Introduction Blue mode (BM) is one of the features of proprietary software (RAPID®; Medtronic Ltd) for capsule endoscopy (CE) review. BM is a colour coefficient shift of light in the short wavelength range (490–430 nm) superimposed onto a white light (WL) image.¹ Recently, studies have shown that BM improves visualisation of vascular and erythematous non-vascular CE lesions.^1,2 We aimed to objectively evaluate the validity of BM in CE in assessing the surface annotations of angiectasias as compared to WL.

Methods A set of 100 anonymised images of angiectasias was used, with the lesions captured both in WL and BM in the same pose. The entire dataset is available in our online database, KID (http://is-innovation.eu/kid). Three reviewers (2 experts and one novice in CE review) graphically annotated the lesions using Ratsnake annotation tool (http://is-innovation.eu/ratsnake). The images were reviewed in WL and BM twice to estimate the inter- and intra-observer variability (at least 7 days apart). The Jaccard index (JI) was used to assess the similarity (agreement) of the annotations performed by the reviewers.

Results Under WL, the average inter-observer agreement ranged between 65±15% (novice vs. expert reviewer) and 67±13% (between experts), while the intra-observer agreement, ranged between 69±17% and 71±13%. Under BM, the average inter-observer agreement ranged between 56±19% (novice vs. expert reviewer) and 78±18% (between experts). The average intra-observer agreement in BM ranged between 69±20% and 73±8.

Conclusion BM CE image review does not improve significantly the surface annotations of angiectasias -as compared to WL- for expert or novice reviewers.^3,4

References 1 Abdelaal UM, et al. Blue mode imaging may improve the detection and visualisation of small-bowel lesions: A capsule endoscopy study. Saudi J Gastroentero 2015;21:418–22.

2 Krystallis C, et al. Chromoendoscopy in small bowel capsule endoscopy: Blue mode or Fuji Intelligent Colour Enhancement? Dig Liver Dis 2011;43:953–7.

3 Koulaouzidis A, et al. Blue mode does not offer any benefit over white light when calculating Lewis score in small-bowel capsule endoscopy. World J Gastrointest Endosc 2012;4:33–7.

4 Koulaouzidis A, et al. QuickView in small-bowelcapsule endoscopy is useful in certain clinical settings, but QuickView with BlueMode is of no additional benefit. Eur J Gastroenterol Hepatol 2012;24:1099–104.

Disclosure of Interest None Declared