Neumonía por COVID19: Valoración por imagen, lo básico / COVID­19 pneumonia: Imaging evaluation, the basics

La pandemia de COVID­19 ha resultado en una emergencia de salud global. Los estu­dios de imagen utilizados en esta enfermedad son la radiografía de tórax (RX) y la to­mografía computarizada (TC). Ambas modalidades tienen sus hallazgos descritos, pero no son específicos dado que muchas enfermedades pueden producir patrones simila­res, particularmente las neumonías virales. Los RX de tórax muestra hallazgos consis­tentes en opacidades alveolares las cuales son múltiples, periféricas, bilaterales y basales, mientras que la tomografía de tórax sus hallazgos más frecuentes son presen­cia de patrón en vidrio deslustrado, consolidaciones, engrosamiento septal, patrón en empedrado, dilatación bronquial y engrosamiento peri bronquial, broncograma, patrón de halo invertido y patrón de neumonía organizada. Los hallazgos por imagen depen­den del tiempo de evolución de la enfermedad ya que en etapas tempranas puede ser normal tanto en la RX como la TC. El riesgo de trombo embolismo pulmonar es alto y más frecuente que en pacientes con COVID­19 negativo

The COVID­19 pandemic has resulted in a global health emergency. The imaging stu­dies used in this disease are chest radiography (CXR) and computed tomography (CT). Both imaging modalities findings have had their findings. These findings described are not specific since many diseases can produce similar patterns. CXR shows somewhat consistent findings consisting of alveolar opacities which are multiple, peripheral, bilate­ral and basal, while CT the most frequent findings are the presence of grounded glass pattern, consolidations, septal thickening, crazy paving pattern, bronchial dilation and peribronchial thickening, air bronchograms, inverted halo sign and organized pneumo­nia. Imaging findings depends on the evolution time of the disease since in the early sta­ges both chest radiography and tomography may be normal. The risk for pulmonary embolism is high and more frequent than in patients with negative COVID­19

Radiological reports: a comparison between the transmission efficiency of information in free text and in structured reports

Introduction: This work proposes to improve the transmission of information between requiring physicians and radiologists. Objectives: Evaluate the implementation of a structured report (SR) in a university hospital. Methods: A model of a structured report for thyroid sonography was developed according to information gathered from radiologists and endocrinologists working in this field. The report was based on a web platform and installed as a part of a Radiological Information System (RIS) and a Hospital Information System (HIS). The time for the report generation under the two forms was evaluated over a four-month period, two months for each method. After this period, radiologists and requiring physicians were questioned about the two methods of reporting. Results: For free text, 98 sonograms were reported to have thyroids with nodules in an average time of 8.71 (+/-4.11) minutes, and 59 sonograms of thyroids without nodules were reported in an average time of 4.54 (+/- 3.97) minutes. For SR, 73 sonograms in an average time of 6.08 (+/-3.8) minutes for thyroids with nodules and 3.67 (+/-2.51) minutes for thyroids without nodules. Most of the radiologists (76.2 percent) preferred the SR, as originally created or with suggested changes. Among endocrinologists, 80 percent preferred the SR. Discussion: From the requiring physicians' perspective, the SR enabled standardization and improved information transmission. This information is valuable because physicians need reports prepared by radiologists. Conclusions: The implementation of a SR in a university hospital, under an RIS/HIS system, was viable. Radiologists and endocrinologists preferred the SR when compared to free text, and both agreed that the former improved the transmission of information.

Caracterização de lesões intersticiais de pulmão em radiograma de tórax utilizando análise local de textura / Characterization of interstitial lung lesions in chest radiograms using local texture analysis

OBJETIVO: Caracterizar lesões intersticiais em radiografias frontais de tórax, com base na análise de atributos estatísticos de textura, os quais permitem detectar sinais de anormalidades com natureza difusa. MATERIAIS E MÉTODOS: O esquema começa com a segmentação semi-automática dos campos pulmonares, sendo o contorno externo marcado manualmente, com posterior divisão automática de cada pulmão em seis regiões. O banco de imagens utilizado neste trabalho é composto por 482 regiões obtidas de exames contendo lesões e 324 regiões obtidas de exames normais. Os atributos de textura são extraídos automaticamente de cada uma dessas regiões e uma seleção das melhores combinações de atributos é feita através da distância Jeffries-Matusita. A classificação das regiões em normal ou suspeita é feita pela comparação com os k vizinhos mais próximos e o treinamento do classificador é baseado na técnica de treino e teste "half-half" e correlação cruzada. RESULTADOS: Os resultados obtidos foram analisados através do valor da área sob a curva ROC ("receiver operating characteristic"), a qual indica um sistema perfeito para uma área igual a 1. Os resultados forneceram uma área sob a curva ROC (A Z) igual a 0,887, com valores de sensibilidade igual a 0,804 e especificidade igual a 0,793. CONCLUSÃO: Os resultados indicam que o sistema de caracterização baseado em atributos de textura possui bom potencial para o auxílio ao diagnóstico de lesões intersticiais de pulmão.

OBJECTIVE: To characterize interstitial lesions in anterior-posterior chest X-rays based on the analysis of textural statistical features that allow the detection of abnormalities with diffuse pattern. MATERIALS AND METHODS: Image analysis begins with the semiautomatic segmentation of the lungs, marking the external contour of the lung manually followed by an automatic division of each lung in six regions. The data base of images used in this study consisted of 482 regions obtained from examinations in which lesions were detected and 324 regions from normal examinations. Textural features were automatically extracted from each area and the selection of the best set of features was made based on the Jeffries-Matusita distance. The regions were classified as normal or suspected using the k nearest-neighbor method and half-half, and cross-correlation methodologies were used for training the classifier. RESULTS: Results were assessed based on the value of the area under the ROC (receiver operating characteristic) curve that indicates an ideal response for an area equal to 1. The results showed an area under the ROC curve (AZ) of 0.887, sensitivity of 0.804, and specificity of 0.793. CONCLUSION: These results indicate that the implemented system has a good potential for computer-aided diagnosis of interstitial lung lesions.

Levantamento das condições de funcionamento dos serviços de radiologia de hospitais públicos e universitários do Rio de Janeiro / Evaluation of working conditions of radiology departments of public and university hospitals in Rio de Janeiro, Brazil

Foram realizados testes de controle de qualidade, descritos na Portaria 453/98 do Ministério da Saúde, em sete hospitais públicos do Rio de Janeiro, em um total de 29 tubos de raios X, 30 chassis e 20 vestimentas de proteção individual. Os testes avaliaram o desempenho do gerador de raios X e a geometria do feixe. Foram verificados, também, chassis, "écrans" e negatoscópios, assim como as câmaras claras e escuras. Alguns dos resultados encontrados foram: 55 por cento dos tubos foram reprovados em exatidão e 15 por cento em reprodutibilidade de kVp; 53 por cento foram reprovados em exatidão e 31 por cento em reprodutibilidade de tempo de exposição; 30 por cento foram reprovados em camada semi-redutora; 18 por cento foram reprovados no alinhamento do feixe central; 30 por cento foram reprovados em coincidência de campos; 40 por cento foram reprovados na linearidade de exposição; 64 por cento foram rejeitados no teste de ponto focal. Foram verificadas a guarda inadequada e a falta de recomendação para uso dos aventais plumbíferos. Os resultados dos testes sugerem a necessidade da implementação sistemática de controle de qualidade por um profissional qualificado. A relação de custo-benefício reforça a implantação e a manutenção dos procedimentos contidos e executados neste trabalho, pois tais procedimentos garantiriam a diminuição do custo final do serviço e da dose nos pacientes.

Quality control tests, according to "Portaria 453/98" of the Brazilian Health Ministry, were applied in seven public hospitals of Rio de Janeiro including 29 X-ray tubes, 30 cassettes and 20 individual protection garments. These tests evaluate mainly the X-ray generator and system geometry. Other tests in the accessories were also performed, such as: cassettes, screens, viewing boxes, darkrooms and clear rooms. In the kVp tests, 55% of the equipments were disapproved in exactitude and 15% in reproducibility. Time exactitude and reproducibility were not approved in 53% and 31% of the equipments, respectively. The percentages of disapprovement were: for the HVL (half-value layer) 30%, for beam alignment 18%, for field coincidence 30%, for exposure linearity 40% and for focal spot 64%. It has also been observed that frequently the lead aprons were not kept in appropriate hangers and this procedure may cause damage to these accessories. The results of the test suggest the need of implementation of quality assurance tests in these services. The cost benefit analysis of the results reinforces the importance of the implementation of the recommendations contained in this paper.