前瞻性运动校正可实现 7T 时最高分辨率的时间飞跃血管造影。
Prospective motion correction enables highest resolution time-of-flight angiography at 7T.
机构信息
Department of Biomedical Magnetic Resonance, Institute of Experimental Physics, Otto-von-Guericke-University, Magdeburg, Germany.
Chair for Healthcare Telematics and Medical Engineering, Otto-von-Guericke-University, Magdeburg, Germany.
出版信息
Magn Reson Med. 2018 Jul;80(1):248-258. doi: 10.1002/mrm.27033. Epub 2017 Dec 11.
PURPOSE
Higher magnetic field strengths enable time-of-flight (TOF) angiography with higher resolution to depict small-vessel pathologies. However, this potential is limited by the subject's ability to remain motionless. Even small-scale, involuntary motion can degrade vessel depiction, thus limiting the effective resolution. The aim of this study was to overcome this resolution limit by deploying prospectively motion-corrected (PMC) TOF.
METHODS
An optical, marker-based, in-bore tracking system was used to update the imaging volume prospectively according to the subject's head motion. PMC TOF was evaluated in 12 healthy, cooperative subjects at isotropic resolution of up to 150 μm. Image quality was assessed qualitatively through reader rating and quantitatively with the average edge-strength metric.
RESULTS
PMC significantly increased the average edge strength and qualitatively improved the vessel depiction in nine out of 11 cases. Image quality was never degraded by motion correction. PMC also enabled acquisition of the highest resolution human brain in vivo TOF angiography to date.
CONCLUSION
With PMC enabled, high-resolution TOF is able to visualize brain vasculature beyond the effective resolution limit. Magn Reson Med 80:248-258, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
目的
更高的磁场强度可以实现更高分辨率的时间飞越（TOF）血管造影，以描绘小血管病变。然而，这种潜力受到受检者保持静止不动的能力的限制。即使是微小的、无意识的运动也会降低血管的清晰度，从而限制有效分辨率。本研究的目的是通过采用前瞻性运动校正（PMC）TOF 来克服这一分辨率限制。
方法
采用光学、基于标记的腔内跟踪系统，根据受检者的头部运动前瞻性地更新成像体积。在各向同性分辨率高达 150μm 的情况下，对 12 名健康、合作的受试者进行了 PMC TOF 的评估。通过读者评分进行定性评估，并通过平均边缘强度指标进行定量评估。
结果
在 11 例中有 9 例，PMC 显著提高了平均边缘强度，并在定性上改善了血管显示。运动校正从未降低图像质量。PMC 还实现了迄今为止在活体人体中采集到的最高分辨率的 TOF 血管造影。
结论
启用 PMC 后，高分辨率 TOF 能够可视化超出有效分辨率限制的脑血管。磁共振医学 80:248-258,2018。© 2017 国际磁共振学会。
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