Atypical Pneumonia: Definition, Causes, and Imaging Features.

Pneumonia is among the most common causes of death worldwide. The epidemiologic and clinical heterogeneity of pneumonia results in challenges in diagnosis and treatment. There is inconsistency in the definition of the group of microorganisms that cause "atypical pneumonia." Nevertheless, the use of this term in the medical and radiologic literature is common. Among the causes of community-acquired pneumonia, atypical bacteria are responsible for approximately 15% of cases. Zoonotic and nonzoonotic bacteria, as well as viruses, have been considered among the causes of atypical pneumonia in a patient who is immunocompetent and have been associated with major community outbreaks of respiratory infection, with relevant implications in public health policies. Considering the difficulty of isolating atypical microorganisms and the significant overlap in clinical manifestations, a targeted empirical therapy is not possible. Imaging plays an important role in the diagnosis and management of atypical pneumonia, as in many cases its findings may first suggest the possibility of an atypical infection. Clarifying and unifying the definition of atypical pneumonia among the medical community, including radiologists, are of extreme importance. The prompt diagnosis and prevention of community spread of some atypical microorganisms can have a relevant impact on local, regional, and global health policies. ©RSNA, 2021.

Updated Fleischner Society Guidelines for Managing Incidental Pulmonary Nodules: Common Questions and Challenging Scenarios.

The new guidelines for managing incidental pulmonary nodules published by the Fleischner Society in 2017 reflect an improved understanding of the risk factors and biologic features of lung cancer. Specific topics emphasized in the updated guidelines include a new threshold size for follow-up, the importance of the morphologic features of nodules, accurate nodule measurements, recognition of subsolid components, understanding interval growth or change in nodule morphology, and knowledge of patient risk factors. The updated guidelines enable greater personal flexibility in the decision-making process and encourage individualized management of pulmonary nodules. These factors may introduce new challenges for radiologists, who previously used solely nodule size to make management recommendations. The authors describe eight scenarios that illustrate the challenges potentially encountered when applying the new guidelines to pulmonary nodule management. ©RSNA, 2018.

Assessment of single-bolus contrast administration technique using hybrid dual-source ECG-gated thoracic and dual-source non-ECG-gated high-pitch abdominopelvic CT acquisitions for procedural planning before transcatheter aortic valve replacement.

PURPOSE: This study aimed to assess vascular contrast opacification and homogeneity using single-bolus contrast administration with hybrid thoracic and abdominopelvic computed tomographic angiography in patients with severe aortic valve stenosis. MATERIALS AND METHODS: Combination electrocardiogram-gated thoracic and dual-source, high-pitch abdominopelvic computed tomographic angiography examinations of 50 patients with severe aortic stenosis between December 2013 and March 2014 were reviewed. Contrast administration was individualized to patient-specific physiology. Image analysis of vascular opacification was obtained and interdependencies of vascular contrast and homogeneity of contrast distribution were assessed. RESULTS: The mean volume of contrast administered was 106 ± 11.7 mL. Mean attenuation was 371 ± 90.7 Hounsfield units (HU) in the thoracic aorta and 388 ± 95.9 HU in the abdominal aorta. Homogeneous opacification was obtained throughout with coefficient of variation of 11%. CONCLUSIONS: Procedural planning for transcatheter aortic valve replacement can be achieved using a single-injection bolus contrast protocol in combination with a 2-part multidetector computed tomographic image acquisition technique with optimal opacification of major arterial structures.

Hyperpolarized Xenon-129: A New Tool to Assess Pulmonary Physiology in Patients with Pulmonary Fibrosis.

PURPOSE: The existing tools to quantify lung function in interstitial lung diseases have significant limitations. Lung MRI imaging using inhaled hyperpolarized xenon-129 gas (129Xe) as a contrast agent is a new technology for measuring regional lung physiology. We sought to assess the utility of the 129Xe MRI in detecting impaired lung physiology in usual interstitial pneumonia (UIP). MATERIALS AND METHODS: After institutional review board approval and informed consent and in compliance with HIPAA regulations, we performed chest CT, pulmonary function tests (PFTs), and 129Xe MRI in 10 UIP subjects and 10 healthy controls. RESULTS: The 129Xe MRI detected highly heterogeneous abnormalities within individual UIP subjects as compared to controls. Subjects with UIP had markedly impaired ventilation (ventilation defect fraction: UIP: 30 ± 9%; healthy: 21 ± 9%; p = 0.026), a greater amount of 129Xe dissolved in the lung interstitium (tissue-to-gas ratio: UIP: 1.45 ± 0.35%; healthy: 1.10 ± 0.17%; p = 0.014), and impaired 129Xe diffusion into the blood (RBC-to-tissue ratio: UIP: 0.20 ± 0.06; healthy: 0.28 ± 0.05; p = 0.004). Most MRI variables had no correlation with the CT and PFT measurements. The elevated level of 129Xe dissolved in the lung interstitium, in particular, was detectable even in subjects with normal or mildly impaired PFTs, suggesting that this measurement may represent a new method for detecting early fibrosis. CONCLUSION: The hyperpolarized 129Xe MRI was highly sensitive to regional functional changes in subjects with UIP and may represent a new tool for understanding the pathophysiology, monitoring the progression, and assessing the effectiveness of treatment in UIP.

TeleResidents: Exploring the use of Resident Home Workstations During the COVID Pandemic.

RATIONALE AND OBJECTIVES: Since the beginning of the COVID-19 pandemic, numerous strategies have been proposed to allow for continued resident education while following social distancing guidelines. Diagnostic radiology is largely electronic work, allowing for relatively easy transition to telehealth. Our institution deployed home workstations to interested upper level radiology residents and fellows in order to maintain high volume workload and education, while complying with CDC social distancing and quarantine guidelines. MATERIALS AND METHODS: We deployed 28 home workstations with integrated PACS, electronic health record, and reporting system, supporting workflow that matched our on-site processes and allowing residents to work from home while on diagnostic rotations. Two months into the pilot, surveys were sent to trainees and faculty to assess satisfaction related to education, productivity, and wellness. A retrospective study count was performed for a sample of residents in order to assess productivity. RESULTS: Residents perceived their remote productivity as unchanged or better than at the hospital, while faculty were more likely to perceive it as decreased, however, objective results showed no difference. Education was largely considered worse or unchanged with very few regarding it as improved. Those utilizing shared-screen signout platforms rated education better than those utilizing voice/telephone communications only. Trainees expressed improvement in wellness and quality of life. CONCLUSION: Home workstations for trainees represent a feasible solution for implementing social distancing or even quarantine while maintaining operational productivity. There is the added benefit of scheduling flexibility, option to overcome space constraints, and improved quality of life.

Preprocedural Imaging Evaluation of Pulmonary Valve Replacement After Repair of Tetralogy of Fallot: What the Radiologist Needs to Know.

Tetrallogy of Fallot (TOF) is the most frequent form of cyanotic congenital heart disease. Despite advances in surgical and medical treatment, mortality remains high. Residual dysfunction of the pulmonary valve (PV) after correction of right ventricular outflow tract obstruction is an important cause of morbidity, leading to irreversible right ventricular dysfunction, arrhythmias, heart failure and occasionally, death. The strategies for PVR have evolved over the last decades, and the timing of the intervention remains the foundation of the decision-making process. Symptoms of heart failure are unreliable indicators for optimal timing of repair. Imaging plays an essential role in the assessment of PV integrity and dysfunction. The identification of the best timing for PVR requires a multimodality approach. Transthoracic echocardiography is the most commonly used imaging modality for the initial assessment and follow-up of TOF patients, although its utility has technical limitations, especially in adults. Cardiac computed tomography and magnetic resonance imaging are now routinely used for preoperative and postoperative evaluation of these patients, and provide highly valuable information about the anatomy and pathophysiology. Imaging evidence of disease progression is now part of the major guidelines to define the best timing for reintervention. The purpose of this article is to review the pathophysiology after TOF repair, identify the main imaging anatomic and physiologic features, describe the indications for PVR and recognize the role of imaging in the assessment of these patients to define the appropriate timing of PVR.

Interdisciplinary simulation scenario in nursing education: Humanized childbirth and birth.

OBJECTIVE: to develop and validate with a panel of experts a scenario of maternal-child clinical simulation, related to humanized childbirth and birth. METHOD: methodological study based on the Jeffries framework and standardized guides of the International Nursing Association for Clinical Simulation in Learning, which used analysis with descriptive statistics for general aspects of adherence to the aforementioned guide and inferential statistics for validating the checklist of actions through the Intraclass Correlation Coefficient (ICC). RESULTS: the scenario contains learning objectives, necessary resources, prebriefing and debriefing of guidelines, description of the simulated situation, participants and roles, and checklist of expected actions. The validation obtained an agreement level above 80% in all aspects evaluated by 31 experts, highlighting realism of the environment and setting, vital sign parameters, alignment with scientific literature and encouragement of critical thinking and problem solving. In addition, the checklist of actions was validated with 0.899 agreement among experts, statistically analyzed by the ICC and Cronbach's alpha 0.908 (95% confidence interval). CONCLUSION: the simulated scenario on humanized childbirth and birth can strengthen the articulation between women's and children's health disciplines, and was validated by experts.

MR Imaging of Primary Chest Wall Neoplasms.

Primary chest wall neoplasms are uncommon and comprise a heterogeneous group of lesions that may be challenging to classify and diagnose. These tumors may be primary or secondary, malignant or benign, and arise from cartilaginous/osseous structures or soft tissues. The role of magnetic resonance (MR) imaging in the evaluation of chest wall tumors continues to expand given its superior soft tissue contrast relative to computed tomography. MR imaging can facilitate differentiation of neoplasms from normal chest wall structures and other disease processes due to infection and inflammation, and can fully characterize abnormalities by demonstrating the various internal components of complex lesions. It is important that radiologists be able to identify key features of primary chest wall neoplasms on MR imaging to provide focused differential diagnoses and guide patient management.

MR Imaging of Cardiac Masses.

Cardiac masses present a diagnostic challenge given their relative rarity and the overall difficulty imaging the heart. With the increasing frequency and quality of imaging in general, however, the incidental discovery of cardiac masses is increasing. Cardiac masses seldom produce symptoms, and they are more commonly found during imaging for noncardiac indications. While echocardiography is useful in the initial evaluation of a suspected mass, cardiac magnetic resonance (MR) imaging is the best imaging modality to characterize cardiac tumors due to its superior tissue characterization and its higher contrast resolution. Due to the risk of embolization and arrhythmia, most benign cardiac tumors are removed, and imaging plays an important role in treatment planning. While primary resection remains the mainstay of treatment, new treatment strategies may prolong survival and slow the growth of metastases. A fundamental knowledge of common cardiac masses is vital to all radiologists, and here, we discuss the most pertinent imaging approach to cardiac masses emphasizing MR imaging.

Evaluation of body image, quality of life, tactile sensitivity and pain in women with breast cancer submitted to surgical intervention.

OBJECTIVE: Breast cancer is one of the most common types of tumor in the world and the most common among women. There are several treatments for breast cancer; however, the condition often can be accompanied by severe complications in a woman's life. To evaluate and compare body image perception, quality of life, tenderness, and pain in women with breast cancer during preoperative and postoperative periods of 30, 60 and 90 days. MATERIALS AND METHODS: We conducted a prospective longitudinal study. The patients answered the questionnaire "How I relate to my own body", EORTC QLQ-C30 and EORTC QLQ-BR23. We assessed upper limb and breast sensitivity with an esthesiometer. Patients were questioned about the presence and level of pain on a scale of 0 to 10. RESULTS: For body image, it was possible to observe a significant difference between pre and postoperative at 30 days. There were changes in some areas of the EORTC QLQ C30 and EORTC QLQ BR23 questionnaires, such as arm and breast symptoms, social function, constipation, sexual function and satisfaction, among others. For evaluation of breast and axilla sensitivity and assessment of pain, all postoperative periods showed significant differences when compared to the preoperative period. The sensitivity of the inner region of the arm presented no significant change. CONCLUSION: The difference found in the study shows that evaluations on all scales should be done in several periods, using a proper treatment for the changes and individuality of each patient.

Pneumothorax in the Supine Patient: Subtle Radiographic Signs.

Routine posteroanterior chest radiographs and computed tomography scans are more sensitive for detecting pneumothoraces than anteroposterior chest radiographs. However, supine chest radiographs are commonly performed as part of the initial and routine assessment of trauma and critically ill patients. Rates of occult pneumothorax can be as high as 50% and have a significant impact in the mortality of these patients; thus, a prompt diagnosis of this entity is important. This pictorial essay will illustrate the pleural anatomy, explain the distribution of air within the pleural space in the supine position, and review the radiologic findings that characterize this entity.

What's New in 10 Years? A Revised Cardiothoracic Curriculum for Diagnostic Radiology Residency with Goals and Objectives Related to General Competencies.

This is a cardiothoracic curriculum document for radiology residents meant to serve not only as a study guide for radiology residents but also as a teaching and curriculum reference for radiology educators and radiology residency program directors. This document represents a revision of a cardiothoracic radiology resident curriculum that was published 10 years ago in Academic Radiology. The sections that have been significantly revised, expanded, or added are (1) lung cancer screening, (2) lung cancer genomic profiling, (3) lung adenocarcinoma revised nomenclature, (4) lung biopsy technique, (5) nonvascular thoracic magnetic resonance, (6) updates to the idiopathic interstitial pneumonias, (7) cardiac computed tomography updates, (8) cardiac magnetic resonance updates, and (9) new and emerging techniques in cardiothoracic imaging. This curriculum was written and endorsed by the Education Committee of the Society of Thoracic Radiology. This curriculum operates in conjunction with the Accreditation Council for Graduate Medical Education (ACGME) milestones project that serves as a framework for semiannual evaluation of resident physicians as they progress through their training in an ACGME-accredited residency or fellowship programs. This cardiothoracic curriculum document is meant to serve not only as a more detailed guide for radiology trainees, educators, and program directors but also complementary to and guided by the ACGME milestones.

Physiological and lifestyle factors contributing to risk and severity of peri-orbital dark circles in the Brazilian population.

BACKGROUND: Peri-orbital dark circles are a cosmetic concern worldwide, and have been attributed to hyperpigmentation from allergy or atopic dermatitis, blood stasis, structural shadowing effects, and a thin epidermis/dermis under the eye. It is of interest to better understand lifestyle and demographic risk factors and the relative impact of melanin, blood and epidermal/dermal factors on the severity of Peri-orbital dark circles. OBJECTIVE: To compare by non-invasive imaging the impact of biological factors to a visual grading scale for Peri-orbital dark circles, and test the correlation of various demographic factors with Peri-orbital dark circles. METHODS: Subjects completed a lifestyle and health survey, and Peri-orbital dark circles severity was evaluated using standardized photographs. Hyperspectral image analysis was used to assess the contributions of melanin, blood volume, degree of blood oxygen saturation, and dermal scattering. RESULTS: Family history was the most significant risk factor for Peri-orbital dark circles. The average age of onset was 24 years, and earlier onset correlated with higher severity scores. Asthma was significantly associated with Peri-orbital dark circles scores, but self-reported allergy was not. In this study, sleep was not correlated with Peri-orbital dark circles scores. Hyperspectral imaging indicated that melanin was the dominant correlate for Peri-orbital dark circles severity, while oxygen saturation was secondary. The difference between under-eye and cheek measurements for ΔL*and ΔE* were the most significant instrumental parameters correlated with visual assessment of Peri-orbital dark circles severity. CONCLUSION: Although typically associated with lack of sleep, risk of Peri-orbital dark circles is primarily hereditary. The main factors contributing to the appearance of Peri-orbital dark circles are melanin and (deoxygenated) blood.

Interdisciplinary simulation scenario in nursing education: Humanized childbirth and birth / Cenário de simulação interdisciplinar na educação em enfermagem: parto e nascimento humanizados / Escenario de simulación interdisciplinaria en educación en enfermería: parto y nacimiento humanizados

Objective: to develop and validate with a panel of experts a scenario of maternal-child clinical simulation, related to humanized childbirth and birth. Method: methodological study based on the Jeffries framework and standardized guides of the International Nursing Association for Clinical Simulation in Learning, which used analysis with descriptive statistics for general aspects of adherence to the aforementioned guide and inferential statistics for validating the checklist of actions through the Intraclass Correlation Coefficient (ICC). Results: the scenario contains learning objectives, necessary resources, prebriefing and debriefing of guidelines, description of the simulated situation, participants and roles, and checklist of expected actions. The validation obtained an agreement level above 80% in all aspects evaluated by 31 experts, highlighting realism of the environment and setting, vital sign parameters, alignment with scientific literature and encouragement of critical thinking and problem solving. In addition, the checklist of actions was validated with 0.899 agreement among experts, statistically analyzed by the ICC and Cronbach's alpha 0.908 (95% confidence interval). Conclusion: the simulated scenario on humanized childbirth and birth can strengthen the articulation between women's and children's health disciplines, and was validated by experts.

Objetivo: desenvolver e validar junto a um painel de experts um cenário de simulação clínica materno-infantil, relacionado ao parto e nascimento humanizados. Método: estudo metodológico baseado no referencial de Jeffries e guias padronizados da International Nursing Association for Clinical Simulation in Learning, que utilizou análise com estatística descritiva para aspectos gerais de adesão aos guias supracitados e inferencial para validação do checklist de ações por meio de Intraclass Correlation Coeficient (ICC). Resultados: o cenário contém objetivos de aprendizagem, recursos necessários, orientações de prebriefing e debriefing, descrição da situação simulada, participantes e papéis, e checklist de ações esperadas. A validação obteve nível de concordância superior a 80% em todos os aspectos avaliados por 31 experts, destacando realismo do ambiente e cenário, parâmetros de sinais vitais, alinhamento com a literatura científica e estímulo ao pensamento crítico e resolução de problemas. Ainda, foi validado o checklist de ações com concordância de 0,899 entre experts, analisado estatisticamente pelo teste de ICC e alpha de Cronbach 0,908 (intervalo de confiança 95%). Conclusão: o cenário simulado sobre parto e nascimento humanizados pode fortalecer a articulação entre as disciplinas de saúde da mulher e da criança, e foi validado por experts.

Objetivo: desarrollar y validar con un panel de expertos un escenario de simulación clínica materno-infantil, relacionado con el parto y el nacimiento humanizados. Método: estudio metodológico basado en el marco de Jeffries y guías estandarizadas de la International Nursing Association for Clinical Simulation in Learning, que utilizó análisis con estadísticas descriptivas para los aspectos generales de la adhesión a las guías mencionadas e inferenciales para validar la checklist de acciones a través del Intraclass Correlation Coeficient (ICC). Resultados: el escenario contiene objetivos de aprendizaje, recursos necesarios, orientaciones de prebriefing y debriefing, directrices, descripción de la situación simulada, participantes y roles, y checklist de las acciones esperadas. La validación obtuvo un nivel de acuerdo superior al 80% en todos los aspectos evaluados por 31 expertos, destacando el realismo del entorno y el entorno, los parámetros de los signos vitales, la alineación con la literatura científica y el estímulo del pensamiento crítico y la resolución de problemas. Además, el checklist de acciones fue validado con un acuerdo de 0,899 entre expertos, analizada estadísticamente por la prueba ICC y el alfa de Cronbach 0,908 (intervalo de confianza del 95%). Conclusión: el escenario simulado sobre el nacimiento humanizado y el parto puede fortalecer la articulación entre las disciplinas de salud de mujeres y niños, y fue validado por expertos.

Práctica del psicoanalista en la institución: ¿análisis o sugestión? / Practice of the psychoanalyst at the institutional level: analysis or suggestion?

Resumen En el marco de la investigación titulada: Práctica de los psicoanalistas en las instituciones de salud mental en el contexto latinoamericano. Un estado del arte (2000-2013), se mantuvo como eje la pregunta por la presencia del psicoanalista en contextos diferentes al dispositivo analítico clásico, el cual se enmarca en el ámbito de lo privado. Una referencia obligada en esta vía es aquella frase freudiana que evoca la aleación entre el oro puro del análisis y el cobre de la sugestión directa. El presente texto es una elaboración al respecto y sus consecuencias para una praxis psicoanalítica en el ámbito institucional. Para ello se revisaron distintas fuentes en la obra de Freud y en la enseñanza de Lacan, que, junto con otros autores, intentan dar cuenta de las dificultades y posibilidades para que ello sea viable. Se evidencia que los detractores de esta opción se concentran en lo imaginario del dispositivo, mientras que otros más orientados por la estructura del mismo y la función deseo del analista señalan la pertinencia de esta praxis por fuera del dispositivo clásico.

Abstract Within the framework of the research entitled: "Practice of psychoanalysts in mental health institutions in the Latin American context. A state of art (2000-2013) ", the question of the presence of psychoanalysts in contexts different from the classic analytical device, which is framed in the private sphere, was kept as the axis. An obligatory reference in this way is the Freudian phrase that evokes the alloy between the pure gold of the analysis and the copper of the direct suggestion. The present text is an elaboration on this and its consequences for a psychoanalytic praxis at the institutional level. For this, different sources were reviewed in the work of Freud and the lessons of Lacan, which together with other authors attempt to account for the difficulties and possibilities for this to be viable. It is evident that the detractors of this option concentrate on the imaginary of the device, while others are more oriented by the structure of the device and the desired function that the analyst points out.

Evaluation of body image, quality of life, tactile sensitivity and pain in women with breast cancer submitted to surgical intervention

SUMMARY Breast cancer is one of the most common types of tumor in the world and the most common among women. There are several treatments for breast cancer; however, the condition often can be accompanied by severe complications in a woman's life. OBJECTIVE: o evaluate and compare body image perception, quality of life, tenderness, and pain in women with breast cancer during preoperative and postoperative periods of 30, 60 and 90 days. MATERIALS AND METHODS: We conducted a prospective longitudinal study. The patients answered the questionnaire "How I relate to my own body", EORTC QLQ-C30 and EORTC QLQ-BR23. We assessed upper limb and breast sensitivity with an esthesiometer. Patients were questioned about the presence and level of pain on a scale of 0 to 10. RESULTS: For body image, it was possible to observe a significant difference between pre and postoperative at 30 days. There were changes in some areas of the EORTC QLQ C30 and EORTC QLQ BR23 questionnaires, such as arm and breast symptoms, social function, constipation, sexual function and satisfaction, among others. For evaluation of breast and axilla sensitivity and assessment of pain, all postoperative periods showed significant differences when compared to the preoperative period. The sensitivity of the inner region of the arm presented no significant change. CONCLUSION: The difference found in the study shows that evaluations on all scales should be done in several periods, using a proper treatment for the changes and individuality of each patient.

RESUMO O câncer de mama é um dos tipos mais comuns de tumores no mundo e o tipo mais comum entre as mulheres. Existem tratamentos severos para o câncer de mama, no entanto, em muitos casos, podem ser acompanhados por complicações sérias para a vida da mulher. OBJETIVO: Avaliar e comparar a percepção da imagem corporal, a qualidade de vida, a sensibilidade e a dor em mulheres com câncer de mama nos períodos pré-operatório e pós-operatório de 30, 60 e 90 dias. MÉTODOS: Foi realizado um estudo longitudinal prospectivo. Os pacientes responderam ao questionário "Como me relaciono com meu próprio corpo", o EORTC QLQ-C30 e o EORTC QLQ-BR23. Fizemos uma avaliação da sensibilidade do membro superior e da mama com um estesiômetro. Os pacientes foram questionados sobre a presença de dor e seu nível em uma escala de 0 a 10. RESULTADOS: Para a imagem corporal, foi possível observar uma diferença significativa entre o pré e pós-operatório de 30 dias. Mostrou mudanças em algumas áreas dos questionários EORTC QLQ C30 e EORTC QLQ BR23, como sintomas de braço e mama, função social, constipação e função sexual e satisfação, entre outros. Para avaliação da sensibilidade mamária e axilar e avaliação da dor, todos os períodos de pós-operatório apresentaram diferenças significativas quando comparados ao período pré-operatório. A sensibilidade da região interna do braço não apresentou mudanças significativas. CONCLUSÃO: A diferença encontrada no estudo mostra que as avaliações em todas as escalas devem ser feitas em vários períodos, utilizando um tratamento adequado que enfrente as mudanças e a individualidade de cada paciente.

Evaluation of the tip of standardized D0 gutta percha cones of four Rotary systems, by means of an endodontic ruler / Avaliação da adaptação de cones estandardizados de guta-percha de quatro sistemas mecanizados por meio de uma régua endodôntica calibradora

ABSTRACT Objective : This study aimed to evaluate the D0 diameter of standardized gutta-percha cones for four mechanized systems: ProTaper Universal®, Mtwo®, Wave One® and Reciproc®. Methods: An endodontic calibrator ruler was used to measure the D0 diameter of 60 main cones of the above systems. Measurements were made according 3 scores as follows: gutta-percha cone fits exactly into the same hole as the endodontic ruler gauge (score 1), cone falls short of the ruler gauge whole size (score 2); or exceeding the ruler gauge hole size (score 3). The diameters D0 obtained were compared with the values reported by manufacturers. All data were analyzed by means of T Test, at 1% level of significance. Results: The average value measured was significantly higher than the measures established by manufacturers (p <0.001). Conclusion : The gutta-percha cones of ProTaper Universal® systems Mtwo®, Wave One® and Reciproc® were not standardized, except for R40 cone of the Reciproc® system (Reciproc®). The trend was for variation in the D0 Diameter towards increasing measurement values.

RESUMO Objetivo: Avaliar o diâmetro D0 de cones estandardizados de guta-percha de quatro sistemas mecanizados: ProTaper Universal®, Mtwo®, Wave One® e Reciproc® . Métodos: Por meio de uma régua endodôntica calibradora, foi aferido o diâmetro D0 de sessenta cones principais dos sistemas supracitados. A aferição foi realizada de acordo com os três escores a seguir: o cone de guta-percha se adapta exatamente no mesmo calibre de orifício da régua endodôntica (escore 1), o cone fica aquém ao calibre de orifício da régua (escore 2) ou além do respectivo calibre do orifício da régua (escore 3). Os diâmetros em D0 obtidos foram comparados aos valores divulgados pelos fabricantes. Todos os dados foram tratados por meio do Teste T, ao nível de significância de 1%. Resultados: As médias aferidas foram significativamente maiores do que as medidas estabelecidas pelos fabricantes (p<0,001). Somente os cones R40 do sistema Reciproc® estiveram no padrão. Conclusão: Os cones de guta-percha dos sistemas ProTaper Universal®, Mtwo®, Wave One® e Reciproc® não apresentam padronização, à exceção do cone R40 ( Reciproc® ). Houve uma tendência de variação do diâmetro D0 para uma maior medida.