Effects of ultrasound and ultrasound contrast agent on vascular tissue.
BACKGROUND
Ultrasound (US) imaging can be enhanced using gas-filled microbubble contrast agents. Strong echo signals are induced at the tissue-gas interface following microbubble collapse. Applications include assessment of ventricular function and virtual histology.


OBJECTIVE
While ultrasound and US contrast agents are widely used, their impact on the physiological response of vascular tissue to vasoactive agents has not been investigated in detail.


RESULTS
In the present study, rat dorsal aortas were treated with US via a clinical imaging transducer in the presence or absence of the US contrast agent, Optison. Aortas treated with both US and Optison were unable to contract in response to phenylephrine or to relax in the presence of acetylcholine. Histology of the arteries was unremarkable. When the treated aortas were stained for endothelial markers, a distinct loss of endothelium was observed. Importantly, terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) staining of treated aortas demonstrated incipient apoptosis in the endothelium.


CONCLUSIONS
Taken together, these ex vivo results suggest that the combination of US and Optison may alter arterial integrity and promote vascular injury; however, the in vivo interaction of Optison and ultrasound remains an open question.
Food and Drug Administration, Center for Devices and Radiological Health (CDRH), 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA. steven.wood@fda.hhs.gov
Steven C
SC
Wood
Sible
S
Antony
Ronald P
RP
Brown
Jin
J
Chen
Edward A
EA
Gordon
Victoria M
VM
Hitchins
Qin
Q
Zhang
Yunbo
Y
Liu
Subha
S
Maruvada
Gerald R
GR
Harris
D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology; D017209:Apoptosis; D003287:Contrast Media / Q000494:pharmacology*; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D018617:Ultrasonography, Doppler, Pulsed; D014661:Vasoconstriction / Q000187:drug effects*
D003287:Contrast Media