【摘要】 目的：研究在MRI检查过程中金属医疗植入物引起的机体吸收比（SAR）变化导致的局部升温效应。方法：以数字人影像数据集为基础，通过数据分割和后处理构建了身体上半身半精细化几何模型。最后将几何模型导入到COMSOL中，并搭建3T磁共振线圈，设定工作频率（128 MHz），分析金属医疗植入物对人体组织和植入介质的SAR与温度变化。结果：通过对比不同组织情况下金属医疗植入物植入前后的变化情况发现，金属植入物植入固定后的SAR与温度都是未植入前的3倍，且主要集中在金属医疗植入物区域。结论：在MRI检查中，金属植入物会造成机体中植入物附近SAR局部升高，从而在植入物周围出现升温效应，长时间扫描会对机体产生一定的损伤。更多还原

【Abstract】 Objective To analyze the local temperature rise caused by changes in the specific absorption ratio(SAR) of human body due to metal implant during magnetic resonance imaging. Methods On the basis of the digital human image dataset, a semi-refined geometric model of the upper part of human body was constructed through data segmentation and postprocessing. The geometric model was imported into COMSOL, and a 3T magnetic resonance coil was built and the operating frequency was set at 128 MHz for analyzing the effect of metal implant on SAR and temperature changes. Results Through the comparison of the changes in SAR and temperature of different tissues before and after implantation, it was found that after implantation, SAR and temperature were 3 times higher than those before implantation, and that the changes mainly occurred around the metal implant. Conclusion In magnetic resonance imaging, metal implant can cause local rise of SAR near the implant in human body, which results in temperature rise around the implant, suggesting that long-term scanning will cause certain damages to human body.更多还原