Differential diagnosis of COVID-19 at the chest computed tomography scan:A review with special focus on cancer patients

BACKGROUND Given the several radiological features shared by coronavirus disease 2019 pneumonia and other infective or non-infective diseases with lung involvement,the differential diagnosis is often tricky,and no unequivocal tool exists to help the radiologist in the proper diagnosis.Computed tomography is considered the gold standard in detecting pulmonary illness caused by severe acute respiratory syndrome coronavirus 2.AIM To conduct a systematic review including the available studies evaluating computed tomography similarities and discrepancies between coronavirus disease 2019 pneumonia and other pulmonary illness,then providing a discussion focus on cancer patients.METHODS Using pertinent keywords,we performed a systematic review using PubMed to select relevant studies published until October 30,2020.RESULTS Of the identified 133 studies,18 were eligible and included in this review.CONCLUSION Ground-glass opacity and consolidations are the most common computed tomography lesions in coronavirus disease 2019 pneumonia and other respiratory diseases.Only two studies included cancer patients,and the differential diagnosis with early lung cancer and radiation pneumonitis was performed.A single lesion associated with pleural effusion and lymphadenopathies in lung cancer and the onset of the lesions in the radiation field in the case of radiation pneumonitis allowed the differential diagnosis.Nevertheless,the studies were heterogeneous,and the type and prevalence of lesions,distributions,morphology,evolution,and additional signs,together with epidemiological,clinical,and laboratory findings,are crucial to help in the differential diagnosis.

Review on radiological evolution of COVID-19 pneumonia using computed tomography

BACKGROUND Pneumonia is the main manifestation of coronavirus disease 2019(COVID-19)infection.Chest computed tomography is recommended for the initial evaluation of the disease;this technique can also be helpful to monitor the disease progression and evaluate the therapeutic efficacy.AIM To review the currently available literature regarding the radiological follow-up of COVID-19-related lung alterations using the computed tomography scan,to describe the evidence about the dynamic evolution of COVID-19 pneumonia and verify the potential usefulness of the radiological follow-up.METHODS We used pertinent keywords on PubMed to select relevant studies;the articles we considered were published until October 30,2020.Through this selection,69 studies were identified,and 16 were finally included in the review.RESULTS Summarizing the included works’findings,we identified well-defined stages in the short follow-up time frame.A radiographic deterioration reaching a peak roughly within the first 2 wk;after the peak,an absorption process and repairing signs are observed.At later radiological follow-up,with the limitation of little evidence available,the lesions usually did not recover completely.CONCLUSION Following computed tomography scan evolution over time could help physicians better understand the clinical impact of COVID-19 pneumonia and manage the possible sequelae;a longer follow-up is advisable to verify the complete resolution or the presence of long-term damage.