No abstract

The disease caused by the new coronavirus, or COVID-19, has been recently described and became a health issue worldwide. Its diagnosis of certainty is given by polymerase chain reaction. High-resolution computed tomography, however, is useful in the current context of pandemic, especially for the most severe cases, in assessing disease extent, possible differential diagnoses and searching complications. In patients with suspected clinical symptoms and typical imaging findings, in which there is still no laboratory test result, or polymerase chain reaction is not available, the role of this test is still discussed. In addition, it is important to note that part of the patients present false-negative laboratory tests, especially in initial cases, which can delay isolation, favoring the spread of the disease. Thus, knowledge about the COVID-19 and its imaging manifestations is extremely relevant for all physicians involved in the patient care, clinicians or radiologists.

PURPOSE This paper aims to present the results of a series of several Brazilian institutions that have been carrying out lung cancer screening (LCS). MATERIALS AND METHODS This is a retrospective, cohort study, with follow-up of individuals of both sexes, with a heavy smoking history, who participated in LCS programs between December 2013 and January 2021 in six Brazilian institutions located in the states of São Paulo, Rio Grande do Sul, and Bahia. RESULTS Three thousand four hundred seventy individuals were included, of which 59.8% were male (n = 2,074) and 50.6% were current smokers (n = 1,758), with 60.7 years (standard deviation 8.8 years). Lung-RADS 4 was observed in 233 (6.7%) patients. Biopsy was indicated by minimally invasive methods in 122 patients (3.5%). Two patients who demonstrated false-negative biopsies and lung cancer were diagnosed in follow-up. Diagnosis of lung cancer was observed in 74 patients (prevalence rate of 2.1%), with 52 (70.3%) in stage I or II. Granulomatous disease was found in 20 patients. There were no statistical differences in the incidence of lung cancer, biopsies, granulomatous disease, and Lung-RADS 4 nodules between public and private patients. CONCLUSION There are still many challenges and obstacles in the implementation of LCS in developing countries; however, our multi-institutional data were possible to obtain satisfactory results in these scenarios and to achieve similar results to the main international studies. Granulomatous diseases did not increase the number of lung biopsies. The authors hope that it could stimulate the creation of organized screening programs in regions still endemic for tuberculosis and other granulomatous diseases.

Objective The objective of this study was to assess the initial results of chest computed tomography (CT) standardized diagnostic criteria proposed by the Radiological Society of North America in coronavirus disease 2019 (COVID-19) compared with reverse transcription–polymerase chain reaction (RT-PCR). Methods Seventy-one patients who underwent RT-PCR test for COVID-19 and chest CT within an interval of 4 days or less were included. Seventy-five CTs were reviewed and classified as typical, indeterminate, or atypical appearance or negative for pneumonia by 2 radiologists. With RT-PCR as reference standard, the performance of the CT diagnostic criteria in diagnosing COVID-19 was assessed. Results The prevalence of positive RT-PCR was 45.1%. It was obtained a sensitivity of 83% (95% confidence interval [CI], 78%–89%), a specificity of 97% (95% CI, 92%–99%), an accuracy of 91% (95% CI, 85%–96%), a positive predictive value of 97% (95% CI, 91%–99%), and a negative predictive value of 86% (95% CI, 80%–92%). The diagnostic performance was excellent, considering the area under the curve of 0.92 (95% CI, 0.84–0.99). Conclusions Chest CT standardized diagnostic criteria had high specificity and positive predictive value for the diagnosis of COVID-19 when presenting a typical appearance.

The severity of pulmonary cystic involvement was mild in this sample of LAM patients and correlated best with airway obstruction, air trapping, reduced DLCO, the DDR index, and desaturation during the 6MWT. Serum VEGF-D cannot be completely defined as a valuable marker of disease severity and there may be a mechanism independent of MMPs to explain the formation of pulmonary cysts.