Dengue Hemorrhagic Fever: A State-of-the-Art Review Focused in Pulmonary Involvement.

Dengue fever is an arboviral disease transmitted to humans through the bites of infected female Aedes mosquitoes. Dengue virus is a member of the Flaviviridae family, and human infection can be caused by any of the four antigenically distinct serotypes (DENV 1-4). The infection has become recognized as the most important and prevalent arboviral disease in humans, endemic in almost 100 countries worldwide. Nearly 3 billion people live in areas with transmission risk. Autochthonous transmission of the virus in previously disease-free areas, increased incidence in endemic areas, and epidemic resurgence in controlled regions could increase the risk of contracting more severe forms of the disease, such as dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). Symptomatic dengue virus infection can present with a wide range of clinical manifestations, from mild fever to life-threatening DSS. Thoracic complications may manifest as pleural effusion, pneumonitis, non-cardiogenic pulmonary edema, and hemorrhage/hemoptysis. No vaccine is currently available and no specific treatment for dengue fever exists, but prevention and prompt management of complications in patients with DHF can help reduce mortality. This review describes the main clinical, pathological, and imaging findings of thoracic involvement in DHF.

Pulmonary Leptospirosis With Diffuse Alveolar Hemorrhage: High-Resolution Computed Tomographic Findings in 16 Patients.

OBJECTIVE: The aim of this study was to evaluate the high-resolution computed tomographic (HRCT) findings from patients with leptospirosis and diffuse alveolar hemorrhage (DAH). MATERIALS AND METHODS: We retrospectively reviewed HRCT findings from 16 patients diagnosed as having leptospirosis causing DAH. The patient sample was composed of 13 men and 3 women aged 22 to 53 years (mean age, 34.5 years). Diagnosis was established with confirmation of leptospirosis infection by serologic microagglutination test. Histopathological study was performed in 8 patients. Two chest radiologists analyzed the HRCT images and reached decisions by consensus. RESULTS: The predominant HRCT findings were ground-glass opacities and airspace nodules (both n = 12, 75%), ground-glass nodules (n = 9, 56.25%), consolidations (n = 7, 43.75%), "crazy-paving" pattern (n = 3, 18.75%), and interlobular septal thickening without ground-glass opacity (n = 3, 18.75%). Bilateral pleural effusion was an associated finding in 2 (12.5%) patients. Analysis of the axial distribution of the lesions revealed diffuse distribution in 11 (68.75%) patients and peripheral lung zone predominance in 5 (31.25%) patients. Abnormalities were bilateral in all 16 (100%) patients. Analysis of the craniocaudal distribution of the lesions revealed lower zone predominance in 9 (56.25%) patients, diffuse distribution in 5 (31.25%) patients, middle zone predominance in 1 (6.25%) patient, and upper zone predominance in 1 (6.25%) patient. CONCLUSIONS: The most frequent HRCT findings in patients with leptospirosis causing DAH were ground-glass opacities, airspace nodules, ground-glass nodules, and consolidations. The lesions showed symmetrical distribution with lower zone predominance in most cases.

Differential diagnosis of diffuse alveolar haemorrhage in immunocompromised patients.

PURPOSE OF REVIEW: Diffuse alveolar haemorrhage (DAH) is a life-threatening medical emergency in immunocompromised and immunocompetent patients characterized by haemoptysis, anaemia, acute respiratory failure and diffuse pulmonary infiltrates on radiologic examination. This review describes DAH imaging features, causes and main differential diagnosis. RECENT FINDINGS: In immunosuppressed patients, DAH occurs most frequently in haematologic neoplasms, after haematopoietic stem cell transplantation or solid organ transplantation, secondary to drug reaction or infection, and associated with AIDS. However, differential diagnoses of all of these conditions include several conditions with similar findings. SUMMARY: Imaging patterns of DAH do not differ significantly from those of conditions included in the main differential diagnosis. The differential diagnosis depends on the patient's immunity status. In immunocompromised patients, infection and lung injury of other causes must be considered.

Respiratory Tract Amyloidosis. State-of-the-Art Review with a Focus on Pulmonary Involvement.

Amyloidosis is a constellation of disease entities characterized by abnormal extracellular deposition and accumulation of protein and protein derivatives, which show apple-green birefringence when stained with Congo red and viewed under polarized light. Amyloid can infiltrate virtually all organ systems and can display multiple and diverse imaging findings. Pathologically, respiratory involvement occurs in 50 % of patients with amyloidosis, and its clinical signs and symptoms vary depending on whether the disease is systemic or localized. The four main patterns of respiratory tract involvement are tracheobronchial, nodular parenchymal, diffuse alveolar septal, and lymphatic. Imaging findings of amyloidosis are nonspecific and vary in each pattern; knowledge about the disease impairment type is thus very important, and amyloidosis should be considered in the differential diagnosis of other very common diseases, such as infectious diseases, neoplasms, and vasculitis. This literature review describes the main clinical and imaging manifestations of amyloidosis, focusing on respiratory tract involvement and differential diagnosis.

Tuberous Sclerosis Complex: State-of-the-Art Review with a Focus on Pulmonary Involvement.

Tuberous sclerosis complex (TSC) is an autosomal-dominant neurocutaneous disease with high phenotypic variability. The incidence is approximately one in 5000-10,000 births. TSC is characterized by widespread hamartomas and benign or rarely malignant neoplasms affecting various organs, most commonly the brain, skin, retinas, kidneys, heart, and lungs. The wide range of organs affected reflects the roles of TSC1 and TSC2 genes in the regulation of cell proliferation and differentiation. Clinical diagnostic criteria are important because genetic testing does not identify the mutation in up to 25% of patients. Imaging is pivotal, as it allows a presumptive diagnosis of TSC and definition of the extent of the disease. Common manifestations of TSC include cortical tubers, subependymal nodules, white matter abnormalities, retinal abnormalities, cardiac rhabdomyoma, lymphangioleiomyomatosis (LAM), renal angiomyolipoma, and skin lesions. Pulmonary involvement consists of LAM and, less commonly, multifocal micronodular pneumocyte hyperplasia (MMPH), which causes cystic and nodular diseases, respectively. Recent reports indicate that pulmonary LAM is found by computed tomography in up to 35% of the female patients with TSC. MMPH is rare and may be associated with LAM or, less frequently, occurs as an isolated pulmonary manifestation in women with TSC. Dyspnea and pneumothorax are common clinical presentations of LAM, whereas MMPH is usually asymptomatic. The aim of this review is to describe the main clinical, imaging, and pathological aspects of TSC, with a focus on pulmonary involvement.

Lung cancer screening in Brazil: recommendations from the Brazilian Society of Thoracic Surgery, Brazilian Thoracic Association, and Brazilian College of Radiology and Diagnostic Imaging.

Although lung cancer (LC) is one of the most common and lethal tumors, only 15% of patients are diagnosed at an early stage. Smoking is still responsible for more than 85% of cases. Lung cancer screening (LCS) with low-dose CT (LDCT) reduces LC-related mortality by 20%, and that reduction reaches 38% when LCS by LDCT is combined with smoking cessation. In the last decade, a number of countries have adopted population-based LCS as a public health recommendation. Albeit still incipient, discussion on this topic in Brazil is becoming increasingly broad and necessary. With the aim of increasing knowledge and stimulating debate on LCS, the Brazilian Society of Thoracic Surgery, the Brazilian Thoracic Association, and the Brazilian College of Radiology and Diagnostic Imaging convened a panel of experts to prepare recommendations for LCS in Brazil. The recommendations presented here were based on a narrative review of the literature, with an emphasis on large population-based studies, systematic reviews, and the recommendations of international guidelines, and were developed after extensive discussion by the panel of experts. The following topics were reviewed: reasons for screening; general considerations about smoking; epidemiology of LC; eligibility criteria; incidental findings; granulomatous lesions; probabilistic models; minimum requirements for LDCT; volumetric acquisition; risks of screening; minimum structure and role of the multidisciplinary team; practice according to the Lung CT Screening Reporting and Data System; costs versus benefits of screening; and future perspectives for LCS.

Perfusion-weighted imaging in vestibular schwannoma: the influence that cystic status and tumor size have on perfusion profiles.

Objective: The perfusion profile of vestibular schwannomas (VSs) and the factors that influence it have yet to be determined. Materials and Methods: Twenty patients with sporadic VS were analyzed by calculating parameters related to the extravascular extracellular space (EES)-the volume transfer constant between a vessel and the EES (Ktrans); the EES volume per unit of tissue volume (Ve); and the rate transfer constant between EES and blood plasma (Kep)-as well as the relative cerebral blood volume (rCBV), and by correlating those parameters with the size of the tumor and its structure (solid, cystic, or heterogeneous). Results: Although Ktrans, Ve, and Kep were measurable in all tumors, rCBV was measurable only in large tumors. We detected a positive correlation between Ktrans and rCBV (r = 0.62, p = 0.031), a negative correlation between Ve and Kep (r = -0.51, p = 0.021), and a positive correlation between Ktrans and Ve only in solid VSs (r = 0.64, p = 0.048). Comparing the means for small and large VSs, we found that the former showed lower Ktrans (0.13 vs. 0.029, p < 0.001), higher Kep (0.68 vs. 0.46, p = 0.037), and lower Ve (0.45 vs. 0.83, p < 0.001). The mean Ktrans was lower in the cystic portions of cystic VSs than in their solid portions (0.14 vs. 0.32, p < 0.001), as was the mean Ve (0.37 vs. 0.78, p < 0.001). There were positive correlations between the solid and cystic portions for Ktrans (r = 0.71, p = 0.048) and Kep (r = 0.74, p = 0.037). Conclusion: In VS, tumor size appears to be consistently associated with perfusion values. In cystic VS, the cystic portions seem to have lower Ktrans and Ve than do the solid portions.

Objetivo: O perfil de perfusão do schwannoma vestibular (SV) não tem sido estudado, nem os fatores que o influenciam. Materiais e Métodos: Vinte pacientes com SV esporádico foram analisados usando Ktrans, Ve, Kep e rCBV e correlacionados com tamanho e estádio cístico. Resultados: Ktrans, Ve e Kep foram medidos em todos os casos. rCBV só foi possível em tumores grandes. Ktrans e rCBV estavam correlacionados positivamente (r = 0,62, p = 0, 0 31 ) . Ve e Kep estavam negativamente correlacionados (r = ­0,51, p = 0,021). Ktrans estava correlacionado positivamente com Ve em SVs sólidos (r = 0,64, p = 0,048). Em SVs pequenos, Ktrans foi menor (0,13 vs 0,029, p < 0,001), Kep foi maior (0,68 vs 0,46, p = 0,037) e Ve foi menor (0,45 vs 0,83, p < 0,001) que nos SVs grandes. Ktrans e Ve foram menores dentro dos cistos que nas porções solidas dos SVs císticos (0,14 vs 0,32, p < 0,001; 0,37 vs 0,78, p < 0.001, respectivamente). Foi encontrada correlação positiva em Ktrans (r = 0,71, p = 0,048) e Kep (r = 0,74, p = 0,037) entre as áreas sólidas e císticas. Conclusão: Nos SVs, o tamanho está consistentemente associado com os valores da perfusão. Nos SVs císticos, as porções císticas parecem ter valores menores de Ktrans e Ve do que nas porções sólidas.

Pixel-level annotated dataset of computed tomography angiography images of acute pulmonary embolism.

Pulmonary embolism has a high incidence and mortality, especially if undiagnosed. The examination of choice for diagnosing the disease is computed tomography pulmonary angiography. As many factors can lead to misinterpretations and diagnostic errors, different groups are utilizing deep learning methods to help improve this process. The diagnostic accuracy of these methods tends to increase by augmenting the training dataset. Deep learning methods can potentially benefit from the use of images acquired with devices from different vendors. To the best of our knowledge, we have developed the first public dataset annotated at the pixel and image levels and the first pixel-level annotated dataset to contain examinations performed with equipment from Toshiba and GE. This dataset includes 40 examinations, half performed with each piece of equipment, representing samples from two medical services. We also included measurements related to the cardiac and circulatory consequences of pulmonary embolism. We encourage the use of this dataset to develop, evaluate and compare the performance of new AI algorithms designed to diagnose PE.

Imaging findings of pulmonary contusions on multidetector CT: A retrospective study comparing adults and children.

To describe imaging findings of pulmonary contusions (PC) in adults and children using multidetector computed tomography (CT) scanners. We conducted a retrospective single center study. All chest multidetector computed tomography (MDCT) scans of victims of blunt trauma admitted to the emergency unit of a reference trauma center of Brazil between January 2015 and December 2016 were reviewed in search of opacities compatible with PC. The CT images were analyzed in conjunction with medical records, that provided demographic and clinical data. The obtained data were analyzed in the overall population and comparing children and adults. Significant P value was defined as <.05. 52.7% of patients presented bilateral opacities. Middle third, posterior and peripheral portions of the lungs were more frequently affected, in the craniocaudal, anteroposterior and axial axes, respectively. A vast majority of patients (80.6%) presented multiple opacities, whereas a minority showed subpleural sparing (26.9%) and fissure crossing (22.6%), with similar frequencies in children and adults. Children, although, more frequently presented consolidation and more diffuse lesions in the anteroposterior axis compared to adults, with statistically significant differences. PC usually are multiple and predominate in middle, posterior and peripheral portions of the lungs. Subpleural sparing and fissure crossing seems to be infrequent and have similar frequencies between children and adults. Although, there are differences between these age groups, as younger people tend to have more consolidation and diffuse opacities in the anteroposterior axis than older ones.

Assessment of risk factors in patients with rheumatoid arthritis-associated interstitial lung disease. / Avaliação de fatores de risco em pacientes com doença pulmonar intersticial associada à artrite reumatoide.

OBJECTIVE: To assess the risk factors for interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) and to evaluate the association of ILD with the use of methotrexate as well as with joint disease activity. METHODS: A retrospective, cross-sectional study conducted between March and December 2019 at a tertiary healthcare center, in a follow-up of RA patients who had undergone pulmonary function tests (PFT) and chest computed tomography. We evaluated the tomographic characteristics, such as the presence of ILD and its extension, as well as joint disease activity. Functional measurements, such as forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO), were also assessed. After this, a multivariate logistic regression analysis was applied in order to identify risk factors associated with ILD. RESULTS: We evaluated 1.233 patients, of which 134 were eligible for this study. The majority were female (89.6%), with a mean age of 61 years old and with a positive rheumatoid factor (86.2%). RA-associated ILD (RA-ILD) was detected in 49 patients (36.6%). We found an association of RA-ILD with age ≥= 62 year, male sex, smoking history and fine crackles in lung auscultation and a decreased DLCO. The indicators of being aged ≥ 62 years old and having moderate or high RA disease activity were both independent factors associated with RA-ILD, with an odds ratio of 4.36 and 3.03, respectively. The use of methotrexate was not associated with a higher prevalence of ILD. CONCLUSION: Age and RA disease activity are important risk factors associated with RA-ILD. Methotrexate was not associated with the development of RA-ILD in the present study.

OBJETIVO: Avaliar os fatores de risco para doença pulmonar intersticial (DPI) em pacientes com artrite reumatoide (AR), bem como a associação com uso de metotrexate e com a atividade da doença articular. MÉTODOS: Estudo retrospectivo, transversal, realizado entre março e dezembro de 2019 em um centro de saúde terciário, no seguimento de pacientes com AR submetidos a provas de função pulmonar (PFP) e tomografia computadorizada de tórax. Avaliamos as características tomográficas, como a presença de DPI e sua extensão, bem como a atividade da doença articular. Medidas funcionais, como capacidade vital forçada (CVF) e a medida de difusão de monóxido de carbono (DCO) também foram avaliadas. Em seguida, aplicou-se uma análise de regressão logística multivariada para identificar os fatores de risco associados à DPI. RESULTADOS: Foram avaliados 1.233 pacientes, dos quais 134 foram elegíveis para este estudo. A maioria era do sexo feminino (89,6%), com idade média de 61 anos e fator reumatoide positivo (86,2%). A DPI associada à AR (DPI-AR) foi detectada em 49 pacientes (36,6%). Encontramos associação de DPI-AR com idade ≥ 62 anos, sexo masculino, história de tabagismo,crepitações finas na ausculta pulmonar e diminuição da DCO. Idade ≥ 62 anos e atividade articular moderada ou alta da AR foram fatores independentes associados à DPI-AR, com odds ratio de 4,36 e 3,03, respectivamente. O uso de metotrexato não foi associado à maior prevalência de DPI. CONCLUSÃO: A idade e a atividade da doença da AR são importantes fatores de risco associados à DPI-AR. O metotrexato não foi associado ao desenvolvimento de DPI-AR no presente estudo.

Quantitative assessment of emphysema and bronchial wall thickness in patients with stable chronic obstructive pulmonary disease: comparison between the eosinophilic and non-eosinophilic phenotypes.

Objective: To perform a quantitative assessment of bronchial wall thickening and the emphysema score in patients with stable chronic obstructive pulmonary disease (COPD), comparing the eosinophilic and non-eosinophilic COPD phenotypes. Materials and Methods: This was a retrospective observational study of patients with COPD followed between August 2018 and July 2019. The patients were divided into two groups by the eosinophil count in peripheral blood: eosinophilic (≥ 300 cells/µL); and non-eosinophilic (< 300 cells/µL). Quantitative, automated assessments of emphysema and bronchial wall thickness were performed by evaluating computed tomography scans of the chest. Results: We evaluated the records of 110 patients diagnosed with COPD: 28 (25.5%) in the eosinophilic group; and 82 (74.5%) in the non-eosinophilic group. The demographic, clinical, functional, and therapeutic variables were comparable between the two groups. There were no significant differences between the two groups in terms of the emphysema score or bronchial wall thickness (p > 0.05 for both). Conclusion: Patients with eosinophilic COPD do not appear to have lower emphysema scores or greater bronchial wall thickening than do those with non-eosinophilic phenotypes of the disease.

Objetivo: Avaliar quantitativamente o escore de enfisema e o espessamento da parede brônquica de pacientes com doença pulmonar obstrutiva crônica (DPOC) estável e comparar os fenótipos eosinofílico e não eosinofílico. Materiais e Métodos: Estudo observacional, transversal, retrospectivo, que avaliou pacientes com DPOC no período de agosto de 2018 a julho de 2019. Os pacientes foram separados dois grupos, de acordo com o número de eosinófilos periféricos: os eosinofílicos (≥ 300 células/µL) e os não eosinofílicos (< 300 células/µL). Foram realizadas avaliações quantitativas e automatizadas de enfisema e de espessamento brônquico para os dois grupos por meio de tomografia computadorizada de tórax. Resultados: Foram coletados dados de 110 pacientes com o diagnóstico de DPOC, dos quais 28 (25,5%) apresentaram perfil eosinofílico. As variáveis demográficas, clínicas, funcionais e terapêuticas do grupo dos pacientes com perfil eosinofílico foram semelhantes às do grupo não eosinofílico. Não se observaram diferenças significativas em relação ao escore de enfisema e à medida de espessura de parede brônquica entre os dois grupos (p > 0,05). Conclusão: Neste estudo, os pacientes com fenótipo eosinofílico não apresentaram menor escore de enfisema e nem maior espessamento parietal brônquico.

Reversed halo sign in active pulmonary tuberculosis: criteria for differentiation from cryptogenic organizing pneumonia.

OBJECTIVE: The purpose of this study was to compare the morphologic characteristics of the "reversed halo" sign caused by tuberculosis with those caused by cryptogenic organizing pneumonia (COP) and to determine whether high-resolution CT (HRCT) can differentiate between these two conditions. MATERIALS AND METHODS: We retrospectively reviewed the HRCT scans of patients with the reversed halo sign caused by active tuberculosis and HRCT scans of patients with the reversed halo sign caused by COP. The study included 12 patients with active pulmonary tuberculosis (10 women and two men) and 10 patients with biopsy-proven COP (five women and five men). Tuberculosis was diagnosed by culture of sputum, bronchoalveolar lavage, or biopsy specimen. All patients underwent HRCT, and the images were reviewed by two chest radiologists who reached decisions by consensus. RESULTS: HRCT scans of all patients with active tuberculosis showed reversed halos with nodular walls; in most cases (10/12), we also observed nodules inside the halos. None of the HRCT scans of the COP cases reviewed had halos with nodular walls or nodules inside them. We also observed parenchymal abnormalities, such as consolidation, ground-glass, and linear opacities, associated with the reversed halo sign. Neither the number of reversed halo sign lesions nor the associated parenchymal lesions discriminated between tuberculosis and COP. Nevertheless, the association of the reversed halo sign with nodular walls or nodules inside the halo was seen only in tuberculosis patients. CONCLUSION: Although COP is considered the most frequent cause of the reversed halo sign, the presence of nodular walls or nodules inside the reversed halo strongly favors a diagnosis of active pulmonary tuberculosis rather than COP.

Brainstem hyperintensity in patients with vestibular schwannoma is associated with labyrinth signal on magnetic resonance imaging but not vestibulocochlear tests.

OBJECTIVES: Focal hyperintensity in the dorsal brainstem (HDB) has been described in large cerebellopontine angle tumours and is thought to represent vestibular nuclei degeneration, but its functional significance has not been thoroughly investigated. Our aim was to analyse its relationship to imaging characteristics of the tumour and inner-ear structures and to vestibulocochlear functional tests. METHODS: We retrospectively reviewed 54 patients with a histological diagnosis of vestibular schwannoma (VS). Magnetic resonance imaging tumour characteristics (size, cystic composition and distance from the cochlear aperture), signal intensity ratio of the cochlea and vestibule in fluid-attenuated inversion recovery (FLAIR) and fast imaging employing steady-state acquisition (FIESTA)/fast spin-echo imaging with variable flip angles (CUBE) and vestibulocochlear function tests (audiometry, auditory brainstem response (ABR) and video head impulse testing (vHIT)) were obtained. Statistical analyses were performed to evaluate their relation to focal HDB. RESULTS: Focal HDB was found in 22% of VS. It was significantly associated with large (p < 0.001) and cystic (p = 0.004) tumours and also with tumours located further from the cochlear aperture (p = 0.039). The signal intensity ratio of the cochlea on FLAIR was higher in patients with HDB (p < 0.014), but this difference was not observed in FIESTA/CUBE (p = 0.981). Audiometry, ABR and vHIT results did not significantly differ in patients with HDB, but ABR results were worse in patients with higher cochlear signal intensity on FLAIR sequences (p = 0.026). CONCLUSIONS: Focal HDB in patients with VS was associated with increased signal intensity ratio of the cochlea on FLAIR in patients with VS but not directly to the results of vestibulocochlear function tests.

Dosimetry and Comparison between Different CT Protocols (Low Dose, Ultralow Dose, and Conventional CT) for Lung Nodules' Detection in a Phantom.

BACKGROUND: The effects of dose reduction in lung nodule detection need better understanding. PURPOSE: To compare the detection rate of simulated lung nodules in a chest phantom using different computed tomography protocols, low dose (LD), ultralow dose (ULD), and conventional (CCT), and to quantify their respective amount of radiation. MATERIALS AND METHODS: A chest phantom containing 93 simulated lung nodules was scanned using five different protocols: ULD (80 kVp/30 mA), LD A (120 kVp/20 mA), LD B (100 kVp/30 mA), LD C (120 kVp/30 mA), and CCT (120 kVp/automatic mA). Four chest radiologists analyzed a selected image from each protocol and registered in diagrams the nodules they detected. Kruskal-Wallis and McNemar's tests were performed to determine the difference in nodule detection. Equivalent doses were estimated by placing thermoluminescent dosimeters on the surface and inside the phantom. RESULTS: There was no significant difference in lung nodules' detection when comparing ULD and LD protocols (p=0.208 to p=1.000), but there was a significant difference when comparing each one of those against CCT (p < 0.001). The detection rate of nodules with CT attenuation values lower than -600 HU was also different when comparing all protocols against CCT (p < 0.001 to p=0.007). There was at least moderate agreement between observers in all protocols (κ-value >0.41). Equivalent dose values ranged from 0.5 to 9 mSv. CONCLUSION: There is no significant difference in simulated lung nodules' detection when comparing ULD and LD protocols, but both differ from CCT, especially when considering lower-attenuating nodules.

Importance of chest HRCT in the diagnostic evaluation of fibrosing interstitial lung diseases.

Many conditions result in chronic interstitial lung disease (ILD), being classified as fibrosing ILDs, including idiopathic pulmonary fibrosis, connective tissue diseases, sarcoidosis, and fibrotic hypersensitivity pneumonitis. HRCT plays an important role in the clinical evaluation of fibrosing ILDs. Current treatment perspectives are encouraging and reinforce the need for HRCT scans of adequate technical quality for early detection of fibrosing ILD. Despite efforts in this regard, the significance and management of imaging findings of early interstitial lung abnormalities have yet to be clarified. After identification of CT findings consistent with fibrosing ILD, radiologists must be able to identify characteristic morphological patterns and, in some cases, features of specific clinical entities. In cases in which HRCT features are not sufficiently specific for a definitive diagnosis, HRCT can aid in selecting the best site for surgical lung biopsy. CT follow-up is useful for identifying progressive fibrosing ILDs and detecting complications unrelated to the underlying disease, including infections, acute exacerbations, and neoplasms. Automated quantification tools have clinical applicability and are likely to be available for use in imaging analysis in the near future. In addition, incorporation of CT evaluation into scoring systems based on clinical and functional parameters for staging fibrosing disease is likely to become valuable in determining prognosis. Knowledge of the clinical applications of CT evaluation is essential for specialists managing patients with fibrosing ILD and can have a positive impact on the clinical course of the disease.

Performance of ChatGPT on questions from the Brazilian College of Radiology annual resident evaluation test / Desempenho do ChatGPT nas questões da avaliação anual de residentes do Colégio Brasileiro de Radiologia

Abstract Objective: To test the performance of ChatGPT on radiology questions formulated by the Colégio Brasileiro de Radiologia (CBR, Brazilian College of Radiology), evaluating its failures and successes. Materials and Methods: 165 questions from the CBR annual resident assessment (2018, 2019, and 2022) were presented to ChatGPT. For statistical analysis, the questions were divided by the type of cognitive skills assessed (lower or higher order), by topic (physics or clinical), by subspecialty, by style (description of a clinical finding or sign, clinical management of a case, application of a concept, calculation/classification of findings, correlations between diseases, or anatomy), and by target academic year (all, second/third year, or third year only). Results: ChatGPT answered 88 (53.3%) of the questions correctly. It performed significantly better on the questions assessing lower-order cognitive skills than on those assessing higher-order cognitive skills, providing the correct answer on 38 (64.4%) of 59 questions and on only 50 (47.2%) of 106 questions, respectively (p = 0.01). The accuracy rate was significantly higher for physics questions than for clinical questions, correct answers being provided for 18 (90.0%) of 20 physics questions and for 70 (48.3%) of 145 clinical questions (p = 0.02). There was no significant difference in performance among the subspecialties or among the academic years (p > 0.05). Conclusion: Even without dedicated training in this field, ChatGPT demonstrates reasonable performance, albeit still insufficient for approval, on radiology questions formulated by the CBR.

Resumo Objetivo: Testar o desempenho do ChatGPT em questões de radiologia formuladas pelo Colégio Brasileiro de Radiologia (CBR), avaliando seus erros e acertos. Materiais e Métodos: 165 questões da avaliação anual dos residentes do CBR (2018, 2019 e 2022) foram apresentadas ao ChatGPT. Elas foram divididas, para análise estatística, em questões que avaliavam habilidades cognitivas de ordem superior ou inferior e de acordo com a subespecialidade, o tipo da questão (descrição de um achado clínico ou sinal, manejo clínico de um doente, aplicação de um conceito, cálculo ou classificação dos achados descritos, associação entre doenças ou anatomia) e o ano da residência (R1, R2 ou R3). Resultados: O ChatGPT acertou 53,3% das questões (88/165). Houve diferença estatística entre o desempenho em questões de ordem cognitiva inferior (64,4%; 38/59) e superior (47,2%; 50/106) (p = 0,01). Houve maior índice de acertos em física (90,0%; 18/20) do que em questões clínicas (48,3%; 70/145) (p = 0,02). Não houve diferença significativa de desempenho entre subespecialidades ou ano de residência (p > 0,05). Conclusão: Mesmo sem treinamento dedicado a essa área, o ChatGPT apresenta desempenho razoável, mas ainda insuficiente para aprovação, em questões de radiologia formuladas pelo CBR.

Lung cancer screening in Brazil: recommendations from the Brazilian Society of Thoracic Surgery, Brazilian Thoracic Association, and Brazilian College of Radiology and Diagnostic Imaging / Recomendações da Sociedade Brasileira de Cirurgia Torácica, Sociedade Brasileira de Pneumologia e Tisiologia e Colégio Brasileiro de Radiologia e Diagnóstico por Imagem para o rastreamento do câncer de pulmão no Brasil

ABSTRACT Although lung cancer (LC) is one of the most common and lethal tumors, only 15% of patients are diagnosed at an early stage. Smoking is still responsible for more than 85% of cases. Lung cancer screening (LCS) with low-dose CT (LDCT) reduces LC-related mortality by 20%, and that reduction reaches 38% when LCS by LDCT is combined with smoking cessation. In the last decade, a number of countries have adopted population-based LCS as a public health recommendation. Albeit still incipient, discussion on this topic in Brazil is becoming increasingly broad and necessary. With the aim of increasing knowledge and stimulating debate on LCS, the Brazilian Society of Thoracic Surgery, the Brazilian Thoracic Association, and the Brazilian College of Radiology and Diagnostic Imaging convened a panel of experts to prepare recommendations for LCS in Brazil. The recommendations presented here were based on a narrative review of the literature, with an emphasis on large population-based studies, systematic reviews, and the recommendations of international guidelines, and were developed after extensive discussion by the panel of experts. The following topics were reviewed: reasons for screening; general considerations about smoking; epidemiology of LC; eligibility criteria; incidental findings; granulomatous lesions; probabilistic models; minimum requirements for LDCT; volumetric acquisition; risks of screening; minimum structure and role of the multidisciplinary team; practice according to the Lung CT Screening Reporting and Data System; costs versus benefits of screening; and future perspectives for LCS.

RESUMO O câncer de pulmão (CP) é uma das neoplasias mais comuns e letais no Brasil, e apenas 15% dos pacientes são diagnosticados nos estágios iniciais. O tabagismo persiste como o responsável por mais de 85% de todos os casos. O rastreamento do CP (RCP) por meio da TC de baixa dosagem de radiação (TCBD) reduz a mortalidade do CP em 20%, e, quando combinado com a cessação do tabagismo, essa redução chega a 38%. Na última década, diversos países adotaram o RCP como recomendação de saúde populacional. No Brasil, embora ainda incipiente, a discussão sobre o tema é cada vez mais ampla e necessária. Com o intuito de aumentar o conhecimento e estimular o debate sobre o RCP, a Sociedade Brasileira de Cirurgia Torácica, a Sociedade Brasileira de Pneumologia e Tisiologia e o Colégio Brasileiro de Radiologia e Diagnóstico por Imagem constituíram um painel de especialistas para elaborar as recomendações para o RCP. As recomendações aqui apresentadas foram baseadas em revisão narrativa da literatura, com ênfase em grandes estudos populacionais, em revisões sistemáticas e em recomendações de diretrizes internacionais, sendo construídas após ampla discussão pelo grupo de especialistas. Os temas revisados foram os seguintes: porque rastrear, considerações gerais sobre tabagismo, epidemiologia do CP, critérios de elegibilidade, achados incidentais, lesões granulomatosas, modelos probabilísticos, requisitos mínimos da TCBD, aquisições volumétricas, riscos do rastreamento, estrutura mínima e papel da equipe multidisciplinar, conduta segundo o Lung CT Screening Reporting and Data System (Lung-RADS), custos vs. benefícios e perspectivas do rastreamento.

Perfusion-weighted imaging in vestibular schwannoma: the influence that cystic status and tumor size have on perfusion profiles / Perfusão por ressonância magnética em schwannoma vestibular: influência do tamanho e estádio cístico no perfil da perfusão

Abstract Objective: The perfusion profile of vestibular schwannomas (VSs) and the factors that influence it have yet to be determined. Materials and Methods: Twenty patients with sporadic VS were analyzed by calculating parameters related to the extravascular extracellular space (EES)—the volume transfer constant between a vessel and the EES (Ktrans); the EES volume per unit of tissue volume (Ve); and the rate transfer constant between EES and blood plasma (Kep)—as well as the relative cerebral blood volume (rCBV), and by correlating those parameters with the size of the tumor and its structure (solid, cystic, or heterogeneous). Results: Although Ktrans, Ve, and Kep were measurable in all tumors, rCBV was measurable only in large tumors. We detected a positive correlation between Ktrans and rCBV (r = 0.62, p = 0.031), a negative correlation between Ve and Kep (r = -0.51, p = 0.021), and a positive correlation between Ktrans and Ve only in solid VSs (r = 0.64, p = 0.048). Comparing the means for small and large VSs, we found that the former showed lower Ktrans (0.13 vs. 0.029, p < 0.001), higher Kep (0.68 vs. 0.46, p = 0.037), and lower Ve (0.45 vs. 0.83, p < 0.001). The mean Ktrans was lower in the cystic portions of cystic VSs than in their solid portions (0.14 vs. 0.32, p < 0.001), as was the mean Ve (0.37 vs. 0.78, p < 0.001). There were positive correlations between the solid and cystic portions for Ktrans (r = 0.71, p = 0.048) and Kep (r = 0.74, p = 0.037). Conclusion: In VS, tumor size appears to be consistently associated with perfusion values. In cystic VS, the cystic portions seem to have lower Ktrans and Ve than do the solid portions.

Resumo Objetivo: O perfil de perfusão do schwannoma vestibular (SV) não tem sido estudado, nem os fatores que o influenciam. Materiais e Métodos: Vinte pacientes com SV esporádico foram analisados usando Ktrans, Ve, Kep e rCBV e correlacionados com tamanho e estádio cístico. Resultados: Ktrans, Ve e Kep foram medidos em todos os casos. rCBV só foi possível em tumores grandes. Ktrans e rCBV estavam correlacionados positivamente (r = 0,62, p = 0, 0 31 ) . Ve e Kep estavam negativamente correlacionados (r = -0,51, p = 0,021). Ktrans estava correlacionado positivamente com Ve em SVs sólidos (r = 0,64, p = 0,048). Em SVs pequenos, Ktrans foi menor (0,13 vs 0,029, p < 0,001), Kep foi maior (0,68 vs 0,46, p = 0,037) e Ve foi menor (0,45 vs 0,83, p < 0,001) que nos SVs grandes. Ktrans e Ve foram menores dentro dos cistos que nas porções solidas dos SVs císticos (0,14 vs 0,32, p < 0,001; 0,37 vs 0,78, p < 0.001, respectivamente). Foi encontrada correlação positiva em Ktrans (r = 0,71, p = 0,048) e Kep (r = 0,74, p = 0,037) entre as áreas sólidas e císticas. Conclusão: Nos SVs, o tamanho está consistentemente associado com os valores da perfusão. Nos SVs císticos, as porções císticas parecem ter valores menores de Ktrans e Ve do que nas porções sólidas.

Pulmonary magnetic resonance imaging is similar to chest tomography in detecting inflammation in patients with systemic sclerosis.

Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are prevalent complications of systemic sclerosis (SSc) and are currently the leading causes of death related to the disease. The accurate recognition of these conditions is therefore of utmost importance for patient management. A study was carried out with 24 SSc patients being followed at the Rheumatology Department of the Hospital de Clínicas of Universidade Federal do Paraná (UFPR) and 14 healthy volunteers, with the objective of evaluating the usefulness of lung magnetic resonance imaging (MRI) when assessing ILD in SS patients. The results obtained with lung MRI were compared to those obtained by computed tomography (CT) of the chest, currently considered the examination of choice when investigating ILD in SS patients. The assessed population was predominantly composed of women with a mean age of 50 years, limited cutaneous SS, and a disease duration of approximately 7 years. In most cases, there was agreement between the findings on chest CT and lung MRI. Considering it is a radiation-free examination and capable of accurately identifying areas of lung tissue inflammatory involvement, lung MRI showed to be a useful examination, and further studies are needed to assess whether there is an advantage in using lung MRI instead of chest CT when assessing ILD activity in SS patients.