Conventional three-dimensional (3D) echocardiography requires image visualization in a gray-scale format and limited value in assessing color Doppler flow signals We used a new technique for reconstructing color flow signals 3D color Doppler transesophageal echocardiography. The purpose of this study was to assess clinical feasibility of 3D reconstruction of color Doppler signals in patients with valvular regurgitation. We studied 3 patients with severe mitral regurgitation and 2 patients with moderate aortic regurgitation. The patients underwent transesophageal echocardiography and the 3D data sets were acquired using a rotating probe at 2 increments with ECG gating. The digital data sets for two-dimensional echocardiographic and Doppler flow signals were stored separately on magneto-optical disks and 3D reconstruction was performed. We examined (1) the extent of the regurgitant jet, (2) direction of the regurgitant jet. (3) shape of acceleration flow and (4) shape of regurgitant orifice.
3D color Doppler transesophageal echocardiography allows direct visualization of the extent of regurgitant jets. regurgitant orifice and complex shape of acceleration flow in the optimal plane. At present, this system does not allow to display the turbulent flow signals of the regurgitant jets. Observation of the extent of regurgitant jet signals at near transesophageal transducer field was limited in severe mitral regurgitation. Continued development of 3D color Doppler transesophageal echocardiography, however, should progressively ameliorate these limitations. In conclusion, 3D color Doppler transesophageal echocardiography revealed new images of extent of the complex regurgitant jets, acceleration flow geometry as well as the anatomical shape of regurgitant orifice.

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Inspired by the difference is ultrasound image information between fundamental tomography (sending and receiving frequency 3.5 MHz), tissue harmonic method (sending frequency 1.75 MHz/receiving frequency 3.5 MHz), and tissue harmonic method+B-color method (sepia tone) in echocardiography, conditions of image acquisition for minimizing operator variability in ultrasound image acquisition were investigated. Furthermore, differences between fundamental tomography and fundamental tomography+B-color method were also investigated.
Fundamental tomography+tissue harmonic method and fundamental tomography+B-color method were found to be useful in both the group with normal left ventricular motion and group with abnormal left ventricular motion in minimizing operator variability in ultrasound image acquisition. The results of this study suggested that the addition of the B-color method was useful particularly in the group with abnormal left ventricular wall motion.
It seems necessary to improve the accuracy in ultrasound image acquisition through judicious combination of fundamental tomography with the tissue harmonic method or the B-color method to obtain ultrasound image information with the lowest operator variability possible.

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