Tzeng Yang-Sheng, Hoffman Eric, Cook-Granroth Janice, Gereige Jessica, Mansour Joey, Washko George, Cho Michael, Stepp Evan, Lutchen Kenneth, Albert Mitchell
Department of Radiology, Brigham & Women's Hospital, 221 Longwood Avenue, Boston, MA 02115, USA.
Acad Radiol. 2008 Jun;15(6):799-808. doi: 10.1016/j.acra.2008.02.003.
Application of a previously developed model-based algorithm on hyperpolarized (HP) (3)He magnetic resonance (MR) dynamic projection images of phantoms was extended to investigate the utility of HP (3)He MR imaging (MRI) in quantifying airway caliber changes associated with asthma.
Airways of seven volunteers were imaged and measured using HP (3)He MRI and multidetector-row computed tomography (MDCT) before and after a methacholine (MCh) challenge. MDCT data were obtained at functional residual capacity and 1 L above functional residual capacity.
Comparison of the resultant data showed that HP (3)He MRI did not match MDCT in measuring the ratios of airway calibers before and after the MCh challenge in 37% to 43% of the airways from the first six generations at the two lung volumes tested. However, MDCT did yield the observation that 49% to 69% of these airways displayed bronchodilation following MCh challenge.
The current implementation of HP (3)He MRI did not match the MCh-induced postchallenge-to-prechallenge airway caliber ratios as measured with MDCT. Elevated parenchymal tethering due to bronchoconstriction-induced hyperinflation was proposed as a possible explanation for this airway dilation.
将先前开发的基于模型的算法应用于超极化（HP）（3）氦磁共振（MR）动态投影图像的模型扩展，以研究HP（3）氦磁共振成像（MRI）在量化与哮喘相关的气道管径变化中的效用。
在七名志愿者接受乙酰甲胆碱（MCh）激发前后，使用HP（3）氦MRI和多排螺旋计算机断层扫描（MDCT）对气道进行成像和测量。MDCT数据在功能残气量和高于功能残气量1L时获取。
对所得数据的比较表明，在测试的两个肺容积下，对于前六代气道中37%至43%的气道，HP（3）氦MRI在测量MCh激发前后的气道管径比值方面与MDCT不匹配。然而，MDCT确实观察到这些气道中有49%至69%在MCh激发后出现支气管扩张。
当前HP（3）氦MRI的实施在测量MCh激发后与激发前气道管径比值方面与MDCT不匹配。支气管收缩引起的肺过度充气导致的实质束缚增加被认为是这种气道扩张的一种可能解释。
