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OBJECTIVE: to perform an external validation of two clinical decision instruments (DIs) - Chest CT-All and Chest CT-Major - in a cohort of patients with blunt chest trauma undergoing chest CT scanning at a trauma referral center, and determine if these DIs are safe options for selective ordering of chest CT scans in patients with blunt chest trauma admitted to emergency units. METHODS: cross-sectional study of patients with blunt chest trauma undergoing chest CT scanning over a period of 11 months. Chest CT reports were cross-checked with the patients' electronic medical record data. The sensitivity and specificity of both instruments were calculated. RESULTS: the study included 764 patients. The Chest CT-All DI showed 100% sensitivity for all injuries and specificity values of 33.6% for injuries of major clinical significance and 40.4% for any lesion. The Chest CT-Major DI had sensitivity of 100% for injuries of major clinical significance, which decreased to 98.6% for any lesions, and specificity values of 37.4% for injuries of major clinical significance and 44.6% for all lesions. CONCLUSION: both clinical DIs validated in this study showed adequate sensitivity to detect chest injuries on CT and can be safely used to forego chest CT evaluation in patients without any of the criteria that define each DI. Had the Chest CT-All and Chest CT-Major DIs been applied in this cohort, the number of CT scans performed would have decreased by 23.1% and 24.6%, respectively, resulting in cost reduction and avoiding unnecessary radiation exposure.

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ABSTRACT Objective: to perform an external validation of two clinical decision instruments (DIs) - Chest CT-All and Chest CT-Major - in a cohort of patients with blunt chest trauma undergoing chest CT scanning at a trauma referral center, and determine if these DIs are safe options for selective ordering of chest CT scans in patients with blunt chest trauma admitted to emergency units. Methods: cross-sectional study of patients with blunt chest trauma undergoing chest CT scanning over a period of 11 months. Chest CT reports were cross-checked with the patients' electronic medical record data. The sensitivity and specificity of both instruments were calculated. Results: the study included 764 patients. The Chest CT-All DI showed 100% sensitivity for all injuries and specificity values of 33.6% for injuries of major clinical significance and 40.4% for any lesion. The Chest CT-Major DI had sensitivity of 100% for injuries of major clinical significance, which decreased to 98.6% for any lesions, and specificity values of 37.4% for injuries of major clinical significance and 44.6% for all lesions. Conclusion: both clinical DIs validated in this study showed adequate sensitivity to detect chest injuries on CT and can be safely used to forego chest CT evaluation in patients without any of the criteria that define each DI. Had the Chest CT-All and Chest CT-Major DIs been applied in this cohort, the number of CT scans performed would have decreased by 23.1% and 24.6%, respectively, resulting in cost reduction and avoiding unnecessary radiation exposure.

RESUMO Objetivo: realizar validação externa de dois instrumentos de decisão clínica (IDCs) - TC de tórax-All e TC de tórax-Major - em uma coorte de pacientes com trauma torácico fechado submetidos a tomografia computadorizada de tórax em centro de referência para trauma, e determinar se esses IDCs são opções seguras para solicitação seletiva de tomografias computadorizadas de tórax em pacientes com trauma torácico fechado admitidos em unidades de emergência. Métodos: estudo retrospectivo transversal de pacientes com trauma torácico fechado submetidos a tomografia computadorizada de tórax, por período de 11 meses. Os laudos da TC de tórax foram cruzados com os dados do prontuário eletrônico dos pacientes. A sensibilidade e especificidade de ambos os instrumentos foram calculadas. Resultados: o estudo incluiu 764 pacientes. O IDC TC de tórax-All apresentou sensibilidade de 100% para todas as lesões e especificidades de 33,6% para lesões de maior significado clínico e 40,4% para qualquer lesão. O IDC TC de tórax Major teve sensibilidade de 100% para lesões de maior significado clínico, que diminuiu para 98,6% para quaisquer lesões, e especificidades de 37,4% para lesões de maior significado clínico e 44,6% para todas as lesões. Conclusão: ambos os instrumentos de decisão clínica validados neste estudo mostraram sensibilidade adequada para detectar lesões torácicas na TC e podem ser usados com segurança para dispensar a avaliação da TC de tórax em pacientes sem nenhum dos critérios que definem o IDC. Se os IDCs TC de tórax-All e TC de tórax Major de tórax tivessem sido aplicados nesta coorte, o número de tomografias realizadas teria diminuído em 23,1% e 24,6%, respectivamente, resultando em redução de custos e evitando exposição desnecessária à radiação.

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La guía de referencia rápida tiene como objetivo proporcionar al usuario las recomendaciones clave de la guía. Abordaje diagnóstico y terapéutico de la neumonía viral grave, seleccionadas con base a su impacto en salud por el grupo desarrollador, las cuales pueden variar en función de la intervención de que se trate, así como del contexto regional o local en el ámbito de su aplicación.

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The aim of this study was to compare the performance of three digital X-ray systems [one flat-panel (DR) and two computed radiography (CR)] for chest radiography in terms of the entrance surface air kerma (ESAK) delivered to a polymethyl methacrylate phantom of 20 cm (equivalent to an adult patient) and image quality through of numerical evaluations using a test object (TO). The tube charge applied was ranged from 0.6 to 32 mAs, to a fixed tension of 125 kVp. The DR system presented the highest mean values of ESAK (615.9 µGy) along with the highest signal-to-noise ratio values, whereas CR systems showed a better high-contrast spatial resolution. Differences were statistically significant in both cases regarding the tube charge used. Thus, this parameter should be mainly considered to optimise the radiological protection through exposure settings selected. This survey represents the first effort to achieve optimisation in digital radiology for Chile.

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OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy achieved with and without the calibration method established by the DICOM standard in both medical-grade gray-scale displays and consumer-grade color displays. MATERIALS AND METHODS: This study involved 76 cases, six radiologists, three displays, and two display calibrations for a total of 2736 observations in a multireader-multicase factorial design. The evaluated conditions were interstitial opacities, pneumothorax, and nodules. CT was adopted as the reference standard. One medical-grade gray-scale display and two consumer-grade color displays were evaluated. Analyses of ROC curves, diagnostic accuracy (measured as AUC), accuracy of condition classification, and false-positive and false-negative rate comparisons were performed. The degree of agreement between readers was also evaluated. RESULTS: No significant differences in image quality perception by the readers in the presence or absence of calibration were observed. Similar forms of the ROC curves were observed. No significant differences were detected in the observed variables (diagnostic accuracy, accuracy of condition classification, false-positive rates, false-negative rates, and image-quality perception). Strong agreement between readers was also determined for each display with and without calibration. CONCLUSION: For the chest conditions and selected observers included in this study, no significant differences were observed between the three evaluated displays with respect to accuracy performance with and without calibration.

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INTRODUCTION: In teleradiology services and in hospitals, the extensive use of visualization displays requires affordable devices. The purpose of this study was to compare three differently priced displays (a medical-grade grayscale display and two consumer-grade color displays) for image visualization of digitized chest X-rays. MATERIALS AND METHODS: The evaluated conditions were interstitial opacities, pneumothorax, and nodules using computed tomography as the gold standard. The comparison was accomplished in terms of receiver operating characteristic (ROC) curves, the diagnostic power measured as the area under ROC curves, accuracy in conditions classification, and main factors affecting accuracy, in a factorial study with 76 cases and six radiologists. RESULTS: The ROC curves for all of the displays and pathologies had similar shapes and no differences in diagnostic power. The proportion of cases correctly classified for each display was greater than 71.9%. The correctness proportions of the three displays were different (p<0.05) only for interstitial opacities. The evaluation of the main factors affecting these proportions revealed that the display factor was not significant for either nodule size or pneumothorax size (p>0.05). CONCLUSIONS: Although the image quality variables showed differences in the radiologists' perceptions of the image quality of the three displays, significant differences in the accuracy did not occur. The main effect on the variability of the proportions of correctly classified cases did not come from the display factor. This study confirms previous findings that medical-grade displays could be replaced by consumer-grade color displays with the same image quality.

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Bullet embolism is a rare complication of penetrating gunshots. We present a case of a 24-year-old man with a gunshot wound in the left scapular area, with no exit wound. Abdominal X-rays and a computed tomography (CT) scan suggested that the bullet was located within the intra-abdominal topography (intrahepatic), but laparotomy revealed no intra-abdominal injuries. After surgery, a sequential CT scan showed that the bullet had migrated to the right internal iliac vein (IIV). Venography confirmed the diagnosis of right IIV embolism and the decision was taken to attempt snare retrieval of the bullet, which was unsuccessful. It was therefore decided to leave the missile impacted inside the right IIV and the patient was put on oral anticoagulation. The patient recovered and was event free at 6 months' follow up.

Embolia balística é uma complicação rara de ferimentos por arma de fogo. Apresentamos um caso de um homem de 24 anos, vítima de um ferimento por arma de fogo em hemitórax posterior esquerdo (região escapular), sem orifício de saída. Radiografias e tomografia computadorizada do abdome evidenciaram um projétil em topografia intra-abdominal (intra-hepática); no entanto, a laparotomia exploradora demonstrou ausência de lesões intra-abdominais. Após a cirurgia, novo exame tomográfico revelou a migração da bala para a região da veia ilíaca interna (VII) direita. Realizada uma flebografia, esta confirmou a migração do projétil para a VII direita; tentou-se retirar o projétil durante o procedimento, sem sucesso. Optou-se, então, por deixá-la impactada na VII direita e manter o paciente em anticoagulação oral. O paciente evoluiu sem intercorrências até o sexto mês de seguimento.

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We evaluated a low cost device for digitizing X-ray films. It consisted of a locally-made wooden box and a readily-available digital camera. Two experienced paediatric radiologists interpreted the original X-ray films (the reference standard) and the corresponding images obtained in the photo light box. Ninety paediatric chest X-ray films were used (30 were normal chest radiographs, 30 showed pneumonic-consolidation and 30 had interstitial infiltrates). The presence or absence of the three signs most frequently found in acute respiratory pathologies were evaluated: normal pulmonary transparency, pneumonic consolidation and interstitial infiltration. There was very good agreement between the X-ray films and the digitized images, with kappa values from 0.86 to 0.98. There was good agreement between the two observers, with kappa values from 0.67 to 0.90. The low-cost photo light box represents an accessible and low-cost approach to transmitting X-ray images, allowing findings or a second opinion from a specialist radiologist to be obtained from a distance.

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PURPOSE: The main purpose of the present study was to determine the amounts of different tissues in the chest of the newborn patient (age ≤1 year), with the aim of developing a homogeneous phantom chest equivalent. This type of phantom is indispensable in the development of optimization procedures for radiographic techniques, including dosimetric control, which is a crucial aspect of pediatric radiology. The authors present a systematic set of procedures, including a computational algorithm, to estimate the amounts of tissues and thicknesses of the corresponding simulator material plates used to construct the phantom. METHODS: The Gaussian fit of computed tomographic (CT) analysis was applied to classify and quantify different biological tissues. The methodology is summarized with a computational algorithm, which was used to quantify tissues through automated CT analysis. The thicknesses of the equivalent homogeneous simulator material plates were determined to construct the phantom. RESULTS: A total of 180 retrospective CT examinations with anterior-posterior diameter values ranging 8.5-13.0 cm were examined. The amounts of different tissues were evaluated. The results provided elements to construct a phantom to simulate the infant chest in the posterior-anterior or anterior-posterior (PA/AP) view. CONCLUSIONS: To our knowledge, this report represents the first demonstration of an infant chest phantom dedicated to the radiology of children younger than one year. This phantom is a key element in the development of clinical charts for optimizing radiographic technique in pediatric patients. Optimization procedures for nonstandard patients were reported previously [Pina et al., Phys. Med. Biol. 49, N215-N226 (2004) and Pina et al., Appl. Radiat. Isot. 67, 61-69 (2009)]. The constructed phantom represents a starting point to obtain radiologic protocols for the infant patient.

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JUSTIFICATIVA E OBJETIVOS: Apresentação clínica de embolia pulmonar como edema agudo de pulmão é incomum em pacientes sem disfunção sistólica do ventrículo esquerdo.A fisiopatologia do edema agudo de pulmão não cardiogênico associado à embolia pulmonar não está claramente esclarecida.Possíveis mecanismos como aumento da permeabilidade capilar e hiperfluxo em áreas pulmonares com artérias não ocluídas parecemestar envolvidos. O objetivo deste estudo foi relatar um caso de paciente admitida com edema agudo de pulmão causado por embolia e infarto pulmonar.RELATO DO CASO: Paciente do sexo feminino, 67 anos,encaminhada à Sala de Emergência com dispneia súbita e ortopneia. À investigação complementar, radiografia de tórax mostrou edema pulmonar bilateral e a angiotomografia computadorizada revelou embolia associada a áreas de infarto pulmonar.CONCLUSÃO: O relato reforça a importância de incluir embolia pulmonar como um dos diagnósticos diferenciais em pacientes com edema agudo de pulmão de etiologia obscura.(AU)

BACKGROUND AND OBJECTIVES: Pulmonary embolism presenting as pulmonary edema is an uncommon condition in patients without left ventricular systolic dysfunction. Physiopathology of non cardiac pulmonary edema associated with pulmonary embolism is not entirely clear. Blood overflow in parenchymal areas with patent pulmonary arteries and increased capillary permeability are possible mechanisms involved. We report thecase of a patient with acute pulmonary edema caused by pulmonary embolism and infarction.CASE REPORT: Female patient, 67 year-old, referred to our hospital with sudden onset dyspnea and orthopnea. Chest radiography revealed bilateral pulmonary edema and computed tomographic arteriography detected pulmonary embolism associated with areas of pulmonary infarction.CONCLUSION: This report reinforces that pulmonary embolisms hould be considered as a differential diagnosis in acute pulmonary edema with unknown etiology.(AU)

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