目的：分析原发性低颅压综合征的临床、MRI特征性表现及定量指标的改变，提高对本病的认识和诊断准确率。方法：回顾性分析原发性低颅压综合征24例，全部行MRI平扫及增强扫描，5例加扫MRV。定量指标包括硬脑膜厚度、脑垂体高度、第三脑室横径、中央沟宽度、乳头体脑桥间距及窦汇的宽度，分别进行测量分析。结果：所有病例均有体位性头痛，腰椎穿刺脑脊液压力为0～60 mmH2O，MRI增强扫描均显示硬脑膜弥漫、对称性线状强化。硬脑膜厚度、脑垂体高度与脑脊液压力呈负相关（P＜0.05），第三脑室横径、中央沟宽度、乳头体脑桥间距与脑脊液压力呈正相关（P＜0.05），窦汇宽度与脑脊液压力无关（P＞0.05）。结论：原发性低颅压综合征临床及MRI表现具有一定特征性，硬脑膜增厚、垂体增大、脑室及脑沟变窄、脑下垂程度在临床治疗中可作为客观的评价指标。

Objective: To analyze the clinical and MRI quantitative changes of primary intracranial hypotension syndrome, and to improve the understanding and diagnostic accuracy of the disease. Methods: Twenty-four cases of primary intracranial hypotension syndrome were retrospectively analyzed. All the patients underwent MRI plain scan and enhanced scan, of which 5 cases were examined by MRV. Quantitative measurements included dural thickness, pituitary height, transverse diameter of the third ventricle, the width of the central sulcus, the distance between the body of che pons and the width of the torcular herophili. Results: All cases had postural headache, lumbar puncture cerebrospinal fluid pressure 0～60 mmH2O, MRI enhanced scan showed diffuse and symmetrical linear enhancement. Dural thickness, pituitary height were negatively correlated with cerebrospinal fluid pressure(P<0.05), the third ventricle diameter, central sulcus width, mammillary body pons spacing were positively correlated with cerebrospinal fluid pressure(P<0.05), and the width of torcular herophili was not correlated with cerebrospinal fluid pressure(P>0.05). Conclusion: The clinical and MRI features of primary intracranial hypotension syndrome have some characteristics, the dural thickening, pituitary enlargement, ventricle, cerebral sulcus narrowing and cerebral ptosis degree can be used as objective evaluation indexes in clinical treatment.