Evaluation of 4 three-dimensional representation algorithms in capsule endoscopy images

摘要

AIM:To evaluate the three-dimensional(3-D)representation performance of 4 publicly available Shapefrom-Shading(SfS)algorithms in small-bowel capsule endoscopy(SBCE).METHODS:SfS techniques recover the shape of objects using the gradual variation of shading.There are4 publicly available SfS algorithms.To the best of our knowledge,no comparative study with images obtained during clinical SBCE has been performed to date.Three experienced reviewers were asked to evaluate 54 twodimensional(2-D)images(categories:protrusion/inflammation/vascular)transformed to 3-D by the aforementioned SfS 3-D algorithms.The best algorithm was selected and inter-rater agreement was calculated.RESULTS:Four publicly available SfS algorithms were compared.Tsai’s SfS algorithm outperformed the rest(selected as best performing in 45/54 SBCE images),followed by Ciuti’s algorithm(best performing in 7/54images)and Torre o’s(in 1/54 images).In 26/54 images;Tsai’s algorithm was unanimously selected as the best performing 3-D representation SfS software.Tsai’s 3-D algorithm superiority was independent of lesion category(protrusion/inflammatory/vascular;P=0.678)and/or CE system used to obtain the 2-D images(MiroCam/PillCam;P=0.558).Lastly,the interobserver agreement was good(kappa=0.55).CONCLUSION:3-D representation software offers a plausible alternative for 3-D representation of conventional capsule endoscopy images(until optics technology matures enough to allow hardware enabled-"real"3-D reconstruction of the gastrointestinal tract).