Papinutto Nico, Schlaeger Regina, Panara Valentina, Caverzasi Eduardo, Ahn Sinyeob, Johnson Kevin J, Zhu Alyssa H, Stern William A, Laub Gerhard, Hauser Stephen L, Henry Roland G
Department of Neurology, University of California San Francisco, San Francisco, California, USA.
Department of Neurology, University of Basel, Basel, Switzerland.
J Magn Reson Imaging. 2015 Sep;42(3):698-708. doi: 10.1002/jmri.24819. Epub 2014 Dec 8.
To present and assess a procedure for measurement of spinal cord total cross-sectional areas (TCA) and gray matter (GM) areas based on phase-sensitive inversion recovery imaging (PSIR). In vivo assessment of spinal cord GM and white matter (WM) could become pivotal to study various neurological diseases, but it is challenging because of insufficient GM/WM contrast provided by conventional magnetic resonance imaging (MRI).
We acquired 2D PSIR images at 3T at each disc level of the spinal axis in 10 healthy subjects and measured TCA, cord diameters, WM and GM areas, and GM area/TCA ratios. Second, we investigated 32 healthy subjects at four selected levels (C2-C3, C3-C4, T8-T9, T9-T10, total acquisition time <8 min) and generated normative reference values of TCA and GM areas. We assessed test-retest, intra- and interoperator reliability of the acquisition strategy, and measurement steps.
The measurement procedure based on 2D PSIR imaging allowed TCA and GM area assessments along the entire spinal cord axis. The tests we performed revealed high test-retest/intraoperator reliability (mean coefficient of variation [COV] at C2-C3: TCA = 0.41%, GM area = 2.75%) and interoperator reliability of the measurements (mean COV on the 4 levels: TCA = 0.44%, GM area = 4.20%; mean intraclass correlation coefficient: TCA = 0.998, GM area = 0.906).
2D PSIR allows reliable in vivo assessment of spinal cord TCA, GM, and WM areas in clinically feasible acquisition times. The area measurements presented here are in agreement with previous MRI and postmortem studies.
介绍并评估一种基于相位敏感反转恢复成像（PSIR）测量脊髓总横截面积（TCA）和灰质（GM）面积的方法。脊髓GM和白质（WM）的活体评估对于研究各种神经系统疾病可能至关重要，但由于传统磁共振成像（MRI）提供的GM/WM对比度不足，这具有挑战性。
我们在10名健康受试者的脊柱轴每个椎间盘水平处采集了3T的二维PSIR图像，并测量了TCA、脊髓直径、WM和GM面积以及GM面积/TCA比值。其次，我们在四个选定水平（C2-C3、C3-C4、T8-T9、T9-T10，总采集时间<8分钟）对32名健康受试者进行了研究，并生成了TCA和GM面积的正常参考值。我们评估了采集策略和测量步骤的重测、操作者内和操作者间的可靠性。
基于二维PSIR成像的测量程序允许沿整个脊髓轴评估TCA和GM面积。我们进行的测试显示出高重测/操作者内可靠性（C2-C3处的平均变异系数[COV]：TCA = 0.41%，GM面积 = 2.75%）以及测量的操作者间可靠性（4个水平上的平均COV：TCA = 0.44%，GM面积 = 4.20%；平均组内相关系数：TCA = 0.998，GM面积 = 0.906）。
二维PSIR能够在临床可行的采集时间内可靠地对脊髓TCA、GM和WM面积进行活体评估。此处呈现的面积测量结果与先前的MRI和尸检研究一致。
