Background and study aims: The resolution of endoscopes has increased in recent years. Modern Fujinon colonoscopes
have a charge-coupled device (CCD) pixel density of 650000 pixels compared with the
410000 pixel CCD in standard-definition scopes. Acquiring high-definition scopes represents
a significant capital investment and their clinical value remains uncertain. The aim
of the current study was to investigate the impact of high-definition endoscopes on
the in vivo histology prediction of colonic polyps.
Patients and methods: Colonoscopy procedures were performed using Fujinon colonoscopes and EPX-4400 processor.
Procedures were randomized to be performed using either a standard-definition EC-530
colonoscope or high-definition EC-530 and EC-590 colonoscopes. Polyps of < 10 mm were
assessed using both white light imaging (WLI) and flexible spectral imaging color
enhancement (FICE), and the predicted diagnosis was recorded. Polyps were removed
and sent for histological analysis by a pathologist who was blinded to the endoscopic
diagnosis. The predicted diagnosis was compared with the histology to calculate the
accuracy, sensitivity, and specificity of in vivo assessment using either standard-
or high-definition scopes.
Results: A total of 293 polyps of < 10 mm were examined – 150 polyps using the standard-definition
colonoscope and 143 polyps using high-definition colonoscopes. There was no difference
in sensitivity, specificity or accuracy between the two scopes when WLI was used (standard
vs. high: accuracy 70 % [95 %CI 62 – 77] vs. 73 % [95 %CI 65 – 80]; P = 0.61). When FICE was used, high-definition colonoscopes showed a sensitivity of
93 % compared with 83 % for standard-definition colonoscopes (P = 0.048); specificity was 81 % and 82 %, respectively.
Conclusions: There was no difference between high- and standard-definition colonoscopes when white
light was used, but FICE significantly improved the in vivo diagnosis of small polyps
when high-definition scopes were used compared with standard definition.
