正常及病理状态下FLAIR图像上脑室内脑脊液搏动伪影的表现

目的探讨正常人及病理状态下轴位液体衰减反转恢复（FLAIR）图像上脑室内脑脊液伪影（VCSFA）的表现,及其在对比剂增强前后的变化。方法262例患者分为3组,A组颅脑无异常者126例,B组无占位效应的脑内病变101例,C组有占位效应的颅内病变35例,均行头颅FLAIR检查,其中52例行静脉注入对比剂后的增强FLAIR检查。记录各脑室系统的VCSFA并进行比较。结果VCSFA的发生率为55.0%,以四脑室最为常见。侧脑室者多位于孟氏孔附近呈椭圆形,三脑室者多为片状,四脑室者常在上部呈圆形,导水管者则位于其末端呈圆形。A组和B组的VCSFA发生率分别为57.9%、54.5%,均高于C组的45.7%。VCSFA的发生与三脑室直径无关。2.8%的VCSFA在相位编码方向上可见搏动伪影,15.4%的患者增强前后VCSFA发生变化。结论VCSFA是FLAIR图像上的常见现象,有一定的特征性表现。占位性病变和对比剂对VCSFA有一定的影响。

Intraventricular CSF pulsation artifact on FLAIR images: analysis of normal and pathologic state studies

Objective To study ventricular CSF pulsation artifact (VCSFA) on axial FLAIR images in normal subjects and in patients with pathologic state, and its changes before and after administration of gadopentetate dimeglumine. Methods Two hundred and sixteen-two patients were divided into three groups: 126 normal subjects as group A, 101 patients with various pathologic state without space-occupying effect as group B, and 35 patients with space-occupying effect as group C. All subjects underwent axial FLAIR imaging, among which 52 subjects having administration of Gd-DTPA. The VCSFA and third ventricular width were recorded. Results The rate of VCSFA was 55.0%, and the fourth ventricle was the most common site. Lateral ventricular VCSFA was most commonly adjacent to the foramen of Monro and was in ellipse shape, the third ventricular VCSFA was in plate shape, the fourth ventricular VCSFA almost located at its top with round shape, and aqueduct VCSFA was in its termination with round shape. The rates of VCSFA were 57.9% and 54.5% in group A and B, but the rate was lower in group C (45.7%). There was no relationship between third ventricular size and VCSFA. Ghost pulsation artifacts in the phase-encoding axis were seen in 2.8% VCSFA. VCSFA change was seen in 15.4% of subjects after administration of Gd-DTPA. Conclusion VCSFA was commonly found on axial FLAIR images, which had some characteristic appearance. Space-occupying lesion and contrast medium had some effect on VCSFA.