189 resultados para computed tomography images
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This paper reports one case, of an ameloblastic fibro-odontosarcoma (AFOS) affecting the mandible, in a 12-year-old girl. This neoplasm is a rare odontogenic neoplasm. To the authors' knowledge this is the fifteenth case of AFOS reported in English. The patient's chief complaint was a swelling in the face For 6 months. An incisional biopsy was performed diagnosing the case as all ameloblastic fibroma. After radiography ameloblastic fibro-odontoma was diagnosed. Computed tomography was performed and a stereolithography model made to plan the surgical procedures. A hemimandibulectomy followed by a vascularized fibular flap was then proposed. The surgery was uneventful. Microscopic features diagnosed an AFOS. After 23 months of close follow-up there is no sign of recurrence or metastasis. Dental implants were recently placed in the fibular flap.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The purpose of this case report was to describe the successful long-term conservative management of a root-fractured permanent maxillary right central incisor in an 8-year-old patient. After the initial approach of splinting the traumatized tooth, the patient was followed on a regular basis for 15 years. Clinically, the crown of the root-fractured incisor showed no displacement or discoloration, and thermal tests suggested pulp vitality over the follow-up period. Radiographically, an increase in the diastasis was observed between the apical and coronal fragments due to both the growth of the alveolar process and the healing with interposition of hard and soft tissue between the fragments and confirmed with computed tomography scan in the 15-year follow-up appointment. (Pediatr Dent 2012;34:156-8) Received June 21, 2010 vertical bar Lost Revision August 18, 2010 vertical bar Accepted August 27, 2010
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BACKGROUND: Ultrasonography (US), Computed Tomography (CT), and Magnetic Resonance imaging (MR) were compared for the staging of renal tumors. The differences between these imaging techniques were also studied for their ability to detect adenopathies, vascular invasion, distant intra-abdominal metastases, and particularly adjacent organ invasion. METHODS: Thirty-one patients with solid or complex renal masses were prospectively studied using US, CT, and MR. Differences between the results obtained were studied using the COCHRAN G test and the McNEMAR test. The sensitivity and specificity of each diagnostic technique were compared against a gold standard of the surgical and histopathological findings. RESULTS: The following sensitivities were obtained: For the detection of adenopathy, US 63.6%, CT and MR 90.9%. For vascular invasion, US 42.8%, CT and MR 85.7%. For the adjacent organ invasion, US 28.5%, CT 85.7%, and MR 71.4%. Some of the criteria that suggest invasion of adjacent structures include: the envelopment of the adjacent structures by the tumor, tumor extension into the adjacent structures with an irregular appearance, and alterations in shape, size, and density of adjacent structures. Loss of fat planes between the tumor and adjacent structures is not a sign of tumor invasion. CONCLUSIONS: Significant differences were found in the detection capacity of US in relation to CT and MR, which were similar. All three techniques were highly sensitive and specific only in the detection of distant abdominal metastases. In addition to the accuracy of these diagnostic modalities for the detection and staging of tumors, invasiveness, risks and cost should be considered in relation to relative costs and benefits.
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Deep venous thrombosis is a relatively common disease, which can present pulmonary embolism as a complication in its acute phase, and later the post-thrombotic syndrome. Thus, diagnosis should be made as soon as possible, in order to prevent or minimize such complications. Several studies have shown that the symptoms and the clinical signs are inaccurate for the deep venous thrombosis diagnosis and that complementary exams are necessary. As an attempt to simplify the patients' assessment, Well et al., in 1997, developed a clinical prediction index that combines symptoms, signs and risk factors for deep venous thrombosis and managed to make a simpler approach through an association of this index with the complementary exams. Phlebography has been considered the gold standard of complementary exams. However, since it is an invasive exam and thus subject to complications, other diagnostic methods were introduced aiming at making the diagnostic approach simpler and less invasive. Doppler ultrasound, duplex scan, impedance plethysmography, computed tomography, and blood tests such as the D-dimer are some of the available methods for assessing the patient with suspicion of deep venous thrombosis. Among them, duplex scan has shown excellent accuracy and it is currently widely accepted as the first choice test for approaching the patient with deep venous thrombosis. Several authors have suggested an association of diagnostic methods to simplify and make the assessment of such patients more cost-effective, leading to the introduction of a wide range of diagnostic strategies. The different diagnostic methods used for assessing deep venous thrombosis are discussed, as well as a review of the literature on the accuracy, advantages and disadvantages of these methods. Copyright © 2005 by Sociedade Brasileira de Angiologia e Cirurgia Vascular.
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OBJECTIVE: To evaluate the persistency of foramen of Huschke by means of computed tomography study of the ear region and approaching important clinical aspects related to the presence of this anatomical anomaly. MATERIALS AND METHODS: Two examiners have analyzed the whole tympanic portion of temporal bone in 150 bilateral computed tomography studies of the ear region, searching for foramen of Huschke presence or absence. RESULTS: The mentioned anatomical anomaly was found in 17 cases (11.3%), 13 patients (76.5%) being female and four (23.5%) male. This higher female incidence is statistically confirmed. CONCLUSION: Ear and/or temporomandibular joint specialists should turn their attention to the persistency of foramen of Huschke.
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Masseter muscle hypertrophy is characterized by unilateral or bilateral enlargement of the masseter muscles affecting both males and females after puberty. Its etiology remains unknown. Limitations on mouth opening and also tension in the region of the hypertrophied muscle are symptoms reported. This paper reports a case of masseter muscle hypertrophy diagnosed using imaging modalities such as conventional radiography, computed tomography and magnetic resonance imaging scans. The familiarity with this condition is important to settle the differential diagnosis with other pathologies such as parotid gland tumors and dental infection.
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The information concerning the molecular events taking place in onlay bone grafts are still incipient. The objective of the present study is to correlate the effects of perforation of resident bone bed on (1) the timing of onlay autogenous graft revascularization; (2) the maintenance of volume/density of the graft (assessed through tomography); and (3) the occurrence of bone remodeling proteins (using immunohistochemistry technique) delivered in the graft. Thirty-six New Zealand White rabbits were subjected to iliac crest onlay bone grafting on both sides of the mandible. The bone bed was drill-perforated on one side aiming at accelerating revascularization, whereas on the other side it was kept intact. After grafts fixation and flaps suture all animals were submitted to tomography on both mandible sites. Six animals were sacrificed, respectively, at 3, 5, 7, 10, 20 and 60 days after surgery. A second tomography was taken just before sacrifice. Histological slides were prepared from each grafted site for both immunohistochemistry analysis [osteopontin, osteocalcin, type I collagen and vascular endothelial growth factor (VEGF) anti-bodies] and histometric analysis. The values on bone volume measured on tomography showed no statistic significance (P≥0.05) between perforated and intact sites. Grafts placed on perforated beds showed higher bone density values compared with non-perforated ones at 3 days (P≤0.05). This correlation was inverted at 60 days postoperatively. The findings from VEGF labeling revealed a tendency for earlier revascularization in the perforated group. The early revascularization of bone grafts accelerated the bone remodeling process (osteocalcin, type I collagen and osteopontin) that led to an increased bone deposition at 10 days. The extended osteoblast differentiation process at intermediate stages in the perforated group cooperated for a denser bone at 60 days. © 2008 Blackwell Munksgaard.
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OBJECTIVE: To obtain mean angulation values for renal hila in relation to the horizontal plane traced over the right and left spinal erector muscles, considering the center of the lumbar vertebral spine as a parameter for measuring the renal hila angles. MATERIALS AND METHODS: The authors have analyzed 250 abdominal computed tomography studies of both male and female healthy individuals (128 men with mean age 52.45 ± 17.42 years, and 122 women with mean age 54.39 ± 18.27 years), corresponding to 500 renal hila evaluated. The mean angulation of each hilum in relation to the horizontal plane was obtained taking acute angles into consideration. RESULTS: The comparative study have not found any statistically significant difference in acute angles of renal hila between male and female individuals. The statistical analysis demonstrated limits of 40.40° and 44.54° for mean right hilum angulation and 39.91° and 43.23° for mean left hilum angulation, with a confidence interval of 95% CONCLUSION: Renal hila present similar angulation independently of sex. Higher angulation values correspond to hyper-rotation or excessive rotation, and lower angulation values, to incomplete or reverse rotation. © Colégio Brasileiro de Radiologia e Diagnóstico por Imagem.
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Proton radiation therapy is a precise form of radiation therapy, but the avoidance of damage to critical normal tissues and the prevention of geographical tumor misses require accurate knowledge of the dose delivered to the patient and the verification of his position demand a precise imaging technique. In proton therapy facilities, the X-ray Computed Tomography (xCT) is the preferred technique for the planning treatment of patients. This situation has been changing nowadays with the development of proton accelerators for health care and the increase in the number of treated patients. In fact, protons could be more efficient than xCT for this task. One essential difficulty in pCT image reconstruction systems came from the scattering of the protons inside the target due to the numerous small-angle deflections by nuclear Coulomb fields. The purpose of this study is the comparison of an analytical formulation for the determination of beam lateral deflection, based on Molière's theory and Rutherford scattering with Monte Carlo calculations by SRIM 2008 and MCNPX codes. © 2010 American Institute of Physics.
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In this report, we present a case of myositis ossificans traumatica (MOT) of the medial pterygoid muscle that had developed after mandibular block anesthesia administered for endodontic treatment of the lower right second molar, demonstrating typical features of this condition. MOT should be considered as a differential diagnosis when there is severe limitation of jaw opening and an associated trauma. Panoramic radiographs and axial and coronal computed tomography (CT) scans can effectively delineate the calcified mass. Other imaging studies that may be helpful include magnetic resonance imaging (MRI), bone scans, and ultrasound. As shown in our case, calcified masses were found in the right mandibular angle, which severely limited jaw opening. Some earlier reported cases of MOT were treated by extraoral surgical approaches with complete removal of the evolving muscle. The aim of this case report is to present only the diagnostic imaging aspects of myositis ossificans traumatica.
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Background: This article describes a clinical report with a new system for guided surgical treatment and immediate load prosthesis in the flapless surgical technique. Case report: Based on a computed tomography (CT) of a 64 - year-old edentulous patient, the cross sections were reformatted and used to construct a virtual planning of the implants and a guide template in Dental Slice. Six dental implants were placed in the maxilla and mandible using a Slice Guide System. Following a 30-month in maxilla and 24-month in mandible healing period, the clinical and radiographic evaluation and computed tomography (CT) showed good clinical stability. The Slice Guide System proved satisfactory for the Flapless Surgical Technique in dental implants.
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Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. © 2011 American Institute of Physics.
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Deep lipomas, especially in the head and neck region, are uncommon. This report describes the case of a patient with a large intermuscular lipoma of the submandibular space, which had been present for 10 years and was diagnosed by computed tomography. The clinical, imaging, and histopathological features, as well as the management of the tumor, are described.