A new clinical sign probably associated to left hemiplegia with left hemineglect syndrome: the crossed legs

Objetivo : Descrever um novo sinal clínico associado à síndrome de negligência unilateral (SNU) em pacientes com acidente vascular cerebral isquêmico (AVCi). Método : Em 150 pacientes com acidente vascular cerebral isquêmico, foram realizadas tomografias de crânio e aplicada a National Institute of Health Stroke Scale. Aqueles pacientes com lesões vasculares à direita, hemiplegia esquerda e perna direita persistentemente cruzada sobre a esquerda, foram submetidos a testes específicos para SNU. Trinta pacientes também com lesões vasculares à direita, hemiplegia esquerda, porém sem evidências de permanecerem com as pernas cruzadas, foram submetidos aos mesmos testes clínicos. Resultados : Entre 150 pacientes com AVCi, 9 apresentaram lesão vascular cerebral à direita, hemiplegia esquerda e tendência em permanecer com a perna direita cruzada sobre a esquerda. Em 8 deles, testes específicos realizados nos primeiros dias de internação, confirmaram SNU à esquerda. Um paciente morreu antes que os testes pudessem ser aplicados. Dos 30 pacientes que não cruzaram as pernas, os testes foram normais em 20. Dez pacientes apresentaram alterações mínimas, insuficientes para o diagnóstico de SNU. Conclusão : A perna direita cruzada sobre a esquerda pode representar um novo sinal semiológico associado à hemiplegia esquerda e SNU à esquerda.

Proposal to utilize simplified Swensen protocol in diagnosis of isolated pulmonary nodule

Background: The problem of diagnosing whether a solitary pulmonary nodule is benign or malignant is even greater in developing countries due to a higher prevalence of infectious diseases. These infections generate a large number of patients who are generally asymptomatic and with a pulmonary nodule that cannot be accurately defined as having benign or malignant etiology.Purpose: To verify the percentages of benign versus malignant non-calcified nodules, the length of time after contrast agent injection is spiral computed tomography (CT) most sensitive and specific, and whether three postcontrast phases are necessary.Material and Methods: We studied 23 patients with solitary pulmonary nodules identified on chest radiographs or CT. Spiral scans were obtained with Swensen protocol, but at 3, 4, and 5 min after contrast injection onset. Nodules were classified as benign or malignant by histopathological examination or by an absence or presence of growth after 2 years of follow-up CT.Results: Of the 23 patients studied, 18 (78.2%) showed a final diagnosis of benign and five (21.7%) malignant nodules. Despite the small sample size, we obtained results similar to those of Swensen et al., with 80.0% sensitivity, 55.5% specificity, and 60.8% accuracy. Four minutes gave the greatest mean enhancement in both malignant and benign lesions.Conclusion: Small non-calcified benign nodules were much more frequent than malignant nodules. The best time for dynamic contrast-enhanced CT density analysis was 4 min postcontrast. As well as saving time and money, this simplified Swensen protocol with only precontrast and 4 min postcontrast phases also reduces patient exposure to ionizing radiation.

Wavelets based Algorithm for the Evaluation of Enhanced Liver Areas

Hepatocellular carcinoma (HCC) is a primary tumor of the liver. After local therapies, the tumor evaluation is based on the mRECIST criteria, which involves the measurement of the maximum diameter of the viable lesion. This paper describes a computed methodology to measure through the contrasted area of the lesions the maximum diameter of the tumor by a computational algorithm 63 computed tomography (CT) slices from 23 patients were assessed. Non-contrasted liver and HCC typical nodules were evaluated, and a virtual phantom was developed for this purpose. Optimization of the algorithm detection and quantification was made using the virtual phantom. After that, we compared the algorithm findings of maximum diameter of the target lesions against radiologist measures. Computed results of the maximum diameter are in good agreement with the results obtained by radiologist evaluation, indicating that the algorithm was able to detect properly the tumor limits A comparison of the estimated maximum diameter by radiologist versus the algorithm revealed differences on the order of 0.25 cm for large-sized tumors (diameter > 5 cm), whereas agreement lesser than 1.0cm was found for small-sized tumors. Differences between algorithm and radiologist measures were accurate for small-sized tumors with a trend to a small increase for tumors greater than 5 cm. Therefore, traditional methods for measuring lesion diameter should be complemented with non-subjective measurement methods, which would allow a more correct evaluation of the contrast-enhanced areas of HCC according to the mRECIST criteria.

Quantification of Biological Tissue and Construction of Patient Equivalent Phantom (Skull and Chest) for Infants (1-5 years old)

Our main purpose in this study was to quantify biological tissue in computed tomography (CT) examinations with the aim of developing a skull and a chest patient equivalent phantom (PEP), both specific to infants, aged between 1 and 5 years old. This type of phantom is widely used in the development of optimization procedures for radiographic techniques, especially in computed radiography (CR) systems. In order to classify and quantify the biological tissue, we used a computational algorithm developed in Matlab (R). The algorithm performed a histogram of each CT slice followed by a Gaussian fitting of each tissue type. The algorithm determined the mean thickness for the biological tissues (bone, soft, fat, and lung) and also converted them into the corresponding thicknesses of the simulator material (aluminum, PMMA, and air). We retrospectively analyzed 148 CT examinations of infant patients, 56 for skull exams and 92 were for chest. The results provided sufficient data to construct a phantom to simulate the infant chest and skull in the posterior anterior or anterior posterior (PA/AP) view. Both patient equivalent phantoms developed in this study can be used to assess physical variables such as noise power spectrum (NPS) and signal to noise ratio (SNR) or perform dosimetric control specific to pediatric protocols.

Análise tomográfica, histológica, histométrica e imunoistoquímica do beta tricálcio fosfato com osso autógeno em aumento do soalho de seio maxilar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comparativo do processo de reparo utilizando osso autógeno e beta-tricálcio fosfato em levantamento do assoalho do seio maxilar em humanos: análise tomográfica, histológica, histométrica e imunoistoquímica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Central Giant Cell Granuloma in Pediatric Maxilla: Surgical Management

Central giant cell granuloma (CGCG) is an intraosseous lesion consisting of fibrous cellular tissue that contains multiple foci of hemorrhage, multinucleated giant cells, and occasional trabeculae of woven bone. An 8-year-old boy presented himself complaining of a painless swelling in the left maxilla that had started 1 year. Computed tomography (CT) scan confirmed a poorly defined multilocular radiolucent lesion in the left maxilla crossing the midline. The patient underwent enucleation through an intraoral approach of the lesion. The biopsy revealed multinucleated giant cells in a fibrous stroma. A CT was taken approximately 1 year postoperatively. There was no clinical or radiographic evidence of recurrence. Therefore, surgical treatment of CGCG can be performed, trying to preserve the surrounding anatomic structures, which can be maintained in case the lesion does not show an aggressive clinical behavior, avoiding large surgical defects which are undesirable in children.

Avaliação das condições de uso de um equipamento de tomografia computadorizada e otimização de protocolos de crânio empregados na rotina do HCFMB-UNESP

Almost forty years computed tomography (CT) has been one of the most powerful tools in diagnostic imaging. However, this modality delivers relatively high doses to their patients. It is known that the inappropriate use and unnecessary radiation may be associated with a significant risk of cancer, especially in pediatric patients. Moreover, the quality assurance in CT, provided and required by Portaria 453/98 and the guide of the RE 1016/05, ensures that the images generated by computer tomography provide reliable diagnostic information with doses as low as reasonably achievable. This research aimed to make the quality control (QC) of CT equipment; establish a better relationship between dose and noise on the image to protocols of skull CT according to the study of optimization proposed in 2005 by Daros; and assess the dose distribution in different cranial organs for protocols of adult and pediatric use in the routine of the Department of Diagnostic Imaging of HCFMB-UNESP. The equipment used for testing QC, optimization and dosimetry was a third generation tomograph GE Sytec 3000i

Análise da viabilidade de simulações com feixes de prótons de 100, 150, 200 e 250 MeV em alvos heterogêneos

In the recent years, the use of proton beams in radiotherapy has been an outstanding progress (SMITH, 2006). Up to now, computed tomography (CT) is a prerequisite for treatment planning in this kind of therapy because it provides the electron density distribution required for calculation of dose and the interval of doses. However, the use of CT images for proton treatment planning ignores fundamental differences in physical interaction processes between photons and protons and is, therefore, potentially inaccurate (SADROZINSKI, 2004). Proton CT (pCT) can in principle directly measure the density distribution needed in a patient for the dose distribution (SCHULTE, et al, 2004). One important problem that should be solved is the implementation of image reconstruction algorithms. In this sense, it is necessary to know how the presence of materials with different density and composition interfere in the energy deposition by ionization and coulomb excitation, during its trajectory. The study was conducted in two stages, was used in both the program SRIM (The Stopping and Range of Ions in Matter) to perform simulations of the interaction of proton beams with pencil beam type. In the first step we used the energies in the range of 100-250 MeV (ZIEGLER, 1999). The targets were set to 50 mm in length for the beam of 100 MeV, due to its interaction with the target, and short-range, and 70 mm for 150, 200 and 250 MeV The target was composed of liquid water and a layer of 6 mm cortical bone (ICRP). It were made 9 simulations varying the position of the heterogeneity of 5 mm. In the second step the energy of 250 MeV was taken out from the simulations, due to its greater energy and less interaction. The targets were diminished to 50 mm thick to standardize the simulations. The layer of bone was divided into two equal parts and both were put in the ends of the target... (Complete abstract click electronic access below)

Neuroimagem de encéfalo de gatos domésticos: correlação entre tomografia computadorizada e cortes anatômicos

Pós-graduação em Cirurgia Veterinária - FCAV

Construção de fantomas homogêneos pediátricos de crãnio e tórax para otimização de imagens em radiografia computadorizada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bacterial cellulose-hydroxyapatite composites with osteogenic growth peptide (OGP) or pentapeptide OGP on bone regeneration in critical-size calvarial defect model

This study aimed to evaluate the potential of bacterial cellulose-hydroxyapatite (BC-HA) composites associated with osteogenic growth peptide (OGP) or pentapeptide OGP(10–14) in bone regeneration in critical-size calvarial defects in mice. In this study, the BC-HA, BC-HA-OGP, and BC-HA-OGP(10–14) membranes were analyzed at 3, 7, 15, 30, 60, and 90 days. In each period, the specimens were evaluated by micro-computed tomography (µCT), descriptive histology, gene expression of bone biomarkers by qPCR and VEGFR-2 (vascular endothelial growth factor) quantification by ELISA. Three days post-operative, Runx2, Tnfrsf11b and Bglap bone biomarkers were upregulated mainly by BC-HA OGP and BC-HA OGP(10–14) membranes, suggesting an acceleration of the osteoblast differentiation/activity with the use of these biomaterials. At 60 and 90 days, a high percentage of bone formation was observed by µCT for BC-HA and BC-HA OGP(10–14) membranes. High expression of some bone biomarkers, such as Alpl, Spp1, and Tnfrsf11b, was also observed for the same membranes on days 60 and 90. In conclusion, the BC-HA membrane promoted a better bone formation in critical-size mice calvarial defects. Nevertheless, incorporation of the peptides at the concentration of 10−9 mol L−1 did not improve bone regeneration potential in the long-term.

The H2S-releasing naproxen derivative, ATB-346, inhibits alveolar bone loss and inflammation in rats with ligature-induced periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diagnóstico e planejamento em cirurgia parendodôntica: utilização da tomografia cone beam

The ability to tridimensionally evaluate pathological and anatomical areas, in apical surgery planning, presents a number of advantages. Cone beam computed tomography (CBCT) was developed for dental applications. This paper aims to present a literature review on CBCT, highlighting its advantages over both conventional computed tomography (CT) and radiography. Moreover, its clinical applications in apical surgery are discussed. LITERATURE REVIEW AND CONCLUSION: Unlikely CT, CBCT captures a volume of data in a single 360º rotation, providing benefits such as higher accuracy, better resolution, reduced scanning time and reduced radiation dose. In the maxillofacial region, CBCT has been mainly used in the assessment of dento-alveolar pathology and oral traumatology. CBCT provides a better diagnosis and quantitative information on periodontal bone levels than conventional radiography. It has also been used for patients requiring surgical facial reconstruction, orthognathic surgery, dental implants, and more complex tooth extractions. Besides that, it seems to be a significant tool in modern endodontic practice, presenting useful applications in apical surgery.

Behaviour of the buccal crestal bone levels after immediate placement of implants subjected to immediate loading

The aim of this study was to measure changes in buccal alveolar crestal bone levels after immediate placement and loading of dental implants with Morse taper prosthetic abutments after tooth extraction. This study followed the STROBE guidelines regarding prospective cohort studies. The sample comprised 12 patients with a mean age of 45 years, in whom a central or upper lateral incisor was indicated for extraction. Prior to extraction, computed tomography (CT) analysis was carried out to assess the presence of the buccal bone crest. CT scans were performed at 24 h and at 6 months after immediate implant placement and immediate loading. The distance from the most apical point of the implant platform to the buccal bone crest was assessed at the two time points. The buccal bone crest height was evaluated at three points in the mesio-distal direction: (1) the centre point of the alveolus, (2) 1 mm mesial to the centre point, and (3) 1 mm distal to the centre point. The values obtained were subjected to statistical analysis, comparing the distances from the bone crest to the implant platform for the two time points. After 6 months there was a statistically significant, non-uniform reduction in height at the level of the crest of the buccal bone in the cervical direction. It is concluded that the buccal bone crest of the immediate implants that replaced the maxillary incisors underwent apical resorption when subjected to immediate loading.