COVID-19 Pneumonia Patients Research Articles

The Role of Lung Ultrasound Monitoring in Early Detection of Ventilator-Associated Pneumonia in COVID-19 Patients: A Retrospective Observational Study.

Specific lung ultrasound signs combined with clinical parameters allow for early diagnosis of ventilator-associated pneumonia in the general ICU population. This retrospective cohort study aimed to determine the accuracy of lung ultrasound monitoring for ventilator-associated pneumonia diagnosis in COVID-19 patients. Clinical (i.e., clinical pulmonary infection score) and ultrasound (i.e., presence of consolidation and a dynamic linear–arborescent air bronchogram, lung ultrasound score, ventilator-associated lung ultrasound score) data were collected on the day of the microbiological sample (pneumonia-day) and 48 h before (baseline) on 55 bronchoalveolar lavages of 33 mechanically-ventilated COVID-19 patients who were monitored daily with lung ultrasounds. A total of 26 samples in 23 patients were positive for ventilator-associated pneumonia (pneumonia cases). The onset of a dynamic linear–arborescent air bronchogram was 100% specific for ventilator-associated pneumonia. The ventilator-associated lung ultrasound score was higher in pneumonia-cases (2.5 (IQR 1.0 to 4.0) vs. 1.0 (IQR 1.0 to 1.0); p < 0.001); the lung ultrasound score increased from baseline in pneumonia-cases only (3.5 (IQR 2.0 to 6.0) vs. −1.0 (IQR −2.0 to 1.0); p = 0.0001). The area under the curve for clinical parameters, ventilator-associated pneumonia lung ultrasound score, and lung ultrasound score variations were 0.472, 0.716, and 0.800, respectively. A newly appeared dynamic linear–arborescent air bronchogram is highly specific for ventilator-associated pneumonia in COVID-19 patients. A high ventilator-associated pneumonia lung ultrasound score (or an increase in the lung ultrasound score) orients to ventilator-associated pneumonia.

Leveraging digital technologies for information technology-enabled healthcare transformation at SingHealth

Singapore Health Services, or SingHealth in short, is Singapore’s largest public health organisation. SingHealth was established in the year 2000 with ‘the aim to deliver consistently high-quality care that is appropriate and accessible to patients’. Since its inception, SingHealth has introduced numerous digital innovations to strengthen its business model and healthcare delivery. These include investments in mobile applications such as HealthBuddy and MyCare, which are widely used by patients in Singapore to manage their medical appointments, order their medication and monitor their health, which can all be done remotely. With the Covid-19 pandemic, SingHealth introduced Swabot which helped carry out automated nasal swabs at Covid-19 testing sites; Doctor Covid, which is a chatbot hosted on Telegram, an online messaging application that helps to improve care for Covid-19 patients in community care settings; and an AI-based tool called the Community-Acquired Pneumonia and Covid-19 AI Predictive Engine, which can determine the severity of pneumonia in Covid-19 patients based on chest x-ray images. SingHealth’s investments in information systems and technologies have enabled SingHealth to improve its operations, provide better healthcare delivery to patients, better manage doctors’ and nurses’ workload, and address the various challenges posed by the Covid-19 pandemic. This case examines how digital technologies revolutionised SingHealth’s workflows and processes, resulting in better quality healthcare for patients, and will be helpful for healthcare organisations looking to leverage on technology and health informatics for optimum healthcare delivery.

A little education goes a long way: Decreasing antibiotics for community-acquired pneumonia in COVID-19 patients

Background: Antibiotic use was common in patients with suspected or confirmed COVID-19 infection; however, data emerged demonstrating low rates of bacterial coinfection (6%–10%). Antimicrobial stewardship best practice was challenged during this time, requiring new strategies and education to limit the inappropriate use of antibiotics. At the Veterans’ Affairs Maryland Healthcare System, we evaluated the use of community acquired pneumonia (CAP) specific antibiotics in COVID-19–positive patients after successive interventions. Methods: We conducted a pre–post evaluation of common CAP antibiotics (ceftriaxone IV/IM, cefpodoxime PO, azithromycin PO/IV, ampicillin/sulbactam IV, amoxicillin-clavulanate PO, levofloxacin) during the COVID-19 pandemic. The preintervention period was April–October 2020 and the postintervention period was November 2020–April 2021. During the preintervention period, intervention A was carried out as follows: (1) inpatient weekly virtual interdisciplinary COVID-19 rounds were led by an antimicrobial stewardship champion, (2) χprocalcitonin was implemented in clinical decision making, and (3) inpatient audit and feedback of active antibiotics was conducted by the antimicrobial stewardship team. In the postintervention period, intervention B was added as follows: (1) weekly educational COVID-19 virtual seminars were conducted for providers, and (2) targeted education was provided to emergency department and hospitalist directors. Comparisons of the proportions of antibiotics prescribed were made between the pre- and postintervention periods using X2 statistic, and data were stratified by location. The rates of CAP antibiotic prescription per 100 COVID-19–positive patients were also compared using Poisson distribution. Results: During the study period, 814 unique patients had COVID-19 infection: 182 (22.4%) patients admitted to the acute-care center, 66 (8.1%) long-term care residents, and 566 (69.5%) were managed outside the hospital. Of these 814 patients, 211 (25%) were prescribed a CAP antibiotic. Of the antibiotics prescribed, 223 (61%) were ceftriaxone, cefpodoxime, amoxicillin-clavulanate, or ampicillin-sulbactam; 123 (34%) were azithromycin; and 16 (4.4%) were levofloxacin. We observed a decrease in the frequency of all antibiotic prescriptions after intervention B was added: 32% (86 of 273) vs 23% (125 of 541) (P = .01). Decreases in antibiotic prescriptions were observed in all locations: acute care (57% vs 44%), long-term care (53% vs 41%) and outpatient care (19% vs 15%). The rates of CAP antibiotic prescribing per 100 COVID-19–positive patients were 114 in the preintervention period and 45 in the postintervention period, a rate difference of −70 antibiotics per 100 COVID-19–positive patients (pConclusions: Curbing antibiotic use for CAP indication during the COVID-19 pandemic was a challenge. A multifaceted approach focusing on education was an impactful intervention leading to significant decreases in antibiotic prescribing despite COVID-19 cases increasing.Funding: NoneDisclosures: None

Can Lung Imaging Scores and Clinical Variables Predict Severe Course and Fatal Outcome in COVID-19 Pneumonia Patients? A Single-Center Observational Study.

COVID-19 prediction models mostly consist of combined clinical features, laboratory parameters, and, less often, chest X-ray (CXR) findings. Our main goal was to propose a prediction model involving imaging methods, specifically ultrasound. This was a single-center, retrospective cohort observational study of patients admitted to the University Hospital Split from November 2020 to May 2021. Imaging protocols were based on the assessment of 14 lung zones for both lung ultrasound (LUS) and computed tomography (CT), correlated to a CXR score assessing 6 lung zones. Prediction models for the necessity of mechanical ventilation (MV) or a lethal outcome were developed by combining imaging, biometric, and biochemical parameters. A total of 255 patients with COVID-19 pneumonia were included in the study. Four independent predictors were added to the regression model for the necessity of MV: LUS score, day of the illness, leukocyte count, and cardiovascular disease (χ2 = 29.16, p < 0.001). The model accurately classified 89.9% of cases. For the lethal outcome, only two independent predictors contributed to the regression model: LUS score and patient’s age (χ2 = 48.56, p < 0.001, 93.2% correctly classified). The predictive model identified four key parameters at patient admission which could predict an adverse outcome.

Time-Dependent Increase in Susceptibility and Severity of Secondary Bacterial Infections During SARS-CoV-2.

Secondary bacterial infections can exacerbate SARS-CoV-2 infection, but their prevalence and impact remain poorly understood. Here, we established that a mild to moderate infection with the SARS-CoV-2 USA-WA1/2020 strain increased the risk of pneumococcal (type 2 strain D39) coinfection in a time-dependent, but sex-independent, manner in the transgenic K18-hACE2 mouse model of COVID-19. Bacterial coinfection increased lethality when the bacteria was initiated at 5 or 7 d post-virus infection (pvi) but not at 3 d pvi. Bacterial outgrowth was accompanied by neutrophilia in the groups coinfected at 7 d pvi and reductions in B cells, T cells, IL-6, IL-15, IL-18, and LIF were present in groups coinfected at 5 d pvi. However, viral burden, lung pathology, cytokines, chemokines, and immune cell activation were largely unchanged after bacterial coinfection. Examining surviving animals more than a week after infection resolution suggested that immune cell activation remained high and was exacerbated in the lungs of coinfected animals compared with SARS-CoV-2 infection alone. These data suggest that SARS-CoV-2 increases susceptibility and pathogenicity to bacterial coinfection, and further studies are needed to understand and combat disease associated with bacterial pneumonia in COVID-19 patients.

The 6-Minute Walk Test: Indications and Guidelines for Use in Outpatient Practices

The 6-Minute Walk Test (6MWT) is a standardized tool used to measure lung impairment. It is used in outpatient primary and pulmonary practices to objectively assess functional exercise capacity and hypoxemia in patients with chronic lung disease. Screening for functional decrease in exercise tolerance and hypoxemia aids in initiating and maintaining the use of oxygen supplementation to improve functional improvement in chronic lung patients. It has new applications for recovering COVID-19 pneumonia patients to assess for clinical compromise. Discussion includes elements and guideline recommendations for 6MWT, indications for use, appropriate patient populations appropriate, safety, coding, and current reimbursement insurance guidelines.

COVID-19 pneumonia patients with 25(OH)D levels lower than 12 ng/ml are at increased risk of death

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Sudden cardiac death in a case of Crohn's disease with COVID-19

Rationale: The mechanism of sudden cardiac death in COVID-19 can be multifactorial. Cardiac hypersensitivity to 5-ASA therapy leading to myocarditis has been reported in some cases. Cytokine storm syndrome and idiosyncratic reaction with mesalazine use may lead to sudden cardiac death in COVID-19. Use of immunosuppressants in hospitalized COVID-19 patients should be continued with caution, especially in patients with inflammatory bowel disease. Patient's concern: A 75-year-old man who was tested positive for SARS-CoV-2 was admitted with a history of shortness of breath for the last two days. He was a known case of Crohn's disease treated with mesalazine. Diagnosis: COVID-19 pneumonia with underlying Crohn's disease leading to sudden cardiac death. Intervention: Remdesivir, antibiotics, steroids, low molecular weight heparin, tablet zinc, tab vitamin C, and other supportive treatment were started. Because of increased inflammatory markers, itolizumab was given to the patient on the 2nd day. Outcome: On the 5th day of the intensive care unit, the patient complained of sudden chest pain with respiratory distress leading to bradycardia and asystole and could not be resuscitated. Lessons: Causes for sudden cardiac death in COVID-19 pneumonia patients with Crohn's disease is multifactorial. Although mesalazine may be a safe and effective drug in the management of inflammatory bowel disease, it can induce sytokine strom syndrome and idiosyncratic reactions that could be one of the reasons of sudden cardic death. Therefore, we should be aware of its serious and potentially life-threatening complications, especially in COVID-19 infected patients.

Endobronchial valve use in COVID-19 related pneumothorax and persistent air leak.

Pneumothoraces may occur rarely in coronavirus (COVID-19) patients, often resulting from a combination of fibrotic parenchymal changes and prolonged high-pressure ventilation. Very few studies have been published describing the management of pneumothorax in the novel COVID-19 pneumonia patients. Although chest drain insertion represents the first line of treatment, a persistent pneumothorax and air leak requiring intervention could be managed by a thoracoscopic procedure or, as is the case here, by endobronchial valve insertion. Endobronchial valve insertion is a minimally invasive technique that provides a treatment option in patients with severe parenchymal COVID-19 related lung disease. As far as the authors are aware this is the first report of the use of endobronchial valves in a COVID-19 patient.

Type-H, and Type-L COVID-19: are they different subtypes or the same?

SARS-CoV-2 infection, which causes severe pneumonia, caused an epidemic that started in Wuhan, China in December 2019 and spread to the whole world. COVID-19 mainly affects the respiratory system and causes the development of severe pneumonia and related acute respiratory distress syndrome (ARDS) in some patients. We aimed to investigate whether COVID-19 pneumonia cases can be evaluated in different categories in clinical and radiological terms. COVID-19 associated ARDS cases being treated with the diagnosis of severe pneumonia between March 21, 2020 and June 15, 2020 in Anesthesia Intensive Care Unit were examined and divided into 2 groups (type-L and type-H, total 29 cases) according to their clinical findings (according to whether they benefited from high PEEP and their lung compliance) and lung computed tomography findings (according to the severity of the ground glass appearance). The groups were compared with each other in terms of inflammatory markers [CRP (C reactive protein), ferritin, D Dimer, PCT (procalcitonin), white blood cell, lymphocyte count, arterial blood gas analysis] and imaging findings. It was observed that the prone position was beneficial in improving oxygenation in both H-type and L-type patients. 7 of 22 L-type patients were intubated and 5 of these patients died. There was no statistical difference between the two groups in terms of intubation times, hospital stays, cytokine levels, prone position application responses and mortality rates. Are there two separate forms of COVID-19 pneumonia, such as h-type and l-type, or are they intertwined and describe the early and late stages of the disease? This question needs to be discussed. In addition, we believe that subtyping COVID-19 pneumonia patients does not make a difference in the treatments to be applied.

COVID 19 AND SPONTANEOUS PNEUMOTHORAX, RETROSPECTIVE CASE SERIES

COVID-19 Sars Co V2 or Corona Virus disease is a highly infectious multisystem disease with severe acute lung injury leading to ARDS and respiratory failure as its main complication. Spontaneous pneumothorax is a complication which is though uncommon but could be life threatening and hence carries poor prognosis. We hereby describe a series of six cases of spontaneous pneumothorax which were seen in Bahria International Hospital COVID management unit during last 3 months of COVID-19 surge in Lahore These cases indicate that multiple factors are associated with development of spontaneous pneumothorax in COVID-19 pneumonia patients but main role is played by the increased inflammatory response and can be regarded as a potential underlying mechanism of pneumothorax in such patients, leading to acute decompensation and worsening of respiratory failure and poor outcome.

Tentamen Suicide in Neuropsychiatric Syndrome in Severe COVID-19 Intensive Care Patient with Respiratory Failure: a Serial Cases

Abstract&#x0D; Introduction : COVID-19 is a pneumonia caused by SARS-CoV-2 infection, that can cause morbidity and mortality in the care of critical patients in the Covid-specific Intensive Care Unit (RICU). Tentamen suicide is one of severe neuro-psychiatric syndrome which can aggravate the condition of patients with acute respiratory failure. Methode : We present 3 cases of patients with suicide trial in severe COVID-19 Pneumonia accompanied by acute respiratory failure. Results : Patients with tentamen suicide experience a gradual worsening of condition. This complication especially tentamen suicide is not well recognized at the beginning of treatment. Conclusion :The conclusion of this case series is tentamen suicide is one of severe neuropsychiatric syndrome in COVID-19 patient with respiratory failure. Early recognizing and conducting clinical management of neuropsychiatric syndrome symptoms in COVID-19 Pneumonia patients with acute respiratory failure who are intensively treated at the RICU can reduce the risk of morbidity, mortality and improve patient outcomes.&#x0D;

Assessment of therapeutic response of the Tocilizumab in SARS-CoV-2 associated cytokine storm: A single center experience

Background: Critical COVID-19 patients may present with a cytokine storm-like phenomenon. IL-6 is found to be a key player in this cytokine storm, and COVID-19 severity is directly linked to the IL-6 levels. Objective: To assess the response of Tocilizumab during the inflammatory phase of COVID-19 patients. Methodology: This cross-sectional study was based on a retrospective collection of data from the records of a total of 17 COVID patients, admitted to the COVID Unit of Farooq Hospital, Lahore, from 1st October 2020 to 30th December 2020. The ethical review board of Akhtar Saeed Medical and Dental College, Lahore approved the research. All these patients received 8mg/kg of body weight Tocilizumab intravenously for pneumonia in COVID-19 patients. All these patients were evaluated for IL-6 levels in serum initially for 2-3 days (24-48 hours) before and after the 3rd day and 7th day of Tocilizumab infusion. The Electrochemiluminescence immunoassay method was used to quantify serum IL-6. The SPSS (v. 22.0) was used for analysis. Results: The analysis shows that the median (IQR) IL-6 levels prior to treatment with Actemra, three days after Actemra administration, and seven days after Actemra was administered, were 1879 (IQR=726-2842), 1136 (IQR=499-2266), and 438 (IQR=151-1085), respectively. The change in Il-6 levels before and after Actemra administration was statistically significant, (p=0.001). A notable difference was also observed between IL-6 levels with respect to Actemra administration after three and seven days (p=0.04). There was a statistically significant median difference in IL-6 levels seven days post-Actemra in patients who survived and died, (P=0.01). Conclusion: Tocilizumab administration along with sequential laboratory investigations particularly IL6 might be helpful in reducing the complications of cytokine storm in patients with severe COVID-19 pneumonia, resulting in better outcomes.

IMPACT OF POST COVID PULMONARY SEQUELAE IN DECIDING RADIOLOGICAL OUTCOME: AN OBSERVATIONAL STUDY

Background: A number of patients with COVID-19 pneumonia were discharged from hospitals in central India.This study highlights the relevant affecting factors, and to describe the chest CT ndings and sequelae during follow up. Aims And Objectives: our aim was to determine the cumulative percentage of complete radiological resolution at the time of active disease and at follow up after discharge ,highlight the predominant ndings in follow-up post covid CT and to correlate CTSS and the type of lung parenchymal opacity with chances of radiological resolution. Methods: Patients with COVID-19 pneumonia conrmed by RT-PCR who were discharged consecutively from the hospital between September 2020 and November 2020 and who underwent serial chest CT scans on their visit to post COVID OPD were enrolled in a retrospective observational study. The radiological characteristics of all patients were collected, analyzed and the total CT score was calculated. Imaging features and distributions were analyzed across different time points. Results: A total of 385 patients were evaluated; there were 286 (74.2%) men and 99 (28.7%) women, with a median age of 43 years old (IQR 36–56). Complete radiological resolution was seen in 74(19%) patients on follow up CT, while 49(12.7%) patients showed normal chest CT during active disease. Patients ≤40 years old showed a slightly higher cumulative percentage of complete radiological resolution than patients &gt; 40 years old at the follow-up CT. The predominant patterns of abnormalities observed during the active disease were ground-glass opacity (GGO) (321 [83.3%]), consolidation (283 [73.5%]), and subpleural atelectatic brotic bands (235 [61%]). While on follow up scan, the positive count of GGO and consolidations gradually decreased, few brotic bands remained in almost all 235 patients who showed brotic changes earlier. Conclusion: Most of the lung lesions in COVID-19 pneumonia patients can be absorbed completely during short-term followup with sequelae of subcentimetric pleural atelectatic brotic bands only. The optimal time point for early radiological estimation might be three to four weeks after discharge.

Experience in the use of lung ultrasound in patients of the respiratory hospital of Siberian State Medical University with COVID-19 pneumonia

Aim. To evaluate the possibility of using lung ultrasound for diagnosing COVID-19 pneumonia in patients of the respiratory hospital of Siberian State Medical University (SSMU).Materials and methods. An analysis of lung ultrasound data was carried out in 39 patients (17 men and 22 women aged 33–78 years) with COVID-19 pneumonia. Lung ultrasound was performed in all patients in addition to radiography performed at the prehospital stage and in 15 patients who underwent computed tomography (CT) of the lungs.Results. In the majority (61.6%) of cases, during the ultrasound examination, COVID-19 pneumonia manifested itself as interstitial lung disease. The white lung phenomenon and a combination of the aforementioned interstitial changes were recorded with the same frequency (5.1%), while pulmonary consolidation in addition to interstitial changes was visualized in 10.2% of cases. Interstitial lung disease was bilateral in 83.3% of patients and unilateral in 16.7% of cases. The inferior lobes of the lungs were affected in 60.0% of cases, middle lobe – in 30.0% of cases, and superior lobes – in 15.0% of patients. The ultrasound examination detected changes in the lungs in 32 patients, while radiographic changes were present in 35 cases. Bilateral inflammation was more often detected by radiography than by ultrasound. When comparing the data of lung ultrasound and CT, the agreement between the methods was found in 66.7% of cases, and the discrepancy between the findings of the two methods was observed mainly in patients with a large number of affected segments of the lungs and localization of the disease in the superior lobes according to CT.Conclusion. Lung ultrasound is a valuable tool that can be used to stratify risk in patients at any stage of diagnosis and treatment in the context of the COVID-19 pandemic due to availability, speed of implementation, and the absence of a need for patient transportation.

Evaluation of the Difference Between non-COVID-19 Pneumonia and COVID-19 Pneumonia Nursing Care

Aim This study was aimed to contribute to the nursing care of COVID-19 pneumonia by determining the similarities and differences in nursing care for COVID-19 pneumonia and non-COVID-19 pneumonia. Methods This study aimed to retrospectively evaluate the nursing care applied to 84 pneumonia patients who were hospitalized in Sivas Numune Hospital Chest Diseases Service between 2018-2019 and 81 in patients with COVID-19 pneumonia between May and November 2020. Results COVID-19 pneumonia patients were older than non-COVID-19 pneumonia patients (p&lt;0.001), and the majority of patients were hypertensive and diabetic (p&lt;0.05). The most common symptom for COVID-19 pneumonia patients is dyspnea (p&lt;0.05) while for non-COVID-19 pneumonia patients it is fever (p&lt;0.001). 77.8% of COVID-19 pneumonia patients but non-COVID-19 pneumonia patients had bilateral pneumonia with the feature of multiple mottling and ground-glass opacity on CT images. LDH, CRP, PCT, AST/ALT, and D-dimer levels increased significantly higher in COVID-19 pneumonia patients than in COVID-19 pneumonia patients (p&lt;0.001). 26.2% of non-COVID-19 pneumonia patients, all of COVID-19 pneumonia patients' liver function tests, and coagulation factors were regularly monitored. COVID-19 pneumonia patients received %100 of patients antiviral drugs, 74.1% of patients corticosteroids, 92.5% of patients anticoagulant, 39.5% psychological support different from non-COVID-19 patients. Conclusion D-dimer and procalcitonin elevation in patients who develop pneumonia due to COVID-19 may be indicators of the need for intensive care in nursing care. Besides, it was concluded that liver functions and DVT follow-up in COVID-19 pneumonia should be included in nursing care.

Sex-Dependent Performance of the Neutrophil-to-Lymphocyte, Monocyte-to-Lymphocyte, Platelet-to-Lymphocyte and Mean Platelet Volume-to-Platelet Ratios in Discriminating COVID-19 Severity.

BackgroundThe neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and mean platelet volume-to-platelet ratio (MPR) are combined hematology tests that predict COVID-19 severity, although with different cut-off values. Because sex significantly impacts immune responses and the course of COVID-19, the ratios could be biased by sex.PurposeThis study aims to evaluate sex-dependent differences in the contribution of NLR, PLR, MLR, and MPR to COVID-19 severity and mortality upon hospital admission using a sample of pneumonia patients with SARS-CoV-2 infection.MethodsThis single-center observational cross-sectional study included 3,280 confirmed COVID-19 cases (CDC 2019-Novel Coronavirus real-time RT-PCR Diagnostic) from Quito (Ecuador). The receiver operating characteristic (ROC) curve analysis was conducted to identify optimal cut-offs of the above parameters when discriminating severe COVID-19 pneumonia and mortality risks after segregation by sex. Severe COVID-19 pneumonia was defined as having PaO2 < 60 mmHg and SpO2 < 94%, whereas non-severe COVID-19 pneumonia was defined as having PaO2 ≥ 60 mmHg and SpO2 ≥ 94%.ResultsThe mortality rate of COVID-19 among men was double that in women. Severe COVID-19 pneumonia and non-surviving patients had a higher level of NLR, MLR, PLR, and MPR. The medians of NLR, MLR, and MPR in men were significantly higher, but PLR was not different between men and women. In men, these ratios had lower cut-offs than in women (NLR: 2.42 vs. 3.31, MLR: 0.24 vs. 0.35, and PLR: 83.9 vs. 151.9). The sensitivity of NLR, MLR, and PLR to predict pneumonia severity was better in men (69–77%), whereas their specificity was enhanced in women compared to men (70–76% vs. 23–48%).ConclusionThese ratios may represent widely available biomarkers in COVID-19 since they were significant predictors for disease severity and mortality although with different performances in men and women.

PixelPrint: Three-dimensional printing of realistic patient-specific lung phantoms for CT imaging.

Phantoms are essential tools for assessing and verifying performance in computed tomography (CT). Realistic patient-based lung phantoms that accurately represent textures and densities are essential in developing and evaluating novel CT hardware and software. This study introduces PixelPrint, a 3D-printing solution to create patient-specific lung phantoms with accurate contrast and textures. PixelPrint converts patient images directly into printer instructions, where density is modeled as the ratio of filament to voxel volume to emulate local attenuation values. For evaluation of PixelPrint, phantoms based on four COVID-19 pneumonia patients were manufactured and scanned with the original (clinical) CT scanners and protocols. Density and geometrical accuracies between phantom and patient images were evaluated for various anatomical features in the lung, and a radiomic feature comparison was performed for mild, moderate, and severe COVID-19 pneumonia patient-based phantoms. Qualitatively, CT images of the patient-based phantoms closely resemble the original CT images, both in texture and contrast levels, with clearly visible vascular and parenchymal structures. Regions-of-interest (ROIs) comparing attenuation demonstrated differences below 15 HU. Manual size measurements performed by an experienced thoracic radiologist revealed a high degree of geometrical correlation between identical patient and phantom features, with differences smaller than the intrinsic spatial resolution of the images. Radiomic feature analysis revealed high correspondence, with correlations of 0.95-0.99 between patient and phantom images. Our study demonstrates the feasibility of 3D-printed patient-based lung phantoms with accurate geometry, texture, and contrast that will enable protocol optimization, CT research and development advancements, and generation of ground-truth datasets for radiomic evaluations.

Think positive: An interpretable neural network for image recognition

The COVID-19 pandemic is an ongoing pandemic and is placing additional burden on healthcare systems around the world. Timely and effectively detecting the virus can help to reduce the spread of the disease. Although, RT-PCR is still a gold standard for COVID-19 testing, deep learning models to identify the virus from medical images can also be helpful in certain circumstances. In particular, in situations when patients undergo routine X-rays and/or CT-scans tests but within a few days of such tests they develop respiratory complications. Deep learning models can also be used for pre-screening prior to RT-PCR testing. However, the transparency/interpretability of the reasoning process of predictions made by such deep learning models is essential. In this paper, we propose an interpretable deep learning model that uses positive reasoning process to make predictions. We trained and tested our model over the dataset of chest CT-scan images of COVID-19 patients, normal people and pneumonia patients. Our model gives the accuracy, precision, recall and F-score equal to 99.48%, 0.99, 0.99 and 0.99, respectively.

Recognition of COVID-19 Pneumonia in Patients Performing Different Interventional Radiological Procedures of The Chest

Recognition of COVID-19 Pneumonia in Patients Performing Different Interventional Radiological Procedures of The Chest