Forkert N D, Fiehler J, Suniaga S, Wersching H, Knecht S, Kemmling A
Nils Daniel Forkert, Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Bldg. W36, Martinistraße 52, 20246 Hamburg, Germany, E-mail:
Methods Inf Med. 2013;52(6):467-74. doi: 10.3414/ME13-02-0001. Epub 2013 Nov 5.
The cerebroarterial system is a complex network of arteries that supply the brain cells with vitally important nutrients and oxygen. The inter-individual differences of the cerebral arteries, especially at a finer level, are still not understood sufficiently. The aim of this work is to present a statistical cerebroarterial atlas that can be used to overcome this problem.
Overall, 700 Time-of-Flight (TOF) magnetic resonance angiography (MRA) datasets of healthy subjects were used for atlas generation. Therefore, the cerebral arteries were automatically segmented in each dataset and used for a quantification of the vessel diameters. After this, each TOF MRA dataset as well as the corresponding vessel segmentation and vessel diameter dataset were registered to the MNI brain atlas. Finally, the registered datasets were used to calculate a statistical cerebroarterial atlas that incorporates information about the average TOF intensity, probability for a vessel occurrence and mean vessel diameter for each voxel.
Visual analysis revealed that arteries with a diameter as small as 0.5 mm are well represented in the atlas with quantitative values that are within range of anatomical reference values. Moreover, a highly significant strong positive correlation between the vessel diameter and occurrence probability was found. Furthermore, it was shown that an intensity-based automatic segmentation of cerebral vessels can be considerable improved by incorporating the atlas information leading to results within the range of the inter-observer agreement.
The presented cerebroarterial atlas seems useful for improving the understanding about normal variations of cerebral arteries, initialization of cerebrovascular segmentation methods and may even lay the foundation for a reliable quantification of subtle morphological vascular changes.
脑动脉系统是一个复杂的动脉网络，为脑细胞提供至关重要的营养物质和氧气。脑动脉的个体差异，尤其是在更精细层面上的差异，目前仍未得到充分理解。这项工作的目的是呈现一个统计性脑动脉图谱，以解决这一问题。
总体而言，使用了700例健康受试者的时间飞跃（TOF）磁共振血管造影（MRA）数据集来生成图谱。因此，在每个数据集中自动分割脑动脉，并用于量化血管直径。在此之后，将每个TOF MRA数据集以及相应的血管分割和血管直径数据集配准到MNI脑图谱。最后，使用配准后的数据集计算一个统计性脑动脉图谱，该图谱包含每个体素的平均TOF强度、血管出现概率和平均血管直径等信息。
视觉分析显示，直径小至0.5毫米的动脉在图谱中得到了很好的呈现，其定量值在解剖学参考值范围内。此外，发现血管直径与出现概率之间存在高度显著的强正相关。此外，研究表明，通过纳入图谱信息，基于强度的脑血管自动分割可以得到显著改善，从而使结果在观察者间一致性范围内。
所呈现的脑动脉图谱似乎有助于增进对脑动脉正常变异的理解、初始化脑血管分割方法，甚至可能为可靠量化细微的形态学血管变化奠定基础。
