氧增强MR肺通气成像的基础研究

目的　探讨氧增强MR肺通气成像的机理和基本技术方法。方法　运用反转恢复单次激发超快速自旋回波序列 ,对 7例 (4男、3女 )健康志愿者进行扫描 ,比较中心编码和半傅立叶K空间填充方式的成像区别 ;采用医用纯氧作为T1加权肺通气对比剂 ,进行吸氧前后的肺组织T1值测量和图像处理。结果　中心编码的K空间填充方式可得到更佳的信噪比 ,合适的翻转恢复时间可得到最优的对比度噪声比 ,通过吸氧前后的图像减影可获得氧对比的肺通气功能图。结论　氧对比通气成像安全、简便易行 ,能反映肺的局部通气功能 ,具有潜在的临床应用价值。

Basic Research of Oxygen-Enhanced MR Ventilation Imaging in Lung

Objective To study the mechanism and basic technique of the oxygen contrast MR ventilation imaging in the lung. Methods The study used an inversion recovery pulse sequence with a single shot turbo spin echo acquisition for each inversion recovery time before and after inhalation of the pure oxygen as T 1 contrast agent to measure T 1 values in seven healthy volunteers (4 males,3 females),and compared phase encoding scheme of the centrically recordered and half scan type,which were dealed with the image of pre and post oxygen condition. Results The signal to noise ratio was optimized using a centrically recordered single shot RARE sequence.The contrast to noise ratio was improved using an optimized inversion delay time.Through the subtraction of pre and post oxygen image,we obtained the oxygen contrast MR ventilation image. Conclusion Oxygen enhanced MR ventilation imaging has the feasibility,safty and clinical potentiality for assessment of regional pulmonary function.