Zhan Yuxuan, Eggebrecht Adam T, Culver Joseph P, Dehghani Hamid
School of Computer Science, University of Birmingham Birmingham, UK.
Front Neuroenergetics. 2012 May 24;4:6. doi: 10.3389/fnene.2012.00006. eCollection 2012.
High-density diffuse optical tomography (HD-DOT) methods have shown significant improvement in localization accuracy and image resolution compared to traditional topographic near infrared spectroscopy of the human brain. In this work we provide a comprehensive evaluation of image quality in visual cortex mapping via a simulation study with the use of an anatomical head model derived from MRI data of a human subject. A model of individual head anatomy provides the surface shape and internal structure that allow for the construction of a more realistic physical model for the forward problem, as well as the use of a structural constraint in the inverse problem. The HD-DOT model utilized here incorporates multiple source-detector separations with continuous-wave data with added noise based on experimental results. To evaluate image quality we quantify the localization error and localized volume at half maximum (LVHM) throughout a region of interest within the visual cortex and systematically analyze the use of whole-brain tissue spatial constraint within image reconstruction. Our results demonstrate that an image quality with less than 10 mm in localization error and 1000 m(3) in LVHM can be obtained up to 13 mm below the scalp surface with a typical unconstrained reconstruction and up to 18 mm deep when a whole-brain spatial constraint based on the brain tissue is utilized.
与传统的人脑近红外光谱地形图相比，高密度漫射光学断层扫描（HD-DOT）方法在定位精度和图像分辨率方面有显著提高。在这项工作中，我们通过使用从人类受试者的MRI数据导出的解剖头部模型进行模拟研究，对视觉皮层映射中的图像质量进行了全面评估。个体头部解剖模型提供了表面形状和内部结构，这有助于构建更逼真的正向问题物理模型，并在逆问题中使用结构约束。这里使用的HD-DOT模型结合了多个源-探测器间距，并根据实验结果对连续波数据添加噪声。为了评估图像质量，我们在视觉皮层的感兴趣区域内量化定位误差和半高宽处的定位体积（LVHM），并系统地分析图像重建中全脑组织空间约束的使用。我们的结果表明，在典型的无约束重建中，在头皮表面以下13毫米处可获得定位误差小于10毫米且LVHM小于1000立方米的图像质量，而在使用基于脑组织的全脑空间约束时，深度可达18毫米。
