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Tissue Doppler Imaging Scott A Wright, M.D Overview Tissue Doppler vs flow Doppler Types of tissue Doppler Myocardial wall motion Myocardial velocity gradient Assessing regional systolic function Dobutamine stress testing Diastolic dysfunction Real time tissue Doppler imaging study Conventional Flow Doppler Measures blood flow velocities in cardiac chambers and great vessels High velocity flow Low amplitude signals High pass filters eliminate the low velocity high amplitude signals of the myocardial walls Tissue Doppler Measures the velocity of myocardial wall motion Low velocity High amplitude to 20 cm/s 10 times slower than velocity of blood flow Approximately 40 decibels higher than blood flow Low pass filters eliminate high velocity signals of blood flow Int J of Card Imaging 2001;17::89-98 Tissue Doppler TDI uses Doppler shift data from the myocardium to obtain qualitative and quantitative information on myocardial wall motion Tissue Doppler imaging Color TDI (2D) Color M-mode Pulse wave tissue Doppler Displays myocardial velocity over time from a sample volume Heart 2000;84(suppl II):ii11-18 Pulsed Wave Tissue Doppler Small sample volume Sample volume placed within the myocardial wall J Am Soc Echo 2001;14:1143-52 Tissue Doppler Imaging Standard color coding Myocardial motion away from transducer is blue Myocardial motion toward transducer is red Displayed as 2D Doppler image or color Doppler Mmode Echo Manual; J.Oh Tissue Doppler Due to low velocities being measured, aliasing never occurs Each color represents a range of velocities and direction Toward transducer Low velocity : red Intermediate velocity : orange High velocity : yellow Away from transducer Low velocity : blue Intermediate velocity : turquoise High velocity : green Velocity below threshold : gray Int J of Card Imaging1998;14:241-50 Advantages and Limitations of Color Advantages Spatial orientation of myocardial velocities can be superimposed on 2D image Myocardial velocities displayed similar to conventional color flow Representation of mean myocardial velocity Limitations Poor temporal resolution caused by longer processing times Typically requires off line analysis for quantification of myocardial velocity color maps J Am Soc Echo 2001;14:1143-52 Advantages and Limitations of Pulsed Wave Advantages Real time velocity interrogation with improved temporal resolution Peak velocity rather than mean velocity No off line analysis Instantaneous temporal display Assessment of regional function Limitations Only regional quantification of velocities reduces spatial resolution Sampling not localized to endo or epicardium Beam alignment difficult No correction for normal cardiac translation and rotation during sampling J Am Soc Echo 2001;14:1143-52 Diastolic Dysfunction : Standard Doppler Evaluation Impaired relaxation Psuedonormal Restrictive Echo Manual Diastolic Dysfunction : Standard Doppler Evaluation Normal Impaired Psuedonormal Restrictive Relaxation Filling DT 220 ms 150 - 200 ms < 150 IVRT 100 ms 60 - 100 ms < 60 E/A 1–2 2 Adur Mitral>PV Mitral> PVd PVs >> PVd PVs < PVd PVs cm/s J Am Coll Cardiol 1998;32:865-75 Diastolic Dysfunction : Tissue Doppler J Am Coll Cardiol 1998;32:865-75 Diastolic Dysfunction Normal Impaired Psuedonormal Restrictive Relaxation Filling DT 220 ms 150-200 ms PVd PVs >> PVd PVs < PVd PVs