Dyverfeldt Petter, Ebbers Tino, Länne Toste
Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Media and Information Technology, Department of Science and Technology/Swedish e-Science Research Centre (SeRC), Linköping University, Linköping, Sweden.
Magn Reson Imaging. 2014 Dec;32(10):1266-71. doi: 10.1016/j.mri.2014.08.021. Epub 2014 Aug 27.
The objective of this study was to compare multiple methods for estimation of PWV from 4D flow MRI velocity data and to investigate if 4D flow MRI-based PWV estimation with piecewise linear regression modeling of travel-distance vs. travel time is sufficient to discern age-related regional differences in PWV.
4D flow MRI velocity data were acquired in 8 young and 8 older (age: 23±2 vs. 58±2 years old) normal volunteers. Travel-time and travel-distance were measured throughout the aorta and piecewise linear regression was used to measure global PWV in the descending aorta and regional PWV in three equally sized segments between the top of the aortic arch and the renal arteries. Six different methods for extracting travel-time were compared.
Methods for estimation of travel-time that use information about the whole flow waveform systematically overestimate PWV when compared to methods restricted to the upslope-portion of the waveforms (p<0.05). In terms of regional PWV, a significant interaction was found between age and location (p<0.05). The age-related differences in regional PWV were greater in the proximal compared to distal descending aorta.
Care must be taken as different classes of methods for the estimation of travel-time produce different results. 4D flow MRI-based PWV estimation with piecewise linear regression modeling of travel-distance vs. travel time can discern age-related differences in regional PWV well in line with previously reported data.
本研究的目的是比较从4D流动磁共振成像（MRI）速度数据估计脉搏波速度（PWV）的多种方法，并研究基于4D流动MRI的PWV估计（采用行程距离与行程时间的分段线性回归模型）是否足以识别与年龄相关的PWV区域差异。
在8名年轻（年龄：23±2岁）和8名年长（年龄：58±2岁）的正常志愿者中采集4D流动MRI速度数据。测量整个主动脉的行程时间和行程距离，并采用分段线性回归测量降主动脉的整体PWV以及主动脉弓顶部与肾动脉之间三个等大小节段的局部PWV。比较了六种不同的提取行程时间的方法。
与仅限于波形上升段的方法相比，系统地利用整个血流波形信息估计行程时间的方法会系统性地高估PWV（p<0.05）。在局部PWV方面，发现年龄与位置之间存在显著交互作用（p<0.05）。降主动脉近端的局部PWV与年龄相关的差异大于远端。
必须注意，因为不同类别的行程时间估计方法会产生不同的结果。基于4D流动MRI的PWV估计（采用行程距离与行程时间的分段线性回归模型）能够很好地识别与年龄相关的局部PWV差异，与先前报道的数据一致。
