Abstract

Time-dependent speckle holograms from inside tumor spheroids using short-coherence near-infrared light provide quantitative measures of the state of health of the tumor tissue. Holographic optical coherence imaging (OCI) records full-frame en face images from successive depths inside a tumor in a so-called “flythrough”. When the flythrough is stopped at a specified depth, the holographic features can be classified as variable (relating to cell motility and Brownian motion) or persistent (arising from specific structure such as necrosis inside the tumor) depending on their temporal variations. A strong trend is observed in the ratio of variable-to-persistent features in tumors that are healthy, metabolically poisoned, or chemically cross-linked. Autocorrelation times also reflect this trend. Depth-gated speckle holography provides a means to sample biologically significant areas without the need for cellular-scale spatial resolution, with possible relevance for intraoperative applications.

© 2003 SPIE