1.1 本测试方法包括在磁共振成像（MRI）期间测量模型内被动医疗植入物上或附近的射频感应加热。该测试方法没有规定被认为对患者安全的加热水平，而是依赖于用户定义自己的验收标准。 1.2 本试验方法不解决其他可能的安全问题，包括但不限于:磁感应位移、磁感应扭矩、图像伪影、噪声、组织加热、设备之间的相互作用以及设备和MR系统的功能性问题。 1.3 射频引起的温升量( ∆T )对于给定的入射电场，电场将取决于射频频率，射频频率取决于磁流变系统的静态磁场强度。虽然本测试方法的重点是1.5特斯拉（T）或3 T磁共振系统，但 ∆T 对于MR系统中的植入物，可以通过对本文所述方法的适当修改来评估其他静态磁场强度或磁体设计。 1.4 该测试方法假设测试在完全位于身体内部的设备上进行。测试具有其他植入条件的设备（例如。 g、 、外固定装置、经皮穿刺针、导管或栓系装置（如消融探头）不在本标准范围内；对于此类装置，可能需要修改本试验方法。 注1: 任何导电植入设备引起的射频加热可能会受到附近存在的其他金属或导电设备的影响。 1.5 本测试方法适用于几种可能的射频暴露系统，包括体积射频发射线圈。暴露系统需要在规定的不确定性范围内，根据被测试植入物的局部背景射频暴露，对其进行适当表征。 1.6 以国际单位制表示的数值应视为标准值。 1.7 在所有方向上部署尺寸小于2 cm的设备可能不需要进行射频感应加热测试，因为它预计会产生 ∆T 在1.5 T/64 MHz或3 T/128 MHz频率下暴露1小时，温度低于2°C ( 1. , 2. ) 2. 和ANSI/AAMI/ISO 14708-3:2017）。当装置的多个复制品（例如，多个锚）植入装置的3 cm范围内时，该条件无效。 注2: 上述数值来自现有数据和文献。 建议使用3厘米的距离，以避免与其他相邻设备发生任何射频耦合。 1.8 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本试验方法描述了用于评估 ∆T 与MR过程中的射频功率沉积有关，涉及被动植入物的特定射频辐照频率。该方法允许表征植入物的加热倾向，而不是预测患者在特定MR过程中的加热。结果可作为计算模型的输入，用于估计 ∆T 因为患者体内有植入物。测试结果和计算模型结果的组合可用于帮助评估MR检查期间植入物患者的安全性。

1.1 This test method covers measurement of radio frequency (RF)-induced heating on or near a passive medical implant within a phantom during magnetic resonance imaging (MRI). The test method does not specify levels of heating considered to be safe to the patient and relies on users to define their own acceptance criteria. 1.2 This test method does not address other possible safety issues which include, but are not limited to: issues of magnetically-induced displacement, magnetically-induced torque, image artifact, acoustic noise, tissue heating, interaction among devices, and the functionality of the device and the MR system. 1.3 The amount of RF-induced temperature rise ( ∆T ) for a given incident electric field will depend on the RF frequency, which is dependent on the static magnetic field strength of the MR system. While the focus in this test method is on 1.5 tesla (T) or 3 T MR systems, the ∆T for an implant in MR systems of other static magnetic field strengths or magnet designs can be evaluated by suitable modification of the method described herein. 1.4 This test method assumes that testing is done on devices that will be entirely inside the body. Testing for devices with other implantation conditions (e.g., external fixation devices, percutaneous needles, catheters or tethered devices such as ablation probes) is beyond the scope of this standard; for such devices, modifications of this test method may be necessary. Note 1: RF-heating induced by any electrically conductive implanted device may be impacted by the presence of other metallic or otherwise electrically conductive devices present nearby. 1.5 This test method is written for several possible RF exposure systems, including Volume RF transmit coils. The exposure system needs to be properly characterized, within the stated uncertainties, in term of local background RF exposure for the implants which are tested. 1.6 The values stated in SI units are to be regarded as standard. 1.7 A device with deployed dimensions of less than 2 cm in all directions may not need to be tested with respect to RF-induced heating, as it is expected to generate ∆T of less than 2°C over 1 h of exposure at 1.5 T/64-MHz or 3 T/128-MHz frequencies ( 1 , 2 ) 2 and ANSI/AAMI/ISO 14708-3:2017). This condition is not valid when multiple replicas of the device (e.g., multiple anchors) are implanted within 3 cm of the device. Note 2: The above values were derived from existing data and literature. The 3 cm distance is recommended to avoid any RF coupling with other neighboring devices. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This test method describes a test procedure for evaluating the ∆T associated with RF power deposition during an MR procedure, involving a specific frequency of RF irradiation of a passive implant. The method allows characterization of the heating propensity of an implant rather than the prediction of heating during a specific MR procedure in a patient. The results may be used as an input to a computational model for estimating ∆T due to the presence of that implant in a patient. The combination of the test results and the computational model results may then be used to help assess the safety of a patient with the implant during an MR examination.