Optimizing an ultrasound contrast agent's stability using in vitro attenuation measurements.
OBJECTIVE
To evaluate the changes in the microbubble population of a currently available ultrasound contrast agent (USCA) through attenuation measurements to optimize its clinical use.


METHODS
The microbubble population from a galactose-based USCA (Levovist, Schering AG, Germany) was characterized in vitro using attenuation measurements. The effect of dose (0.1, 0.5, and 1 mL), concentrations (200, 300, and 400 mg mL(-1)) and time since reconstitution (2, 12, 22, and 32 minutes) was evaluated using two broadband pulses at different peak negative pressures (0.39 and 0.49 MPa) for a total of 72 injections.


RESULTS
Two minutes after reconstitution, a linear relationship was found between attenuation measurements and the amount of USCA (slope 0.92 dB x mg x cm(-1) ml(-1), R = 0.86). For a given dose and concentration, the microbubble stability was significantly reduced with the increase of the time since reconstitution, particularly for the lower concentrations.


CONCLUSIONS
The persistence and contrast effect of Levovist can be improved by using recommended minimum time since reconstitution and maximum concentration.
Correas
Jean-Michel
JM
Laboratoire d'Imagerie Paramétrique, University of Paris, France. jean-michel.correas@nck.ap-hop-paris.fr
Kurtisovski
Erol
E
Bridal
S Lori
SL
Amararene
Amar
A
Hélénon
Olivier
O
Berger
Geneviève
G
D003287:Contrast Media / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004355:Drug Stability; D004867:Equipment Design; D066298:In Vitro Techniques; D007267:Injections; D008863:Microspheres; D011134:Polysaccharides / Q000008:administration & dosage*; D018709:Statistics, Nonparametric; D014463:Ultrasonography
D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508