Schlosser T, Mohrs O K, Magedanz A, Voigtländer T, Schmermund A, Barkhausen J
Department of Diagnostic and Interventional Radiology, University of Essen, Hufelandstrasse 55, D-45122 Essen, Germany.
Acta Radiol. 2007 Feb;48(1):30-5. doi: 10.1080/02841850601067611.
To quantify left ventricular function and mass derived from retrospectively ECG-gated 64-detector-row computed tomography coronary angiography data sets in comparison to cine magnetic resonance (MR) imaging as the reference standard. We hypothesized that the administration of beta-blockers prior to multidetector computed tomography (MDCT) coronary angiography has a significant impact on left ventricular functional parameters.
Multiplanar reformations in the short-axis orientation were calculated from axial contrast-enhanced CT images in 21 patients (16 male, five female; age range 41-75 years, mean 64.3+/-6.8 years) referred for CT coronary angiography. Patients whose heart rates exceeded 60 bpm received 5 mg bisoprolol orally 1 hour before the MDCT examination. In case of insufficient heart-rate reduction, up to four vials (20 mg) of metoprolol were injected intravenously. The end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and left ventricular mass (LVM) of the reformatted images were analyzed compared to volumetric measurements based on continuous short-axis steady-state free-precession cine MR sequences (TR 3 ms, TE 1.5 ms, FA 60 degrees ).
On average, each patient received 15.5 mg metoprolol (range 0-20 mg) and 3.85 mg bisoprolol (range 0-5 mg). The mean heart rate was 56+/-5 bpm during CT and 73+/-9 bpm during MRI examination. This difference was statistically significant (P<0.05). Mean EDV and ESV measured on MDCT were significantly higher compared to MR (MDCT vs. MR: EDV 164.2+/-52.5 vs. 144.2+/-46.7 ml, ESV 77.3+/-46.6 vs. 63.8+/-47.3 ml; P<0.05). Mean EF and CO derived from MDCT images were significantly lower compared to MR (MDCT vs. MR: EF 55.4+/-11.8 vs. 59.3+/-15.4%, CO 4822+/-779 vs. 5755+/-1267 ml; P<0.05). Mean SV and LVM were not significantly different between both methods (MDCT vs. MR: SV 86.8+/-18.1 vs. 80.3+/-15.6 ml, P = 0.44; LVM 132.4+/-42.5 vs. 138.7+/-39.1 g, P = 0.31).
Left ventricular volumes assessed by the newest-generation MDCT scanners are significantly higher compared with MRI, whereas ejection fraction and cardiac output are significantly lower in MDCT. This appears to be a result of the frequent application of beta-blockers prior to MDCT examinations.
将回顾性心电图门控64排螺旋CT冠状动脉造影数据集得出的左心室功能和质量与作为参考标准的电影磁共振成像进行量化比较。我们假设在多排螺旋CT（MDCT）冠状动脉造影前给予β受体阻滞剂对左心室功能参数有显著影响。
对21例因CT冠状动脉造影前来就诊的患者（16例男性，5例女性；年龄范围41 - 75岁，平均64.3±6.8岁）的轴位对比增强CT图像进行短轴方向的多平面重建。心率超过60次/分的患者在MDCT检查前1小时口服5毫克比索洛尔。若心率降低不足，则静脉注射最多4瓶（20毫克）美托洛尔。将重建图像的舒张末期容积（EDV）、收缩末期容积（ESV）、每搏输出量（SV）、射血分数（EF）、心输出量（CO）和左心室质量（LVM）与基于连续短轴稳态自由进动电影磁共振序列（TR 3毫秒，TE 1.5毫秒，FA 60°）的容积测量结果进行分析比较。
平均而言，每位患者接受了15.5毫克美托洛尔（范围0 - 20毫克）和3.85毫克比索洛尔（范围0 - 5毫克）。CT检查期间平均心率为56±5次/分，MRI检查期间为73±9次/分。这种差异具有统计学意义（P<0.05）。与磁共振成像相比，MDCT测量的平均EDV和ESV显著更高（MDCT与MR：EDV 164.2±52.5对144.2±46.7毫升，ESV 77.3±46.6对63.8±47.3毫升；P<0.05）。与磁共振成像相比，MDCT图像得出的平均EF和CO显著更低（MDCT与MR：EF 55.4±11.8对59.3±15.4%，CO 4822±779对5755±1267毫升；P<0.05）。两种方法之间的平均SV和LVM无显著差异（MDCT与MR：SV 86.8±18.1对80.3±15.6毫升，P = 0.44；LVM 132.4±42.5对138.7±39.1克，P = 0.31）。
与磁共振成像相比，最新一代MDCT扫描仪评估的左心室容积显著更高，而MDCT中的射血分数和心输出量显著更低。这似乎是MDCT检查前频繁应用β受体阻滞剂的结果。
