正常中国成人MRI海马结构体积测定

目的讨论磁共振海马结构（ｈｉｐｐｏｃａｍｐａｌｆｏｒｍａｔｉｏｎ，ＨＦ）体积测量方法，制订正常成人ＨＦ体积范围。材料与方法５２例正常成人做垂直于ＨＦ长轴的倾斜冠状位自旋回波（ＳＥ）序列Ｔ１加权像，其中２５例还做相同位置的三维磁化准备快速梯度回波（ｔｈｒｅｅｄｉｍｅｎｓｉｏｎａｌｍａｇｎｅｔｉｚａｔｉｏｎｐｒｅ－ｐａｒｅｄｒａｐｉｄｇｒａｄｉｅｎｔｅｃｈｏ，３ＤＭＰＲＡＧＥ）序列Ｔ１加权像。体积测量后界定在后连合，手工勾画出ＨＦ边缘获得面积，并依此获得ＨＦ体积。结果正常成人ＨＦ体积与年龄无关，在性别、利手之间均无显著性差异，右侧下限为２．６２ｃｍ３，左侧为２．４８ｃｍ３。３ＤＭＰＲＡＧＥ序列较ＳＥ序列的对比度、对比噪声比、对比伪影比高，而两者信噪比无显著性差异。结论后连合作为ＨＦ体积测定后界较合适，ＨＦ正常值的制订有利于颞叶癫痫的定侧。３ＤＭＰＲＡＧＥ序列较ＳＥ序列用于ＨＦ体积测定更为优越

Volumetric measurement of hippocampal formation using MRI in the normal Chinese adults

Purpose To discuss the method of volumetry of hipocampal formation (HF) with MRI and establish the volume range of HF in normal adults. Materials and methods Fifty two normal adults underwent MR examinations using oblique coronal spin echo(SE) T 1WI with the imaging plane perpendicular to the long axis of hippocampus.Additionally, 25 of the 52 subjects were also studied using three dimensional magnetization prepared rapid gradient echo(3D MPRAGE) T 1WI at the same position. The posterior margin of hippocampal volumetry was defined by the plane which intersected the posterior commissure.The boundaries of HF was outlined manually to obtain the area of every section and the volume of HF. Results The lower limit of right HF volume was 2.62 cm 3,and the left 2.48 cm 3,it was not correlated with age and no significant difference was observed regarding sex and handedness. 3D MPRAGE had better contrast, contrast/noise and contrast/artifact than SE and yet with similar signal/noise(S/N). Conclusion It was more appropriate to define the posterior commissure as the posterior margin of HF volumetry, the determination of volume range of HF was helpful in lateralization of temporal lobe epilepsy(TLE). 3D MPRAGE was superior to SE in the volumetry of HF.