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
Loose connective tissue Loose connective tissue Loose connective tissue is a category of connective tissue which includes areolar tissue, reticular tissue, and adipose tissue. Loose connective tissue is the most common type of connective tissue in vertebrates. It holds organs in place and attaches epithelial tissue to other underlying tissues. For example, it forms telae, such as the tela submucosa and tela subserosa, which connect mucous and serous membranes to the muscular layer. It also surrounds the blood vessels and nerves. Cells called fibroblasts are widely dispersed in this tissue; they are irregular branching cells that secrete strong fibrous proteins and proteoglycans as