Coulter counter size distribution measurements for (a) Definity, (b) MicroMarker, (c) echogenic liposomes (ELIP), (d) enhanced ELIP and (e) recombinant tissue plasminogen activator (rt-PA)-loaded ELIP. Mean number density (histogram, shaded) and volume-weighted size distribution (solid line) are plotted versus particle diameter (note logarithmic scale on the abscissa). The dotted lines represent one standard deviation of the volume-weighted size distribution.
Dilution ratios are given in Table 2. Data are truncated at a diameter of 10 μm for clarity.