Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.
Phys Med Biol. 2011 May 21;56(10):3107-22. doi: 10.1088/0031-9155/56/10/014. Epub 2011 Apr 27.
Large airway measurement is clinically important in cases of airway disease and trauma. The gold standard is computed tomography (CT), which allows for airway measurement. However, the ionizing radiation dose associated with CT is a major limitation in longitudinal studies and trauma. To avoid ionizing radiation from CT, we present a method for measuring the large airway diameter in humans using hyperpolarized helium-3 (HPHe) MRI in conjunction with a dynamic 3D radial acquisition. An algorithm is introduced which utilizes the significant airway contrast for semi-automated segmentation and skeletonization which is used to derive the airway lumen diameter. The HPHe MRI method was validated with quantitative CT in an excised and desiccated porcine lung (linear regression R(2) = 0.974 and slope = 0.966 over 32 airway segments). The airway lumen diameters were then compared in 24 human subjects (22 asthmatics and 2 normals; linear regression R(2) value of 0.799 and slope = 0.768 over 309 airway segments). The feasibility for airway path analysis to areas of ventilation defect is also demonstrated.
大气道测量在气道疾病和创伤的临床诊断中非常重要。金标准是计算机断层扫描（CT），它可以进行气道测量。然而，CT 相关的电离辐射剂量在纵向研究和创伤中是一个主要的限制因素。为了避免 CT 的电离辐射，我们提出了一种使用超极化氦-3（HPHe）MRI 结合动态 3D 径向采集来测量人类大气道直径的方法。引入了一种算法，该算法利用显著的气道对比度进行半自动分割和骨架化，从而得出气道腔直径。在离体干燥的猪肺中，HPHe MRI 方法与定量 CT 进行了验证（32 个气道段的线性回归 R(2) = 0.974，斜率 = 0.966）。然后在 24 名人类受试者中比较了气道腔直径（22 名哮喘患者和 2 名正常受试者；309 个气道段的线性回归 R(2)值为 0.799，斜率 = 0.768）。还证明了气道路径分析到通气缺陷区域的可行性。
