الفهرس 
EMBRYOLOGYOnly 14 pages are availabe for public view
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Abstract
Congenital heart disease (CHD) is a relatively common problem, with an incidence of approximately5 to 12 per 1000 live births. Over the past two decades, the trend has been to perform more types of surgical repair at infancy, even after operative repair, many of these patients have residual anatomic defects and require close longitudinal follow-up.
MRI has emerged as an important and growing means of cardiovascular imaging with many advantages over other radiological modalities including the ability to display large field of view, to produce image in any desired plane with excellent spatial and temporal resolution, lake of ionizing radiation and noninvasiveness.
Evaluation of congenital heart disease (CHD) is an important application of Cardiac MRI since the morphological details of chambers, septum, defects and anomalous connections are depicted accurately. Besides, flow information across valves, chambers, outflow tracts and shunts are also provided.
Cardiovascular MR imaging provides both morphologic and functional information that can be decisive in the treatment of neonates and infants with CHD. Excellent-quality MR images can be obtained when the technical parameters of the pulse sequences are adjusted to the small size an fast heart rates of these patients The capacity of MR imaging to accurately demonstrate complex abnormalities of the entire thoracic vasculature can obviate potentially harmful cardiac catheterization in many cases.
MRI is useful for evaluating the anatomy of the cardiac chambers and great vessels by two features: the lack of signal intensity from flowing blood (signal void), which provides excellent contrast between the lumen and the myocardium or vessel wall and the simultaneous visualization of several (or all) cardiac components on multiple plane tomographic image
In infant and neonates, echocardiography is the initial imaging modality of choice. Later on, especially after surgery, when scar tissue around the heart impedes ultrasound penetration and echocardiographic views are suboptimal, CMRI is the preferred imaging method.
Cardiac MRI is a powerful tool for complete characterization of congenital anatomy. Black-blood, white blood cine and 3D angiography offer complementary insights into congenital pathophysiology. Black-blood imaging offers superior resolution, contrast, and decreased sensitivity to metal artifacts. White blood cine imaging provides physiologic context to the anatomy, demonstrating flow patterns, valve motion, qualitative assessment of stenosis, regurgitation, and cardiac function. Contrast-enhanced MR angiography offers depiction of small vessel disease while also yielding the best 3D representations of vessel relationships.