Influence of CT parameters upon the quantification of sarcopenia and myosteatosis: a study with human bodies

Computed tomography (CT) is increasingly being used in the quantitative assessment of body composition (CT-assessed sarcopenia and myosteatosis), but the effects of varying technical CT parameters on muscle area and density measurements remain unclear. This study analyzed muscle area and density in six human bodies scanned with varying CT parameters (tube current, tube voltage, slice thickness, and iterative reconstruction levels). Significance of differences relative to our institution’s standard CT abdomen protocol and among all individual parameters was assessed, with effect sizes calculated to evaluate the magnitude of observed changes. Small but significant differences were found within all groups of investigated parameters, with most statistical significant differences corresponding to large effect sizes. Compared to our institution’s clinical protocol, tube current showed significant variation in measured muscle area (p < 0.001), but no significant changes in regard to muscle density. Tube voltage and reconstruction level type both showed a significant direct relationship with muscle area (p < 0.001) and inverse relationship with muscle density (p < 0.001). Also, a slice thickness of 0.6 mm, compared to 1 mm, showed significant differences in both muscle area and density (p < 0.001), where no significant variation was observed between 1 mm and thicker slices. In conclusion, CT technical parameters significantly affect muscle area and density measurements. Although individual differences are small, their cumulative effect may lead to clinically significant discrepancies.