Three-dimensional (3D) echocardiography has rapidly grown in the past decades with several technological breakthroughs in scanner design, beam forming, image acquisition, and display as well as quantification. It has allowed for a better understanding of cardiovascular pathology and has established new standards for imaging and diagnosis. Although it is unlikely to replace two-dimensional (2D) echocardiography, the rapid technological advancements and its continuously growing potential will make 3D echocardiography the imaging modality of choice in clinical practice in the future.
In this chapter, we discuss the role of 3D echocardiography in the perioperative period.
EVOLUTION OF THREE-DIMENSIONAL ECHOCARDIOGRAPHY
Three-dimensional echocardiography has a long history, with the first 3D reconstruction of 2D images described in 1974 and the first human 3D transesophageal echocardiogram (TEE) performed in 1992.1,2 Before the technology required for real-time (RT) scanning of multiple planes was developed, 3D imaging of the heart was attempted by the use of linear step-by-step movement of the transducer by means of a motorized device.3 An alternative approach to linear scanning was to maintain the TEE transducer in a fixed position and rotate the imaging plane by internally steering the imaging element in a different direction4 or to rotate the transthoracic echocardiography (TTE) transducer several degrees at a time using a motorized device.5 A crucial development in 3D reconstruction was sequential gated acquisition. This technique allowed acquisition of different cut planes with gating to minimize artifacts and combining all these different planes to create a 3D image of the heart. Respiratory and electrocardiogram (ECG) gating could be used to minimize spatial and temporal misalignment. In order to minimize spatial misalignment, the use of spatial locators using a technology similar to the global positioning system was used to determine the exact location and orientation of the transducer at any moment by having these devices communicate with a receiver unit inside the examination room.6 Irrespective of the technology used, these earlier approaches were limited by time-consuming acquisition and reconstruction processes (15 to 30 minutes), frequent artifacts, and the need for offline processing. As a consequence, reconstructive 3D-TEE primarily remained a research tool and did not make it into routine clinical practice.
The realization that scanning volumes rather than isolated cut volumes would circumvent many of the disadvantages of 3D reconstruction led to the development of the first RT 3D system equipped with a phased-array transducer. The phased-array technology permitted the piezoelectric elements arranged in multiple rows to be electronically steered not only within a single plane but also in a lateral direction. The first-generation RT 3D system had a matrix-array transducer with 256 elements and could acquire a 60 × 60 degree pyramidal volume in a single heartbeat. While this system displayed in RT only several cross-sectional images, it ultimately rendered 3D images.7–9 This sparse array matrix transducer was bulky, prevented good coupling with the ...