Table 1. Quantification of the Multimodal (FLIM-UBM-PAI) Data for Plaque Characterization (4 Locations).

Region scanning distance/ Modality	ROI-1 1.1 – 3.0 mm	ROI-2 3.0 – 8.1 mm	ROI-3 8.1 – 11.4 mm	ROI-4 11.4 – 11.8 mm
FLIM (lifetime - ns) 390 nm 450 nm 540 nm	2.03 ± 0.02 2.19 ± 0.01 2.26 ± 0.04	2.48 ± 0.02 2.45 ± 0.02 2.53 ± 0.03	2.09 ± 0.02 2.24 ± 0.01 2.40 ± 0.01	3.0 ± 0.05 2.63 ± 0.05 2.57 ± 0.01
UBM: Image evaluation Main features	Delineation of intima and media layers	Hypoechoic & acoustic shadowing	Delineation of intima and media layers	Thickened fibrotic cap
PAI: Feature evaluation	Hot spot (artifact from sample holding pin)	High PA intensity & hot spots	Delineation of intima and media layers & hot spots	Moderate PA intensity from fibrous cap
Histology	Thin–intima elastin–rich media	Heterogenous composition (collagen, lipids, calcification) and microstructure	Thin–intima elastin–rich media	Collagen-rich area
Lifetime (ns) features in literature* [23]	Intima thickening 1.9-2.0	Fibro–lipidic plaque 2.4-2.5	Intima thickening 1.9-2.0	Fibrotic plaque 2.6-3.0

*Average fluorescence lifetime values at 390 nm.