This is the first book to present an overview of the exciting new cardiac imaging technique of
tissue Doppler echocardiography (TDE). In order to understand the background of this technique
it is necessary to compare the physical properties of blood which reflects ultrasound poorly
but moves with high velocity (up to 150 cm s) with those of the myocar dium which reflects
ultrasound strongly but moves with low velocity (less than 10 cm s). In tissue Doppler imaging
existing Doppler technology has been modified to bypass the high-pass filter and enhance
calculation of low velocities thus enabling selective visualization of the myocardium rather
than of the blood. Because the color Doppler tissue images are super imposed on the
conventional two-dimensional ultrasound images this technique is known as TDE. Following a
brief introduction the history of ultrasound and Doppler imaging is presented. It is now about
150 years since the death of Christian Doppler who described the Doppler effect and more than
100 years since Pierre Curie discovered the piezoelectric effects of crystals. TDE was
developed by Nobuo Yamazaki and Yoshitaka Mine at the Medi cal Engineering Laboratory Toshiba
Corporation Tochigi Japan. En gineers involved in the development of the technique have
provided important technical information which the reader will find an invaluable background
to potential applications ofTDE.
