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Cardiac magnetic resonance imaging.
Also known as cardiac MRI, is a medical imaging technology for non-invasive assessment of the function and structure of the cardiovascular system.
CMRI sequences are adapted for cardiac imaging by using ECG gating and high temporal resolution protocols.
CMRI is complementary to other imaging techniques, such as echocardiography, cardiac CT, and nuclear medicine.
Cardiac magnetic resonance imaging (MRI), also known as cardiovascular magnetic resonance (CMR), is a non-invasive imaging modality that provides detailed information about the structure and function of the heart.
It uses a magnetic field and radio waves to create high-resolution images of the heart and surrounding structures.
CMR is considered a standard for assessing ventricular volumes, systolic function, and myocardial tissue characterization.
It is particularly useful in evaluating a wide range of cardiovascular conditions, including ischemic heart disease, cardiomyopathies, valvular heart disease, congenital heart disease, and pericardial disease.
It has the ability to accurately assess global and regional ventricular function, detect myocardial ischemia and infarction, and determine myocardial viability.
It can also identify myocardial edema and microvascular obstruction, to help differentiating acute from chronic myocardial infarction and other causes of acute chest pain, such as myocarditis.
CMR uses various imaging techniques: cine imaging for functional assessment, late gadolinium enhancement (LGE) for detecting myocardial fibrosis and scarring, and T2 imaging for assessing iron overload.
Gadolinium-based contrast agents enhance the visualization of myocardial tissue characteristics and perfusion.
Overall, CMR provides critical information that can guide therapeutic decisions and improve patient outcomes.
Applications include assessment of myocardial ischemia and viability, cardiomyopathies, myocarditis, iron overload, vascular diseases, and congenital heart disease.
Cardiac MRI in cases of clinically suspected myocarditis should be performed within 2 to 3 weeks after initial presentation and is useful for its diagnostic sensitivity and for assessment and follow up to monitor the evolution of the disease.
It is valuable for diagnosis and surgical approach in complex congenital heart disease.
It can detect and characterize myocardial ischemia due to disease affecting the epicardial vessels and microvasculature.
Cardiac MRI is the gold standard for noninvasive assessment of LV volumes and LVEF because if it’s high accuracy and reproducibility.
Gadolinium enhancement and T1 mapping allow infarction and fibrosis to be identified for characterizing cardiomyopathy and assessing myocyte viability.
Can be used to assess congenital or acquired abnormalities of the coronary arteries and great vessels.
It avoids ionizing radiation.
Gadolinium based contrast medium is frequently used in CMR and has been associated with nephrogenic systemic fibrosis.
Intra-cranial deposition of gadolinium has been demonstrated..
Imaging of the cardiovascular system is usually performed with cardiac gating using an adaptation of conventional ECG techniques.
T1-weighted sequences are used to visualize anatomy and detect the presence of intra-myocardial fat, and to quantify diffuse myocardial fibrosis.
T2-weighted imaging is primarily used to detect myocardial edema which may be seen in acute myocarditis or infarction.
Phase-contrast imaging is used to assess valve disease and quantify shunts.
Contrast medium is given intravenously to assess myocardial perfusion.
It can provide information about the nature of congenital hearts defects without using x-rays or being invasive.
In congenital heart disease it is typically used with other diagnostic techniques.
Use of CMRI: when echocardiography cannot provide sufficient diagnostic information, as an alternative to diagnostic cardiac catheterization which involve risks including x-ray radiation exposure, to obtain diagnostic information for which CMR offers unique advantages such as blood flow measurement or identification of cardiac masses, and when clinical assessment and other diagnostic tests are inconsistent.
Conditions in which CMRI is often used include: tetralogy of Fallot, transposition of the great arteries, coarctation of the aorta, single ventricle heart disease, abnormalities of the pulmonary veins, atrial septal defect, connective tissue diseases such as Marfan syndrome, vascular rings, abnormal origins of the coronary arteries, and cardiac tumors.