Difference Between Doppler and Duplex (With Table)

Human life is full of diseases, running to the hospitals and getting cured. Meanwhile, technologies like ultrasound and ultrasonography are a boon to mankind and play a very important role. In ancient times or the early stages of the development of ultrasound technology, Doppler was used. It was in use because of its ability to measure the pace of blood flow through the vessels.

With the advancement of technology, Duplex was developed, which included all the works of Doppler as well. However, they are almost similar but have certain differences between them as well.

Doppler vs Duplex

The difference between Doppler and Duplex is that Doppler is a type of medical non-invasive study of ultrasonography in which the blood vessels and heart are studied. It includes high-frequency waves with ultrasound. On the other hand, Duplex is a type of non-invasive medical ultrasonography, combining Doppler ultrasonography and traditional ultrasonography. Doppler ultrasonography is the ancient approach, whereas Duplex ultrasonography is the modern approach.

In Doppler ultrasonography, a coloured image of flowing blood is detected. This ultrasonography is known for providing information on the blood flow present in the studied vessels and their speed, direction and turbulence as well. This technology is an independent study. It provides less and limited data on various sources. Doppler ultrasonography has been in use since the emergence of ultrasound technology.

Duplex ultrasonography provides a coloured image and detects the flowing blood. However, it also provides 2-D greyscale images of ultrasound of the tissues. This technology is known for presenting information on the presence of flow of blood on specific vessels with in the body with its speed, turbulence, direction, the image of the tissues surrounding them. This ultrasonography technology has its emergence from Doppler ultrasonography.

Comparison Table Between Doppler and Duplex

Parameters of ComparisonDopplerDuplex
StudyIt studies the blood vessels, heart and includes high-frequency waves with ultrasound.It is a combination of Doppler ultrasonography and traditional ultrasonography.
PictureIt detects coloured picture of the blood flow.The detection of coloured pictures of blood flow also includes 2-D greyscale ultrasound images of the body tissues.
InformationBlood flow, speed, direction, turbulence.Blood flow in vessels, speed, turbulence, direction, pictures of the tissues surrounding the vessels.
KindIndependent study.It is a part of Doppler ultrasonography.
DataProvides less and limited data.It covers a bigger area of study and presents more data.
EvolutionThis technology has been in use since the emergence of the early stages of ultrasound technology.This technology has been in use as a part of modern ultrasound technologies.

What is Doppler?

Doppler ultrasonography is known for emitting waves of ultrasonic range or ultrasound waves. Then the work of the receiver is to pick up the echoes. Later these echoes are translated into sounds. Several details are drawn out from the sounds, such as heart rate, velocity, etc. This is done by studying the pattern and pitch of the sounds in detail.

At present, Doppler ultrasonography machines are available and are used in the measurement of the heart rate of the foetus. Doppler ultrasonography uses the Doppler Effect, which is present in physics. Its work is to show an image of the circulation of blood in the veins and arteries. According to Doppler, a great physician, the doppler effect is the linkage between transmitted sounds’ wave frequency from a mobile object and the observer.

In the case of Doppler ultrasonography, erythrocytes are the mobile elements in the blood. This technology is used in the diagnosis of vascular surgery and access several diseases related to blood vessels. These diseases include embolism, varicose veins, arterial thrombosis, venous thrombosis, aneurysms, thrombophlebitis and many more.

What is Duplex?

Duplex ultrasonography is a part of the modern-day approach of ultrasound scanning machines. The ultrasonic waves received help in presenting the anatomy of an organ that is involved in greyscale. It covers a larger area of study and provides a large amount of data. This technology is a part of modern ultrasound technology and recently developed. In Duplex ultrasonography, the ultrasonic waves pass through the body fluids and tissues. Later it bounces back and creates echoes.

From the echoes received to the ultrasound machine, visualisation is possible, that too, without any invasiveness. The ultrasound machines available in the modern world have the potential to show two distinct images simultaneously. It provides both greyscale and colour visualisation of the flowing blood and body tissues. However, it also uses the Doppler effect.

The Duplex ultrasonography machines give the operator a chance to select a specific area on the image and detect the blood flow of that particular area. It is also helpful in the diagnosis and detection of blood vessel blockages, vessel width, etc. This technology is used in the diagnosis of blood clots, abdominal aneurysm, arterial occlusion, varicose veins, venous insufficiency, carotid occlusive disease.

Main Differences Between Doppler and Duplex

  1. Doppler is a kind of ultrasonography which is a medical non-invasive study of blood vessels and heart, includes high-frequency waves with ultrasound. On the other hand, Duplex is a type of ultrasonography that is also a medical non-invasive study combining Doppler ultrasonography and traditional ultrasonography.
  2. In Doppler ultrasonography, a colour picture of the blood flow is detected. However, Duplex ultrasonography also provides a colour picture of blood flow detection, but it also includes 2-D images of greyscale ultrasound of the tissues.
  3. Doppler ultrasonography is known for providing information on the blood flow present in the vessels studied and the speed, direction and turbulence as well. However, Duplex ultrasonography is known for giving data on the presence of flow of blood on specific vessels with its speed, turbulence, direction, the image of the tissues surrounding the vessels.
  4. Doppler ultrasonography is an independent study. However, Duplex ultrasonography is a part of Doppler ultrasonography.
  5. Doppler ultrasonography provides less and limited data. Whereas, Duplex ultrasonography covers more area of study and provides more data.
  6. Doppler ultrasonography has been in use since the early stages of ultrasound technology. Whereas, Duplex ultrasonography has been in use as a part of modern ultrasound stages of technology.

Conclusion

Both the ultrasonography technologies, Doppler and Duplex ultrasonography, are used in examining the rate and pace of blood flow in the major veins and arteries in human legs and arms. Duplex ultrasonography is used for visualisation purpose. Doppler ultrasonography is used for the hearing of the audio purpose. This technology provides a way to listen to the sound of the blood flow.

These are the alternative methods to venography and arteriography. However, these technologies help in the detection and diagnosis of abnormalities in a vein or artery. Almost everything is the same, except Doppler is an ancient approach or technology, and Duplex is a recent development in technology.

References

  1. https://pubs.rsna.org/doi/abs/10.1148/radiology.198.2.8596864
  2. https://pubs.rsna.org/doi/abs/10.1148/radiology.173.3.2682776
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