Abstract：
BACKGROUND: 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).
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
摘要：
背景：计算机断层扫描（CT）在临床环境中评估身体成分的潜力未得到充分利用。通常使用静脉造影（IVC）进行，由于对骨骼肌面积（SMA）的影响不清楚，CT扫描产生未使用的身体成分数据，骨骼肌指数（SMI），和肌肉密度（SMD）。
目的：本研究调查体重调整后的IVC是否会影响SMA，SMI,与无造影腹部CT相比，女性和男性的SMD不同。此外,该研究探讨了对比和非对比评估的SMA之间的关联，SMI,SMD,和人口因素。
方法：对连续进行了四期对比增强腹部CT扫描的丹麦患者进行了一项比较观察性回顾性研究（非对比，动脉，静脉,和晚期静脉阶段)。由三个独立的评估者使用经过验证的基于阈值的半自动软件评估肌肉测量。
结果：该研究包括72名患者（51名男性，21名女性），平均年龄59（55，62）岁。与非对比CT相比，经体重调整的IVC在静脉后期使SMA增加了3.28cm2（CI：2.58，3.98），相当于2.4％（1.8，2.9）。性别之间的分析表明，女性和男性之间IVC对SMA和SMI的影响没有差异。然而,与男性相比，女性在静脉期间的SMD平均增加了1.7HU0.9;2.5），静脉后期的平均HU为1.80（1.0;2.6）。多因素回归分析显示静脉期间SMD和性别的差异之间存在关联（-1.38，95CI：-2.48，-0.48）和静脉后期（-1.23，95％CI：-2.27，-0.19）结论：体重调整后的IVC导致SMA增加，SMI,和SMD。虽然SMA和SMI的性别差异是一致的，在静脉和静脉后期，女性的SMD增加明显高于男性。需要进一步的研究来确定SMD作为IVCCT扫描中肌肉质量代理的适用性。
目的：本研究调查体重调整后的IVC是否会影响SMA，SMI,与无造影腹部CT相比，女性和男性的SMD不同。此外,该研究探讨了对比和非对比评估的SMA之间的关联，SMI,SMD,和人口因素。
方法：对连续进行了四期对比增强腹部CT扫描的丹麦患者进行了一项比较观察性回顾性研究（非对比，动脉，静脉,和晚期静脉阶段)。由三个独立的评估者使用经过验证的基于阈值的半自动软件评估肌肉测量。
结果：该研究包括72名患者（51名男性，21名女性），平均年龄59（55，62）岁。与非对比CT相比，经体重调整的IVC在静脉后期使SMA增加了3.28cm2（CI：2.58，3.98），相当于2.4％（1.8，2.9）。性别之间的分析表明，女性和男性之间IVC对SMA和SMI的影响没有差异。然而,与男性相比，女性在静脉期间的SMD平均增加了1.7HU0.9;2.5），静脉后期的平均HU为1.80（1.0;2.6）。多因素回归分析显示静脉期间SMD和性别的差异之间存在关联（-1.38，95CI：-2.48，-0.48）和静脉后期（-1.23，95％CI：-2.27，-0.19）结论：体重调整后的IVC导致SMA增加，SMI,和SMD。虽然SMA和SMI的性别差异是一致的，在静脉和静脉后期，女性的SMD增加明显高于男性。需要进一步的研究来确定SMD作为IVCCT扫描中肌肉质量代理的适用性。
