室间孔的影像观察及其临床意义

Observation of the foramen of Monro on magnetic resonance imaging and its clinical significance

目的探讨室间孔的影像定位及其临床意义。方法对30例正常人头颅磁共振成像的室间孔进行观察,了解其位置、形态及大小;同时与脑积水及室间孔区域肿瘤患者的室间孔进行比较。结果室间孔位于大脑内侧、丘脑前端和穹窿之间,平均横径为2.8 mm,纵径为2.1 mm,双侧室间孔与第三脑室间形成一"Y"形结构。脑积水患者室间孔形态及大小变化非常明显,有时与第三脑室和侧脑室融为一体,形成"兔头征"。室间孔区域肿瘤患者室间孔因肿瘤位置和大小的不同而表现不一。结论室间孔在颅内的位置相对恒定,其位置、大小和形态的改变是颅内病变的重要征象;手术前应根据个体化的原则测量其大小及位置以决定手术的方案。

Objective To study the localization of the foramen of Monro on magnetic resonance image （MRI） and its clinical significance. Methods Cranial MRI was observed for 30 normal healthy subjects to study their location, shape and size of the foramen of Monro, as compared to those in 22 patients with hydrocephalus and 14 cases with tumor around their foramen. Results The the foramen of Monro is located between the fornix and the anterior part of thalamus in the normal healthy subjects, with a transverse diameter of 2.8 mm and a vertical diameter of 2. 1 mm in average on MRI. Y-shaped structure is formed between their bilateral the foramen of Monro and the 3rd cerebral ventricle. Very obvious changes in shape and size of the foramen of Monro can be observed in patients with hydrocephalus, which sometimes can integrated with the 3rd cerebral ventricle and lateral ventricle, forming a ＂rabbit-head sign＂, Meanwhile, imaging of the foramen of Monro varied in patients with tumor around the foramen, depending on its location and size. Conclusions The foramen of Monro has a relative constant position in the brain. Changes in its position, size and shape are important signs suggesting intracranial lesions. An individualized operation plan for a patient should be determined based on those changes.