Open Access
CC BY-NC-ND 4.0 · Endosc Int Open 2018; 06(04): E462-E469
DOI: 10.1055/a-0573-1044
Original article
Owner and Copyright © Georg Thieme Verlag KG 2018

Development and validation of an automated algorithm to evaluate the abundance of bubbles in small bowel capsule endoscopy

Olivia Pietri
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
,
Gada Rezgui
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
,
Aymeric Histace
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
,
Marine Camus
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
3   Sorbonne University, Paris, France
,
Isabelle Nion-Larmurier
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
,
Cynthia Li
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
4   College of Arts and Sciences, Drexel University, Philadelphia, Pennsylvania, United States
,
Aymeric Becq
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
,
Einas Abou Ali
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
,
Olivier Romain
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
,
Ulriikka Chaput
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
,
Philippe Marteau
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
,
Christian Florent
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
,
Xavier Dray
1   APHP Saint Antoine Hospital, Department of Hepatogastroenterology, Paris, France
2   ETIS, ENSEA, Cergy-Pontoise University, Cergy-Pontoise, France
3   Sorbonne University, Paris, France
› Author Affiliations
Further Information

Publication History

submitted 10 August 2017

accepted after revision 03 January 2018

Publication Date:
29 March 2018 (online)

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Abstract

Background and study aims Bubbles can impair visualization of the small bowel (SB) mucosa during capsule endoscopy (CE). We aimed to develop and validate a computed algorithm that would allow evaluation of the abundance of bubbles in SB-CE still frames.

Patients and methods Two sets of 200 SB-CE normal still frames were created. Two experienced SB-CE readers analyzed both sets of images twice, in a random order. Each still frame was categorized as presenting with < 10 % or ≥ 10 % of bubbles. Reproducibility (κ), sensitivity (Se), specificity (Sp), receiver operating characteristic curve, and calculation time were measured for different algorithms (Grey-level of co-occurrence matrix [GLCM], fractal dimension, Hough transform, and speeded-up robust features [SURF]) using the experts’ analysis as reference. Algorithms with highest reproducibility, Se and Sp were then selected for a validation step on the second set of frames. Criteria for validation were κ = 1, Se ≥ 90 %, Sp ≥ 85 %, and a calculation time < 1 second.

Results Both SURF and GLCM algorithms had high operating points (Se and Sp over 90 %) and a perfect reproducibility (κ = 1). The validation step showed the GLCM detector strategy had the best diagnostic performances, with a Se of 95.79 %, a Sp of 95.19 %, and a calculation time of 0.037 seconds per frame.

Conclusion A computed algorithm based on a GLCM detector strategy had high diagnostic performance allowing assessment of the abundance of bubbles in SB-CE still frames. This algorithm could be of interest for clinical use (quality reporting) and for research purposes (objective comparison tool of different preparations).