Evaluation of the Usefulness of Virtual Chromoendoscopy with Different Color Modes in the MiroCam® System for Characterization of Small Bowel Lesions

Virtual Chromoendoscopy in Capsule Endoscopy: A Narrative Review

The usefulness of virtual chromoendoscopy (VC) in capsule endoscopy (CE) isa controversial issue, with conflicting studies regarding its efficacy. FICE and a blue filter were embedded in the PillCamTM software, with the aim to assist readers in identifying the source of obscure gastrointestinal (GI) bleeding (OGIB), coeliac disease mucosal changes and other small and large bowel lesions, including polyps and tumors. This review aims to summarize the existing evidence on the value of VC in the visualization and identification of different types of pathology. Overall, VC in CE with FICE 1 and 2 can be a useful adjunctive tool and may increase the visibility of pigmented lesions, such as angiectasias and ulcers. However, it does not appear to improve the detection of polyps or tumors. On the other hand, the role of FICE 3 and the blue filter appears to be limited. FICE may also be helpful in differentiating hyperplastic and adenomatous colonic polyps during colon capsule endoscopy, although more evidence is needed.

Image-Enhanced Capsule Endoscopy Improves the Identification of Small Intestinal Lesions

Image-enhanced endoscopy is useful for diagnosing and identifying lesions in the gastrointestinal tract. Recently, image-enhanced endoscopy has become a breakthrough technology that has attracted significant attention. This image enhancing technology is available for capsule endoscopy, which is an effective tool for small intestinal lesions and has been applied in flexible spectral color enhancement technology and in contrast capsule like narrow-band imaging. In this field, most researchers focus on improving the visibility and detection of small intestinal lesions. This review summarizes previous studies on image-enhanced capsule endoscopy and aims to evaluate the efficacy of this technology.

Clinical Performance of New Software to Automatically Detect Angioectasias in Small Bowel Capsule Endoscopy

Background

Video capsule endoscopy (VCE) revolutionized the diagnosis and management of obscure gastrointestinal bleeding, though the rate of detection of small bowel lesions by the physician is still disappointing. Our group developed a novel algorithm (CMEMS-Uminho) to automatically detect angioectasias which display greater accuracy in VCE static frames than other methods previously published. We aimed to evaluate the algorithm overall performance and assess its diagnostic yield and usability in clinical practice.

Methods

Algorithm overall performance was determined using 54 full-length VCE recordings. To assess its diagnostic yield and usability in clinical practice, 38 VCE examinations with the clinical diagnosis of angioectasias consecutively performed (2017-2018) were evaluated by three physicians with different experiences. The CMEMS-Uminho algorithm was also applied. The performance of the CMEMS-Uminho algorithm was defined by a positive concordance between a frame automatically selected by the software and a study independent capsule endoscopist.

Results

Overall performance in complete VCE recordings was 77.7%, and diagnostic yield was 94.7%. There were significant differences between physicians in regard to global detection rate (p < 0.001), detection rate per capsule (p < 0.001), diagnostic yield (p = 0.007), true positive rate (p < 0.001), time (p < 0.001), and speed viewing (p < 0.001). The application of CMEMS-Uminho algorithm significantly enhanced all readers' global detection rate (p < 0.001) and the differences between them were no longer observed.

Conclusion

The CMEMS-Uminho algorithm detained a good overall performance and was able to enhance physicians' performance, suggesting a potential usability of this tool in clinical practice.

Evaluation of the sensitivity of the Express View function in the Mirocam® capsule endoscopy software

Background: A new computer algorithm called Express-View has recently been introduced by Mirocam, but data concerning its application and efficacy are scarce.Objective: To evaluate the lesion detection rate, per-patient sensitivity and the diagnostic accuracy using Express-View.Methods: All patients who performed CE between January 2018 and June 2019, whose indication was obscure gastrointestinal bleeding (OGIB) and with findings on CE, were included. Lesions identified in conventional reading were selected and considered as reference.Results: Eighty-nine patients were included, 50.6% male, with a mean age of 68.4 years-old (±12.3). The Express-View mode detected 85.5% of lesions previously detected by conventional reading (524 out of 613). There were 89 missed lesions, mainly erosions or ulcers (44.9%) and angioectasias (38.2%). The lesion detection rate was found to be lower in the jejunum and ileum compared to extra-small bowel locations and duodenum (p = .04). Although Express-View had a per-patient sensitivity for all lesions of 56.2% and a per-patient sensitivity for all clinically significant lesions of 83.1%, it achieved a diagnostic accuracy of 91%.Conclusions: The per-patient sensitivity for all lesions was shown to be below expectations, although the lesion detection rate, the per-patient sensitivity for all clinically significant lesions, and the diagnostic accuracy were shown to be higher.