Caulo M, Briganti C, Mattei P A, Perfetti B, Ferretti A, Romani G L, Tartaro A, Colosimo C
Institute Advanced Biomedical Technologies of the Department of Clinical Sciences and Bioimaging, University G. d'Annunzio, Chieti, Italy.
AJNR Am J Neuroradiol. 2007 Sep;28(8):1480-5. doi: 10.3174/ajnr.A0597.
The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a new classification with 5 morphologic variants of the HMC in the axial plane (omega, medially asymmetric epsilon, epsilon, laterally asymmetric epsilon, and null).
Structural brain MR images were obtained from 257 right-handed healthy subjects (143 men and 114 women; mean age, 23.1 +/- 1.1 years) via a Talairach space transformed 3D magnetization-prepared rapid acquisition of gradient echo sequence. The frequencies of the different HMC variants were reported for hemisphere and sex.
The new variants of the HMC (medially asymmetric epsilon, laterally asymmetric epsilon, and null) were observed in 2.9%, 7.0%, and 1.8% of the hemispheres, respectively. Statistically significant sex differences were observed: The epsilon variant was twice as frequent in men, and an interhemispheric concordance for morphologic variants was observed only for women.
The large study population permitted the description of a new morphologic classification that included 3 new variants of the HMC. This new morphologic classification should facilitate the identification of the precentral gyrus in subsequent studies and in everyday practice.
在手运动皮层（HMC）的CT和MR轴位图像中，传统上认为其呈ω形或ε形。本研究旨在利用MR成像和Talairach标准化，在年龄和利手情况均一的大样本群体中，基于性别模型评估一种新的分类方法，该方法将HMC在轴位平面分为5种形态学变体（ω形、内侧不对称ε形、ε形、外侧不对称ε形和无形态）。
通过Talairach空间变换的三维磁化准备快速梯度回波序列，从257名右利手健康受试者（143名男性和114名女性；平均年龄23.1±1.1岁）获取脑结构MR图像。报告不同HMC变体在半球和性别的出现频率。
分别在2.9%、7.0%和1.8%的半球中观察到HMC的新变体（内侧不对称ε形、外侧不对称ε形和无形态）。观察到显著的性别差异：ε变体在男性中的出现频率是女性的两倍，仅在女性中观察到形态学变体的半球间一致性。
大样本研究群体使得能够描述一种新的形态学分类，其中包括HMC的3种新变体。这种新的形态学分类应有助于在后续研究和日常实践中识别中央前回。
