Real-time cylindrical curvilinear 3-D ultrasound imaging
In patients that are obese or that exhibit signs of pulmonary disease, standard transthoracic scanning may yield poor quality cardiac images. For these conditions, two-dimensional transesophageal echocardiography (TEE) is established as an essential diagnostic tool. Current techniques in transesophageal scanning, though, are limited by incomplete visualization of cardiac structures in close proximity to the transducer. Thus, we propose a 2D curvilinear array for 3D transesophageal echocardiography in order to widen the field of view and increase visualization close to the transducer face. In this project, a 440 channel 5MHz two-dimensional array with a 12.6 mm aperture diameter on a flexible interconnect circuit has been molded to a 4mm radius of curvature. Using this transducer in conjunction with modifications to the beam former delay software and scan converter display software of the Volumetrics Medical Imaging 3D scanner, we obtained cylindrical real-time curvilinear volumetric scans of tissue phantoms including a field of view of greater than 120° in the curved, azimuth direction and 65° phased array sector scans in the elevation direction. These images were achieved using a stepped subaperture across the cylindrical curvilinear direction of the transducer face and phased array sector scanning in the non-curved plane.
