[Background and purpose]Two-dimensional transesophageal echocardiography(2D
TEE) is a useful method for evaluating thoracic aortic atherosclerosis.
However, real time three-dimensional transesophageal echocardiography(3D
TEE) technique has been recently developed and is not widely used for
evaluating thoracic aortic atherosclerosis yet. The aim of this study is to
assess whether the real time 3D TEE method is useful for evaluating thoracic
aortic atherosclerosis or not.

[Methods]TEE was performed on 44 ischemic stroke patients(26 males, 18
females). We evaluated plaque thickness, mobile plaque and ulcer formation
using 2D and real time 3D methods. We measured the size of mobile lesion and
ulceration, and calculated the volume of mobile plaque and ulceration with
3D volume analysis(stacked contours method).

[Results]Mobile plaque was observed in 4 patients and ulcer formation in 3
patients. Plaque thickness over 4 mm was observed in 19 patients. It was
possible to measure the size of mobile lesion and ulcer using both 2D and 3D
TEE images. However, it was possible to calculate the volume of mobile
lesion and ulcer only from 3D TEE images.

[Conclusions]Real time 3D TEE method is useful to assess thoracic aortic
atherosclerosis, particularly the volume analysis of mobile plaque and
ulceration.