Lung vessel volume evaluated with CALIPER software is an independent predictor of mortality in COVID-19 patients: a multicentric retrospective analysis

Abstract

Introduction Computer-Aided Lung Informatics for Pathology Evaluation and Ratings (CALIPER) software has already been widely used in the evaluation of interstitial lung diseases (ILD) but has not yet been tested in patients affected by COVID-19. Our aim was to use it to describe the relationship between Coronavirus Disease 2019 (COVID-19) outcome and the CALIPER-detected pulmonary vascular-related structures (VRS). Materials and methodsWe performed a multicentric retrospective study enrolling 570 COVID-19 patients who performed a chest CT in emergency settings in two different institutions. Fifty-three age-and sex-matched healthy controls were also identified. Chest CTs were analyzed with CALIPER identifying the percentage of VRS over the total lung parenchyma. Patients were followed for up to 72 days recording mortality and required intensity of care. Results There was a statistically significant difference in VRS between COVID-19-positive patients and controls (median (iqr) 4.05 (3.74) and 1.57 (0.40) respectively, p = 0.0001). VRS showed an increasing trend with the severity of care, p < 0.0001. The univariate Cox regression model showed that VRS increase is a risk factor for mortality (HR 1.17, p < 0.0001). The multivariate analysis demonstrated that VRS is an independent explanatory factor of mortality along with age (HR 1.13, p < 0.0001). Conclusion Our study suggests that VRS increases with the required intensity of care, and it is an independent explanatory factor for mortality. Key Points• The percentage of vascular-related structure volume (VRS) in the lung is significatively increased in COVID-19 patients.• VRS showed an increasing trend with the required intensity of care, test for trend p< 0.0001.• Univariate and multivariate Cox models showed that VRS is a significant and independent explanatory factor of mortality.

Accuracy of artificial intelligence CT quantification in predicting COVID-19 subjects’ prognosis

“…In another investigation, AI was harnessed to identify pulmonary vascular-related structures (VRS). This study revealed a correlation between the intensity of care required and an increase in VRS, which emerged as an independent explanatory factor for mortality [29]. The AI system's comparable performance against radiologist-assessed values in predicting clinical outcomes could represent a game-changer for resource-constrained settings [25].…”

Quantitative CT Texture Analysis of COVID-19 Hospitalized Patients during 3–24-Month Follow-Up and Correlation with Functional Parameters

“…CALIPER has been utilized in studying interstitial lung disease abnormalities, including its potential as an independent predictor of survival in idiopathic pulmonary fibrosis [ 21 ]. Romei et al first used CALIPER to assess CT scans of COVID-19 pneumonia, and the VRS was demonstrated to be associated with mortality [ 22 ].…”

“…The percentage of ILD was defined as the sum of the percentages of GGO, reticular abnormalities and honeycombing [ 20 ]. CALIPER allows the computing of the vascular-related structure (VRS) volume, defined as the volume of pulmonary vessels and contiguous-related structures, as perivascular fibrosis [ 22 ]. To calculate this parameter, the software utilizes the eigenvalues of the Hessian matrix, with the purpose being to achieve an optimized multiscale filter enhancing tubular structures, such as pulmonary vessels with a diameter larger than 3 mm.…”

Radiomics Applications in Spleen Imaging: A Systematic Review and Methodological Quality Assessment

“…Finally, another clinical scenario where radiomic features extracted from the spleen were helpful in clinical decision making is COVID-19. The value of lung parenchymal quantitative imaging biomarkers for COVID-19 diagnosis and severity assessment has been already widely proven in the literature [ 39 , 40 , 41 ]. However, COVID-19 is known to also involve other organs [ 42 ].…”