Herlihy A H, Oatridge A, Curati W L, Puri B K, Bydder G M, Hajnal J V
Robert Steiner Magnetic Resonance Unit, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Campus, London, UK.
Magn Reson Med. 2001 Aug;46(2):354-64. doi: 10.1002/mrm.1198.
High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered by Inversion-time for each Slice Position" (KRISP) to achieve constant contrast in a multislice acquisition. Theory shows that with this method the CSF point spread function (PSF) has a minimum at the center and attenuated side lobes, providing CSF suppression, but residual edge signals remain. The PSF for brain is only mildly attenuated and signals for extended regions are not attenuated. KRISP FLAIR sequences were assessed in 15 patients (10 brain and five spinal cord cases). The images showed reduced CSF and blood flow artifacts and higher conspicuity of the cortex, meninges, ventricular system, brainstem, and cerebellum when compared with conventional FLAIR sequences.
脑脊液（CSF）流动产生的高信号伪影会对脑和脊髓的液体衰减反转恢复（FLAIR）成像产生不利影响。本研究探索使用非层面选择反转脉冲消除脑脊液流动伪影，并结合一种称为“每个层面位置按反转时间重排K空间”（KRISP）的技术，以在多层采集中实现恒定对比度。理论表明，使用这种方法，脑脊液点扩散函数（PSF）在中心处有最小值且旁瓣衰减，从而实现脑脊液抑制，但仍残留边缘信号。脑的PSF仅轻度衰减，扩展区域的信号未衰减。对15例患者（10例脑部和5例脊髓病例）进行了KRISP FLAIR序列评估。与传统FLAIR序列相比，图像显示脑脊液和血流伪影减少，皮质、脑膜、脑室系统、脑干和小脑的清晰度更高。
