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Acquisition of Images There are several modes of 3DE acquisition; the appropriate mode must be decided based on the clinical question While the nomenclature of different modes is specific to each vendor, there are many shared features Enhanced Two-Dimensional Echocardiography Capabilities Matrix transducers enable rotation of the 2DE plane incrementally by 360 degrees They also allow for simultaneous acquisition and display of multiple orthogonal 2DE images that can be electronically steered in the lateral plane or the plane of elevation This mode can be used to assess the location, size and shape of atrial and ventricular septal defects, the morphology of valves and outflow tracts, and the nature of regurgitation (Fig 20.3, Video 20.4) FIG 20.3 Simultaneous two-dimensional echocardiography (2DE) color flow biplane view demonstrating a subarterial (supracristal, conal septal) ventricular septal defect in the parasternal long axis in the left panel, which is the reference image The operator can touch a single button to activate biplane (X-plane) mode, which defaults to an (adjustable) view that is rotated 90 degrees clockwise from the reference image In this case, the result is a simultaneous 2DE color flow demonstration of the ventricular septal defect in both a parasternal long-axis view and parasternal shortaxis view, with a frame rate of 24 frames per second LA, Left atrium; MV, mitral valve; RA, right atrium; TV, tricuspid valve Real-Time or Live Three-Dimensional Echocardiography Live 3DE provides a narrow, adjustable pyramidal volume of data It minimizes the potential for motion and artefacts that are seen with other modes of 3DE, as described below Acceptable temporal resolution with live 3DE comes at the expense of field of view, which can be a disadvantage in complex defects where multiple spatial relationships need to be determined Cardiac structures that are relatively static, such as atrial or ventricular septal defects, lend themselves well to live 3DE and are particularly useful when guiding interventions, for example Some vendors allow adjustments to prioritize temporal resolution at the expense of line density Electrocardiographically Gated Acquisitions Over Multiple Beats (Full Volumes) Full volume 3DE provides a wide pyramidal 3DE volume that is acquired over multiple consecutive cardiac cycles Full volumes are frequently used in pediatric imaging because they allow the acquisition of a sufficiently large field of view with good temporal resolution In young children, these datasets are prone to artefacts related to breathing and other movement This is not an issue in children who can hold their breath or are being ventilated under general anesthesia because ventilation can be briefly suspended While the capability to acquire a full volume of data over a single cardiac cycle is now available, the current temporal resolution of this latter mode is not acceptable in children Three-Dimensional Color Flow A pyramidal acquisition of 3DE color flow is obtained within a larger acquisition of grayscale data To ensure adequate temporal resolution, these acquisitions have to be performed over several cardiac cycles ... Full volume 3DE provides a wide pyramidal 3DE volume that is acquired over multiple consecutive cardiac cycles Full volumes are frequently used in pediatric imaging because they allow the acquisition of a sufficiently large field of view with good temporal resolution
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