3 T MRIにおけるTime-spatial Labeling Inversion Pulse (Time-SLIP)法を用いた脳脊髄液動態撮像の条件検討: 1.5 T MRIと比較した3 T MRIの有用性

摘要

Cerebrospinal fluid (CSF) imaging by time-spatial labeling inversion pulse (Time-SLIP) technique is labeled by CSF with a selective inversion recovery (IR) pulse as internal tracer, thus making it possible to visualize CSF dynamics non-invasively. The purpose of this study was to clarify labeled CSF signals during various black blood time to inversion (BBTI) values at 3 tesla (T) and 1.5 T magnetic resonance imaging (MRI) and to determine appropriate CSF imaging parameters at 3 T MRI in 10 healthy volunteers. To calculate optimal BBTI values, ROIs were set in untagged cerebral parenchyma and CSF on the image of the CSF flow from the aqueduct to the fourth ventricle in1.5 T and 3 T MRI. Visual evaluation of CSF flow also was assessed with changes of matrix and echo time (TE) at 3 T MRI. The mean BBTI value at null point of untagged CSF in 3 T MRI was longer than that of 1.5 T. The MR conditions of the highest visual evaluation were FOV,14 cm × 14 cm; Matrix, 192 × 192; and TE, 117 ms. in more detail by setting the optimal conditions because 3 T MRI has the advantage of high contrast and high signal-to-noise ratio.%Cerebrospinalfluid(CSF)の動態を調べるための検査法として，外因性トレーサである放射性同位元素を腰椎穿刺によって脊髄腔内に投与して観察する脳槽シンチグラフィやヨード造影剤を使用したcomputed tomography (CT) cisternography (脳槽造影)が従来から用いられている.更に，magnetic resonance imaging (MRI)の登場によってphase contrast (PC)法を用いて，流体の位相差を利用したCSFの動態の画像化もしくは定量化が可能となり,非侵襲的な検査法として研究が行われるようになった.しかし，これまでのところ，いずれの方法も診断的有用性のある手法としては確立されてはいない.