Risk assessment of plaque rupture and future cardiovascular events (CVENT) by multi-spectral photoacoustic imaging

Atherosclerosis und its related complications are considered as the most common cause of death in western societies. The main goal of the CVENT consortium is the development of a portable multimodality, multi-wavelength Photoacoustic imaging system with a hand-held PA/US probe for screening, in-depth diagnosis and treatment monitoring of the vulnerability of atherosclerotic plaques by means of plaque: composition and structure, size and shape, as well as mechanical properties. The CVENT consortium will focus on the following ground-breaking interdisciplinary research and development objectives to achieve this goal:

Photoacoustic system engineering to develop:

  • Multi-wavelength diode laser beam sources with ultra-high pulse power (2 mJ per wavelength) and short pulse duration (40-80 ns).
  • A highly efficient diode laser driver, allowing passive cooling of the hand-held probe.
  • A multi-spectral diode-stack beam forming based on diffractive optical elements (DOE) that is small enough to be integrated in a hand-held probe.
  • A high-sensitivity ultrasound transducer integrated in a multiwavelength hand-held PA/US probe.
  • The CVENT ultrasound platform with a multimodality (hybrid) front-end - for US and PA data beam forming - connected to an embedded low-power-consumption high-performance computing unit based on state-of-the-art system-on-chip (SoC) technology allowing for realtime signal processing of the PA/US data.

CVENT_Overview Overview of the CVENT project

Advanced PAI signal processing to:

  • Characterize and classify plaque by multi-wavelength PAI and estimation of tissue composition together with the quantitative parameters speed-of-sound by ultrasound techniques, contrast in Grueneisen coefficient by thermal provocation, and mechanical properties by ultrafast plain wave strain imaging.
  • Reduce measurement noise in the multi-wavelength PA images by multiple input/multiple output multi-spectral filters with adaptively optimized combinations of laser pulses.
  • Suppress clutter signals - by more than 10dB at the imaging depth of 3 cm - that are superimposing the weaker PA signals by exploiting simultaneous US measurements, clutter spectral behavior, and Doppler shifts of clutter from the flowing blood of large vessels.
  • Improve PAI image quality by optimizing PAI/US hybrid reconstruction techniques.

PAI system verification and validation to: CVENT_Szene

  • Verify the CVENT PAI system in-vitro and ex-vivo using human carotid plaques obtained from surgical interventions.
  • Perform a first clinical validation by imaging plaque prior to and during surgery and validated experimentally after excision in 30 patients.

Official Project Homepage: CVENT

CVENT is supported by the European Commision's Horizon 2020 research and innovation programme under grant agreement No 731771, Photonics Private Public Partnership, and is supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0160.

Project duration: November 2016 - Oktober 2020