Department of Internal Medicine 2 (Cardiology), University of Erlangen, Germany.
Eur J Radiol. 2009 Oct;72(1):85-91. doi: 10.1016/j.ejrad.2008.06.012. Epub 2008 Jul 11.
Assessment of left ventricular function is possible in contrast-enhanced cardiac CT data sets. However, rapid ventricular motion especially in systole can lead to artifacts. Dual Source Computed Tomography (DSCT) has high temporal resolution which effectively limits motion artifact. We therefore assessed the accuracy of DSCT to detect regional left ventricular wall motion abnormalities in comparison to invasive cine angiocardiography.
We analyzed DSCT data sets of 50 patients (39 male, 11 female, mean age: 61+/-10 years) which were acquired after intravenous injection of 55-70 mL contrast agent (rotation time: 330 ms, collimation: 2 mm x 64 mm x 0.6 mm, 120 kV, 380 mAs, ECG-correlated tube current modulation). 10 data sets consisting of transaxial slices with a slice thickness of 1.5 mm, an increment of 1.0 mm and a matrix of 256 x 256 pixels were reconstructed at 10 time instants during the cardiac cycle (0-90% in 10% increments). The data sets were analyzed visually by two independent readers, using standard left ventricular planes, concerning regional wall motion abnormalities. DSCT was verified in a blinded fashion against cine ventriculography performed during cardiac catheterization (RAO and LAO projection), using a 7-segment model. Analysis was performed on a per-patient (presence of at least one hypo-, a- or dyskinetic segment) and on a per-segment basis.
Concerning the presence of a wall motion abnormality, the two observers agreed in 340/350 segments (97%) and 48/50 patients (96%). In invasive cine angiocardiography, 22 of 50 patients displayed at least one segment with abnormal contraction. To detect these patients, DSCT showed a sensitivity of 95% (21/22), specificity of 96% (27/28), positive predictive value of 95% and negative predictive value of 96%. Out of a total of 350 left ventricular segments, 66 segments had abnormal contraction in cine angiocardiography (34 hypokinetic, 26 akinetic, 6 dyskinetic). For detection of these segments, DSCT had a sensitivity of 88% (58/66), specificity of 98% (278/284), positive predictive value of 91% (58/64) and negative predictive value of 97% (278/286).
DSCT allows the detection of regional wall motion abnormalities with high interobserver agreement as well as high sensitivity and specificity. Whereas sensitivity and positive predictive value were higher in a per-patient- in comparison to a per-segment-based analysis, specificity, negative predictive value and interobserver agreement did not differ considerably between both analyzing methods.
在对比增强的心脏 CT 数据集上可以评估左心室功能。然而，快速的心室运动，尤其是在收缩期，会导致伪影。双源 CT（DSCT）具有较高的时间分辨率，可有效限制运动伪影。因此，我们评估了 DSCT 在检测局部左心室壁运动异常方面的准确性，与有创的电影心血管造影相比。
我们分析了 50 例患者（39 名男性，11 名女性，平均年龄：61+/-10 岁）的 DSCT 数据集，这些患者在静脉注射 55-70ml 造影剂后采集（旋转时间：330ms，准直：2mm x 64mm x 0.6mm，120kV，380mAs，ECG 相关管电流调制）。10 个数据集由 1.5mm 厚的横轴切片组成，增量为 1.0mm，矩阵为 256x256 像素，在心脏周期的 10 个时间点（0-90%，以 10%的增量）进行重建。使用标准的左心室平面，由两名独立的观察者对数据集进行视觉分析，以确定局部壁运动异常。DSCT 以盲法与在导管插入术期间进行的电影心室造影（RAO 和 LAO 投影）进行比较，使用 7 节段模型进行分析。在每位患者（至少存在一个低、无或运动不良节段）和每个节段的基础上进行分析。
在存在壁运动异常方面，两名观察者在 350/350 个节段（97%）和 48/50 名患者（96%）中达成一致。在有创性电影心血管造影中，50 名患者中有 22 名至少有一个节段显示收缩异常。为了检测到这些患者，DSCT 的敏感性为 95%（21/22），特异性为 96%（27/28），阳性预测值为 95%，阴性预测值为 96%。在总共 350 个左心室节段中，有 66 个节段在电影心血管造影中显示收缩异常（34 个运动不良，26 个无运动，6 个运动不良）。对于这些节段的检测，DSCT 的敏感性为 88%（58/66），特异性为 98%（278/284），阳性预测值为 91%（58/64），阴性预测值为 97%（278/286）。
DSCT 可检测到局部壁运动异常，具有较高的观察者间一致性以及较高的敏感性和特异性。虽然在患者层面的分析中，敏感性和阳性预测值高于节段层面的分析，但特异性、阴性预测值和观察者间一致性在两种分析方法之间差异不大。
