Department of Radiology, Nijmegen Medical Centre, Radboud University, Nijmegen, Gelderland 6500 HB, Netherlands.
Med Phys. 2010 Sep;37(9):4744-50. doi: 10.1118/1.3475945.
To introduce a new in-house developed pneumatically controlled magnetic field compatible manipulator as an aid to perform magnetic resonance (MR)-guided biopsies of the prostate.
A pneumatic controlled manipulator with five degrees of freedom constructed of plastic to achieve magnetic field compatibility was developed to guide biopsies. A risk analysis, mechanical tests, and RF safety tests with respect to needle tip heating were performed to assure future patient safety and to meet standard safety requirements for the use in a medical environment. The accuracy of needle positioning with the needle guide manipulator to sample a predefined target was measured in agar phantoms on a 3 T whole body MR system. The in-plane error was used to evaluate the accuracy, which is defined as the orthogonal distance between target and biopsy needle. The time for each step in the biopsy procedure was recorded to evaluate the procedure time. The influence of the insertion angle with respect to the static field of the MR scanner on the needle artifact was investigated.
The risk analyses met patient safety requirements. No RF induced local heating around the needle tip was observed. The average in-plane error in 19 measurements was 3.0 mm (range 0-5.6 mm). The average time needed for manipulation to place the needle guide in the desired position was 5 min (range 3-8 min). Total procedure time was 30 min. The needle artifact size increases with the insertion angle with respect to the static field of the MR scanner.
The new MR compatible manipulator can be used safely for patient care. It showed a high accuracy and short total procedure time, demonstrating great potential to improve the transrectal prostate biopsy procedure.
介绍一种新的内部开发的气动控制磁场兼容操作臂，作为辅助工具，以进行磁共振（MR）引导的前列腺活检。
为了引导活检，开发了一种由塑料制成的具有五个自由度的气动控制操作臂，以实现磁场兼容性。对风险分析、机械测试和针对针尖加热的射频安全性测试进行了测试，以确保未来患者的安全，并满足在医疗环境中使用的标准安全要求。在 3T 全身磁共振系统的琼脂体模上测量了使用针引导操作臂定位针以采样预定义靶标的准确性。使用定义为目标和活检针之间的正交距离的针内误差来评估准确性。记录活检过程中每个步骤的时间，以评估过程时间。研究了相对于磁共振扫描仪静磁场的插入角度对针伪影的影响。
风险分析符合患者安全要求。未观察到针尖周围的射频诱导局部加热。在 19 次测量中的平均平面内误差为 3.0 毫米（范围 0-5.6 毫米）。将针引导器操纵到所需位置的平均时间为 5 分钟（范围 3-8 分钟）。总手术时间为 30 分钟。随着相对于磁共振扫描仪静磁场的插入角度的增加，针伪影的大小增加。
新的磁共振兼容操作臂可安全地用于患者护理。它显示出高精度和短的总手术时间，显示出改善经直肠前列腺活检过程的巨大潜力。
