Sensitivity of the suspected blood indicator: an experimental study.
OBJECTIVE
To investigate whether suspected blood indicator (SBI) in capsule endoscopy (CE) is affected by background color and capsule passage velocity.


METHODS
Experimental models of the small intestine constructed from paper in a variety of colors were used to simulate the background colors observed in CE images. The background colors studied included very pale yellow, yellow, very pale magenta, light grayish pink, burnt sienna, and deep and dark brown, and red spots were attached inside them. An endoscopic capsule was manually passed through the models. The rate of detection of the red spots by the SBI was evaluated based on the colors of the models and the capsule passage velocities (0.5 cm/s, 1 cm/s, and 2 cm/s).


RESULTS
The rate of detection of the red spots by the SBI differed significantly according to the background color of the model (P < 0.001). Detection rates were highest for backgrounds of very pale magenta, burnt sienna, and yellow, in that order. They were lowest for backgrounds of dark brown and very pale yellow. The rate of detection of red spots by the SBI tended to decrease at rapid capsule passage velocities (1-2 cm/s) compared to slow velocities (0.5 cm/s) for backgrounds of very pale yellow (P = 0.042), yellow (P = 0.001), very pale magenta (P = 0.002), and burnt sienna (P = 0.001). No significant differences in the rate of detection were observed according to velocity for light grayish pink (P = 0.643) or dark brown (P = 0.396).


CONCLUSIONS
SBI sensitivity was affected by background color and capsule passage velocity in the models. These findings may facilitate the rapid detection of bleeding lesions by CE.
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon 200-722, South Korea.
Sung Chul
SC
Park
Hoon Jai
HJ
Chun
Eun Sun
ES
Kim
Bora
B
Keum
Yeon Seok
YS
Seo
Yong Sik
YS
Kim
Yoon Tae
YT
Jeen
Hong Sik
HS
Lee
Soon Ho
SH
Um
Chang Duck
CD
Kim
Ho Sang
HS
Ryu
D053704:Capsule Endoscopy / Q000379:methods*; D003116:Color; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007421:Intestine, Small / Q000473:pathology*; D008954:Models, Biological; D012680:Sensitivity and Specificity