{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T22:28:27Z","timestamp":1769552907641,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,4,21]],"date-time":"2023-04-21T00:00:00Z","timestamp":1682035200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and objectives: Capsule endoscopy (CE) is a non-invasive method to inspect the small bowel that, like other enteroscopy methods, requires adequate small-bowel cleansing to obtain conclusive results. Artificial intelligence (AI) algorithms have been seen to offer important benefits in the field of medical imaging over recent years, particularly through the adaptation of convolutional neural networks (CNNs) to achieve more efficient image analysis. Here, we aimed to develop a deep learning model that uses a CNN to automatically classify the quality of intestinal preparation in CE. Methods: A CNN was designed based on 12,950 CE images obtained at two clinical centers in Porto (Portugal). The quality of the intestinal preparation was classified for each image as: excellent, \u226590% of the image surface with visible mucosa; satisfactory, 50\u201390% of the mucosa visible; and unsatisfactory, &lt;50% of the mucosa visible. The total set of images was divided in an 80:20 ratio to establish training and validation datasets, respectively. The CNN prediction was compared with the classification established by consensus of a group of three experts in CE, currently considered the gold standard to evaluate cleanliness. Subsequently, how the CNN performed in diagnostic terms was evaluated using an independent validation dataset. Results: Among the images obtained, 3633 were designated as unsatisfactory preparation, 6005 satisfactory preparation, and 3312 with excellent preparation. When differentiating the classes of small-bowel preparation, the algorithm developed here achieved an overall accuracy of 92.1%, with a sensitivity of 88.4%, a specificity of 93.6%, a positive predictive value of 88.5%, and a negative predictive value of 93.4%. The area under the curve for the detection of excellent, satisfactory, and unsatisfactory classes was 0.98, 0.95, and 0.99, respectively. Conclusions: A CNN-based tool was developed to automatically classify small-bowel preparation for CE, and it was seen to accurately classify intestinal preparation for CE. The development of such a system could enhance the reproducibility of the scales used for such purposes.<\/jats:p>","DOI":"10.3390\/medicina59040810","type":"journal-article","created":{"date-parts":[[2023,4,21]],"date-time":"2023-04-21T04:48:11Z","timestamp":1682052491000},"page":"810","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Design of a Convolutional Neural Network as a Deep Learning Tool for the Automatic Classification of Small-Bowel Cleansing in Capsule Endoscopy"],"prefix":"10.3390","volume":"59","author":[{"given":"Tiago","family":"Ribeiro","sequence":"first","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0340-0830","authenticated-orcid":false,"given":"Miguel Jos\u00e9","family":"Mascarenhas Saraiva","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"},{"name":"Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]},{"given":"Jo\u00e3o","family":"Afonso","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"}]},{"given":"Pedro","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"}]},{"given":"Francisco","family":"Mendes","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0484-4804","authenticated-orcid":false,"given":"Miguel","family":"Martins","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"}]},{"given":"Ana Patr\u00edcia","family":"Andrade","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"},{"name":"Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]},{"given":"H\u00e9lder","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"},{"name":"Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]},{"given":"Miguel","family":"Mascarenhas Saraiva","sequence":"additional","affiliation":[{"name":"Endoscopy and Digestive Motility Laboratory, ManopH, 4000-432 Porto, Portugal"}]},{"given":"Jo\u00e3o","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"INEGI\u2014Institute of Science and Innovation in Mechanical and Industrial Engineering, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9387-9872","authenticated-orcid":false,"given":"Guilherme","family":"Macedo","sequence":"additional","affiliation":[{"name":"Department of Gasteroenterology, S\u00e3o Jo\u00e3o University Hospital, Alameda Professor Hern\u00e2ni Monteiro, 4200-427 Porto, Portugal"},{"name":"Gastroenterology and Hepatology, WGO Gastroenterology and Hepatology Training Centre, 4050-345 Porto, Portugal"},{"name":"Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2407","DOI":"10.1111\/j.1572-0241.2005.00274.x","article-title":"A meta-analysis of the yield of capsule endoscopy compared to other diagnostic modalities in patients with obscure gastrointestinal bleeding","volume":"100","author":"Triester","year":"2005","journal-title":"Am. J. Gastroenterol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"796","DOI":"10.1111\/j.1440-1746.2010.06530.x","article-title":"Double balloon enteroscopy and capsule endoscopy for obscure gastrointestinal bleeding: An updated meta-analysis: Meta-analysis: DBE versus CE for OGIB","volume":"26","author":"Teshima","year":"2011","journal-title":"J. Gastroenterol. Hepatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4534","DOI":"10.3748\/wjg.v25.i31.4534","article-title":"Small bowel capsule endoscopy and treat-to-target in Crohn\u2019s disease: A systematic review","volume":"25","author":"Berre","year":"2019","journal-title":"World J. Gastroenterol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1079","DOI":"10.1111\/j.1440-1746.2010.06292.x","article-title":"Capsule endoscopy in small bowel tumors: A multicenter Korean study: Capsule endoscopy in small bowel tumors","volume":"25","author":"Cheung","year":"2010","journal-title":"J. Gastroenterol. Hepatol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1055\/s-0034-1391855","article-title":"Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline","volume":"47","author":"Pennazio","year":"2015","journal-title":"Endoscopy"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.3748\/wjg.14.1313","article-title":"Efficiency of bowel preparation for capsule endoscopy examination: A meta-analysis","volume":"14","author":"Niv","year":"2008","journal-title":"World J. Gastroenterol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1883","DOI":"10.1185\/03007995.2012.747953","article-title":"Meta-analysis: Efficacy of small bowel preparation for small bowel video capsule endoscopy","volume":"28","author":"Belsey","year":"2012","journal-title":"Curr. Med. Res. Opin."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1016\/S0016-5107(04)01879-6","article-title":"Bowel preparation increases the diagnostic yield of capsule endoscopy: A prospective, randomized, controlled study","volume":"60","author":"Viazis","year":"2004","journal-title":"Gastrointest. Endosc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1007\/s10620-006-9558-6","article-title":"Visualization of the small intestine using capsule endoscopy in healthy subjects","volume":"52","author":"Shiotani","year":"2007","journal-title":"Dig. Dis. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1080\/00365520410003209","article-title":"Capsule endoscopy: Role of bowel preparation in successful visualization","volume":"39","author":"Niv","year":"2004","journal-title":"Scand. J. Gastroenterol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1055\/a-0576-0566","article-title":"Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review","volume":"50","author":"Rondonotti","year":"2018","journal-title":"Endoscopy"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1053\/j.gastro.2016.12.032","article-title":"Clinical Practice Guidelines for the Use of Video Capsule Endoscopy","volume":"152","author":"Enns","year":"2017","journal-title":"Gastroenterology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"147","DOI":"10.5946\/ce.2013.46.2.147","article-title":"Guidelines for Bowel Preparation before Video Capsule Endoscopy","volume":"46","author":"Song","year":"2013","journal-title":"Clin. Endosc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"6802810","DOI":"10.1155\/2016\/6802810","article-title":"Optimal Bowel Preparation for Video Capsule Endoscopy","volume":"2016","author":"Song","year":"2016","journal-title":"Gastroenterol. Res. Pract."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"600","DOI":"10.4253\/wjge.v8.i17.600","article-title":"Review of small-bowel cleansing scales in capsule endoscopy: A panoply of choices","volume":"8","author":"Ponte","year":"2016","journal-title":"World J. Gastrointest. Endosc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"101612","DOI":"10.1016\/j.clinre.2020.101612","article-title":"Prospective evaluation of third-generation small bowel capsule endoscopy videos by independent readers demonstrates poor reproducibility of cleanliness classifications","volume":"45","author":"Dray","year":"2021","journal-title":"Clin. Res. Hepatol. Gastroenterol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"E183","DOI":"10.1055\/s-0034-1377521","article-title":"Analysis of a grading system to assess the quality of small-bowel preparation for capsule endoscopy: In search of the Holy Grail","volume":"2","author":"Goyal","year":"2014","journal-title":"Endosc. Int. Open"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.gie.2008.04.016","article-title":"A validation study of 3 grading systems to evaluate small-bowel cleansing for wireless capsule endoscopy: A quantitative index, a qualitative evaluation, and an overall adequacy assessment","volume":"69","author":"Brotz","year":"2009","journal-title":"Gastrointest. Endosc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1016\/j.dld.2021.04.024","article-title":"The impact of reader fatigue on the accuracy of capsule endoscopy interpretation","volume":"53","author":"Beg","year":"2021","journal-title":"Dig. Liver Dis."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1016\/j.gie.2013.06.026","article-title":"Wireless capsule endoscopy","volume":"78","author":"Wang","year":"2013","journal-title":"Gastrointest. Endosc."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Oh, D.J., Hwang, Y., and Lim, Y.J. (2021). A Current and Newly Proposed Artificial Intelligence Algorithm for Reading Small Bowel Capsule Endoscopy. Diagnostics, 11.","DOI":"10.3390\/diagnostics11071183"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1016\/S0893-6080(03)00115-1","article-title":"Subject independent facial expression recognition with robust face detection using a convolutional neural network","volume":"16","author":"Matsugu","year":"2003","journal-title":"Neural Netw."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"831","DOI":"10.1016\/j.gie.2020.04.039","article-title":"Deep learning for wireless capsule endoscopy: A systematic review and meta-analysis","volume":"92","author":"Soffer","year":"2020","journal-title":"Gastrointest. Endosc."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Kim, S.H., and Lim, Y.J. (2021). Artificial Intelligence in Capsule Endoscopy: A Practical Guide to Its Past and Future Challenges. Diagnostics, 11.","DOI":"10.3390\/diagnostics11091722"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1111\/den.13517","article-title":"Clinical usefulness of a deep learning-based system as the first screening on small-bowel capsule endoscopy reading","volume":"32","author":"Aoki","year":"2020","journal-title":"Dig. Endosc."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"932","DOI":"10.1055\/a-1301-3841","article-title":"A neural network-based algorithm for assessing the cleanliness of small bowel during capsule endoscopy","volume":"53","author":"Histace","year":"2021","journal-title":"Endoscopy"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"17706","DOI":"10.1038\/s41598-020-74668-8","article-title":"Automatic evaluation of degree of cleanliness in capsule endoscopy based on a novel CNN architecture","volume":"10","author":"Noorda","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4417","DOI":"10.1038\/s41598-021-81686-7","article-title":"Development of a deep learning-based software for calculating cleansing score in small bowel capsule endoscopy","volume":"11","author":"Nam","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Nam, J.H., Oh, D.J., Lee, S., Song, H.J., and Lim, Y.J. (2021). Development and Verification of a Deep Learning Algorithm to Evaluate Small-Bowel Preparation Quality. Diagnostics, 11.","DOI":"10.3390\/diagnostics11061127"},{"key":"ref_30","first-page":"2825","article-title":"Scikit-learn: Machine Learning in Python","volume":"12","author":"Pedregosa","year":"2011","journal-title":"J. Mach. Learn Res."},{"key":"ref_31","first-page":"300","article-title":"Artificial intelligence and capsule endoscopy: Unravelling the future","volume":"34","author":"Mascarenhas","year":"2021","journal-title":"Ann. Gastroenterol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1111\/den.13896","article-title":"Artificial intelligence and deep learning for small bowel capsule endoscopy","volume":"33","author":"Trasolini","year":"2021","journal-title":"Dig. Endosc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1111\/jgh.15341","article-title":"Artificial intelligence in small bowel capsule endoscopy - current status, challenges and future promise","volume":"36","author":"Dray","year":"2021","journal-title":"J. Gastroenterol. Hepatol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Pecere, S., Milluzzo, S.M., Esposito, G., Dilaghi, E., Telese, A., and Eusebi, L.H. (2021). Applications of Artificial Intelligence for the Diagnosis of Gastrointestinal Diseases. Diagnostics, 11.","DOI":"10.3390\/diagnostics11091575"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e000753","DOI":"10.1136\/bmjgast-2021-000753","article-title":"Deep learning and capsule endoscopy: Automatic identification and differentiation of small bowel lesions with distinct haemorrhagic potential using a convolutional neural network","volume":"8","author":"Saraiva","year":"2021","journal-title":"BMJ Open Gastroenterol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1159\/000518901","article-title":"Artificial Intelligence and Capsule Endoscopy: Automatic Detection of Small Bowel Blood Content Using a Convolutional Neural Network","volume":"29","author":"Saraiva","year":"2022","journal-title":"GE-Port. J. Gastroenterol."},{"key":"ref_37","first-page":"820","article-title":"Artificial intelligence and capsule endoscopy: Automatic detection of vascular lesions using a convolutional neural network","volume":"34","author":"Afonso","year":"2021","journal-title":"Ann. Gastroenterol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1007\/s11517-021-02486-9","article-title":"Automated detection of ulcers and erosions in capsule endoscopy images using a convolutional neural network","volume":"60","author":"Afonso","year":"2022","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1055\/a-0889-9586","article-title":"Performance measures for small-bowel endoscopy: A European Society of Gastrointestinal Endoscopy (ESGE) Quality Improvement Initiative","volume":"51","author":"Spada","year":"2019","journal-title":"Endoscopy"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"148","DOI":"10.5946\/ce.2017.030","article-title":"Quality Indicators for Small Bowel Capsule Endoscopy","volume":"50","author":"Shim","year":"2017","journal-title":"Clin. Endosc."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.1097\/MEG.0b013e32832b8d2f","article-title":"Bowel preparation before small bowel capsule endoscopy: What is the optimal approach?","volume":"21","author":"Koornstra","year":"2009","journal-title":"Eur. J. Gastroenterol. Hepatol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1097\/MEG.0b013e328365b9d4","article-title":"Should bowel preparation, antifoaming agents, or prokinetics be used before video capsule endoscopy? A systematic review and meta-analysis","volume":"26","author":"Kotwal","year":"2014","journal-title":"Eur. J. Gastroenterol. Hepatol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1388","DOI":"10.1016\/j.dld.2019.04.014","article-title":"Bowel preparation for small bowel capsule endoscopy\u2014The later, the better!","volume":"51","author":"Xavier","year":"2019","journal-title":"Dig. Liver Dis."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/j.gie.2016.08.037","article-title":"Preparation for video capsule endoscopy: A clear choice?","volume":"85","author":"Marshall","year":"2017","journal-title":"Gastrointest. Endosc."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"437","DOI":"10.5152\/tjg.2021.20279","article-title":"The Use of a PEG\/Ascorbate Booster Following Standard Bowel Preparation Improves Visualization for Capsule Endoscopy in a Randomized, Controlled Study","volume":"32","author":"Oliveira","year":"2021","journal-title":"Turk. J. Gastroenterol."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/4\/810\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:20:28Z","timestamp":1760124028000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/4\/810"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,4,21]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["medicina59040810"],"URL":"https:\/\/doi.org\/10.3390\/medicina59040810","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,4,21]]}}}