Lucas-Neto Lia, Reimão Sofia, Oliveira Edson, Rainha-Campos Alexandre, Sousa João, Nunes Rita G, Gonçalves-Ferreira António, Campos Jorge G
Anatomy Department, Lisbon Medical School, Lisboa, Portugal.
Neuroradiology Department, North Lisbon Medical Center, Lisboa, Portugal.
Neuromodulation. 2015 Jul;18(5):341-8. doi: 10.1111/ner.12289. Epub 2015 Apr 16.
The human nucleus accumbens (Acc) has become a target for deep brain stimulation (DBS) in some neuropsychiatric disorders. Nonetheless, even with the most recent advances in neuroimaging it remains difficult to accurately delineate the Acc and closely related subcortical structures, by conventional MRI sequences. It is our purpose to perform a MRI study of the human Acc and to determine whether there are reliable anatomical landmarks that enable the precise location and identification of the nucleus and its core/shell division.
For the Acc identification and delineation, based on anatomical landmarks, T1WI, T1IR and STIR 3T-MR images were acquired in 10 healthy volunteers. Additionally, 32-direction DTI was obtained for Acc segmentation. Seed masks for the Acc were generated with FreeSurfer and probabilistic tractography was performed using FSL. The probability of connectivity between the seed voxels and distinct brain areas was determined and subjected to k-means clustering analysis, defining 2 different regions.
With conventional T1WI, the Acc borders are better defined through its surrounding anatomical structures. The DTI color-coded vector maps and IR sequences add further detail in the Acc identification and delineation. Additionally, using probabilistic tractography it is possible to segment the Acc into a core and shell division and establish its structural connectivity with different brain areas.
Advanced MRI techniques allow in vivo delineation and segmentation of the human Acc and represent an additional guiding tool in the precise and safe target definition for DBS.
在某些神经精神疾病中，人类伏隔核已成为深部脑刺激（DBS）的靶点。然而，即使有神经影像学的最新进展，通过传统的MRI序列准确描绘伏隔核及与之紧密相关的皮质下结构仍很困难。我们的目的是对人类伏隔核进行MRI研究，并确定是否存在可靠的解剖标志，以实现对该核及其核心/壳层划分的精确定位和识别。
为了识别和描绘伏隔核，基于解剖标志，在10名健康志愿者中采集了T1WI、T1IR和STIR 3T-MR图像。此外，还获得了3D方向的DTI用于伏隔核分割。使用FreeSurfer生成伏隔核的种子掩码，并使用FSL进行概率性纤维束成像。确定种子体素与不同脑区之间的连接概率，并进行k均值聚类分析，定义2个不同区域。
通过传统的T1WI，伏隔核的边界通过其周围的解剖结构能得到更好的界定。DTI彩色编码矢量图和IR序列在伏隔核的识别和描绘中增加了更多细节。此外，使用概率性纤维束成像可以将伏隔核分割为核心和壳层，并建立其与不同脑区的结构连接。
先进的MRI技术能够在体内描绘和分割人类伏隔核，并为DBS精确安全的靶点定义提供了额外的指导工具。
