Biomedical subjects

A Doudkine

Publications and source records attributed to A Doudkine.

7 recordsLinked to original sources

PubMed2001

Nuclear texture features for classifying benign vs. dysplastic or malignant squamous epithelium of the larynx.

OBJECTIVE: To search for nuclear features and feature combinations able to assess malignancy and premalignant changes on tissue sections of laryngeal squamous epithelium. STUDY DESIGN: A total of 139 lesions of benign changes (BC) (n = 44), epithelial dysplasias (ED) (n = 50) and invasive laryngeal cancer (LC) (n = 45) were retrieved from archival pathology specimens. The goal of this study was to identify the best features or feature combinations that discriminate BC from LC and also reflect the degree of ED. In order to verify the results on independent data, the groups were split into two separate subgroups, one for training and one for testing. RESULTS: On the test set of slides, the overall correct classification of BC vs. LC cases was 82% using only one feature, fractal2_area. This classification rate could be increased to 91% when a discriminant function based on 10 features was used. However, this gain was not significant. CONCLUSION: Fractal texture features can be used to assess malignancy on tissue sections as an alternative to DNA measurement. In this study feature combinations did not significantly improve classification rates.

Archives↗

PubMed2000

Specific changes of chromatin structure in nuclei of normal epithelium adjacent to laryngeal squamous cell carcinoma. A preliminary study of 82 cases.

The aim of this study was to confirm the existence of specific nuclear texture feature alterations of histologically normal epithelial borders nearby invasive laryngeal cancer (NC). Paraffin sections of NC and of chronic inflammations unrelated to cancer (CI) were analysed for nuclear texture and for integrated optical density (IOD-index) and were compared to normal epithelium of patients without evidence of cancer (NE). Several discriminant functions based on nuclear texture features were trained to separate different subgroups. As the most important result, specific nuclear texture feature shifts were only found in NC with high-density lymphocytic stroma infiltrate (NC+). Classification of nuclei of NE versus NC+ was correct in 70%. The same classifier was correct in only 58% when nuclei of NE were classified versus CI. We also found lower values of IOD-Index within the NC+ group when compared to NE (p < 0.001).

Carcinoma, Squamous Cell↗

PubMed1998

The effect of primary fixation with standard postfixation and the duration of hydrolysis on nuclear features in image cytometry.

The effect of three primary fixation procedures, used in the preparation of routine cytological samples: air-drying, Delaunay, and Saccomanno fixation, with postfixation in modified Böhm-Sprenger fixative, on nuclear features as a function of hydrolysis time is reported. Three different cell types: lymphatic cells (tonsil), epithelial cells (buccal mucosa) and mesenchymal cells (uterine myometrium) were used for the study. Our findings show, that generally not all features have the same plateau times as the IOD (integrated optical density), and that many features show different values depending on cell type and fixation method. It is therefore recommended that for any primary fixative used in routine clinical work and for each cell type, the hydrolysis curve for all nuclear features to be used in sample analysis should be established.

Analysis of Variance↗

PubMed1997

Sputum screening by quantitative microscopy: a reexamination of a portion of the National Cancer Institute Cooperative Early Lung Cancer Study.

OBJECTIVE: To investigate the hypothesis that image cytometry of sputum specimens can detect squamous carcinoma without requiring visually abnormal cells. DESIGN: The sensitivity and specificity of image cytometry were evaluated in a case-control study. MATERIAL AND METHODS: Seventy-three sputum slides from the Mayo portion of the National Cancer Institute Cooperative Early Lung Cancer Study were restained by a modified Feulgen method. We examined 40 slides from 9 patients in whom squamous carcinoma developed and 33 slides from 11 patients in whom no cancer developed during a follow-up of at least 5 years. Images of normal epithelial nuclei were collected by using an automated image cytometer. Discriminant analysis was used to determine differences in DNA distribution of normal nuclei in sputum specimens from noncancer patients versus normal nuclei in sputum samples from patients in whom carcinoma developed. RESULTS: By using features based on DNA distribution, 74% correct classification of nuclei was possible without human review of the material and without the use of visually abnormal nuclei. A receiver operating characteristic curve demonstrated sensitivities and specificities, including 40% sensitivity and 90% specificity. CONCLUSION: Although this study was limited to 20-year-old slides and squamous cell carcinoma, automated image cytometry detected a substantial proportion of patients with squamous cell cancer without using visually abnormal nuclei.

Aged↗

PubMed1995

Histometric texture analysis of DNA in thin sections from breast biopsies. Application to the detection of malignancy-associated changes in carcinoma in situ.

OBJECTIVE: To evaluate histometric measurement of nuclear texture in breast biopsy sections in order to detect malignancy-associated changes in apparently normal tissue in the vicinity of carcinoma in situ. STUDY DESIGN: We previously showed that image cytometry measurements of nuclear features--foremost, texture features, describing the organization of Feulgenstained DNA in the cell--can be used to distinguish normal-appearing, diploid epithelial cells from patients with invasive carcinoma of the breast from those with benign biopsies. In that study, referred to as the "single cell analysis," images of at least 200 epithelial cells were acquired for each slide, and substantial user interaction was required to segment cells from each field. Location of isolated cells and interactive segmentation are both time-consuming procedures, particularly in breast tissue, where nuclei can be tightly clustered within a duct. With histometric texture analysis on the same specimens, segmentation of individual cells was ignored, and texture measurements were performed over the entire cluster of relevant cells. With this approach, ploidy information is not available, and touching and overlapping nuclei are included in the measurements. Measurement of histometric texture properties requires substantially less time (at least an order of magnitude) than individual cell measurement and, if ploidy information is not significant, may therefore provide a more practical means of analysis for tissue sections. RESULTS: Seventeen cases of invasive carcinoma and 17 cases of nonproliferative breast disease were examined. Using stepwise discriminant function analysis, slides were classified into one of the two groups with an accuracy of 88.6% in the case of single cell analysis and with an accuracy of 88.2% using histometric analysis. CONCLUSION: The existence of malignancy-associated changes in the breast was confirmed by an independent analysis of the same specimens. Although the two methods are not directly comparable, we found that histometric texture analysis performs at least as well as single-cell analysis for the detection of malignancy-associated changes in breast carcinoma.

Biopsy↗

PubMed1995

Malignancy associated changes in cervical smears: systematic changes in cytometric features with the grade of dysplasia.

For almost ten years. Malignancy Associated Changes have been consistently found by means of high resolution image analysis of apparently normal uterine cervix cells. The study was performed on normal intermediate cells randomly selected from 1850 cervical smear slides classified as negative, mild dysplasia, moderate dysplasia and severe dysplasia. Size and texture features, performed by the Cyto-Savant software, have shown significant monotonic changes with the grade of dysplasia. These findings indicate that the intensity of Malignancy Associated Changes are directly related to the severity of the adjacent lesions.

Cell Transformation, Neoplastic↗

PubMed1995

Nuclear texture measurements in image cytometry.

DNA image cytometry is widely used in cytopathology as a means to obtain objective information concerning the diagnosis and prognosis of human cancer. Using specially designed devices, the high resolution spatial and photometric information is available in the images of a microscopic field. If quantitative DNA specific stains are used the chromatin distribution in the cell nuclei can be measured, which is one of the critical features for cytopathological analysis. In normal cells, changes in the chromatin appearance reflect changes in the activation patterns of genes. In tumors, dramatic changes in the nuclear chromatin appearance are common and have been associated with the progression of the disease. Features describing the chromatin distribution pattern are referred to as texture features. Nuclear texture features are sensitive to the differences between the various descriptive classes of chromatin patterns. In this paper we discuss the main categories of nuclear texture measurements. Texture features can be roughly divided into the following categories: 1) descriptive statistics of chromatin distribution; 2) discrete texture features; 3) range extreme; 4) markovian; 5) run length and 6) fractal texture features. Representative features of each of the above categories are discussed together with mathematical formulas, simple figures for explanation as well as images of typical cells which differ significantly in some texture features. Key references are also provided.

Cell Nucleus↗