Assessment of photobleaching during endoscopic autofluorescence imaging of the lower GI tract

Douplik, Alexandre; Chen, Dean; Akens, Margarete K.; Zanati, Simon; Cirocco, Maria; Bassett, Nancy; Marcon, Norman E.; Fengler, John; Wilson, Brian C.

doi:10.1002/lsm.20892

Cited by 8 publications

(4 citation statements)

References 18 publications

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“…Since the B4 algorithm exploits a different spectral range from that used currently in autofluorescence endoscopy systems which use primarily the green (~490-550 nm) range for the autofluorescence detection [32], the two techniques are spectrally compatible. This approach would provide realtime images that would not require the endoscopist to make detailed examination and interpretation of the microvascular architecture per se and so could be faster and less subjective than NBI.…”

Section: Resultsmentioning

confidence: 99%

Diffuse reflectance spectroscopy in Barrett’s Esophagus: developing a large field‐of‐view screening method discriminating dysplasia from metaplasia

Douplik

Zanati

Saiko

et al. 2012

Journal of Biophotonics

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We evaluated diffuse reflectance spectroscopy implemented as a small field‐of‐view technique for discrimination of dysplasia from metaplasia in Barrett’s esophagus as an adjuvant to autofluorescence endoscopy. Using linear discriminant analysis on 2579 spectra measured in 54 patients identified an optimum a 4‐wavelength classifier (at 485, 513, 598 and 629 nm). Sensitivity and specificity for a test data set were 0.67 and 0.85, respectively. Spectroscopic results show that this technique could be implemented in wide‐field imaging mode to improve the accuracy of existing endoscopy techniques for finding early pre‐malignant lesions in Barrett’s esophagus. Results show that the discrimination occurs likely due to redistribution of blood content in the tissue sensed by the optical probing with the wavelength‐dependent sampling depth. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Resultsmentioning

confidence: 99%

Diffuse reflectance spectroscopy in Barrett’s Esophagus: developing a large field‐of‐view screening method discriminating dysplasia from metaplasia

Douplik

Zanati

Saiko

et al. 2012

Journal of Biophotonics

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“…Both LIF fiber configurations can also be used for detecting biochemicals within the colon. Though fluorescence emission from collagen, NADH, and FAD, as well as oxyhemoglobin absorption are observed when tissue is excited with 325 nm light [11], the dichroic filter can be replaced in the single fiber setup to enable use of other excitation wavelengths, leading to the preferential excitement of different endogenous or exogenous fluorophores [37]. …”

Section: Discussionmentioning

confidence: 99%

Novel focused OCT-LIF endoscope

Wall

Bonnema

Barton

2011

Biomed. Opt. Express

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Combined optical coherence tomography (OCT) and laser-induced fluorescence (LIF) endoscopy has shown higher sensitivity and specificity for distinguishing normal tissue from adenoma when compared to either modality alone. Endoscope optical design is complicated by the large wavelength difference between the two systems. A new high-resolution endoscope 2 mm in diameter is presented that can create focused beams from the ultraviolet to near-infrared. A reflective design ball lens operates achromatically over a large wavelength range, and employs TIR at two faces and reflection at a third internal mirrored face. The 1:1 imaging system obtains theoretically diffraction-limited spots for both the OCT (1300 nm) and LIF (325 nm) channels.

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“…EGDs were performed using WLE followed by AFI endoscopy, using conventional fiber-optic gastroscope (GIF H180) with fluorescence endoscopy system (PinPoint ™ , Novadaq, Canada) described below in Data collection section [44].…”

Section: Endoscopic Proceduresmentioning

confidence: 99%

Normalized autofluorescence imaging diagnostics in upper GI tract: a new method to improve specificity in neoplasia detection

Krauss¹,

Douplik²,

Albrecht³

et al. 2011

Z Gastroenterol

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Background & Aims: This study was performed to improve the autofluorescence imaging (AFI) in the upper GI tract by applying a new method of normalized autofluorescence (NAFI) obtained via tri-modal imaging. Objective: NAFI may provide lower false positive rate to achieve ultimately better specificity at acceptable sensitivity. Patients and methods: This is a prospective, controlled single-centre study. 18 patients with suspected esophagus or stomach cancer undergoing esophagogastroduodenoscopy (EGD) were enrolled between February and May 2010. After endoscopy each patient was assigned into one of two groups: (1) non-cancer, including inflammation; (2) cancer group. EGDs were performed using video white light endoscopy, followed by AFI/NAFI. The targeted biopsy samples were taken from the abnormal areas as well as from adjacent mucosa. NAFI was compared versus AFI for cancer diagnostics in terms of specificity and sensitivity. Results: NAFI detected all neoplastic lesions. WLE or NBI detected no additional neoplasia. The AFI displayed mucosal inflammation and carcinomas of esophagus and stomach as dark red color, the normal mucosa background was displayed as light green. The NAFI didn't differentiate inflamed tissue from normal in majority of cases, but in tumorous mucosa, the cancer areas were detected precisely. AFI shows 100% sensitivity but 50% specificity which correlates with previous literature data. On the other hand, NAFI demonstrated lower sensitivity (88%) but higher specificity compared to AFI (69%). Conclusions: Measuring the NAFI instead of the AFI was found improving the specificity of cancer diagnosis. Use of fiber-optic endoscopes to analyze AFI and possible endoscopic and histological sampling error are the main potential limitations of this method.

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Assessment of photobleaching during endoscopic autofluorescence imaging of the lower GI tract

Cited by 8 publications

References 18 publications

Diffuse reflectance spectroscopy in Barrett’s Esophagus: developing a large field‐of‐view screening method discriminating dysplasia from metaplasia

Diffuse reflectance spectroscopy in Barrett’s Esophagus: developing a large field‐of‐view screening method discriminating dysplasia from metaplasia

Novel focused OCT-LIF endoscope

Normalized autofluorescence imaging diagnostics in upper GI tract: a new method to improve specificity in neoplasia detection

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