Contrast echocardiography for pulmonary blood volume quantification

Area of Science:

• Cardiovascular imaging
• Hemodynamics
• Medical ultrasound

Background:

• Pulmonary blood volume (PBV) quantification is crucial for diagnosing and monitoring circulatory conditions.
• Current transpulmonary indicator dilution techniques are invasive, requiring double catheterization.
• There is a need for less invasive methods to assess PBV.

Purpose of the Study:

• To present and validate a novel, minimally invasive ultrasound-based technique for blood volume quantification.
• To assess the accuracy of this new method compared to existing techniques.

Main Methods:

• A peripheral bolus of ultrasound contrast agent was injected and detected centrally using ultrasound transducers.
• Multiple indicator dilution curves (IDCs) were generated from echocardiographic views of cardiac cavities and central vessels.
• Blood volumes were calculated using contrast mean-transit-time differences derived from IDCs and cardiac output, with Local Density Random Walk and First Passage Time models applied.

Main Results:

• In vitro validation demonstrated highly accurate volume measurements across a range of flows.
• The volume estimate determination coefficient exceeded 0.999 for both applied models.
• Preliminary patient studies yielded promising results, indicating clinical potential.

Conclusions:

• The developed ultrasound technique offers a minimally invasive and accurate method for blood volume quantification.
• This approach has the potential to replace invasive methods for PBV assessment.
• Further clinical studies are warranted to confirm its utility in patient care.