Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Magn Reson Med. 2018 Feb;79(2):806-814. doi: 10.1002/mrm.26736. Epub 2017 May 5.
The ability to evaluate pathological changes in the spinal cord in multiple sclerosis (MS) is limited because T - and T -w MRI imaging are not sensitive to biochemical changes in vivo. Amide proton transfer (APT) chemical exchange saturation transfer (CEST) can indirectly detect amide protons associated with proteins and peptides, potentially providing more pathological specificity. Here, we implement APT CEST in the cervical spinal cord of healthy and MS cohorts at 3T.
APT CEST of the cervical spinal cord was obtained in a cohort of 10 controls and 10 MS patients using a novel respiratory correction methodology. APT was quantified using two methods: 1) APT , based off the conventional magnetization transfer ratio asymmetry, and 2) ΔAPT, a spatial characterization of APT changes in MS patients relative to the controls.
Respiratory correction yielded highly reproducible z-spectra in white matter (intraclass correlation coefficient = 0.82). APT signals in normal-appearing white matter (NAWM) of MS patients were significantly different from healthy controls (P = 0.04), whereas ΔAPT of MS patients highlighted large APT differences in NAWM.
Respiration correction in the spinal cord is necessary to accurately quantify APT CEST, which can provide unique biochemical information regarding disease processes within the spinal cord. Magn Reson Med 79:806-814, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
由于 T1 和 T2 加权 MRI 成像对体内生化变化不敏感，因此评估多发性硬化症（MS）脊髓病变的能力有限。酰胺质子转移（APT）化学交换饱和传递（CEST）可以间接检测与蛋白质和肽相关的酰胺质子，从而提供更具病理特异性的方法。在这里，我们在 3T 下对健康对照组和 MS 队列的颈脊髓实施 APT CEST。
使用一种新的呼吸校正方法，在 10 名对照者和 10 名 MS 患者的队列中获得颈脊髓的 APT CEST。使用两种方法定量 APT：1）APT，基于传统的磁化转移比不对称性，2）ΔAPT，用于表征 MS 患者相对于对照组的 APT 变化的空间特征。
呼吸校正方法在白质中产生了高度可重复的 z 谱（组内相关系数=0.82）。MS 患者正常表现白质（NAWM）中的 APT 信号与健康对照组明显不同（P=0.04），而 MS 患者的 ΔAPT 则突出了 NAWM 中 APT 的巨大差异。
脊髓的呼吸校正对于准确量化 APT CEST 是必要的，它可以提供有关脊髓内疾病过程的独特生化信息。磁共振医学 79:806-814, 2018。©2017 国际磁共振学会。
