Magnetic resonance imaging of pulsatile flow of cerebrospinal fluid and its relation to intracranial pressure

已经表明，在颅腔中流动的脑脊液（cSF）在磁共振（MR）图像上失去其信号。这被称为“信号-空隙现象（SVP）"。我们注意到SVP与颅内压（ICP）水平之间存在一定的关系。对25例脑积水患者的MRI图像进行了分析，发现SVP在颅内压正常的脑积水患者中多见，而在颅内压增高的脑积水患者中（如幕上肿瘤患者）则少见。这些研究表明，尾侧脑脊液流速峰值出现在心电图R波后200毫秒内，其余9例患者在心电图触发NR显像的基础上加测ICP，其最大流速出现的时间与ICP正常者的ICP波最高峰出现的时间相吻合。而在高颅内压患者中，这些时间点并不一致，通过观察脑脊液信号强度的变化，有可能无创地估计颅内压。

It has been shown that cerebrospinal fluid (cSF) flowing in the cranial cavity loses its signal on magnetic resonance (MR) images. This is termed the "signal-voidphenomenon (SVP)". We noted some relationships between the SVP and the level of the intracranial pressure (ICP).In 289 neurosurgecal patients, the MR studies focused on the presence of the SVP. The SVP was observed frequently in the MR images of patients with C M ommunicating hydrocephalus who showed normal intracranial pressure (ICP), whereas the svp was observed rarely in patients with highICP, such as those with a supratentorial tumor.In another 25 patients, the patterns of the signal intensity changes were examined in relation to the cardiac cycle by MR images triggered by electrocardiography (EKG) waves. These studies showed that the peak velocity of caudal CSF flow was observed within 200 msec after the R-wave of EKG.In the oter 9 patients, ICP measurement were added to EKG-triggered NR imaging the timing of the maximum velocity of pulsatile CSF flow coincided with the timing of the highest peak of ICP waves in the patients with normal ICP. While in the patientswith high ICP, These timings did not coincide each other.Itmay be possible to estimate ICP noninvasively by observation of the patterns of CSF signal intensity change on EKG-triggered MR studies.