Division of Radiology, Department of Clinical Science, 206106Intervention and Technology at Karolinska Institutet, Stockholm, Sweden.
Department of Radiology, 379654Södersjukhuset, Stockholm, Sweden.
Acta Radiol. 2023 Feb;64(2):435-440. doi: 10.1177/02841851221079014. Epub 2022 Mar 10.
Although described in product monographs, the maximum contrast media (CM) dose at computed tomography (CT) varies among institutions.
To investigate whether an upper limit of 40 g of iodine in women and 50 g in men is sufficient or if there is a body weight (BW) dependence of mean hepatic enhancement (MHE) beyond those thresholds.
At our institution, CM injection duration is fixed to 30 s and dosed 600 mg iodine/kg up to 40 g in women and 50 g in men. Pre- and post-contrast hepatic attenuation values (HU) were retrospectively obtained in 200 women and 200 men with glomerular filtration rate >45 mL/min undergoing 18-flurodeoxyglucose PET-CT (18F-FDG PET-CT) of which half weighed below and half above those dose thresholds using iodixanol 320 mg iodine/mL or iomeprol 400 mg iodine/mL. The correlation between BW and MHE was assessed by simple linear regression.
Weight range was 41-120 kg in women and 47-137 kg in men. There was no significant relationship between MHE and BW in women receiving <40 g (r = -0.05, = 0.63) or in men receiving <50 g (r = 0.18, = 0.07). Above those thresholds there was an inverse relationship (r = -0.64, <0.001 in women and r = -0.30, <0.002 in men). There was no apparent upper limit where the dependence of hepatic MHE on BW decreased. Hepatosteatosis limited MHE.
Adjusting CM to BW diminishes the dependence of MHE on BW. There was no apparent upper limit for the relationship between BW and MHE in heavier patients at CM-enhanced CT.
尽管在产品说明书中有所描述，但计算机断层扫描（CT）的最大造影剂（CM）剂量在不同机构之间有所差异。
研究女性最大碘摄入量为 40g，男性最大碘摄入量为 50g 是否足够，或者在这些阈值之外，肝平均增强（MHE）是否与体重（BW）存在依赖关系。
在本机构，CM 注射时间固定为 30s，女性最大碘摄入量为 40g，男性最大碘摄入量为 50g，按 600mg 碘/kg 进行剂量注射。回顾性分析了 200 名肾小球滤过率（GFR）>45ml/min 的女性和 200 名男性患者的肝衰减值（HU），这些患者行 18-氟代脱氧葡萄糖正电子发射断层扫描（18F-FDG PET-CT），其中一半患者的体重低于或高于碘克沙醇 320mg 碘/ml 或碘普罗胺 400mg 碘/ml 的剂量阈值。采用简单线性回归评估 BW 与 MHE 的相关性。
女性的体重范围为 41-120kg，男性的体重范围为 47-137kg。在女性中，当接受碘摄入量<40g 时（r=-0.05，P=0.63）或男性接受碘摄入量<50g 时（r=0.18，P=0.07），MHE 与 BW 之间无显著相关性。在这些阈值之上，存在一种负相关关系（r=-0.64，P<0.001，女性；r=-0.30，P<0.002，男性）。MHE 对 BW 的依赖性似乎没有明显的上限。肝脂肪变性限制了 MHE。
按 BW 调整 CM 剂量可降低 MHE 对 BW 的依赖性。在 CM 增强 CT 中，较重患者的 BW 与 MHE 之间的关系不存在明显的上限。
