Evaluation of a metaphase chromosome finder: potential application to chromosome-based radiation dosimetry.
An automated metaphase chromosome finder is described which combines a microscope, state-of-the-art computer technology and a simple decision-making algorithm. A microscope slide is systematically scanned under computer control and the location of each positive 'signal' placed into memory for later recall and review by a human operator. The software identifies two events, positives (the presence of a 'signal') and negatives (the absence of a 'signal'). The performance of the metaphase finder was evaluated using receiver operating characteristic curve analysis. At the optimum decision threshold, the detection rates for true positives (metaphase spreads) was about 74%, false positives (type I error) about 6%, and false negatives (type II error) about 26%. The overall accuracy, which accounts for differences in the sensitivity of the detector to positive and negative events, was 89.4% (+/- 0.01%; standard error of the mean, n = 8). Potential applications to radiation dosimetry are discussed.
McLean
J R
JR
Health Canada, Radiation Protection Bureau, Ottawa, Canada.
Johnson
F
F
D000465:Algorithms; D001800:Blood Specimen Collection; D002877:Chromosomes, Human / Q000528:radiation effects; D003201:Computers; D003582:Cytogenetics / Q000295:instrumentation*; D003662:Decision Theory; D005189:False Positive Reactions; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008328:Man-Machine Systems; D008677:Metaphase; D012372:ROC Curve; D011829:Radiation Dosage; D012984:Software