BACKGROUND Catheter designs incorporating metallic braiding have high torque control and kink resistance compared with unbraided alternatives. However, metallic segments longer than a quarter wavelength (~ 12 cm for 1.5 T scanner) are prone to radiofrequency (RF) induced heating during cardiovascular magnetic resonance (CMR) catheterization. We designed a braid-reinforced catheter with interrupted metallic segments to mitigate RF-induced heating yet retain expected mechanical properties for CMR catheterization. METHODS We constructed metal wire braided 6 Fr catheter shaft subassemblies using electrically insulated stainless-steel wires and off-the-shelf biocompatible polymers. The braiding was segmented, in-situ, using lasers to create non-resonant wire lengths. We compared the heating and mechanical performance of segmented- with un-segmented- metal braided catheter shaft subassemblies. RESULTS The braiding segmentation procedure did not significantly alter the structural integrity of catheter subassemblies, torque response, push-ability, or kink resistance compared with non-segmented controls. Segmentation shortened the electrical length of individually insulated metallic braids, and therefore inhibited resonance during CMR RF excitation. RF-induced heating was reduced below 2 °C under expected use conditions in vitro. CONCLUSION We describe a simple modification to the manufacture of metallic braided catheters that will allow CMR catheterization without RF-induced heating under contemporary scanning conditions at 1.5 T. The proposed segmentation pattern largely preserves braid structure and mechanical integrity while interrupting electrical resonance. This inexpensive design may be applicable to both diagnostic and interventional catheters and will help to enable a range of interventional procedures using real time CMR.

中文翻译：

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1.5 T时用于介入性CMR的心血管磁共振（CMR）安全金属编织导管设计：不受射频感应加热的影响，并保留了机械性能。

背景技术与无编织替代物相比，结合有金属编织物的导管设计具有高扭矩控制和抗扭结性。但是，长于四分之一波长（对于1.5 T扫描仪约为12厘米）的金属段在心血管磁共振（CMR）导管插入过程中容易受到射频（RF）诱导的加热。我们设计了编织增强导管，其金属段间断，以减轻RF引起的加热，同时保留CMR导管插入术的预期机械性能。方法我们使用电绝缘的不锈钢丝和现成的生物相容性聚合物构建了金属丝编织的6 Fr导管轴组件。使用激光在原位对编织物进行分段，以产生非谐振的导线长度。我们比较了分段式和非分段式金属编织导管轴组件的加热和机械性能。结果与非分段对照相比，编织分割程序并未显着改变导管子组件的结构完整性，扭矩响应，推动能力或抗扭结性。分段缩短了单独绝缘的金属编织层的电气长度，因此抑制了CMR RF激励期间的谐振。在预期的体外使用条件下，RF诱导的加热降低到2°C以下。结论我们描述了对金属编织导管制造的简单修改，该修改将允许在1.5 T的现代扫描条件下进行CMR导管插入而无需RF感应加热。所提出的分割图案在中断电共振的同时很大程度上保留了编织结构和机械完整性。这种廉价的设计可能适用于诊断导管和介入导管，并且将有助于实现使用实时CMR的一系列介入程序。