Gerson Linck Bichinho

A computer tool for the fusion and visualization of thermal and magnetic resonance images.

The measurement of temperature variation along the surface of the body, provided by digital infrared thermal imaging (DITI), is becoming a valuable auxiliary tool for the early detection of many diseases in medicine. However, DITI is essentially a 2-D technique and its image does not provide useful anatomical information associated with it. However, multimodal image registration and fusion may overcome this difficulty and provide additional information for diagnosis purposes. In this paper, a new method of registering and merging 2-D DITI and 3-D MRI is presented. Registration of the images acquired from the two modalities is necessary as they are acquired with different image systems. Firstly, the body volume of interest is scanned by a MRI system and a set of 2-D DITI of it, at orthogonal angles, is acquired. Next, it is necessary to register these two different sets of images. This is done by creating 2-D MRI projections from the reconstructed 3-D MRI volume and registering it with the DITI. Once registered, the DITI is then projected over the 3-D MRI. The program developed to assess the proposed method to combine MRI and DITI resulted in a new tool for fusing two different image modalities, and it can help medical doctors.

Hematoma volumes of spontaneous intracerebral hemorrhage: the ellipse (ABC/2) method yielded volumes smaller than those measured using the planimetric method

OBJECTIVE To compare two different methods for measuring intracerebral hemorrhage (ICH) volume: the ellipse volume (called ABC/2), and the software-aided planimetric. METHODS Four observers evaluated 20 brain computed tomography (CT) scans with spontaneous ICH. Each professional measured the volume using the ABC/2 and the planimetric methods. The average volumes were obtained, and the intra- and inter-rater variability was determined. RESULTS There is an absolute 2.24 cm3 average difference between both methodologies. Volumes yielded by the ABC/2 method were as much as 14.9% smaller than by the planimetric one. An intra-observer variability rate of 0.46% was found for the planimetric method and 0.18% for the ABC/2. The inter-observer rates were 1.69 and 1.11% respectively. CONCLUSIONS Both methods are reproducible. The ABC/2 yielded hemorrhage volumes as much as 14.9% smaller than those measured using the planimetric methodology.

CT slice retrieval by shape ellipses descriptors for skull repairing

This paper addresses the problem of automated prosthesis modelling and manufacturing, whose machining parameters are based on images extracted from different medical databases. The specific case of 3D surface restoration of a defective skull was used as study case. A method based on adjusted ellipses on skull bone curvature performs the symbolic representation of searching parameters. The superellipse concept permits to define geometric parameters to fit an ellipse on each Computed Tomography slice. Those ellipse descriptors can be used as a template for the retrieval of similar images from databases whose parameters match the sampled image. The similarity is measured according to the best fitness values through an optimization algorithm. The slices found by similarity are retrieved from all databases in order to build the 3D model. Experiments show that the proposed method is a promising technique for content based image retrieval.

Classification of chronic obstructive pulmonary disease based on chest radiography

Objective Quantitative analysis of chest radiographs of patients with and without chronic obstructive pulmonary disease (COPD) determining if the data obtained from such radiographic images could classify such individuals according to the presence or absence of disease. Materials and Methods For such a purpose, three groups of chest radiographic images were utilized, namely: group 1, including 25 individuals with COPD; group 2, including 27 individuals without COPD; and group 3 (utilized for the reclassification /validation of the analysis), including 15 individuals with COPD. The COPD classification was based on spirometry. The variables normalized by retrosternal height were the following: pulmonary width (LARGP); levels of right (ALBDIR) and left (ALBESQ) diaphragmatic eventration; costophrenic angle (ANGCF); and right (DISDIR) and left (DISESQ) intercostal distances. Results As the radiographic images of patients with and without COPD were compared, statistically significant differences were observed between the two groups on the variables related to the diaphragm. In the COPD reclassification the following variables presented the highest indices of correct classification: ANGCF (80%), ALBDIR (73.3%), ALBESQ (86.7%). Conclusion The radiographic assessment of the chest demonstrated that the variables related to the diaphragm allow a better differentiation between individuals with and without COPD.

Audiometric evaluation after stapedotomy with Fisch titanium prosthesis

UNLABELLED Otosclerosis causes the fixation of the stapes and conductive hearing loss, usually corrected with the use of hearing aids or through stapedotomy and the replacement of the involved stapes with a prosthesis. Titanium has been the most recently used material of choice in stapedotomy prostheses. Only two prostheses are commercially available in Brazil. There are no reports in the literature on the Fisch-type Storz titanium stapes piston prosthesis. OBJECTIVE This retrospective study aims to look into the auditory outcomes of patients submitted to stapedotomy and titanium stapes piston prosthesis implantation. METHOD The criteria described by the American Academy of Otolaryngology were used to compare pre and postoperative air-bone gaps seen in audiometry tests. RESULTS The mean low-frequency postoperative air-bone gap was 12.9 dB; the mean high-frequency air-bone gap was 5.2 dB (mean 9.1 dB); median gap was 8.8 dB, with a minimum of 1.3 dB and a maximum of 21.6 dB; standard deviation was 5.7 dB, and p < 0.001. Twenty-five (75.8%) patients had air-bone gaps of 10 dB and under; 32 (96.9%) patients had gaps of 20 dB and under; and all patients had gaps of 30 dB and under. CONCLUSION The Fisch-type titanium stapes piston prosthesis presented outcomes consistent with the literature and can be used safely in stapedotomy procedures.

Análise da radiografia de tórax de indivíduos com DPOC e sua correlação com os testes funcionais

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) causes changes in respiratory function and alters the musculoskeletal structures of the chest, increasingly limiting an individuals ability to breathe. OBJECTIVES: To quantitatively analyze chest radiographs of patients with COPD and establish a comparison among the pulmonary function, respiratory muscle strength, thoracic mobility, functional capacity and findings of radiographic exams. METHOD: We studied 15 subjects with COPD who performed the spirometry test, the six-minute walk, manovacuometry and micrometry. The values obtained from these tests were compared with measurements made on chest radiographs of these patients. The values obtained for each variable were normalized by dividing them by retrosternal height. RESULTS: The variable that correlated most significantly with the variables of spirometry (FVC and PEF) and cirtometry (Xiphoid CR and Axillary CR) was the costo-phrenic angle. The image variable ALB DIR positively correlated with the variable PI max. The level of left diaphragmatic drawdown, intercostals right and left distances were not correlated with the variables of physiotherapy exams. CONCLUSION: The variable that correlated most significantly with the tests was the costo-phrenic angle, which indicates that the involvement of the diaphragm has impact on the general conditions of COPD. Thus, the study showed that impairment of the diaphragm in patients with COPD observed in tests of physiotherapy correlate with image variables that assess the diaphragm in radiography.

Morphometric effects of different energy densities of diode laser on adipose tissue in rats

The aim of this study consisted in evaluating the influence of low power laser on the morfometry of white adipose cells in rats. The sample consisted of 20 adult female rats, from Wistar strain, randomized in four groups. All groups were submitted to tricotomy of the dorsal thoracic area and the first three groups were exposed to a InGaAlP laser (660 nm wavelength) with fluencies of 2, 8 and 16 J/cm2 for groups L1, L2 and L3, respectively. L4 was the control. The groups were submitted to the protocols three times a week, for three weeks. The irradiated tissue was excised and submitted to histological treatment by HE for optical microscopy and the Kruskal-Wallis test was used for the statistical analysis. The average morphometry, in number of pixels, was: 3741 ± 704, 3762 ±947, 3737 ±1076 and 4619 ±781 for L1, L2, L3 and L4, respectively. There was no significant difference among groups L1 to L3 for the variable tested. From these results, it can be concluded that the application of low power laser - under the conditions proposed and for the fluency values chosen - influence the morphometry of white adipose cells in rats in the same manner, producing similar results.