O'Gorman Ruth L, Jarosz Josef M, Samuel Michael, Clough Chris, Selway Richard P, Ashkan Keyoumars
Department of Neuroradiology, King's College Hospital, London, UK. r.o'
Stereotact Funct Neurosurg. 2009;87(4):205-10. doi: 10.1159/000225973. Epub 2009 Jun 26.
BACKGROUND/AIMS: Stereotactic postoperative imaging is essential for verification of the position of electrodes implanted for deep brain stimulation (DBS). MRI offers superior visualisation of the DBS targets relative to CT, but previous adverse incidents have heightened concerns about risks of postoperative MRI. Preoperative MRI fused with postoperative CT offers an alternative method for evaluating electrode position, but before this method can be clinically applied, the image registration accuracy must be established. The purpose of this study was to quantitatively assess the accuracy of three different image registration and fusion methods.
Preoperative stereotactic MRI and postoperative stereotactic CT were acquired from 20 patients under- going DBS surgery (35 electrodes in total). The postoperative CT was registered and fused with the preoperative MRI, using three different registration algorithms. The position of each electrode tip was determined in stereotactic coordinates both in the (unfused) postoperative CT and the fused CT/MRI. The difference in tip position between the CT and fused CT/MRI was used to evaluate the registration accuracy.
The mean error along the lateral, anteroposterior, and vertical axes was 0.5, 0.5, and 1 mm, respectively.
CT/MRI fusion provides a safe, practical technique for postoperative identification of DBS electrodes.
背景/目的：立体定向术后成像对于验证植入用于深部脑刺激（DBS）的电极位置至关重要。相对于CT，MRI能更清晰地显示DBS靶点，但先前的不良事件加剧了人们对术后MRI风险的担忧。术前MRI与术后CT融合提供了一种评估电极位置的替代方法，但在该方法可临床应用之前，必须确定图像配准精度。本研究的目的是定量评估三种不同图像配准和融合方法的准确性。
从20例接受DBS手术的患者（共35根电极）获取术前立体定向MRI和术后立体定向CT。使用三种不同的配准算法将术后CT与术前MRI进行配准和融合。在（未融合的）术后CT和融合后的CT/MRI中，以立体定向坐标确定每个电极尖端的位置。CT与融合后的CT/MRI之间尖端位置的差异用于评估配准精度。
沿横轴、前后轴和垂直轴的平均误差分别为0.5、0.5和1毫米。
CT/MRI融合为术后识别DBS电极提供了一种安全、实用的技术。
