Doppler Basic & Hemodynamic Calculations

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1 Doppler Basic & Hemodynamic Calculations August 19, 2017 Smonporn Boonyaratavej MD Division of Cardiology, Department of Medicine Chulalongkorn University Cardiac Center, King Chulalongkorn Memorial Hospital

2 3-D Echo 2

3 Doppler measures blood flow velocities in the heart and the great vessels, based on the Doppler effect 3

4 Doppler Effects 4

5 5

r > f t Target moving away from transducer T R f t f r

6 Basic ECHO Doppler Shift Target stationary T f t f t = f r R f r Target moving toward transducer T R f r f t f r > f t Target moving away from transducer T R f t f r f r < f t Doppler shift or frequency (f d ) = f r -f t 6

7 Doppler Shift If = 0, cos = m/sec 7

8 A Comparison of Two-Dimensional Echo and Doppler 2D-Echo Doppler Ultrasound target Tissue Blood Goal of diagnosis Anatomy Physiology Type of information Structural Functional Optimal alignment between beam and target Perpendicular Parallel Preferred transducer frequency High Low 8

9 Why velocity? 9

10 Bernoulli Equation Daniel Bernoulli 8 February March 1782 Swiss mathematician and physicist 10

11 Why do we want to know the velocity? V1 V2 Simplified Bernoulli Equation Pressure gradient = 4 (V V 12 ) Estimation Pressure gradient = 4V 2 11

12 Doppler shift = 2 f t v cos θ c Adapted from ECHOSAP 12

13 Rule of 20 degree 13

14 Doppler Pulsed-wave (PW) Doppler Continuous wave (CW) Doppler Color-flow (CF) Doppler 14

15 Pulsed- vs Continuous-wave Doppler Pulsed-wave Continuous-wave Measures specific blood flow Measures flow along the axis Maximum measurable vel < 2 m/s Maximum measurable vel 9 m/s Performed by Duplex transducer Performed by Duplex and nonimaging transducer Low vel at specific site Peak vel across orifice Clinical applications Clinical applications LVOT velocity and TVI Peak velocity and TVI Volume measurement Valvular pressure gradient Diastolic filling parameters Pressure half-time Mitral inflow velocity Pulmonary pressure Oh JK. Echo Manual 15

16 Doppler Velocities Display 16

17 Nonimaging CW Doppler Transducer 17

18 Doppler Display Audio Output High pitched sounds Large Doppler shifts presence of high velocity flow Low pitched sounds lesser Doppler shifts low velocity flow Flow direction information stereophonic audio output 18

19 PRF Adapted from ECHOSAP 19

20 Sample Volume 20

21 21

22 Normal Spectral Doppler LV inflow & RV inflow 22

23 23

24 Normal Spectral Doppler LV outflow & RV outflow 24

25 Normal Spectral Doppler Pulmonary vein 25

26 Superior Vena Cava Flow Measurement Techniques 26

27 Maximum frequency determined = 1/2 of the PRF (Nyquist frequency) Adapted from ECHOSAP 27

28 High PRF Doppler 28

29 Adapted from ECHOSAP 29

30 30

31 AV Continuous-wave Doppler Pressure Gradient 31

32 32

33 Doppler Control Panel 33

34 Doppler Gain "mirroring" or "crosstalk" 34

35 35

36 Greyscale 36

37 Wall Filter 37

38 38

39 Scale & Baseline Control 39

40 Pulsed Sample Depth & Size Deeper positioning of the sample volume > an automatic decrease in the Nyquist limit. Most users of pulsed Doppler will leave this gate in a midposition for routine scanning decrease or increase the size of the gate depending on the clinical situation 40

41 Color Flow Doppler 41

42 Color Doppler Imaging Utilizes multigated Pulse wave Doppler to estimate mean blood flow velocity Direction of blood flow is displayed using the traditional `BART colour scheme where flow away from the probe appears blue (BA) and flow towards the probe appears red (RT). There are 2 colour maps commonly encountered on echo machines: 42

43 Color Flow Doppler 43

Forward Reverse slow slow fast Flow velocity

44 Color Flow Imaging Turbulence Red to Yellow fast Red Yellow Magenta Blue Blue Green Flow direction Forward Reverse slow slow fast Flow velocity Turbulence Blue to Cyan Omnoto & Kasai Echocardiography

45 Color Doppler Velocity Map - 45

46 Color Doppler Variance Mode Laminar flow is blue or red; turbulent flow is yellow or green 46

47 47

48 48

49 Color Flow Doppler Color Aliasing

50 Color Flow Doppler Mitral Regurgitation

51 Mitral regurgitation Direction of Color Flow Jet Eccentric Central 51

52 Colour Doppler Images Ensure colour box covers the entire area of interest, Set the Nyquist limit scale appropriate to the structure of interest. Valvular and arterial structures is cm/sec. Slower velocity venous structures and the assessment of the interatrial septum is cm/sec 52

53 53

Hemodynamics assessment Mean RAP (CVP) Pulmonary artery (PA) pressure PA systolic pressure PA diastolic pressure Left atrial pressure (LAP) Left ventricular

54 Hemodynamics assessment Mean RAP (CVP) Pulmonary artery (PA) pressure PA systolic pressure PA diastolic pressure Left atrial pressure (LAP) Left ventricular enddiastolic pressure (LVEDP) Stroke volume (SV) and cardiac output (CO) Quantitation of Valve regurgitation Shunt volume Ventricular function Systolic Diastolic 54

55 55

56 Time - velocity Integral (TVI) 56

57 Pulmonary Artery Pressure TR peak velocity = RV systolic pressure - RA pressure RV systolic pressure =TR peak velocity + RA pressure 57

58 Pulmonary Artery Pressure TR peak velocity = RV systolic pressure - RA pressure RV systolic pressure =TR peak velocity + RA pressure PA systolic pressure 58

59 Pulmonary Artery Pressure TR peak velocity = RV systolic pressure - RA pressure RV systolic pressure =TR peak velocity + RA pressure IVC inspiratory collapse >50% RA pressure = 10 mmhg <50% RA pressure = mmhg 59

60 RA Pressure Approximation by 2-D Examination of the IVC 60

61 RV Systolic Pressure RVSP = 55 mmhg + 5 mmhg 61 Cardiol Clin 1990;8:277-87

62 PA Diastolic Pressure PA end-diastolic pressure = 4 x (PR end-diastolic velocity) 2 + RAP 62

63 Thank you for your kind attention 63

Hemodynamic Assessment. Assessment of Systolic Function Doppler Hemodynamics

Hemodynamic Assessment. Assessment of Systolic Function Doppler Hemodynamics Hemodynamic Assessment Matt M. Umland, RDCS, FASE Aurora Medical Group Milwaukee, WI Assessment of Systolic Function Doppler Hemodynamics Stroke Volume Cardiac Output Cardiac Index Tei Index/Index of myocardial