Luk Wing Hang, Au-Yeung Andrea Wai San, Lo Adrian Xu Ning, Loke Tony Kwok Loon, Ng Tse Woon
Radiol Technol. 2014 May-Jun;85(5):494-9.
To compare the accuracy of cardiovascular magnetic resonance (CMR) imaging methods for measuring left ventricular ejection fraction with multiple-gated acquisition (MUGA). CMR imaging methods included in-line tracking, in-line automated tracking with manual adjustment (a semiautomatic technique), and manual drawing techniques.
Thirty patients were recruited for left ventricular ejection fraction (LVEF) assessment. The LVEF was measured by CMR imaging using in-line automated tracking, the semiautomatic technique, and manual contouring and segmentation. These methods were then followed by a MUGA scan. Results of all 4 methods were compared for LVEF percentage and measuring time. Repeated analysis of variance testing was used to determine any significant difference between the means of measuring the LVEF. A P value of less than .05 was considered statistically significant.
The mean LVEF measured by CMR imaging using in-line automated tracking, a semiautomatic technique, and manual drawing were 52.9% (standard deviation [SD] 8.5), 62.3% (SD 8.1), and 62.2% (SD 7.8), respectively. The mean LVEF with the MUGA scan was 64.4% (SD 8.4). The MUGA scan, semiautomatic technique, and manual measurement using CMR imaging were statistically significantly different from the CMR imaging using in-line automated tracking for LVEF calculation (all P values < .01).
Using in-line automated tracking, the end systolic volume was overestimated, which resulted in the underestimation of the LVEF. A therapeutic plan based on an inaccurate and low LVEF measurement could be dangerous because it might suggest a drug-related cardiotoxicity, and medication might be discontinued.
A semiautomated technique with manual adjustment of the cardiac contours and basal slice selection in CMR imaging is time saving and comparable with the MUGA scan for the accurate documentation of LVEF.
比较心血管磁共振（CMR）成像方法与多门控采集（MUGA）测量左心室射血分数的准确性。CMR成像方法包括在线跟踪、带手动调整的在线自动跟踪（一种半自动技术）以及手动绘制技术。
招募30例患者进行左心室射血分数（LVEF）评估。使用在线自动跟踪、半自动技术和手动轮廓描绘及分割通过CMR成像测量LVEF。然后对这些方法进行MUGA扫描。比较所有4种方法在LVEF百分比和测量时间方面的结果。采用重复方差分析检验来确定测量LVEF的均值之间是否存在显著差异。P值小于0.05被认为具有统计学意义。
使用在线自动跟踪、半自动技术和手动绘制通过CMR成像测量的平均LVEF分别为52.9%（标准差[SD]8.5）、62.3%（SD 8.1）和62.2%（SD 7.8）。MUGA扫描的平均LVEF为64.4%（SD 8.4）。在计算LVEF时，MUGA扫描、半自动技术以及使用CMR成像的手动测量与使用在线自动跟踪的CMR成像在统计学上有显著差异（所有P值<0.01）。
使用在线自动跟踪时，收缩末期容积被高估，导致LVEF被低估。基于不准确且较低的LVEF测量制定治疗方案可能很危险，因为这可能提示药物相关的心脏毒性，并且可能会停用药物。
在CMR成像中采用带心脏轮廓手动调整和基底部切片选择的半自动技术节省时间，且在准确记录LVEF方面与MUGA扫描相当。
