Cardiovascular magnetic resonance imaging for structural heart disease

Abstract

Cardiovascular magnetic resonance (CMR) has increasingly become a powerful imaging technique over the past few decades due to increasing knowledge about clinical applications, operator experience and technological advances, including the introduction of high field strength magnets, leading to improved signal-to-noise ratio. Its success is attributed to the free choice of imaging planes, the wide variety of imaging techniques, and the lack of harmful radiation. Developments in CMR have led to the accurate evaluation of cardiac structure, function and tissues characterisation, so this non-invasive technique has become a powerful tool for a broad range of cardiac pathologies. This review will provide an introduction of magnetic resonance imaging (MRI) physics, an overview of the current techniques and clinical application of CMR in structural heart disease, and illustrated examples of its use in clinical practice.

Compact pediatric cardiac magnetic resonance imaging protocols

“…Photograph shows specialized goggles (arrow), resting on an MRI table, which allow a child to view a movie during the exam to improve the experience pediatric cardiac MRI is performed for cardiomyopathy (to include myocarditis and viability studies) or CHD (encompassing valvular heart disease and aortopathies along with shunts and complex lesions) [28]. In cardiomyopathy, the main objectives are to establish cardiac morphology, ventricular volumetry/function ± mass, and myocardial tissue characterization [29]. In CHD, the exam generally includes an assessment of intracardiac and extracardiac anatomy and any complicating features (either presurgical or postoperative), ventricular volumetry/function ± mass, valvular function, and pertinent vascular flow measurements [30].…”

“…Cine images facilitate qualitative assessment of regional and global biventricular function. In addition, biventricular volumes and ejection fractions can be quantified by tracing biventricular endocardial contours (and epicardial contours, if myocardial mass measurements are needed) in end-diastole and end-systole using dedicated software [29,32]. LGE imaging allows for identification of areas of myocardial inflammation or fibrosis.…”

“…LGE imaging allows for identification of areas of myocardial inflammation or fibrosis. These are manifested as foci of high signal caused by the accumulation of gadolinium in tissues with increased extracellular volume fraction with resultant T1-shortening effects [29]. A sample compact cardiomyopathy MRI protocol with pertinent scan parameters at 1.5 T is shown in Table 1.…”

“…Cine imaging is made possible by capturing imaging data for multiple phases (time points) in the cardiac cycle. By averaging the data for each phase over multiple cardiac cycles in a typically single breath-hold acquisition, a highresolution of image of each phase can be reconstructed; displaying the images sequentially creates a movie ("cine") [29]. Cine imaging is achieved through the use of gradient echo (GRE) acquisitions, either spoiled gradient echo (SPGR) or balanced steady-state free precession (bSSFP) [29,30].…”

Quantitative Evaluation On Cardiac Remodeling Mechanism After Intensive Exercise: A Preliminary Study of Non-enhanced Cardiac Cine MRI

“…Recent studies suggest that CMR continues to have a unique advantage for detecting cardiac function ,and assessing focal and diffuse myocardial brosis [8]. Late gadolinium enhancements (LGEs) of CMR imaging for detecting myocardial brosis have a distinct advantage over other methods; however, a recent study has shown that gadolinium might be deposited in the skin, dentate nucleus, and globus pallidus of patients with normal renal function [9] .. Studies have shown that non-contrast-enhanced cardiac cine MRI was able to identify myocardial strain, a sensitive indicator of early cardiovascular dysfunction [10][11]. Non-contrast-enhanced cardiac cine MRI is a standard cardiac MRI examination method that can obtain end-diastolic volume index (EDVi) evaluations of left ventricular volume changes, myocardial mass index (Myo Mass) evaluations of overall quality changes, and mass-to-volume rate (MVR) evaluations of concentric circular remodeling of left ventricular myocardia [12].…”