Tissue Doppler echocardiography Tissue Doppler echocardiography Tissue Doppler echocardiography (TDE) is a medical ultrasound technology, specifically a form of echocardiography that measures the velocity of the heart muscle (myocardium) through the phases of one or more heartbeats by the Doppler effect (frequency shift) of the reflected ultrasound. The technique is the same as for flow Doppler echocardiography measuring flow velocities. Tissue signals, however, have higher amplitude and lower velocities, and the signals are extracted by using different filter and gain settings. The terms tissue Doppler imaging (TDI) and tissue velocity imaging (TVI) are usually synonymous with TDE because echocardiography is the main use
Cooperative Human Tissue Network and procedures govern collection of biospecimens and their distribution to researchers: Cooperative Human Tissue Network The Collaborative Human Tissue Network (the CHTN) was established in 1987 by the National Cancer Institute in response to an increase in the demand for high quality biospecimens for cancer research. The purpose of the CHTN is to stimulate, for the good of the public, cooperative efforts to collect and distribute human biospecimens and to thereby facilitate research utilizing those specimens. These activities are expected to encourage basic and developmental studies in many areas of cancer research, including molecular biology, immunology and genetics. The CHTN