Magnetization transfer from inhomogeneously broadened lines: A potential marker for myelin.
Magnetization transfer from inhomogeneously broadened lines: A potential marker for myelin.
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DOI：
10.1002/mrm.25174
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发表时间：
2015-02
影响因子：
3.3
通讯作者：
Alsop, David C.
中科院分区：
文献类型：
--
作者：
Varma, Gopal;Duhamel, Guillaume;de Bazelaire, Cedric;Alsop, David C.
目的：描述一种新的磁化转移成像方法，该方法相对于传统的磁化转移成像具有更高的特异性。实施磁化转移准备序列，其中所有射频功率集中在单个频率上，并且功率在正负频率之间均匀分配。用短的交变频率脉冲和连续照射的正弦调制都实现了双频饱和。准备后的图像用单次激发快速自旋回波序列采集。单频和双频制备应该达到类似的分子饱和，除了那些不均匀加宽的谱线。从单频图像中减去DUAL，得到不均匀MT(IHMT)图像。用不同的功率和频率在正常志愿者的脑内进行IHMT成像。(IHMT)方法显示了比传统MT更大的白质/灰质比率，以及头皮和其他无髓组织中信号的有效消除。IHMT超过白质完全松弛磁化强度的5%。在高频下观察到了广泛的频谱和轴突角度依赖的迹象，这与偶极加宽是一致的。IHMT显示了髓鞘特异性成像的前景。其物理机制和诊断敏感性值得进一步研究。
To characterize a new approach to magnetization transfer (MT) imaging with improved specificity for myelinated tissues relative to conventional MT. Magnetization transfer preparation sequences were implemented with all radiofrequency power centered on a single frequency and also with power evenly divided between positive and negative frequencies. Dual frequency saturation was achieved both with short, alternating frequency pulses and with sinusoidal modulation of continuous irradiation. Images following preparation were acquired with a single shot fast spin echo sequence. Single and dual frequency preparation should achieve similar saturation of molecules except for those with inhomogenously broadened lines. Inhomogenous MT (IHMT) images were generated by subtraction of dual from single frequency prepared images. IHMT imaging was performed with different power and frequency in the brains of normal volunteers. The (IHMT) method demonstrated a greater white/gray matter ratio than conventional MT and virtual elimination of signal in scalp and other unmyelinated tissues. IHMT exceeded 5% of the fully relaxed magnetization in white matter. A broad frequency spectrum and signs of axonal angular dependence at high frequency were observed that are consistent with dipolar broadening. IHMT shows promise for myelin specific imaging. Further study of physical mechanisms and diagnostic sensitivity are merited.
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影响因子：
3.3
作者：
Alsop, DC
通讯作者：
Alsop, DC
影响因子：
3.3
作者：
Gloor, M.;Scheffler, K.;Bieri, O.
通讯作者：
Bieri, O.
影响因子：
64.8
作者：
CHAN, SI;FEIGENSON, GW;SEITER, CHA
通讯作者：
SEITER, CHA
影响因子：
3.3
作者：
Scheidegger, Rachel;Vinogradov, Elena;Alsop, David C.
通讯作者：
Alsop, David C.
影响因子：
4.4
作者：
Schmierer, Klaus;Tozer, Daniel J;Scaravilli, Francesco;Altmann, Daniel R;Barker, Gareth J;Tofts, Paul S;Miller, David H
通讯作者：
Miller, David H