Opportunistic retrospective assessment of HUAC, bone density, SFT and breast density on CT images and relationship with severity of COVID-19

Aim. To evaluate mean Hounsfield unit calculation (HUAC), bone density, subcutaneous fat thickness (SFT), breast density (constitutional imaging biomarkers) and age in symptomatic patients with COVID-19, to assess their correlation with pneumonia severity. Materials and Methods. Between 11 March and 30 May 2020, 272 consecutive symptomatic female patients with COVID-19 who underwent chest CT imaging at baseline were reviewed. HUAC, bone density, SFT and breast density were evaluated retrospectively and statistically compared in cases with negative/positive PCR test results, with/without pneumonia and with mild/moderate-severe pneumonia. Univariate/multivariate logistic regression analyses were applied for estimation of moderate/severe pneumonia. Results. The parameters of age, HUAC, bone density, SFT and breast density were significantly different between patients with/without pneumonia. Additionally, the patients with moderate-severe pneumonia were older, had lower bone density, lower HUAC values, greater SFT and mostly fatty breast density. ROC analysis showed the highest AUC values of 0.763 and 0.744 for age and HUAC, respectively. A combination of HUAC and age was the most accurate model for estimation of moderate/severe pneumonia on logistic regression. Good intraobserver and interobserver reliabilities were detected. Conclusions. The severity of COVID-19 pneumonia among adult females was associated with older age, lower bone density, a lower HUAC value, greater SFT and fatty breast parenchyma. All these factors can be responsible for 21.9% of the development of moderate/severe pneumonia.