Computer assisted endoscopic measurement for area of gastric lesions / 中华消化内镜杂志

ABSTRACT

Objective To explore an accurate,objective and simple method for barrel distortion correction and lesion area measurement by assistance of computer.Methods The software of Panaroma tool was employed to correct barrel distortion of endoscopy and Image J to measure lesion size and manage the relative measurement error.Computed measurement in vitro of lesion area was established,firstly,by identification of correction factor of Panorama tool to minimize measurement error; then by determination of influence of object distance change between the lens and the image.This measurement was used on patients with gastric ulcer for focal area.Results were compared with those of traditional method.Results Number of 0.1was determined to be the correction factor for barrel distortion of endoscopy.Prior to the correction of the barrel distortion,the relative error of measurement gradually increased with the increasing distance between endoscopy and the image.However,different object distances did not exert influence on the relative measurement error when barrel distortion was corrected by Panaroma tool ( P =0.141 ).A total of 50 foci of gastric ulcer were measured,results from combinational treatment of Panorama tool and Image J showed the areas (35.0 ± 5.0) mm2 were significantly larger than those determined by traditional method [ ( 29.1 ± 4.1 ) mm2,P =0.000 ],with a correlation coefficient of 0.988.Conclusion Computed endoscopic lesion measurement is a relatively accurate,objective and simple method to determine the area of gastric lesions.