Two surfactant-based contrast agents, ST44 and ST68, were produced according to US Patent # 5,352,436 and filled with either air, C4F10 (perfluorobutane) or SF6 (sulfur hexaflouride). Ten rabbits received i.v. injections of each agent/gas combination with 5 repetitions of each dose (range: 0.005-0.13 mL/kg). A custom-made 10-MHz cuff transducer was placed around the surgically exposed distal aorta and audio Doppler signals were acquired in vivo. Quantitative in vivo dose responses were calculated off-line using spectral power analysis and compared to a theoretical model of microbubble dissolution and enhancement. For qualitative comparisons, 10 rabbits were imaged pre- and postcontrast administration (dose: 0.1 mL/kg) in gray-scale and colour. All agent/gas combinations produced marked Doppler enhancement with air bubbles enhancing least of all (p < 0.0001) and ST68-SF6 best of all (maximum: 27.6 +/- 2.04 dB; p < 0.012). There were no significant differences between other agent/gas combinations (0.30 < p < 0.70). Theoretical enhancement was within 1 order of magnitude of the experimental observations (i.e., deviations of up to 10 dB). The duration of contrast enhancement was 1-2 min for air-filled bubbles, 3-5 min for SF6-filled bubbles and more than 7 min for C4F10-filled bubbles. In conclusion, ST68-SF6 microbubbles produced most in vivo enhancement of the agent/gas combinations studied. Theory matched the measurements within an order of magnitude.
This research output has an Altmetric Attention Score of 6. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 11 July 2023.
All research outputs
#6,780,480
of 31,542,270 outputs
Outputs from Ultrasound in Medicine & Biology
#492
of 3,193 outputs
Outputs of similar age
#8,688
of 48,112 outputs
Outputs of similar age from Ultrasound in Medicine & Biology
#5
of 18 outputs
Altmetric has tracked 31,542,270 research outputs across all sources so far. This one has received more attention than most of these and is in the 74th percentile.
So far Altmetric has tracked 3,193 research outputs from this source. They receive a mean Attention Score of 4.6. This one has gotten more attention than average, scoring higher than 71% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 48,112 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 66% of its contemporaries.
We're also able to compare this research output to 18 others from the same source and published within six weeks on either side of this one. This one is in the 44th percentile – i.e., 44% of its contemporaries scored the same or lower than it.
