PubMed · 8832824
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W D Rees. 1996. DNA sequencing.. https://doi.org/10.1079/pns19960054
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In this paper, wavelets were employed for multi-scale image analysis to extract parameters for the description of chromatin texture in the cytological diagnosis and grading of invasive breast cancer. Their value was estimated by comparing the performance of co-occurrence, densitometric, and morphometric parameters in an automated K-nearest neighbor (Knn) classification scheme based on light microscopic images of isolated nuclei of paraffin-embedded tissue. This design allowed a multifaceted cytological retrospective study of which the practical value can be judged easily. Results show that wavelets perform excellently with classification scores comparable with densitometric and co-occurrence features. Moreover, because wavelets showed a high additive value with the other textural groups, this panel allowed a very profound description with higher recognition scores than previously reported (76% for individual nuclei, 100% for cases). Morphometric parameters performed less well and only slightly increased correct classification. The major drawback, besides image segmentation errors demanding operator supervision, emanated to be the few false-negative cases, which restrict the immediate practical use. However, an enlargement of the parameter set may avoid this misclassification, resulting in an applicable expert system of practical use.
Applications of fluorescence in situ hybridization (FISH) for translocation studies and biological dosimetry would benefit substantially from reliable and efficient automatic detection of metaphase chromosomes labeled with fluorescent dyes. We replicated and evaluated a fluorescence metaphase finder previously developed at the Medical Research Council (MRC), Human Genetics Unit (Scotland) and at Lawrence Berkeley Laboratory (LBL; California). The MRC/LBL system seemed to detect nearly all of the metaphases on the test slides, but it presented an unacceptable number of false positives (about five false positives per one true positive). Furthermore, we determined that the system actually overcalled true detections by counting certain metaphase spreads twice (duplicates). Through modifications of the MRC/LBL system, we developed the Lawrence Livermore National Laboratory (LLNL) system, which minimizes the detection of duplicates, incorporates new detection features, uses a binary decision tree (BDT) for classification, and provides functionalities to improve scanning accuracy and improve the post-detection review. To test the new system, DAPI-stained preparations of metaphase chromosomes from blood lymphocytes of four unrelated donors were placed on slides in drops ranging from 7 mm to 20 mm in diameter. Drops contained between 5 and 200 scorable metaphases each. The LLNL system achieved approximately 90% detection of non-duplicated metaphases as verified by an expert cytogeneticist, with typically less than one false positive per every one true positive detected.
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