| 1. |
- Iakovidis, Dimitris K., et al.
(författare)
-
Robotic validation of visual odometry for wireless capsule endoscopy
- 2016
-
Ingår i: IST 2016 - 2016 IEEE International Conference on Imaging Systems and Techniques, Proceedings. - 9781509018178 ; , s. 83-87
-
Konferensbidrag (refereegranskat)abstract
- Wireless capsule endoscopy (WCE) is the prime diagnostic modality for the small-bowel. It consists in a swallowable color camera that enables the visual detection and assessment of abnormalities, without patient discomfort. The localization of the capsule is currently performed in the 3D abdominal space using radiofrequency (RF) triangulation. However, this approach does not provide sufficient information for the localization of the capsule, and therefore for the localization of the detected abnormalities, within the gastrointestinal (GI) lumen. To cope with this problem, we have recently proposed a method for visual tracking of the capsule endoscope (CE). It is based solely on visual features extracted from the captured images during the journey of the CE in the GI tract, enabling therefore visual odometry. Due to lack of ex-vivo or in-vivo ground truth data, the feasibility of that method was assessed using relative measurements in an image-based simulation experiment. In this paper, we make one step forward towards the assessment of the absolute localization capabilities of visual odometry using a calibrated in-vitro experimental setup. The obtained results validate the feasibility of the proposed approach, highlight the difficulty of this complex problem, and reveal the challenges ahead.
|
|
| 2. |
- Koulaouzidis, Anastasios, et al.
(författare)
-
Association Between Fecal Calprotectin Levels and Small-bowel Inflammation Score in Capsule Endoscopy : A Multicenter Retrospective Study
- 2016
-
Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 61:7, s. 2033-2040
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Accurate inflammation reporting in capsule endoscopy (CE) is important for diagnosis and monitoring of treatment of inflammatory bowel disease (IBD). Fecal calprotectin (FC) is a highly specific biomarker of gut inflammation. Lewis score (LS) was developed to standardize quantification of inflammation in small-bowel (SB) CE images.GOALS: Multicenter retrospective study aiming to investigate correlation between LS and FC in a large group of patients undergoing CE for suspected or known small-bowel IBD, and to develop a model for prediction of CE results (LS) based on FC levels.STUDY: Five academic centers and a district general hospital offering CE in UK, Finland, Sweden, Canada, and Israel. In total, 333 patients were recruited. They had small-bowel CE and FC done within 3 months.RESULTS: Overall, correlation between FC and LS was weak (r s: 0.232, P < 0.001). When two clinically significant FC thresholds (100 and 250 μg/g) were examined, the r s between FC and LS was 0.247 (weak) and 0.337 (moderate), respectively (P = 0.307). For clinically significant (LS ≥ 135) or negative (LS < 135) for SB inflammation, ROC curves gave an optimum cutoff point of FC 76 μg/g with sensitivity 0.59 and specificity 0.41.LIMITATIONS: Retrospective design.CONCLUSIONS: LS appears to show low correlation with FC as well as other serology markers of inflammation. FC does not appear to be a reliable biomarker for significant small-bowel inflammation. Nevertheless, FC level ≥ 76 μg/g may be associated with appreciable visual inflammation on small-bowel CE in patients with negative prior diagnostic workup.
|
|
| 3. |
- Wagner, Michael, et al.
(författare)
-
Elevated fecal levels of eosinophil granule proteins predict collagenous colitis in patients referred to colonoscopy due to chronic non-bloody diarrhea
- 2016
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 51:7, s. 835-841
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Colonoscopy with biopsy sampling is often performed to detect collagenous colitis (CC) and lymphocytic colitis (LC) in patients with chronic non-bloody diarrhea. However, the diagnostic yield is low and incurs high costs. Fecal calprotectin (FC) and myeloperoxidase (MPO) indicate intestinal inflammation in ulcerative colitis (UC) and Crohn's disease (CD). In CC, elevated fecal levels of eosinophil protein X (EPX) and eosinophil cationic protein (ECP) have been reported. We aimed to evaluate if F-EPX, F-ECP, FC, and F-MPO could predict the diagnostic outcome in patients with chronic non-bloody diarrhea referred to colonoscopy. We also evaluated serum (S) EPX and ECP in this regard. Methods: Of 67 included patients, 63 (94%) underwent colonoscopy with biopsy sampling. Fecal EPX, F-ECP, FC, F-MPO, S-EPX, and S-ECP were analyzed. Results: Diagnostic outcome: normal: n = 46 (73%), CC: n = 9 (14%), LC: n = 4 (6%), UC: n = 2 (3%), CD: n = 2 (3%). Higher levels of F-EPX and F-ECP were found in CC compared to a normal diagnostic outcome (p = 0.01). No change was noted in any of the fecal markers in LC. When all of the fecal markers were normal the probability of a normal diagnostic outcome was 92%. We found no differences in S-EPX and S-ECP between the groups. Conclusion: Elevated F-EPX and F-ECP could predict CC. None of the fecal markers predicted LC. Serum-EPX and S-ECP are not useful for the diagnosis of CC, LC, UC, or CD. With normal levels in all of the analyzed fecal markers, there is a low probability of a pathologic diagnostic outcome.
|
|
