Bayley R, Carothers A, Chen X, Farrow S, Gordon J, Ji L, Piper J, Rutovitz D, Stark M, Wald N
MRC Human Genetics Unit, Western General Hospital, Edinburgh, Great Britain.
Mutat Res. 1991 Dec;253(3):223-35. doi: 10.1016/0165-1161(91)90135-u.
A system for scoring dicentric chromosomes by image analysis comprised fully automatic location of mitotic cells, automatic retrieval, focus and digitization at high resolution, automatic rejection of nuclei and debris and detection and segmentation of chromosome clusters, automatic centromere location, and subsequent rapid interactive visual review of potential dicentric chromosomes to confirm positives and reject false positives. A calibration set of about 15,000 cells was used to establish the quadratic dose response for 60Co gamma-irradiation. The dose-response function parameters were established by a maximum likelihood technique, and confidence limits in the dose response and in the corresponding inverse curve, of estimated dose for observed dicentric frequency, were established by Monte Carlo techniques. The system was validated in a blind trial by analysing a test set comprising a total of about 8000 cells irradiated to 1 of 10 dose levels, and estimating the doses from the observed dicentric frequency. There was a close correspondence between the estimated and true doses. The overall sensitivity of the system in terms of the proportion of the total population of dicentrics present in the cells analysed that were detected by the system was measured to be about 40%. This implies that about 2.5 times more cells must be analysed by machine than by visual analysis. Taking this factor into account, the measured review time and false positive rates imply that analysis by the system of sufficient cells to provide the equivalent of a visual analysis of 500 cells would require about 1 h for operator review.
一种通过图像分析对双着丝粒染色体进行评分的系统，包括有丝分裂细胞的全自动定位、自动检索、聚焦和高分辨率数字化、细胞核和碎片的自动剔除以及染色体簇的检测和分割、着丝粒的自动定位，以及随后对潜在双着丝粒染色体进行快速交互式视觉检查以确认阳性并排除假阳性。使用一组约15,000个细胞的校准集来建立60Coγ射线照射的二次剂量响应。剂量响应函数参数通过最大似然技术确定，并且通过蒙特卡罗技术确定剂量响应以及观察到的双着丝粒频率的估计剂量的相应反曲线上的置信限。该系统在一项盲法试验中得到验证，通过分析一个测试集，该测试集包含总共约8000个细胞，照射到10个剂量水平中的1个，并根据观察到的双着丝粒频率估计剂量。估计剂量与真实剂量之间存在密切对应关系。该系统的总体灵敏度，以分析的细胞中存在的双着丝粒总数中被系统检测到的比例来衡量，约为40%。这意味着通过机器分析的细胞数量必须比视觉分析多约2.5倍。考虑到这个因素，测量的检查时间和假阳性率表明，通过系统分析足够数量的细胞以提供相当于对500个细胞进行视觉分析的结果，操作员检查大约需要1小时。
