Gustave Roussy Institute, Villejuif, France.
Cardiovasc Intervent Radiol. 2012 Aug;35(4):898-905. doi: 10.1007/s00270-011-0278-8. Epub 2011 Sep 27.
This study was designed to evaluate the accuracy and safety of electromagnetic needle tracking for sonographically guided percutaneous liver biopsies.
We performed 23 consecutive ultrasound-guided liver biopsies for liver nodules with an electromagnetic tracking of the needle. A sensor placed at the tip of a sterile stylet (18G) inserted in a coaxial guiding trocar (16G) used for biopsy was localized in real time relative to the ultrasound imaging plane, thanks to an electromagnetic transmitter and two sensors on the ultrasound probe. This allows for electronic display of the needle tip location and the future needle path overlaid on the real-time ultrasound image. Distance between needle tip position and its electronic display, number of needle punctures, number of needle pull backs for redirection, technical success (needle positioned in the target), diagnostic success (correct histopathology result), procedure time, and complication were evaluated according to lesion sizes, depth and location, operator experience, and "in-plane" or "out-of-plane" needle approach.
Electronic display was always within 2 mm from the real position of the needle tip. The technical success rate was 100%. A single needle puncture without repuncture was used in all patients. Pull backs were necessary in six patients (26%) to obtain correct needle placement. The overall diagnostic success rate was 91%. The overall true-positive, true-negative, false-negative, and failure rates of the biopsy were 100% (19/19) 100% (2/2), 0% (0/23), and 9% (2/23). The median total procedure time from the skin puncture to the needle in the target was 30 sec (from 5-60 s). Lesion depth and localizations, operator experience, in-plane or out-of-plane approach did not affect significantly the technical, diagnostic success, or procedure time. Even when the tumor size decreased, the procedure time did not increase.
Electromagnetic-tracked biopsy is accurate to determine needle tip position and allows fast and accurate needle placement in targeted liver nodules.
本研究旨在评估电磁针跟踪技术在超声引导下经皮肝活检中的准确性和安全性。
我们对 23 个经超声引导的肝结节进行了连续的电磁针跟踪肝活检。将一个位于无菌引导针（18G）尖端的传感器插入同轴引导套管针（16G）中，用于活检，通过电磁发射器和超声探头上的两个传感器实时定位在超声成像平面上。这允许电子显示针尖位置和未来的针路径叠加在实时超声图像上。根据病变大小、深度和位置、操作者经验以及“平面内”或“平面外”进针方法，评估针尖位置与电子显示之间的距离、进针次数、重新进针以调整方向的次数、技术成功率（针位于目标部位）、诊断成功率（正确的组织病理学结果）、操作时间和并发症。
电子显示始终与针尖的实际位置相差 2 毫米以内。技术成功率为 100%。所有患者均采用单次进针，无需再次进针。六名患者（26%）需要回拉以获得正确的针位。总的诊断成功率为 91%。活检的总体真阳性、真阴性、假阴性和失败率分别为 100%（19/19）、100%（2/2）、0%（0/23）和 9%（2/23）。从皮肤穿刺到目标的总操作时间中位数为 30 秒（5-60 秒）。病变深度和位置、操作者经验、平面内或平面外进针方法均未显著影响技术、诊断成功率或操作时间。即使肿瘤大小减小，操作时间也不会增加。
电磁跟踪活检能够准确确定针尖位置，并允许快速准确地将针放置在靶向肝结节中。
