Time-Resolved Fluorescence Imaging Without Lifetime Fitting
SUMMARY
UCLA investigators have developed a novel method to obtain time-resolved fluorescence imaging (TRFI) without the need to extract a fluorescence lifetime. Compared to conventional TRFI, this novel method is reliable, simple, time-saving and can dramatically improve biomedical applications of TRFI.
BACKGROUND
Time-resolved fluorescence imaging is an effective tool to study complex biological samples. In medicine, the distribution in space of any fluorescent marker can be exploited for diagnostic purposes. Images using this technique are acquired by obtaining the lifetime pattern of the sample. This is complicated due to the fact that lifetime-extraction to obtain fluorescence images may not be reliable.Fluorescence decay fitting and lifetime estimation methods have resolution limits, especially when it comes to multiple fluorophores. A simple and accurate method to obtain fluorescence image without lifetime-extraction is a desirable option for time-resolved fluorescence imaging.
INNOVATION
Researchers at UCLA have developed a method to obtain time-resolved fluorescence imaging (TRFI) without the need of lifetime fitting. The method first utilizes the lifetime differences of fluorophores to normalize images sampled at multiple fluorescence decay time points. The method then applies division and intensification on images sampled when all the fluorophores are still fluorescing.
APPLICATIONS
- Cancer detection in a broad range of imaging procedures
- Cosmetic application for determination of collagen and elastin ratio
- Identification of unknown substances in medical forensics
ADVANTAGES
- Provides rapid determination of the relative lifetime within an image
- Simpler and more reliable
STATE OF DEVELOPMENT
The capability of both methods has been tested by using Fluorescein and Rhodamine-B as samples. Both methods show the ability to distinguish fluorophores from each other. In addition, the methods can avoid the effect of non-uniformity of the fluorescence intensity.