From the Guidelines
The primary distinction between a duplex ultrasound and a Doppler ultrasound lies in their capabilities, with duplex ultrasound combining traditional ultrasound imaging and Doppler technology to provide both anatomical and functional information, whereas Doppler ultrasound is solely focused on assessing blood flow characteristics. When considering the management of peripheral arterial diseases, as outlined in the 2024 ESC guidelines 1, duplex ultrasound emerges as a critical first step in vascular work-up for PAD screening and diagnosis. It allows for a dynamic, non-invasive examination that localizes vascular lesions, quantifies their extent and severity, and determines their hemodynamic relevance. The key advantages of duplex ultrasound include its ability to distinguish between atherosclerotic and non-atherosclerotic lesions, although its reliability is heavily dependent on the sonographer's expertise 1. Some of the benefits of using duplex ultrasound over Doppler ultrasound alone include:
- Comprehensive assessment of both blood vessel structure and blood flow
- Non-invasive and radiation-free, making it safe for repeated use
- Ability to detect stenosis with a sensitivity of 88% and specificity of 95% for >50% stenosis detection, as noted in the guidelines 1
- Utility in follow-up post-revascularization, in combination with ABI or TBI, to monitor patient progress and the effectiveness of interventions. Given the information provided in the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases 1, duplex ultrasound is the preferred method for vascular assessment due to its comprehensive nature and the detailed information it provides about both vessel anatomy and blood flow dynamics.
From the Research
Duplex Ultrasound and Doppler Difference
- A duplex ultrasound is a combination of two types of ultrasound technologies: Doppler ultrasound and conventional ultrasound 2.
- Doppler ultrasound is a type of ultrasound that uses the Doppler effect to measure the velocity of blood flow, while conventional ultrasound uses high-frequency sound waves to create images of internal structures.
- The main difference between a duplex ultrasound and a Doppler is that a duplex ultrasound combines both Doppler and conventional ultrasound to provide a more comprehensive view of blood flow and internal structures.
Key Features of Duplex Ultrasound
- Duplex ultrasound can provide high-resolution diameter and velocity information in real-time 3.
- It is a non-invasive technology with minimal risks or contraindications.
- Duplex ultrasound can be used to assess volumetric blood flow in various arteries, including the carotid and vertebral arteries.
- It is commonly used to diagnose and monitor vascular diseases, such as peripheral artery disease and deep vein thrombosis 4, 5.
Comparison with Other Imaging Modalities
- Duplex ultrasound has been compared to other imaging modalities, such as CT angiography, and has been found to be a reliable alternative for treatment planning of peripheral artery disease 4.
- However, the accuracy of duplex ultrasound can depend on the operator's skill and experience, as well as the quality of the equipment used 3.