Staempfli Philipp, Rienmueller Anna, Reischauer Carolin, Valavanis Anton, Boesiger Peter, Kollias Spyridon
Institute for Biomedical Engineering, Swiss Federal Institute of Technology (ETH) Zurich and University Zurich, Zurich, Switzerland.
J Magn Reson Imaging. 2007 Oct;26(4):886-93. doi: 10.1002/jmri.21098.
To apply and to evaluate the newly developed advanced fast marching algorithm (aFM) in vivo by reconstructing the human visual pathway, which is characterized by areas of extensive fiber crossing and branching, i.e., the optic chiasm and the lateral geniculate nucleus (LGN).
Diffusion tensor images were acquired in 10 healthy volunteers. Due to the proximity to bony structures and air-filled spaces of the optic chiasm, a high sensitivity encoding (SENSE) reduction factor was applied to reduce image distortions in this area. To reconstruct the visual system, three different seed areas were chosen separately. The results obtained by the aFM tracking algorithm were compared and validated with known anatomy.
The visual system could be reconstructed reproducibly in all subjects and the reconstructed fiber pathways are in good agreement with known anatomy.
The present work shows that the advanced aFM, which is especially designed for overcoming tracking limitations within areas of extensive fiber crossing, handles the fiber crossing and branching within the optic chiasm and the LGN correctly, thus allowing the reconstruction of the entire human visual fiber pathway, from the intraorbital segment of the optic nerves to the visual cortex.
通过重建具有广泛纤维交叉和分支区域（即视交叉和外侧膝状体）的人类视觉通路，在体内应用并评估新开发的先进快速行进算法（aFM）。
对10名健康志愿者采集扩散张量图像。由于视交叉靠近骨质结构和含气间隙，应用高灵敏度编码（SENSE）缩减因子以减少该区域的图像失真。为重建视觉系统，分别选择了三个不同的种子区域。将aFM追踪算法获得的结果与已知解剖结构进行比较和验证。
所有受试者的视觉系统均可重复重建，且重建的纤维通路与已知解剖结构高度吻合。
目前的研究表明，专门设计用于克服广泛纤维交叉区域追踪限制的先进aFM，能够正确处理视交叉和外侧膝状体内的纤维交叉和分支，从而实现从视神经眶内段到视觉皮层的整个人类视觉纤维通路的重建。
