Definition of multi-image phasor analysis

Photonics Dictionary

multi-image phasor analysis: Multi-image phasor analysis is a computational method used in fluorescence microscopy for analyzing complex datasets consisting of multiple images or time-series of images. This technique extends the principles of phasor analysis, a method commonly used in fluorescence lifetime imaging microscopy (FLIM), to analyze spatial and temporal variations in fluorescence signals across multiple images simultaneously.

Phasor analysis: Phasor analysis is a mathematical technique used to analyze fluorescence lifetime data in FLIM. It represents each pixel or region of interest (ROI) in the image as a point in a two-dimensional plot known as the phasor plot, where the coordinates correspond to the real and imaginary components of the Fourier transform of the fluorescence decay curve. Different molecular species or cellular environments exhibit distinct phasor coordinates, allowing for the identification and quantification of fluorophores with different lifetimes.

Extension to multi-image analysis: Multi-image phasor analysis extends the phasor analysis approach to analyze datasets consisting of multiple images acquired under different experimental conditions, time points, or spatial locations. Each pixel or ROI across the entire dataset is represented as a point in a multi-dimensional phasor space, where each dimension corresponds to a different image or time point.

Data representation: In multi-image phasor analysis, the fluorescence intensity or other relevant parameters from each image are used to construct a multi-dimensional dataset. Each pixel or ROI in the dataset is then represented as a point in the multi-dimensional phasor space.

Dimensionality reduction and visualization: Multi-dimensional phasor datasets can be visualized using dimensionality reduction techniques such as principal component analysis (PCA) or t-distributed stochastic neighbor embedding (t-SNE). These techniques reduce the complexity of the dataset while preserving the underlying relationships between pixels or ROIs, allowing for visualization and interpretation of the data.

Applications: Multi-image phasor analysis has diverse applications in fluorescence microscopy, including the analysis of dynamic cellular processes, protein-protein interactions, and spatial heterogeneity in biological samples. It can be used to identify and characterize different subpopulations of cells or regions within tissues based on their fluorescence properties across multiple images or time points.

Data interpretation: Multi-image phasor analysis enables researchers to extract quantitative information from complex fluorescence datasets and to identify patterns or correlations that may not be apparent from individual images or time points. By analyzing spatial and temporal variations in fluorescence signals, it provides insights into the underlying biological processes and molecular interactions within cells and tissues.