磁共振成像原理與應(yīng)用介紹_圖文

1、 Slice location and orientation BOLD-fMRI, GE-EPI, orbitofrontal cortex, slice location 101 Voxel size Influence of the voxel size 7T Siemens 102 matrix:80×80 3×3×3 mm3 27 ml matrix:128×102 2×2×2 mm3 8 ml matrix: 160×160 1.4×1.4×1.4 mm3 2.7 ml matrix:192&

2、#215;192 1.1×1.1×1.1 mm3 1.3 ml 被試的頭部位置 Deichmann, NI, 19(2003 430 Courtesy of Dr O. Speck, Otto-von-Guericke Universität Magdeburg, Germany Other artifacts When using a multi-channel Coil Uncombined Coil Images 103 Location: 3D anatomical images （） A Axial image. FOV placed in center

3、 to avoid side-to-side wrap. B Sagittal image. FOV placed anterior to avoid nose wrap. C Coronal image. FOV placed to assure top of the brain is covered. 104 Surface Coil D 建議用 Sagittal掃 描 Location: DTI （） Full BRAIN coverage and slice in transverse orientation 105 Location: fMRI （） If the slice dis

4、tances are too small, the signals of adjacent slices affect one another. This effect, called CROSS-TALK, also changes the T1 contrast. Select an interleaved sequence will reduce the disadvantages inherent in small slice distances. 106 The acquisition stack should be placed just above the most superi

5、or point in the brain and should fully cover the cerebellum as well as all brain in the lateral and the anterior to posterior planes. If extra transverse slices are required to achieve this coverage please acquire those slices. 3 13 2 12 1 AC-PC line, or other orientations depending on your study; anterior commissure, posterior commissure O O Checking list MRI 圖像質(zhì)量檢測(checking list 檢查圖像完整性 檢查圖像的均勻程度 檢查圖像的幾何形變 檢查CSF/WM/GM的對比度 檢查偽影情況