Valor diagnóstico da ressonância magnética na análise do ameloblastoma: relato de dois casos

Ameloblastoma is an odontogenic tumor that shares clinical and imaging characteristics with other lesions of the jaws, such as odontogenic keratocyst, which makes the diagnosis difficult.However, in addition to radiographic and tomographic examinations, Magnetic Resonance Imaging (MRI) has been increasingly used, contributing with relevant additional information about thedifferentiation between solid and liquid components of the lesion. This case report was conducted to present two variations of ameloblastoma and discuss the radiographic, tomographic and MRI contribution in the differential diagnosis between ameloblastoma and odontogenic keratocyst. The signal intensity in T1-weighted MRI revealed internal fluid content in both cases, which was important in the differential diagnosis with other intraosseous lesions such as odontogenic keratocysts. This is probably due to the presence of keratin that increases the viscosity of the content and also for an intermediate signal intensity signal in T2-weighted MRI. Therefore, MRI revealed important internal characteristics of the reported lesions, which was very useful in the establishment of the differential diagnosis with other lesions223425431O ameloblastoma é um tumor odontogênico que compartilha características clínicas e de imagem com outras lesões da mandíbula, como o ceratocisto odontogênico, o que dificulta o seu diagnóstico. Entretanto, além dos exames radiográficos e tomográficos, a ressonância magnética (RM) tem sido cada vez mais utilizada, contribuindo com informações adicionais relevantes sobre a diferenciação entre componentes sólidos e líquidos da lesão. Este relato de caso apresenta duas variações de ameloblastoma e discuti a contribuição radiográfica, tomográfica e da RM no diagnóstico diferencial entre o ameloblastoma e o ceratocisto odontogênico. A RM ponderada em T1 revelou conteúdo líquido interno em ambos os casos relatados, o que foi importante no diagnóstico diferencial com outras lesões intraósseas, como os ceratocistos odontogênicos. Isto ocorre devido à presença de queratina aumentar a viscosidade do conteúdo e também gerar um sinal de intensidade intermediária na RM ponderada em T2. Portanto, a RM revelou importantes características internas das lesões relatadas, o que foi muito útil no estabelecimento do diagnóstico diferencial com outras lesõe

Evaluation measure of 3d volumetry of masseter hypertrophy: association with modalities of imaging

Masseteric hypertrophy is a benign condition, asymptomatic and rare, characterized by the excessive development of the masseter muscle, which usually results in aesthetic complaints. The imaging exams for differential diagnosis of pathologies in the parotid-masseteric region is always recommended. This work aims the imaging characterization of masseteric hypertrophy through the report of two clinical cases combining different imaging modalities: panoramic radiography, magnetic resonance imaging, computed tomography, ultrasonography and 3D volumetry. Two male subjects with no family history of masseteric hypertrophy were referred to a diagnostic center in dentomaxillofacial radiology due to an increase in bilateral facial volume in the masseteric region. Images of the panoramic radiography showed an increase of the bilateral mandibular angle in both cases. Using computerized tomography, bilateral masseter muscle hypertrophy was demonstrated in the patients, and magnetic resonance scan and ultrasound examination were performed for better visualization and muscle measurement. 3D volumetry assessment of musculature showed as additional tool to evaluate the status of the masseter muscles in patients with Masseteric hypertrophy. Therefore, the association of imaging examinations allowed to perform the imaging characterization of masseteric hypertrophy with presence of bone exostosis