RESUMEN

BACKGROUND: Regular disease monitoring with low-dose high-resolution (LD-HR) computed tomography (CT) scans is necessary for the clinical management of people with cystic fibrosis (pwCF). The aim of this study was to compare the image quality and radiation dose of LD-HR protocols between photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) in pwCF. METHODS: This retrospective study included 23 pwCF undergoing LD-HR chest CT with PCCT who had previously undergone LD-HR chest CT with EID-CT. An intraindividual comparison of radiation dose and image quality was conducted. The study measured the dose-length product, volumetric CT dose index, effective dose and signal-to-noise ratio (SNR). Three blinded radiologists assessed the overall image quality, image sharpness, and image noise using a 5-point Likert scale ranging from 1 (deficient) to 5 (very good) for image quality and image sharpness and from 1 (very high) to 5 (very low) for image noise. RESULTS: PCCT used approximately 42% less radiation dose than EID-CT (median effective dose 0.54 versus 0.93 mSv, p < 0.001). PCCT was consistently rated higher than EID-CT for overall image quality and image sharpness. Additionally, image noise was lower with PCCT compared to EID-CT. The average SNR of the lung parenchyma was lower with PCCT compared to EID-CT (p < 0.001). CONCLUSION: In pwCF, LD-HR chest CT protocols using PCCT scans provided significantly better image quality and reduced radiation exposure compared to EID-CT. RELEVANCE STATEMENT: In pwCF, regular follow-up could be performed through photon-counting CT instead of EID-CT, with substantial advantages in terms of both lower radiation exposure and increased image quality. KEY POINTS: Photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) were compared in 23 people with cystic fibrosis (pwCF). Image quality was rated higher for PCCT than for EID-CT. PCCT used approximately 42% less radiation dose and offered superior image quality than EID-CT.

Asunto(s)

RESUMEN

The quality of Cone Beam Computed Tomography (CBCT) images is directly influenced by scanning and visualization protocols. Evaluate the subjective quality of the Cone Beam Computed Tomography (CBCT) image of different devices and protocols for diagnosing periodontal structures and correlate the findings with the contrast-to-noise ratio (CNR). One dry dentate mandible was scanned by six CBCT devices: Accuitomo 3D 170, CS 9000, CS 9300, Eagle 3D, i-CAT Classic, and Orthophos XG 3D. All CBCT devices were adjusted to provide a spatial resolution closest to 0.2 mm, and a FOV height limited to less than 100 mm. Cross-sectional images were evaluated randomly. The buccal bone coverage, the periodontal ligament space and the amount of image noise were assessed. The statistics were calculated based on a logistic regression model with the significance level set at 5%. Protocols with large FOVs demonstrated significantly lower image quality. No statistical differences were found regarding buccal bone coverage between the CBCT devices. The CNR showed the highest value for the Accuitomo 60mm x 60mm HiFi 180°, followed by the Accuitomo 60mm x 60mm HiFi 360°, and lower values for the i-Cat Classic and Orthophos XG 3D devices. Most protocols studied presented good image quality in evaluating the buccal bone coverage and periodontal ligament space. However, the exam with the lowest FOV of the Accuitomo 60mm x 60mm HiFi 180° device showed superiority concerning the others.(AU)

A qualidade das imagens de tomografia computadorizada de feixe cônico (CBCT) é diretamente influenciada pelos protocolos de digitalização e visualização. Avaliar a qualidade subjetiva da imagem da Tomografia Computadorizada de Feixe Cone (CBCT) de diferentes aparelhos e protocolos para o diagnóstico de estruturas periodontais e correlacionar os achados com a razão contraste-ruído (RCR). Uma mandíbula dentada seca foi digitalizada por seis dispositivos CBCT: Accuitomo 3D 170, CS 9000, CS 9300, Eagle 3D, i-CAT Classic e Orthophos XG 3D. Todos os dispositivos CBCT foram ajustados para fornecer uma resolução espacial próxima a 0,2 mm e uma altura de FOV limitada a menos de 100 mm. Imagens transversais foram avaliadas aleatoriamente. A cobertura óssea vestibular, o espaço do ligamento periodontal e a quantidade de ruído da imagem foram avaliados. As estatísticas foram calculadas com base em um modelo de regressão logística com nível de significância de 5%. Protocolos com grandes FOVs demonstraram qualidade de imagem significativamente inferior. Não foram encontradas diferenças estatísticas em relação à cobertura óssea vestibular entre os dispositivos CBCT. O CNR apresentou o maior valor para o Accuitomo 60mm x 60mm HiFi 180°, seguido pelo Accuitomo 60mm x 60mm HiFi 360°, e valores menores para os dispositivos i-Cat Classic e Orthophos XG 3D. A maioria dos protocolos estudados apresentou boa qualidade de imagem na avaliação da cobertura óssea vestibular e do espaço do ligamento periodontal. Entretanto, o exame com menor FOV do aparelho Accuitomo 60mm x 60mm HiFi 180° apresentou superioridade em relação aos demais. (AU)

RESUMEN

Dermatomyositis is an autoimmune disease involving the skin and muscles. At the onset of dermatomyositis, it is difficult to make an early diagnosis due to atypical clinical manifestations and lack of serological markers. Skin and muscle lesions are associated with disease activity and prognosis in patients with dermatomyositis or clinical amyopathic dermatomyositis. Computed tomography, magnetic resonance imaging, ultrasonography, dermoscopy and other imaging techniques may be used to assess skin and muscle involvements, which can not only improve the accuracy of early diagnosis of dermatomyositis, but also provide important reference for the assessment of disease activity and prognosis.

RESUMEN

ABSTRACT This study presents details about the applicability of the new image acquisition system, called the biplanar imaging system, with three-dimensional capabilities (EOS®) to the treatment of spinal deformities. This system allows radiographic acquisition of the entire body, with a great reduction in the dose of radiation absorbed by the patient and three-dimensional (3D) stereoradiographic image reconstruction of bone structures, including the spine. In the case of adolescent idiopathic scoliosis, the analysis of the spinal deformity with 3D reconstruction allows better understanding of the deformity and surgical planning. In the case of adult spinal deformity, full-body analysis allows an evaluation of the spinopelvic deformity, including loss of sagittal alignment, in addition to an evaluation of compensatory mechanisms recruited by the individual in an attempt to maintain the sagittal balance. Level of evidence III; Descriptive Review.

RESUMO O presente estudo apresenta detalhes sobre a aplicabilidade do novo sistema de aquisição de imagem, denominado sistema de imagem biplanar, com capacidade tridimensional (EOS®) no tratamento de deformidades da coluna vertebral. Tal sistema permite a aquisição radiográfica do corpo inteiro, com grande redução da dose de radiação absorvida pelo paciente e reconstrução estereoradiográfica em imagem tridimensional (3D) das estruturas ósseas, incluindo a coluna vertebral. No caso de escoliose idiopática do adolescente, a análise da deformidade da coluna vertebral com reconstrução 3D permite a melhor compreensão da deformidade e planejamento cirúrgico. No caso da deformidade da coluna vertebral do adulto, a análise do corpo inteiro permite a avaliação da deformidade espinopélvica, incluindo a perda do alinhamento sagital, além da avaliação adicional dos mecanismos compensatórios recrutados pelo indivíduo na tentativa de manter o equilíbrio sagital. Nível de evidência III; Revisão Descritiva.

RESUMEN El presente estudio presenta detalles sobre la aplicabilidad del nuevo sistema de adquisición de imagen denominado sistema de imagen biplanar, con capacidad tridimensional (EOS®) en el tratamiento de deformidades de la columna vertebral. Tal sistema permite la adquisición radiográfica del cuerpo entero, con gran reducción de la dosis de radiación absorbida por el paciente y reconstrucción estereorradiográfica en imagen tridimensional (3D) de las estructuras óseas, incluyendo la columna vertebral. En el caso de escoliosis idiopática del adolescente, el análisis de la deformidad de la columna vertebral con reconstrucción 3D permite la mejor comprensión de la deformidad y planificación quirúrgica. En el caso de la deformidad de la columna vertebral del adulto, el análisis del cuerpo entero permite la evaluación de la deformidad espinopélvica, incluyendo la pérdida de la alineación sagital, además de la evaluación adicional de los mecanismos compensatorios reclutados por el individuo en el intento de mantener el equilibrio sagital. Nivel de evidencia III; Revisión Descriptiva.

Asunto(s)

RESUMEN

OBJECTIVES: Evaluation of sparse sampling computed tomography (SpSCT) regarding subjective and objective image criteria for the detection of pulmonary embolism (PE) at different simulated dose levels. METHODS: Computed tomography pulmonary angiography (CTPA) scans of 20 clinical patients were used to obtain simulated low-dose scans with 100%-50%-25%-12.5%-6.3%-3.1% of the clinical dose, resulting in a total of six dose levels (DL). From these full sampling (FS) data, every second (2-SpSCT) or fourth (4-SpSCT) projection was used to obtain simulated sparse sampling scans. Each image set was evaluated by four blinded radiologists regarding subjective image criteria (artifacts, image quality) and diagnostic performance (confidence, sensitivity, specificity, accuracy, and area under the curve). Additionally, the contrast-to-noise ratio (CNR) was evaluated for objective image quality. RESULTS: Sensitivity was 100% with 2-SpSCT and 4-SpSCT at the 25% DL and the 12.5% DL for all localizations of PE (one subgroup 98.5%). With FS, the sensitivity decreased to 90% at the 12.5% DL. 2-SpSCT and 4-SpSCT showed higher values for sensitivity, specificity, accuracy, and the area under the curve at all DL compared with FS. Subjective image quality was significantly higher for 4-SpSCT compared with FS at each dose level (p < 0.01, paired t test). Only with 4-SpSCT, all examinations were rated as showing diagnostic image quality at the 12.5% DL. CONCLUSIONS: Via SpSCT, a dose reduction down to a 12.5% dose level (corresponding to a mean effective dose of 0.38 mSv in the current study) for CTPA is possible while maintaining high image quality and full diagnostic confidence. KEY POINTS: • With sparse sampling CT, radiation dose could be significantly reduced in clinical routine. • Sparse sampling CT is a novel hardware solution with which less projection images are acquired. • In the current study, a dose reduction of 87.5% (corresponding to a mean effective dose of 0.38 mSv) for CTPA could be achieved while maintaining excellent diagnostic performance.

Asunto(s)

RESUMEN

This review article presents the radiological options for management of malignant gastric outflow obstruction distal to the pylorus. We place these options in context with surgical and endoscopic alternatives and recommend their use, particularly in those institutions where endoscopic alternatives may not be readily available.

Asunto(s)

RESUMEN

BACKGROUND: Hemangiomas are one of the common primary benign tumors of the intraosseous and soft tissue compartments in humans. Vertebral hemangiomas being the most common of all are seen in daily radiological practice. Hemangioma of the rib is rarely seen. CASE REPORT: We reported on a case of a rib lesion which had a classic imaging pattern of hemangioma. We highlighted the use of pre-operative embolization of such a vascular rib lesion before surgically removing the lesion by thoracotomy to reduce the risk of bleeding. CONCLUSIONS: We also emphasized overt complications of overzealous needling of such a vascular lesion for histopathological diagnosis as in our case.

RESUMEN

Imaging modalities have developed in tandem with technical developments in recent years. It is common practice worldwide to establish a medical imaging quality control system in accordance with resources and need. In2003, the Korean governmentinstituted a medical imaging quality control system for high-priced and high-end medical imaging equipment. Magnetic resonance imaging (MRI), computed tomography (CT), and mammography were included in this program. General image quality has continuously improved, but some problems remain. The medical imaging quality control program will be extended to other equipment such as positron emission tomography-CT, simulation CT for radiation treatment, and extracorporeal shockwave lithotripsy. Education programs for equipment control personnel should be improved and the quality control system should be refined.

Asunto(s)

RESUMEN

OBJECTIVE: To investigate, by digital radiology, the bone regeneration process in rats submitted to femoral osteotomy and treated with low power laser therapy. METHODS: Forty-five Wistar rats were subjected to transverse osteotomy of the right femur and divided randomly into three experimental groups (n = 15): animals not treated with laser therapy G (C), animals that received laser therapy with λ: 660nm G (660nm) and animals that received laser therapy with λ: 830nm G (830nm). Animals were sacrificed after 7, 14 and 21 days. The bone calluses were evaluated by digital X-ray at 65 kVp, 7mA and 0.032 s exposures. RESULTS: The values obtained were submitted to variance analysis (ANOVA) followed by the Tukey-Kramer test. The significance level adopted was 5%. The groups G (C), G (660nm), and G (830nm) at the 7(th) day showed a significant bone development, with p <0.0116; the groups G (C), G (660nm), and G (830nm) at the 14(th) day showed values of p <0.0001; at the 21(st) day,a higher degree of bone repair were observed in group G (830nm), and G (660nm), with p <0.0169. CONCLUSION: Based on the radiographic findings, G (830nm) showed more complete bone regeneration, as shown in the gray shades of the images. Level of Evidence II, Individual Study With Experimental Design.

RESUMEN

OBJECTIVE: To investigate, by digital radiology, the bone regeneration process in rats submitted to femoral osteotomy and treated with low power laser therapy. METHODS: Forty-five Wistar rats were subjected to transverse osteotomy of the right femur and divided randomly into three experimental groups (n = 15): animals not treated with laser therapy G (C), animals that received laser therapy with λ: 660nm G (660nm) and animals that received laser therapy with λ: 830nm G (830nm). Animals were sacrificed after 7, 14 and 21 days. The bone calluses were evaluated by digital X-ray at 65 kVp, 7mA and 0.032 s exposures. RESULTS: The values obtained were submitted to variance analysis (ANOVA) followed by the Tukey-Kramer test. The significance level adopted was 5%. The groups G (C), G (660nm), and G (830nm) at the 7th day showed a significant bone development, with p <0.0116; the groups G (C), G (660nm), and G (830nm) at the 14th day showed values of p <0.0001; at the 21st day,a higher degree of bone repair were observed in group G (830nm), and G (660nm), with p <0.0169. CONCLUSION: Based on the radiographic findings, G (830nm) showed more complete bone regeneration, as shown in the gray shades of the images. Level of Evidence II, Individual Study With Experimental Design. .

RESUMEN

PURPOSE: Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. MATERIALS AND METHODS: Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. RESULTS: The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). CONCLUSIONS: Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment.

RESUMEN

OBJECTIVE: To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. MATERIALS AND METHODS: In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. RESULTS: The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. CONCLUSION: LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs.

Asunto(s)

RESUMEN

OBJECTIVE: To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. MATERIALS AND METHODS: In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. RESULTS: The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules > or = 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules > or = 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. CONCLUSION: LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs > or = 10 mm by both software programs.

Asunto(s)

RESUMEN

PURPOSE: Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. MATERIALS AND METHODS: Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. RESULTS: The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). CONCLUSIONS: Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment.

Asunto(s)

RESUMEN

PURPOSE: Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute. MATERIALS AND METHODS: We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging. RESULTS: The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm. CONCLUSIONS: Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.

RESUMEN

PURPOSE: Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute. MATERIALS AND METHODS: We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging. RESULTS: The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm. CONCLUSIONS: Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.

Asunto(s)

RESUMEN

PURPOSE: Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute. MATERIALS AND METHODS: We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging. RESULTS: The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm. CONCLUSIONS: Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.

Asunto(s)

RESUMEN

O objetivo deste estudo foi avaliar a eficácia da Irrigação Ultrassônica Passiva (IUP) na limpeza e eliminação Enterococcus faecalis de canais radiculares, em comparação à Irrigação Manual Convencional (IMC). O estudo foi dividido em dois capítulos. No capítulo I, foram utilizadas raízes de 75 dentes unirradiculados humanos extraídos. Após o preparo biomecânico, os espécimes foram divididos em cinco microplacas de cultura e esterilizados em óxido de etileno. Os canais radiculares foram contaminados com Enterococcus faecalis (ATCC 29212) e incubados a 37ºC durante 21 dias. As microplacas com os espécimes foram divididas em cinco grupos de acordo com o protocolo de irrigação utilizado (n=15): G1- IUP com solução salina; G2- IUP com NaOCl 1%; G3- IMC com solução salina; G4- IMC com NaOCl 1%; G5- controle (sem irrigação). Foram realizadas três coletas microbiológicas: inicial (após 21 dias de contaminação do canal), imediatamente após irrigação e final (após 7 dias dos tratamentos realizados). Após diluições decimais seriadas e semeadura, foi determinado o número de unidades formadoras de colônia por mililitro de solução (UFC/mL). No capítulo II, foram utilizadas raízes de dentes artificiais unirradiculados. Após o preparo dos canais radiculares, foram realizados quatro canais laterais nos terços apical e médio da raiz, nas superfícies vestibular e lingual. Posteriormente, os canais foram preenchidos com uma solução de contraste radiológico. Os espécimes foram divididos aleatoriamente em três grupos de acordo com o protocolo de irrigação (n=08): GI- IMC com agulha 30G, GII- IUP1 com fluxo intermitente, GIII- IUP2 com fluxo contínuo. Antes e após irrigação, os dentes foram radiografados no sentido proximal utilizando um sistema radiográfico digital. As áreas do canal radicular e canais laterais simulados antes (preenchido pelo contraste) e após irrigação (remanescente do contraste) foram mensuradas por meio do programa Image Tool 3.0. Os dados obtidos nos dois experimentos foram analisados por meio dos testes ANOVA e Tukey, com nível de significância de 5%. Na avaliação antimicrobiana, a coleta pós-irrigação não mostrou diferença estatisticamente significante entre G1 e G3 nem entre G2 e G4 (p>0,05), mas G2 e G4 mostraram uma contagem inferior de UFC/mL comparado aos demais grupos (p<0,05). Houve diferença estatisticamente significante entre a coleta inicial e pós-preparo e entre pós-preparo e a final (p<0,05) em todos os grupos, exceto no grupo controle. Na coleta final, todos os grupos apresentaram valores similares aos da coleta final. No teste avaliando a capacidade de limpeza, não houve diferença significante entre os grupos na remoção da solução de contraste do canal radicular principal mostrando porcentagem de limpeza similar (p>0,05). Nos canais laterais simulados, os resultados não mostraram diferenças significativas entre os grupos no terço médio (p>0,05). No terço apical, o grupo IUP1 mostrou-se superior, obtendo maior porcentagem de limpeza quando comparado ao grupo de IMC com diferença significante (p<0,05). Conforme as metodologias empregadas, pode-se concluir que a IUP e IMC associada à NaOCl a 1% contribui para diminuição da contaminação sem eliminar completamente de E. faecalis do sistema de canais radiculares. Quanto à remoção da solução de contraste dos canais radiculares e canais laterais simulados, a IUP com fluxo intermitente promoveu maior limpeza de canais laterais simulados no terço apical comparada à IMC

The aim of this study was to evaluate the cleaning efficacy and elimination of Enterococcus faecalis from the root canal provided by passive ultrasonic irrigation (PUI) compared with conventional needle irrigation (CNI). The study was divided into two chapters. In chapter I, seventy-five extracted human singlerooted teeth were used. After root canal instrumentation, specimens were randomly divided into cell culture microplates. The microplates containing the specimens were wrapped and sterilized by ethylene oxide. Root canals were inoculated with Enterococcus faecalis (ATCC 29212) and incubated at 37ºC for 21 days. The microplates containing the roots were randomly divided in five groups, according to the irrigation method: G1- PUI with saline solution, G2- PUI with 1% NaOCl, G3- CNI with saline solution, G4- CNI with 1% NaOCl, G5- control (no irrigation). Microbiological samples were collected at three time points: initial (21 days after inoculation), post-irrigation (immediately after irrigation), and final (7 days after irrigation). After serial decimal dilutions, the inocula were seeded and was determined the number of CFU/mL. In chapter II, single-rooted artificial teeth were used. After root canal instrumentation, four lateral canals were performed in the middle and apical thirds. After, the root canals were filled with a contrast solution. The roots were randomly divided into three groups, according to the irrigation technique (n=8): GI- IMC with 30-gauge needle, GII- IUP1 with intermittent flow and GIII- IUP2 with continuous flow. Before and after irrigation, the roots were radiographed using a digital radiographic system. The areas of the root canal and lateral canals simulated before (filled by contrast) and after irrigation (remainder of contrast) were measured using Image Tool 3.0 software. Data obtained from the two experiments were subjected to ANOVA and Tukey tests (5%). In antimicrobial test, the post-irrigation samples did not demonstrate statistically significant difference between G1 and G3 nor between G2 and G4 (p>0,05), but G2 and G4 showed a lower CFU/mL than the other groups (p<0,05). Statistically significant difference was observed between the initial and post-irrigation samples and between the post-irrigation and final samples (p<0,05) in all groups, except in the control. The final samples of all groups presented bacterial counts similar to the initial samples. In the ability cleaning test, there was no statistically significant difference between all groups in the removal of contrast solution of the root canal. In lateral canal simulated, the results showed no significant differences between all groups in the middle third. In the apical third, PUI1 (intermittent flow) was better, resulting greater percentage of cleaning when compared to group I (CNI) with significant differences. According with the methodologies employed, it can be concluded that PUI or CNI with 1% NaOCl contribute to the reduction of contamination without complete removal of E. faecalis from the RCS. Concerning the removal of the contrast solution of root canals and lateral canals simulated, PUI with intermittent flow was significantly effective in cleaning the lateral canals in the apical third in comparison with NCI

Asunto(s)

RESUMEN

It is difficult to take intraoral radiographs in some patients who are intolerable to place the film in their mouth. For these patients, Newman and Friedman recommended a new technique of extraoral film placement. Here we report various cases that diagnostic imaging was performed in patients using the extraoral periapical technique. This technique was used to obtain the radiographs for the patients with severe gag reflex, pediatric dental patients, and patients with restricted mouth opening. This technique can be recommended as an alternative to conventional intraoral periapical technique in cases where intraoral film placement is difficult to achieve.

RESUMEN

It is difficult to take intraoral radiographs in some patients who are intolerable to place the film in their mouth. For these patients, Newman and Friedman recommended a new technique of extraoral film placement. Here we report various cases that diagnostic imaging was performed in patients using the extraoral periapical technique. This technique was used to obtain the radiographs for the patients with severe gag reflex, pediatric dental patients, and patients with restricted mouth opening. This technique can be recommended as an alternative to conventional intraoral periapical technique in cases where intraoral film placement is difficult to achieve.

Asunto(s)