Herlihy A H, Hajnal J V, Curati W L, Virji N, Oatridge A, Puri B K, Bydder G M
Robert Steiner Magnetic Resonance Unit, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, Du Cane Rd, London W12 0HS, UK.
AJNR Am J Neuroradiol. 2001 May;22(5):896-904.
Our purpose was to test a new variant of the fluid-attenuated inversion-recovery (FLAIR) sequence that was designed to reduce CSF and blood flow artifacts by use of a non-slice-selective inversion pulse and k-space reordered by inversion time at each slice position (KRISP).
With the KRISP FLAIR sequence, the slice order was cycled so that each inversion time (TI) was associated with a region of k-space rather than a particular slice, and the effective inversion time (TI(eff)) was chosen to null the signal from CSF. Scans were obtained with both conventional and KRISP FLAIR sequences. Studies were performed in 20 adult patients with a variety of brain diseases. Images were evaluated for artifacts from patient motion, CSF, and blood flow, and scored on a four-point scale. The conspicuity of the cortex, meninges, ventricular system, brain stem, and cerebellum was evaluated, as was lesion number and conspicuity.
The KRISP FLAIR sequence showed more patient motion artifacts but had a pronounced advantage over the conventional sequence in control of CSF artifacts around the foramen of Munro, in the third ventricle, aqueduct, and fourth ventricle, as well as in the basal cisterns and around the brain stem and cerebellum. Blood flow artifacts from the internal carotid, basilar, and vertebral arteries were also much better controlled. Spurious high signal in the sylvian branches of the middle cerebral artery was eliminated. The meninges, cortex, ventricular system, brain stem, and cerebellum were better seen due to improved artifact suppression and an edge enhancement effect.
The KRISP FLAIR sequence can suppress CSF and blood flow artifacts and improve the conspicuity of the meninges, cortex, brain stem, and cerebellum. Its major disadvantage is its duration, which may be reducible with a fast spin-echo version.
我们的目的是测试一种新的液体衰减反转恢复（FLAIR）序列变体，该变体通过使用非层面选择反转脉冲和在每个层面位置按反转时间重新排序的 k 空间（KRISP）来减少脑脊液和血流伪影。
使用 KRISP FLAIR 序列时，层面顺序循环，以便每个反转时间（TI）与 k 空间的一个区域相关联，而不是与特定层面相关联，并且选择有效反转时间（TI(eff)）以消除脑脊液信号。使用传统和 KRISP FLAIR 序列进行扫描。对 20 名患有各种脑部疾病的成年患者进行了研究。对图像评估患者运动、脑脊液和血流产生的伪影，并按四点量表评分。评估了皮质、脑膜、脑室系统、脑干和小脑的清晰度，以及病变数量和清晰度。
KRISP FLAIR 序列显示出更多的患者运动伪影，但在控制蒙罗氏孔周围、第三脑室、导水管和第四脑室以及基底池和脑干及小脑周围的脑脊液伪影方面比传统序列具有明显优势。来自颈内动脉、基底动脉和椎动脉的血流伪影也得到了更好的控制。大脑中动脉脑沟分支中的假性高信号被消除。由于伪影抑制改善和边缘增强效应，脑膜、皮质、脑室系统、脑干和小脑看得更清楚。
KRISP FLAIR 序列可以抑制脑脊液和血流伪影，并提高脑膜、皮质、脑干和小脑的清晰度。其主要缺点是扫描持续时间，快速自旋回波版本可能会缩短该时间。
