Impact of T2 decay on carotid artery wall thickness measurements.
Impact of T2 decay on carotid artery wall thickness measurements.
复制标题
T2 衰减对颈动脉壁厚度测量的影响。
DOI：
10.1002/jmri.23856
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Wasserman,BruceA
中科院分区：
文献类型：
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作者：
Qiao,Ye;Steinman,DavidA;Etesami,Maryam;Martinez-Marquese,Alex;Lakatta,EdwardG;Wasserman,BruceA
PurposeTo调查的影响T2松弛的颈动脉壁上的测量其thickness.Materials和MethodsThe颈总动脉壁成像使用自旋回波序列获得在四个回波时间（17毫秒至68毫秒）在65名参与者的VALIDATE研究的一部分。在分流器近端1.5 cm处横向于动脉采集图像。测量每个回波的平均壁厚、平均壁信号强度、管腔面积和外壁面积。还在来自第四次回波的图像上追踪轮廓，然后将其传播到来自先前回波的图像。使用来自第一次回波的图像重复这一过程。在四个回波时间的平均壁信号强度测量值拟合到单指数衰减曲线，以获得每组轮廓的平均T2弛豫时间。结果平均壁厚度随着回波时间的增加而减少，在第一次和最后一次回波时间（TE）采集的图像之间平均厚度减少8.6%。（TE 17 ms时为0.93 mm，TE 68 ms时为0.85 mm，P< 0.001）。当使用最后一次回波的较小轮廓时，颈动脉壁的平均T2弛豫时间减少了3%，其中不包括最外层（54.3 ± 7.6 ms vs 52.7 ± 6.6 ms，P= 0.03）。结论颈动脉壁厚度测量值随回波时间减少，正如最外层（即外膜）的快速T2弛豫时间所预期的那样。厚度测量需要较短的回波时间以包括外膜，外膜在斑块发展中起重要作用。J.磁共振Imaging 2013;37：1493-1498.© 2012 Wiley Periodicals，Inc.
PurposeTo investigate the impact of T2 relaxation of the carotid wall on measurements of its thickness.Materials and MethodsThe common carotid artery wall was imaged using a spin echo sequence acquired at four echo times (17 ms to 68 ms) in 65 participants as part of VALIDATE study. Images were acquired transverse to the artery 1.5 cm proximal to the flow divider. Mean wall thickness, mean wall signal intensity, lumen area, and outer wall area were measured for each echo. Contours were also traced on the image from the fourth echo and then propagated to the images from the preceding echoes. This was repeated using the image from the first echo. Mean wall signal intensity measurements at the four echo times were fit to a mono‐exponential decay curve to derive the mean T2 relaxation time for each set of contours.ResultsMean wall thickness decreased with increasing echo time, with an average thickness reduction of 8.6% between images acquired at the first and last echo times (TE) (0.93 mm at TE 17 ms versus 0.85 mm at TE 68 ms,P< 0.001). Average T2 relaxation time of the carotid wall decreased by 3% when the smaller contours from the last echo were used, which excluded the outer‐most layer (54.3 ± 7.6 ms versus 52.7 ± 6.6 ms,P= 0.03).ConclusionCarotid wall thickness measurements decrease with echo time as expected by the fast T2 relaxation time of the outer‐most layer, namely the adventitia. A short echo time is needed for thickness measurements to include adventitia, which plays an important role in plaque development. J. Magn. Reson. Imaging 2013;37:1493–1498. © 2012 Wiley Periodicals, Inc.