Dornier Christophe, Somsen G Aernout, Ivancevic Marko K, Osman Nael F, Didier Dominique, Righetti Alberto, Vallée Jean-Paul
Département de Radiologie et d'Informatique Medicale, Hôpitaux Universitaires de Genève, 24 rue Micheli-du-Crest, 1211 Geneva, Switzerland.
Eur Radiol. 2004 Aug;14(8):1348-52. doi: 10.1007/s00330-004-2311-7. Epub 2004 Apr 6.
Global left ventricular function is a prognostic indicator and is used to evaluate therapeutical interventions in patients with heart failure. Regional left ventricular function can be determined with tagged MRI. Assessment of global left ventricular function using the tagging data may have additional clinical value without incurring extra scanning time, which is currently a limiting factor in cardiac imaging. Direct determination of end-diastolic volume is not possible with conventional tagged MRI. However, end-systolic volume can be directly measured because myocardium-blood contrast improves through a tagged image series. We investigated the potential of tagged MRI using frequency-domain analysis software to retrospectively track end-diastolic contour from end-systolic contour and subsequently calculate the ejection fraction. Tagged MRI was compared with the standard bright-blood cine MRI in healthy volunteers ( n=20) and patients with previous myocardial infarction ( n=8). Left ventricular ejection fraction derived from tagged MRI is linearly correlated to left ventricular ejection fraction obtained by standard cardiac cine MRI ( y=1.0 x+1.31, r>0.98, p=0.014). In addition, the inter-observer and intra-observer coefficient of variation for left ventricular ejection fraction measurements was low (CV(intra)=0.4%, CV(inter)=1.3%). With tagged MRI, only end-systolic volume needs to be manually determined, and accurate estimation of left ventricular ejection fraction is obtained because end-diastolic and end-systolic volumes are determined using identical anatomical points. Our data indicate that tagged MRI can be used to quantitatively assess both regional and global left ventricular function. Therefore, tagged MRI may be a valuable clinical tool for determining the prognosis and evaluating the effect of therapeutical intervention using a single imaging session in patients with left ventricular dysfunction.
整体左心室功能是一种预后指标，用于评估心力衰竭患者的治疗干预措施。局部左心室功能可通过标记磁共振成像（MRI）来确定。利用标记数据评估整体左心室功能可能具有额外的临床价值，且无需额外的扫描时间，而扫描时间目前是心脏成像中的一个限制因素。传统的标记MRI无法直接测定舒张末期容积。然而，由于通过标记图像序列可改善心肌与血液的对比度，因此可以直接测量收缩末期容积。我们利用频域分析软件研究了标记MRI从收缩末期轮廓回顾性追踪舒张末期轮廓并随后计算射血分数的潜力。在20名健康志愿者和8名既往有心肌梗死的患者中，将标记MRI与标准亮血电影MRI进行了比较。标记MRI得出的左心室射血分数与标准心脏电影MRI获得的左心室射血分数呈线性相关（y = 1.0x + 1.31，r>0.98，p = 0.014）。此外，左心室射血分数测量的观察者间和观察者内变异系数较低（CV（观察者内）= 0.4% , CV（观察者间）= 1.3%）。使用标记MRI时，只需手动确定收缩末期容积，由于舒张末期和收缩末期容积是使用相同的解剖学点确定的，因此可准确估计左心室射血分数。我们的数据表明，标记MRI可用于定量评估局部和整体左心室功能。因此，标记MRI可能是一种有价值的临床工具，可用于确定左心室功能不全患者的预后，并通过单次成像检查评估治疗干预的效果。
