Rayarao Geetha, Biederman Robert W W, Williams Ronald B, Yamrozik June A, Lombardi Richard, Doyle Mark
Gerald McGinnis Cardiovascular Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, United States.
J Med Imaging (Bellingham). 2018 Jan;5(1):014004. doi: 10.1117/1.JMI.5.1.014004. Epub 2018 Feb 14.
To establish the clinical validity and accuracy of automatic thresholding and manual trimming (ATMT) by comparing the method with the conventional contouring method for cardiac volume measurements. CMR was performed on 40 subjects (30 patients and 10 controls) using steady-state free precession cine sequences with slices oriented in the short-axis and acquired contiguously from base to apex. Left ventricular (LV) volumes, end-diastolic volume, end-systolic volume, and stroke volume (SV) were obtained with ATMT and with the conventional contouring method. Additionally, SV was measured independently using CMR phase velocity mapping (PVM) of the aorta for validation. Three methods of calculating SV were compared by applying Bland-Altman analysis. The Bland-Altman standard deviation of variation (SD) and offset bias for LV SV for the three sets of data were: ATMT-PVM (7.65, [Formula: see text]), ATMT-contours (7.85, [Formula: see text]), and contour-PVM (11.01, 4.97), respectively. Equating the observed range to the error contribution of each approach, the error magnitude of ATMT:PVM:contours was in the ratio 1:2.4:2.5. Use of ATMT for measuring ventricular volumes accommodates trabeculae and papillary structures more intuitively than contemporary contouring methods. This results in lower variation when analyzing cardiac structure and function and consequently improved accuracy in assessing chamber volumes.
通过将自动阈值分割和手动裁剪（ATMT）方法与传统的轮廓描绘法进行比较，以确定其在心脏容积测量中的临床有效性和准确性。对40名受试者（30例患者和10名对照）进行心脏磁共振成像（CMR）检查，使用稳态自由进动电影序列，扫描层面为短轴方向，从心底到心尖连续采集图像。采用ATMT和传统轮廓描绘法获取左心室（LV）容积、舒张末期容积、收缩末期容积和每搏输出量（SV）。此外，独立使用主动脉的CMR相速度映射（PVM）测量SV以进行验证。应用Bland-Altman分析比较三种计算SV的方法。三组数据中LV SV的Bland-Altman变异标准差（SD）和偏移偏差分别为：ATMT-PVM（7.65，[公式：见原文]），ATMT-轮廓描绘法（7.85，[公式：见原文]）和轮廓描绘法-PVM（11.01，4.97）。将观察范围等同于每种方法的误差贡献，ATMT：PVM：轮廓描绘法的误差大小比例为1：2.4：2.5。与当代轮廓描绘法相比，使用ATMT测量心室容积能更直观地纳入小梁和乳头肌结构。这导致在分析心脏结构和功能时变异更小，从而提高评估心腔容积的准确性。
