Microbubble Contrast Agents Improve Detection of Active Hemorrhage.

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Trauma Care

Background:

• Assessing trauma-induced hemorrhage is challenging in pre-hospital settings.
• The Focused Assessment with Sonography of Trauma (FAST) exam is limited in detecting ongoing blood loss.
• Current methods struggle to identify injuries of increasing severity.

Purpose of the Study:

• To enhance the detection of active bleeding in trauma patients using ultrasound contrast agents (UCAs).
• To develop novel flow phantom and contrast-sensitive processing techniques for characterizing internal bleeding.
• To improve the practical detection of hemorrhage in pre-hospital environments.

Main Methods:

• Utilized UCAs with a custom flow phantom and contrast-sensitive processing.
• Evaluated hemorrhage visualization through generalized contrast-to-noise ratio (CNR) measurements.
• Assessed detection probability using receiver operating characteristic (ROC) curves at various flow rates.
• Applied nonlinear processing (NLP) pipelines for spatial and temporal analysis.
• Compared Doppler signal enhancement with and without UCAs.

Main Results:

• UCAs significantly enhanced hemorrhage visualization, increasing CNR by a mean of 17% compared to contrast-free methods.
• The area under the ROC curve improved from 0.72 to 0.99 at a flow rate of 40 ml/min with UCAs.
• Novel processing techniques effectively localized bleeding sites.
• UCAs improved Doppler signal detection compared to conventional ultrasound.

Conclusions:

• Specialized nonlinear processing (NLP) pipelines combined with UCAs offer a substantial improvement in detecting slower hemorrhages.
• This approach holds potential for increasing survival rates in trauma-induced injuries in pre-hospital settings.
• UCAs represent a promising advancement for critical care ultrasound in emergency medicine.