Organizing pneumonia-like pattern in COVID-19.

INTRODUCTION: Organizing pneumonia (OP) is a radio-histologic pattern that forms in response to lung damage in patients with focal or diffuse lung injury. OP is frequently observed subsequent to viral-induced lung damage and is associated with a diverse range of clinical outcomes. MATERIAL AND METHODS: We included 210 patients (mean age: 55.8 ± 16.5 years old; 61% male) with mild Coronavirus disease 2019 (COVID-19) who underwent chest computed tomography (CT) from 25 February to 22 April, 2020. The patients were divided into two groups based on the presence (n = 103) or absence of typical OP-like pattern (n =107) on initial chest CT. The extent of lung involvement and final outcome was compared across the two groups. Serial changes in imaging were also evaluated in 36 patients in the OP-group with a second CT scan. RESULTS: Duration from symptom onset to presentation was significantly higher in the OP group (7.07 ± 3.71 versus 6.13 ± 4.96 days, p = 0.008). A higher COVID-19-related mortality rate was observed among patients with OP-like pattern (17.5% vs 3.7%, p = 0.001).There was no significant difference in the overall involvement of the lungs (p = 0.358), but lower lobes were significantly more affected in the OP group (p < 0.001). Of the 36 patients with follow-up imaging (mean duration of follow-up = 8.3 ± 2.1 days), progression of infiltration was seen in more than 61% of patients while lesions had resolved in only 22.2% of cases. CONCLUSIONS: Our observation indicates that physicians should carefully monitor for the presence of OP-like pattern on initial CT as it is associated with a poor outcome. Furthermore, we recommend interval CT to evaluate the progression of infiltrations in these patients.

The Association of CT-measured Cardiac Indices with Lung Involvement and Clinical Outcome in Patients with COVID-19.

RATIONALE AND OBJECTIVES: Cardiac indices can predict disease severity and survival in a multitude of respiratory and cardiovascular diseases. Herein, we hypothesized that CT-measured cardiac indices are correlated with severity of lung involvement and can predict survival in patients with COVID-19. MATERIALS AND METHODS: Eighty-seven patients with confirmed COVID-19 who underwent chest CT were enrolled. Cardiac indices including pulmonary artery-to-aorta ratio (PA/A), cardiothoracic ratio (CTR), epicardial adipose tissue (EAT) thickness and EAT density, inferior vena cava diameter, and transverse-to-anteroposterior trachea ratio were measured by non-enhanced CT. Logistic regression and Cox-regression analyses evaluated the association of cardiac indices with patients' outcome (death vs discharge). Linear regression analysis was used to assess the relationship between the extent of lung involvement (based on CT score) and cardiac indices. RESULTS: Mean (±SD) age of patients was 54.55 (±15.3) years old; 65.5% were male. Increased CTR (>0.49) was seen in 52.9% of patients and was significantly associated with increased odds and hazard of death (odds ratio [OR] = 12.5, p = 0.005; hazard ratio = 11.4, p = 0.006). PA/A >1 was present in 20.7% of patients and displayed a nonsignificant increase in odds of death (OR = 1.9, p = 0.36). Furthermore, extensive lung involvement was positively associated with elevated CTR and increased PA/A (p = 0.001). CONCLUSION: CT-measured cardiac indices might have predictive value regarding survival and extent of lung involvement in hospitalized patients with COVID-19 and could possibly be used for the risk stratification of these patients and for guiding therapy decision-making. In particular, increased CTR is prevalent in patients with COVID-19 and is a powerful predictor of mortality.

Epicardial adipose tissue, inflammatory biomarkers and COVID-19: Is there a possible relationship?

BACKGROUND & AIMS: Adipose tissue is a biologically active organ with pro-immunogenic properties. We aimed to evaluate the prognostic value of epicardial adipose tissue (EAT) in COVID-19 and its correlation with other inflammatory biomarkers. MATERIAL AND METHODS: One-hundred patients with COVID-19 were enrolled. C-reactive protein (CRP), lactate dehydrogenase (LDH), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-CRP ratio (LCR), and platelet-to-lymphocyte ratio (PLR) were evaluated on admission. EAT volume and density were measured by computed tomography. Patients were followed until death or discharge. Univariate and multivariate analysis was performed and ROC curve analysis was used to assess the ability of inflammatory markers in predicting survival. The relationship between EAT and other inflammatory markers was also investigated. RESULTS: The mean ± SD age of patients was 55.5 ± 15.2 years old; 68% were male. Univariate analysis revealed that increased lung involvement, blood urea nitrogen, LDH and NLR, and decreased platelet count were significantly associated with death. After adjustment, LDH was independently predictive of death (OR = 1.013, p-value = 0.03). Among inflammatory markers, LCR had the best ability for predicting survival with 79.7% sensitivity and 64.3% specificity at an optimal cut-off value of 20.8 (AUC = 0.744, 95% CI = 0.612-0.876, p-value = 0.004). EAT volume demonstrated positive correlation with NLR and PLR (p = 0.001 and 0.01), and a negative correlation with LCR (p = 0.02). EAT density was significantly different between decedents and survivors (p = 0.008). CONCLUSION: Routine laboratory tests that represent status of inflammation can be used as cost-effective prognostic markers of COVID-19. Also, the significant association between EAT volume and other inflammatory biomarkers might explain the more severe disease in obese patients.

Correlation Between Low-Dose Chest Computed Tomography and RT-PCR Results for the Diagnosis of COVID-19: A Report of 27,824 Cases in Tehran, Iran.

RATIONALE AND OBJECTIVES: Real-time polymerase chain reaction (RT-PCR) remains the gold standard for confirmation of Coronavirus Disease 2019 (COVID-19) despite having many disadvantages. Here, we investigated the diagnostic performance of chest computed tomography (CT) as an alternative to RT-PCR in patients with clinical suspicion of COVID-19 infection. METHODS: In this descriptive cross-sectional study, 27,824 patients with clinical suspicion of COVID-19 infection who underwent unenhanced low-dose chest CT from 20 February, 2020 to 21 May, 2020 were evaluated. Patients were recruited from seven specifically designated hospitals for patients with COVID-19 infection affiliated to Shahid Beheshti University of Medical Sciences. In each hospital, images were interpreted by two independent radiologists. CT findings were considered as positive/negative for COVID-19 infection based on RSNA diagnostic criteria. Then, the correlation between the number of daily positive chest CT scans and number of daily PCR-confirmed cases and COVID-19-related deaths in Tehran province during this three-month period was assessed. The trends of admission rate and patients with positive CT scans were also evaluated. RESULTS: A strong positive correlation between the numbers of daily positive CT scans and daily PCR-confirmed COVID-19 cases (r = 0.913, p < 0.001) was observed. Furthermore, in hospitals located in regions with a lower socioeconomic status, the admission rate and number of positive cases within this three-month period was higher as compared to other hospitals. CONCLUSION: Low-dose chest CT is a safe, rapid and reliable alternative to RT-PCR for the diagnosis of COVID-19 in high-prevalence regions. In addition, our study provides further evidence for considering patients' socioeconomic status as an important risk factor for COVID-19.

Clinical and Radiologic Characteristics of COVID-19 in Patients With CKD

INTRODUCTION: In this study, we aimed to evaluate the presentation and outcome of COVID-19 in patients with chronic kidney disease (CKD). METHODS: We included 43 patients with a past history of CKD and confirmed diagnosis of COVID-19. Patients were evaluated for demographic characteristics, clinical and laboratory data and findings of initial chest computed tomography (CT) and were followed until either death or discharge occurred. Then, study variables were compared based on final outcome and stage of CKD. RESULTS: Mean age +/- SD of patients was 60.65 +/- 14.36 years;65.1% were male. Five of 43 patients (11.6%) died on follow-up and the rest were discharged. Disease outcome did not differ across CKD stages (P > .05). More than half of the patients (58.1%) presented with severe disease on admission. Clinical symptoms were similar to those of non-CKD individuals. Mean duration of hospitalization was higher in those who died, although not significant (16.6 +/- 8.38 vs. 11 +/- 6.26, P > .05). The only hematologic parameter that significantly differed between survivors and non-survivors was lactase dehydrogenase level (P < .05). Ground-glass opacification and reticular pattern were the most frequent patterns on CT and pleural effusion existed in about one-fifth of all patients. A greater lower zone score was noted in deceased patients (P < .05). CONCLUSION: Patients with CKD are vulnerable to a more severe form of COVID-19 and experience a higher mortality rate than the general population;however, higher CKD stage is not related to worse prognosis or different imaging manifestation compared with lower stage.

Lobar Distribution of COVID-19 Pneumonia Based on Chest Computed Tomography Findings; A Retrospective Study.

INTRODUCTION: Computed tomography (CT) imaging has quickly found its place as a beneficial tool in the detection of coronavirus disease 2019 (COVID-19). To date, only a few studies have reported the distribution of lung lesions by segment. This study aimed to evaluate the lobar and segmental distribution of COVID-19 pneumonia based on patients' chest CT scan. METHODS: This was a retrospective study performed on 63 Iranian adult patients with a final diagnosis of COVID-19. All patients had undergone chest CT scan on admission. Demographic data and imaging profile, including segmental distribution, were evaluated. Moreover, a scoring scale was designed to assess the severity of ground-glass opacification (GGO). The relationship of GGO score with age, sex, and symptoms at presentation was investigated. RESULTS: Among included patients, mean age of patients was 54.2 ±14.9 (range: 26 - 81) years old and 60.3% were male. Overall, the right lower lobe (87.3%) and the left lower lobe (85.7%) were more frequently involved. Specifically, predominant involvement was seen in the posterior segment of the left lower lobe (82.5%). The most common findings were peripheral GGO and consolidation, which were observed in 92.1% and 42.9% of patients, respectively. According to the self-designed GGO scoring scale, about half of the patients presented with mild GGO on admission. GGO score was found to be equally distributed among different sex and age categories; however, the presence of dyspnea on admission was significantly associated with a higher GGO score (p= 0.022). Cavitation, reticulation, calcification, bronchiectasis, tree-in-bud appearance and nodules were not identified in any of the cases. CONCLUSION: COVID-19 mainly affects the lower lobes of the lungs. GGO and consolidation in the lung periphery is the imaging hallmark in patients with COVID-19 infection. Absence of bronchiectasis, solitary nodules, cavitation, calcifications, tree-in-bud appearance, and reversed halo-sign indicates that these features are not common findings, at least in the earlier stages.