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1

Quantitative tests-based assessment of biomedical image enhancement procedures

Przytulska M., Kulikowski J. L.

Biocybernetics and Biomedical Engineering

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2016

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Vol. 36, no. 1

205--216

EN

This paper describes a novel method of images enhancement procedures evaluation. A necessity of such method follows from the fact that the results of morphological or statistical image analysis in medical and/or technological applications strongly depend on the effectiveness of image preprocessing. The proposed method is based on standard images called testing sets composed of several basic patterns. Filtered testing sets are compared to basic patterns and the averaged distances between them are used as primary filtering quality scores. Then, they are used to calculation of several secondary parameters called image restoration errors. The image restoration errors make possible separate characterization of filters' ability to improve image contrast, discrimination of small details or neglect the influence of image parallel shifts on the visibility of image details. Practical application of the proposed method is illustrated by example of comparison of the quality of three exemplary filters: a one based on second-level morphological spectra, Laplace and Sobel, filters. Similar comparison has been performed on the same filters combined with image binary thresholding procedures. At last, the numerical evaluation is compared to visual filters evaluation based on the results of NMR brain image enhancement reached by using different filtering methods.

2

Computer-aided image analysis for microcapsules' quality assessment

Przytulska M., Kulikowski J. L., Lewińska D., Grzeczkowicz M., Kupikowska-Stobba B.

Biocybernetics and Biomedical Engineering

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2015

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Vol. 35, no. 4

342--350

EN

Application of computer-aided image analysis to quality assessment of inner structure of alginate-polyethersulfone microcapsule is presented. The microcapsules are provided for analysis in the form of optical microscope images of their cross-sections. A specialized computer program APEK makes it possible to measure and calculate a set of morphological parameters describing microcapsules' outer and inner size and shape, as well as the thickness of a polyethersulfone membrane which covers hydrogel microcapsule core. It is described a method of thickness profile of microcapsule's membrane measuring based on skeleton line. Calculations are illustrated by an example. Suggestions concerning future works have been formulated.

3

Biomedical images enhancement based on the properties of morphological spectra

Przytulska M., Kulikowski J. L., Wierzbicka D.

Biocybernetics and Biomedical Engineering

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2015

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Vol. 35, no. 3

206--215

EN

The method enhancing distinctiveness of the micro-morphological structures, developed using the properties of morphological spectra of their monochromatic 2D images, is presented and its effects on the bone section image are statistically compared with enhancements by Sobel, Roberts and Laplace high-pass filters. Comparison of different filters based on statistical parameters of the classes of selected image details is presented. The preferable method for choosing filtering weight coefficients is described and illustrated by an example of processing an electron-microscope image of a biotechnological specimen. The applicability of this approach and possible development directions are discussed.

4

Membranes' porosity evaluation by computer-aided analysis of SEM images – a preliminary study

Chwojnowski A., Przytulska M., Wierzbicka D., Kulikowski J., Wojciechowski C.

Biocybernetics and Biomedical Engineering

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2012

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Vol. 32, no. 4

65-75

EN

The problem of quality control of membranes destined for medical applications is presented. The shape of the membranes surface, its structure, porosity and coarseness are of importance in contact with live cells or simply with live tissue, and as such they should be controlled. For this purpose, scanning electron microscopy (SEM) in our work was used. Results of capillary polysulphone (PSF) 70000 m.m. and polyetherosulphone (PES) 42000 m.m. membranes examination are described. An attempt to apply the computer-aided SEM images processing methods to the membranes' porosity evaluation was made and is presented in the paper. In particular, an approach to segmentation of contours of micropores in the visualized membranes' sections and to evaluation of their morphological parameters is described. An attempt to an approximate statistical reconstruction of 3-dimensional structure of micropores on the basis of collections of 2-dimensional membranes' sections is also described.

5

Discrimination of Poorly Distinguishable Random Textures by Statistical Analysis of Morphological Spectra

Przytulska M., Kulikowski J. L., Wierzbicka D.

Machine Graphics and Vision

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2011

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Vol. 20, No. 4

455-477

EN

The paper describes a method for discrimination of poorly distinguishable textures based on application of morphological spectra. The textures are analyzed as random fields of specific probability distributions. The samples of textures are thus considered as their instances and so are also their morphological spectra. Some basic properties of morphological spectra, as well as the definition of similarity measure are shortly reminded. The problem of textures discrimination is formulated as similarity assessment of spectral components histograms. For this purpose, various statistics like: mean value, standard deviation, skewness and kurtosis, as well as some secondary statistics based on theformer, are used. A discriminating index is introduced for evaluation of their discriminating properties. The method of evaluating the discriminating power of statistics based on 1st and 2nd level morphological spectra is illustrated by analysis of the spectra of USG liver images in the groups of healthy persons and patients affected by liver fibrosis. A short description of a IASS program used to the calculations is given. The problem of textures discrimination invariant to rotations and parallel translations of images is described. It is shown that the proposed method discriminates statistically the “ill” and “healthy” textures despite the fact that the differences between them are visually not distinguishable.

6

Discrimination of biomedical textures based on logical similarity measure

Kulikowski J. L., Przytulska M., Wierzbicka D.

Journal of Medical Informatics & Technologies

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2011

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Vol. 17

89--95

EN

The paper presents an approach to discrimination of textures in radiological images based on multi-aspect similarity measures composed of logical tests. There are formulated basis assumptions for similarity measures which can be composed by products of partial (single-aspect) similarity measures. On the basis of similarity measures -similarity classes are defined. Next, two types: strong and weak similarity measures are defined. It is shown that they make possible to define similarity measures based on quality objects properties as well as on their numerical parameters. As an example of application of the general concept discrimination of normal and ill (lesions affected) tissues is considered. It is illustrated by analysis of USG images of liver tissues for which morphological spectra and their statistical parameters have been calculated. It is shown that the differences between values of some pairs of corresponding parameters can be used to a construction of an effective algorithm of textures discrimination. This algorithm takes into consideration both, numerical features of the texture samples and some qualitative data concerning the patients. Conclusions are formulated at the end of the paper.

7

Quantitative examination of liver tissue ultrasound elastograms

Przytulska M., Gierbliński I., Kulikowski J., Skoczylas K.

Biocybernetics and Biomedical Engineering

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2011

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Vol. 31, no. 4

75-85

EN

Methods of computer-aided statistical analysis of ultrasound elastograms are presented. An approach consisting in initial segmentation of elastograms visualizing low-elasticity segments distribuition in the tissue of an examined biological organ and in statistical analysis of this distribution is described. Satisfactory correlation between the values of same statistics and medical specialists' description of human liver elastograms was observed. The ways of continuation of the works aimed at improvement of the elastograms-based diagnostic methods are suggested.

8

Visual Retrieval of Documents Based on Their Multi-Aspect Utility Assessment

Kulikowski J, Przytulska M.

Machine Graphics and Vision

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2010

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Vol. 19, No. 3

299-320

EN

Differences between textual and visual documents retrieval problems are described. It is shown that retrieval of visual documents in experimental data bases requires assessment of image utility and taking it into consideration. A definition of multi-aspect image usefulness measure is proposed. A multi-aspect measure of similarity of images based on their quantitative and/or qualitative features is also proposed. The general concept is illustrated by examples of using morphological spectra as a source of parameters useful in the assessing similarity of some classes of biomedical images. The basic structure and properties of an Image Analysis and Selection System (IASS) are presented as an example of practical realization of the visual documents retrieval methods.

9

Description of biomedical textures by statistical properties of morphological spectra

Kulikowski J. L., Przytulska M., Wierzbicka D.

Biocybernetics and Biomedical Engineering

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2010

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Vol. 30, no. 3

19-34

EN

A class of mathematical model s of biological textures based on the multi-variable probability distributions of their morphological spectra is described. It is shown that a large class of such distributions can be presented by sufficient statistics consisting of the coefficients of their expansion into the series of multi-variable Hermite polynomials. The sufficient statistics can then be simplified by rejection of higher-order terms. The general concepts of mathematical models construction are illustrated by examples of textures of several biological tissues (aorta walls, liver and blood). The role of statistics based on absolute values of morphological spectral components and of their cross-correlation coefficients is underlined.

10

Comparison of SPECT cerebral images examination methods based on luminance level and morphological spectra evaluation

Przytulska M., Kulikowski J. L., Bajer A., Królicki L.

Biocybernetics and Biomedical Engineering

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2009

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Vol. 29, no. 1

29-42

EN

It is presented a method of SPECT (single-photon emission tomography) cerebral images examination based on morphological spectra. The advantages of the SPECT imaging in early diagnosing of encephalic diseases are emphasized. The detected radiation levels in the SPECT imaging are visualized by luminance levels which give insight into the lesions of cerebral tissue. It is shown that a rough, on luminance level based, examination of the SPECT images can be improved if more sophisticated analytical methods are used. Basic notions and properties of morphological spectra and their applicability as tools for biomedical image analysis are shortly reminded. A simple formula for reversing transformation reconstructing of original image on the basis of a given morphological spectrum is presented. Results of experiments consisting in comparison of the morphological spectra calculated for selected pairs of testing windows in the SPECT cerebral images are shown. It has been shown that the morphological spectra can better suit to an effective comparison of views of the cerebral regions located symmetrically with respect to the brain axis separating the left and right cerebral hemispheres than the averaged luminance level.

11

Comparison of different SPECT images analysis methods for inter-hemispheric asymmetry detection in patients with epileptic symptoms

Olejarczyk E., Przytulska M., Bajera A., Królicki L.

Biocybernetics and Biomedical Engineering

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2008

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Vol. 28, no. 4

33-41

EN

The aim of this work was examination of asymmetries in activity of the left and right cerebral hemispheres as well as localization and contouring of the regions of reduced or increased activity on the basis of single photon emission computed tomography (SPECT) images. The mean and standard deviation of normalized intensities inside the contoured areas of images, entropy based on intensity histograms and Chen's fractal dimension were calculated.

12

Analysis of left cardiac ventricle shape variations based on examination of ultrasound images

Przytulska M.

Machine Graphics and Vision

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2007

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Vol. 16, No. 3/4

275-292

EN

The changes in the shape of the left cardiac ventricle within full heart evolution cycle in norm and in pathology are described using a kinetic model programmed and verified on real clinical data. In the model, information is represented by the so-called shape coefficients. The time series of the shape coefficients as well as of differential and normalized shape coefficients of the left heart ventricle have been obtained experimentally. They are then analyzed using three different approaches: spectral analysis, direct analysis of shape coefficients and direct visualization of contractions. In each of those cases, the aim of the analysis is detection and recognition of various types of abnormalities, as well as evaluation of the distance between the detected pathology and the norm.

13

Examination of left cardiac ventricle's contractility based on spectral analysis of ultrasound imaging

Przytulska M., Kulikowski J. L.

Biocybernetics and Biomedical Engineering

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2007

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Vol. 27, no. 4

17-28

EN

A method of left cardiac ventricle's contractility abnormalities recognition and assessment, based on computer-aided analysis of sequences of ultrasonographic images is presented. The method is based on an analytical model of ventricle's shape time-variations during a single or several heart evolution cycles. An approach to ventricle's contractility abnormalities detection and evaluation based on a concept of spectral analysis of the shape coefficients' time-variations is proposed. The shape coefficients can be obtained by a computer-aided analysis of sequences of ultrasonographic cardiac images. The contraction process is characterized by spectral indicators: the contraction-depth ratio and the smoothness ratio. The results of preliminary testing of the method on clinical data are presented.

14

A method of poorly visible left cardiac ventricle's boundary enhancement

Kulikowski J.K., Przytulska M., Wierzbicka D.

Biocybernetics and Biomedical Engineering

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2000

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Vol. 20, no. 4

21-33

EN

Examination of a left cardiac ventricle's shape and volume belongs to routine methods used in advanced cardiac diagnosis. For this purpose X-ray and/or USG cardiac images are used, not only due to their low cost, but also due to the fact that they make possible an examination of long image series representing the heart contractility process. Unfortunately, the quality of USG images is usually low. There is described here a method of poorly visible left cardiac ventricle's boundary enhancement. It belongs to a class of methods based on a multi-step continuous closed contours formation and fitting principIe. The class of contours under consideration is described by a model equation based on trigonometric series. The basic part of contour restoring algorithm is equivalent to a one of finding a solution of an optimisation problem with non-linear goal function and linear constraints. The constraints make us able to take into account medical indications in problem solving. Finally, some remarks about a possibility of using the method to heart contractility investigation are given.

PL

Badanie kształtu i objętości lewej komory serca należy do rutynowych metod stosowanych w diagnostyce kardiologicznej. Do tego celu używa się rentgenowskich lub ultrasonograficznych zobrazowań serca, zarówno ze względu na ich relatywnie niską cenę, jak i ze względu na to, iż umożliwiają one analizę dłuższych serii obrazów przedstawiających proces kurczliwości serca. Niestety, jakość zobrazowań ultrasonograficznych jest zazwyczaj zła. W artykule przedstawiono metodę wyznaczania słabo widocznych obrysów lewej komory serca. Należy ona do klasy metod opartych na zasadzie wielokrokowego formowania i dopasowywania ciągłego konturu do badanego obrazu. Klasa rozważanych konturów jest opisana przez równanie modelowe w postaci szeregu trygonometrycznego. Podstawowa część algorytmu odtwarzania obrysu jest równoważna procedurze poszukiwania rozwiązania problemu optymalizacyjnego z nieliniową funkcją celu i z liniowymi ograniczeniami. Ograniczenia stwarzają możliwość uwzględnienia w rozwiązaniu wskazówek medycznych. W części końcowej zamieszczono uwagi dotyczące możliwości wykorzystania metody w badaniach kurczliwości lewej komory serca.

15

Mathematical models for computer-aided analysis of heart ventricles. Part 2, Kinetic models

Kulikowski J.K., Przytulska M., Wierzbicka D.

Biocybernetics and Biomedical Engineering

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1999

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Vol. 19, no. 4

67-78

EN

There is described a class of numerical models of time-varying heart ventricle shapes. It is an extension of the class of models presented in the 1st part of the paper. The below-presented models describe the process of heart ventricle motion within a limited number of heart evolution cycles. The models are based on trigonometric series describing periodic time-variations of heart ventricle shape coefficients. A method of model parameters evaluation based on computer-aided analysis of series of USG heart ventricle images is described and illustrated by practical examples. There are also given some remarks concerning possible applications of the model in clinical practice.

PL

W artykule przedstawiono klasę modeli numerycznych zmian kształtu jam serca w funkcji czasu. Klasa ta jest uogólnieniem klasy modeli przedstawionych w I części artykułu. Przedstawione modele opisują proces ruchu jam w granicach ograniczonej liczby cykli ewolucji serca. Modele są oparte na szeregach trygonometrycznych opisujących zmienność w czasie współczynników kształtu komory serca. Opisano metodę oceny parametrów modelu opartą na analizie komputerowej serii obrazów ultrasonograficznych serca i zilustrowano ją przykładami wziętymi z praktyki. Przedstawiono sugestie odnośnie możliwości wykorzystania modelu w praktyce klinicznej.