Thoracic asymmetries characterized by increased radiolucency of the lungs are important causes of morbidity in infants and children. Evaluation of affected patients frequently requires multiple imaging methods to diagnose the abnormality and to plan the surgical correction. The authors review and illustrate the characteristics of both common and rare thoracic asymmetries with emphasis on the radiological findings. The usefulness of different imaging methods in the diagnosis and treatment of these conditions is evaluated. The differential diagnosis as well the pitfalls and diagnostic difficulties are also discussed.

Keywords: Thoracic diseases, Congenital cystic adenomatoid malformation, Congenital lobar emphysema, Congenital diaphragmatic hernia

The authors report a case of lipoid pneumonia in an 80-year-old man with chronic constipation in regular use of mineral oil as a laxative. According to his family, he experienced coughing episodes when he took his medication. He also presented dyspnea at rest and diminished consciousness levels. Chest radiographs showed a consolidation area in the posterior segment of right upper lobe, which did not change on successive exams. High resolution computed tomography demonstrated low-density consolidation with negative Hounsfield units (-29 to -83 UH) and ground-glass opacities in the right upper lobe and inferior lobes. These opacities predominated in the posterior regions of the lungs. The diagnosis was confirmed by the presence of oil material on bronchoalveolar washing. The patient was advised to discontinue the ingestion of mineral oil and did not return for follow-up.

Keywords: Lipoid pneumonia, Computed tomography, Lungs

Complications from central venous catheterization include infectious conditions, pneumothorax, hemothorax and venous thrombosis. Pericardial effusion with cardiac tamponade hardly occurs, and in infants is generally caused by umbilical catheterization. The authors describe the case of cardiac tamponade occurred in an infant during chest computed tomography with contrast infusion through a central venous catheter inserted into the right internal jugular vein.

Keywords: Cardiac tamponade; Radiology; Thoracic surgery.

Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias.

Keywords: Magnetic resonance imaging; Diffusion-weighted imaging; Chest; Thoracic lesions; Oncology.

Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease.

Keywords: Computed tomography; Thoracic aorta; Aortic diseases; Atherosclerosis; Cardiovascular surgery.

In most cases of aspiration pneumonia in children, the disease is specific to this age group. Clinical and radiological correlation is essential for the diagnosis. The present pictorial essay is aimed at showing typical images of the most common etiologies.

Keywords: Pneumonia; Aspiration; Childhood.

OBJECTIVE: To identify and classify the radiographic patterns of megaesophagus in Chagas disease, as seen on esophagograms and chest X-rays. MATERIALS AND METHODS: This was a prospective study of 35 patients diagnosed with esophageal disease via manometry. The changes found on esophagograms were stratified according to Rezende's classification, divided into four categories (grades I through IV) determined by the degree of dilatation and impairement of esophageal motility. We subsequently correlated that ranking with the chest X-ray findings: gastric air bubble; air-fluid level; and mediastinal widening. RESULTS: Among the 35 patients, the esophageal disease was classified as grade I in 9 (25.7%), grade II in 3 (8.6%), grade III in 19 (54.3%), and grade IV in 4 (11.4%). None of the patients with grade I esophageal disease showed changes on chest X-rays. In two of the three patients with grade II disease, there was no gastric air-bubble, although there were no other findings in any of the grade II patients. Of the 19 patients with grade III disease, 15 had abnormal findings on X-rays. All four patients with grade IV disease showed abnormalities. CONCLUSION: The use of Rezende's classification is feasible, encompassing findings ranging from the subtle changes that characterize the initial phases of esophageal disease to the complete akinesia seen in dolicomegaesophagus. Chest X-ray findings are more common in patients with advanced stages of the disease and indicate the degree of esophageal involvement in Chagas disease.

Keywords: Esophageal achalasia/radiography; Esophagus/radiography; Radiography, thoracic.

OBJECTIVE: The aim of this study was to analyze the various computed tomography findings in penetrating chest trauma, as well as to determine the frequency and extent of the lesions. MATERIAL AND METHODS: We studied the computed tomography findings from 40 cases of penetrating thoracic trauma, of which 35 (85.8%) were gunshot wounds and 5 (14.2%) were caused by another type of weapon. RESULTS: Pulmonary lesions were found in 39 cases (97.5%), manifesting as contusions in 34 cases (85%), atelectasis in 8 (20%), lacerations in 1 (2.5%) and hematomas in 1 (2.5%). Hemothorax was seen in 31 cases (77.5%), and pneumothorax was seen in 22 cases (55%). Mediastinal lesions were observed in 8 cases (20%), including mediastinal hematoma in 3 cases (7.5%), hemopericardium in 3 (7.5%), and pneumomediastinum in 2 (5%). Diaphragmatic rupture was seen in 2 cases (5%). CONCLUSION: In patients with penetrating thoracic trauma, computed tomography of the chest is an important tool for characterizing the affected organs and evaluating the path of injury, as well as the severity and extent of the lesions. The images obtained are also useful in estimating the risk of death and determining the best therapeutic approach.

Keywords: Thoracic injuries; Wounds, penetrating; Tomography, X-ray computed.

OBJECTIVE: To evaluate chest X-ray findings in pediatric patients diagnosed with influenza A (H1N1) virus infection. MATERIALS AND METHODS: We retrospectively reviewed chest X-ray findings in 17 cases of pulmonary infection with the H1N1 virus (in 7 males and 10 females) examined between 2012 and 2016. The mean age of the patients was 14 months (range, 2–89 months). The diagnosis was established on the basis of clinical and radiographic criteria, and the virus was detected by polymerase chain reaction. The radiographic findings were categorized by type/pattern of opacity and by lung zone. The patients were divided into two groups: those not requiring ventilatory support; and those requiring ventilatory support or evolving to death. RESULTS: The abnormality most often seen on chest X-rays was that of peribronchovascular opacities, the majority of which affected less than 25% of the lung, the involvement being bilateral and asymmetric. The lung zone most frequently involved was the middle third, with central and peripheral distribution, without pleural effusion. There was a statistically significant difference between the groups in terms of the symmetry of pulmonary involvement, asymmetric findings predominating in the group that required ventilatory support (p = 0.029). CONCLUSION: In pediatric patients with H1N1 virus infection, the main alterations on the initial chest X-rays are peribronchovascular opacities, nonspecific alveolar opacities, and consolidations. Although the definitive diagnosis of H1N1 virus infection cannot be made on the basis of imaging characteristics alone, using a combination of clinical and radiographic findings can substantially improve the diagnostic accuracy.

Keywords: Influenza, human; Influenza A virus, H1N1 subtype; Radiography, thoracic.

Coronary arteries originating from the contralateral (noncoronary) sinus and having an interarterial course, in which they run from the ascending aorta to the pulmonary trunk, is a potentially fatal anomaly. Computed tomography (CT) angiography facilitates the recognition and therapeutic planning of such anomalies because of its ability to acquire high-resolution images of the entire course of the coronary artery, as well as of the accompanying atherosclerotic involvement. The right coronary artery originating from the left coronary sinus is the most prevalent anomaly of this type and usually implies a better prognosis, the interarterial course being classified as "high" or "low", depending on whether it is above or below the level of the pulmonary valve, with consequent stratification of the risk and the treatment. However, it is known that there is a high risk of sudden death among patients with a left coronary artery of anomalous origin from the right sinus. In such cases, surgical treatment is recommended, regardless of whether there are symptoms or evidence of ischemia. Given the importance of those aspects, which can be identified on CT of the chest or CT angiography of the aorta, this pictorial essay aims to illustrate such anomalies to facilitate their recognition and description by radiologists who are not specialists in cardiac imaging.

Keywords: Coronary vessel anomalies/complications; Coronary vessel anomalies/diagnostic imaging; Aorta, thoracic/abnormalities; Aorta, thoracic/diagnostic imaging.

OBJECTIVE: To evaluate the accuracy of chest computed tomography (CT) in patients with suspected severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) infection at a cancer center. Materials and METHODS: This retrospective single-center study selected 91 patients who had chest CT and real-time polymerase chain reaction (RT-PCR) test collected at the same day. CT results were classified in negative, typical, indeterminate or atypical findings. Diagnostic accuracy, sensitivity and specificity were calculated for two different scenarios: in the first, only typical findings on CT were considered positive; in the second, both typical and indeterminate findings were considered positive. RESULTS: Mean patients’ age was 58.2 years, most were male (60.4%) and had prior diagnosis of cancer (85.7%). CT showed typical findings in 28.6%, indeterminate findings in 24.2% and atypical findings in 26.4%. RT-PCR results were positive for SARS-CoV-2 in 27.5%. The sensitivity, specificity and accuracy in the first and second scenarios were respectively 64.0%, 84.8% and 79.1%, and 92.0%, 62.1% and 70.3%. CONCLUSION: CT has a high accuracy for the diagnosis of SARS-CoV-2 infection. Different interpretation criteria can provide either high sensitivity or high specificity. CT should be integrated as a triage test in resource-constrained environments during the pandemic to assist in the optimization of PCR-tests, isolation beds and intensive care units.

Keywords: Computed tomography; Severe acute respiratory syndrome; Coronavirus infections; Cancer.

OBJECTIVE: To establish the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) in discriminating malignant from non-malignant thoracic lymph nodes. MATERIALS AND METHODS: This was a meta-analysis involving systematic searches of the MEDLINE, EMBASE, and Web of Science databases up through April 2020. Studies reporting thoracic DWI and lymph node evaluation were included. The pooled sensitivity, specificity, diagnostic odds ratio, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS: We evaluated six studies, involving a collective total of 356 mediastinal lymph nodes in 214 patients. Thoracic DWI had a pooled sensitivity and specificity of 92% (95% confidence interval [95% CI]: 71–98%) and 93% (95% CI: 79–98%), respectively. The positive and negative likelihood ratios were 13.2 (95% CI: 4.0–43.8) and 0.09 (95% CI: 0.02–0.36), respectively. The diagnostic odds ratio was 149 (95% CI: 18–1,243), and the AUC was 0.97 (95% CI: 0.95–0.98). CONCLUSION: DWI is a reproducible technique and has demonstrated high accuracy for differentiating between malignant and benign states in thoracic lymph nodes.

Keywords: Diffusion magnetic resonance imaging; Lymphadenopathy; Lymph nodes/diagnostic imaging; Thoracic neoplasms/diagnosis; Magnetic resonance imaging; Meta-analysis.

Radiotherapy plays a central role in the palliative and curative treatment of neoplasms of the chest wall or intrathoracic structures. However, despite technical advances, radiotherapy can alter previously normal organs and tissues, those alterations presenting as various types of imaging findings. Post-radiation alterations must be promptly recognized by radiologists, in order to avoid confusion between complications of radiotherapy and the recurrence of a tumor. This pictorial essay aims to illustrate different thoracic changes after radiotherapy.

Keywords: Radiotherapy; Tomography, X-ray computed; Magnetic resonance imaging; Diagnostic imaging; Thoracic neoplasms.

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.

Keywords: Tomography, X-ray computed; Thoracic surgery, video-assisted; Lung neoplasms/diagnostic imaging.

Cystic echinococcosis (hydatid disease) is a zoonotic parasitic disease, caused by ingestion of Echinococcus granulosus eggs, that can result in cyst formation anywhere on the body. Hydatid disease is frequently seen in regions where there is human-animal contact and poor socioeconomic development. The prevalence of the disease ranges from 0 to 79 cases/100,000 population. Hydatid cysts are typically found in the liver and lungs, being less common in other parts of the body. Computed tomography or magnetic resonance imaging is often used in order to clarify the sites affected by a hydatid cyst, such as the cranial and thoracic regions, which also facilitates the surgical evaluation and minimizes complications. Although rare, hydatid cysts in atypical locations can provoke unusual complications, with unpredictable findings and symptoms. This essay discusses the radiological aspects of rare thoracic hydatid cysts.

Keywords: Echinococcosis/diagnostic imaging; Echinococcosis, pulmonary/diagnostic imaging; Thoracic diseases/diagnostic imaging; Tomography, X-ray computed; Magnetic resonance imaging.