Arterial doppler lower limbs.pptx

Arterial doppler lower limbs

1. Dr. KAZIM ULLAH RESIDENT RADIOLOGY CMH ABBOTTABAD Arterial doppler lower limbs

2. SEQUENCE Introduction Anatomy Technique Pathologies Reporting

3. INTRODUCTION Ultrasonography can diagnose stenosis through the direct visualization of plaques and through the analysis of the Doppler waveforms in stenotic and post stenotic arteries. To perform Doppler ultrasonography of the lower extremity arteries, the operator should be familiar with the arterial anatomy of the lower extremities, basic scanning techniques, and the parameters used in color and pulsed-wave Doppler ultrasonography

4. anatomy

5. Ultrasound technique 5 MHz Linear Transducer(Range 3- 10 MHZ) The transducer is placed over an artery for transverse scanning, and then is rotated 90° for longitudinal scanning The artery should be scanned on a longitudinal plane as long as possible Optimize Gray Scale And Color Doppler Parameters Adjust Pulse Repetition Frequency(PRF) To Detect Hemodynamic Disturbances Perform Pulse Doppler In Regions Of Color Aliasing/ distubance

6. Ultrasound technique

7. Arteries scanned in doppler ultrasound of lower limbs Common femoral artery Profunda femoris artery Superficial femoral artery Popliteal artery Tibio -peroneal trunk Posterior tibial artery Peroneal artery Anterior tibial artery Dorsalis pedis artery

8. Ultrasound anatomy of the lower extremity arteries Arteries can be differentiated from veins on US by several characteristics. Arteries are round in transverse images, while veins are somewhat oval. Arteries are smaller than veins. Arteries have visible walls and sometimes have calcified plaques on the walls. When the vessels are compressed by the transducer, arteries are partially compressed, while veins are completely collapsed

9. Ultrasound anatomy of the lower extremity arteries

10. Ultrasound anatomy of the lower extremity arteries

11. Ultrasound anatomy of the lower extremity arteries

12. Ultrasound anatomy of the lower extremity arteries

13. Peripheral arterial disease Narrowing or blockage of the vessels that carry blood from heart to the legs RISK FACTORS Diabetes Smoking Advancing age Hypercholesterolemia Hypertension Obesity

14. Causes of lower limb arterial diseases Atherosclerosis Thrombosis/ embolism Aneurysm Intimal dissection Pseudo aneurysm AV fistula Arteritis Entrapment syndrome Cystic adventitial disease

15. Waveform shape Peak systolic velocity Spectral window Components to look for in stenosis

16. Doppler waveforms Doppler waveforms refer to the morphology of pulsatile blood flow velocity tracings on spectral Doppler ultrasound. Waveforms differ by the vascular bed (peripheral, cerebrovascular, and visceral circulations) and the presence of disease. Most authorities describe three types based on the number of phases of flow in each cardiac cycle

17. Triphasic flow Doppler spectrum of normal lower extremity arteries having three phases, due to crossing the zero flow baseline twice in each cardiac cycle systolic forward flow early diastolic flow reversal (below zero velocity baseline) late diastolic forward flow (slower than in systole)

18. Normal peripheral arterial waveform

19. Biphasic flow

20. Monophasic flow

21. Peak systolic velocity Peak systolic velocity (PSV) is an index measured in spectral Doppler ultrasound. On a Doppler waveform, the peak systolic velocity corresponds to each tall “peak” in the spectrum window.

22. Peak systolic velocity

23. Peak systolic velocity Peak systolic velocity (PSV) is an index measured in spectral Doppler ultrasound. On a Doppler waveform, the peak systolic velocity corresponds to each tall “peak” in the spectrum window.

24. Spectral window In normal straight vessels, blood flows are mostly in parallel and of constant velocities. Thus, Doppler spectral wave-forms appear concentrated and have no low velocity blood flow, thereby forming a so-called spectral window due to the absence of Doppler signal below the spectrum. When blood flow velocity is non-parallel flow, a wide range of blood flow velocities can be recorded simultaneously, resulting in spectral broadening of Doppler spectral waveforms. When low velocity turbulence arises in blood vessels, the turbulent signals will appear in the original spectral window, causing a disappearance or decrease in the spectral window, which is called spectral fill-in

25. Spectral window

26. Grading of arterial stenosis

27. Grading of arterial stenosis

28. Criteria for the classification of peripheral arterial stenosis 1-19% diameter reduction - Minimal disease 20-49% diameter reduction - Moderate disease 50-99% diameter reduction - Significant disease Occlusion

29. Mild spectral broadening>1-29 % Increase in peak systolic velocity (VR<1.5) Normal waveform. 1-19% Diameter reduction - Minimal Disease

30. Spectral broadening>30-99 % Increase in peak systolic velocity(VR 1.5-2) Reverse flow component present 20-49% Diameter reduction - Moderate Disease

31. Monophasic waveform Loss of reverse flow component (Mono-phasic flow) Marked spectral broadening 100% increase in systolic velocity(VR >2) Post-stenotic turbulence. 50-99% Diameter reduction. Significant Disease

32. Absence of flow in occlusion Proximal flow is high resistance Distal flow is low resistance with tardus pattern Collateral flow occlusion

33. Low velocity monophasic waveforms Lose triphasic character Tardus parvus appearance (prolong systolic acceleration and small systolic amplitude) Low resistance related to degree of ischemia Collateral flow

34. collaterals

35. Thrombosis or embolism

36. aneurysm

37. Intimal dissection

38. Report writing Arteries of lower limbs shows normal tri-phasic flow No atherosclerotic plaques are seen in major arteries of both lower limbs The blood flow velocities are with in normal range in all major arteries and their main branches in both lower limbs down to dorsalis pedis arteries in feet

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