Nelson A D, Muswick G J, Muzic R F, Descamps X
Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, School of Medicine, Ohio 44106, USA.
J Nucl Med. 1996 Apr;37(4):685-9.
We present a myocardial edge detection technique that was developed for fast, reproducible measurements of left ventricular ejection fraction in the clinical setting.
This myocardial edge detection method compares three edge parameters--count amplitude and first and second count derivatives--in three consecutive locations along a radius to a predetermined template of these values. Each of the radii, defined at 10-degree intervals, has different template values that permit accurate edge detection even though adjacent structures, such as the left atrium and the right ventricle, alter edge parameters. The template for edge detection is based on either the average edge parameters determined from manually defined edges in 15 patients (automatic method) or an operator-defined edge in the first frame (semiautomatic method).
The edge detection methods were tested in 100 patients, and intraobserver variabilities as well as comparison with clinically obtained ejection fractions were calculated. The standard error of the estimate was less than 3.1% for all observer comparisons. In 15 patients with both high-count (400,000 counts per image) and low count (50,000 counts per image) studies, the mean absolute difference in ejection fraction was 2.6% for intraobserver comparisons.
A robust myocardial edge detection technique was developed that is applicable for routine clinical use.
我们提出了一种心肌边缘检测技术，该技术是为在临床环境中快速、可重复地测量左心室射血分数而开发的。
这种心肌边缘检测方法沿着一条半径在三个连续位置比较三个边缘参数——计数幅度以及第一和第二计数导数——与这些值的预定模板。以10度间隔定义的每条半径都有不同的模板值，即使相邻结构（如左心房和右心室）改变边缘参数，也能实现准确的边缘检测。边缘检测模板基于15名患者手动定义边缘确定的平均边缘参数（自动方法）或第一帧中操作员定义的边缘（半自动方法）。
在100名患者中对边缘检测方法进行了测试，并计算了观察者内变异性以及与临床获得的射血分数的比较。所有观察者比较的估计标准误差均小于3.1%。在15名同时进行高计数（每幅图像400,000计数）和低计数（每幅图像50,000计数）研究的患者中，观察者内比较的射血分数平均绝对差异为2.6%。
开发了一种强大的心肌边缘检测技术，适用于常规临床应用。
