Table 1.

Comparison of properties of the imaging modalities^a

Imaging modality	Spatial resolution	Imaging depth	Chemical sensitivity	Potential applications
EM	1 nm	0.1 μm	N.A.	Biomineralization, biomaterial surface structure, pore formation, cell–biomaterial interaction
CM	0.4 μm	0.1 mm	High	Cell behavior, cell tracking, gene expression, cellular substructure, functional activity
MPM	1 μm	1 mm	High	Biomaterial architecture, cell tracking, functional activity
OR-PAM	2.5 μm	1 mm	High	Cell tracking, functional activity, fluid dynamics, cell–biomaterial interaction
OCT	10 μm	2 mm	Low	Vascularization, biomaterial architecture, functional activity
AR-PAM	45 μm	3 mm	High	Vascularization, biomaterial architecture, cell metabolism, functional activity
US (20 MHz)	165 μm	3 cm	Low	Fluid dynamics, mechanics, spatial patterning of cells, functional activity

^aAbbreviations: EM electron microscopy, CM confocal microscopy, MPM multi-photon microscopy, OR-PAM optical resolution photoacoustic microscopy, OCT optical coherence tomography, AR-PAM acoustic resolution photoacoustic microscopy, US ultrasound imaging, N.A. not available