Quantification of Visceral Adipose Tissue (VAT) and Subcutaneous Adipose Tissue (SAT) Based on CT Scan Tissue Segmentation Associated with Urolithiasis Recurrence

Abstract

Introduction: The aim of this study is to applied CT scan-based tissue segmentation to measure visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volumes. Then, the ratio of both fat tissue volumes was calculated to get two more parameters: visceral fat volume ratio (VFVR) and subcutaneous fat volume ratio (SFVR). After that, the relationship between these factors and urolithiasis recurrence was examined using correlation analysis. Other parameters, which are the patient’s age and gender, were also tested for correlation analysis with urolithiasis recurrence. Finally, logistic regression analysis was performed to find the association between urolithiasis recurrence and the parameters (age, gender, VAT volume, SAT volume, VFVR and SFVR). Methods: This study was a retrospective cross-sectional study design using the images collected from CT Urology cases in the year 2019. The patients selected have a history of stone removal in 2014. The application used for CT tissue segmentation is 3D Slicer. Results: Urolithiasis recurrence shows medium and high degree of positive correlation with total fat volume, VAT volume, and VFVR (correlation coefficient, cc = 0.254, p = 0.023), (cc = 0.390, p< 0.001) and (cc = 0.688, p< 0.001), respectively and high degree of negative correlation with SFVR (cc = -0.688, p< 0.001). However, using logistic regression analysis, only VAT volume was significantly associated with urolithiasis recurrence (OR 1.11, 95% CI 1.01-1.22, p= 0.03), while the total fat volume, VFVR, and SFVR are not significant. Conclusion: CT scan-based tissue segmentation has a huge impact on fat volume quantification. This study confirms that VAT volume was strongly correlated with urolithiasis recurrence, indicating that VAT volume plays a more important role than SAT volume, total fat volume, VFVR and SFVR in the production of urinary stone. Thus, VAT volume can be further considered as a new independent risk factor for urolithiasis.