Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.
Magn Reson Med. 2011 Nov;66(5):1346-52. doi: 10.1002/mrm.22928. Epub 2011 May 23.
Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons-including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools k(mf) . This study describes the first implementation of the selective inversion recovery quantitative magnetization transfer method on a clinical 3.0-T scanner in human brain in vivo. Selective inversion recovery data were acquired at 16 different inversion times in nine healthy subjects and two patients with relapsing remitting multiple sclerosis. Data were collected using a fast spin-echo readout and reduced repetition time, resulting in an acquisition time of 4 min for a single slice. In healthy subjects, excellent intersubject and intrasubject reproducibilities (assessed via repeated measures) were demonstrated. Furthermore, PSR values in white (mean ± SD = 11.4 ± 1.2%) and gray matter (7.5 ± 0.7%) were consistent with previously reported values, while k(mf) values were approximately 2-fold slower in both white (11 ± 2 s(-1) ) and gray matter (15 ± 6 s(-1) ). In relapsing remitting multiple sclerosis patients, quantitative magnetization transfer indices were sensitive to pathological changes in lesions and in normal appearing white matter.
定量磁化转移成像是一种可以描述自由水质子和不可动的大分子质子之间相互作用的方法，包括大分子与自由池大小比（PSR）和池间磁化转移率（k(mf)）。本研究首次在临床 3.0T 扫描仪上对人体大脑进行了选择性反转恢复定量磁化转移方法的应用。在 9 名健康受试者和 2 名复发缓解型多发性硬化症患者中，采集了 16 种不同反转时间的选择性反转恢复数据。使用快速自旋回波读出和缩短重复时间进行数据采集，单次切片的采集时间为 4 分钟。在健康受试者中，通过重复测量评估，显示出良好的个体间和个体内可重复性。此外，白质（均值±标准差=11.4±1.2%）和灰质（7.5±0.7%）的 PSR 值与之前报道的值一致，而白质（11±2 s(-1)）和灰质（15±6 s(-1)）的 k(mf)值则大约慢了两倍。在复发缓解型多发性硬化症患者中，定量磁化转移指数对病变和正常表现的白质中的病变变化敏感。
