A Real-time Reconstruction Method of CBCT Short Scan Based on Attenuation Compensation / 中国医疗器械杂志

Aiming at the problem of timeliness of CBCT reconstruction, a CBCT fast short scan reconstruction method is proposed. At the same time, the image reconstruction process in which a new attenuation compensation algorithm is applied to improve image quality. When performing FDK three-dimensional reconstruction of a single-frame acquisition image, the Parker-weighted image is calculated in real time, and a new attenuation compensation algorithm is applied in the back projection process to complete the short scan Parker-weighted reconstruction. This method simulates the CBCT synchronous acquisition and reconstruction process by establishing collection and reconstruction threads. Under the premise of satisfying the reconstruction quality, the reconstruction can be completed within 1 to 2 seconds after the patient collection is completed, which achieves the purpose of real-time.

Influence of skeletal class and facial type on nose dimensions in a Brazilian subpopulation: a CBCT study

Abstract: Evaluating factors that may influence the nose dimensions and, therefore, contribute to the singularity of a person, is important for obtaining a precise facial reconstruction (FR) in forensic anthropology. Thus, the aim in this study was to evaluate the influence of sex, skeletal class, and facial type on nose dimensions of Brazilian individuals using cone-beam computed tomography (CBCT) scans. CBCT images of 54 males and 67 females were classified according to skeletal class (class I, II, or III) and facial type (brachycephalic, dolichocephalic and mesocephalic). Linear and angular measurements of the nose were performed using the CS 3D Imaging software. The measurements obtained for males and females were compared by one-way ANOVA. Two-way ANOVA was used to compare the measurements in the different skeletal classes and facial types. Significance level was set at 5%. All linear measurements were greater in males (p < 0.05); the angular measurements, however, did not differ between sexes (p > 0.05). Linear and angular measurements of class III males were significantly different from the other classes; the same was observed for the angular measurements in females (p < 0.05). Regarding facial types, some linear measurements were significantly greater in dolichocephalics males (p < 0.05). For females, there was no influence of facial type (p > 0.05), except for the nasal convexity angle. Nose dimensions differed in specific points among different skeletal classes and facial types, and there was sexual dimorphism in all linear nose dimensions. This information may be applicable for nose reconstructions, allowing more reliable FR.

Incisor root length in individuals with and without anterior open bite: a comparative CBCT study

ABSTRACT Objective: This study aimed to compare the root length of maxillary and mandibular incisors between individuals with open bite versus matched individuals with adequate overbite. Methods: This comparative, matched and retrospective study included 48 cone beam computed tomographies (CBCTs) obtained at a university radiological center. Scans belonged to 24 individuals with open bite (overbite ≤ 0 mm) and 24 individuals with adequate overbite (controls). Both groups were matched by age, sex, malocclusion classification and skeletal characteristics (ANB and FMA angles). Root length of each maxillary and mandibular incisor was measured in millimeters (mm) in a sagittal section from a perpendicular line to the enamel cement junction until the root apex (384 length measurements were made). The means of root length in both groups were compared using t-tests. In addition, correlations between variables were evaluated with the Pearson correlation coefficient (α = 0.05). Results: In both groups, the root length of the upper central incisors was approximately 12 mm and the root length of the maxillary lateral incisors was approximately 13 mm (p˃ 0.05). Likewise, the root length of lower central incisors in both groups measured approximately 12 mm (p˃ 0.05). However, the mandibular lateral incisor roots of open bite patients were significantly longer than in the normal overbite patients (approximately 1 mm, p= 0.012 right side, p= 0.001 left side). Conclusions: Root length of maxillary incisors and central mandibular incisor is similar in individuals with or without open bite, but the mandibular lateral incisor roots in open bite patients were significantly longer than in the normal overbite patients.

RESUMO Objetivo: O presente estudo teve como objetivo comparar o comprimento radicular de incisivos superiores e inferiores em indivíduos com mordida aberta versus indivíduos com sobremordida normal. Método: Esse estudo comparativo e retrospectivo incluiu 48 tomografias computadorizadas de feixe cônico (TCFC) obtidas em um centro radiológico universitário. As tomografias foram realizadas em 24 indivíduos com mordida aberta (sobremordida ≤ 0 mm) e 24 indivíduos com sobremordida normal (controle). Ambos os grupos foram compatibilizados de acordo com a idade, sexo, má oclusão e padrão esquelético (ângulos ANB e FMA). O comprimento radicular de todos os incisivos superiores e inferiores foi medido em milímetros (mm) em um corte sagital, de uma linha perpendicular à junção cemento-esmalte até o ápice radicular (384 medidas de comprimento foram realizadas). A média de comprimento radicular em ambos os grupos foi comparada utilizando-se o teste t. Adicionalmente, correlações entre as variáveis foram avaliadas usando o coeficiente de correlação de Pearson (α = 0,05). Resultados: Em ambos os grupos, o comprimento radicular dos incisivos centrais superiores foi de, aproximadamente, 12 mm, e o comprimento radicular dos incisivos laterais superiores foi de, aproximadamente, 13 mm (p˃ 0,05). Da mesma forma, o comprimento radicular dos incisivos centrais inferiores, em ambos os grupos, obteve a medida de aproximadamente 12 mm (p>0,05). No entanto, o comprimento radicular dos incisivos laterais inferiores em indivíduos com mordida aberta foi significativamente maior em comparação aos pacientes com sobremordida normal (aproximadamente 1 mm, p=0,012 do lado direito, p=0,001 do lado esquerdo). Conclusões: O comprimento radicular de incisivos superiores e incisivos centrais inferiores foi similar em indivíduos com ou sem mordida aberta, mas o comprimento radicular de incisivos laterais inferiores em indivíduos com mordida aberta foi significativamente maior em comparação a pacientes com sobremordida normal.

Prevalence of soft tissue calcifications in cone beam computed tomography images in the region of head and neck / Prevalência de calcificações de tecidos moles em exames de tomografia computadorizada de feixe cônico

Objective: to evaluate the prevalence of calcifications in the soft tissues of the cervical-facial region using cone beam computed tomography (CBCT) images. Material and Methods: two hundred and ten CBCT exames was analyzed by 01 examiner previously trained, with fild of view (FOV) of 16 x 13 cm and voxel of 0.25 mm, in ICAT Vision software (Imaging Science International, Hatfield, PA, USA) in coronal, axial and sagittal sections. The following calcifications were evaluated: tonsiloliths, sialolites, calcification of the styloid complex, calcified carotid atheromas, calcifications in laryngeal cartilages, calcified lymph nodes and osteoma cutis. The findings were tabulated according to the total of the sample, related to the gender, age group of the individuals. Results: Calcification of the styloid complex was the most frequent in the sample studied in both genres (39.04%), followed by the presence of tonsiloliths (19.52%), and calcified lymph nodes (6,67%). Conclusion: calcifications are frequent radiographic findings in CBCT and important for the diagnosis of some possible pathologies that do not present clinical symptoms (AU)

Objetivo: avaliar por meio de imagens de tomografia computadorizada de feixe cônico (TCFC) a prevalência de calcificações em tecidos moles da região cérvicofacial. Material e Métodos: os exames foram avaliados por um examinador, previamente treinado que avaliou 210 exames de TCFC, com campo de visão (FOV) de 16 x 13 cm e voxel de 0,25 mm. Os exames foram avaliados no software ICAT Vision (Imaging Science International, Hatfield, PA, Estados Unidos da América) em cortes coronais, axiais e sagitais. As seguintes calcificações foram avaliadas: tonsilolitos, sialolitos, calcificação do complexo estiloide, ateromas da carótida calcificados, calcificações na cartilagens laríngeas, nódulos linfáticos calcificados e osteoma cútis. Os achados foram tabulados de acordo com o total da amostra, relativos ao gênero e faixa etária dos indivíduos. Resultados: a calcificação do processo estiloide foi a mais frequente na amostra estudada em ambos os sexos, seguido da presença dos tonsilolitos e linfonodos calcificados. Conclusão: as calcificações de tecidos moles são achados radiográficos frequentes na TCFC e importantes para diagnósticos de algumas possíveis patologias que não apresentam sintomatologia clínica.(AU)

El paciente ortodóncico en dentición mixta y los trastornos del sueño / The orthodontic patient with mixed dentition and sleep disorders

Los desórdenes respiratorios del sueño (DRS) y, principalmente, roncopatías y apneas obstructivas afectan aproximadamente al 7% de los pacientes ortodóncicos. Los DRS no solo son importantes por la cantidad de pacientes afectados, sino por la gravedad de los posibles efectos secundarios a nivel de la salud general del paciente. La obstrucción de las vías aéreas superiores (VAS) provoca alteraciones del crecimiento y deformaciones craneofaciales importantes, por lo que el tratamiento temprano y la prevención de la respiración oral es muy importante.El papel del ortodoncista es muy importante en el diagnóstico y en el tratamiento de los DRS, pero también en su prevención, realizando tratamientos que aumenten la dimensión y la permeabilidad de las VAS. El protocolo de exploración interdisciplinar en niños y adolescentes y la cefalometría de vías aéreas son importantes en el diagnóstico y deben ser tenidos en cuenta en el plan de tratamiento. Pero las pruebas más significativas, el CBCT de vías aéreas y la polisomnografía no son pruebas rutinarias por la dificultad logística y el precio de estas pruebas. En este artículo también se recomiendan los tratamientos de ortodoncia más indicados en estos casos y que tienden al aumento de la dimensión de las VAS (AU)

Sleep breathing disorders (SBD) and in the first place, roncopathy and obstructive apnea, affect approximately 7% of orthodontic patients. The SBD are not only important for the number of affected patients, but also for the severity of the possible side effects at the level of general health of a patient. The upper air ways (UAW) obstruction provokes important alterations in growth and craniofacial deformations, and this is why the early treatment and prevention of mouth breathing are very important. The role of an orthodontist in diagnosis and treatment of SBD is very important, but it is also in its prevention, carrying out the treatments which increase the dimension and permeability of UAW. The protocol of interdisciplinary examination.In children and adolescents and the air ways cephalometry analysis have an important role in diagnosis and they should be taken into account in treatment planning. But the most important tests, the air ways CBCT and polysomnography, are not routine tests due to the complicated logistics and their cost. In this article, the orthodontic treatments most indicated in these cases are recommended, because they tend to increase the UAW dimension (AU)

Estudo comparativo do vidro bioativo e osso autógeno em aumento do assoalho de seios maxilares de humanos / Comparative study of bioactive glass and autogenous bone graft in human maxillary sinus augmentation

A deficiência óssea vertical do seio maxilar impossibilita a instalação de implantes dentais necessários para a reabilitação protética contudo, técnicas cirúrgicas para a elevação da membrana sinusal e o uso dos biomateriais para enxertia óssea permitiram alterar esta condição. O ósseo autógeno é considerado o mais previsível e o padrão ouro para tal finalidade porém, biomateriais como o vidro bioativo, amplamente utilizado na odontologia, permitem substituí-lo. O objetivo deste estudo foi avaliar formação óssea, o comportamento celular e a taxa de reabsorção do vidro bioativo em 2 proporções: puro (grupo 1); adicionado ao osso autógeno 1:1 (grupo 2), comparando com o osso autógeno (grupo 3) em seios maxilares de humanos. Com 15 dias de operados os pacientes realizaram um tomografia computadorizada (TC) cone beam para determinar o volume inicial do enxerto (T1). Após 6 meses uma nova TC foi realizada determinando o volume ósseo final (T2) e também, a coleta das biópsias com a instalação simultânea de implantes dentais. As amostras foram divididas em 3 áreas: leito, intermediária e apical onde foram avaliadas a histomorfometria e imunomarcações para Runx2, VEGF, osteocalcina e TRAP. No grupo 1 os resultados foram de 42.6%, 44.5% e 48% de formação óssea no leito, intermediária e apical respectivamente. No grupo 2 as taxas encontradas foram de 36.6% no leito, 33.2% na intermediária e 45.8% na apical. No grupo 3 foi de 34.4% para o leito, 35.0 na intermediária e 42.0% na apical. (p>0.05) Os 3 grupos apresentaram-se com comportamento semelhante nas imunomarcações realizadas mostrando estar maturado e calcificado o suficiente para receber implantes dentais. As taxas de reabsorção também mostraram-se semelhantes com 44.2% para o grupo 1, 37.9% para o grupo 2 e 45.7% no grupo 3. (p>0.05) Assim, podemos concluir que o vidro bioativo possui resultados equiparados ao osso autógeno(AU)

Vertical bone deficit due maxillary sinus pneumatization forbid the dental implants placement required for prosthetic rehabilitation however, surgical techniques to elevate maxillary sinus membrane and studies about biomaterials, allows repair these situation. Autogenous bone graft is considered the most predictable and the gold standard for this nevertheless, biomaterials as bioactive glass, has been widely used in dental surgery and allows substitute it. The aim of this study was evaluate the bone formation, the cellular behavior and the resorption rates of bioactive glass in 2 proportions: pure (group 1); add to autogenous bone graft (group 3), comparing then with autogenous bone graft in human maxillary sinus. Post-operative cone beam computed tomography (CT) was used to measure the initial graft volume after 15 days (T1). Six months later, another CT was performed to evaluate the final graft volume (T2) and determine the graft resorption rate and the harvest of biopsies with dental implants placement simultaneously. The samples were divided in 3 areas: bed, intermediately and apical which were evaluated to histomorphometric and immunostaining to Runx2, VEGF, osteocalcin and TRAP. In group 1 the bone formation were 42.6%, 44.5 and 48.0% for bed, intermediately and apical respectively. In group 2 the rates were 36.6% in bed, 33.2% in intermediately and 45.8% in apical. In group 3 were 34.4% in bed, 35.0% in intermediately and 42.0% in apical. (p>0.05) the 3 groups had the same behavior for the 4 proteins showing be matured and calcified to receive dental implants. The resorption rates were similar for the 3 groups with 44.2% % for group 1, 37.9% for group 2 and 45.7% for group 3. (p>0.05) In conclusion, the bioactive glass is a good substitute to autogenous bone graft in both proportions evaluated(AU)

Three Cases of Nodular Fasciitis in the Parotid Gland / 대한이비인후과학회지

Nodular fasciitis (NF) is a benign tumor-like fibroblastic proliferation, and there have only been few reports about NF involving the parotid gland. Here, we report our experience of three cases of NF in the parotid gland, as well as our evaluation of the diagnostic tools for NF in the parotid gland, such as fine-needle aspiration cytology (FNAC), CT, and clinicopathologic investigations. In the three cases observed, all had growing masses in the parotid gland, and the lesions showed heterogeneous or peripheral rim enhancement on the contrast-enhanced CT, which could have been misdiagnosed as parotid malignancy. On FNAC, the cells had an elongated spindle shape and contained variable amounts of stromal matrix, which could have caused misinterpreted as pleomorphic adenoma. We observed dense cellularity and varying amounts of collagenous stroma, and immunohistochemical staining revealed positive reactivity to CD10, CD34, and smooth muscle actin. NF should be considered in the differential diagnosis of benign and malignant parotid tumors.

Tomografia computadorizada de feixe cônico como método de diagnóstico auxiliar na localização de canais calcificados / Cone beam computed tomography as a diagnostic method assist in locating calcified canals

Introdução: novos instrumentos e meios de diagnóstico estão surgindo com o objetivo de facilitar e otimizar o tratamento endodôntico. A tomografia computadorizada de feixe cônico apresenta-se como uma nova ferramenta para o endodontista diagnosticar reabsorções e fraturas radiculares, e localizar canais não visualizados na radiografia convencional. Aliada a essa nova tecnologia, limas rotatórias de uso único, utilizadas no movimento reciprocante, estão sendo cada vez mais difundidas na Endodontia. Objetivo: descrever um caso clínico, realizado por meio do uso de lima única (RECIPROC), onde a tomografia computadorizada de feixe cônico foi solicitada para localização de canais calcificados

Avaliação tomográfica da reabsorção radicular apical e das alterações no tecido periodontal de suporte induzidas pelo aparelho Herbst / Tomography evaluation of apical root resorption and changes in periodontal tissue support induced by Herbst appliance

Este estudo avaliou quantitativamente altura e espessura óssea alveolar nos incisivos centrais e laterais inferiores e reabsorção radicular apical em todas as raízes, após uso do aparelho Herbst. Amostra composta por 23 indivíduos brasileiros (11 gênero masculino e 12 gênero feminino), média de idade 15,76 ± 1,75, má oclusão Classe II divisão 1, tratados com Herbst. Tomografias computadorizadas de feixe cônico (TCFC) foram realizadas antes e após o tratamento com Herbst. A altura e a espessura óssea alveolar dos incisivos inferiores foram avaliadas. As espessuras ósseas vestibular (V), lingual (L) e total (T) foram mensuradas nos terços cervical (1), médio (2) e apical (3) dos incisivos inferiores. A reabsorção radicular apical foi determinada pelo método da navegação axial guiada nas imagens de TCFC. O Teste t de Student e o Teste T de Wilcoxon compararam as amostras dependentes nos casos paramétricos e não paramétricos, respectivamente. Os resultados foram considerados para um nível de significância de 5%. Os incisivos inferiores não apresentaram diferença estatística significante para a altura óssea alveolar. A espessura óssea alveolar dos incisivos inferiores reduziu significativamente após o tratamento em V1, V2, V3, T1 e aumentou em L2. A reabsorção radicular apical foi detectada pela TCFC em 57,96% das 980 raízes avaliadas. A TCFC, por permitir a avaliação tridimensional das raízes dentárias, demonstrou que o aparelho Herbst induz reabsorção radicular apical suave, principalmente nos dentes de ancoragem, e o deslocamento dentário induzido por esse aparelho causa redução da espessura óssea alveolar vestibular nos incisivos inferiores.

This study evaluated quantitatively, alveolar bone height and thickness in the central and lateral lower incisors and apical root resorption in all roots after using Herbst appliance. The sample comprised 23 patients (11 men, 12 women), mean ages 15.76 ± 1.75 years, presenting class II division 1, treated with Herbst appliance. Cone-beam computed tomography (CBCT) images were obtained before and after Herbst treatment. The vertical alveolar bone level and the alveolar bone thickness of lower incisors were assessed. Vestibular (V), lingual (L) and total (T) bone thicknesses were assessed at the crestal (1), midroot (2) and apical (3) levels of the lower incisors. The apical root resorption was determined using axial guided navigation of CBCT images. The Student's t-Test and Wilcoxon t-Test were used to compare dependent samples in parametric and non-parametric cases, respectively. The results were considered at a significance level of 5%. The lower incisors showed no statistical significance for the vertical alveolar bone level. The alveolar bone thickness of lower incisors significantly reduced after the treatment at V1, V2, V3, T1 and significantly increased at L2. Apical root resorption was detected by CBCT in 57.96% of 980 roots that underwent treatment. The CBCT, for allowing three-dimensional evaluation of dental roots, showed that Herbst appliance induces mild apical root resorption, mostly in the anchoring teeth, and the tooth movement induced by this appliance causes alveolar bone reduction on the vestibular side of lower incisors

Three-dimensional imaging modalities in endodontics

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

Precisão de medições lineares em tomografias computadorizadas por feixe cônico e helicoidal, realizadas em mandíbulas humanas / Accuracy of linear bone measurements cone-beam and spiral computed tomography in human mandibles

Introdução: a obtenção de métodos de imagem capazes de reproduzir com adequada precisão as dimensões maxilomandibulares é de vital importância para o diagnóstico e o planejamento seguro de procedimentos cirúrgicos. Objetivo: verificar, in vitro, a precisão de medições lineares de um exame de tomografia computadorizada helicoidal e de dois sistemas de tomografia computadorizada por feixe cônico. Método: dez mandíbulas humanas secas foram submetidas a três diferentes exames de tomografia: CBCT i-CAT, CBCT NewTom 3G e HCT helicoidal Picker CT Twin Flash. As medições realizadas diretamente na mandíbula foram feitas com um paquímetro digital, e as tomográficas por meio do software ImplantViewer 2.604. Foram mensuradas seis regiões de cada mandíbula seca, sendo agrupadas em duas regiões de primeiro molar inferior (Sítio PMI), duas regiões de primeiro pré-molar inferior (Sítio PPMI) e em duas regiões de incisivo lateral inferior (Sítio ILI). Resultados: nos sítios ILI e PPMI, as três tomografias estudadas demonstraram precisão semelhante entre si. No sítio PMI, a CBCT i-CAT mostrou-se mais precisa que as dos demais sistemas. Conclusão: pode-se concluir que nos sítios ILI e PPMI as três TCs estudadas apresentam limites de concordância e de precisão semelhantes, e que no sítio PMI a CBCT i-CAT apresentou um limite de concordância de menor amplitude, sendo mais precisa que a dos demais exames.

Availability of imaging methods able to accurately reproducing the maxillo-mandibular dimensions is important for diagnosis and safe planning of surgical procedures. Aim: The aim of this in vitro study was to verify the accuracy of linear measurements in images obtained with a system of spiral and two systems of cone-beam computed tomography (CT). Methods: Ten dry human mandibles were subjected to three different CT scans: I-Cat® CBCT, NewTom-3G® CBCT, and Picker® SCT. Measurements in the mandible were made with a digital caliper and measurements in the images were made with the ImplantViewer® software. Six regions were measured in each dry mandible, being distributed into two regions in each of the lower first molar (LFM), lower first pre-molar (LFPM), and lower lateral incisor (LLI) sites. Results: Similar accuracy was observed among the three images at sites LLI and LFPM. Measurements obtained with the I-Cat CBCT scan at site LFM were shown to be more accurate than the those obtained with the other two CT scan systems. Conclusions: It can be concluded that the three CTs studied herein showed similar limits of agreement and precision at sites LLI and LFPM, and I-Cat CBCT showed limits of agreement with smaller amplitude and greater accuracy than other examinations performed at site LFM. Conclusion: It can be concluded that the three CTs studied herein showed similar limits of agreement and precision at sites LLI and LFPM, and ICat CBCT showed limits of agreement with smaller amplitude and greater accuracy than other examinations performed at site LFM.

Estudio de las venas de la fosa cubital a través de la tomografía computada helicoidal y su aplicación clínica / Study of the veins of the cubital fossa by helical computed tomography and its clinical application

Las venas superficiales de la fosa cubital, constituyen uno de los sitios más importantes de punción venosa. La disposición de estas venas presenta numerosas variaciones. Su anatomía no ha sido estudiada aplicando los avances tecnológicos en el campo de la medicina, como la tomografía computada helicoidal. Fueron analizadas mediante tomografía axial computada helicoidal, las formaciones venosas de la fosa cubital en 60 individuos chilenos de ambos sexos, de edades entre 10 y 86 años, de la IX Región de La Araucanía, Chile. El estudio fue realizado en un tomógrafo General Electric, modelo CT/e, perteneciente al Centro de Imagenología del Hospital del Trabajador, Temuco, Chile, en individuos ambulatorios. Basados en la clasificación de del Sol et al. (1988) para las formaciones venosas de la fosa cubital, se obtuvo los siguientes resultados: Tipo I (46,7 por ciento), la vena cefálica del antebrazo (VCA), se divide en vena mediana basílica (VMB) y vena mediana cefálica (VMC), las que se unen a la vena basílica del antebrazo (VBA) y vena cefálica del accesoria del antebrazo (VCAA), respectivamente. Tipo II (13,3 por ciento), la VCA originó la vena mediana del codo (VMCo), que se une a la VBA. Tipo III (20 por ciento), no existe comunicación entre la VBA y VCA a nivel de la fosa cubital. Tipo IV (8,3 por ciento), la VCA drenaba en la VBA. Tipo V (11,7 por ciento). Otras disposiciones, donde se incluye la "M" clásica, que resulta de la división de la vena mediana del antebrazo. La utilización de la VMC o de la VCA, se recomienda ya que previene los riesgos de punción de otras estructuras anatómicas importantes como el ramo anterior del nervio cutáneo antebraquial medial.

The superficial veins of the cubital fossa, is one of the most important sites of venipunctures. There are many variations in the arrangement of these veins. Their anatomy has not been studied using technology available in the field of medicine such, as helical computed tomography. The vein formation of the cubital fossa in 60 Chilean subjects of both sexes, between 10 and 86 years of age of the IX Region of Araucania, Chile, were analyzed by helical computed tomography. The study was realized on a General Electric scanner, model CT / e, belonging to the Imaging Center of the Hospital del Trabajador, Temuco, Chile, in ambulatory subjects. Based on the classification of del Sol et al. (1988) for the vein formation of the cubital fossa, we obtained the following results: Type I (46.7 percent), the cephalic vein of forearm (CVF), is divided into median basilic vein (MBV) and median cephalic vein (MCV), then anastomosis the basilic vein of forearm (BVF) and cephalic vein accessory (CVA), respectively. Type II (13.3 percent), the CVA originates at the median cubital vein (MCuV), which anastomoses to the BVF. Type III (20 percent), there is no communication between BVF and CVF at the cubital fossa. Type IV (8.3 percent), CVF drains into the BVF. Type V (11.7 percent) - Other disposition, which include the "M" classical, resulting from the division of the median antebrachial vein. Using the MCV or CVF, is recommended, since there are risks of puncture of other important anatomical structures such as the anterior branch of the medial antebrachial cutaneous nerve.

Compute tomography-based quantitative evaluation of pneumoconiosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the value of compute tomography (CT)-based quantitative assessment in the diagnosis of pneumoconiosis.</p><p><b>METHODS</b>Sixty patients with pneumoconiosis and 40 healthy volunteers (control) underwent CT scanning at the levels of the top of the aortic arch, tracheal carina, and 3 cm and 6 cm below the tracheal carina. All the CT images were analyzed with density histograms for a specific region to calculate the mean lung CT value (ME) and pixel index for assessment of lung density changes.</p><p><b>RESULTS</b>At the levels of the top of the aortic arch and 6 cm below the tracheal carina, the pixel indices in the 10 CT threshold density intervals within -832 to -352 HU was all significantly higher in pneumoconiosis group than in the control group (P<0.05). At the levels of the tracheal carina and 3 cm below the tracheal carina, the 11 pixel indices in the CT threshold density intervals within -880 to -352 HU were also significantly higher in pneumoconiosis group (P<0.05). At all the 4 scan levels, the pixel indices in the 10 intervals between -880 and -352 HU were all significantly higher in pneumoconiosis group (P<0.05).</p><p><b>CONCLUSION</b>CT density histograms allow quantitative evaluation of lung fibrosis in patients with pneumoconiosis for diagnostic purposes.</p>

[Comparison of absorbed skin dose received by patients in cone beam computed tomography, spiral and conventional computed tomography scanning]

The evaluation of absorbed dose received by patients could give useful information for radiation risk estimation. This study was performed to compare the entrance skin dose received by patients in cone beam computed tomography [CBCT], conventional and spiral computed tomography [CT]. In this experimental study, 81 calibrated TLD chips were used. The TLD chips were placed on facial, thyroid and end of sternum skin surface in patients referred for CT of the paranasal sinuses [3 TLD chips for each area] to estimate the absorbed dose received by central part of radiation field, thyroid and out of field areas, respectively. The data were analyzed using one-way ANOVA and Tukey tests. The dose delivered to the center of irradiated field was about 0.79 +/- 0.09 mGy in CBCT technique compared with 16.31 +/- 3.71 and 18.84 +/- 4.12 mGy for spiral and conventional CT, respectively. The received dose by the out of field areas was about 54 percent of central area dose. There was statistical significant relationship between the imaging modalities and absorbed dose received by patients [P=0.016]. The least absorbed dose was for CBCT and the greatest dose was for conventional CT imaging technique. The dose delivered to central area of irradiated field in conventional and spiral CT imaging modalities was about 24 times greater than of that in CBCT. Also, the highest received dose was for central areas of radiated field and the lowest dose was for the out of field areas

Padronização de um método para mensuração das tábuas ósseas vestibular e lingual dos maxilares na Tomografia Computadorizada de Feixe Cônico (Cone Beam) / Method standardization of buccal and palatal arch bone plate measurement using Cone Beam Computed Tomography

INTRODUÇÃO: a espessura das tábuas ósseas que recobrem os dentes por vestibular e lingual constitui um dos fatores limitantes da movimentação dentária. O avanço tecnológico em Imaginologia permitiu avaliar detalhadamente essas regiões anatômicas por meio da utilização da tomografia computadorizada de feixe cônico (TCFC). OBJETIVO: descrever e padronizar, pormenorizadamente, um método para mensuração das tábuas ósseas vestibular e lingual dos maxilares nas imagens de tomografia computadorizada de feixe cônico. METODOLOGIA: a padronização digital da posição da imagem da face deve constituir o primeiro passo antes da seleção dos cortes de TCFC. Dois cortes axiais de cada maxilar foram empregados para a mensuração da espessura do osso alveolar vestibular e lingual. Utilizou-se como referência a junção cemento-esmalte dos primeiros molares permanentes, tanto na arcada superior quanto na inferior. RESULTADOS: cortes axiais paralelos ao plano palatino foram indicados para avaliação quantitativa do osso alveolar na maxila. Na arcada inferior, os cortes axiais devem ser paralelos ao plano oclusal funcional. CONCLUSÃO: o método descrito apresenta reprodutibilidade para utilização em pesquisas, assim como para a avaliação clínica das repercussões periodontais da movimentação dentária, ao permitir a comparação de imagens pré e pós-tratamento.

INTRODUCTION: The thickness of the buccal and lingual bone plates constitutes one of the limiting factors of the orthodontic movement. The imaging technology has permitted the evaluation of this anatomical region, by means of cone beam computed tomography. PURPOSE: To describe and standardize, in details, a method for measuring the buccal and lingual bone plate thickness in CBCT images. METHODOLOGY: Digital standardization of face image should constitute the first step before the selection of CBCT slices. Two axial sections of each jaw were used for measuring the thickness of buccal and lingual bone plates. The cemento-enamel junction of the first permanent molars was used as a reference, both in the upper and lower arches. RESULTS: Axial sections parallel to the palatine plane were recommended for quantitative evaluation of the alveolar bone plate in the maxilla. In the mandibular arch, the axial sections should be parallel to the functional occlusal plane. CONCLUSION: The method described shows reproducibility for evaluating the periodontal effects of tooth movement for clinical or researching purposes, permitting the comparison between pre and post-treatment images.

Ressonância magnética cardiovascular e tomografia computadorizada cardiovascular nas doenças não-coronárias / Role of cardiovascular magnetic resonance and computed tomography in noncoronary diseases

A tomografia computadorizada e, principalmente, a ressonância magnética cardiovascular têm se mostrado de utilidade cada vez maior para a avaliação de doenças cardiovasculares não-isquêmicas. A alta resolução tanto espacial como temporal desses métodos possibilita a aquisição de imagens com grande detalhamento anatômico, permitindo a avaliação da relação espacial entre estruturas adjacentes de forma não-invasiva. A tomografia tem particular importância para a análise vascular e é o melhor método para detecção de calcificações. No entanto, tem a desvantagem de utilizar contraste iodado e radiação ionizante, de não apresentar alta resolução de contraste entre as estruturas, e de adquirir imagens predominantemente estáticas. A ressonância magnética, por sua vez, é um método que não utiliza radiação ionizante e, por meio de diversas sequências de pulsos e técnicas de aquisição de imagens, é capaz de fornecer, além do detalhamento anatômico...

Elimination of direct derivative of the projection data for image reconstruction based on hybrid filter in helical cone-beam CT / 南方医科大学学报

<p><b>OBJECTIVE</b>We present an alternative approach for precise reconstruction of the images from helical cone-beam projections combining Hilbert filter and Ramp filter.</p><p><b>METHODS</b>Based on the Katsevich algorithm framework, the proposed algorithm combined the FDK-type algorithms and Katsevich algorithm for their respective advantages, to completely avoid the direct derivatives with respect to the coordinates on the detector plane.</p><p><b>RESULTS</b>The experimental results validated the accuracy of the new algorithm, and this approach significantly improved the resolution of the reconstructed images with much reduced artifacts.</p><p><b>CONCLUSION</b>The proposed reconstruction formula based on hybrid Hilbert-Ramp filter is an important development of Katsevich reconstruction formula, and the different forms of the Ramp filters can be designed to realize frequency modulation according to the actual clinical application.</p>

Population characteristics and individual variations of enhancement of pancreas and aorta: a contrastive analysis of 2 injection rates / 中南大学学报(医学版)

OBJECTIVE@#To contrastive analyze the population characteristics and individual variations of enhancement modes of normal pancreas and aorta at intravenous injection rates of 3 mL/s and 2 mL/s.@*METHODS@#Sixty-seven patients with normal pancreas were selected, and were divided randomly into 2 groups with different intravenous injection rates (3 mL/s for 35 patients in Group A and 2 mL/s for 32 patients in Group B). Single-level serial dynamic CT scan was performed at the level where the pancreas was best demonstrated. The enhancement values of pancreas and aorta for each time point of each patient were calculated, and the time-density curves of enhancement of pancreas and aorta of each patient were obtained. The peak enhancement and the time to reach the peak enhancement of pancreas and aorta of each individual patient were evaluated, and the 2 groups were compared. The individual variations of the enhancement modes of pancreas and aorta in each group were analyzed.@*RESULTS@#The peak enhancement of pancreas was (75.7+/-17.0) Hu at (43.9+/-6.6) s for Group A, and (66.5+/-16.0) Hu at (55.2+/-5.0) s for Group B; the peak enhancement of aorta was (226.2+/-35.2) Hu at (35.4+/-4.5) s for Group A, (182.8+/-32.8) Hu at (48.0+/-3.7) s for Group B. There were significant differences in both the peak enhancement and the time to reach the peak enhancement of pancreas and aorta between the 2 groups. The coefficients of variation of time to reach the peak enhancement for pancreas and aorta were 15.0% and 12.7% in Group A, and 9.2% and 7.7% in Group B, respectively. The temporal windows of the optimal enhancement of pancreas were (9.7+/-4.5)s and (13.7+/-3.6)s in Group A and B, respectively.@*CONCLUSION@#Better enhancement of pancreas and aorta is obtained at 3 mL/s than 2 mL/s, the time to reach the peak enhancement of pancreas and aorta is comparatively earlier at 3 mL/s than 2 mL/s, and the temporal windows of optimal enhancement of pancreas and aorta are comparatively shorter at 3 mL/s than 2 mL/s.