Ultra high magnification endoscopy: Is seeing really believing?

Table 1 Comparison of endocytoscopy and confocal endomicroscopy

	ECS	CEM
Available systems
Probe based	Olympus (Japan)	Optiscan (Australia) endomicroscope integrated into Pentax (Japan) endoscope
Integrated	Olympus (Japan)	Cellvizio, Mauna Kea Technologies (France)
Max resolution	NA	1024 × 1024 pixels with integrated system (lower with probe based system)
Max magnification	1400 × (probe) 580 × (integrated)	1000 ×
Field of view	300 μm × 300 μm (450 x magnification)	475 μm × 475 μm
	120 μm × 120 μm (1125 x magnification)
Depth of imaging	Superficial mucosal layer only	Probe based: Different probes allow for different imaging depths
		Integrated system: Variable, up to 250 μm below surface (lamina propria)
Contrast agents	0.5%-1% methylene blue	Fluorescein sodium
	0.25% toluidine blue	Acriflavine
Commercially available?	No	Yes
Advantages	Higher magnification than CEM	Can visualize subsurface structures up to 250 μm
		Commercially available
Disadvantages	Cannot visualize subsurface structures	Lower magnification than ECS
	Requires mucolytic preparation of tissue	Two contrast agents required for optimal imaging
	Not commercially available

ECS: Endocytoscopy; CEM: Confocal endomicroscopy; NA: Not available.