M. Haucke

Computer analysis of chromatin arrangement and nuclear texture in follicular thyroid tumours

SummaryThe differentiation of the thyroid glands follicular neoplasias into adenomas and carcinomas is currently done using the histological criteria recommended by WHO. This pilot study of 10 human follicular carcinomas and 10 folliculars adenomas demonstrates the possibility of a cytological classification using digital picture processing of high resolution cell images. Giemsa stained paraplast sections were scanned with a Colour-TV-camera, different channels were used with respect to staining and analyzing methods and computed with an image processing system. The computer aided cytophotometric methods detected significant differences in the chromatin arrangement and structure.

Automated quantitative analysis of single and double label autoradiographs.

A method for the analysis of silver grain content in both single and double label autoradiographs is presented. The total grain area is calculated by counting the number of pixels at which the recorded light intensity in transmission dark field illumination exceeds a selected threshold. The calibration tests included autoradiographs with low (3H-thymidin) and high (3H-desoxyuridin) silver grain density. The results are proportional to the customary visual grain count. For the range of visibly countable grain densities in single labeled specimens, the correlation coefficient between the computed values and the visual grain counts is better than 0.96. In the first emulsion of the two emulsion layer autoradiographs of double labeled specimens (3H-14C-thymidin) the correlation coefficient is 0.919 and 0.906. The method provides a statistical correction for the background grains not due to the isotope. The possibility to record 14C tracks by shifting the focus through the second emulsion of the double labeled specimens is also demonstrated. The reported technique is essentially independent of size, shape and density of the grains.

Computer aided analysis of chromatin network and basophil color for differentiation of mononuclear peripheral blood cells.

Computer aided differentiation of plasmoblasts, Pfeiffer cells, immunoblasts, lymphocytes and centrocytes is achieved with the parameters of chromatin network arrangement and structure, and multispectral cytoplasm color. The digital methods involve: (a) segmenting the nuclear image into topographic sections and analyzing the optical density distribution from the chromatin in these sections; (b) determining the nuclear structure with a 7 x 7 median filter, gradient filter and contour following algorithms; and (c) clustering two-dimensional chromatic data from panoptically stained cellular components. The parameters reported here are a subset of those needed for the automated diagnosis of many hematologic diseases especially the leukemias.

Statistical evaluation of computer markers to detect leukemias

Abstract In a first clinical test, computer programs are being used to diagnose leukemias. The data set includes 20 000 cells from 120 different blood samples taken from 80 patients suffering from various hematological disorders. BMDP7M and CART statistical software test the classification power of the cell markers extracted by image processing. The feature distributions from the mononuclear cell population correlate directly to the specific leukemia. The computer methods and results presented here are part of an investigation to develop, refine and test computer aided methods in the diagnosis of blood malignancies. The data suggest the possibility of new diagnostic procedures in hematology.

A preprocessing method for the contrast enhancement of tv-scanned electron microscopic images

Abstract Preprocessing TV-scanned images in transmission electron microscopy improves the results of subsequent digital contrast enhancement. The method takes into account noise, system artifacts and the image forming modes of darkfield and brightfield.

Computer Color Vision

The application of color television technology to computer color perception and image processing is demonstrated using photographic color control patches and gray scales.

Computer-Aided Diagnosis Of Leukemic Blood Cells

In a first clinical test, computer programs are being used to diagnose leukemias. The data collected include blood samples from patients suffering from acute myelomonocytic-, acute monocytic- and acute promyelocytic, myeloblastic, prolymphocytic, chronic lymphocytic leukemias and leukemic transformed immunocytoma. The proper differentiation of the leukemic cells is essential because the therapy depends on the type of leukemia. The algorithms analyse the fine chromatin texture and distribution in the nuclei as well as size and shape parameters from the cells and nuclei. Cells with similar nuclei from different leukemias can be distinguished from each other by analyzing the cell cytoplasm images. Recognition of these subtle differences in the cells require an image sampling rate of 15-30 pixel/micron. The results for the entire data set correlate directly to established hematological parameters and support the previously published initial training set .

Computeranalysen zur Leukämiefrüherkennung

Die starkste Herausforderung fur die computergestutzte Bildanalyse von Leukozyten im routinemasig gefarbten Blutausstrich stellen die mononuklearen Blutzellen, insbesondere die unreifsten Zellformen, dar. Wahrend fur die Trennung der vorkommenden segment- und rundkernigen Blutzellen relativ einfache morphologische Kriterien wie Zell- und Kern- grose oder -form, Kern-Plasmarelation oder einfache Farbkriterien ausreichen, werden fur die direkte Blastzellerkennung wesentlich feinere Strukturanalysen an Zellkern und Zytoplasma sowie bessere Farbanalysen benotigt. Es wird ein Zwischenergebnis aus einem laufenden Projekt zur Leukamiefruherkennung dargestellt, bei dem eine bisher nicht erreichte Zellzahl und Zellvielfalt analysiert wurde (1).

Automatisierte Chromosomenanalyse Mittels eines Hochauflösenden TV-Mikroskops

Seit Jahren bemuhen sich verschiedene Arbeitsgruppen, die Arbeit im genetischen Labor durch eine zytophotometrische Erfassung der Metaphasen und ihre anschliesende Auswertung durch den Rechner zu unterstutzen. In dieser Arbeit wird nun ein Bildverarbeitungssystem beschrieben, das mit Hilfe der beiden Parameter “Chromosomengrose” und “ Zentromer index” ungebanderte Chromosomen einer Metaphase automatisch zu einem Karyotyp anordnet. Es dient im Moment als Basis fur ein Programmsystem, das die Sequenz der Zentromerteilung bei den Chromosomen von Muntjak Zellen bestimmt /3/.

Computeranalyse von Elektronenmikroskopischen Bildern

Bislang war die Bildqualitat bei der TV-Ubertragung vom Transmissionselektronenmikroskop (TEM) sehr mangelhaft. Niedrige Lichtenergie aus dem TEM, fehlende Empfindlichkeit und Rauschen im Bildempfanger waren die Hauptschwierigkeiten. Die Bearbeitung der elektronenmikroskopischen Bilder erfolgte deshalb vorwiegend auf photometrischem Wege an Mikrografien oder uber Eingaben auf ein Digitalisiertablett interaktiver Bildanalysesysteme an aus dem TEM herausgespiegelten Bildern. Erst in jungster Zeit ist mit der Entwicklung hochempfindlicher Kameras, schneller Analog-Digital Wandler und groserer Laborrechnerkapazitat eine direkte Bilderfassung uberhaupt moglich geworden.