国产封堵器植入后行3.0T磁共振检查的安全性及对影像的影响

Safety of China-made occluders and the influence on MRI images under post-implantation 3.0T MR scan

目的探讨几种常用国产封堵器植入后行3.0T MR检查时的安全性,及封堵器对MRI图像质量的影响。方法将封堵器悬挂于3.0T磁场中测量其偏转角度,再植入离体猪心内,行3.0T MR扫描,观察封堵器在扫描前后有无变形、移位,并分析图像、判断封堵器对图像质量有无影响。结果所有封堵器在磁场中均产生一定的偏转角度,均远<45°(P<0.01)。扫描前后,植入猪心的封堵器无变形或移位。房间隔缺损及动脉导管未闭封堵器盘片边缘轮廓显示较清晰,其轮廓内及周围可见伪影,且越靠近中心伪影越明显;室间隔缺损封堵器轮廓模糊,伪影范围明显大于其直径;总体上,较大的封堵器产生的伪影范围更大;同时植入3个封堵器,相互间图像无干扰。结论 3.0T MR常规扫描不会导致国产封堵器变形或移位,金属封堵器会对其自身及周围心脏结构的观察产生影响,但对心脏其他部位的图像质量无影响。

Objective To explore the safety of several common China-made occluders and their influence on the quality of MR image when the patient underwent a 3.0T MR scan. Methods The occluders were suspended in a magnetic field at a strength of 3.0T to measure their angle of deflection under such environment. 3.0T MR scans were performed on porcine hearts implanted with the occluders to examine if any deformation or displacement had occurred. Images were also analyzed to detect whether the occluders have affected their quality. Results All occluders in the magnetic field had an angle of de- flection less than 45° （P〈0.01）. The occluders implanted into the porcine hearts were neither deformed nor displaced after scanning. The MRI images showed relatively clearer discs for both atrial septal defect （ASD） and patent ductus arteriosus （PDA） occ[uders, while the ventricular septal defect （VSD） occluder had an overa｜[ vague contour. The ASD and PDA oc- cluders had artifacts that spreaded from the center, while the VSD occluder was covered by an artifact larger than the device itself. Occluders bigger in size generally produce more noticeable artifacts. The simultaneous implantation of three occlud- ers did not interfere with the image. Conclusion A 3.0T MR regular scan will not lead to the deformation or displacement of the occluders. While a metal occluder may affect the screening of itself and its adjacent cardiac structure, such influence is not present on the images of other parts of the heart.