scholarly journals Multireader Evaluation of Radiologist Performance for COVID-19 Detection on Emergency Department Chest Radiographs

2021 ◽  
Author(s):  
Judy W. Gichoya ◽  
Priyanshu Sinha ◽  
Melissa Davis ◽  
Jeffrey W. Dunkle ◽  
Scott A. Hamlin ◽  
...  
Keyword(s):  
Emergency Department ◽  
Endotracheal Tube ◽  
Clinical History ◽  
Chest Radiographs ◽  
Rt Pcr ◽  
Female Age ◽  
Emergency Radiologist ◽  
Polymerase Chain ◽  
Time Of Presentation ◽  
Label Distribution

Background Chest radiographs (CXR) are frequently used as a screening tool for patients with suspected COVID-19 infection pending reverse transcriptase polymerase chain reaction (RT-PCR) results, despite recommendations against this. We evaluated radiologist performance for COVID 19 diagnosis on CXR at the time of patient presentation in the Emergency Department (ED). Materials and Methods We extracted RT PCR results, clinical history, and CXRs of all patients from a single institution between March and June 2020. 984 RT PCR positive and 1043 RT-PCR negative radiographs were reviewed by 10 emergency radiologists from 4 academic centers. 100 cases were read by all radiologists and 1927 cases by 2 radiologists. Each radiologist chose the single best label per case: Normal, COVID 19, Other Infectious, Other Noninfectious, Non diagnostic, and Endotracheal Tube. Cases labeled with endotracheal tube or non-diagnostic were excluded. Remaining cases were analyzed for label distribution, clinical history, and inter-reader agreement. Results 1727 radiographs (732 RT PCR positive, 995 RT PCR negative) were included from 1,594 patients (51.2% male, 48.8% female, age 59 +/- 19 years). For 89 cases read by all readers, there was poor agreement for RT PCR positive (Fleiss Score 0.36) and negative (Fleiss Score 0.46) exams. Agreement between two readers on 1,638 cases was 54.2% (373/688) for RT-PCR positive cases and 71.4% (679/950) for negative cases. Agreement was highest for RT PCR negative cases labeled as Normal (50.4%, n= 479). Reader performance did not improve with clinical history or time between CXR and RT-PCR result. Conclusion At the time of presentation to the emergency department, emergency radiologist performance is non-specific for diagnosing COVID 19.

scholarly journals Nowcast Deep Learning Models For Constraining Zero-Day Pathogen Attacks – Application on Chest Radiographs to Covid-19

2020 ◽  
Author(s):  
Michael D. Kuo ◽  
Wan Hang Keith Chiu ◽  
Varut Vardhanabhuti ◽  
Dymtro Poplavskiy ◽  
Philip LH Yu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Sensitivity And Specificity ◽  
Detection System ◽  
Chest Radiographs ◽  
Sufficient Information ◽  
Operating Characteristics ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Prospective Cohorts ◽  
Polymerase Chain

Abstract Outbreaks due to emergent pathogens like Covid-19 are difficult to contain as the time to gather sufficient information to develop a detection system is outpaced by the speed of transmission. Here we develop a general pneumonia (PNA) CXR Deep Learning (DL) model (MAIL1.0) follow by a second-generation DL model (MAIL2.0) for detection of Covid-19 on chest radiographs (CXR). We validate the models on two prospective cohorts of high-risks patients screened for Covid-19 reverse transcriptase-polymerase chain reaction (RT-PCR). MAIL1.0 has an Area Under the Receiver Operating Characteristics (AUC) of 0.93, sensitivity and specificity of 90.5% and 76.7% in detection of visible pneumonia and MAIL2.0 has an AUC of 0.81, sensitivity and specificity of 84.7% and 71.6%, significantly outperforming radiologists, especially amongst asymptomatic and patients presenting with early symptoms. Nowcast DL models may be an effective tool in helping to constrain the outbreak, particularly in resource-stretched healthcare systems.

scholarly journals Brugada-like ECG Pattern in COVID-19 Infection

2020 ◽  
Author(s):  
Amir Tavoosi ◽  
Mehrangiz Zangeneh ◽  
Mansoor Mohsen Abadi ◽  
Mahin Nomali ◽  
Kian Alipasandi
Keyword(s):  
Hospital Stay ◽  
Troponin I ◽  
Transient Condition ◽  
Type I ◽  
Rt Pcr ◽  
Normal Range ◽  
History Of ◽  
Polymerase Chain ◽  
Time Of Presentation ◽  
Electrocardiogram Ecg

The Brugada-like ECG pattern is a transient condition which may be induced by number of conditions. In this case reported, a 53-year-old Iranian male patient, presented with 7-day history of fever, chills, headache and shortness of breath. At the time of presentation to the Emergency Department (ED), the patient was febrile with tachycardia, tachypnea, and oxygen (O2) saturation 75%. The chest radiograph showed a bilateral infiltration and positive result of Real Time Polymerase Chain Reaction (RT-PCR) confirmed the diagnosis of COVID-19 infection. He received Kaletra, Hydroxychloroquine, Azithromycin, Antibiotics, and Intravenous Immunoglobulin (IVIG). The patients was intubated and underwent mechanical ventilation because of no improvement on the O2 saturation level. Fever subsided on 7th day and Hydroxychloroquine was stopped on 5th day. On the sixth day of hospital stay, Electrocardiogram (ECG) showed sinus tachycardia. Troponin-I- high sensitive was within normal range and Transthoracic Echocardiography (TTE) showed normal Ejection Fraction (EF). On 10th day, type I Brugada ECG pattern presented and regular ECG monitoring was recommended. Finally, after eleven-day hospital stay, the patient died due to bradycardia and asystole despite Cardiopulmonary Resuscitation (CPR). Thus, physicians should consider Brugada ECG pattern in the precordial leads (V1 to V3) of ECG among patients with COVID-19 infection beside regular QT interval monitoring.

scholarly journals Emergency calls are early indicators of ICU bed requirement during the COVID-19 epidemic

2020 ◽  
Author(s):  
◽  
Bruno Riou
Keyword(s):  
Intensive Care Unit ◽  
Emergency Department ◽  
Intensive Care ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Icu Patients ◽  
Ambulance Dispatch ◽  
Polymerase Chain ◽  
Gp Visits ◽  
Second Wave

AbstractBackgroundAlthough the number of intensive care unit (ICU) beds is crucial during the COVID-19 epidemic caring for the most critically ill infected patients, there is no recognized early indicator to anticipate ICU bed requirements.MethodsIn the Ile-de-France region, from February 20 to May 5, 2020, emergency medical service (EMS) calls and the response provided (ambulances) together the percentage of positive reverse transcriptase polymerase chain reaction (RT-PCR) tests, general practitioner (GP) and emergency department (ED) visits, and hospital admissions of COVID-19 patients were recorded daily and compared to the number of COVID-19 ICU patients. Correlation curve analysis was performed to determine the best correlation coefficient (R), depending on the number of days the indicator has been shifted. A delay ≥7 days was considered as an early alert, and a delay ≥14 days a very early alert.FindingsEMS calls, percentage of positive RT-PCR tests, ambulances used, ED and GP visits of COVID-19 patients were strongly associated with COVID-19 ICU patients with an anticipation delay of 23, 15, 14, 13, and 12 days respectively. Hospitalization did not anticipate ICU bed requirement.InterpretationThe daily number of COVID19-related telephone calls received by the EMS and corresponding dispatch ambulances, and the proportion of positive RT-PCR tests were the earliest indicators of the number of COVID19 patients requiring ICU care during the epidemic crisis in the Ile-de-France region, rapidly followed by ED and GP visits. This information may help health authorities to anticipate a future epidemic, including a second wave of COVID19 or decide additional social measures.FundingOnly institutional funding was provided.Research in contextEvidence before the studyWe searched PubMed and preprint archives for articles published up to May 17, 2020, that contained information about the anticipation of intensive care unit (ICU) bed requirement during the COVID-19 outbreak using the terms “coronavirus”, “2009-nCOV”, “COVID-19”, SARS-CoV2”, “prediction” “resource” and “intensive care”. We also reviewed relevant references in retrieved articles and the publicly available publication list of the COVID-19 living systematic review.22 This list contains studies on covid-19 published on PubMed and Embase through Ovid, bioRxiv, and medRxiv, and is continuously updated. Although many studies estimated the number of patients who would have severe COVID-19 requiring ICU, very few contained assessment for early signals (from internet or social media), and we retrieved no study whose data came from suspected or infected patients.Added values of this studyDuring the COVID-19 epidemic, emergency medical system (EMS) calls, percentage of positive reverse transcriptase polymerase chain reaction (RT-PCR) tests, ambulance dispatch, emergency department (ED) and general practitioner (GP) visits of COVID-19 patients were strongly associated with COVID-19 ICU patients with an anticipation delay of 23, 15, 14, 13, and 12 days respectively. Hospitalization did not anticipated COVID-19 ICU bed requirement.Implication of all available evidenceEMS calls and ambulance dispatch, percent of positive RT-PCR, and ED and GP visits could be valuable tools as daily alert signals to set up plan to face the burden of ICU bed requirement during the initial wave of the COVID-19 epidemic, and may possibly also help anticipating a second wave. These results are important since mortality has been reported being correlated to health care resources.

scholarly journals Rapid Antigen Test Combined with Chest Computed Tomography to Rule Out COVID-19 in Patients Admitted to the Emergency Department

2021 ◽  
Vol 10 (16) ◽  
pp. 3455
Author(s):  
Sabrina Kepka ◽  
Mickaël Ohana ◽  
François Séverac ◽  
Joris Muller ◽  
Eric Bayle ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Emergency Department ◽  
Real Life ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Chest Computed Tomography ◽  
Polymerase Chain ◽  
Medical Wards ◽  
Combined Strategy ◽  
Rule Out

Objective: Correct and timely identification of SARS-CoV-2-positive patients is critical in the emergency department (ED) prior to admission to medical wards. Antigen-detecting rapid diagnostic tests (Ag-RDTs) are a rapid alternative to Reverse-transcriptase polymerase chain reaction (RT-PCR) for the diagnosis of COVID-19 but have lower sensitivity. Methods: We evaluated the performance in real-life conditions of a strategy combining Ag-RDT and chest computed tomography (CT) to rule out COVID-19 infection in 1015 patients presenting in the ED between 16 November 2020 and 18 January 2021 in order to allow non-COVID-19 patients to be hospitalized in dedicated units directly. The combined strategy performed in the ED for patients with COVID-19 symptoms was assessed and compared with RT-PCR. Results: Compared with RT-PCR, the negative predictive value was 96.7% for Ag-RDT alone, 98.5% for Ag-RDT/CT combined, and increased to 100% for patients with low viral load. Conclusion: A strategy combining Ag-RDT and chest CT is effective in ruling out COVID-19 in ED patients with high precision.

scholarly journals Incidence of Sars-COV-2 Infection in Sickle Cell Patients Presenting with a Painful Crisis, a 12 Month Prospective Cohort Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 969-969
Author(s):  
Kadère Konté ◽  
Erfan Nur ◽  
Man Wai Tang ◽  
Jarom Heijmans ◽  
Charlotte F.J. Van Tuijn ◽  
...  
Keyword(s):  
Emergency Department ◽  
Sickle Cell ◽  
Respiratory Symptoms ◽  
Upper Airway ◽  
Ct Scans ◽  
Acute Chest Syndrome ◽  
Rt Pcr ◽  
High Incidence ◽  
Polymerase Chain ◽  
Low Incidence

Abstract Background: Sickle cell disease (SCD) is frequently complicated by painful vaso-occlusive crises (VOCs) often resulting in healthcare utilization including hospital admission. A vaso-occlusive crisis (VOC) can be induced by multiple factors including infection, exposure to cold, physical exercise, dehydration and stress. Given the current SARS-CoV-2 pandemic, we hypothesized that SARS-CoV-2 (even without symptoms of upper airway infection) might play a major causal role in VOC. However, our data suggests that COVID-19 is not a frequent provoking factor for clinical VOCs during the pandemic. Methods: In order to test this hypothesis, consecutive SCD patients presenting to the emergency department in our centre with symptoms compatible with VOC between March 16 th 2020 and March 16 th 2021, were tested for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) of nasopharyngeal swabs irrespective of respiratory symptoms. Given the limited sensitivity of the RT-PCR in SARS-CoV-2 high incidence groups, low-dose non-contrast chest CT-scans were initially performed in addition to the RT-PCR.In addition, data comprised of temperature, oxygen saturation and laboratory results, was collected through chart review, from the visit at the emergency department. Presentations of SCD patients with a proven prior SARS-CoV-2 infection were excluded. Results: In total 122 VOCs in 70 adult SCD patients, presenting to the emergency department between March 16 th 2020 and March 16 th 2021, were evaluated. (Figure 1) Five presentations in two individual patients were excluded due to a prior RT-PCR proven SARS-CoV-2 infection. Furthermore, 13 presentations in six patients were excluded due to non-protocol adherence (not obtaining a RT-PCR at presentation). In total 104 episodes of VOC in 62 patients with SCD were prospectively analyzed on SARS-CoV-2 by RT-PCR irrespective of respiratory symptoms. In 104 consecutive presentations, five presentations tested positive on SARS-CoV-2 (4.8%). Only one of these five patients presented with respiratory symptoms in addition to the symptoms of a VOC and one patient was diagnosed with acute chest syndrome (ACS). Five of the 99 presentations of patients with a negative SARS-CoV-2 PCR, presented with respiratory symptoms. In this group, seven patients developed an ACS during admission. From March 16 th till May 31 st 2020, routine CT-scans were performed, in 23 out of 27 presentations with a VOC at the emergency department in addition to the RT-PCR in order to increase the diagnostic accuracy. In 19 of these presentations, that were tested negative for SARS-COV-2, no CT-abnormalities suggestive for COVID-19 were found. One of four CT-scans performed in patients with a positive RT-PCR, showed abnormalities that were not specific for COVID-19. Conclusion: In conclusion, we found a low incidence of SARS-CoV-2 infections in our cohort of consecutive SCD patients presenting with VOCs in 12 months during the COVID-19 pandemic. This suggests that COVID-19 is not a frequent provoking factor for clinical VOCs during the pandemic and may even be considered a coincidental finding given the low incidence and the fact that only one of the five patients with a positive RT-PCR presented with pulmonary symptoms. Figure 1 Figure 1. Disclosures Nur: Celgene: Speakers Bureau; Roche: Speakers Bureau; Novartis: Research Funding, Speakers Bureau.

1504: Molecular Diagnosis and Staging of Prostate Cancer Using Clusterin in Real Time Reverse Transcription Polymerase Chain Reaction (RT-PCR)

2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske
Keyword(s):  
Prostate Cancer ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Molecular Diagnosis ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

Cloning of the cDNA Encoding Human Platelet CD36: Comparison to PCR Amplified Fragments of Monocyte, Endothelial and HEL Cells

1993 ◽  
Vol 70 (03) ◽  
pp. 500-505 ◽  
Author(s):  
B Wyler ◽  
L Daviet ◽  
H Bortkiewicz ◽  
J-C Bordet ◽  
J L McGregor
Keyword(s):  
Apparent Molecular Weight ◽  
Platelet Glycoprotein ◽  
Rt Pcr ◽  
Post Translational Modifications ◽  
Hel Cells ◽  
Flanking Region ◽  
Polymerase Chain ◽  
A Minor ◽  
Flanking Regions ◽  
Cdna Fragments

SummaryGlycoprotein CD36, also known as GPIIIb or GPIV, is a major platelet glycoprotein that bears the newly identified Naka alloantigen. The aim of this study was to clone platelet CD36 and investigate other forms of CD36-cDNA present in monocytes, endothelial and HEL cells. RNA from above mentioned cells were reverse transcribed (RT), using specific primers for CD36, and amplified by the polymerase chain reaction (PCR) technique. Sequencing the different amplified platelet derived cDNA fragments, spanning the whole coding and flanking regions, showed the near identity between platelet and CD36-placenta cDNA. Platelet CD36-cDNA cross-hybridized, in Southern blots, with RT-PCR amplified cDNA originating from monocytes, endothelial and HEL cells. However, monocytes showed a RT-PCR amplified cDNA fragment (561 bp) that was present in platelets and placenta but not on endothelial on HEL-cells. Northern blot analysis of platelet RNA hybridized with placenta CD36 indicated the presence of a major (1.95 kb) and a minor (0.95 kb) transcript. The 1.95 kb transcript was the only one observed on Northern blots of monocytes, endothelial and HEL cells. These results indicate that the structure of CD36 expressed in platelets is similar, with the exception of the 3’ flanking region, to that of placenta. Differences in apparent molecular weight between CD36 and CD36-like glycoproteins may be due to post-translational modifications.

Expression of Platelet Membrane Glycoprotein V in Human Megakaryocytes and Megakaryocytic Cell Lines: A Study Using a Novel Monoclonal Antibody against GPV

1994 ◽  
Vol 72 (05) ◽  
pp. 762-769 ◽  
Author(s):  
Toshiro Takafuta ◽  
Kingo Fujirmura ◽  
Hironori Kawano ◽  
Masaaki Noda ◽  
Tetsuro Fujimoto ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Lines ◽  
Immunohistochemical Analysis ◽  
Specific Protein ◽  
Platelet Membrane ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Flow Cytometric ◽  
Polymerase Chain ◽  
Megakaryocytic Cell

SummaryGlycoprotein V (GPV) is a platelet membrane protein with a molecular weight of 82 kD, and one of the leucine rich glycoproteins (LRG). By reverse transcription-polymerase chain reaction (RT-PCR), GPV cDNA was amplified from mRNA of platelets and megakaryocytic cell lines. However, since there are few reports indicating whether GPV protein is expressed in megakaryocytes as a lineage and maturation specific protein, we studied the GPV expression at the protein level by using a novel monoclonal antibody (1D9) recognizing GPV. Flow cytometric and immunohistochemical analysis indicated that GPV was detected on the surface and in the cytoplasm of only the megakaryocytes in bone marrow aspirates. In a megakaryocytic cell line UT-7, GPV antigen increased after treatment with phorbol-12-myri-state-13-acetate (PMA). These data indicate that only megakaryocytes specifically express the GPV protein among hematopoietic cells and that the expression of GPV increases with differentiation of the megakaryocyte as GPIb-IX complex.

Polymerase chain reaction amplification and typing of rotavirus in environmental samples

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch
Keyword(s):  
Polymerase Chain Reaction ◽  
Environmental Samples ◽  
Polymerase Chain Reaction Amplification ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Group A ◽  
Reaction Amplification ◽  
Stool Specimens ◽  
Polymerase Chain

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.

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