Assessment Of Human Muscle And Fat Measured By Quantitative Computed Tomography

PurposeAbdominal scans of subjects with dual energy X-ray absorptiometry(DXA)were performed using quantitative computed tomography(QCT).The relationship between QCT parameters and DXA body or regional body composition was analyzed,and the prediction equations of body or regional body composition based on lumbar abdominal QCT were established.MethodA total of 139 subjects were enrolled and body composition parameters of different abdominal slices were obtained by QCT and body or regional body composition parameters were obtained by DXA total body scan.100 cases were randomly selected as equation group,and the remaining 39cases were selected as verification group.After gender grouping and different body mass index(BMI)levels grouping,correlation analysis and stepwise regression analysis were performed on the body composition parameters of QCT and DXA in the equation group,and the prediction equations of total body composition parameters were established.Finally,the prediction equations were cross-verified by the verification group.Results1.Total body fat percentage(TBF%)and Android fat percentage(Android%fat)had better accuracies in gender groups and non-obese groups(TBF%:R~2=0.635-0.867,Android%fat:R~2=0.757-0.976).In the prediction equations of Gynoid fat percentage(Gynoid%fat),only the male group had higher accuracy(R~2=0.752).When predicting fat mass index(FMI),the male group,normal group of body mass index(BMI)and overweight group of BMI had better accuracies of the prediction equations(R~2=0.714-0.884).2.The correlation coefficients of DXA-derived visceral fat volume(VFV)and QCT-derived VFV were high in all groups(r=0.828-0.968),and the correlation was strongest in male group(r=0.968).3.Correlation analysis found that most muscle parameters measured by QCT and DXA were low correlated.What’s more,it was not work to estimate total body or region muscle by QCT-derived muscle parameters.ConclusionsThis study confirmed that TBF%,Android%fat and Gynoid%fat and FMI can be assessed by abdominal QCT measurements,and visceral adipose tissue(VAT)can also be assessed by DXA-derived VFV in the southern Chinese population.