Shapiro R, Galloway S J, Shapiro M D
AJR Am J Roentgenol. 1986 Oct;147(4):753-6. doi: 10.2214/ajr.147.4.753.
Normal cerebral asymmetry, well-known to neuroradiologists, is not widely recognized by radiologists in general. In our review of CT brain scans, 31 of 300 patients with a negative neurologic examination and no history of birth injury, head trauma, or seizure had recognizable asymmetry of the frontal horns of the lateral ventricles. The right frontal horn and the right cerebral hemispheres were larger than the left twice as often as left were larger than right. The right frontal lobe was wider than the left in 44% of patients and extended as far anteriorly or more anteriorly than the left in 22% of patients. The right central hemispheric mass tended to be wider than the left, resulting in slight displacement of the pineal gland to the left, in approximately 45% of cases. The posterior end of the left Sylvian fissure projected farther posteriorly in 10% of the patients. Occipital petalia and a more posterior position of the calcified glomus of the choroid plexus of the lateral ventricle were both common on the left side of 56%. Earlier studies of the brain by other methods have also shown asymmetry. An awareness of these anatomic asymmetries in normal individuals should preclude the erroneous diagnosis of an atropic or mass lesion.
正常的脑不对称现象，神经放射科医生熟知，但一般放射科医生并未广泛认识到。在我们对脑部CT扫描的回顾中，300例神经系统检查阴性且无出生损伤、头部外伤或癫痫病史的患者中，31例存在侧脑室额角可识别的不对称。右侧额角和右侧大脑半球比左侧大的情况是左侧比右侧大的两倍。44%的患者右侧额叶比左侧宽，22%的患者右侧额叶向前延伸的距离与左侧相同或比左侧更远。约45%的病例中，右侧大脑半球中部的肿块往往比左侧宽，导致松果体轻微向左移位。10%的患者左侧外侧裂后端向后延伸更远。枕叶花瓣状结构以及侧脑室脉络丛钙化球更靠后的位置在左侧更为常见，占56%。其他方法对大脑的早期研究也显示出不对称。了解正常个体中的这些解剖学不对称应可避免对萎缩性或占位性病变的错误诊断。
