Coronary flow and flow reserve in canines using MR phase difference and complex difference processing.
Coronary flow and flow reserve in canines using MR phase difference and complex difference processing.
复制标题
使用 MR 相位差和复差处理来研究犬科动物的冠状动脉血流和血流储备。
DOI：
10.1002/mrm.1910400503
复制
发表时间：
1998
影响因子：
3.3
通讯作者：
Mistretta,CA
中科院分区：
文献类型：
--
作者：
Wedding,KL;Grist,TM;Folts,JD;Maalej,N;Vigen,KK;Peters,DC;Osman,H;Mistretta,CA
冠状动脉疾病仍然是美国成年人死亡的主要原因。磁共振成像 (MR) 通过无创地提供广泛的解剖和生理信息，有可能极大地影响心脏病的诊断。先前的研究表明，冠状动脉血流是完整检查的一个组成部分，可以在体内准确测量左前降支动脉。当前的工作以通过时超声作为标准，验证了犬回旋动脉的 MR 血流测量。回旋动脉经历更大的平面内运动，并且是对流量测量精度的更严格的测试。这项工作还比较了处理 MR 速度数据的两种方法，即相位差和复数差分技术，并检查了动物验证模型中存在的误差来源。具有 30% 幅度阈值的相位差处理与平均超声流量值最匹配（30% PD = 1.04 × US + 1.49，r= 0.94），但它对血管边界识别非常敏感。尽管存在系统低估，但复杂的差分过程对血管边界识别不太敏感，并且与传播时间超声相关性良好。造成差异的原因有多种可能，包括超声标准的可变性、MR 图像的低信噪比、MR 技术对血管边界识别的敏感性以及图像中的运动伪影。
Coronary artery disease continues to be the leading cause of death for adults in the United States. Magnetic resonance imaging (MR) has the potential to dramatically impact the diagnosis of heart disease by noninvasively providing a wide range of anatomic and physiologic information. Previous re search has shown that coronary flow, one component of a complete examination, can be accurately measured in the left anterior descending arteryin vivaThe current work validates MR flow measurements in canine circumflex arteries using transit time ultrasound as a standard. The circumflex artery experiences greater in‐plane motion and is a more stringent test for flow measurement accuracy. This work also com pares two methods of processing MR velocity data, phase difference and complex difference techniques, and examines the sources of error present in the animal validation model. Phase difference processing with a 30% magnitude threshold best matched the mean ultrasound flow values (30% PD = 1.04 × US + 1.49,r= 0.94), but it was very sensitive to vessel boundary identification. The complex difference process was less sensitive to vessel boundary identification and correlated well with the transit time ultrasound despite systematic un‐derestimations. The reasons for the discrepancies are shown to stem from a number of possible sources including variabil ity of the ultrasound standard, low signal‐to‐noise ratios in the MR images, sensitivity of the MR technique to vessel bound ary identification, and motion artifacts in the images.