An American Heart Association Scientific Statement：
美国心脏协会科学声明：
Coronary Artery and Peripheral Vascular Stents
冠状动脉和外周血管支架
Most coronary and peripheral vascular stents that have been tested have been labeled as “MR safe”； the remainder have been labeled as “MR conditional.”1 Tested coronary artery stents (including tested drug-eluting coronary stents) that are nonferromagnetic (all currently used coronary stents) can be safely scanned at 3 T or less any time after implantation. MR examination at 3T in patients with peripheral stents that are nonferromagnetic can be performed immediately after implantation.The timing of MR examination at 3T in patients with peripheral stents that are weakly ferromagnetic should be determined on a case-by-case basis. For cases in which there is a clear potential clinical benefit of scanning in the days to weeks after implantation, the benefits of the MR examination will likely outweigh the risks of the examination, and MR examination should generally be performed. In patients with chronic conditions in which it makes little difference whether the scan is performed at a given time or weeks later, it may be prudent to defer MR examination until 6 weeks after device implantation.
经过测试的大多数冠状动脉和外周血管支架，说明书标注为“磁共振安全”；其余标注为“磁共振条件性安全”。经过测试的非铁磁性冠状动脉支架（包括药物洗脱支架）（所有当前使用的冠状动脉支架均为非铁磁性），可以在植入后的任何时间、在≤3T场强中安全扫描。非铁磁性外周血管支架可在植入后立即接受≤3T磁共振检查。弱磁性外周血管支架接受≤3T磁共振检查的时间应根据具体情况而定。 对于在植入后数天至数周内有明显潜在临床益处的扫描，磁共振检查的好处可能会超过检查的风险，通常应进行MR检查。对于慢性疾病患者，如果在特定时间或数周后扫描没有多大差异，出于谨慎可以把磁共振检查推迟到装置植入后6周。
Aortic Stent Grafts
主动脉覆膜支架
Most aortic stent grafts that have been tested have been labeled as “MR safe”； the Zenith AAA endovascular graft stent has been labeled as “MR unsafe.”Patients with stent grafts made from nonferromagnetic materials may be scanned immediately after implantation at 3 T or less. The timing of
MR examination at 3T or less in patients with aortic stent grafts that are weakly ferromagnetic should be weighed on a case-by-case basis. For cases in which there is a clear potential clinical benefit of scanning in the days to weeks after implantation, the benefits of the MR examination will likely outweigh the risks of the examination, and MR examination should generally be performed. In patients with chronic conditions in which it makes little difference whether the scan is performed at a given time or weeks later, it may be prudent to defer MR examination until 6 weeks after device implantation.
经过测试的大多数主动脉覆膜支架，说明书标注为“磁共振安全”；Zenith AAA血管内覆膜支架，说明书标注为“磁共振不安全”。非铁磁性覆膜支架可在植入后立即接受≤3T磁共振检查。弱磁性主动脉覆膜支架接受≤3T磁共振检查的时间应根据具体情况而定。对于在植入后数天至数周内有明显潜在临床益处的扫描，磁共振检查的好处可能会超过检查的风险，通常应进行MR检查。对于慢性疾病患者，如果在特定时间或数周后扫描没有多大差异，出于谨慎可以把磁共振检查推迟到装置植入后6周。
Prosthetic Heart Valves, Annuloplasty Rings, and Sternal Suture Wires
人工心脏瓣膜、瓣膜成形环、胸骨缝合线
The majority of prosthetic heart valves and annuloplasty rings that have been tested have been labeled as “MR safe”； the remainder of heart valves and rings that have been tested have been labeled as “MR conditional.” On the basis of the above studies and findings, the presence of a prosthetic heart valve or annuloplasty ring that has been formally evaluated for MR safety should not be considered a contraindication to an MR examination at 3 T or less (and possibly even 4.7 T in some cases) any time after implantation. MR examination of patients with sternal wires is generally considered to be safe.
经过测试的大多数人工心脏瓣膜和瓣膜成形环，说明书标注为“磁共振安全”；其余标注为“磁共振条件性安全”。正式通过磁共振安全性评估的人工心脏瓣膜或瓣膜成形环，在植入后的任何时间都不应被认为是≤3T磁共振检查（在某些情况下甚至可达到4.7T）的禁忌证。 通常认为有胸骨缝合线的患者磁共振检查安全。
Cardiac Closure and Occluder Devices
心脏封堵器
The majority of cardiac closure and occluder devices that have been tested have been labeled as “MR safe”； several that have been tested are labeled as “MR conditional.” Patients with nonferromagnetic cardiac closure and occluder devices may undergo MR procedures at any time after implantation.
The timing of MR examination at 3 T or less in patients with cardiac closure or occluder devices that are weakly ferromagnetic should be weighed on a case-by-case basis. For cases for which there is a clear potential clinical benefit of scanning in the days to weeks after implantation, the benefits of the MR examination will likely outweigh the risks of the examination, and MR examination should generally be performed. In patients with chronic conditions in which it makes little difference whether the scan is performed at a given time or weeks later, it may be prudent to defer MR examination until 6 weeks after device implantation.
经过测试的大多数心脏封堵器，说明书标注为“磁共振安全”；其余标注为“磁共振条件性安全”。有非铁磁性心脏封堵器的患者，可以在植入后的任何时间接受磁共振扫描。弱磁性心脏封堵器接受≤3T磁共振检查的时间应根据具体情况而定。对于在植入后数天至数周内有明显潜在临床益处的扫描，磁共振检查的好处可能会超过检查的风险，通常应进行磁共振检查。对于慢性疾病患者，如果在特定时间或数周后扫描没有多大差异，出于谨慎可以把磁共振检查推迟到装置植入后6周。
Inferior Vena Cava Filters
下腔静脉滤器
Most IVC filters that have been tested have been labeled as“MR safe”； the remainder of IVC filters that have been tested are classified as “MR conditional.” Patients who have been treated with nonferromagnetic IVC filters can undergo MR examination any time after filter implantation. In patients who have been treated with a weakly ferromagnetic IVC filter (Gianturco bird nest IVC filter [Cook], stainless steel Greenfield vena cava filter [Boston Scientific]), it is advised that the patient wait at least 6 weeks before undergoing an MR examination (because these older devices initially may not be anchored as firmly in place as other devices discussed in the present report), unless there is a strong clinical indication to perform the MR examination sooner after implantation, and as long as there is no reason to suspect that the device is not positioned properly or that it is not firmly in place. Most studies of IVC filters have generally been conducted at 1.5 T or less, although many IVC filters have now been evaluated at 3 T and deemed acceptable for MR examination
经过测试的大多数下腔静脉滤器，说明书标注为“磁共振安全”；其余标注为“磁共振条件性安全”。有非铁磁性下腔静脉滤器的患者，可以在植入后的任何时间接受磁共振扫描。有弱磁性下腔静脉滤器（Gianturco bird nest下腔静脉滤器[Cook公司]、Greenfield不锈钢腔静脉滤器[Boston Scientific公司]）的患者，建议把磁共振检查推迟到装置植入后至少6周（因为这些老款装置安装未必像其他装置那样牢固就位），除非有强烈临床指征要求在植入后很快接受磁共振检查并且没有理由怀疑装置位置不正或固定不牢固。大多数下腔静脉滤器的研究是在≤1.5T条件下完成，有一些是在3T条件下完成并且被认为可接受。
Embolization Coils
栓塞弹簧圈
Most embolization coils that have been tested have been labeled as “MR safe”； the remainder that have been tested have been labeled as “MR conditional.”Patients who have been treated with nonferromagnetic embolization coils can undergo MR examination any time after coil implantation. The timing of MR examination at 3 T or less in patients with embolization coils that are weakly ferromagnetic should be weighed on a case-by-case basis. For cases in which there is a clear potential clinical benefit of scanning in the days to weeks after implantation, the benefits of the MR examination will likely outweigh the risks of the examination, and MR examination should generally be performed. In patients with chronic conditions in which it makes little difference whether the scan is performed at a given time or weeks later, it may be prudent to defer MR examination until 6 weeks after device implantation. Patients with tested coils may undergo MR examination at up to 3 T, according to the conditions under which they were tested.
经过测试的大多数栓塞弹簧圈，说明书标注为“磁共振安全”；其余标注为“磁共振条件性安全”。有非铁磁性栓塞弹簧圈的患者，可以在植入后的任何时间接受磁共振扫描。弱磁性栓塞弹簧圈接受≤3T磁共振检查的时间应根据具体情况而定。对于在植入后数天至数周内有明显潜在临床益处的扫描，磁共振检查的好处可能会超过检查的风险，通常应进行MR检查。对于慢性疾病患者，如果在特定时间或数周后扫描没有多大差异，出于谨慎可以把磁共振检查推迟到装置植入后6周。有经过测试的栓塞弹簧圈的患者，根据测试条件，可以接受高达3T的磁共振检查。
Loop Recorder (Event Monitor)
循环记录器（事件监视器）
The Reveal Plus ILR has been labeled as “MR conditional.” Patients with a Reveal Plus ILR can undergo MR examination any time after implantation, provided there is no reason to believe the device is not well implanted. Because of the theoretical risk of electromagnetic fields adversely affecting data stored by the device, all stored data should be downloaded before scanning. Because this device contains ferromagnetic components, the strong magnetic fields associated with the MR system can create sufficient magnetic field interactions for the Reveal Plus ILR such that the patient may feel slight movement of this device. Although this does not represent a safety hazard, the patient should be informed of this possibility to avoid undue concern.
Reveal Plus循环记录器，说明书标注为“磁共振安全”。有Reveal Plus循环记录器的患者，可以在植入后的任何时间接受磁共振扫描，前提是没有理由相信该装置植入不良。 由于理论上电磁场对设备存储的数据有产生不利影响的风险，所有存储的数据应在磁共振扫描前下载。由于该装置含有铁磁性部件，磁共振产生的强磁场可以与Reveal Plus ILR产生足够的相互作用，使得患者可能会感觉到该装置轻微活动。尽管这并不代表安全隐患，也应该告知患者这种可能性，以消除不必要的担心。
Hemodynamic Monitoring and Temporary Pacing Devices
血流动力学监测和临时起搏装置
Those few catheters that contain conducting wires and those few temporary transvenous pacing wires that have been tested have been labeled as “MR unsafe.” Patients with pulmonary artery hemodynamic monitoring/thermodilution catheters (such as the Swan-Ganz catheter) and similar catheters that have conductive wires or similar components should not undergo MR examinations because of the possible associated risks, unless in vivo testing provides labeling information or instructions for use that permit examinations to be performed safely. Patients with nonferromagnetic pulmonary artery catheters that contain no electrically conductive pathways in the catheter may undergo MR examination； however, it must be emphasized that such conditions must be verified before such patients undergo MR examination. Patients with retained temporary epicardial pacing wires are believed to be able to safely undergo MR procedures, and patients do not need to be routinely screened for the presence of such wires before scanning. Because of the possible risks involved with temporary-pacemaker external pulse generators, such generators should not be introduced into the MR environment.
包含导线的少数导线和已经测试的少数临时静脉起搏线，说明书标注为“磁共振不安全”。有肺动脉血流动力学监测/热稀释导管（如Swan-Ganz导管）和类似导管的患者，由于存在导线或类似组件，可能引起风险，不应进行磁共振检查，除非体内测试提供可以安全检查的标签信息或使用说明。有导管中不含导电通路的非磁性肺动脉导管的患者可进行磁共振检查；然而，必须强调，这种条件安全性必须在之前得到验证。保留临时心外膜起搏线的患者能够安全地接受MR检查，扫描前不需要常规筛查这种电线的存在。由于临时起搏器外部脉冲发生器可能涉及到风险，因此不应将这种发生器带入磁共振环境。
Although temporary transvenous lead heating might be minimized or avoided by scanning anatomic regions above (eg, head/brain) or below (eg, lower extremities) cardiac pacing leads, scanning of patients with temporary transvenous pacing leads (without the generator) is not recommended. Furthermore, because the harsh electromagnetic environment associated with the MR system can alter the operation of an external pulse generator or damage it, it may not be possible to reliably pace the patient during the MR examination, which makes the issue of scanning a patient with a temporary transvenous lead irrelevant in most cases.
尽管扫描心脏起搏导联以上（如头/脑）或以下（如下肢）解剖区域可能会最小化或避免临时静脉导联发热，但不建议有临时静脉起搏导联（无发生器）的患者接受磁共振扫描。并且，由于磁共振系统的恶劣电磁环境可以改变外部脉冲发生器的操作或损坏外部脉冲发生器，所以在磁共振检查期间可能无法可靠地对患者进行起搏，从而使给有临时静脉导联的患者做磁共振扫描变得不太可能。
Permanent Cardiac Pacemakers and Implantable Cardioverter Defibrillators
永久心脏起搏器和植入式心律转复除颤器
A pacemaker or ICD should still be considered a strong relative contraindication to routine MR examination, which is therefore discouraged. Patients who have a pacemaker or ICD should not undergo an MR study if an alternative diagnostic test is available, and MR imaging should only be considered in cases in which the potential benefit to the patient clearly outweighs the risks to the patient. Recommendations regarding the scanning of patients with permanent pacemakers and ICDs can be expected to evolve over time as more studies become available.
起搏器或植入式心律转复除颤器仍然被认为是常规磁共振检查的强有力的相对禁忌证，因此不鼓励。具有心脏起搏器或植入式心律转复除颤器的患者如果有替代性诊断检查，则不应进行磁共振检查。随着越来越多的研究发表，关于有永久起搏器和植入式心律转复除颤器患者的磁共振扫描建议可以随着时间的推移而发展。
Those pacemakers that have been tested have been labeled as “MR unsafe.”At present, MR examination of non–pacemaker-dependent patients is discouraged and should only be considered in cases in which there is a strong clinical indication, in which the benefits clearly outweigh the risks, and then according to the criteria. There are few current data on the performance of MR examination of pacemaker-dependent patients, and MR examination of pacemaker-dependent patients should not be performed unless there are highly compelling circumstances in which the benefits clearly outweigh the risks and then according to the criteria. MR examination of patients with ICDs should not be performed unless there are highly compelling circumstances in which the benefits clearly outweigh the risks and then according to the criteria. Although 1 study discussed above found that ICDs manufactured after 2000 may be more resistant to changes in function during MR examination, this finding should not be taken as a “green light” to routinely scan patients with such ICDs. Fractured leads may pose a particularly high risk of thermal injury, and MR examination should not be performed in patients with pacemakers or ICDs with known lead fractures.
经过测试的起搏器，说明书标注为“磁共振不安全”。目前，不鼓励对非起搏器依赖的患者进行磁共振检查，只有在临床指征强烈、获益明显超过风险并符合标准的情况下才能考虑。目前关于起搏器依赖患者磁共振检查的数据很少。起搏器依赖患者不应做磁共振检查，除非有非常强烈的必要性、获益明显超过风险并符合标准。植入式心律转复除颤器患者不应做磁共振检查，除非有非常强烈的必要性、获益明显超过风险并符合标准。尽管一项研究发现，2000年以后制造的植入式心律转复除颤器在磁共振检查时更稳定，也不能给有这种植入式心律转复除颤器的患者常规磁共振扫描。断裂导联可能造成特别高的热损伤风险，不应给已知有导联断裂的心脏起搏器或植入式心律转复除颤器的患者进行磁共振检查。
Retained Transvenous Pacemaker and Defibrillator Leads
保留静脉起搏器和除颤器引线
The patients with retained transvenous pacemakers or ICD leads be approached similarly to those with pacemakers or ICDs, as outlined above. MR examination of patients with retained transvenous leads is discouraged, and MR examination should only be considered in centers with expertise in MR and electrophysiology, and only in cases in which there is a strong clinical indication. MR examination should not be performed in patients with known retained transvenous leads that have fractures.
有保留静脉起搏器或植入式心律转复除颤器导联的患者，与起搏器或植入式心律转复除颤器的处理方法类似，如上所述。不鼓励有保留静脉导联的患者接受磁共振检查，其磁共振检查只能在具有磁共振和电生理学专业知识的中心考虑，并且只有在具备强烈临床指征的情况下进行。在已知保留静脉导管断裂的患者中，磁共振检查不应进行。
Hemodynamic Support Devices
血流动力学支持装置
Hemodynamic support devices, including intra-aortic balloon pumps, right ventricular assist devices, and left ventricular assist devices, are complex devices with variable degrees of ferromagnetic materials, moving parts, and electrical components.Although formal evaluation of these devices in regard to MR safety has not been conducted, it is believed that these devices should be considered absolute contraindications to MR examination, particularly given that most hemodynamic support systems involve equipment likely to be affected by the electromagnetic fields used during MR imaging.
血流动力学支持装置，包括主动脉内球囊泵、右心室辅助装置和左心室辅助装置，是含有具有不同程度铁磁性材料、活动部件和电气部件的复杂装置。虽然这些装置磁共振安全性的正式评估尚未进行，但相信这些装置应被视为磁共振检查的绝对禁忌证，特别是因为大多数血流动力学支持系统含有可能受到磁共振电磁场影响的部件。
参考文献：
Levine GN, Gomes AS, Arai AE, et al. Safety of magnetic resonance imaging in patients with cardiovascular devices: an American Heart Association scientific statement from the Committee on Diagnostic and Interventional Cardiac Catheterization, Council on Clinical Cardiology, and the Council on Cardiovascular Radiology and Intervention: endorsed by the American College of Cardiology Foundation, the North American Society for Cardiac Imaging, and the Society for Cardiovascular Magnetic Resonance. Circulation, 2007,116(24):2878-2891.
联系客服
