Agreement between low-dose and ultra-low-dose chest CT for the diagnosis of viral pneumonia imaging patterns during the COVID-19 pandemic

Background Chest CT scan has an important role in the diagnosis and management of COVID-19 infection. A major concern in radiologic assessment of the patients is the radiation dose. Research has been done to evaluate low-dose chest CT in the diagnosis of pulmonary lesions with promising findings. We decided to determine diagnostic performance of ultra-low-dose chest CT in comparison to low-dose CT for viral pneumonia during the COVID-19 pandemic. Results 167 patients underwent both low-dose and ultra-low-dose chest CT scans. Two radiologists blinded to the diagnosis independently examined ultra-low-dose chest CT scans for findings consistent with COVID-19 pneumonia. In case of any disagreement, a third senior radiologist made the final diagnosis. Agreement between two CT protocols regarding ground-glass opacity, consolidation, reticulation, and nodular infiltration were recorded. On low-dose chest CT, 44 patients had findings consistent with COVID-19 infection. Ultra-low-dose chest CT had sensitivity and specificity values of 100% and 98.4%, respectively for diagnosis of viral pneumonia. Two patients were falsely categorized to have pneumonia on ultra-low-dose CT scan. Positive predictive value and negative predictive value of ultra-low-dose CT scan were respectively 95.7% and 100%. There was good agreement between low-dose and ultra-low-dose methods (kappa = 0.97;P < 0.001). Perfect agreement between low-dose and ultra-low-dose scans was found regarding diagnosis of ground-glass opacity (kappa = 0.83, P < 0.001), consolidation (kappa = 0.88, P < 0.001), reticulation (kappa = 0.82, P < 0.001), and nodular infiltration (kappa = 0.87, P < 0.001). Conclusion Ultra-low-dose chest CT scan is comparable to low-dose chest CT for detection of lung infiltration during the COVID-19 outbreak while maintaining less radiation dose. It can also be used instead of low-dose chest CT scan for patient triage in circumstances where rapid-abundant PCR tests are not available.

Prevalence of clinical and radiologic features in methanol-poisoned patients with and without COVID-19 infection.

AIM: The aim of the current study was to evaluate the prevalence of coronavirus disease (COVID-19) in methanol-poisoned patients admitted to two toxicology academic centers during the COVID-19 outbreak and determine their clinical features and chest/brain computed tomography (CT) findings. METHODS: Methanol-poisoned patients who had been referred during the COVID-19 pandemic were evaluated for signs and symptoms of COVID-19 by chest CT scans and/or polymerase chain reaction test. RESULTS: A total of 62 patients with confirmed methanol poisoning were enrolled in the study, with a median (interquartile range) age of 35 (28-44) years. Thirty-nine (62.9%) survived. Nine (14.5%) were diagnosed to have COVID-19, of whom four survived. There was a significant correlation between COVID-19 disease and a history of alcohol consumption (p = 0.036; odds ratio 1.7; 95% confidence interval, 1.3-2.2). Univariate analysis showed significant differences between infected and noninfected patients regarding their urea and time for first and second hemodialysis sessions, as well as the duration of ethanol administration. CONCLUSIONS: In conclusion, during the pandemic, specific attention should be paid to patients with a history of alcohol ingestion and elevated creatinine, loss of consciousness, and severe acidosis as these signs/symptoms could be present in both COVID-19 and methanol poisoning, making differentiation between the two challenging.

Post-mortem Histopathologic Findings of Vital Organs in Critically Ill Patients with COVID-19.

BACKGROUND: The scientific evidence concerning pathogenesis and immunopathology of the coronavirus disease 2019 (COVID-19) is rapidly evolving in the literature. To evaluate the different tissues obtained by biopsy and autopsy from five patients who expired from severe COVID-19 in our medical center. METHODS: This retrospective study reviewed five patients with severe COVID-19, confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and imaging, to determine the potential correlations between histologic findings with patient outcome. RESULTS: Diffuse alveolar damage (DAD) and micro-thrombosis were the most common histologic finding in the lung tissues (4 of 5 cases), and immunohistochemical (IHC) findings (3 of 4 cases) suggested perivascular aggregation and diffuse infiltration of alveolar walls by CD4+ and CD8+ T lymphocytes. Two of five cases had mild predominantly perivascular lymphocytic infiltration, single cell myocardial necrosis and variable interstitial edema in myocardial samples. Hypertrophic cardiac myocytes, representing hypertensive cardiomyopathy was seen in one patient and CD4+ and CD8+ T lymphocytes were detected on IHC in two cases. In renal samples, acute tubular necrosis was observed in 3 of 5 cases, while chronic tubulointerstitial nephritis, crescent formation and small vessel fibrin thrombi were observed in 1 of 5 samples. Sinusoidal dilation, mild to moderate chronic portal inflammation and mild mixed macro- and micro-vesicular steatosis were detected in all liver samples. CONCLUSION: Our observations suggest that clinical pathology findings on autopsy tissue samples could shed more light on the pathogenesis, and consequently the management, of patients with severe COVID-19.

A Multicenter Survey on the Trend of Chest CT Scan Utilization: Tracing the First Footsteps of COVID-19 in Iran.

BACKGROUND: Chest computed tomography (CT) scan has been used widely to diagnose COVID-19 in Iran. OBJECTIVES: To trace the footsteps of COVID-19 in Iran by exploring the trend in using chest CT scans and its economic impact on radiology departments. Methods: In this cross-sectional study, the number of imaging examinations from 33 tertiary radiology departments in 9 large cities of Iran was collected from September 23, 2019 to March 20, 2020 (Months 1 to 6) and the corresponding months in 2018-2019. RESULTS: A 50.2% increase was noted in the chest CT scan utilization in 2019-2020 compared to 2018-2019. This increase was +15%, +15%, +27%, +2%, +1% in Months 1-5 of 2019-2020, respectively. In Month 6 of 2019-2020, a 251% increase in the acquisition of chest CT scans was observed compared to the Month 6 of 2018-2019. Following negative balance of revenue from Month 1 to 5 with respect to the inflation rate, the total income in Month 6 was further 1.5% less than the same Month in 2018-19. CONCLUSION: The observed peak in chest CT utilization in Month 3 prior to the surge in Month 6 could be explained by the seasonal influenza. However, unawareness about an emerging viral disease, i.e. COVID-19, might have underutilized chest CT in Months 4 and 5 before the official announcement in Month 6. The unbalanced increase in the workload of radiology departments in the shortage of cardiothoracic radiologists with the simultaneous decrease in income initiated a vicious cycle that worsened the economic repercussions of the pandemic.

Interferon beta-1a as a Candidate for COVID-19 Treatment;An Open Label Single-Arm Clinical Trial

Introduction: Since December 2019, an outbreak of Covid-19 has caused growing concern in multiple countries. Researchers around the world are working to find a treatment or a vaccine for Covid-19 and different treatment approaches have been tested in this regard. Objective: This study was designed and conducted to assess the possible efficacy of Interferon beta-1a as a safe and efficient candidate for Covid-19 treatment. Methods: This is an investigator-initiated, open-label, single-arm clinical trial. Twenty patients with suspected Covid-19, who were admitted to Sina hospital in Tehran, Iran, with moderate to severe symptoms, from 6 to 10 March, 2020, were enrolled. Patients were treated with antiviral and hydroxychloroquine combination therapy, along with subcutaneous Interferon beta-1a for 5 consecutive days. Baseline characteristics and findings during the course of admission and 5 days after discharge were recorded for all the patients. Results: In total, 20 patients with suspected Covid-19 were included in this study, 12 (60%) of which were male. The median (Interquartile (IQ) range) of patients' age was 55.5 (43-63.5). The most common symptom of the patients at onset of disease was fever. The median (IQ range) of duration of hospital stay was 5.0 (3-6) days. Only 2 cases were admitted to ICU. At the time of follow-up, 15 (94%) patients reported that they generally felt good and had oral tolerance, 1 patient had suffered from dyspnea, 5 patients had suffered from cough, none of them had experienced fever and no case of re-admission or death was reported after discharge. Conclusions: Results of the current study are in favor of using Interferon beta-la in addition to recommended antiviral treatment in Covid-19 patients.