Monfraix Sylvie, Bayat Sam, Porra Liisa, Berruyer Gilles, Nemoz Christian, Thomlinson William, Suortti Pekka, Sovijärvi Anssi R A
European Synchrotron Radiation Facility, F-38043 Grenoble, France.
Phys Med Biol. 2005 Jan 7;50(1):1-11. doi: 10.1088/0031-9155/50/1/001.
The aim of this study was to assess the feasibility of a novel respiration-gated spiral synchrotron radiation computed tomography (SRCT) technique for direct quantification of absolute regional lung volumes, using stable xenon (Xe) gas as an inhaled indicator. Spiral SRCT with K-edge subtraction using two monochromatic x-ray beams was used to visualize and directly quantify inhaled Xe concentrations and airspace volumes in three-dimensional (3D) reconstructed lung images. Volume measurements were validated using a hollow Xe-filled phantom. Spiral images spanning 49 mm in lung height were acquired following 60 breaths of an 80% Xe-20% O2 gas mixture, in two anaesthetized and mechanically ventilated rabbits at baseline and after histamine aerosol inhalation. Volumetric images of 20 mm lung sections were obtained at functional residual capacity (FRC) and at end-inspiration. 3D images showed large patchy filling defects in peripheral airways and alveoli following histamine provocation. Local specific lung compliance was calculated based on FRC/end-inspiration images in normal lung. This study demonstrates spiral SRCT as a new technique for direct determination of regional lung volume, offering possibilities for non-invasive investigation of regional lung function and mechanics, with a uniquely high spatial resolution. An example of non-uniform volume distribution in rabbit lung following histamine inhalation is presented.
本研究的目的是评估一种新型呼吸门控螺旋同步辐射计算机断层扫描（SRCT）技术的可行性，该技术使用稳定的氙气（Xe）作为吸入指示剂，直接定量绝对区域肺容积。使用具有K边减法的螺旋SRCT和两个单色X射线束来可视化并直接定量三维（3D）重建肺图像中的吸入Xe浓度和空域容积。使用空心Xe填充体模对容积测量进行验证。在两只麻醉并机械通气的兔子中，在基线和组胺气雾剂吸入后，在吸入80%Xe-20%O2混合气体60次呼吸后，采集了跨越49mm肺高度的螺旋图像。在功能残气量（FRC）和吸气末获得了20mm肺切片的容积图像。3D图像显示组胺激发后外周气道和肺泡出现大片状充盈缺损。基于正常肺中FRC/吸气末图像计算局部比肺顺应性。本研究证明螺旋SRCT是一种直接测定区域肺容积的新技术，为区域肺功能和力学的无创研究提供了可能性，具有独特的高空间分辨率。展示了组胺吸入后兔肺中体积分布不均匀的一个例子。
