Related Experiment Video
Updated: Jul 29, 2026
A High-Throughput Image-Guided Stereotactic Neuronavigation and Focused Ultrasound System for Blood-Brain Barrier Opening in Rodents
Published on: July 16, 2020
The size distribution of the agitated saline microbubbles for contrast transcranial Doppler generated using standard
Zhengbin Pan1, Yiting Xiao1, Zhiyue Wang1
1Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, China.
Abstract:
Agitated saline microbubbles (MBs) are a common contrast agent for determining right-to-left shunt (RLS) by the contrast transcranial Doppler (c-TCD). The size of the generated bubbles is not standardized in clinical practice. MBs were generated using the recommended manual method by reciprocating motion through two syringes. The bubble size distributions (BSD) were measured using the microscopic shadow imaging technique. The results show that the diameter of MBs is mainly distributed between 10 and 100 μm, the mean bubble size is between 21 and 34 μm, the Sauter mean diameter (D32) is primarily between 50 and 300 μm, and the standard deviation (SD) is between 6 and 17 μm in 80 experiments. It provides a more accurate basis for the recommended manual method instability. The high variance values of the BSD indicate that the manual method has low stability and repeatability. The results of this study can be useful for further improvement of the reliability of c-TCD in detecting RLS. RESEARCH HIGHLIGHTS: This study provided the first detailed descriptions of the MBs size distribution in a flowing contrast agent by the microscopic shadow imaging technique. It reveals significant differences in the bubble size of manual foaming during repeated manipulations for each individual and between individuals.
Insights
Agitated saline microbubbles (MBs) used for right-to-left shunt (RLS) detection via contrast transcranial Doppler (c-TCD) show inconsistent sizes. This manual generation method lacks stability and repeatability, impacting diagnostic accuracy.
Area of Science:
- Medical Imaging
- Ultrasound Technology
- Fluid Dynamics
Background:
- Agitated saline microbubbles (MBs) are crucial contrast agents for diagnosing right-to-left shunt (RLS) using contrast transcranial Doppler (c-TCD).
- Current clinical practice lacks standardization in the size of MBs generated for c-TCD procedures.
- Inconsistent microbubble size can affect the reliability of RLS detection.
Purpose of the Study:
- To characterize the bubble size distributions (BSD) of agitated saline microbubbles generated by the manual method.
- To assess the stability and repeatability of the manual MB generation technique for c-TCD.
- To provide data for improving the reliability of c-TCD in RLS detection.
Main Methods:
- Microbubbles (MBs) were generated using the standard manual method involving reciprocating motion through two syringes.
- Bubble size distributions (BSD) were measured using the microscopic shadow imaging technique.
- Eighty experiments were conducted to analyze variations in MB size.
Main Results:
- MB diameters primarily ranged from 10 to 100 μm, with mean sizes between 21 and 34 μm.
- Sauter mean diameter (D32) was mainly between 50 and 300 μm, and standard deviation (SD) ranged from 6 to 17 μm.
- High variance in BSD indicated low stability and repeatability of the manual generation method.
Conclusions:
- The manual generation of microbubbles for c-TCD exhibits significant instability and poor repeatability.
- Detailed characterization of MB size distribution is essential for enhancing the diagnostic accuracy of c-TCD.
- Findings support the need for standardized protocols in microbubble preparation for reliable RLS detection.
