Do contrast agents affect ultrasound flow measurements?

Area of Science:

• Medical Imaging
• Vascular Ultrasound
• Diagnostic Technologies

Background:

• Iodine contrast agents in angiography pose patient risks.
• Duplex ultrasound offers a potential alternative to angiography.
• Current duplex ultrasound often requires confirmatory x-ray angiography, leading to complications.

Purpose of the Study:

• To investigate the impact of Doppler contrast agents on duplex ultrasound velocity measurements.
• To assess the accuracy of contrast-enhanced duplex ultrasound for detecting slow blood flow and intracerebral flow.
• To compare contrast-enhanced Doppler measurements with a high-resolution laser-Doppler anemometer reference.

Main Methods:

• Utilized color-coded Doppler ultrasonography with and without contrast agents.
• Employed pulsed, one-goal measurement techniques.
• Used a laser-Doppler anemometer (LDA) as a reference standard for velocity measurements.

Main Results:

• Doppler contrast agents improve detection of slow blood flow in stenotic vessels and intracerebral flow.
• Contrast agent amplification affects Doppler echo, altering measurements at both high and low flow rates.
• Precise flow rate recording can be challenging due to measurement alterations.

Conclusions:

• Low-risk Doppler contrast agents can enhance the safety and diagnostic capabilities of duplex ultrasound.
• Further research is needed to optimize measurement accuracy in the presence of contrast agents.
• Calibration against reference methods is crucial for reliable velocity quantification.