Basic concepts in Doppler ultrasound. The origin of the Doppler signal. What basic vascular Doppler signals look like and what these mean.

1. Doppler 101
(The Basics)
Durr-e-Sabih
MBBS. MSc.FRCP.FANMB
Multan Ultrasound Service

2. The Doppler effect!!!

9. The Doppler effect

10. https://en.wikipedia.org/wiki/Doppler_effect

11. The Doppler Equation
fD= fT-fR =
c
2 fT v cos

12. The Doppler Equation
fT= Transmitted frequency v= blood flow velocity
fD= Doppler shift c= speed of sound
fR= Received frequency
cos  = angle between flow direction and
ultrasound beam….cos 90 =0, cos 0 =1
fD= fT-fR =
c
2 fT v cos

13. 
fR
fT
v

14. How is the information displayed
Colour
Spectrum

15. What is the information
(Colour)
o Is there flow in the mass (solid/cystic)?
o Is the tubular structure vascular?
o Is the vessel an artery or vein?
o Is the flow laminar or chaotic?
o Is the flow towards or away from the probe?
o Does the flow respond to maneuvers
(Valsalva, distal augmentation etc)

18. Is this tube a vessel?

19. Is this tube a vessel?

20. What is the information
(Spectra)
o Is the flow towards or away from the probe?
o Throughout or in part of the cycle
o What is the velocity of the flow?
o Calculate the volume
o What is the character of flow?
o Laminar, disturbed, turbulent, dampened,
refluxing,
o Normal or altered upstream and downstream
vascular physiology

21. Display Schemes
Towards
the probe
Away
from the
probe
No flow
No flow
Flow
Colour Flow Image Power Doppler
velocity

22. Very High Velocity
Aliasing

23. Angle dependence

24. Angle dependence
www. Centrus.com.br/DiplomatFMF/doppler

25. The Components of the Spectrum

26. Display Schemes
Towards
the probe
Away
from the
probe
No flow
time

27. Display Schemes
Towards
the probe
Away
from the
probe
No flow
time
Systole
Diastole
Velocity
Systole

28. Display Schemes
Towards
the probe
Away
from the
probe
No flow
time
Z axis
Brightness
Population
Window

29. Velocity/
Frequency
Direction
Time
The number of cells at
this velocity
The Doppler Spectrum

30. The Window
Velocity

31. The Window
Velocity

32. The Spectrum
Inflow Outflow
Rigid pipe

33. Inflow Outflow
Compliant Reservoir
The Spectrum

34. Inflow Outflow
Compliant Reservoir
The Spectrum
Resistance

35. Distal resistance will change the
shape of the waveform
High Resistance Low Resistance

36. Low resistance, high resistance
areas
Low resistance flow is met with in visceral flows
Specially those viscera that have a constant and high
perfusion states. The brain is the most striking example.
Muscles at rest usually give high resistance patterns
But when exercised convert to low resistance.
Obstruction increases resistance, and dilatation of the
Distal vascular bed reduces it.

37. Normal ICA/ECA Flow

38. 3rd trim fetus Renal art

41. Systolic acceleration time

42. Oversimplification
o Proximal resistance will change proximal
part of the spectrum (acceleration time)
o Resistance at site of examination will
change peak of systole
o Distal resistance will change distal part of
the spectrum, diastole

43. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Look at the systolic acceleration time
o Dicrotic notch
o End of systole
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

44. Analyse
the
spectrum

45. Analyse
the
spectrum
Peak Systolic Velocity
Acceleration Time
Dicrotic notching
End diastolic
flow
or velocity
Spectral widening
Clear Window

46. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Dicrotic notch
o End of systole
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

47. Artery or
vein
o Directions usually opposite
o Venous walls undulate, arterial don’t
o Venous walls thinner
o Veins compressible
o Venous flow constant
or undulant
o Arterial flow pulsatile
o Venous flow affected
by Pressure, Valsalva

48. Artery or
vein
A
B
C
D

49. Artery or
vein

50. Artery
Resistance?

51. Artery or
vein

52. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Systolic acceleration time
o Dicrotic notch
o End of systole
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

53. Distal resistance will change the
shape of the waveform
High Resistance Low Resistance

54. Look at the diastole

55. Low resistance flow

56. High resistance flow
Brachial art
Femoral artery
Facial artery

57. o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Dicrotic notch
o End of systole
o Systolic acceleration time
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio
Analyzing the spectrum

58. Systolic acceleration
time

59. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Dicrotic notch
o End of systole
o Systolic acceleration time
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

60. Artery
Dicrotic notch

61. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Dicrotic notch
o End of systole
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

62. Velocity
© Chaitaniya Puranik, Indore

63. Velocity
© Chaitaniya Puranik, Indore
Angles of utmost importance
256cm/sec

64. Analyzing the spectrum
o Artery or vein
o Colour
o Spectrum
o Low or high resistance
o Look at the diastolic flow
o Dicrotic notch
o End of systole
o Velocity
o Systolic, diastolic velocities
o Indices
o RI, PI, SD ratio

65. Indices
https://sonoworld.com/Client/Fetus/html/doppler/capitulos-html/chapter_01.htm

66. Birthplace of physicist
Christian Doppler
Discoverer of the
astrophysical principle
named after him.
Born November 29th
1803, died March 17th
1853
On the occasion of his
100th birthday
The society for
Salzburgian Regional
Studies

67. Thank You