【作者】 秦毅；

【导师】 张敬； 李金亭；

【作者基本信息】 天津医科大学 ， 影像医学与核医学， 2010， 硕士

【摘要】 三维双回波稳态水激发序列在面神经成像中的应用一、3D-DESSwe序列显示面神经全长目的探讨三维双回波稳态水激发(3D-DESSwe)序列对面神经成像的应用价值。方法根据3D-DESS序列的数学公式,采用Matlab7.1 (MathWorks, Natick, MA)软件,模拟并选择该序列的最佳扫描参数,以便在最短时间获得最佳信噪比和对比度。采用3D-DESSwe序列的最佳参数对15名健康志愿者行面神经扫描,对原始图像进行多平面重组(MPR)及薄层最大强度投影(MIP)。所得后处理图像由两位放射科医生参照格氏解剖学图谱对图像质量和面神经显示情况进行评估：2分：图像均匀,面神经显示清晰；1分：图像局部欠均匀,面神经显示模糊；0分：图像不均匀,无法显示面神经。结果所有志愿者两侧面神经均获得清晰显示,面神经与周围结构对比明显,所得图像评分均为2分。脑池段面神经呈高信号,其周围流动的脑脊液呈低信号；内听道段面神经呈相对低信号,内听道内流动受限的脑脊液呈高信号；迷路段、鼓室段、乳突段及颅外段面神经呈高信号,周围骨质、软组织呈低信号,可显示部分面神经分支。腮腺导管内的液体呈高信号。结论应用3D-DESSwe序列可以清晰显示各段面神经。二、3D-DESSwe序列显示腮腺段面神经目的探讨3D-DESSwe序列显示腮腺段面神经分支的价值。方法采用第一部分获得的3D-DESSwe序列的最佳扫描参数,在1.5T MR上对18例健康志愿者腮腺段面神经主干及其分支进行扫描。沿腮腺段面神经走行方向进行MPR和MIP重建。所得后处理图像由两位放射科医生参照格氏解剖学图谱,对腮腺段面神经主干及其分支的显示情况进行评判,遇有不同意见协商解决。结果在3D-DESSwe序列后处理图像中,腮腺段面神经主干的显示率为100%,面神经颈面干的显示率为94.4%,颞面干的显示率为55.6%。腮腺导管在3D-DESSwe序列上信号稍高于面神经。结论3D-DESSwe序列可以显示腮腺段面神经主干及其主要分支,也能显示腮腺导管,有助于术前评估腮腺肿瘤和面神经的关系。更多还原

【Abstract】 Objective To assess the value of 3D double echo steady state (DESS) with water excitation MR sequence in depicting the normal anatomy of facial nerve. Methods To optimize the image contrast, computer simulations of the 3D-DESS sequence were first carried out through the code written in Matlab 7.1 (MathWorks, Natick, MA). The relationship between the flip angle(FA) and signal to noise ratio(SNR) was explored, and the optimum parameters for the best contrast were obtained.3D-DESSwe MR sequence with the optimum parameters was performed in 15 healthy volunteers on a 1.5-T MR unit. The 3D datasets were reconstructed in relation to the course of the facial nerve by using the multi-planar reconstruction (MPR) and thin slice maximum intensity projection (MIP) programs. Two radiologists analyzed the images in collaboration and recorded on an arbitrary scale of 0—2 grades by comparing with anatomical textbook diagrams. (2 grades: homogeneity and facial nerve identified with certainty; 1 grade:mild inhomogeneity and facial nerve probably identified; 0:severe inhomogeneity and facial nerve not identified). Results In all subjects,3D DESS with water excitation images provided reliable definition of the normal facial nerve anatomy bilaterally and high contrast between the facial nerve and adjacent structures were obtained(score=2). The cisternal segment of facial nerve showed high signal intensity while the moving CSF flow surrounding it showed low signal intensity; the internal auditory canal (IAC) segment of facial nerve showed relatively low signal intensity while the stationary CSF surrounding it showed high signal intensity. The labyrinthine, tympanic, mastoid and extracranial segments of facial nerve showed high signal intensity while the bone and soft tissue surrounding it showed low signal intensity, and branches of intraparotid facial nerve can be demonstrated. And the fluid in parotid ducts showed high signal intensity. Conclusion Various sections of the normal facial nerve can be clearly displayed by 3D-DESSwe sequence. Objective:To explore the usefulness of 3D-DESSwe sequence that dipicts the normal anantomy of the intraparotid facial nerve. Methods:3D-DESSwe sequence with the optimum parameters was performed in 18 healthy volunteers on a 1.5-T MR unit. The data sets from the 3D-DESS sequence were reconstructed in multi-oblique planes oriented in relation to the course of intraparotid facial nerve. The reconstructed images were compared with anatomical textbook diagrams by two radiologists. Each radiologist made initial evaluations independently, and any disagreements regarding final conclusions were resolved by consensus. Results:The main trunks and cervicofacial and temporofacial divisions of the facial nerves were identified in 100%, 94.4% and 55.6%, respectively by using the 3D-DESSwe sequence. The signal intensity of the parotid ducts is slightly higher than the facial nerve in the 3D-DESSwe imaging. Conclusions:The anatomy of intraparotid facial nerve and its main branches can be depicted by using the 3D-DESSwe sequence, and the parotid dusts can also be displayed. This technique may be useful for preoperative evaluation of the relationship between the tumour and facial nerve in the parotid gland.更多还原