From the surface to the single cell: Novel endoscopic approaches in inflammatory bowel disease

Table 1 Techniques and modes of advanced endoscopic imaging with advantages and indications

Endoscopic technique	Modes	Advantages	Disadvantages	Indications
White light endoscopy (WLE)	Standard definition colonoscopy (SD)	Widely spread	No sufficient discrimination between inflammation and dysplasia	Routine assessment of mucosal inflammation
	High definition colonoscopy(HD)	Can detect significantly more dysplastic lesion in IBD than SD[108]	Increased costs compared to SD	in combination with DBC: cancer surveillance of IBD patient[109,110]
Dye based chromo-endoscopy (DBC)	Indigo-carmine (0.8%)[109,110]	Superior for the detection of dysplastic lesions in IBD[20,21,55,56,109,110]	Increase in time and effort, dye-pooling	Method of choice for cancer surveillance in IBD[12,34,35,109,110]
	Methylene blue (1%)[109,110]
Dye less chromo-endoscopy (DLC)
Optical DLC	NBI CBI	Readily available (push-of-a-button technologies)[22,31,66] improved prediction of disease extent and disease activity compared to WLE[67-69,71]	NBI: results for dysplasia detection in IBD heterogenous	NBI: not recommended as a replacement for DBC for cancer surveillance in IBD[109,110]
Digital DLC	i-scan FICE SPIES		i-scan: no data for dysplasia detection in IBD yet
Confocal laser endomicroscopy (CLE)	pCLE iCLE	Real time histologic imaging with 1000-fold magnification, potentially improved delineation of degree and extent of mucosal inflammation[82]	Time- and cost-intensive procedure, expert skills required[22,31]	No routine indications
Endocytoscopy (EC)		Real time histologic imaging with up to 1390-fold magnification, potentially improved delineation of degree and extent of mucosal inflammation, can distinguish single inflammatory cells[88]	Time- and cost-intensive procedure, expert skills required[22,31,111]	No routine indications

CBI: Compound band imaging; DBC: Dye-based chromoendoscopy; DLC: Dye-less chromoendoscopy; FICE: Fuji intelligent color enhancement; HD: High definition; IBD: Inflammatory bowel diseases; iCLE: Integrated confocal laser endomicroscop; NBI: Narrow band imaging; SD: Standard definition; SPIES: Storz professional image enhancement systems; pCLE: Probe based confocal endomicroscopy.