CT findings of 795 COVID-19 positive cases: a multicenter study in Egypt

Background One year has passed since the announcement of COVID-19 as a pandemic and two waves had already stricken Egypt. The authors witnessed several atypical radiological features through the second pandemic wave, either early at the active infective stage or delayed at the post-infectious convalescent period. They believed every radiologist should be familiar with these features. Therefore, they performed this comparative study on 2000 Egyptian patients using multi-slice computed tomography (MSCT) to highlight the radiological differences between the first and second pandemic waves and correlate them to the clinical status. Results This random multi-center comparative study was retrospectively conducted on 2000 COVID-19 Egyptian patients; 1000 patients were registered at the first pandemic wave from April 2020 till September 2020, while the other 1000 patients were registered at the second pandemic wave from October 2020 till March 2020. Follow up CT examinations were performed for 49 and 122 patients through the first and second pandemic waves respectively. MSCT examinations were carefully evaluated by four expert consulting radiologists who came to a consensus. Meanwhile, the correlation with the clinical outcome was performed by two consulting pulmonologists. During the second pandemic wave, the prevalence rate of the “crazy-paving” pattern had significantly increased by 1.3 times (P value = 0.002). Additionally, the prevalence rate of the “air-bubble” sign had significantly increased by 1.9 times (P value = 0.02). Similarly, the presence of enlarged mediastinal lymph nodes (> 1 cm in short-axis diameter) had significantly increased by 1.7 times (P value = 0.036). Furthermore, the prevalence rate of pericardial effusion had significantly increased by 2.5 times (P value = 0.003). The above-mentioned signs were correlated to increased clinical severity and higher rates of hospitalization. Unexpectedly, other atypical radiological signs were only encountered through the second pandemic wave, including bronchiectatic changes (2.5%), “head-cheese” pattern (0.8%), cavitation (0.5%), and “bulls-eye” sign (0.2%). The prevalence rate of post-COVID fibrosis had doubled through the second wave but not in a significant way (P value = 0.234). Secondary fungal infection was only encountered throughout the second pandemic wave in four patients. COVID-19 reinfection was encountered in a single patient only during the second pandemic wave. Conclusion After 1 year from the announcement of COVID-19 as a pandemic, the radiological presentation of COVID-19 patients showed some significant differences between its first and second waves.

Section: Discussionsupporting

confidence: 92%

COVID-19 in Egypt after a year: the first and second pandemic waves from the radiological point of view; multi-center comparative study on 2000 patients

Samir

El-Abd

Mohamed

et al. 2021

“…These findings were mostly observed in bilateral, peripheral, and lower lobe distributions. Similar results have been reported in different studies, and other CT findings such as crazy-paving pattern, halo and reversed halo sign, air bubble sign, subpleural curvilinear line, air bronchogram, airway changes, and fibrous stripe formations have been described [ 13 , 14 , 15 ]. Similar to these findings in the literature, GGO, GGO + consolidation, and consolidation were the most common lesion patterns in both groups examined in our study.…”

Section: Discussionsupporting

confidence: 89%

Chest CT in COVID-19 pneumonia: correlations of imaging findings in clinically suspected but repeatedly RT-PCR test-negative patients

Korkmaz

Dikmen

Keleş

et al. 2021

Background To emphasize the importance of CT in the diagnosis of COVID-19 disease by comparing the thoracic CT findings of COVID-19 patients with positive RT-PCR results and patients with clinical suspicion of COVID-19 but with negative RT-PCR results. Results In our study, COVID-19 patients with positive RT-PCR results (RT-PCR (+) group) and patients with clinical suspicion of COVID-19 but negative RT-PCR results (RT-PCR (−) group) were compared in terms of CT findings. In CT images, ground-glass opacity and ground-glass opacity + patchy consolidation were the most common lesion patterns in both groups. No statistically significant differences in the rates and types of lesion patterns were observed between the two groups. In both groups, lesion distributions and distribution patterns were similarly frequent in the bilateral, peripheral, and lower lobe distributions. Among the 39 patients who underwent follow-up CT imaging in the first or second month, a regression in lesion number and density was detected in 18 patients from both groups. Consolidations were completely resorbed in 16 of these patients, and five patients had newly developed fibrotic changes. The follow-up CT examination of 16 patients was normal. Conclusions Due to the false-negative rate of RT-PCR tests caused by various reasons, clinically suspected COVID-19 patients with a contact history should be examined with CT scans, even if RT-PCR tests are negative. If the CT findings are positive, these patients should not be removed from isolation.

“…The CT features of COVID-19 pneumonia in our study are compatible with that published in the literature [ 20 – 23 ]. Ground glass opacities were the most common CT chest radiological finding with bilateral peripheral/subpleural predilection.…”

Section: Discussionsupporting

confidence: 90%

Comparative evaluation of semi-quantitative CT-severity scoring versus serum lactate dehydrogenase as prognostic biomarkers for disease severity and clinical outcome of COVID-19 patients

Magdy

Saad

Khateeb

et al. 2021

Background Coronavirus disease 2019 pandemic causes significant strain on healthcare infrastructure and medical resources. So, it becomes crucial to identify reliable predictor biomarkers for COVID-19 disease severity and short term mortality. Many biomarkers are currently investigated for their prognostic role in COVID-19 patients. Our study is retrospective and aims to evaluate role of semi-quantitative CT-severity scoring versus LDH as prognostic biomarkers for COVID-19 disease severity and short-term clinical outcome. Results Two hundred sixty-six patients between April 2020 and November 2020 with positive RT-PCR results underwent non-enhanced CT scan chest in our hospital and were retrospectively evaluated for CT severity scoring and serum LDH level measurement. Data were correlated with clinical disease severity. CT severity score and LDH were significantly higher in severe and critical cases compared to mild cases (P value < 0.001). High predictive significance of CT severity score for COVID-19 disease course noted, with cut-off value ≥ 13 highly predictive of severe disease (96.96% accuracy); cut-off value ≥ 16 highly predictive of critical disease (94.21% accuracy); and cut-off value ≥ 19 highly predictive of short-term mortality (92.56% accuracy). CT severity score has higher sensitivity, specificity, positive, and negative predictive values as well as overall accuracy compared to LDH level in predicting severe, critical cases, and short-term mortality. Conclusion Semi-quantitative CT severity scoring has high predictive significance for COVID-19 disease severity and short-term mortality with higher sensitivity, specificity, and overall accuracy compared to LDH. Our study strongly supports the use of CT severity scoring as a powerful prognostic biomarker for COVID-19 disease severity and short-term clinical outcome to allow triage of need for hospital admission, earlier medical interference, and to effectively prioritize medical resources for cases with high mortality risk for better decision making and clinical outcome.