Processamento de imagens em 3D-TC para análise qualitativa e quantitativa de cistos e tumores maxilo-faciais

The objective of this study was to evaluate spiral-computed tomography (3D-CT) images of 20 patients presenting with cysts and tumors in the maxillofacial complex, in order to compare the surface and volume techniques of image rendering. The qualitative and quantitative appraisal indicated that the volume technique allowed a more precise and accurate observation than the surface method. On the average, the measurements obtained by means of the 3D volume-rendering technique were 6.28% higher than those obtained by means of the surface method. The sensitivity of the 3D surface technique was lower than that of the 3D volume technique for all conditions stipulated in the diagnosis and evaluation of lesions. We concluded that the 3D-CT volume rendering technique was more reproducible and sensitive than the 3D-CT surface method, in the diagnosis, treatment planning and evaluation of maxillofacial lesions, especially those with intra-osseous involvement.O presente trabalho consiste em um estudo associativo e comparativo entre as técnicas de superfície e volume para a reconstrução de imagens em três dimensões (3D) utilizando tomografia computadorizada (TC). Foram realizadas tomografias computadorizadas em espiral de 20 pacientes com cistos e tumores do complexo maxilo-facial para análise qualitativa e quantitativa, utilizando métodos de superfície e de volume em 3D. A comparação interexaminadores apresentou erro padrão percentual menos elevado para a técnica de volume (1,94%) que para a técnica de superfície (4,38%), indicando a maior reprodutibilidade do primeiro método. As medidas obtidas pela técnica de volume foram em média 6,28% mais elevadas que as medidas obtidas pela técnica de superfície. A técnica de volume apresentou sensibilidade mais elevada que a técnica de superfície na identificação das lesões do complexo maxilo-facial. A técnica de volume em 3D-TC, utilizando a metodologia da computação gráfica, apresentou maior reprodutibilidade e sensibilidade para o diagnóstico, planejamento e acompanhamento do tratamento, principalmente das lesões com comprometimento intra-ósseo

Protocolo vascular por meio da 3D-TC utilizando a computação gráfica para avaliação de lesões maxilo-faciais

In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.Neste trabalho, demonstramos os aspectos de um granuloma central de células gigantes por meio da tomografia computadorizada (TC) em espiral baseada na reconstrução de imagem em três dimensões (3D), utilizando a computação gráfica, e a importância do protocolo vascular permitindo um melhor diagnóstico, visualização e obtendo dimensões da lesão. Foram analisados 21 pacientes com lesões maxilo-faciais de origens neoplásicas e proliferativas. Dois radiologistas analisaram as imagens. A utilidade da interação da reconstrução da imagem por meio da computação gráfica, especialmente utilizando o protocolo vascular para análises qualitativas e quantitativas para o diagnóstico, planejamento de tratamento e evolução, assim como para a localização da extensão da lesão foi demonstrada. Isto é um importante adjunto para a evolução destas lesões em relação a cortes axiais em TC e para imagens por meio de 3D-TC para estruturas ósseas

Análise quantitativa dos seios maxilares por meio da tomografia computadorizada

The aim of this study was to evaluate the precision and accuracy of linear measurements of maxillary sinus made in tomographic films, by comparing with 3D reconstructed images. Linear measurements of both maxillary sinus in computed tomography CT of 17 patients, with or without lesion by two calibrated examiners independently, on two occasions, with a single manual caliper. A third examiner has done the same measurements electronically in 3D-CT reconstruction. The statistical analysis was performed using ANOVA (analyses of variance). Intra-observer percentage error was little in both cases, with and without lesion; it ranged from 1.14% to 1.82%. The inter-observer error was a little higher reaching a 2.08% value. The accuracy presented a higher value. The perceptual accuracy error was higher in samples, which had lesion compared to that which had not. CT had provided adequate precision and accuracy for maxillary sinus analyses. The precision in cases with lesion was considered inferior when compared to that without lesion, but it can't affect the method efficacy.O objetivo deste trabalho foi avaliar a precisão e acurácia de medidas lineares da região de seio maxilar realizadas em filmes tomográficos, por meio de comparação com a reconstrução da imagem em 3D. Medidas lineares de ambos os seios maxilares foram realizadas em tomografias computadorizadas (2D-TC) de 17 pacientes, normais e com lesão, por dois examinadores, calibrados, separadamente, duas vezes cada um, utilizando um compasso. Um terceiro observador realizou as mesmas medidas eletronicamente na reconstrução 3D-TC. ANOVA (análise de variância) foi utilizado para análise estatística. A porcentagem de erro intra-examinadores foi pequena em ambos os casos, com ou sem lesão, variando de 1,14% a 1,82%. O erro inter-examinadores foi maior alcançando o valor de 2,08% .O erro percentual de acurácia nas amostras com lesão foram maiores comparando-as às que não tinham lesão. A tomografia computadorizada em 2D-TC (Em filmes e estação de trabalho independente) proporcionou precisão e acurácia adequadas para análise dos seios maxilares. "O erro foi maior no caso de seios maxilares com lesão,comparando aos lados sem lesão, tanto inter quanto intra-examinadores, sem alterar, porém, a eficácia do método.

Evaluation of cone beam computed tomography imaging in placed dental implants: comparison between multiplanar reconstruction and parasagittal images / Avaliação de imagens de tomografia computadorizada de feixe cônico em implantes instalados: comparação entre reconstrução multiplanar e imagens parassagitais

This study aimed to compare multiplanar reconstruction (MPR) to parasagittal images of cone-beam computed tomography (CBCT) for localizing placed dental implants concerning adjacent anatomical structures (nasal fossa floor, maxillary sinus, inferior alveolar canal and nasopalatine canal).The CBCT exams of 164 placed implants were analyzed. All tomographic images were imported to Imaging Studio software to create parasagittal image templates. The images were randomized and analyzed by two oral and maxillofacial radiologists who classified whether or not there was perforation of the anatomical structure in question.According to Kappa coefficient of agreement, the results including, all anatomical structures for inter-observer assessment was 0.81 and for intra-observer assessment, 0.79 for observer one and 0.89 for observer two. For each anatomical structure, the agreement ranged from 'substantial' to 'almost perfect' (nasal fossa floor 0.72, nasopalatine canal 0.92, maxillary sinus 0.81, and inferior alveolar canal 0.81).  Based on our findings, there was substantial to almost perfect agreement when comparing MPR and parasagittal images of CBCT regarding of implant position relationship with anatomical structures. Since both modalities did not differ in implant position, and the MPR represents the complete and original volume that enables analysis in three dimensions, they can be the first-choice imaging modality to analyze placed dental implants

Radiographic imaging pattern of ossifying fibroma mimicking ameloblastoma: a case report

Radiographic examinations complement the anamnesis and physical exam with the purpose of reaching diagnosis, prognosis and treatment planning. In this case report, a 48 year-old male Caucasian patient was referred to an oral and maxillofacial surgeon by a general practitioner after a panoramic radiography for treatment planning; the implant surgery follow-up portrayed a multilocular radiolucent image at the left posterior mandible. Based solely on the panoramic radiography, the diagnostic hypothesis was ameloblastoma. The surgeon decided to perform an incisional biopsy. However, during the procedure, the professional noted that the lesion was easily detached from the adjacent bone and opted for the total removal of the lesion, thus altering its diagnostic hypothesis to central ossifying fibroma (COF). The histopathological result confirmed the diagnostic hypothesis provided by the surgeon, i.e. COF. Although multilocular presentation is not common, COF should be considered in the scope of multilocular radiolucent lesions of the jaws. In addition, computerized tomography imaging exam complemented by surgical and histopathological aspects should be considered for establishing the final diagnosis and conducting the therapeutic approach.Os exames radiográficos complementam a anamnese e o exame físico a fim de estabelecer o diagnóstico, o prognóstico e o planejamento do tratamento. Neste relato de caso, um paciente do sexo masculino, de 48 anos, foi encaminhado a um cirurgião bucomaxilofacial por um clínico geral após uma radiografia panorâmica para o planejamento do tratamento; o seguimento da cirurgia de implante retratou uma imagem radiotransparente multilocular na mandíbula posterior esquerda. Baseado apenas na radiografia panorâmica, a hipótese diagnóstica foi ameloblastoma. O cirurgião decidiu realizar uma biópsia incisional. No entanto, durante o procedimento, o profissional notou que a lesão era facilmente separada do osso adjacente e optou pela retirada total da lesão, alterando sua hipótese diagnóstica para fibroma ossificante central (FCO). O resultado histopatológico confirmou a hipótese diagnóstica do cirurgião, ou seja, o COF. Embora a apresentação multilocular não seja comum, o FCO deve ser considerado em casos de lesões radiotransparentes multiloculares das mandíbulas. Além disso, o exame de tomografia computadorizada complementado por aspectos cirúrgicos e histopatológicos deve ser considerado para estabelecer o diagnóstico final e conduzir a abordagem terapêutica

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

Objective To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT

Osteossarcoma e condrossarcoma: diferenciação radiográfica por meio da tomografia computadorizada

The purpose of this paper was to associate and compare the radiographic patterns of osteosarcoma and those of chondrosarcoma by means of computed tomography (CT). Computed tomographs of five cases of osteosarcoma and five cases of chondrosarcoma of the head and neck region were analyzed. The sensitivity of CT was calculated based on the results of histopathological examinations. We concluded that CT can facilitate the establishment of the final diagnosis since it is possible to distinguish the individual characteristics of osteosarcomas and chondrosarcomas in that exam.A proposta deste trabalho consiste no estudo associativo e comparativo entre os aspectos radiográficos das tomografias computadorizadas de osteossarcomas e de condrossarcomas, com os exames histopatológicos destas lesões. Foram analisadas as tomografias computadorizadas (TC) de 5 pacientes com osteossarcoma e 5 pacientes com condrossarcoma, na região de cabeça e pescoço. A sensibilidade da TC foi calculada a partir da confirmação do exame histopatológico. Concluímos que o padrão radiográfico dos osteossarcomas e condrossarcomas, observado na TC, pode auxiliar e facilitar o diagnóstico final, por meio de características individuais destas lesões que, através do estudo qualitativo, puderam ser identificadas e analisadas

Análise de densidade linear para reparo ósseo em ratos utilizando radiografia digital direta

The objective of this study was to assess bone density measurements for analysis of repairing fractures in rats using direct digital radiography under Dexamethasone effects. Thirty (30) young adult male Wistar rats were used, with an average weight of 200g, which were submitted to general anesthetics by ethyl ether. One rib of each animal was fractured by surgical technique. The rats were divided into 2 groups, named Control group - intraperitoneal administration of saline solution 1 hour prior to operation, and Group 1: intraperitoneal administration of Dexamethasone 0.1mg/Kg of weight 1 hour prior to operation, and two postoperative doses every 12 hours. The animals were sacrificed at 2, 3, 4, 7 and 14 days. The parts containing the hemi-thorax with the fractured rib were removed and submitted to direct digital radiography, where the linear density of the two extremities of the fracture were analyzed by the Digora System. The results showed that in the control group and in Group 1 there was a gradual and significant increase in linear density. The method used made it feasible to supply data that were statistically significant in assessing the gain in bone density during the period of time analyzed. In conclusion, direct digital radiograph is useful for bone density analysis for fracture repairing. The dose of Dexamethasone was not sufficient to alter the gain in bone density at the extremities of fracture.O objetivo deste estudo foi analisar densidade linear utilizando o sistema de radiografia digital direta intrabucal para verificar o ganho de densidade óssea em fraturas de ratos sob os efeitos da Dexametasona. Trinta (30) ratos Wistar machos, adultos jóvens de 200 g em média foram usados. Os animais foram submetidos á anestesia geral por inalação de éter etílico e 01 costela de cada animal foi fraturada através de técnica cirúrgica. Os ratos foram divididos em grupos de 03 repetições para cada grupo em cada período de tempo: Grupo Controle: administração intraperitoneal de soro fisiológico 01 hora antes da intervenção cirúrugica. Grupo 1: administração intraperitoneal de Dexametasona 0.1mg/Kg de peso 01 hora antes da intervenção e duas doses pós operatórias a cada 12 horas. Os animais foram sacrificados com 02, 03, 04, 07 e 14 dias. As partes contendo o hemi tórax da costela com a fratura foram removidas e submetidas aos raios x, onde as imagens foram analisadas através do sistema Digora. Os resultados mostraram que no grupo Controle e no Grupo 1 houve um ganho gradual na densidade linear. O método utilizado para análise forneceu dados estatisticamente significativos durante o período de tempo analisado. Assim concluimos que o método de radiografia dentária digital pode ser utilizado para análise de densidade linear de fraturas. As doses utilizadas de Dexametasona neste experimento não foram suficientes para alterar a densidade óssea no reparo de fraturas em ratos

Computed tomography bone density variations in oncological patients undergoing antiresorptive medication

The purpose of this study was to compare jaw and cervical vertebrae bone density in computed tomography (CT) analyses of oncological patients undergoing antiresorptive medication with control patients, aiming to find information that may assist the radiologist and clinician in predicting risks and monitoring osteonecrosis in the jaw. Thirty-one patients treated with zoledronic acid and 37 control were included in the study. Two areas in regions of interest were chosen and standardized, one in the lower portion of the mandible and another in the axial cervical vertebra (C2) of patients undergoing antiresorptive drug treatment (experimental group) and the control group. Density analysis was performed using Hounsfield scale grayscale values obtained from multislice CT exams. Interclass correlation coefficient test (ICC) was performed to assess reproducibility and repeatability. The test of normality of the samples was demonstrated using the Shapiro-Wilk test and the comparison performed using Mann-Whitney U non-parametric test. When compared to patients in the control group, patients undergoing antiresorptive medication depicted an increase in bone density in both jaw bone (p=0.021) and cervical vertebrae (p=0.002). The same pattern could be observed in patients who used the medication on a monthly basis for analysis of jaw bone (p=0.021), the cervical vertebrae (p=0.002), and the cervical vertebrae of the patients who used the medication on a quarterly basis (p=0.003). CT can be a potentially useful method for detecting alterations associated with antiresorptive therapy, serving as a possible tool in the prediction of the disease progression

Análise de densidade linear para reparo ósseo em ratos utilizando radiografia digital direta

The objective of this study was to assess bone density measurements for analysis of repairing fractures in rats using direct digital radiography under Dexamethasone effects. Thirty (30) young adult male Wistar rats were used, with an average weight of 200g, which were submitted to general anesthetics by ethyl ether. One rib of each animal was fractured by surgical technique. The rats were divided into 2 groups, named Control group - intraperitoneal administration of saline solution 1 hour prior to operation, and Group 1: intraperitoneal administration of Dexamethasone 0.1mg/Kg of weight 1 hour prior to operation, and two postoperative doses every 12 hours. The animals were sacrificed at 2, 3, 4, 7 and 14 days. The parts containing the hemi-thorax with the fractured rib were removed and submitted to direct digital radiography, where the linear density of the two extremities of the fracture were analyzed by the Digora System. The results showed that in the control group and in Group 1 there was a gradual and significant increase in linear density. The method used made it feasible to supply data that were statistically significant in assessing the gain in bone density during the period of time analyzed. In conclusion, direct digital radiograph is useful for bone density analysis for fracture repairing. The dose of Dexamethasone was not sufficient to alter the gain in bone density at the extremities of fracture.O objetivo deste estudo foi analisar densidade linear utilizando o sistema de radiografia digital direta intrabucal para verificar o ganho de densidade óssea em fraturas de ratos sob os efeitos da Dexametasona. Trinta (30) ratos Wistar machos, adultos jóvens de 200 g em média foram usados. Os animais foram submetidos á anestesia geral por inalação de éter etílico e 01 costela de cada animal foi fraturada através de técnica cirúrgica. Os ratos foram divididos em grupos de 03 repetições para cada grupo em cada período de tempo: Grupo Controle: administração intraperitoneal de soro fisiológico 01 hora antes da intervenção cirúrugica. Grupo 1: administração intraperitoneal de Dexametasona 0.1mg/Kg de peso 01 hora antes da intervenção e duas doses pós operatórias a cada 12 horas. Os animais foram sacrificados com 02, 03, 04, 07 e 14 dias. As partes contendo o hemi tórax da costela com a fratura foram removidas e submetidas aos raios x, onde as imagens foram analisadas através do sistema Digora. Os resultados mostraram que no grupo Controle e no Grupo 1 houve um ganho gradual na densidade linear. O método utilizado para análise forneceu dados estatisticamente significativos durante o período de tempo analisado. Assim concluimos que o método de radiografia dentária digital pode ser utilizado para análise de densidade linear de fraturas. As doses utilizadas de Dexametasona neste experimento não foram suficientes para alterar a densidade óssea no reparo de fraturas em ratos.31732