Biomedical subjects

Daniel Smutek

Publications and source records attributed to Daniel Smutek.

4 recordsLinked to original sources

PubMed2003

Image texture analysis of sonograms in chronic inflammations of thyroid gland.

The current practice in assessing sonographic findings of chronic inflamed thyroid tissue is mainly qualitative, based just on a physician's experience. This study shows that inflamed and healthy tissues can be differentiated by automatic texture analysis of B-mode sonographic images. Feature selection is the most important part of this procedure. We employed two selection schemes for finding recognition-optimal features: one based on compactness and separability and the other based on classification error. The full feature set included Muzzolini's spatial features and Haralick's co-occurrence features. These features were selected on a set of 2430 sonograms of 81 subjects, and the classifier performance was evaluated on a test set of 540 sonograms of 18 independent subjects. A classification success rate of 100% was achieved with as few as one optimal feature among the 129 texture characteristics tested. Both selection schemes agreed on the best features. The results were confirmed on the independent test set. The stability of the results with respect to sonograph setting, thyroid gland segmentation and scanning direction was tested.

Algorithms↗

PubMed2003

Relation between quantitative description of ultrasonographic image and clinical and laboratory findings in lymphocytic thyroiditis.

OBJECTIVE: Relations between measurable properties of B-mode ultrasound images of thyroid gland and clinical and laboratory findings in patients with chronic inflammation of thyroid gland were studied. METHODS: Data from 65 patients with lymphocytic thyroiditis (LT) and 38 control subjects were analysed. Raw values of individual B-mode image pixels and standard co-occurrence second-order texture features were selected as quantitative image features. Thyroid antibodies, thyrotropin level, thyroxine replacement therapy, and body mass index were used as clinical variables. RESULTS: In the LT group, significant differences (t-tests, p<0.05) in image features were found for body mass indices (BMI) under and over 25 kg.m(-2), for thyroxine replacement therapy, and for the presence and absence of thyroid antibodies. Forward stepwise multiple regression was performed for the clinical or laboratory values as dependent variables and image features as independent variables. The following correlations were found: 1. between BMI and four image features in the normal group; 2. between the dose of thyroxine replacement therapy and two of image features in the LT group; and 3. for the level of thyroid antibodies in the LT group: five image features have correlated with the level of anti-thyroglobulin and three image features with level of anti-thyroperoxidase. CONCLUSION: These findings suggest the possibility of using quantitative indicators of ultrasound image of thyroid gland as predictors of the presence or absence of thyroid antibodies in patient's blood or as an auxiliary tool for dose recommendation of thyroxine replacement therapy.

Adolescent↗

PubMed2002

Quantitative indicators of sonographic image of thyroid gland and their relation to antithyroid antibodies in Hashimoto's lymphocytic thyroiditis.

Sonography is a widely used non-invasive diagnostic tool and its main advantage is low cost in comparison with other diagnostic methods such as immunological analyses. In this work it is presented the relation between a sonographic image of thyroid gland and an immunological status of the patients with Hashimoto's lymphocytic thyroiditis (chronic inflammation of the thyroid gland). The results, evaluated on a set of 740 B-mode sonographic images from 37 subjects, show that raw values of individual image pixels in sonogram of thyroid gland with presence and without presence of anti-thyroid antibodies are significantly different (means 31.87 and 44.56; standard deviations 8.6 and 11.82; t = 3.4; p = 0.0017) and that they can be used for the prediction of presence of anti-thyreoglobulin and anti-thyreoperoxidasis antibodies. This result suggests the possibility to use this method in clinical diagnostic process for reducing the costs. Also the correlation between the image features and the level of antibodies was examined. The highest correlation was found for inverse difference moment and the level of anti-thyreoperoxidasis (coefficient of determination 0.43).

Autoantibodies↗

PubMed2002

Representing clinical guidelines in UMl: a comparative study.

Clinical guidelines can be represented using models, such as GLIF, specifically designed for healthcare guidelines. This paper demonstrates that they can also be modelled using a mainstream business modelling language such as UML. The paper presents a guideline in GLIF and as UML activity diagrams, and then presents a mapping of GLIF primitives to UML. The potential benefits of using a mainstream modelling language are outlined. These include availability of advanced modelling tools, transfer between modelling tools, and automation via business workflow technology.

Diabetes Mellitus↗