Summary: | 碩士 === 國立臺灣大學 === 臨床醫學研究所 === 99 === Abstract
Background: Image-enhanced endoscopy (IEE) compromises various means of enhancing contrast during endoscopy using dye, optical, and/or electronic methods. IEE allows improved visualization of lesions and can be used to gain insight into the pathology of the lesions. Recent progress in optics and computerized processing of endoscopic images, such as narrow band image (NBI) and Fuji intelligent Chromoendoscopy (FICE), provide an optical and/or electronic enhancement of the mucosal structures. Most recently, the i-Scan system, a novel endoscopic post-processing light filter technology, can provide detailed analysis based on surface architecture (surface enhancement), vascular change (i-Scan colon mode), or pit pattern (i-Scan p mode). However, it remains unclear whether this technology can distinguish neoplastic colon polyps from non-neoplastic ones when the polyps are less than 1 cm without magnification.
Aims: Evaluate the efficacy of high definition endoscopy combined with i-Scan system in differential diagnosis of colon polyps
Patients and methods: Images of colorectal polyps less than 1 cm in diameter were recruited from 54 patients who underwent non-magnified colonoscopy with surface enhancement (SE) and tone enhancement (TE). We calculated the sensitivity, specificity and accuracy in the prediction of histology. Inter- and intra-observer consistencies were evaluated by inviting 4 endoscopists to rate 45 static images.
Results: Overall sensitivity, specificity, and accuracy following the sequence of SE, TE-colon, and TE-pit pattern modes were 87.7% (95% confidence interval [CI]: 81.3-94.1%), 84.1% (76.9-91.3%), and 86.1% (79.4-92.8%), respectively. For each modality, the results were 75.0% (68.7-81.3%), 82.7% (77.2-88.2%) and 77.2% (71.1-83.3%) for SE; 71.1% (64.5-77.7%), 78.8 (72.8-84.8) and 73.3% (66.8-79.8%) for TE-colon mode; and 75.0% (68.7-81.3%), 80.8% (75.0-86.8%) and 76.7% (70.5-82.9%) for TE-pit pattern mode; their inter- and intra-observer agreements were all fair (κ range: 0.522-0.568) and good (0.605-0.694), respectively. When the same rater evaluated the same lesion under different modalities, eight out of 45 (17.8%) polyps yielded discordant interpretations and the possibility of incorrect diagnoses was highest with the TE-colon mode.
Conclusion: The use of high definition endoscopy combined with i-Scan system is satisfactory in predicting the histology of small colon polyps without the need of magnification. This advantage is mostly related to the pit-pattern enhancement.
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