Department of Electrical and Computer Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada.
World J Gastroenterol. 2012 Aug 28;18(32):4270-7. doi: 10.3748/wjg.v18.i32.4270.
To investigate the performance of a new software-based colonoscopy quality assessment system.
The software-based system employs a novel image processing algorithm which detects the levels of image clarity, withdrawal velocity, and level of the bowel preparation in a real-time fashion from live video signal. Threshold levels of image blurriness and the withdrawal velocity below which the visualization could be considered adequate have initially been determined arbitrarily by review of sample colonoscopy videos by two experienced endoscopists. Subsequently, an overall colonoscopy quality rating was computed based on the percentage of the withdrawal time with adequate visualization (scored 1-5; 1, when the percentage was 1%-20%; 2, when the percentage was 21%-40%, etc.). In order to test the proposed velocity and blurriness thresholds, screening colonoscopy withdrawal videos from a specialized ambulatory colon cancer screening center were collected, automatically processed and rated. Quality ratings on the withdrawal were compared to the insertion in the same patients. Then, 3 experienced endoscopists reviewed the collected videos in a blinded fashion and rated the overall quality of each withdrawal (scored 1-5; 1, poor; 3, average; 5, excellent) based on 3 major aspects: image quality, colon preparation, and withdrawal velocity. The automated quality ratings were compared to the averaged endoscopist quality ratings using Spearman correlation coefficient.
Fourteen screening colonoscopies were assessed. Adenomatous polyps were detected in 4/14 (29%) of the collected colonoscopy video samples. As a proof of concept, the Colometer software rated colonoscope withdrawal as having better visualization than the insertion in the 10 videos which did not have any polyps (average percent time with adequate visualization: 79% ± 5% for withdrawal and 50% ± 14% for insertion, P < 0.01). Withdrawal times during which no polyps were removed ranged from 4-12 min. The median quality rating from the automated system and the reviewers was 3.45 [interquartile range (IQR), 3.1-3.68] and 3.00 (IQR, 2.33-3.67) respectively for all colonoscopy video samples. The automated rating revealed a strong correlation with the reviewer's rating (ρ coefficient= 0.65, P = 0.01). There was good correlation of the automated overall quality rating and the mean endoscopist withdrawal speed rating (Spearman r coefficient= 0.59, P = 0.03). There was no correlation of automated overall quality rating with mean endoscopists image quality rating (Spearman r coefficient= 0.41, P = 0.15).
The results from a novel automated real-time colonoscopy quality feedback system strongly agreed with the endoscopists' quality assessments. Further study is required to validate this approach.
研究一种新的基于软件的结肠镜质量评估系统的性能。
该基于软件的系统采用了一种新颖的图像处理算法,可实时从实时视频信号中检测图像清晰度、退出速度和肠道准备水平。图像模糊和退出速度的阈值最初是通过两位经验丰富的内镜医生审查样本结肠镜视频任意确定的。随后,根据有足够可视化的退出时间百分比(评分 1-5;1 时百分比为 1%-20%;2 时百分比为 21%-40%,依此类推)计算总体结肠镜质量评分。为了测试建议的速度和模糊阈值,从专门的门诊结肠癌筛查中心收集了筛查结肠镜退出视频,进行自动处理和评分。将退出质量评分与同一患者的插入进行比较。然后,3 位经验丰富的内镜医生以盲法方式查看收集的视频,并根据 3 个主要方面(图像质量、肠道准备和退出速度)对每个退出的整体质量(评分 1-5;1 为差;3 为平均;5 为优秀)进行评分。使用 Spearman 相关系数比较自动质量评分和平均内镜医生质量评分。
评估了 14 例筛查性结肠镜检查。在收集的结肠镜视频样本中,4/14(29%)发现了腺瘤性息肉。作为概念验证,Colometer 软件对结肠镜退出的评估显示,在没有任何息肉的 10 个视频中,可视化效果更好(平均有足够可视化的时间百分比:退出时为 79%±5%,插入时为 50%±14%,P<0.01)。未切除息肉的退出时间为 4-12 分钟。自动系统和审查者的中位数质量评分分别为 3.45(四分位距,3.1-3.68)和 3.00(四分位距,2.33-3.67),用于所有结肠镜视频样本。自动评分与审查者的评分具有很强的相关性(ρ系数=0.65,P=0.01)。自动整体质量评分与内镜医生平均退出速度评分呈良好相关性(Spearman r 系数=0.59,P=0.03)。自动整体质量评分与内镜医生的图像质量评分无相关性(Spearman r 系数=0.41,P=0.15)。
一种新的基于软件的实时结肠镜质量反馈系统的结果与内镜医生的质量评估高度一致。需要进一步研究来验证这种方法。