Intensity inhomogeneity correction for magnetic resonance imaging of human brain at 7T
Intensity inhomogeneity correction for magnetic resonance imaging of human brain at 7T
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DOI：
10.1118/1.4860954
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发表时间：
2014-02-01
期刊：
影响因子：
3.8
通讯作者：
Sasaki, Makoto
中科院分区：
文献类型：
--
作者：
Uwano, Ikuko;Kudo, Kohsuke;Sasaki, Makoto
目的：评价扩展版统一分割算法在7T MRI中对人脑各序列进行强度不均匀性校正的性能和效果。材料：采用7T MRI系统对10名健康志愿者进行4种不同序列（2D自旋回波[SE]、3D快速回波、2D快速衰减梯度回波和3D飞行时间）扫描。使用SPM8中的“New Segment”模块，在高斯平滑中使用四个不同值（120、90、60和30 mm）的半最大全宽度（FWHM）进行强度非均匀性校正。用变异系数（CV）评价整个脑白质信号的均匀性；比较皮层下和深部白质的平均信号强度，测量皮层下白质和灰质的对比。在原始图像和校正图像的最大强度投影（MIP）图像上测量透镜状纹状体（LSA）的长度。结果：在所有序列中，CV随FWHM值的减小而减小。皮层下和深部白质的平均信号强度差异也随着FWHM值的减小而减小。在所有FWHM值下，白质和灰质的对比保持不变。校正后的MIP图像的LSA长度明显大于原始MIP图像。结论：在不同的扫描序列中，SPM8可以成功地纠正7T MRI的强度不均匀性。(C) 2014年美国医学物理学家协会。
Purpose: To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm.Materials: Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the "New Segment" module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images.Results: In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images.Conclusions: Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences. (C) 2014 American Association of Physicists in Medicine.