Acoustic fingerprints of dye-labeled protein submicrosphere photoacoustic contrast agents.
Dye-labeled protein microspheres, submicron in size and capable of producing thermoelastically generated ultrasound in response to laser stimulation, are presented as contrast agents for photoacoustic imaging. Incident laser energy absorbed by fluorescein isothiocyanate (FITC)-labeled elastin submicrospheres results in thermoelastically generated sound production. Plotted A-line graphs reveal a distinctive morphology and a greater than two orders of magnitude increase in signal amplitude subsequent to converting FITC elastin into submicrospheres (despite a four orders of magnitude decrease in concentration). Evidence of nonlinearity and enhancement of ultrasound backscatter indicate a potential use in contrast-enhanced harmonic imaging. Photoacoustic and ultrasound imaging of FITC-elastin submicrospheres in a water-filled phantom vessel shows enhanced contrast at low concentration and clear delineation of the phantom vessel wall.
McDonald
Michael A
MA
National Institute of Standards and Technology, Chemical Science and Technology Laboratory, 100 Bureau Drive, Stop 8313, Gaithersburg, Maryland 20899-8313, USA. michael.a.mcdonald@nist.gov
Jankovic
Ladislav
L
Shahzad
Khalid
K
Burcher
Michael
M
Li
King C P
KC
D004396:Coloring Agents / Q000737:chemistry*; D003287:Contrast Media / Q000737:chemistry*; D004867:Equipment Design; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D008863:Microspheres; D055095:Optics and Photonics / Q000379:methods*; D010316:Particle Size; D019047:Phantoms, Imaging; D011506:Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D014463:Ultrasonography / Q000379:methods*; D014867:Water / Q000737:chemistry
D004396:Coloring Agents; D003287:Contrast Media; D011506:Proteins; D014867:Water; D016650:Fluorescein-5-isothiocyanate