Time Course of Chest Computed Tomography Findings and Biomarkers in COVID-19 Pneumonia Patients

RATIONALE: Chest computed tomography (CT) has a potential role in the diagnosis, detection of complications, and prognosis of coronavirus disease 2019 (COVID-19). The value of chest CT can be further amplified when associated to physiological variables. Some studies have done efforts to correlate chest CT findings with overall oxygenation and respiratory mechanics, which although they are easily obtained may not be specifically related to COVID-19. Very few studies have tried to correlate chest CT findings with specific biomarkers related to COVID-19. For this purpose, temporal changes of chest CT were evaluated and then correlated with laboratory data in multicenter randomized clinical trial. METHODS: Adult patients who presented chest CT scan features compatible with viral pneumonia were admitted in the hospital and followed during 7 days (NCT: 04561219). CT scans and laboratory data [D-dimer, ferritin, and lactate dehydrogenase (LDH)] in blood were obtained at the moment of admission (Baseline) and on day 7 (Final). Qualitative and quantitative chest CT scan parameters were evaluated in ventral, middle and dorsal regions of interest (ROI) and classified as: hyper-, normal-, poor-, and non-aerated. RESULTS: In this study involving 45 COVID-19 patients no statistically significant differences in the overall Hounsfield Units (HU) ranges and percent of whole lung mass were found overtime. Normally aerated lung tissue reduced from Baseline to Final (p=0.004), mainly associated with a decrease in ventral (p=0.001) and middle (p=0.026) ROIs. At dorsal ROI, a reduction in CT lung mass in poorly aerated areas was observed from Baseline to Final. Poorly aerated and non-aerated lung areas were well correlated only with D-dimer blood levels (r=0.55, p<0.001;and r=0.52, p=0.001, respectively). CONCLUSION: In patients with COVID-19 pneumonia, changes in poor-and non-aerated were associated to changes in D-dimer blood levels, which may be a specific biomarker to be follow in facilities without CT as a way to infer radiologic changes.