Vol. 3, No 4, 1999 < Volumes
(ISSN 1428-6394)

Guest editor: prof. A. Nowakowski, antowak@sunrise.pg.gda.pl
Technical University of Gdansk, Poland

Contents:

  • A.Bruckmann, H.Flatscher, Th.Schell and A.Uhl, Adaptive Wavelet Techniques for Compressing Digital Mammograms | abstract
  • K.Palagyi, E.Sorantin, C.Halmai and A.Kuba, 3D Thinning and its Applications to Medical Image Processing | abstract
  • C.A.Glasbey and C.D.Robinson, Estimation of Tissue Proportions in X-ray CT Images Using a New Mixed Pixel Distribution | abstract
  • J.Ruminski, Similarity Analysis in Medical Image Databases | abstract
  • T.Gorajek and A.Nowakowski, Electroimpedance Tomography as a Tool for Brain Examination | abstract
  • R.Kalicka and D.Bochen, Reliability and Efficiency of the D, E, S, A-Optimal Sampling Schedule Design | abstract
  • E.Pietka, Database of Diagnostic Images in Hospital Integrated Picture Archiving and Communication Systems | abstract
  • J.Ruminski and A.Nowakowski, Integrated, Radiological Database Structure | abstract
  • Z.S.Hippe, Computer Database 'Nevi' on Endangerment by Melanoma | abstract

From the History of Science and Technology in Ancient Gdansk:

  • A.Januszajtis, The Bells of Gdansk and Their Musics

Abstracts:

h A.Bruckmann, H.Flatscher, Th.Schell and A.Uhl, Adaptive Wavelet Techniques for Compressing Digital Mammograms

In this work we investigate the possible benefit of employing adaptive wavelet algorithms instead of the classical fixed pyramidal wavelet decomposition for the compression of digital mammograms. In particular, we target on adaptive wavelet packet and NSMRA decompositions. We observe that information cost function optimized wavelet packet subband structures do not offer compression performance gain in this case whereas NSMRA decompositions moderately improve the results of classical wavelet decompositions. Due to the lack of fast and reliable search algorithms fixed NSMRA decompositions need to be generated and employed for classes of similar images.

 

h K.Palagyi, E.Sorantin, C.Halmai and A.Kuba, 3D Thinning and its Applications to Medical Image Processing

Skeleton is a frequently used feature to represent general form of an object. The importance of that region-based shape feature shows an upward tendency in medical image processing, too. This paper summarizes the major skeletonization approaches, the parallel thinning methodologies in 3D, and some emerged medical applications. An application to calculate the cross-sectional profiles of blood vessels is also presented.

 

h C.A.Glasbey and C.D.Robinson, Estimation of Tissue Proportions in X-ray CT Images Using a New Mixed Pixel Distribution

A new probability distribution is obtained, termed the mixed pixel distribution, appropriate for the mixing proportion in digital images when the point s pread function has a bivariate normal density. It is used to derive the distribution of pixel values in X-ray CT images where pixels may be a mixture of two tissue types. In a simulation study it is shown that, by fitting this distribution to histograms of pixel values, tissue proportions are estimated more accurately than using threshold-based methods.

 

h J.Ruminski, Similarity Analysis in Medical Image Databases

The review of methods of similarity analysis of medical images is presented. Feature extraction, feature representation and different concepts of image query algebra problems are described and discussed from the medical application point of view. New algorithms based on medical image regularity description and intensity description are proposed. As a conclusion a Java application "ObrazMed" for content based medical image analysis is presented.

 

h T.Gorajek and A.Nowakowski, Electroimpedance Tomography as a Tool for Brain Examination

The aim of this paper is to discuss the possibility of a successful Electroimpedance Tomography (EIT) reconstruction of an impedance distribution within a human head taking into consideration the presence of a skull and its screening effect for electrical signals. The results of numerous computer simulations of the processes of impedance measurements and 3D EIT reconstruction are presented. The volume of the smallest recognisable perturbation within both brain and skull areas are determined as well as their relationships with the required contrast. The unquestionable usefulness of EIT approach for the purposes of impedance modelling is proven.

 

h R.Kalicka and D.Bochen, Reliability and Efficiency of the D, E, S, A-Optimal Sampling Schedule Design

Due to sharp practical and ethical constraints imposed on medical measurements, the parameter estimation procedure designed for diagnosis and therapy, is often a difficult problem. When blood sampling provides the data, the number of samples and the measurement interval should be minimised. We have implemented D, E, S, A-optimal sampling schedule (OSS). These OSS have minimal size, which means that number of samples is equal to the number of model parameters that are being estimating. Setting-up the results of D, E, S and A approaches allows to compare their efficiency and usefulness. Illustrative examples are presented.

 

h E.Pietka, Database of Diagnostic Images in Hospital Integrated Picture Archiving and Communication Systems

Implementation of database management system in clinical open-architecture Picture Archiving and Communication System (PACS) has been discussed. Standardization of communication protocols and file formats permit the equipment of various vendors to be linked. Main functions of the database management system at two levels of the system are introduced. Clinical experiences show three main advantages which cause an increasing interest in this concept. Access time, computer-assisted diagnosis, and cost-effectiveness are parameters describing the system efficiency.

 

h J.Ruminski and A.Nowakowski, Integrated, Radiological Database Structure

The rapid development of medical imaging requires proper preparation of medical database structure for multimedia information acquired during patient visit. This paper presents a study on integrated structure of a radiological database based on DICOM, HL7 standards and on medical coding systems. Conclusions are based on the Radiological Information System project prepared for the Institute of Radiology, Medical University of Gdansk.

 

h Z.S.Hippe, Computer Database 'Nevi' on Endangerment by Melanoma

The database containing statistically meaningful number of carefully veri-fied cases of nevi pigmentosi (in four categories: benign nevus, blue nevus, suspi-cious nevus, and melanoma malignant) has been described. Then, various experiments of controlled data mining were performed to get an insight for the new interpretation of the TDS coefficient, broadly used in the initial classification of endangerment by me-la-noma tumor

 

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