3D Segmentation with an application of level set-method using MRI volumes for image guided surgery.

This paper proposes an innovation in the application for image guided surgery using a comparative study of three different method of segmentation. This segmentation method is faster than the manual segmentation of images, with the advantage that it allows to use the same patient as anatomical reference, which has more precision than a generic atlas. This new methodology for 3D information extraction is based on a processing chain structured of the following modules: 1) 3D Filtering: the purpose is to preserve the contours of the structures and to smooth the homogeneous areas; several filters were tested and finally an anisotropic diffusion filter was used. 2) 3D Segmentation. This module compares three different methods: Region growing Algorithm, Cubic spline hand assisted, and Level Set Method. It then proposes a Level Set-based on the front propagation method that allows the making of the reconstruction of the internal walls of the anatomical structures of the brain. 3) 3D visualization. The new contribution of this work consists on the visualization of the segmented model and its use in the pre-surgery planning.

Design and implementation of an acquisition system for the photo-motor response of the iris.

This paper presents a new development of an automated system for: stimulation, acquisition and the pupilar image processing (it includes segmentation and visualization in real time), issued from the fhoto-motor and consensual response of the iris. The physician can observe in the system interface: a graphic representation of the variation and change of speed of diameter and pupilar area as a function of time, from both pupils. In addition the magnitudes of clinical parameters, such as: the largest and smaller pupilar diameter, the maximum and minimum pupilar area, the eccentricity of each pupil, jointly with the inter pupilar distance. These data have a great interest for diagnosis and evaluation of lesions or illnesses of the central nervous system [1], which constitute the third cause of death in Venezuela during the last five years [2]. However, in Venezuela, specialists do not have a system for quantifying the clinical parameters, neither carry out the graphic representations of these important parameters.

Degree of correlation between two periodontal indices in a rural Croatian population.

AIM: To compare the periodontal status of patients measured by two indices, the Community Periodontal Index (CPI) and the Loss of Attachment Index (LA). METHOD: The CPI and LA index scores were determined for a sample of 367 adult subjects (1,535 dentate sextants) aged 15-65 years from two rural areas in Croatia and analysed according to subject, sextant and jaw. RESULTS: Partial correlation between the CPI and LA indices was found. Cumulative for all age groups, sextants with a CPI code 0, 1 and 2 most often appeared with a LA 0-3mm. Shallow pocket sextants (4-5mm) in 64.04% also correlated with the loss of attachment values 4-5mm. In deep pocket sextants (6-8 mm), a deviation from expectations was found as they appeared more often with a LA 9-11 mm designation (46.24%), rather than with an LA 6-8mm (34.41%) score. Very similar results were found between distribution per sextant, person and jaw in CPI codes 2, 3, 4 and cumulatively. CONCLUSION: CPI itself is not sufficient for periodontal status assessment, especially for the 35-44 years of age, and even more so for the 65+ group, also for the CPI code 4 in all ages.

Dental health of elderly in retirement homes of two cities in south Croatia--a cross-sectional study.

OBJECTIVE: A survey of dental health status was conducted in institutionalized elderly in South Croatia in order to assess the oral health of the elderly population. PARTICIPANTS: In 274 institutionalised elderly from five retirement homes in Split and Korcula we registered dental status according to World Health Organization criteria. The mean age of the patients was 81 +/- 8; there were 220 female and 54 male subjects. RESULTS: A total of 192 (70.0%) were totally edentulous, and additional 39 (14.2%) were edentulous in one jaw. A significantly higher prevalence of edentulousness with the increasing age was recorded. The mean number of remaining sound teeth, decayed teeth and radices relictae in the elderly decreased with increasing age. CONCLUSIONS: The elderly population in retirement homes in South Croatia has poor dental health. This calls for action to improve dental health and implement some special features in the dental health service programs for the institutionalised elderly.

Ten-year evaluation of conservative and surgical treatment of gingival recession. A case series study.

In the last years the treatment of non-inflammatory periodontal diseases has greatly changed. Apico-coronal dimension of gingival tissue is not considered to be of utmost importance, but significance of tissue thickness over each tooth is stressed. Purpose of this study was to show results of conservative and surgical treatment of gingival recession. Sample consisted of two groups of subjects, which have been treated in one of stated ways during ten years. The data was obtained on the beginning and after ten years of recall. Both groups showed increased dimension of keratinized gingiva during observed time with decrease of gingival recession, plaque- and gingival index. It is considered that treatment should start with conservative measures with necessary motivation of the patients. If it does not show improvement, one should consider best surgical method available for each patient. Clinical results show success in both groups, meaning that treatment was properly decided on.

Incidence and distribution of dehiscences and fenestrations on human skulls.

The aim of this study was to determine the incidence and distribution of dehiscences and fenestrations of the alveolar plate. The sample used in the study consisted of 163 adult jaw bones (78 maxillae and 85 mandibles) of a recent population from the north-western Croatia. The skulls are part of the skull collection of The Anatomy Institute, Zagreb, Croatia. The number and location of dehiscences and fenestrations for each tooth area above the total number of 2038 teeth were registrated. The total number of 696 (26.67%) dehiscences and 190 (9.32%) fenestrations was measured. Among the maxillary teeth, canines exhibited greatest and most frequent dehiscences and fenestrations. In the mandible, canines were most commonly associated with both defects, too. It was concluded that the canines were most frequently associated with either of the osseous defects.

Bruxism and psychobiological model of personality.

Bruxism is an abnormal activity of the masticatory system, caused by both psychological and occlusal factors. The aim of the study was to determine the possible correlation between the temperament and character of patients and bruxism. Personality profile of 35 bruxism patients, with no history of psychiatric disorder, was studied by means of Cloninger's seven factor model of temperament and character. For diagnosis of bruxism, muscle activity was analysed and occlusal interferences and facets were registered by clinical functional analysis. Temperament and Character Inventory assesses four dimensions of temperament and three dimensions of character. Results suggest that bruxism patients can have following personality traits: exploratory, impulsive, extravagant and irritable, pessimistic, fearful, shy and fatigable, critical, aloof, detached and independent, lazy, spoiled, underachiever and pragmatist. Combined scores of character dimension indicate immature dimensions of character. Inventory is not standardized for the Croatian population, therefore the result should be taken with caution.

Automatic intraductal breast carcinoma classification using a neural network-based recognition system.

A contour-based automatic recognition system was applied to classify intraductal breast carcinoma into high nuclear grade and low nuclear grade in a digitized histologic image. The image discriminating characteristics were selected by their invariability condition to rotation and translation. They were acquired from cellular contours information. The totally interconnected multilayer perceptron network architecture was selected, and it was trained with the error back propagation algorithm. Forty cases were analyzed by the system and the diagnoses were compared with that of pathologist consensus, obtaining agreement in 97.5% (p < .00001 of cases). The system may become a very useful tool for the pathologist in the definitive classification of intraductal carcinoma.

An approach to intelligent ischaemia monitoring.

The paper describes an approach to intelligent ischaemia event detection based on ECG ST-T segment analysis. ST-T trends are processed by means of a Bayesian forecasting approach using the multistate Kalman filter. A complete procedure, intended for use in CCU/ICU monitoring areas, is proposed, in order to give the clinician an intelligent monitoring tool. The approach serves to describe trends and their changes in a symbolic way. A novel aspect is its ability to observe certain features of ST-T elevation/depression not detected by other means, and to reject artefacts and erroneous events. A sensitivity of 89.58% and a predictivity of 84.31% are obtained on selected records of the European ST-T database. Using a restriction on event amplitude, the predictivity is raised to 95.55%. An ischaemia sensitivity index of 1.2 was determined. The method has been shown to be a robust and practical trend analysis tool, and seems to be appropriate for numeric/symbolic transformations in next-generation intelligent monitoring systems.