Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging

Shengtao Lin, Anant Shah, Javier Hernández-Gil, Antonio Stanziola, Bethany I. Harriss, Terry O. Matsunaga, Nicholas Long, Jeffrey Bamber, Meng Xing Tang

Research output: Contribution to journalArticle

24 Scopus citations


We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name ‘Cy-droplet’, has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a ‘microbubble condensation’ method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical ‘triggerability’ can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

Original languageEnglish (US)
Pages (from-to)26-36
Number of pages11
StatePublished - Jun 1 2017



  • Droplet
  • Microbubble
  • Multispectral optoacoustic tomography (MSOT)
  • Optical/acoustic vaporisation
  • Phase-change contrast agent
  • Photoacoustic
  • Ultrasound

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

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