Influence of tube potential on CT body composition analysis

Abstract

Objectives: Our purpose was to investigate whether tube potential in contrast-enhanced computed tomography (CT) affects body composition analysis.

Methods: Images from dual-source, dual-energy CT from the abdomen with intravenous contrast media administration were used. A total of 17 patients (11 women, mean age 52) with a mean body mass index of 20.8 kg/cm² were included. Simultaneously acquired images with a tube voltage of 80 kV and 140 kV were compared. Body composition was analyzed on a single slice at the L3 level. Parameters evaluated included muscle and fat attenuation (Hounsfield units [HU]), skeletal muscle index (cm²/m²), muscle area (cm²), and steatotic muscle area (cm²). Significant differences between 80 kV and 140 kV series were compared using the paired Student's t test.

Results: Tube potential affected muscle attenuation with an average difference of 17% between 80 kV and 140 kV series (48 HU versus 41 HU, P < 0.01), fat attenuation (-84 HU versus -69 HU, P < 0.01), skeletal muscle index of 5.2% (40.1 cm²/m² versus 42.2 cm²/m², P < 0.01), muscle area of 5.1% (117 cm² versus 123 cm², P < 0.01), and steatotic muscle area of 12.9% (31 cm² versus 35 cm², P < 0.01).

Conclusion: Tube potential significantly affects body segmentation in contrast-enhanced CT.

Keywords: Body composition; Computed tomography; Fat; Muscle; Segmentation; Skeletal muscle index.