Negative Chest X-ray Research Articles

A ring-shaped gas sign: a case of the accidental ingestion of a press-through package.

This case report presents a common but instructive clinical scenario of accidental ingestion of a press-through package. Despite an initial negative chest X-ray and mild symptoms, the diagnosis was confirmed with additional computed tomography. The patient was eventually went through the successful endoscopic removal of the press-through package. Furthermore, a retrospective re-reviewing of the X-ray revealed a faint ring-shaped gas sign, characteristic of press-through package ingestion. This case underscores the intractableness to diagnosis of accidental ingestion of press-through package by only X-rays in real time and the potential role of computed tomography in ensuring timely diagnosis and treatment.

Etiological Spectrum of Lymphadenopathy Among Children on Lymph Node Biopsy.

Background Pediatric peripheral lymphadenopathy is commonly a benign condition and most cases resolve spontaneously; however, it can be a manifestation of a serious underlying disease. This study aimed to determine the etiological spectrum of persistent pediatric lymphadenopathy on excisional biopsy in a tertiary care children's hospital in a low-middle-income country and to make recommendations regarding evaluation, diagnostic testing, and surgical interventions best suited to the population. Methodology A prospective cross-sectionalstudy was conducted on 243 pediatric patients between the ages of one to 12 years undergoing excisional biopsy for persistent lymphadenopathy (more than four weeks duration) from April 1, 2021, to March 31, 2024. Patient demographic data along with signs, symptoms, and results of investigations including histopathological diagnosis were documented on a structured proforma. Results Patients' age range was two to 12 years (mean = 7.29 ± 2.30 years). The male-to-female ratio was 1:53. The Mean duration of lymphadenopathy was 35.89 ± 6.95 days (range = 25 to 57 days). The average size of lymph nodes ranged from 1 cm to a complex nodal mass of 7 cm. Histopathology showed reactive hyperplasia (40.32%, n = 98), tuberculosis (TB) (33.7%, n = 82), lymphoma (10.3%, n = 25), atypical mycobacterial adenitis (6.99%, n = 17), chronic granulomatous inflammation-histiocytosis (6.2%, n = 15), and Langerhans cell histiocytosis (2.5%, n = 6). The most common site was cervical. Sputum GeneXpert for TB had a true-positive rate of 78.84% while PPD was positive in only 13 TB patients. Atypical mycobacterial adenitis was successfully treated with excision and antibiotics. Supraclavicular nodes were strongly associated with lymphoma (p = 0.008). Conclusions Persistent pediatric lymphadenopathy is most commonly caused by TB followed by lymphoma. Positive sputum GeneXpert for TB with a suggestive clinical picture in endemic regions may be sufficient to start empiric therapy without the need for excisional biopsy in mycobacterial TB adenitis with negative PPD results and normal chest X-ray. In all other cases, excisional biopsy remains the gold standard for diagnosis. However, further studies should be conducted to formulate less invasive management algorithms.

Chest x-ray has low sensitivity to detect silicosis in artificial stone benchtop industry workers.

Chest x-ray (CXR) remains a core component of health monitoring guidelines for workers at risk of exposure to crystalline silica. There has however been a lack of evidence regarding the sensitivity of CXR to detect silicosis in artificial stone benchtop industry workers. Paired CXR and high-resolution computed tomography (HRCT) images were acquired from 110 artificial stone benchtop industry workers. Blinded to the clinical diagnosis, each CXR and HRCT was independently read by two thoracic radiologists from a panel of seven, in accordance with International Labour Office (ILO) methodology for CXR and International Classification of HRCT for Occupational and Environmental Respiratory Diseases. Accuracy of screening positive (ILO major category 1, 2 or 3) and negative (ILO major category 0) CXRs were compared with identification of radiological features of silicosis on HRCT. CXR was positive for silicosis in 27/110 (24.5%) workers and HRCT in 40/110 (36.4%). Of the 83 with a negative CXR (ILO category 0), 15 (18.1%) had silicosis on HRCT. All 11 workers with ILO category 2 or 3 CXRs had silicosis on HRCT. In 99 workers ILO category 0 or 1 CXRs, the sensitivity of screening positive CXR compared to silicosis identified by HRCT was 48% (95%CI 29-68) and specificity 97% (90-100). Compared to HRCT, sensitivity of CXR was low but specificity was high. Reliance on CXR for health monitoring would provide false reassurance for many workers, delay management and underestimate the prevalence of silicosis in the artificial stone benchtop industry.

ResfEANet: ResNet-fused External Attention Network for Tuberculosis Diagnosis using Chest X-ray Images

Pulmonary tuberculosis (TB), the most prevalent form of TB, remains a major global public health concern, contributing to more than a million deaths each year. The accurate and timely diagnosis of this disease is of paramount importance for effective control and treatment. Chest X-ray (CXR) images have emerged as a valuable tool for screening lung diseases, including TB, owing to their cost-effectiveness and non-invasiveness. Despite advancements in technology, the challenges associated with interpreting CXR images persist, primarily due to the scarcity of trained radiologists. This underscores the pressing need for an automated and cost-effective computer-aided system capable of diagnosing TB, assisting medical practitioners in distinguishing between TB-positive and negative CXR scans. In response to this need, we introduce an innovative approach called ResNet-fused External Attention Network (ResfEANet). This network excels in accurately classifying TB from CXR images, achieving remarkable levels of accuracy and sensitivity. ResfEANet is built upon ResNet and incorporates an External Attention mechanism, albeit with fewer residual network blocks than ResNet-50 resulting in a relatively shallow network with fewer layers. This approach proves highly effective in feature extraction and yields competitive results in the classification of TB. Our method was employed to train a model that demonstrated an impressive accuracy rate of 97.59% and a remarkable sensitivity of 100% in binary classification tasks with optimal computational cost. These outcomes suggest that our proposed approach has the potential to serve as a valuable secondary tool in clinical decision-making, providing crucial assistance to radiologists and healthcare professionals.

Ocular manifestations and diagnosis of tuberculosis involving the uvea: a case series

BackgroundOcular tuberculosis (TB) affects 1–2% of patients with TB, with TB uveitis being the most common. This series aims to look at different manifestations of tuberculosis associated uveitis and the different tests used to make a presumptive or definitive diagnosis.MethodsPatients diagnosed with TB related uveitis in Hong Kong SAR between 2017 and 2020 were reviewed. Demographics, clinical features, investigations and treatments of patients were collected.ResultsFifteen eyes in 10 patients with a mean age 57.30 ± 10.17 years were included. The ocular manifestations on presentation included anterior uveitis (50%), posterior uveitis (40%) and panuveitis (10%), where 70% of them were unilateral and 30% were bilaterally infected; on subsequent visits the manifestations further developed into posterior uveitis (40%), panuveitis (40%) and anterior uveitis (20%), where 50% of them were unilateral and 50% bilateral infected. Tuberculosis tests were positive in 5 out of 7 Mantoux tests, 4 out of 4 T-SPOT TB tests, 3 out of 4 QuantiFERON-TB gold tests, 1 out of 1 lymph node biopsy, 0 out of 9 chest x-rays, and no aqueous fluid polymerase chain reaction (PCR) was tested. Vision impairing complications were seen in 6 patients where retinal vasculitis was most commonly seen. With anti-TB treatment prescribed in 9 patients, side effects occurred in 5 patients, including ocular hypertension, disc swelling, and hepatitis.ConclusionsOcular TB infections may manifest in various forms, and can involve different parts of the eye. Bilateral involvement of TB is commonly presented, and both eyes should be evaluated at every follow up. When TB is suspected in a patient, diagnostic confirmation requires multimodal investigations where a negative chest x-ray is not useful in ruling out ocular TB infections, especially in an endemic region like Hong Kong. In these patients, it is crucial to have a high index of suspicion for TB, even when they do not demonstrate classical respiratory signs and symptoms of TB.

Associations of chest X-ray trajectories, smoking, and the risk of lung cancer in two population-based cohort studies.

Despite the increasing use of computed tomography (CT), chest X-ray (CXR) remains the first-line investigation for suspected lung cancer (LC) in primary care. However, the associations of CXR trajectories, smoking and LC risk remain unknown. A total of 52,486 participants from the PLCO and 22,194 participants from the NLST were included. The associations of CXR trajectories with LC risk were evaluated with multivariable COX regression models and pooled with meta-analyses. Further analyses were conducted to explore the stratified associations by smoking status and the factors associated with progression and regression in CXR. Compared to stable negative CXR (CXRSN), HRs (95%CIs) of LC incidence were 2.88(1.50-5.52), 3.86(2.03-7.35), and 1.08(0.80-1.46) for gain of positive CXR (CXRGP), stable positive CXR (CXRSP), and loss of positive CXR (CXRLP), while the risk of LC mortality were 1.58(1.33-1.87), 2.56(1.53-4.29), and 1.05(0.89-1.25). Similar trends were observed across different smoking status. However, LC risk with CXRGP overweighed that with CXRSP among ever smokers [2.95(2.25-3.88) vs. 2.59(1.33-5.02)] and current smokers [2.33(1.70-3.18) vs. 2.26(1.06-4.83)]. Moreover, compared to CXRSN among never smokers, even no progression in CXR, the HRs(95%CIs) of LC incidence were 7.39(5.60-9.75) and 31.45(23.58-41.95) for ever and current smokers, while risks of LC mortality were 6.30(5.07-7.81) and 27.17(21.65-34.11). If participants gained positive CXR, LC incidence risk significantly climbed to 22.04(15.37-31.60) and 71.97(48.82-106.09) for ever and current smokers, while LC mortality risk climbed to 11.90(8.58-16.50) and 38.92(27.04-56.02). CXRLP was associated with decreased LC risk. However, even smokers lost their positive CXR, and the increased risks of LC incidence and mortality did not decrease to non-significant level. Additionally, smoking was significantly associated with increased risk of CXRGP but not CXRLP. LC risk differed across CXR trajectories and would be modified by smoking status. Comprehensive intervention incorporating CXR trajectories and smoking status should be recommended to reduce LC risk.

Value of Thoracic CT in Blunt Trauma Patients With High Glasgow Coma Scale and Low Injury Severity Scale.

To determine the value of ordering a routine chest CT (CCT) in patients with blunt trauma presenting to the emergency department with a high GCS and low ISS, we retrospectively collected patient data including CT scan results, when physical examination and initial chest X-ray were normal in the trauma bay area. A retrospective data collection of 901 consecutive blunt trauma patients seen in the ED between 2017 and 2019 was analyzed. Data included physical examination, age, gender, current use of anticoagulation therapy, comorbid conditions, as well as the result of radiologic images, hospital length of stay, surgical intervention, and mortality. The patients were divided into two groups: group one (patients with negative physical examination; chest x-ray and CT) and group 2 (negative physical examination, positive or negative chest x-ray, and positive CT). Statistical analysis was performed using student's t-test and chi-square test. Of the 901 patients there were 489 (54%) males and 412 (46%) females with a mean age of 56 years. There were 461 patients who had a physical examination, chest x-ray, abdominal and CCT done. Group one included 442 (96%) patients, with negative physical examination, negative chest X-ray and CT scan. In group 2, 19 (4%) patients who had positive CT and or chest x-ray. Both groups were similar in GCS and ISS. Of the 19 patients, sixteen patients had a positive CCT, and thirteen of those had a positive chest x-ray. In the three patients who had negative physical examination and chest x-ray, the CT findings included one with a nondisplaced 10th rib fracture and two patients with osteoporotic compression fractures of dorsal vertebrae. The rate of both chest x-ray and CCT being positive among a group of screened patients was 16% (3/19) and the rate of a negative chest x-ray but positive CT was 16% (3/19). The odds ratio between the two outcomes was one. In blunt trauma patients presenting to the ED with a high GCS and low ISS score, when initial physical examination and chest x-ray are negative, routine CCT is of little value.

Utilization of a Guideline-recommended Imaging Paradigm for Pregnant Patients With Suspicion of Pulmonary Embolism.

A dose reduction imaging paradigm utilizing chest x-ray (CXR) to triage between computed tomography pulmonary angiography (CTPA) and lung scintigraphy (LS) was introduced in 2001 and adopted in 2012 by the American Thoracic Society/Society of Thoracic Radiology (ATS) guideline for the evaluation of pulmonary embolism in pregnancy. We aimed to assess the utilization of this imaging paradigm preadoption and postadoption by the ATS guideline, and identify factors associated with its utilization. This retrospective cohort study evaluated consecutive pregnant patients who received CTPA or LS for the evaluation of pulmonary embolism in pregnancy at 2 tertiary hospitals between September 2008 and March 2017, excluding 2012 for guideline release washout. Utilization of the imaging paradigm was defined per patient by the use of CXR before advanced imaging, with CTPA performed following positive CXR and LS performed following negative CXR. Multivariate analyses were performed to assess factors associated with utilization of the imaging paradigm. P <0.05 is considered significant. Overall, 9.8% (63/643) of studies utilized the dose reduction imaging paradigm, 13.3% (34/256) before the guidelines, and 7.5% (29/387) after. Multivariable analysis showed that the dose reduction imaging paradigm utilization was higher for inpatients (odds ratio [OR]: 4.5) and outpatients (OR: 3.1) relative to the emergency department patients, and lower for second (OR: 0.3) and third (OR: 0.2) trimester patients, without significant differences by study priority, patient age, or patient race. Guideline-recommended dose reduction imaging paradigm utilization was low, and decreased after guideline publication. Utilization varied by patient setting and trimester, which are potential targets for interventions to improve guideline compliance.

Evaluation of the use of GeneXpert MTB/RIF in a zone with high burden of tuberculosis in Thailand.

GeneXpert MTB/RIF is a reliable molecular diagnostic tool capable of detecting Mycobacterium tuberculosis (MTB) and identifying genetic determinants of rifampicin (RIF) resistance. This study aimed to assess physicians' diagnostic decision-making processes for TB based on GeneXpert MTB/RIF results and how this affected the initiation of multidrug resistance (MDR) treatment. This study employed a mixed method: data were collected retrospectively from the medical records of TB patients and in-depth interviews were conducted with healthcare workers in areas with a high TB burden in Thailand. A total of 2,030 complete TB records from 2 patient groups were reviewed, including 1443 suspected cases with negative smear results and 587 with high risk of MDR-TB. GeneXpert MTB/RIF was routinely used to assist the physicians in their decision-making for the diagnosis of pulmonary tuberculosis (PTB) and the initiation of MDR-TB treatment. The physicians used it as a "rule-in test" for all patients with negative chest X-rays (CXR) and smear results, to ensure timely treatment. Approximately one-fourth of the patients with negative CXR/smear and GeneXpert MTB/RIF results were diagnosed with PTB by the physicians, who based their decisions on other evidence, such as clinical symptoms, and did not use GeneXpert MTB/RIF as a "rule-out test." GeneXpert MTB/RIF proved effective in early detection within a day, thereby radically shortening the time required to initiate second-line drug treatment. Despite its high sensitivity for detecting PTB and MDR-TB, GeneXpert MTB/RIF had contradictory results (false positive and/or false negative) for 21.8% of cases among patients with negative smear results and 41.1% of cases among patients with high risk of MDR-TB. Therefore, physicians still used the results of other conventional tests in their decision-making process. It is recommended that GeneXpert MTB/RIF should be established at all points of care and be used as the initial test for PTB and MDR-TB diagnosis.

Usefulness of chest X-rays for detecting COVID 19 pneumonia during the SARS-CoV-2 pandemic

ObjectiveTo review the prognostic usefulness of chest X-rays in selecting patients with suspected SARS-CoV-2 infection. Material and methodsThis cross-sectional descriptive observational study analyzed 978 patients with suspected SARS-CoV-2 infections who underwent chest X-ray examinations in the emergency department of a tertiary hospital in March 2020. We separately analyzed demographic, clinical, and prognostic variables in two groups of patients: those in whom reverse-transcriptase polymerase chain reaction (RT-PCR) was done (n = 535) and those in whom RT-PCR was not done because of low clinical suspicion (n = 443). ResultsIn the group of patients with RT-PCR, the prevalence of SARS-CoV-2 was 70.4%, and the sensitivity of chest X-rays was 62.8%. In the group of patients without RT-PCR, chest X-rays were negative in 97.5%, corroborating the low clinical suspicion; these patients were discharged, and 5.6% of them reconsulted with mild forms of the disease. In the group of patients with RT-PCR, we observed no statistically significant differences in the percentage of pathologic chest X-rays between patients hospitalized in the ICU (72.9%) and in those hospitalized in other wards (68.3%) (p = 0.22). ConclusionIn the context of the pandemic, patients with low clinical suspicion and negative chest X-rays can be discharged with a low probability of reconsultation or of developing severe COVID19. In patients with RT-PCR positive for SARS-CoV-2, chest X-rays have no prognostic usefulness.

Radiography-based triage for COVID-19 in the Emergency Department in a Spanish cohort of patients

BackgroundStrategies to determine who could be safely discharged home from the Emergency Department (ED) in COVID-19 are needed to decongestion healthcare systems. ObjectivesTo describe the outcomes of an ED triage system for non-severe patients with suspected COVID-19 and possible pneumonia based on chest X-ray (CXR) upon admission. Material and methodsRetrospective, single-center study performed in Barcelona (Spain) during the COVID-19 peak in March–April 2020. Patients with COVID-19 symptoms and potential pneumonia, without respiratory insufficiency, with priority class IV–V (Andorran triage model) had a CXR upon admission. This approach tried to optimize resource use and to facilitate discharges. The results after adopting this organizational approach are reported. ResultsWe included 834 patients, 53% were female. Most patients were white (66%) or Hispanic (27%). CXR showed pneumonia in 523 (62.7%). Compared to those without pneumonia, patients with pneumonia were older (55 vs 46.6 years old) and had a higher Charlson comorbidity index (1.9 vs 1.3). Patients with pneumonia were at a higher risk for a combined outcome of admission and/or death (91 vs 12%). Death rates tended to be numerically higher in the pneumonia group (10 vs 1). Among patients without pneumonia in the initial CXR, 10% reconsulted (40% of them with new pneumonia). ConclusionCXR identified pneumonia in a significant number of patients. Those without pneumonia were mostly discharged. Mortality among patients with an initially negative CXR was low. CXR triage for pneumonia in non-severe COVID-19 patients in the ED can be an effective strategy to optimize resource use.

CT features of community-acquired pneumonia at the emergency department

BackgroundChest computed tomography (CT) was reported to improve the diagnosis of community-acquired pneumonia (CAP) as compared to chest X-ray (CXR). The aim of this study is to describe the CT-patterns of CAP in a large population visiting the emergency department and to see if some of them are more frequently missed on CXR. Materials and MethodsThis is an ancillary analysis of the prospective multicenter ESCAPED study including 319 patients. We selected the 163 definite or probable CAP based on adjudication committee classification; 147 available chest CT scans were reinterpreted by 3 chest radiologists to identify CAP patterns. These CT-patterns were correlated to epidemiological, biological and microbiological data, and compared between false negative and true positive CXR CAP. ResultsSix patterns were identified: lobar pneumonia (51/147, 35%), including 35 with plurifocal involvement; lobular pneumonia (43/147, 29%); unilobar infra-segmental consolidation (24/147, 16%); bronchiolitis (16/147, 11%), including 4 unilobar bronchiolitis; atelectasis and bronchial abnormalities (8/147, 5.5%); interstitial pneumonia (5/147, 3.5%). Bacteria were isolated in 41% of patients with lobar pneumonia-pattern (mostly Streptococcus pneumoniae and Mycoplasma pneumonia) versus 19% in other patients (p = 0.01). Respiratory viruses were equally distributed within all patterns. CXR was falsely negative in 46/147 (31%) patients. Lobar pneumonia was significantly less missed on CXR than other patterns (p = 0.003), especially lobular pneumonia and unilobar infra-segmental consolidation, missed in 35% and 58% of cases, respectively. ConclusionLobar and lobular pneumonias are the most frequent CT-patterns. Lobar pneumonia is appropriately detected on CXR and mainly due to Streptococcus pneumoniae or Mycoplasma pneumoniae. Chest CT is very useful to identify CAP in other CT-patterns. Prior the COVID pandemic, CAP was rarely responsible for interstitial opacities on CT.

710. Comparison of Initial CXR to CT in Patients (pts) with Hematologic Malignancy (HEM) and Documented Symptomatic Pulmonary Mucormycosis (PM)

BackgroundThere is a spectrum of pulmonary disease burden in pts with HEM and PM. There have not been any data comparing the sensitivity and findings of initial Chest X-Ray (CXR) and chest CT in these pts.MethodsWe compared the findings of the initial CXR and CT in all pts with proven or probable PM via EORTC/MSG criteria. We included only pts who had pulmonary symptoms and who had both CXR and CT within 5 days of each other and within seven days of symptom onset or date of culture at MD Anderson Cancer Center from April 2000 and April 2020. We collected data regarding demographics, status of HEM, clinical presentation, frequency and findings of BAL and imaging findings, mold-active prophylaxis and treatment regimens, and mortality. CXR findings were classified as normal or abnormal, and if abnormal sub-classified as mass-like/consolidative, nodular, cavitary or heterogenous/non-specific. CT findings were classified in a similar manner. ResultsWe Identified such 39 pts with PM who had both CXR and CT within 5 d. All pts had positive CT. Five pts (13%) had a negative CXR. The majority of pts 28 (72%) were neutropenic (neutrophil count < 500). The most common CXR findings were consolidation or mass-like lesions (56%), followed by patchy, heterogenous or non-specific findings (33%) and nodules (13%). Only 3% had cavitary lesions. Similarly, consolidation or mass-like lesions were the most common finding on CT (69%), followed by nodular lesions with or without ground glass halos (56%). Cavitary lesions and/or reverse halo sign (RHS) were common (31%) on CT. Patients with normal CXR vs those with abnormal CXR were comparable in all clinical parameters we collected. The median survival from time of symptoms onset for all pts was 45 days. There was a trend for lower 42 day mortality in pts with normal CXR (20% vs 47%, P=.253). ConclusionA negative CXR does not preclude PM, especially in neutropenic pts. A CT is recommended for better sensitivity and although there was concordance in CXR with CT findings in some chest abnormalities (mass, consolidation), CT more commonly revealed nodules and signs highly suggestive of PM such as RHS. Although small numbers precluded a robust comparison, it is possible that HEM pts with PM and negative initial CXR have better prognosis, perhaps reflecting a lower burden of pulmonary involvement Disclosures Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

367. Role of Conventional Biomarker for Prediction of Chest CT-confirmed COVID-19 Pneumonia

BackgroundThe coronavirus disease 2019 (COVID-19) has a wide range of severity. Chest computed tomography (CT) had high sensitivity and specificity to identify COVID-19 pneumonia. However, chest CT was not available in almost all hospitals in pandemic settings, including developed countries. This study is to evaluate the potential role of conventional inflammatory biomarkers to predict COVID-19 pneumonia.MethodsAll 155 RT-PCR-confirmed COVID-19 patients were evaluated for pneumonia by chest CT from April 10, 2021 to May 3, 2021 in the outpatient unit, a Thai university hospital. The inflammatory biomarkers were evaluated the sensitivity, specificity, LR+, LR-, and ROC to predict COVID-19 pneumonia.ResultsOf all 155 patients, pneumonia was diagnosed by chest CT in 117 patients. The pneumonia patients had a median (IQR) age of 38 (30, 55) years old. The BMI was higher in pneumonia than mild illness in 25.5 (22.0, 29.5) and 22.9 (19.4, 26.9) kg/m2, respectively (p=0.031). In univariate analysis, serum high-sensitivity C-reactive protein (hsCRP), lactate dehydrogenase (LDH), ferritin, total lymphocyte count (TLC), and albumin were associated with pneumonia, but the only hsCRP demonstrated association by multivariate analysis. The area under the ROC curves (AUC) was 0.82, 0.74, 0.68, 0.38, and 0.37 in hsCRP, LDH, ferritin, TLC, and albumin, respectively. The optimal cut-off level for CRP to diagnose COVID-19 pneumonia was 2.00 mg/L given sensitivity, specificity, LR+, LR- of 81.9%, 70.3%, 2.75, and 0.26 respectively (Figure 1 and Table 1).Table 1.Demonstrated sensitivity, specificity, LR+, and LR- for each specific cut-off value of hsCRPCut-off for hsCRP (≥ mg/L)Sensitivity (%)Specificity (%)LR+LR-1.9081.964.92.330.281.9581.967.62.530.272.00*81.970.32.750.262.0580.270.32.700.282.1080.270.32.700.28*Indicated optimal cut-off value for hsCRP to predict chest CT-confirmed pneumonia.ROC Curve of hsCRP to Diagnose of COVID-19 Pneumonia This figure shows ROC curve for hsCRP to diagnose of chest CT-confirmed COVID-19 pneumonia. The area under the ROC curve is 0.82. The optimal cut-off value for hsCRP is 2.00 given sensitivity of 81.9% and specificity of 70.3%.ConclusionThe hsCRP was the conventional biomarker that had an excellent performance in predicting COVID-19 pneumonia lead to early anti-SARS-CoV-2 treatment. This study demonstrated the potential role of hsCRP combined with clinical assessment in negative chest X-rays to replace chest CT in a high burden COVID-19 country during pandemic situations.Disclosures All Authors: No reported disclosures

Utilidad de la radiografía de tórax para la detección de neumonía COVID 19 durante la pandemia por SARS-CoV-2

ObjectiveTo review the prognostic usefulness of chest X-rays in selecting patients with suspected SARS-CoV-2 infection. Material and methodsThis cross-sectional descriptive observational study analyzed 978 patients with suspected SARS-CoV-2 infections who underwent chest X-ray examinations in the emergency department of a tertiary hospital in March 2020. We separately analyzed demographic, clinical, and prognostic variables in two groups of patients: those in whom reverse-transcriptase polymerase chain reaction (RT-PCR) was done (n=535) and those in whom RT-PCR was not done because of low clinical suspicion (n=443). ResultsIn the group of patients with RT-PCR, the prevalence of SARS-CoV-2 was 70.4%, and the sensitivity of chest X-rays was 62.8%. In the group of patients without RT-PCR, chest X-rays were negative in 97.5%, corroborating the low clinical suspicion; these patients were discharged, and 5.6% of them reconsulted with mild forms of the disease. In the group of patients with RT-PCR, we observed no statistically significant differences in the percentage of pathologic chest X-rays between patients hospitalized in the ICU (72.9%) and in those hospitalized in other wards (68.3%) (p=0.22). ConclusionIn the context of the pandemic, patients with low clinical suspicion and negative chest X-rays can be discharged with a low probability of reconsultation or of developing severe COVID19. In patients with RT-PCR positive for SARS-CoV-2, chest X-rays have no prognostic usefulness.

Value of a chest X-ray and CT to diagnose acute heart failure in acute patients with dyspnoea: a prospective comparative diagnostic study in the emergency department

Abstract Background and purpose Diagnosing heart failure (HF) remains difficult in the acute setting where multiple diagnoses are in play. Objective evidence of pulmonary congestion by chest X-ray (CXR) is one criteria for the recent universal definition of heart failure (UniHF). But, since CXR is known to have a low diagnostic value, we hypothesized that a chest CT (CT) would outdo the CXR to diagnose decompensated HF in acute breathless patients. This study's primary objective was to examine if the CT has higher accuracy than the CXR to diagnose HF in the acute setting; and, secondly, to identify what pre-test characteristics would predict a false negative CXR or CT. Methods We performed a single-centre, prospective observational study and included consecutive adult patients with dyspnoea in the emergency department. Patients underwent immediate clinical examination, blood tests, CXR, CT and an echocardiogram. Congestion on CXR and CT was defined as the congruent verdict by two expert thorax radiologists, blinded to each others reading and all other clinical data. The absence of congestion was defined as the congruent verdict of “no congestion”. Congestion of CXR and CT was held up against UniHF ascertained by an expert panel of cardiologists where the pulmonary congestion component primarily was based on elevated filling pressures from the simultaneous comprehensive echocardiogram. Univariate- and multivariate logistic analyses identified factors associated with a false negative chest x-ray and CT. Results Of 228 patients with a mean age of 74,5 years, 129 (56,5%) were male, 98 (43%) had UniHF, and 139 (61.0%) had pulmonary disease. Congestion on the CXR diagnosed UniHF with a 54% sensitivity and 95% specificity, with almost similar figures for the CT with 54% and 99% respectively. A marginally better performance of the CT was shown by a significantly lower Akaike Information Criterion for pulmonary congestion by CT than for CXR. However, the net reclassification improvement by CT was 4% (p:0.5586). The CXR and CT were false negative for UniHF in 46% (45/98) for both modalities (Table 1). The only independent pre-test predictor of a false negative radiology examination in multivariable logistic regression analysis was NT-proBNP (CXR: OR 1.670 per log(BNP), p: &amp;lt;0.001) and CT: OR 1.693 per log(BNP), p: &amp;lt;0.001). Conclusions For the first time, CT has been directly compared with CXR to diagnose HF in consecutive breathless patients from the emergency department. The chest CT was marginally more specific than the CXR to diagnose HF, but with a similar sensitivity. Approximately half the patients obeying the universal definition of HF have no definite congestion on CXR nor CT, and these can only be identified by a high proBNP. Funding Acknowledgement Type of funding sources: None. Table 1

DISSEMINATED TB IN A PREGNANT PATIENT

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: In the United States, most cases occur in foreign-born individuals immigrating from countries with high rates of endemic TB [1]. Aggressive dissemination of tuberculosis related to pregnancy is rarely reported in the literature; the incidence of TB in pregnancy ranges between 1 and 2% [2, 3]. We report a pregnant patient with the dissemination of tuberculosis who developed CNS symptoms and was found to have numerous brain tuberculomas. CASE PRESENTATION: A 33-year-old F P1001 25+5wga, HIV-negative Haitian woman, presented with a non-productive cough and right lower quadrant pain. Patient-reported recent travel to Haiti and history of positive quantiferon test noted during the prenatal period with subsequent negative chest x-ray screening.Initially, during the admission, she started to have low-grade fevers and was saturating 96% on room air. Labs were significant for elevated LFTs and ALK-PHOS. Initial chest x-ray showed bilateral infiltrates. A follow-up chest-CT demonstrated diffuse reticulonodular pattern bilaterally with no lymphadenopathy. There was a concern for multi-systemic sarcoidosis. ACE and 1,25-(OH)2 Vitamin D levels were elevated.The hospital course was complicated by new-onset lethargy and the development of late fetal decelerations, resulting in an emergent caesarian section. Pulse dose steroids were given for presumed multisystemic sarcoidosis.Three days post-delivery, the patient endorsed persistent headaches. An acute change in mentation was noted on the neurological exam, raising concern for a CNS infection. CT head revealed non-obstructive hydrocephalus and hypodensities in the bilateral parietal regions. Follow-up MRI showed ring-enhancing lesions, along with cerebral vasculitis seen on MRA. The pathology report from the placental tissue showed necrotizing granulomatous inflammation and an abundance of acid-fast bacillus. Emergently, the patient was started on treatment for tuberculomas of the brain. DISCUSSION: Meningitis and tuberculoma are the two most common forms of intracranial tuberculosis [4]. CNS TB is uncommon in HIV-negative patients [5]. The pathogenesis of TB of the brain initially starts with a rupture of rich focus into the subarachnoid space, heralding the onset of meningitis. The subsequent development of adhesions results in neurological sequelae [6]. Cerebral imaging is essential to establish the diagnosis of and disclose hydrocephalus, basilar meningeal thickening, and tuberculomas [3]. CONCLUSIONS: Although a multidisciplinary approach was taken, we feel that the administration of pulse dose steroids allowed the reactivation of disseminated TB, ultimately resulting in our patient's demise. REFERENCE #1: Amin S, Stone D, Anderlind C. A 32-Year-Old Woman With Miscarriage, Headache, Hepatitis, and Pulmonary Disease. Chest. 2019 Apr;155(4):e101-e105. doi: 10.1016/j.chest.2018.10.001. PMID: 30955580. DISCLOSURES: No relevant relationships by Rosa Arancibia, source=Web Response No relevant relationships by Felicia Canaday, source=Web Response No relevant relationships by Andrew Doodnauth, source=Web Response No relevant relationships by Khawaja Omar, source=Web Response

Repeat SARS-CoV-2 testing after recovery. Is a pretransplant PCR necessary?

The emergence of SARS-CoV-2 and the clinical syndrome of COVID19 resulted in a major decrease in transplant volumes during the first months of the pandemic followed by a change in practice, with strict screening and SARS-CoV-2 PCR testing prior to transplant. Protocols required a negative SARS-CoV-2 PCR prior to proceeding with transplantation. Many transplants were delayed nationwide due to persistent positive PCRs in asymptomatic patients, sometimes for months (1).

Evaluating current chest imaging practices of pediatric patients with COVID-19: A retrospective analysis

PurposeThis retrospective analysis aims to examine the effectiveness of the current chest imaging guidelines regarding COVID-19 positive pediatric patients on our study group of patients aged 0 to 18. Materials and methodsWe examined clinical and imaging data of 178 pediatric COVID-19 positive patients confirmed by PCR admitted to the Children's Hospital of Los Angeles between March 6, 2020 and June 23, 2020. ResultsOf 178 patients, only 46 (27%) patients underwent any form of chest imaging. Thirteen (28%) of 46 imaged patients had positive chest X-rays (CXR) or computed tomography (CT) chest findings, with 8 (62%) of the 13 patients suggesting pneumonia or multifocal pneumonia, 3 (23%) patients having acute respiratory distress syndrome, and 2 (15%) patients demonstrating left sided pleural effusions thought to be the result of ruptured appendicitis unrelated to their COVID-19 diagnosis. All but one patient had significant prior medical histories with an associated comorbid medical condition. Of the 46 imaged patients, 17 (37%) patients had a negative chest X-ray, and 15 (33%) patients had suggestive findings of viral etiology. 132 patients were not imaged. ConclusionOur study population corroborated current chest imaging guidelines in pediatric patients. Chest imaging modalities such as CXR and CT should be reserved for patients who are severely symptomatic and/or possess prior comorbidities such as immunosuppression, diabetes, asthma, obesity, or where other differential etiologies must be entertained.

Chest computed tomography and chest X-ray in the diagnosis of community-acquired pneumonia: a retrospective observational study.

ObjectivesTo compare the yield of early combined use of chest X-ray (CXR) and chest computed tomography (CT) in patients diagnosed with community-acquired pneumonia (CAP) presenting to the emergency department (ED) and assess the impact of chest CT on the initial diagnosis.MethodsThe medical records of 900 patients who presented to the ED and were diagnosed with CAP over a 1-year period were reviewed, and 130 patients who underwent CXR and chest CT within 48 hours were selected. CXR findings were classified as positive, negative, or inconclusive for CAP. Chest CT findings were defined as positive, negative, inconclusive, or positive with add-on to the CXR findings. CT was classified as having no benefit, large benefit, or moderate benefit based on the chest CT and CXR findings.ResultsChest CT results were positive in 90.7% of patients, with 41.5% being newly diagnosed after negative or inconclusive CXR and 21.5% being diagnosed with add-on to the CXR findings. CT had large, moderate, and no benefit over CXR in diagnosing or excluding CAP in 45.3%, 21.5%, and 33.1% of patients, respectively.ConclusionEarly chest CT may be used to compliment CXR in the early diagnosis of CAP among patients in the ED.