Gadolinium Retention Estimation Tool

This Excel file provides a tool for estimating gadolinium (Gd) retention in patients based on the time (in months) between MRI gadolinium contrast media (Gd-CM) administration and urine sample collection. Users can input spot urine and Chelate-Evoked Metal Excretion Test (CEMET) urine Gd concentrations in µg/g creatinine along the time lapse after Gd-CM exposure in months. The results are then plotted into norm-regression curves with ±95% confidence intervals (CI) to provide an estimate of the lag-time-specific Gd retention.The regression curves are based on data from 54 patient samples. Spot urine samples were collected in the morning while fasting. Subsequently, a standard intravenous infusion of 600 mg glutathione, 1.9 g Na-Ca-EDTA, and 250 mg DMPS was administered, with CEMET urine collected two hours after infusion initiation. This combination of chelation agents enhances sensitivity and broadens the range of metals captured by CEMET.Na-Ca-EDTA effectively binds and promotes the urinary excretion of gadolinium, making it a viable alternative to Zn-DTPA. The tool generates two distinct regression curves: one for short- to medium-term gadolinium retention (&lt;24 months, in sheet 1) and another for long-term retention (2–10 years, in sheet 2), reflecting different slope trends over time.Sheet 3 includes a Python script that enables users to generate norm diagrams and aggregate patient data. This script can be customized to adjust norm diagrams and 95% CIs for specific research questions or patient subsets, such as those differentiated by renal function, lifetime gadolinium exposure, or specific Gd-CM types or brands.While this tool estimates gadolinium retention in tissues after defined intervals following Gd-CM administration, elevated retention values do not necessarily correlate with clinical symptoms. Patients with typical retention may still exhibit symptoms, while those with elevated retention might remain asymptomatic.Increased sensitivity to gadolinium and related pathologies seems to involve autoimmune mechanisms or predisposing factors, such as decreased metal tolerance or increased pre-exam metal exposure, which are not directly linked to gadolinium concentrations in blood or urine. Therefore, this tool is valuable for estimating individual gadolinium retention after Gd-CM exposure but is not intended to determine toxicity levels.本Excel文件提供了一款工具，可基于磁共振成像钆对比剂（MRI gadolinium contrast media, Gd-CM）给药与尿液样本采集之间的间隔时长（单位：月），估算患者体内的钆（gadolinium, Gd）潴留量。用户可输入钆对比剂给药后间隔时长（单位：月）对应的随机尿样与螯合剂诱导金属排泄试验（Chelate-Evoked Metal Excretion Test, CEMET）尿液样本的钆浓度，单位为µg/g肌酐。随后将结果绘制成带有±95%置信区间（confidence intervals, CI）的正态回归曲线，以估算特定滞后时长下的钆潴留量。 该回归曲线基于54份患者样本的数据。随机尿样于晨起空腹状态下采集，随后予以标准静脉输注：600mg谷胱甘肽、1.9g乙二胺四乙酸钙钠（Na-Ca-EDTA）与250mg二巯基丙磺酸钠（DMPS），并于输注开始后2小时采集CEMET尿液样本。该螯合剂组合可提升检测灵敏度，并扩大CEMET所能捕获的金属范围。乙二胺四乙酸钙钠（Na-Ca-EDTA）可有效结合钆并促进其经尿液排泄，是锌二乙三胺五乙酸（Zn-DTPA）的可行替代方案。 本工具可生成两条独立的回归曲线：一条用于估算中短期钆潴留（时长<24个月，位于工作表1），另一条用于估算长期钆潴留（时长2~10年，位于工作表2），二者反映出随时间变化的不同斜率趋势。工作表3包含一段Python脚本，支持用户生成正态分布图并汇总患者数据。该脚本可自定义调整，以适配特定研究需求或患者亚组的正态分布图与95%置信区间，例如按肾功能、终身钆暴露量、特定钆对比剂类型或品牌划分的亚组。 尽管本工具可估算钆对比剂给药后特定间隔时长下的组织钆潴留量，但潴留量升高并不一定与临床症状相关：表现出典型潴留水平的患者仍可能出现症状，而潴留量升高的患者也可能无任何症状。机体对钆及相关病症的易感性升高，似乎与自身免疫机制或易感因素有关，例如金属耐受度降低或检查前金属暴露量增加，而这些因素与血液或尿液中的钆浓度并无直接关联。因此，本工具可用于估算钆对比剂暴露后个体的钆潴留量，但并非用于判定毒性水平。