Zabramski Joseph M, Preul Mark C, Debbins Josef, McCusker Daniel J
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, 85013, USA.
Surg Neurol Int. 2012;3:81. doi: 10.4103/2152-7806.99171. Epub 2012 Jul 28.
Exposure of externally programmable shunt-valves (EPS-valves) to magnetic resonance imaging (MRI) may lead to unexpected changes in shunt settings, or affect the ability to reprogram the valve. We undertook this study to examine the effect of exposure to a 3T MRI on a group of widely used EPS-valves.
Evaluations were performed on first generation EPS-valves (those without a locking mechanism to prevent changes in shunt settings by external magnets other than the programmer) and second generation EPS-valves (those with a locking mechanisms). Fifteen new shunt-valves were divided into five groups of three identical valves each, and then exposed to a series of six simulated MRI scans. After each of the exposures, the valves were evaluated to determine if the valve settings had changed, and whether the valves could be reprogrammed. The study produced 18 evaluations for each line of shunt-valves.
Exposure of the first generation EPS-valves to a 3T magnetic field resulted in frequent changes in the valve settings; however, all valves retained their ability to be reprogrammed. Repeated exposure of the second generation EPS-valves has no effect on shunt valve settings, and all valves retained their ability to be interrogated and reprogrammed.
Second generation EPS-valves with locking mechanisms can be safely exposed to repeated 3T MRI systems, without evidence that shunt settings will change. The exposure of the first generation EPS-valves to 3T MRI results in frequent changes in shunt settings that necessitate re-evaluation soon after MRI to avoid complications.
外部可编程分流阀（EPS阀）暴露于磁共振成像（MRI）环境中可能会导致分流设置出现意外变化，或影响对该阀重新编程的能力。我们开展此项研究，以检验暴露于3T MRI环境对一组广泛使用的EPS阀的影响。
对第一代EPS阀（即没有锁定机制以防止除编程器之外的外部磁体改变分流设置的阀门）和第二代EPS阀（即有锁定机制的阀门）进行评估。将15个新的分流阀分成五组，每组三个相同的阀门，然后对其进行一系列六次模拟MRI扫描。每次暴露后，对阀门进行评估，以确定阀门设置是否发生变化，以及阀门是否可以重新编程。该研究对每组分流阀进行了18次评估。
第一代EPS阀暴露于3T磁场会导致阀门设置频繁变化；然而，所有阀门仍保留其重新编程的能力。第二代EPS阀反复暴露对分流阀设置没有影响，所有阀门仍保留其被询问和重新编程的能力。
具有锁定机制的第二代EPS阀可以安全地反复暴露于3T MRI系统，没有证据表明分流设置会发生变化。第一代EPS阀暴露于3T MRI会导致分流设置频繁变化，这就需要在MRI检查后不久重新评估，以避免并发症。
