Molinari Francesco, Gaudino Simona, Fink Christian, Corbo Giuseppe Maria, Valente Salvatore, Pirronti Tommaso, Bonomo Lorenzo
Department of Radiological Sciences, Catholic University of Rome, Rome, Italy.
Invest Radiol. 2006 May;41(5):476-85. doi: 10.1097/01.rli.0000208240.08299.5d.
We sought to evaluate an optimized method for oxygen-enhanced magnetic resonance imaging of the lung, using electrocardiogram-trigger and a pneumotachograph for simultaneous cardiac and respiratory synchronization.
Five series of IR-SSFSE images (echo time = 28.2 milliseconds; inversion time = 1,200 milliseconds) were obtained in 6 volunteers during the ventilation-paradigm room-air/oxygen/room-air: series 1, respiratory-triggered; series 2, cardiac-triggered; series 3, cardiac-triggered and respiratory-synchronized using the signal of the pneumatic belt; series 4, cardiac-triggered and respiratory-synchronized using the external signal of the pneumotachograph; and series 5, not cardiac-triggered and respiratory-synchronized using the signal of the pneumotachograph. Standard deviations of the lung (SI(var)) and diaphragm mismatch (DM) were measured. The relative SI change (DeltaSI) was computed from room-air and oxygen-enhanced images. Parametric maps were obtained from cross-correlation analysis of the ventilation paradigm. Mean correlation coefficients (cc) and the percentage of activated pixels over the lung (Act%) were calculated from these maps. All 5 parameters were compared among the 5 series (Friedman-analysis of variance, Dunn's posthoc test).
In series 4, DM and SI(var) were significantly lower than in respiratory and cardiac-triggered series (DM = 4.7 vs. 14.3 and 18.4; SI(var) = 4.9 vs. 10 and 11). In the same series cc and Act% also were significantly higher than in series 1 and 2 (cc = 0.86 vs. 0.7 and 0.6; Act% = 71.3 vs. 44.7 and 41.2). DeltaSI was not significantly different among all series.
Effective respiratory and cardiac synchronization can be achieved in oxygen-enhanced magnetic resonance imaging of the lung, using a pneumotachograph for real-time targeting of end-expiration.
我们试图评估一种优化的肺部氧增强磁共振成像方法，该方法使用心电图触发和呼吸流速仪实现心脏与呼吸的同步。
在6名志愿者进行通气模式（室内空气/氧气/室内空气）时，获取了5组IR-SSFSE图像（回波时间 = 28.2毫秒；反转时间 = 1200毫秒）：第1组，呼吸触发；第2组，心脏触发；第3组，使用气动带信号进行心脏触发和呼吸同步；第4组，使用呼吸流速仪的外部信号进行心脏触发和呼吸同步；第5组，不进行心脏触发，使用呼吸流速仪的信号进行呼吸同步。测量了肺部的标准差（SI(var)）和膈肌不匹配度（DM）。根据室内空气和氧增强图像计算相对SI变化（DeltaSI）。通过通气模式的互相关分析获得参数图。从这些图中计算平均相关系数（cc）和肺部激活像素的百分比（Act%）。对这5组的所有5个参数进行比较（Friedman方差分析，Dunn事后检验）。
在第4组中，DM和SI(var)显著低于呼吸触发组和心脏触发组（DM = 4.7对14.3和18.4；SI(var) = 4.9对10和11）。在同一组中，cc和Act%也显著高于第1组和第2组（cc = 0.86对0.7和0.6；Act% = 71.3对44.7和41.2）。DeltaSI在所有组之间无显著差异。
在肺部氧增强磁共振成像中，使用呼吸流速仪实时靶向呼气末可实现有效的呼吸和心脏同步。
