2017年7月28日，澳大利亚治疗产品管理局（TGA）评估了含钆对比剂（GBCA）的最新信息，告知消费者和医务人员在磁共振成像扫描过程中使用GBCA后，少量钆可能会沉积在脑中。目前尚未确定大脑中钆沉积的有害影响，但TGA正在与这些产品的生产企业合作，修改产品安全性信息。

GBCA注射到患者的静脉中，可以增强内脏器官、血管和组织的磁共振成像扫描质量。磁共振成像扫描可帮助医务人员诊断疾病状况。GBCA有两种类型：线型和环型。已发表的研究发现，与环型GBCA相比，线型GBCA可能会在大脑中产生更多的钆沉积。TGA将继续监测上述风险，必要时采取进一步措施。

TGA告之患者和医务人员，钆在脑中沉积仅与磁共振成像扫描中使用的GBCA有关，不涉及用于其他成像程序的其他类型的对比剂。GBCA的产品信息中曾提示钆“不会穿过完整的血脑屏障”，在某些情况下，钆不会在正常脑组织中蓄积。现在越来越多的证据表明这可能发生。

虽然目前尚未发现大脑中钆沉积的有害影响，但TGA和生产企业正在更新产品信息，并建议审慎使用GBCA，尤其是线型GBCA。TGA建议在必须使用GBCA的情况下，应使用最低有效剂量，并谨慎选择GBCA种类。TGA还建议除非临床必须，应避免重复使用这些对比剂进行扫描。

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本文摘自《药物警戒快讯》 第8期(总第172期)