Moreover, a quantification method, namely HARmonic Phase (HARP) analysis, can extract a dense velocity field from tagged MR image sequence with minimal manual intervention. In this work, we developed and validated two new MRI methods for quantification of very rapid flows. First, HARP was integrated with a fast MRI imaging method called SEA (Single Echo Acquisition) to image and analyze high velocity flows. Second, an improved HARP method was developed to deal with tag fading and data noise in the raw MRI data. Specifically, a regularization method that incorporates the law of flow dynamics in the HARP analysis was developed. Finally, the methods were validated using results from the computational fluid dynamics (CFD) and the conventional optimal flow imaging based on particle image velocimetry (PIV). The results demonstrated the improvement from the quantification using solely the conventional HARP method

Hierarchical template matching for 3D myocardial tracking and cardiac strain estimation

Myocardial tracking and strain estimation can non-invasively assess cardiac functioning using subject-specific MRI. As the left-ventricle does not have a uniform shape and functioning from base to apex, the development of 3D MRI has provided opportunities for simultaneous 3D tracking, and 3D strain estimation. We have extended a Local Weighted Mean (LWM) transformation function for 3D, and incorporated in a Hierarchical Template Matching model to solve 3D myocardial tracking and strain estimation problem. The LWM does not need to solve a large system of equations, provides smooth displacement of myocardial points, and adapt local geometric differences in images. Hence, 3D myocardial tracking can be performed with 1.49 mm median error, and without large error outliers. The maximum error of tracking is up to 24% reduced compared to benchmark methods. Moreover, the estimated strain can be insightful to improve 3D imaging protocols, and the computer code of LWM could also be useful for geo-spatial and manufacturing image analysis researchers

MR imaging of left-ventricular function : novel image acquisition and analysis techniques.

Many cardiac diseases, such as myocardial ischemia, secondary to coronary artery disease, may be identified and localized through the analysis of cardiac deformations. Early efforts for quantifying ventricular wall motion used surgical implantation and tracking of radiopaque markers with X-ray imaging in canine hearts [1]. Such techniques are invasive and affect the regional motion pattern of the ventricular wall during the marker tracking process and, clearly are not feasible clinically. Noninvasive imaging techniques are vital and have been widely applied to the clinic. MRI is a noninvasive imaging technique with the capability to monitor and assess the progression of cardiovascular diseases (CVD) so that effective procedures for the care and treatment of patients can be developed by physicians and researchers. It is capable of providing 3D analysis of global and regional cardiac function with great accuracy and reproducibility. In the past few years, numerous efforts have been devoted to cardiac motion recovery and deformation analysis from MR imaging sequences. In order to assess cardiac function, there are two categories of indices that are used: global and regional indices. Global indices include ejection fraction, cavity volume, and myocardial mass [2]. They are important indices for cardiac disease diagnosis. However, these global indices are not specific for regional analysis. A quantitative assessment of regional parameters may prove beneficial for the diagnosis of disease and evaluation of severity and the quantification of treatment [3]. Local measures, such as wall deformation and strain in all regions of the heart, can provide objective regional quantification of ventricular wall function and relate to the location and extent of ischemic injury. This dissertation is concerned with the development of novel MR imaging techniques and image postprocessing algorithms to analyze left ventricular deformations. A novel pulse sequence, termed Orthogonal CSPAMM (OCSPAMM), has been proposed which results in the same acquisition time as SPAMM for 2D deformation estimation while keeping the main advantages of CSPAMM [4,5]: i.e., maintaining tag contrast through-out the ECG cycle. Different from CSPAMM, in OCSPAMM the second tagging pulse orientation is rotated 90 degrees relative to the first one so that motion information can be obtained simultaneously in two directions. This reduces the acquisition time by a factor of two as compared to the traditional CSPAMM, in which two separate imaging sequences are applied per acquisition. With the application of OCSPAMM, the effect of tag fading encountered in SPAMM tagging due to Tl relaxation is mitigated and tag deformations can be visualized for the entire cardiac cycle, including diastolic phases. A multilevel B-spline fitting method (MBS) has been proposed which incorporates phase-based displacement information for accurate calculation of 2D motion and strain from tagged MRI [6, 7]. The proposed method combines the advantages of continuity and smoothness of MBS, and makes use of phase information derived from tagged MR images. Compared to previous 2D B-spline-based deformation analysis methods, MBS has the following advantages: 1) It can simultaneously achieve a smooth deformation while accurately approximating the given data set; 2) Computationally, it is very fast; and 3) It can produce more accurate deformation results. Since the tag intersections (intersections between two tag lines) can be extracted accurately and are more or less distributed evenly over the myocardium, MBS has proven effective for 2D cardiac motion tracking. To derive phase-based displacements, 2D HARP and SinMod analysis techniques [8,9] were employed. By producing virtual tags from HARP /SinMod and calculating intersections of virtual tag lines, more data points are obtained. In the reference frame, virtual tag lines are the isoparametric curves of an undeformed 2D B-spline model. In subsequent frames, the locations of intersections of virtual tag lines over the myocardium are updated with phase-based displacement. The advantage of the technique is that in acquiring denser myocardial displacements, it uses both real and virtual tag line intersections. It is fast and more accurate than 2D HARP and SinMod tracking. A novel 3D sine wave modeling (3D SinMod) approach for automatic analysis of 3D cardiac deformations has been proposed [10]. An accelerated 3D complementary spatial modulation of magnetization (CSPAMM) tagging technique [11] was used to acquire complete 3D+t tagged MR data sets of the whole heart (3 dynamic CSPAMM tagged MRI volume with tags in different orientations), in-vivo, in 54 heart beats and within 3 breath-holds. In 3D SinMod, the intensity distribution around each pixel is modeled as a cosine wave front. The principle behind 3D SinMod tracking is that both phase and frequency for each voxel are determined directly from the frequency analysis and the displacement is calculated from the quotient of phase difference and local frequency. The deformation fields clearly demonstrate longitudinal shortening during systole. The contraction of the LV base towards the apex as well as the torsional motion between basal and apical slices is clearly observable from the displacements. 3D SinMod can automatically process the image data to derive measures of motion, deformations, and strains between consecutive pair of tagged volumes in 17 seconds. Therefore, comprehensive 4D imaging and postprocessing for determination of ventricular function is now possible in under 10 minutes. For validation of 3D SinMod, 7 3D+t CSPAMM data sets of healthy subjects have been processed. Comparison of mid-wall contour deformations and circumferential shortening results by 3D SinMod showed good agreement with those by 3D HARP. Tag lines tracked by the proposed technique were also compared with manually delineated ones. The average errors calculated for the systolic phase of the cardiac cycles were in the sub-pixel range

Evaluation of left ventricle strains by applying SPAMM cardiac MRI techniques

Tese de mestrado integrado em Engenharia Biomédica e Biofísica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2017As doenças cardiovasculares são uma das maiores causas de morte no mundo, causando aproximadamente 17.5 milhões de mortes por ano, o que corresponde a 31% de todas as mortes no mundo. Estas doenças caracterizam-se pela diminuição da contração da parede do miocárdio durante o ciclo cardíaco. Uma das doenças mais comuns é a cardiomiopatia dilatada (DCM), onde o músculo cardíaco fica mais fino e fraco, e as cavidades cardíacas ficam aumentadas. Consequentemente, a capacidade de deformação do miocárdio é diminuída, o que impossibilita o coração de bombear eficientemente o sangue para as restantes partes do corpo. Esta condição é maioritariamente genética, mas também pode ser provocada por diferentes causas como infeções virais, inflamações ou lesões. A análise da deformação da parede do miocárdio aquando do ciclo cardíaco possibilita não só a identificação das deformações normais do miocárdio aquando da sua contração, mas também das deformações anormais devido a doenças cardíacas. A técnica de ressonância magnética cardíaca (CMR) é não invasiva e tem uma elevada resolução espacial, sendo por isso indispensável no estudo destas deformações. Esta técnica permite detetar essas mesmas características da contração e distensão do músculo cardíaco, possibilitando a análise das deformações e a respetiva distinção entre os pacientes saudáveis e os pacientes com cardiomiopatia dilatada. Nesta doença, observa-se o estreitamento das paredes do miocárdio e a dilatação das cavidades cardíacas, como é o caso do ventrículo esquerdo, o que se observa pelo aumento do seu diâmetro. O resultado é um decréscimo significativo na tensão e deformação da parede do miocárdio, o que impacta negativamente na eficiência da sístole ventricular. A técnica de Modulação Espacial da Magnetização (SPAMM) tem vindo a ser proposta para a visualização do movimento e deslocamento da parede do miocárdio no seu plano de imagem, através da criação de padrões de linhas e grelhas com magnetização alterada na imagem. Estes padrões são marcadores que seguem a deformação do músculo cardíaco. Ao serem detetados e seguidos durante o ciclo cardíaco, estes marcadores contribuem para o estudo do movimento da parede do miocárdio aquando da sua contração. A amostra usada nesta tese consistiu em imagens de ressonância magnética cardíaca de 9 indivíduos, 3 dos quais são saudáveis e os outros 6 são pacientes com DCM. As imagens foram adquiridas pelo Hospital Motol em Praga (República Checa) e analisadas pelo Instituto de Informática, Robótica and Cibernética da Faculdade de Engenharia Elétrica em Praga. A tese proposta teve como objetivo o estudo da deformação radial no ventrículo esquerdo através da automatização na deteção dos marcadores presentes no mesmo, assim como no seu seguimento ao longo do ciclo cardíaco. Pela análise das deformações de voluntários saudáveis e de pacientes com cardiomiopatia dilatada, é possível comparar os seus padrões de deformação cardíaca de modo a analisar as diferenças entre os dois. Pelo estudo das deformações, sabe-se que um valor positivo de deformação corresponde a um espessamento de um objeto e um valor negativo corresponde ao seu encurtamento, relativamente ao seu tamanho inicial. Durante a contração do miocárdio, é normal observar-se um espessamento e encurtamento da parede do ventrículo esquerdo. Assim sendo, as deformações radiais tomam valores positivos devido ao espessamento da parede e as circunferenciais tomam valores negativos devido ao encurtamento da parede. Os métodos de deteção dos marcadores foram aplicados com sucesso nos sujeitos saudáveis e com cardiomiopatia dilatada, sendo que estes marcadores foram também corretamente seguidos ao longo do ciclo cardíaco, durante a sístole e a diástole. Nos sujeitos saudáveis, foi observado um intervalo de deformações radiais entre 18.63 % e 43.84 %, enquanto que em pacientes com cardiomiopatia dilatada, os valores de deformação radial variaram entre 10.73 % e 14.14 %. De notar que os valores das deformações radiais são positivos e, por isso, confirmam o espessamento da parede do ventrículo esquerdo aquando da sua contração. Assim sendo, os resultados desta dissertação vão de encontro com os resultados dos testes feitos anteriormente em voluntários saudáveis e com cardiomiopatia dilatada, visto que os intervalos de deformações são semelhantes para os dois grupos. Ao comparar-se as deformações dos dois grupos pelo teste estatístico Mann-Whitney, verificou-se uma diferença significativa (p<0.05) nos valores das deformações entre os mesmos. Assim sendo, esta tese também confirma que os pacientes com a doença cardíaca têm valores mais baixos de deformação em relação aos indivíduos saudáveis, tal como é comprovado pelo facto da doença cardiomiopatia dilatada ser caracterizada pela diminuição da deformação do miocárdio durante o ciclo cardíaco. Pela comparação dos diferentes segmentos ao longo das secções básica, média e apical do ventrículo esquerdo, foi também observado que nos pacientes com cardiomiopatia dilatada, a deformação mínima correspondeu ao segmento inferolateral da base do ventrículo e que a deformação máxima se deu no segmento anteroseptal da secção média do ventrículo. Em contrapartida, nos indivíduos saudáveis, o mínimo da deformação foi no segmento anterior e o máximo da deformação correspondeu ao segmento inferoseptal, ambos os segmentos pertencentes à secção média do ventrículo esquerdo. Estes resultados foram também observados em estudos anteriores relativos a pacientes com cardiomiopatia dilatada. Relativamente à análise das deformações circunferenciais, foi observado que, nos sujeitos saudáveis, o intervalo das deformações esteve entre -32.17 % e -24.33 %, enquanto que nos pacientes com cardiomiopatia dilatada, o intervalo foi de -15.92 % a -8.17 %. O valor negativo da deformação circunferencial é devido ao encurtamento da parede do ventrículo esquerdo, sendo que este valor se encontra em conformidade com o correto comportamento da parede do ventrículo durante a contração do miocárdio, tal como observado em estudos anteriores. Para alem destes factos, também se verificou que o máximo da deformação circunferencial foi dado na secção media do ventrículo esquerdo, enquanto que o mínimo foi na secção apical do mesmo. Ao comparar-se as deformações circunferenciais, pelo teste estatístico Mann-Whitney, durante a systole e entre os dois grupos de sujeitos, verificou-se existe uma diminuição significativa (p<0.05) do seu valor absoluto nos pacientes, relativamente aos sujeitos saudáveis. Adicionalmente, também foi estudado o efeito do género (masculino / feminino) nas deformações dos pacientes com cardiomiopatia dilatada. Os resultados do estudo mostraram que as deformações do ventrículo esquerdo são maiores no género masculino, em relação ao género feminino. Contudo, outros estudos realizados anteriormente não relataram qualquer relação entre as deformações do miocárdio e o género (masculino / feminino) dos respetivos pacientes. Com esta dissertação foi possível concluir que o estudo das deformações no ventrículo esquerdo é um parâmetro importante na avaliação da contratilidade do coração. O facto de a Ressonância magnética ser uma técnica não invasiva e da técnica de Modulação espacial da magnetização permitir criar um padrão de grelha que facilmente acompanha movimentos na parede do músculo, possibilitou a eficiente deteção das deformações na parede do ventrículo esquerdo. Uma outra conclusão importante deste estudo é o facto da doença cardiomiopatia dilatada provocar uma diminuição da capacidade de deformação do coração, visto que a doença é caracterizada pelo estreitamento da parede do miocardio e por uma dilatação das cavidades cardíacas, especialmente dos ventrículos. Este facto está na origem da diminuição das deformações radiais e circunferenciais, em relação às deformações dos pacientes saudáveis. Foi também observado que a secção do ventrículo esquerdo responsável pela maior deformação é a secção média, pois foi nesta secção que se observou um maior número de valores máximos de deformação. Por fim, nesta tese também se confirma que durante a contração do miocárdio, a deformação radial teve valores positivos e a deformação circunferencial teve valores negativos, o que comprova que houve um espessamento e encurtamento da parede do ventrículo esquerdo durante a sua contração. Assim sendo, verifica-se que ao longo desta dissertação foi possível analisar a relação da deformação do ventrículo esquerdo com a doença cardiomiopatia dilatada e consequentemente, avaliar se a deformação calculada é normal ou devido à doença cardíaca. Como tal, a partir deste estudo foi possível facilitar a deteção das deformações, bem como fazer a sua análise para contribuição do estudo das doenças cardíacas, tal como a cardiomiopatia dilatada. Como trabalho futuro, poderá estudar-se como detetar automaticamente o ventrículo esquerdo e como calcular eficientemente as suas deformações. Assim, poderá também aprofundar-se o estudo e a análise da doença cardiomiopatia dilatada e de outras doenças cardíacas.Cardiovascular diseases are one of the main causes of death in the world. These diseases modify the myocardial wall contraction during cardiac cycle. One of the most common types of these diseases is the dilated cardiomyopathy (DCM), in which the heart muscle becomes weaker and the heart cavities are enlarged. Consequently, the heart deformation capability is decreased, which prevents it from pumping blood efficiently. This condition can be genetic or due to various causes such as viral infections, inflammation or injuries. The analysis of cardiac wall deformation enables identifying normal or abnormal deformations due to heart disease. Cardiac Magnetic Resonance Imaging (MRI) is able to detect the characteristic abnormalities of DCM, which are the wall thinning and dilation of heart chambers, more specifically the increasing of ventricle diameter. The result is a significant decrease in wall stress and strain, which has a negative impact on systolic ventricular performance. The Spatial Modulation of Magnetization (SPAMM) technique has been proposed for imaging myocardial motion within the plane of the image by creating a pattern of lines or grids with altered magnetization on the image. These patterns are tags that deform according to the heart muscle deformation and can be detected and tracked for wall motion studying. The sample used in this thesis was composed by cardiac MRI scans of 9 subjects, 3 of which were healthy subjects and the other 6 were patients with DCM. The scans were acquired by Motol Hospital in Prague (Czech Republic) and analyzed in the Institute of Informatics, Robotics and Cybernetics from the Faculty of Electrical Engineering in Prague. The proposed thesis intended to assess the left ventricle (LV) radial and circumferential strains by automatically detecting LV tags and tracking those during cardiac cycle. By analyzing the heart strains from healthy subjects and patients with DCM, it is possible to compare both patterns of cardiac deformation within the cardiac cycle in order to analyze the differences between them. Positive strain values describe myocardial thickening and negative values describe its shortening, related to its original length. During myocardial contraction, the radial strain is positive due to myocardial thickening, and the circumferential strain is negative due to myocardial shortening. The tracking methods were successfully applied on heathy and DCM patients and the tags were successfully detected during systole and diastole. A comparison between the strains, by Mann-Whitney statistical test, during the cardiac cycle in both sets of subjects, identified a significant difference (p<0.05) between them. It was observed that in healthy subjects, the radial strain varied from 18.63 % to 43.84 %, while in DCM patients, the radial strain varied from 10.73 % to 14.14 %. The radial strains are positive values, as the LV thickens during myocardial contraction. The results of this thesis are in agreement with previous studies done with DCM and healthy subjects, as the ranges of deformations are similar in both sets of subjects. Moreover, this thesis also confirms that DCM patients have lower radial strain values than healthy subjects, as DCM is characterized by a decrease in heart muscle strain during the cardiac cycle. By comparing several segments in the different sections of the heart, it was also observed that in DCM patients, the minimum deformation was on the inferolateral segment of the base, while the maximum was on the anteroseptal segment of the middle section. However, in healthy subjects, the minimum deformation was on the anterior segment and the maximum was on the inferoseptal segment, both in the middle section of the left ventricle. This result was also observed in previous studies. Regarding to the circumferential strains analysis, it was observed that in healthy subjects, the average circumferential strain range was from -32.17 % to -24.33 %, while in DCM patients, it was from -15.92 % to -8.17 %. The negative value of the circumferential strain means that there was a LV wall shortening and this is in conformity with the correct behavior of LV during myocardial contraction. Moreover, in healthy subjects, the mid section of LV has the major strain, while in DCM patients, it is the apical section. A comparison between the circumferential strains during systole in both sets of subjects supports the previous studies results, in which the circumferential stains values are negative during systole. Additionally, the results of Mann-Whitney statistical test also shown significant lower absolute (p<0.05) values on DCM patients, when comparing to healthy subjects. Additionally, the effect of the gender (male/ female) on the strains was also investigated on the DCM patients and the results suggest that in women, the LV strain is lower than in men. Despite these results, the other studies did not report any conclusion related to this effect. It is possible to state that the study of the LV strain is an important parameter in the evaluation of the cardiac contractility. A non-invasive assessment of LV by MRI and the superimposed grid created by SPAMM improved the tracking of LV wall strains. Another important conclusion of this study was that DCM decreases the deformation capabilities of the heart, as it is responsible for the wall thinning and dilation of heart chambers, causing a decrease in wall radial and circumferential strains. Moreover, it was observed that the major section responsible for the myocardial deformation was the middle section of the LV. Finally, this thesis also confirmed that during myocardial contraction, the radial strain values are positive due to the myocardial thickening and the circumferential values are negative due to the myocardial shortening. A need to automatically detect the LV and also to efficiently calculate the LV strains in a short time can be developed as a future work, which will also improve the analysis of DCM disease and other cardiac diseases