Dynamic In Vivo Chest X-ray Dark-Field Imaging in Mice
Dynamic In Vivo Chest X-ray Dark-Field Imaging in Mice
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DOI：
10.1109/tmi.2018.2868999
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发表时间：
2019-02-01
影响因子：
10.6
通讯作者：
Pfeiffer, F.
中科院分区：
文献类型：
--
作者：
Gradl, R.;Morgan, K. S.;Pfeiffer, F.
X射线光栅干涉计量学是生物医学成像中一种强大的新兴工具，它提供了三种互补的成像方式。除了传统的衰减模式外，干涉测量还提供了显示软组织结构的相位模式和与亚分辨率散射对象的数量和大小相关的暗场模式。一个特别强的暗视野信号来自肺内的肺泡或气囊。动物模型中的暗视野肺部X光照片已经表明，与传统的X射线胸片相比，在诊断肺癌或肺气肿等肺部疾病方面具有更高的敏感度。然而，到目前为止，X射线暗视野肺成像要么在几次呼吸中平均信息，要么在屏气期间捕捉到信息。在这篇文章中，我们展示了第一次在活体机械通气小鼠呼吸周期的时间分辨暗场成像，这是使用光栅干涉仪获得的。我们获得了0.1 S的时间分辨率，可视化了吸气和呼气过程中暗视野、相位和衰减图像的变化。这些测量表明，暗视野信号取决于空气体积，因此取决于肺的肺泡大小。用动物疾病模型进行这种类型的扫描将有助于定位单幅图像诊断暗视野成像的最佳呼吸点，并可以指示呼吸过程中暗视野信号的变化是否提供了诊断有用的补充措施。
X-ray grating interferometry is a powerful emerging tool in biomedical imaging, providing access to three complementary image modalities. In addition to the conventional attenuation modality, interferometry provides a phase modality, which visualizes soft tissue structures, and a dark-field modality, which relates to the number and size of sub-resolution scattering objects. A particularly strong dark-field signal originates from the alveoli or air sacs in the lung. Dark-field lung radiographs in animal models have already shown increased sensitivity in diagnosing lung diseases, such as lung cancer or emphysema, compared to conventional X-ray chest radiography. However, to date, X-ray dark-field lung imaging has either averaged information over several breaths or has been captured during a breath hold. In this paper, we demonstrate the first time-resolved dark-field imaging of a breath cycle in a mechanically ventilated mouse, in vivo, which was obtained using a grating interferometer. We achieved a time resolution of 0.1 s, visualizing the changes in the dark-field, phase, and attenuation images during inhalation and exhalation. These measurements show that the dark-field signal depends on the air volume and, hence, the alveolar dimensions of the lung. Conducting this type of scan with animal disease models would help to locate the optimum breath point for single-image diagnostic dark-field imaging and could indicate if the changes in the dark-field signal during breath provide a diagnostically useful complementary measure.