{Reference Type}: Journal Article
{Title}: Influence of weight-adjusted contrast enhancement on CT-derived skeletal muscle measures: A retrospective proof-of concept comparative study between Danish females and males.
{Author}: Brath MSG;Kristensen SV;Sahakyan M;Mark EB;Rasmussen HH;Østergaard LR;Frøkjær JB;Weinreich UM;
{Journal}: Am J Clin Nutr
{Volume}: 0
{Issue}: 0
{Year}: 2024 Jun 25
{Factor}: 8.472
{DOI}: 10.1016/j.ajcnut.2024.06.009
{Abstract}: <B>BACKGROUND: </B>Computed Tomography (CT) has an underutilized potential for evaluating body composition in clinical settings. Often conducted with intravenous contrast (IVC), CT scans yield unused body composition data due to unclear effects on skeletal muscle area (SMA), skeletal muscle index (SMI), and muscle density (SMD).<BR><B>OBJECTIVE: </B>This study investigates whether weight-adjusted IVC influences SMA, SMI, and SMD differently in female and male compared to non-contrast abdominal CT. Additionally, the study explores associations between contrast and non-contrast assessed SMA, SMI, SMD, and demographic factors.<BR><B>METHODS: </B>A comparative observational retrospective study was conducted on Danish patients who underwent consecutive four-phased contrast-enhanced abdominal CT scans (non-contrast, arterial, venous, and late venous phases). Muscle measures were evaluated using validated semi-automated threshold-based software by three independent raters.<BR><B>RESULTS: </B>The study included 72 patients (51 male, 21 female) with a mean age of 59 (55, 62) years. Weight-adjusted IVC increased SMA by up to 3.28 cm2 (CI: 2.58, 3.98) corresponding to 2.4% (1.8, 2.9) in late venous phase compared to non-contrast CT. Analysis between sexes showed no difference in the effects of IVC on SMA and SMI between female and male. However, females exhibited a higher increase in SMD during the venous by a mean of 1.7 HU 0.9; 2.5) and late venous phases with a mean HU of 1.80 (1.0; 2.6) compared to males. Multivariate regression analysis indicated an association between the differences in SMD and sex during venous (-1.38 , 95%CI: - 2.48, -0.48) and late venous phases (-1.23, 95% CI: -2.27, -0.19) CONCLUSION: Weight-adjusted IVC leads to increased SMA, SMI, and SMD. While SMA and SMI differences were consistent across the sexes, females exhibited a significantly higher SMD increase than male in the venous and late venous phases. Further investigations are necessary to determine the applicability of SMD as a muscle quality proxy in IVC CT scans.