2. Introduction
● Can we ignore diminutive distal colon hyperplastic polyps?
○ Vleugels JLA, Hazewinkel Y, Fockens P, Dekker E. Natural history of
diminutive and small colorectal polyps: a systematic literature review.
Gastrointest Endosc. 2017;85(6):1169-1176.e1.
● Distinguish adenoma (especially sessile serrated adenoma) / hyperplastic
polyps is difficult.
Short, Matthew W., et al. "Colorectal cancer screening and surveillance." American family physician 91.2 (2015).
3. NBI International Colorectal Endoscopic classification
Utsumi T, Iwatate M, Sano W,
et al. Polyp Detection,
Characterization, and
Management Using Narrow-
Band Imaging with/without
Magnification. Clin Endosc.
2015;48(6):491-7.
4. WASP classification system
Vleugels JL, Ijspeert
JE, Dekker E. Serrated
lesions of the colon
and rectum: the role
of advanced
endoscopic imaging.
Best Pract Res Clin
Gastroenterol.
2015;29(4):675-86.
5. Methods: obtaining of videos
Olympus
190 Series
Far focus
mode
Near focus
mode
Resected &
retrieved
NICE
Classification
9. Methods: dataset size
● The training, validation, and final testing sets of endoscopic videos of polyps
had no overlaps.
● Training set: 223 polyp videos: 29% NICE type I, 53% type II, 18% normal
mucosa
○ Comprising 60080 frames
● Validation set: 40 polyp videos
11. Result: the final testing set
● The final test set: 125 consecutively
identified diminutive polyps
○ 51 hyperplastic polyps
○ 74 adenomas
158 consecutive
diminutive polyps
3: SSP
25: normal or lymphoid tissue
2: faecal material
1: corrupted
2: multiple polyps in one frame
125 polyps for final
testing dataset
12. Result: the high confidence prediction
● Only 106 polypes was labeled as “high confidence”.
● Accuracy of the model was 94% (95% CI: 86% - 97%)
● Adenoma: sensitivity 98% (95% CI: 92% ~ 100%); negative predictive value: 97%
specificity 83%(95% CI 67% ~ 93%); positive predictive value: 90%
15. Discussion
Abu dayyeh BK, Thosani N,
Konda V, et al. ASGE
Technology Committee
systematic review and meta-
analysis assessing the ASGE
PIVI thresholds for adopting
real-time endoscopic
assessment of the histology of
diminutive colorectal polyps.
Gastrointest Endosc.
2015;81(3):502.e1-502.e16.
16. Discussion
● Real time recognition: 50 ms
● Previous studies have used magnifying colonoscopes or endocytoscopy,
both of which are rarely available in the USA or Europe.
● Limitation
○ The collection of the videos was done by a single operator.
○ The videos was not collected for this (CADx) purpose, therefore, some
polyps may be blur or partial presented in the videos.
● This algorithm was not optimised for sessile serrated adenoma.
credibility(t)=alpha * credibility(t−1) + (1−alpha) * update(t)
update(t) is an indication of whether the model’s predictions have changed between frames at t−1 and t
alpha is a parameter between 0 and 1 that is found by searching over a validation set