目标:在过去的十年中,7T时的临床MRI研究数量急剧增加.由于7T只能获得有关植入物/纹身安全性的有限信息,许多中心要么保守地排除所有有植入物/纹身的受试者,要么已经开始对选定的植入物进行专门的测试。这项工作展示了我们在过去七年半中对7T植入物/纹身的志愿者进行成像的经验。
方法:对1796份问卷进行回顾性分析,以确定在7T时具有植入物/纹身成像的受试者。用于检查的本地发射/接收RF线圈的类型,成像序列,采集时间,并记录了植入物/纹身的类型及其相对于视野的位置。这些受试者经过由MR安全和物理学的三名专家组成的内部安全小组的仔细考虑后接受了检查。
结果:之前没有受试者报告热或力的感觉,during,或者在考试之后。没有人表示与植入物/纹身有关的任何不适。据报道,52%的牙科植入物受试者存在伪影;所有伪影都仅限于口腔区域,并且不影响脑实质的图像质量。
结论:我们在7T时的初步经验表明,严格排斥带有纹身和/或植入物的受试者是不合理的。在收集大量安全信息并评估详细的暴露情况(RF线圈/植入物的类型和位置)之后,可以有条件地在仔细选择的受试者中进行成像。在有纹身的评估对象中,没有报道暴露于7TMRI的副作用。
OBJECTIVE: Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years.
METHODS: 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics.
RESULTS: None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52% of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma.
CONCLUSIONS: Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.