MRI T2加权像在脑脊液鼻漏中的应用

目的 研究MRI T2加权像在脑脊液鼻漏漏口定位中的应用价值.方法 10例脑脊液鼻漏患者经MRI T2加权像检查,通过观察动态脑脊液经漏口流入鼻旁窦腔形成的长T2高信号漏迹进行术前漏口定位,其中通过改变体位致动态脑脊液鼻漏者6例;通过压迫双侧颈静脉以增加颅内压形成动态腩脊液鼻漏者4例.将MRI检查结果 与手术中探查所见进行比较.结果 10例患者术中探查的漏口位置与术前MRI定位完全相符.MRI T2加权像表现为漏口呈锥形长T2高信号疝入漏道,漏迹呈连续或不连续的线样长T2高信号及患侧鼻旁窦腔内积聚脑脊液样长T2高信号.其中漏入筛窦者7例;漏入蝶窦者2例;另1例在自由水抑制成像(fluid attenuated inversion recovery,FLAIR)及脂肪抑制FSET2W1上见左侧乳突气房及鼓室有不规则线样高信号,判断漏口位于乳突气房及鼓室盖,脑脊液经漏口至内耳通过耳咽鼓管漏出鼻腔.结论 MRI T2加权像成像技术对术前脑脊液漏的漏口定位具有定位准确、无侵袭性、无放射性以及解剖结构清楚等优点,可作为无创检查方法 之一.不同患者采取个体化MRI检查方法 (如改变体位或压迫双侧颈静脉等)是准确进行漏口定位的关键.

The evaluation of MRI T2-weighted images in diagnosis of CSF fistula in patients with leakage of CSF

Objective To study the clinical usefulness and sensitivity of MRI T2-weighted images as non-invasive study in the diagnosis of CSF fistula in patients with leakage of CSF.Methods Ten patients with clinical diagnosis as CSF rhinorrhea were prospectively evaluated by MRI.The MRI examinations included fast spin-echo T2- weighted images in the 3 orthogonal planes.MRI findings were correlated with surgical results in 10 patients.Results The site of the CSF rhinorrhea was identified in all 10 patients(100%)and was verified at surgery in all patients.CSF fistula Was visualised as a fistular tract connecting subarachnoid space to paranasal sinus,or presence of brain herniation on T2-weighted images.The location of connecting fislular tract were ethmoid sinus,sphenoidal sinus and roof of tympanum of 70%,20%,10% respectively.Conclusions In the presence of CSF rhinorrhea,MRI T2-weighted image is a sensitive and accurate technique in the assessment of patients with CSF fistular even in patients who are not actively leaking at the time of evaluation.It is non-invasive,no radiation risk and offers excellent anatomical detail.Individual MRI examination such as altering body position or oppressing jugular vein is the key to visualization of CSF fistular.