Fluorescence imaging using near-infrared (NIR) fluorescent contrast agents is increasingly being investigated as intraoperative tool to visualize, in real-time, tissues of interest such as tumors, lymph nodes or nerve bundles. Generally, spectral imaging systems are used that measure the intensity of fluorescent signals. However, to aid in a more specific detection of these fluorescent signals, fluorescence lifetime can be added to the image. The lifetime is independent of the intensity and in addition, multiple tracers emitting around the same wavelengths can still be distinguished based on their difference in lifetime. Imaging lifetimes, however, requires a much more advanced imaging system. None of the currently approved fluorescence guidance systems support fluorescence lifetime and today’s available lifetime imaging technology (TCSPC, ICCD) does not allow imaging the sub-nanosecond lifetimes of NIR dyes with the efficiency needed to reach video frame rates. In this paper, we present a 32×32-pixel proof-of-concept camera based on our novel CAPS-pixel based gated image sensor. This camera is specifically targeted at imaging fluorescence lifetimes at NIR wavelengths with high efficiency for the use in fluorescence-guided surgery and is a first step towards a full camera with video resolution at video frame rates. We describe the camera system and how it is used to image fluorescence lifetimes. Next, we show the lifetime imaging capability by imaging the lifetimes of two different nanosecond visible dyes (fluorescein and acridine orange) in cuvette and two more challenging (sub-)nanosecond NIR dyes (ICG and IRDye800CW). Lastly, we validate the camera by imaging NIR fluorescence phantoms in a mouse.
Original languageEnglish
Title of host publicationSPIE Proceedings Vol. 10862
Subtitle of host publicationMolecular-Guided Surgery: Molecules, Devices, and Applications V
Number of pages9
Publication statusPublished - 7 Mar 2019
EventSPIE Photonics West 2019 - Moscone center, San Francisco, United States
Duration: 2 Feb 20197 Feb 2019


ConferenceSPIE Photonics West 2019
CountryUnited States
CitySan Francisco
Internet address

    Research areas

  • CAPS, Fluorescence lifetime imaging, gated image sensor, fluorescence-guided surgery, pre-clinical imaging

ID: 45744536