Diagnostic performance of artificial intelligence algorithms for detection of pulmonary involvement by COVID-19 based on portable radiography. / Rendimiento diagnóstico de algoritmos de inteligencia artificial para detección de compromiso pulmonar por COVID-19 basados en radiografía portátil.

INTRODUCTION AND OBJECTIVES: To evaluate the diagnostic performance of different artificial intelligence (AI) algorithms for the identification of pulmonary involvement by SARS-CoV-2 based on portable chest radiography (RX). MATERIAL AND METHODS: Prospective observational study that included patients admitted for suspected COVID-19 infection in a university hospital between July and November 2020. The reference standard of pulmonary involvement by SARS-CoV-2 comprised a positive PCR test and low-tract respiratory symptoms. RESULTS: 493 patients were included, 140 (28%) with positive PCR and 32 (7%) with SARS-CoV-2 pneumonia. The AI-B algorithm had the best diagnostic performance (areas under the ROC curve AI-B 0.73, vs. AI-A 0.51, vs. AI-C 0.57). Using a detection threshold greater than 55%, AI-B had greater diagnostic performance than the specialist [(area under the curve of 0.68 (95% CI 0.64-0.72), vs. 0.54 (95% CI 0.49-0.59)]. CONCLUSION: AI algorithms based on portable RX enabled a diagnostic performance comparable to human assessment for the detection of SARS-CoV-2 lung involvement.

COVID-19 pneumonia: Relationship between initial chest X-rays and laboratory findings.

OBJECTIVE: To analyze the initial findings in chest X-rays of patients with RT-PCR positive for SARS-CoV-2, and to determine whether there is a relationship between the severity of these findings and the clinical and laboratory findings. MATERIALS AND METHODS: This retrospective study analyzed the relationship between initial chest X-rays and initial laboratory tests in symptomatic adults with nasopharyngeal RT-PCR results positive for SARS-CoV-2 seen at our center between February 29 and March 23, 2020. Among other radiologic findings, we analyzed ground-glass opacities, consolidations, linear opacities, and pleural effusion. We also used a scale of radiologic severity to assess the distribution and extent of these findings. Among initial laboratory findings, we analyzed leukocytes, lymphocytes, platelets, neutrophil-to-lymphocyte ratio, and C-reactive protein. RESULTS: Of 761 symptomatic patients, 639 (84%) required hospitalization and 122 were discharged to their homes. The need for admission increased with increasing scores on the scale of radiologic severity. The extent of initial lung involvement was significantly associated with the laboratory parameters analyzed (P<.05 for platelets, P<.01 for lymphocytes, and P<.001 for the remaining parameters), as well as with the time from the onset of symptoms (P<.001). CONCLUSION: It can be useful to use a scale of radiologic severity to classify chest X-ray findings in diagnosing patients with COVID-19, because the greater the radiologic severity, the greater the need for hospitalization and the greater the alteration in laboratory parameters.

Usefulness of chest X-rays for evaluating prognosis in patients with COVID-19.

BACKGROUND AND AIMS: The pandemia caused by SARS-CoV-2 (COVID-19) has been a diagnostic challenge in which chest X-rays have had a key role. This study aimed to determine whether the Radiological Scale for Evaluating Hospital Admission (RSEHA) applied to chest X-rays of patients with COVID-19 when they present at the emergency department is related with the severity of COVID-19 in terms of the need for admission to the hospital, the need for admission to the intensive care unit (ICU), and/or mortality. MATERIAL AND METHODS: This retrospective study included 292 patients with COVID-19 who presented at the emergency department between March 16, 2020 and April 30, 2020. To standardize the radiologic patterns, we used the RSEHA, categorizing the radiologic pattern as mild, moderate, or severe. We analyzed the relationship between radiologic severity according to the RSEHA with the need for admission to the hospital, admission to the ICU, and mortality. RESULTS: Hospital admission was necessary in 91.4% of the patients. The RSEHA was significantly associated with the need for hospital admission (p = 0.03) and with the need for ICU admission (p < 0.001). A total of 51 (17.5%) patients died; of these, 57% had the severe pattern on the RSEHA. When we analyzed mortality by grouping patients according to their results on the RSEHA and their age range, the percentage of patients who died increased after age 70 years in patients classified as moderate or severe on the RSEHA. CONCLUSIONS: Chest X-rays in patients with COVID-19 obtained in the emergency department are useful for determining the prognosis in terms of admission to the hospital, admission to the ICU, and mortality; radiologic patterns categorized as severe on the RSEHA are associated with greater mortality and admission to the ICU.

Initial findings in chest X-rays as predictors of worsening lung infection in patients with COVID-19: correlation in 265 patients.

BACKGROUND AND AIMS: We aimed to analyze the relationship between the initial chest X-ray findings in patients with severe acute respiratory syndrome due to infection with SARS-CoV-2 and eventual clinical worsening and to compare three systems of quantifying these findings. MATERIAL AND METHODS: This retrospective study reviewed the clinical and radiological evolution of 265 adult patients with COVID-19 attended at our center between March 2020 and April 2020. We recorded data related to patients' comorbidities, hospital stay, and clinical worsening (admission to the ICU, intubation, and death). We used three scoring systems taking into consideration 6 or 8 lung fields (designated 6A, 6B, and 8) to quantify lung involvement in each patient's initial pathological chest X-ray and to classify its severity as mild, moderate, or severe, and we compared these three systems. We also recorded the presence of alveolar opacities and linear opacities (fundamentally linear atelectasis) in the first chest X-ray with pathologic findings. RESULTS: In the χ2 analysis, moderate or severe involvement in the three classification systems correlated with hospital admission (P = .009 in 6A, P = .001 in 6B, and P = .001 in 8) and with death (P = .02 in 6A, P = .01 in 6B, and P = .006 in 8). In the regression analysis, the most significant associations were 6B with alveolar involvement (OR 2.3; 95%CI 1.1.-4.7; P = .025;) and 8 with alveolar involvement (OR 2.07; 95% CI 1.01.-4.25; P = .046). No differences were observed in the ability of the three systems to predict clinical worsening by classifications of involvement in chest X-rays as moderate or severe. CONCLUSION: Moderate/severe extension in the three chest X-ray scoring systems evaluating the extent of involvement over 6 or 8 lung fields and the finding of alveolar opacities in the first pathologic X-ray correlated with mortality and the rate of hospitalization in the patients studied. No significant difference was found in the predictive ability of the three classification systems proposed.

COVID-19 pneumonia: relationship between initial chest X-rays and laboratory findings. / Neumonía COVID-19: relación entre la radiografía de tórax inicial y los datos analíticos.

OBJECTIVE: To analyze the initial findings in chest X-rays of patients with RT-PCR positive for SARS-CoV-2, and to determine whether there is a relationship between the severity of these findings and the clinical and laboratory findings. MATERIALS AND METHODS: This retrospective study analyzed the relationship between initial chest X-rays and initial laboratory tests in symptomatic adults with nasopharyngeal RT-PCR results positive for SARS-CoV-2 seen at our center between February 29 and March 23, 2020. Among other radiologic findings, we analyzed ground-glass opacities, consolidations, linear opacities, and pleural effusion. We also used a scale of radiologic severity to assess the distribution and extent of these findings. Among initial laboratory findings, we analyzed leukocytes, lymphocytes, platelets, neutrophil-to-lymphocyte ratio, and C-reactive protein. RESULTS: Of 761 symptomatic patients, 639 (84%) required hospitalization and 122 were discharged to their homes. The need for admission increased with increasing scores on the scale of radiologic severity. The extent of initial lung involvement was significantly associated with the laboratory parameters analyzed (p<0.05 for platelets, p<0.01 for lymphocytes, and p<0.001 for the remaining parameters), as well as with the time from the onset of symptoms (p<0.001). CONCLUSION: It can be useful to use a scale of radiologic severity to classify chest X-ray findings in diagnosing patients with COVID-19, because the greater the radiologic severity, the greater the need for hospitalization and the greater the alteration in laboratory parameters.

Usefulness of chest X-rays for evaluating prognosis in patients with COVID-19. / Utilidad de la radiografía de tórax para evaluar el pronóstico de pacientes con COVID-19.

BACKGROUND AND AIMS: The pandemia caused by SARS-CoV-2 (COVID-19) has been a diagnostic challenge in which chest X-rays have had a key role. This study aimed to determine whether the Radiological Scale for Evaluating Hospital Admission (RSEHA) applied to chest X-rays of patients with COVID-19 when they present at the emergency department is related with the severity of COVID-19 in terms of the need for admission to the hospital, the need for admission to the intensive care unit (ICU), and/or mortality. MATERIAL AND METHODS: This retrospective study included 292 patients with COVID-19 who presented at the emergency department between March 16, 2020 and April 30, 2020. To standardize the radiologic patterns, we used the RSEHA, categorizing the radiologic pattern as mild, moderate, or severe. We analyzed the relationship between radiologic severity according to the RSEHA with the need for admission to the hospital, admission to the ICU, and mortality. RESULTS: Hospital admission was necessary in 91.4% of the patients. The RSEHA was significantly associated with the need for hospital admission (p=0.03) and with the need for ICU admission (p<0.001). A total of 51 (17.5%) patients died; of these, 57% had the severe pattern on the RSEHA. When we analyzed mortality by grouping patients according to their results on the RSEHA and their age range, the percentage of patients who died increased after age 70 years in patients classified as moderate or severe on the RSEHA. CONCLUSIONS: Chest X-rays in patients with COVID-19 obtained in the emergency department are useful for determining the prognosis in terms of admission to the hospital, admission to the ICU, and mortality; radiologic patterns categorized as severe on the RSEHA are associated with greater mortality and admission to the ICU.

[Residual lesions on chest-Xray after SARS-CoV-2 pneumonia: Identification of risk factors]. / Lesiones residuales en radiografía simple de tórax tras neumonía por SARS-CoV-2: identificación de factores de riesgo.

INTRODUCTION: COVID-19 pneumonia is the most frequent clinical manifestation of this disease, and its long-term sequelae and possible progression to pulmonary fibrosis are still unknown. The aim of this study is a mid-term review of the sequelae on plain chest radiography (CXR) in patients with a previous diagnosis of COVID-19 pneumonia. PATIENTS AND METHODS: Retrospective review of patients with a diagnosis of COVID-19 pneumonia, assessing the persistence of residual lesions in the control CXR and analysing their possible relationship with epidemiological factors, risk factors, treatments received and initial radiological patterns. RESULTS: A total of 143 patients (52 women and 91 men) were analysed. Mean age was 64 years. Radiological complete resolution (CR) was observed in 104 (73%) and partial resolution (PR) in 39 (27%). Of the risk factors only age was significantly related to persistence of residual lesions (OR 1.06 CI 95% (1.02,1.10). In relation to treatments, significant differences were found with tocilizumab and glucocorticoids, where treated patients had a higher risk of residual lesions (OR 2.44 (1.03,5.80) and 3.05(1.43,6.51) respectively. In the analysis of radiological patterns, significant differences were observed in patients with peripheral condensations in the acute course and a pattern of early radiological worsening. A clinical-radiological dissociation was evident: 83% of patients with residual lesions had no respiratory symptoms. DISCUSSION: COVID19 pneumonias may have a slower radiological resolution in older patients with certain initial radiological patterns, but the development of pulmonary fibrosis in these patients is still questionable.

Radiological management and follow-up of post-COVID-19 patients. / Manejo y seguimiento radiológico del paciente post-COVID-19.

Most of the patients who overcome the SARS-CoV-2 infection do not present complications and do not require a specific follow-up, but a significant proportion (especially those with moderate / severe clinical forms of the disease) require clinicalradiological follow-up. Although there are hardly any references or clinical guidelines regarding the long-term follow-up of post-COVID-19 patients, radiological exams are being performed and monographic surveillance consultations are being set up in most of the hospitals to meet their needs. The purpose of this work is to share our experience in the management of the post-COVID-19 patient in two institutions thathave had a high incidence of COVID-19 and to propose general follow-uprecommendations from a clinical and radiological perspective.

Pediatric chest X-rays during the COVID-19 pandemic. / Radiografía de tórax pediátrica en la era COVID.

BACKGROUND: An infectious disease caused by a new type of coronavirus that can manifest as an acute respiratory infection was discovered in China in mid-December 2019 and soon spread throughout the country and to the rest of the world. Although chest X-rays are the initial imaging technique of choice for low respiratory infections with or without dyspnea, few articles have reported the radiologic findings in children with COVID-19. OBJECTIVE: To describe the clinical, laboratory, and chest X-ray findings in pediatric patients with signs and symptoms of respiratory infection attended at our hospital in March 2020. To analyze the frequency of COVID-19 compared to other respiratory infections, and to describe the radiologic manifestations of COVID-19 in pediatric patients. MATERIAL AND METHODS: This cross-sectional observational study included all children with clinical manifestations of respiratory infection (fever, rhinorrhea, cough, and/or dyspnea) that required chest X-rays in our hospital between March 1 and March 31. RESULTS: A total of 231 pediatric patients (90 (39%) girls and 141 (61%) boys; mean age, 4 y, range 1 month - 16 years) underwent chest X-rays for suspected respiratory infections. Most (88.4%) had mild symptoms; 29.9% had a family member positive for COVID-19 with symptoms similar to those of the patient. Nasal and/or throat swabs were analyzed for SARS-CoV-2 with PCR in the 47 (20.3%) children who presented at the emergency department; 3 (6.3%) of these were positive. Microbiological analyses were done in 85 (36.8%) of all patients, finding infections due to pathogens other than SARS-CoV-2 in 30 (35.3%). One of the patients with a PCR positive for SARS-CoV-2 had urine infection due to E. coli and blood culture positive for S. viridans. Abnormalities were observed on X-rays in 73.2% of the patients. Peribronchial thickening was the most common abnormal finding, observed in 57% of patients. Parenchymal consolidations were observed in 38.5%, being bilateral in 29.2% and associated with pleural effusion in 3.3%. The interstitial lines were thickened in 7.3%, and 7.3% had ground-glass opacities. CONCLUSION: During March 2020, COVID-19 and other symptomatic respiratory infections were observed. The radiologic pattern of these infections is nonspecific, and chest X-rays alone are insufficient for the diagnosis. Children with clinical manifestations compatible with COVID-19 (with or without PCR confirmation of infection by SARS-CoV-2) had mild symptoms and most did not require admission or invasive mechanical ventilation. In a context of community transmission, the absence of a known epidemiological antecedent should not be a contraindication for PCR to detect SARS-CoV-2.

Radiologic diagnosis of patients with COVID-19. / Diagnóstico radiológico del paciente con COVID-19.

The pandemia caused by the SARS-CoV-2 virus has triggered an unprecedented health and economic crisis. Although the diagnosis of infection with SARS-CoV-2 is microbiological, imaging techniques play an important role in supporting the diagnosis, grading the severity of disease, guiding treatment, detecting complications, and evaluating the response to treatment. The lungs are the main organ involved, and chest X-rays, whether obtained in conventional X-ray suites or with portable units, are the first-line imaging test because they are widely available and economical. Chest CT is more sensitive than plain chest X-rays, and CT studies make it possible to identify complications in addition to pulmonary involvement, as well as to suggestive alternative diagnoses. The most common radiologic findings in COVID-19 are airspace opacities (consolidations and/or ground-glass opacities), which are typically bilateral, peripheral, and located primarily in the lower fields.