腦脊髓液(Cerebrospinal Fluid, CSF)容量不足是自發性顱內低壓(Spontaneous Intracranial Hypotension, SIH)的發病關鍵因素，目前很少針對SIH 患者實施全身性腦脊髓液容積量化研究的相關文獻報告。本研究利用統計模型熵度量門檻值法(Entropy Thresholding Algorithm)及分水嶺切割演算法(Watershed Algorithm)分析顱部及全脊椎部位強烈T2 權重磁振影像，將影像中CSF 區域萃取量化，共15 位SIH 患者及20 位健康受試者MR 影像被納入研究。分別對15 位SIH 患者治療前後進行顱部與脊椎腦脊髓液進行萃取，治療前全身CSF 平均容積中位數為206.2mL，治療後為253.4 mL，p 值為0.002。二十名健康受試者全身CSF 容積中位數為247.96 mL。從數據分析，發病時無論是顱部或是脊椎之CSF 含量皆低於健康者受試者，硬膜外血液貼片(epidural blood patch, EBP)治療後之SIH 患者在顱部及脊椎CSF 容積皆有增加，與健康人CSF 容積相比無統計學上之差異，p 值為0.003。

At present, the medical community has concluded that the lack of cerebrospinal fluid capacity is a key factor in the SIH. At present, there is few literature on the quantitative study of systemic cerebrospinal fluid volume in SIH patients. In the experiment, we attempted to accurately and reliably assess total CSF volume using a statistical model of Entropy Thresholding algorithm and Watershed algorithm to extract of whole-body CSF voxels from heavy T2-weighted imaging MRI. A total of fifteen SIH patients and twenty healthy subjects with MR images were included in the analysis. 15 patients with SIH were enrolled in the whole-body CSF before and after treatment. The median volume of CSF before treatment was 206.2 ml, and 253.4 ml after treatment, p value is 0.002. The median CSF volume of 20 healthy subjects was 247.96 ml. From the data analysis, the CSF content of the whole body was lower than that of healthy subjects at the time of onset. The SIH patients after EBP replenishment treatment increased the volume of CSF compared with the onset of the brain or the spine. There was also no statistical difference in the CSF volume after replenishment, p value is 0.003.