近红外光学断层成像术定位早产儿头部深度缺血和出血：数值案例研究。

Localization of Deep Ischemia and Hemorrhage in Preterm Infants' Head with Near-Infrared Optical Tomography: A Numerical Case Study.

机构信息

Biomedical Optics Research Laboratory (BORL), Department of Neonatology, University Hospital Zürich and University of Zürich, Zurich, Switzerland.

出版信息

Adv Exp Med Biol. 2021;1269:131-136. doi: 10.1007/978-3-030-48238-1_21.

DOI:10.1007/978-3-030-48238-1_21

Abstract

BACKGROUND AND AIM

Preterm infants have a high incidence of brain lesions that may lead to long-term disabilities. Early diagnosis of cerebral ischemia and hemorrhage may enable protection of the brain by prevention or neuroprotective treatment. Our recently developed time-domain near-infrared optical tomography (TD NIROT) system provides images to diagnose neonatal brain injury. Our aim is to study the image quality achievable from the TD NIROT signals perturbed by noise for two common cases: ischemia and hemorrhage.

METHODS

We implemented simulations on a spherical model of diameter 60 mm representing a typical neonatal head where the absorption μ = 0.08 cm and the reduced scattering μ' = 4.1 cm. Injury-mimicking spherical inclusions of various diameters (1 ~ 10 mm) were placed at depths of 10 ~ 20 mm in the ischemia case (2.5 × μ) and 14 ~ 30 mm for the hemorrhage case (50 × μ). TD data were generated from a large number of source-detector pairs, i.e., 208 detectors placed within a circle of diameter 40 mm on the surface surrounded by 18 sources. Up to 5% Gaussian noise was added in the simulations. 3D images were reconstructed with the modified Tikhonov minimization with the initial guess of a homogeneous phantom, and the images were evaluated by positional error and Dice similarity.

RESULTS

The inclusions were localized correctly with low positional errors (<1 mm), and the segmented images share a high Dice similarity with the ground truth for both the ischemia and the hemorrhage case, even for tiny inclusions of 1 mm in deep tissue. The hemorrhage case with a high contrast tolerates a substantial level of noise even though the performance drops with higher noise as expected.

CONCLUSIONS

The large amount of data provided by our novel TD NIROT system provides rich enough information for correctly locating hemorrhage and ischemia in the neonatal brain.

摘要

背景与目的

早产儿脑损伤发生率高，可能导致长期残疾。早期诊断脑缺血和脑出血，通过预防或神经保护治疗，可能有助于保护大脑。我们最近开发的时域近红外光学断层成像（TD NIROT）系统提供了诊断新生儿脑损伤的图像。我们的目的是研究受噪声干扰的 TD NIROT 信号的图像质量，针对两种常见情况：缺血和出血。

方法

我们在一个直径为 60mm 的球形模型上进行了模拟，该模型代表了一个典型的新生儿头部，其吸收系数 μ = 0.08cm，散射系数 μ' = 4.1cm。在缺血情况下（2.5×μ），将直径为 1 至 10mm 的各种损伤模拟球形内插物放置在 10 至 20mm 深处，在出血情况下（50×μ），将其放置在 14 至 30mm 深处。从大量源-探测器对生成 TD 数据，即在表面直径 40mm 的圆上放置 208 个探测器，并由 18 个源环绕。在模拟中添加了高达 5%的高斯噪声。使用改进的 Tikhonov 最小化方法进行 3D 图像重建，初始猜测为均匀体模，并通过位置误差和 Dice 相似性评估图像。