Model based quantification of visceral and subcutaneous abdominal adipose tissue volume on CT data

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Introduction Abdominal obesity is associated with increased risk for morbidity. The quantification of visceral and subcutaneous abdominal fat volume is an important task. Purpose The present study aims to deploy and evaluate a method for the direct quantification of visceral (VAF) and subcutaneous abdominal fat (SAF) volume on CT data, based on a parallel trapezium geometrical model. Materials and methods VAF and SAF volume estimations were performed on abdominal CT scans from 10 consecutive patients through systematic slice sampling using a sampling intensity of 1/10. Areas of VAF and SAF were defined on 4 or 5 slices of the complete abdominal imaging with a fixed HU threshold. Thereafter, the volumes were calculated assuming a linear variation of the fat area between consecutive slices and a parallel trapezium shape for the tissues of interest. The obtained estimations were compared with respective volumes measured on the entire abdominal image sets by the reference technique of manual planimetry. Results VAF and SAF volumes measured by the proposed model did not statistically differ from the planimetric reference volumes (VAF: P = 0.543; SAF: P = 0.568). Correlations between the estimates of the two methods were found to be strong (VAF: r = 0.996; SAF: r = 0.988). The 95% limits of agreement between the two techniques, evaluated by Bland–Altman plots, were acceptable (VAF: −23.4%, +13.2%; SAF: −14.8%, +10.9%). The measuring process of the model-based method did not exceed 4 min per subject. Conclusion The adoption of the parallel trapezium model may reduce the user effort, providing accurate quantification of abdominal fat volumes.