在侵入性脑电图记录中，使用弹性图像融合算法在磁共振成像上改善植入的硬膜下电极触点的定位。

Improved localization of implanted subdural electrode contacts on magnetic resonance imaging with an elastic image fusion algorithm in an invasive electroencephalography recording.

作者信息

Stieglitz Lennart Henning, Ayer Christian, Schindler Kaspar, Oertel Markus Florian, Wiest Roland, Pollo Claudio

机构信息

*Department of Neurosurgery, Zurich University Hospital, University of Zurich, Zurich, Switzerland; ‡University of Bern, Bern, Switzerland; §Department of Neurology, ¶Department of Neurosurgery, and ‖Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.

出版信息

Neurosurgery. 2014 Dec;10 Suppl 4:506-12; discussion 512-3. doi: 10.1227/NEU.0000000000000473.

DOI:10.1227/NEU.0000000000000473

PMID:24978648

Abstract

BACKGROUND

Accurate projection of implanted subdural electrode contacts in presurgical evaluation of pharmacoresistant epilepsy cases by invasive electroencephalography is highly relevant. Linear fusion of computed tomography and magnetic resonance images may display the contacts in the wrong position as a result of brain shift effects.

OBJECTIVE

A retrospective study in 5 patients with pharmacoresistant epilepsy was performed to evaluate whether an elastic image fusion algorithm can provide a more accurate projection of the electrode contacts on the preimplantation magnetic resonance images compared with linear fusion.

METHODS

An automated elastic image fusion algorithm (AEF), a guided elastic image fusion algorithm (GEF), and a standard linear fusion algorithm were used on preoperative magnetic resonance images and postimplantation computed tomography scans. Vertical correction of virtual contact positions, total virtual contact shift, corrections of midline shift, and brain shifts caused by pneumocephalus were measured.

RESULTS

Both AEF and GEF worked well with all 5 cases. An average midline shift of 1.7 mm (SD, 1.25 mm) was corrected to 0.4 mm (SD, 0.8 mm) after AEF and to 0.0 mm (SD, 0 mm) after GEF. Median virtual distances between contacts and cortical surface were corrected by a significant amount, from 2.3 mm after linear fusion algorithm to 0.0 mm after AEF and GEF (P < .001). Mean total relative corrections of 3.1 mm (SD, 1.85 mm) after AEF and 3.0 mm (SD, 1.77 mm) after GEF were achieved. The tested version of GEF did not achieve a satisfying virtual correction of pneumocephalus.

CONCLUSION

The technique provided a clear improvement in fusion of preimplantation and postimplantation scans, although the accuracy is difficult to evaluate.

摘要

背景

在药物难治性癫痫病例的术前评估中，通过侵入性脑电图对植入的硬膜下电极触点进行准确投影至关重要。计算机断层扫描和磁共振图像的线性融合可能会因脑移位效应而使触点显示在错误位置。

目的

对5例药物难治性癫痫患者进行回顾性研究，以评估与线性融合相比，弹性图像融合算法是否能在植入前磁共振图像上更准确地投影电极触点。

方法

在术前磁共振图像和植入后计算机断层扫描上使用自动弹性图像融合算法（AEF）、引导弹性图像融合算法（GEF）和标准线性融合算法。测量虚拟触点位置的垂直校正、总虚拟触点移位、中线移位校正以及由气颅引起的脑移位。

结果

AEF和GEF在所有5例中均效果良好。AEF后平均中线移位从1.7 mm（标准差，1.25 mm）校正至0.4 mm（标准差，0.8 mm），GEF后校正至0.0 mm（标准差，0 mm）。触点与皮质表面之间的中位虚拟距离得到显著校正，从线性融合算法后的2.3 mm校正至AEF和GEF后的0.0 mm（P <.001）。AEF后平均总相对校正为3.1 mm（标准差，1.85 mm），GEF后为3.0 mm（标准差，1.77 mm）。所测试版本的GEF未实现对气颅的满意虚拟校正。