在肺部氧增强磁共振成像中使用呼吸速度描记器进行呼吸监测以实现心脏与呼吸的同步。

Simultaneous cardiac and respiratory synchronization in oxygen-enhanced magnetic resonance imaging of the lung using a pneumotachograph for respiratory monitoring.

作者信息

Molinari Francesco, Gaudino Simona, Fink Christian, Corbo Giuseppe Maria, Valente Salvatore, Pirronti Tommaso, Bonomo Lorenzo

机构信息

Department of Radiological Sciences, Catholic University of Rome, Rome, Italy.

出版信息

Invest Radiol. 2006 May;41(5):476-85. doi: 10.1097/01.rli.0000208240.08299.5d.

DOI:10.1097/01.rli.0000208240.08299.5d

PMID:16625111

Abstract

OBJECTIVES

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.

MATERIALS AND METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

摘要

目的

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。

材料与方法

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）。

结果

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。