PUBS: Pulsatility-based segmentation of lumens conducting non-steady flow
PUBS: Pulsatility-based segmentation of lumens conducting non-steady flow
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DOI：
10.1002/mrm.10455
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发表时间：
2003-05-01
影响因子：
3.3
通讯作者：
Lee, SH
中科院分区：
文献类型：
--
作者：
Alperin, N;Lee, SH
动态速度编码相衬MRI（PC-MRI）技术正越来越多地用于量化脉动流的各种临床应用。研究表明，使用PC-MRI进行流量定量的可靠性似乎主要取决于管腔边界描绘的一致性。一种自动化的方法，利用空间和时间的信息已被开发，以提高准确性和再现性。该方法的准确性进行了评估，使用8毫米和5毫米直径的管腔在两个不同的流速的流量幻影。该方法的重现性进一步评价与动脉，静脉和脑脊液流量数据从人类受试者。将结果与不同技能水平的观察者手动获得的测量结果进行比较。手动获得的测量值始终小于基于搏动性分割（PUBS）方法获得的测量值。对于8 mm管腔，测量精度得到了显著提高。由熟练的观察者手动获得的高流量和低流量的平均管腔面积测量误差约为18%，分别降低至2.9%和4.8%。对于5 mm管腔，熟练的观察者低估了13%的管腔面积，而PUBS方法高估了28%的管腔面积。较小管腔的高估管腔面积测量值归因于部分容积效应。PUBS方法的测量变异性显著较小。使用新方法，观察者间测量变异性平均降低了四倍。(C)2003 Wiley-Liss，Inc.
Dynamic velocity-encoded phase-contrast MRI (PC-MRI) techniques are being used increasingly to quantify pulsatile flows for a variety of clinical applications. Studies suggest that the reliability of flow quantitation with PC-MRI appears to be dominated by the consistency in the delineation of the lumen boundary. An automated method that utilizes both spatial and temporal information has been developed for improved accuracy and reproducibility. The method's accuracy was evaluated using a flow phantom with 8- and 5-mm-diameter lumens at two different flow rates. The reproducibility of the method was further evaluated with arterial, venous, and cerebrospinal fluid flow data from human subjects. The results were compared with measurements obtained manually by observers of different skill levels. Measurement values obtained manually were consistently smaller than those obtained with the pulsatility-based segmentation (PUBS) method. For the 8-mm lumen, significant improvements in measurement accuracy were obtained. Average lumen area measurement errors of about 18% for the high and low flows, obtained manually by a skilled observer, were reduced to 2.9% and 4.8%, respectively. For the 5-mm lumen, the skilled observer underestimated the lumen area by 13%, while the PUBS method overestimated the lumen area by 28%. Overestimated lumen area measurements for the smaller lumen are attributed to the partial-volume effect. There was significantly less measurement variability with the PUBS method. An average fourfold reduction in interobserver measurement variability was obtained with the new method. (C) 2003 Wiley-Liss, Inc.