"Pulmonary Vein Sign" for Pulmonary Embolism Diagnosis in Computed Tomography Angiography.

PURPOSES: Considering that pulmonary arterial obstruction decreases venous flow, we hypothesized that filling defects in pulmonary veins can be identified in areas adjacent to pulmonary embolism (PE). This sign was named the "pulmonary vein sign" (PVS), and we evaluated its prevalence and performance for PE diagnosis in computed tomography pulmonary angiography (CTPA). METHODS: This retrospective study enrolled consecutive patients with clinical suspicion of PE who underwent CTPA scan. The PVS was defined by the following criteria: (a) presence of a homogeneous filling defect of at least 2 cm in a pulmonary vein; (b) attenuation of the left atrium > 160 Hounsfield units. Using the cases that presented PE on CTPA as reference, sensitivity, specificity, and positive and negative predictive values were calculated for PVS. RESULTS: In total, 119 patients (73 female; mean age, 62 years) were included in this study. PE was diagnosed in 44 (35.8%) patients. The PVS was present in 16 out of 44 patients with PE. Sensitivity was 36.36% (95% confidence interval (CI) 22.83-52.26%); specificity, 98.67% (95% CI 91.79-99.93%); positive predictive value, 94.12% (95% CI 69.24-99.69%); negative predictive value, 72.55% (95% CI 62.67-80.70%). The Kappa index for the PVS was good (0.801; 95% CI 0.645-0.957). PVS was correlated with lobar and segmental pulmonary embolism (p < 0.01). CONCLUSION: Despite a low sensitivity, presence of the pulmonary vein sign was highly specific for PE, with a good agreement between readers. This sign could contribute for PE diagnosis on CTPA studies.

Advances in Imaging and Automated Quantification of Pulmonary Diseases in Non-neoplastic Diseases.

Histological examination has always been the gold standard for the detection and quantification of lung remodeling. However, this method has some limitations regarding the invasiveness of tissue acquisition. Quantitative imaging methods enable the acquisition of valuable information on lung structure and function without the removal of tissue from the body; thus, they are useful for disease identification and follow-up. This article reviews the various quantitative imaging modalities used currently for the non-invasive study of chronic obstructive pulmonary disease, asthma, and interstitial lung diseases. Some promising computer-aided diagnosis methods are also described.

Mediastinal lymph nodes and pulmonary nodules in children: MDCT findings in a cohort of healthy subjects.

OBJECTIVE: Existing data are very limited on incidentally detected pulmonary nodules or mediastinal lymph nodes in healthy children who undergo chest MDCT. We aimed to evaluate the prevalence, distribution, and average dimensions of these occasional findings in a cohort of otherwise healthy patients. MATERIALS AND METHODS: Two radiologists reviewed in consensus the scans of patients referred for chest MDCT during the preoperative workup for pectus carinatum or pectus excavatum treatments. Exclusion criteria included the presence of any documented malignancy (by date of MDCT or during the 2 years after the examination), history of recent infections, or trauma. Patients' records were assessed after 2 years for the development of any malignancy. RESULTS: A total of 99 individuals (63 boys, 36 girls; mean age, 13.5 years; range, 4-18 years) who fulfilled the study criteria were evaluated. The presence of at least one pulmonary nodule was observed in 75% of the patients, with a mean diameter of 2.8 mm. Of a total number of 225 pulmonary nodules, only 24 (10.7%) were calcified. Mediastinal lymph nodes were also identified in 81% of the cases, with a maximum diameter of 7 mm (smallest axis). CONCLUSION: The presence of pulmonary nodules or mediastinal lymph nodes on the basis of preoperative chest MDCT scans in healthy children is frequent. Given that 95% of the nodules and 100% of the lymph nodes measured less than 6 mm and 7 mm, respectively, we conclude that incidental findings under these limits are very unlikely to be pathologic.

Postoperative computed tomography of insufflated lung specimens obtained by video-assisted thoracic surgery: detection and margin assessment of pulmonary nodules.

Objective: To investigate the utility of computed tomography (CT) scans to detect and assess the margin status of pulmonary nodules that were insufflated after being resected by video-assisted thoracic surgery. Materials and Methods: This was a novel multicenter study conducted at two national referral centers for thoracic diseases. Patients suspected of having lung cancer underwent video-assisted thoracic surgery for the resection of pulmonary nodules, which were submitted to postoperative CT. Measurements from the CT scans were compared with the results of the histopathological analysis. Results: A total of 37 pulmonary nodules from 37 patients were evaluated. The mean age of the patients was 65 years (range, 36-84 years), and 27 (73%) were female. A CT analysis of insufflated specimens identified all 37 nodules, and 33 of those nodules were found to have tumor-free margins. The histopathological analysis revealed lung cancer in 30 of the nodules, all with tumor-free margins, and benign lesions in the seven remaining nodules. Conclusion: Postoperative CT of insufflated suspicious lung lesions provides real-time detection of pulmonary nodules and satisfactory assessment of tumor margins. This initial study shows that CT of insufflated lung lesions can be a valuable tool at centers where intraoperative histopathological analysis is unavailable.

Objetivo: Investigar a utilidade da tomografia computadorizada (TC) para a detecção e avaliação de margens de nódulos pulmonares que foram insuflados após ressecção por cirurgia torácica videoassistida. Materiais e Métodos: Um inédito estudo multicêntrico foi conduzido em dois centros de referência nacional para doenças torácicas. Nódulos foram ressecados por cirurgia torácica videoassistida de pacientes com suspeita de câncer de pulmão e submetidos a TC pós-operatória. As medidas radiológicas da TC foram comparadas com as da análise patológica. Resultados: Um total de 37 pacientes foi avaliado. A idade média foi de 65 anos (variação: 36-84 anos) e 27 indivíduos (73%) eram do sexo feminino. A análise por TC dos espécimes insuflados identificou todas as 37 lesões e 33 delas com margens livres. A análise patológica revelou 30 casos de câncer de pulmão, todos com margens livres, e sete lesões não malignas. Conclusão: A TC pós-operatória de lesões pulmonares insufladas com suspeita de malignidade provê detecção em tempo real de nódulos pulmonares e aceitável avaliação de margens tumorais. Este estudo inicial demonstra que a TC de lesões pulmonares insufladas pode ser uma ferramenta valiosa em centros em que a análise histopatológica intraoperatória é indisponível.

Postoperative computed tomography of insufflated lung specimens obtained by video-assisted thoracic surgery: detection and margin assessment of pulmonary nodules / Tomografia computadorizada pós-operatória de espécimes pulmonares insuflados após cirurgia torácica videoassistida: detecção e avaliação de margens de nódulos pulmonares

Abstract Objective: To investigate the utility of computed tomography (CT) scans to detect and assess the margin status of pulmonary nodules that were insufflated after being resected by video-assisted thoracic surgery. Materials and Methods: This was a novel multicenter study conducted at two national referral centers for thoracic diseases. Patients suspected of having lung cancer underwent video-assisted thoracic surgery for the resection of pulmonary nodules, which were submitted to postoperative CT. Measurements from the CT scans were compared with the results of the histopathological analysis. Results: A total of 37 pulmonary nodules from 37 patients were evaluated. The mean age of the patients was 65 years (range, 36-84 years), and 27 (73%) were female. A CT analysis of insufflated specimens identified all 37 nodules, and 33 of those nodules were found to have tumor-free margins. The histopathological analysis revealed lung cancer in 30 of the nodules, all with tumor-free margins, and benign lesions in the seven remaining nodules. Conclusion: Postoperative CT of insufflated suspicious lung lesions provides real-time detection of pulmonary nodules and satisfactory assessment of tumor margins. This initial study shows that CT of insufflated lung lesions can be a valuable tool at centers where intraoperative histopathological analysis is unavailable.

Resumo Objetivo: Investigar a utilidade da tomografia computadorizada (TC) para a detecção e avaliação de margens de nódulos pulmonares que foram insuflados após ressecção por cirurgia torácica videoassistida. Materiais e Métodos: Um inédito estudo multicêntrico foi conduzido em dois centros de referência nacional para doenças torácicas. Nódulos foram ressecados por cirurgia torácica videoassistida de pacientes com suspeita de câncer de pulmão e submetidos a TC pós-operatória. As medidas radiológicas da TC foram comparadas com as da análise patológica. Resultados: Um total de 37 pacientes foi avaliado. A idade média foi de 65 anos (variação: 36-84 anos) e 27 indivíduos (73%) eram do sexo feminino. A análise por TC dos espécimes insuflados identificou todas as 37 lesões e 33 delas com margens livres. A análise patológica revelou 30 casos de câncer de pulmão, todos com margens livres, e sete lesões não malignas. Conclusão: A TC pós-operatória de lesões pulmonares insufladas com suspeita de malignidade provê detecção em tempo real de nódulos pulmonares e aceitável avaliação de margens tumorais. Este estudo inicial demonstra que a TC de lesões pulmonares insufladas pode ser uma ferramenta valiosa em centros em que a análise histopatológica intraoperatória é indisponível.

The halo sign: HRCT findings in 85 patients.

OBJECTIVE:: The halo sign consists of an area of ground-glass opacity surrounding pulmonary lesions on chest CT scans. We compared immunocompetent and immunosuppressed patients in terms of halo sign features and sought to identify those of greatest diagnostic value. METHODS:: This was a retrospective study of CT scans performed at any of seven centers between January of 2011 and May of 2015. Patients were classified according to their immune status. Two thoracic radiologists reviewed the scans in order to determine the number of lesions, as well as their distribution, size, and contour, together with halo thickness and any other associated findings. RESULTS:: Of the 85 patients evaluated, 53 were immunocompetent and 32 were immunosuppressed. Of the 53 immunocompetent patients, 34 (64%) were diagnosed with primary neoplasm. Of the 32 immunosuppressed patients, 25 (78%) were diagnosed with aspergillosis. Multiple and randomly distributed lesions were more common in the immunosuppressed patients than in the immunocompetent patients (p < 0.001 for both). Halo thickness was found to be greater in the immunosuppressed patients (p < 0.05). CONCLUSIONS:: Etiologies of the halo sign differ markedly between immunocompetent and immunosuppressed patients. Although thicker halos are more likely to occur in patients with infectious diseases, the number and distribution of lesions should also be taken into account when evaluating patients presenting with the halo sign. OBJETIVO:: O sinal do halo consiste em uma área de opacidade em vidro fosco ao redor de lesões pulmonares em imagens de TC de tórax. Pacientes imunocompetentes e imunodeprimidos foram comparados quanto a características do sinal do halo a fim de identificar as de maior valor diagnóstico. MÉTODOS:: Estudo retrospectivo de tomografias realizadas em sete centros entre janeiro de 2011 e maio de 2015. Os pacientes foram classificados de acordo com seu estado imunológico. Dois radiologistas torácicos analisaram os exames a fim de determinar o número de lesões e sua distribuição, tamanho e contorno, bem como a espessura do halo e quaisquer outros achados associados. RESULTADOS:: Dos 85 pacientes avaliados, 53 eram imunocompetentes e 32 eram imunodeprimidos. Dos 53 pacientes imunocompetentes, 34 (64%) receberam diagnóstico de neoplasia primária. Dos 32 pacientes imunodeprimidos, 25 (78%) receberam diagnóstico de aspergilose. Lesões múltiplas e distribuídas aleatoriamente foram mais comuns nos imunodeprimidos do que nos imunocompetentes (p < 0,001 para ambas). A espessura do halo foi maior nos imunodeprimidos (p < 0,05). CONCLUSÕES:: As etiologias do sinal do halo em pacientes imunocompetentes são bastante diferentes das observadas em pacientes imunodeprimidos. Embora halos mais espessos ocorram mais provavelmente em pacientes com doenças infecciosas, o número e a distribuição das lesões também devem ser levados em conta na avaliação de pacientes que apresentem o sinal do halo.

Thoracic lymphadenopathy in benign diseases: A state of the art review.

Lymphadenopathy is a common radiological finding in many thoracic diseases and may be caused by a variety of infectious, inflammatory, and neoplastic conditions. This review aims to describe the patterns of mediastinal and hilar lymphadenopathy found in benign diseases in immunocompetent patients. Computed tomography is the method of choice for the evaluation of lymphadenopathy, as it is able to demonstrate increased size of individual nodes, abnormalities of the interface between the mediastinum and lung, invasion of surrounding fat, coalescence of adjacent nodes, obliteration of the mediastinal fat, and hypo- and hyperdensity in lymph nodes. Intravenous contrast enhancement may be needed to help distinguish nodes from vessels. The most frequent infections resulting in this finding are tuberculosis and fungal disease (particularly histoplasmosis and coccidioidomycosis). Sarcoidosis is a relatively frequent cause of lymphadenopathy in young adults, and can be distinguished from other diseases - especially when enlarged lymph nodes are found to be multiple and symmetrical. Other conditions discussed in this review are silicosis, drug reactions, amyloidosis, heart failure, Castleman's disease, viral infections, and chronic obstructive pulmonary disease.

PET/CT imaging in lung cancer: indications and findings.

The use of PET/CT imaging in the work-up and management of patients with lung cancer has greatly increased in recent decades. The ability to combine functional and anatomical information has equipped PET/CT to look into various aspects of lung cancer, allowing more precise disease staging and providing useful data during the characterization of indeterminate pulmonary nodules. In addition, the accuracy of PET/CT has been shown to be greater than is that of conventional modalities in some scenarios, making PET/CT a valuable noninvasive method for the investigation of lung cancer. However, the interpretation of PET/CT findings presents numerous pitfalls and potential confounders. Therefore, it is imperative for pulmonologists and radiologists to familiarize themselves with the most relevant indications for and limitations of PET/CT, seeking to protect their patients from unnecessary radiation exposure and inappropriate treatment. This review article aimed to summarize the basic principles, indications, cancer staging considerations, and future applications related to the use of PET/CT in lung cancer.

The effects of dynamic hyperinflation on CT emphysema measurements in patients with COPD.

OBJECTIVES: Dynamic hyperinflation (DH) significantly affects dyspnea and intolerance to exercise in patients with chronic obstructive pulmonary disease (COPD). Quantitative computed tomography (QCT) of the chest is the modality of choice for quantification of the extent of anatomical lung damage in patients with COPD. The purpose of this article is to assess the effects of DH on QCT measurements. METHODS: The study sample comprised patients with Global initiative for Chronic Obstructive Lung Disease (GOLD) stages III and IV COPD referred for chest CT. We examined differences in total lung volume (TLV), emphysema volume (EV), and emphysema index (EI) determined by QCT before and after DH induction by metronome-paced tachypnea (MPT). Initial (resting) and post-MPT CT examinations were performed with the same parameters. RESULTS: Images from 66 CT scans (33 patients) were evaluated. EV and EI, but not TLV, increased significantly (p<0.0001) after DH induction. CONCLUSION: QCT showed significant increases in EV and EI after MPT-induced DH in patients with GOLD stages III and IV COPD. For longitudinal assessment of patients with COPD using QCT, we recommend the application of a pre-examination rest period, as DH could mimic disease progression. QCT studies of the effects of DH-preventive therapy before exercise could expand our knowledge of effective measures to delay DH-related progression of COPD.

Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough.

OBJECTIVE: To assess the routine use of barium swallow study in patients with chronic cough. METHODS: Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks) were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons. RESULTS: The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6%) of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6%) of the patients, whereas the treatment was ineffective in 1 (8.4%). We observed no complications related to barium swallow, such as contrast aspiration. CONCLUSIONS: Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

Emphysema index in a cohort of patients with no recognizable lung disease: influence of age.

OBJECTIVE: To investigate the effects of age on pulmonary emphysema, based on the values of the emphysema index (EI) in a cohort of patients who had never smoked and who had no recognizable lung disease. METHODS: We reviewed the CT scans, reported as normal, of 315 patients. Exclusion criteria were a history of smoking, cardiorespiratory disease, and exposure to drugs that could cause lung disease. From this cohort, we selected 32 patients (16 men and 16 women), matched for gender and body mass index, who were divided equally into two groups by age (< 50 years and > 50 years). We quantified emphysema using a computer program specific to that task. The EI was calculated with a threshold of -950 HU. We also evaluated total lung volume (TLV) and mean lung density (MLD). RESULTS: The overall means for TLV, MLD, and EI were 5,027 mL, -827 HU, and 2.54%, respectively. Mean values in the older and younger groups, respectively, were as follows: for TLV, 5,229 mL vs. 4,824 mL (p > 0.05); for MLD, -846 HU vs. -813 HU (p < 0.04); and for EI, 3.30% vs. 1.28% (p < 0.001). Significant correlations were found between EI and age (r = 0.66; p = 0.001), EI and TLV (r = 0.58; p = 0.001), and EI and MLD (r = -0.67; p < 0.001). The predicted EI per age was defined by the regression equation (r² = 0.43): p50(EI) = 0.049 × age - 0.5353. CONCLUSIONS: It is important to consider the influence of age when quantifying emphysema in patients over 50 years of age. Based on the regression analysis, EI values of 2.6%, 3.5%, and 4.5% can be considered normal for patients 30, 50, and 70 years of age, respectively.

The halo sign: HRCT findings in 85 patients / Sinal do halo: achados de TCAR em 85 pacientes

ABSTRACT Objective: The halo sign consists of an area of ground-glass opacity surrounding pulmonary lesions on chest CT scans. We compared immunocompetent and immunosuppressed patients in terms of halo sign features and sought to identify those of greatest diagnostic value. Methods: This was a retrospective study of CT scans performed at any of seven centers between January of 2011 and May of 2015. Patients were classified according to their immune status. Two thoracic radiologists reviewed the scans in order to determine the number of lesions, as well as their distribution, size, and contour, together with halo thickness and any other associated findings. Results: Of the 85 patients evaluated, 53 were immunocompetent and 32 were immunosuppressed. Of the 53 immunocompetent patients, 34 (64%) were diagnosed with primary neoplasm. Of the 32 immunosuppressed patients, 25 (78%) were diagnosed with aspergillosis. Multiple and randomly distributed lesions were more common in the immunosuppressed patients than in the immunocompetent patients (p < 0.001 for both). Halo thickness was found to be greater in the immunosuppressed patients (p < 0.05). Conclusions: Etiologies of the halo sign differ markedly between immunocompetent and immunosuppressed patients. Although thicker halos are more likely to occur in patients with infectious diseases, the number and distribution of lesions should also be taken into account when evaluating patients presenting with the halo sign.

RESUMO Objetivo: O sinal do halo consiste em uma área de opacidade em vidro fosco ao redor de lesões pulmonares em imagens de TC de tórax. Pacientes imunocompetentes e imunodeprimidos foram comparados quanto a características do sinal do halo a fim de identificar as de maior valor diagnóstico. Métodos: Estudo retrospectivo de tomografias realizadas em sete centros entre janeiro de 2011 e maio de 2015. Os pacientes foram classificados de acordo com seu estado imunológico. Dois radiologistas torácicos analisaram os exames a fim de determinar o número de lesões e sua distribuição, tamanho e contorno, bem como a espessura do halo e quaisquer outros achados associados. Resultados: Dos 85 pacientes avaliados, 53 eram imunocompetentes e 32 eram imunodeprimidos. Dos 53 pacientes imunocompetentes, 34 (64%) receberam diagnóstico de neoplasia primária. Dos 32 pacientes imunodeprimidos, 25 (78%) receberam diagnóstico de aspergilose. Lesões múltiplas e distribuídas aleatoriamente foram mais comuns nos imunodeprimidos do que nos imunocompetentes (p < 0,001 para ambas). A espessura do halo foi maior nos imunodeprimidos (p < 0,05). Conclusões: As etiologias do sinal do halo em pacientes imunocompetentes são bastante diferentes das observadas em pacientes imunodeprimidos. Embora halos mais espessos ocorram mais provavelmente em pacientes com doenças infecciosas, o número e a distribuição das lesões também devem ser levados em conta na avaliação de pacientes que apresentem o sinal do halo.

PET/CT imaging in lung cancer: indications and findings / PET/TC em câncer de pulmão: indicações e achados

The use of PET/CT imaging in the work-up and management of patients with lung cancer has greatly increased in recent decades. The ability to combine functional and anatomical information has equipped PET/CT to look into various aspects of lung cancer, allowing more precise disease staging and providing useful data during the characterization of indeterminate pulmonary nodules. In addition, the accuracy of PET/CT has been shown to be greater than is that of conventional modalities in some scenarios, making PET/CT a valuable noninvasive method for the investigation of lung cancer. However, the interpretation of PET/CT findings presents numerous pitfalls and potential confounders. Therefore, it is imperative for pulmonologists and radiologists to familiarize themselves with the most relevant indications for and limitations of PET/CT, seeking to protect their patients from unnecessary radiation exposure and inappropriate treatment. This review article aimed to summarize the basic principles, indications, cancer staging considerations, and future applications related to the use of PET/CT in lung cancer.

O uso de PET/TC na avaliação e manejo de pacientes com câncer de pulmão aumentou substantivamente durante as últimas décadas. A capacidade de combinar informações funcionais e anatômicas permite a PET/TC analisar diversos aspectos do câncer de pulmão, desde um estadiamento mais preciso da doença até a capacidade de prover dados úteis na caracterização de nódulos pulmonares indeterminados. Além disso, a acurácia de PET/TC tem se demonstrado maior do que a de modalidades convencionais em alguns cenários, tornando a PET/CT um valioso método não invasivo para a investigação de câncer de pulmão. Entretanto, a interpretação dos achados de PET/TC apresenta numerosas armadilhas e potenciais fatores de confusão. Portanto, é imperativo que pneumologistas e radiologistas familiarizem-se com as principais indicações e limitações desse método, com o intuito de proteger os pacientes da exposição desnecessária à radiação e de terapias inapropriadas. Este artigo de revisão objetivou sumarizar os princípios básicos, indicações, considerações sobre o estadiamento tumoral e futuras aplicações de PET/TC em câncer de pulmão.