The Size Distribution of the Agitated Saline Microbubbles for c-TCD
generated using Standard Manual Methods
Abstract
Agitated saline microbubbles (MBs) is 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. The microbubbles 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 10-100 µm, the mean bubble size is between
21-34 μm, the Sauter mean diameter (D 32) is mainly
between 50-300 μm, and the standard deviation (SD) is between 6-17 μm in
60 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 size distribution of
microbubbles 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.