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

已有研究表明，脑脊液（cSF）在颅腔内流动，在磁共振（MR）图像上失去信号。这被称为“信号空洞现象（SVP）”。我们注意到SVP与颅内压（ICP）水平之间的一些关系。在289例神经外科患者中，MR研究集中于SVP的存在。在颅内压（ICP）正常的C - M通讯性脑积水患者的MR图像中，SVP的出现频率较高，而在颅内压高的患者，如幕上肿瘤患者中，SVP的出现频率较低。在另外25名患者中，通过心电图（EKG）波触发的MR图像检查信号强度变化模式与心脏周期的关系。这些研究表明，尾侧脑脊液血流速度峰值出现在心电图r波后200 msec内。另外9例患者在心电图触发的NR成像中增加了颅内压测量，脑脊液脉动最大流速的时间与正常颅内压患者的颅内压峰值时间一致。而在高颅内压患者中，这些时间并不重合。通过观察脑电图触发的MR研究中脑脊液信号强度变化的模式，可以无创地估计颅内压。

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.