Real-time two-dimensional and three-dimensional echocardiographic imaging of the thoracic spinal cord: a possible new window into the central neuraxis.

Transesophageal echocardiography of the spine has been difficult to perform, and high-quality images have been difficult to obtain with earlier available technology. New capabilities in hardware and software reconstruction may allow more reliable clinical data to be obtained. We describe an initial successful attempt to image the adult spinal canal, its contents, and in situ instrumentation. This report is a retrospective review of two patients in whom transesophageal echocardiography (TEE) was used to image the thoracic spine. The thoracic spine was identified and imaged with real-time 2-D and 3-D technology with location of the thoracic aorta and slight insertion and withdrawal of the TEE probe until the intervertebral discs alignment was optimized. Images of the spinal cord anatomy and its vascular supply, as well as indwelling epidural catheters were easily identified. 2-D and 3-D imaging was performed and images were recorded in digital imaging and communications in medicine format. 3-D reconstruction of images was possible with instantaneous 3-D imaging from multiple 2-D electrocardiogram-gated image acquisitions using the Phillips TEE IE-33 imaging platform. The central neuraxial cavity, including the spinal cord and the spinal nerve roots, was easily visualized, and motion of the cord was seen in a phasic pattern (with respiratory variation); cerebrospinal fluid surrounding the spinal cord was documented. The epidural space and local anesthetic drug administration through the epidural catheter were visualized, with the epidural catheter seen lying adjacent to the epidural tissue as a bright hyperechoic line. Pulsed-wave Doppler determined a biphasic pattern of blood flow in the anterior spinal artery through pulse mapping of the anatomic area. New, advanced imaging hardware and software generate clinically useful imaging of the thoracic spine in 2-D and 3-D using TEE. We believe this technology holds promise for future diagnostic and therapeutic interventions in the operating room that were previously unavailable.