Tissue Doppler echocardiography
![Spectral tissue velocity curves from the mitral annulus at the septal (left) and lateral (right) points. The curves show multiple heartbeats.](/Images/godic/202502/16/PwTDI3729.jpg")
![Single spectral tissue velocity curve from the mitral annulus. The curve shows velocities towards the probe (positive velocity) in systole, and away from the probe (negative velocities) in diastole. The most useful measures are the peak velocities, in systole S' and in early diastole (e') and late diastole during atrial contraction (a').](/Images/godic/202502/16/PwTVI3729.jpg")
![relation between mitral flow and mitral annulus velocity. Left: Normal person with good diastolic function; high E and e', normal E/e'. Middle, patient with diastolic dysfunction without increased filling pressure; low E and e', normal E/e' ratio. Left, patient with diastolic dysfunction and increased filling pressure; high E, low e' and high E/e'. Note also that the S' is reduced in proportion to the e'](/Images/godic/202502/16/Diastolic_function3729.png")
![Age dependent normal values for S', e' and a'.](/Images/godic/202502/16/Velocities_from_HUNT_copy3729.jpg")
Tissue Doppler echocardiography (Also called Tissue Doppler Imaging - TDI or Tissue Velocity Imaging - TVI) is a Medical ultrasound technology mainly used in Echocardiography that measures the velocity of the heart muscle or 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 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. Like Doppler flow, Tissue Doppler can be acquired both by spectral analysis (Spectral density estimation) as pulsed Doppler and by the Autocorrelation technique as colour Tissue Doppler (Duplex ultrasonography). While pulsed Doppler only acquires the velocity at one point at a time, colour Doppler can acquire simultaneous pixel velocity values across the whole imaging field. Pulsed Doppler on the other hand, is more robust against noise, as peak values are measured on top of the spectrum, and are unaffected of the presence of clutter (stationary reverberation noise).