Bozzao Alessandro, Floris Roberto, Fasoli Fabrizio, Fantozzi Luigi Maria, Colonnese Claudio, Simonetti Giovanni
Department of Neuroradiology, University of Rome "La Sapienza", Ospedale Sant'Andrea, Via di Grottarossa 1035, 00189 Rome, Italy.
Eur Radiol. 2003 Mar;13(3):592-7. doi: 10.1007/s00330-002-1546-4. Epub 2002 Jul 13.
Fluid-attenuated inversion recovery (FLAIR) sequence is currently used in clinical practice. Some reports emphasize the possibility that, in pathologic conditions, intravenous injection of gadolinium chelates may lead to an increased signal inside the cerebrospinal fluid (CSF). The aim of this study was to evaluate the presence of CSF signal changes in pathologic conditions causing blood-brain barrier disruption or neovascularization when imaging is performed after intravenous injection of gadolinium. We obtained FLAIR sequences after gadolinium injection from 33 patients affected by different intracranial pathologies and 10 control subjects. Patients were affected by ischemic stroke in the subacute phase, from 2 to 7 days from onset of symptoms (12 patients), meningiomas (8 patients), high-grade gliomas (5 patients), previous surgical procedures for intra-axial neoplasms (5 patients), and multiple sclerosis with active plaques (3 patients). Magnetic resonance imaging was performed in patients and controls using a 1.5-T magnet, using T2- and T1-weighted FLAIR sequences. The FLAIR sequence was acquired before and 1-3 h after injection of a standard dose of gadolinium. In those patients affected by ischemic lesions, FLAIR sequences were repeated the next days and 3-4 days later. The CSF signal was visually evaluated by two readers and scored from 0 to 3 depending by the degree of enhancement. The location of CSF signal changes (close to the lesion, hemispheric, or diffuse) was also considered. The CSF signal was markedly increased after 3 h from intravenous injection of gadolinium in all the patients with stroke, in those with previous surgery, and in those with high-grade gliomas whose neoplasm's surface was in contact with the subarachnoid spaces (SAS) or ventricles; a strong enhancement was also evident inside the necrotic component of the tumor. The CSF changes were more evident close to the pathology and/or in the hemisphere involved by the pathology. Moderate CSF enhancement was observed in the SAS close to meningiomas. No signal changes were evident in all the others. In those patients with stroke imaged in the following days, CSF signal showed to be diffuse to both hemispheres the next day and returned to normal values within 2 days. In patients affected by pathologies with blood-brain barrier breakdown or neovascularization close the SAS or the ventricles, CSF changes, related to gadolinium leakage, are likely when FLAIR sequences are acquired 2-24 h after i.v. injection of the contrast. This pattern should be known in order to differentiate it from that of subarachnoid hemorrhage.
液体衰减反转恢复（FLAIR）序列目前应用于临床实践。一些报告强调，在病理情况下，静脉注射钆螯合物可能导致脑脊液（CSF）内信号增强。本研究的目的是评估在静脉注射钆后进行成像时，导致血脑屏障破坏或新生血管形成的病理情况下脑脊液信号变化的存在情况。我们从33例患有不同颅内病变的患者和10例对照受试者中获取了注射钆后的FLAIR序列。患者患有亚急性期缺血性中风，症状发作后2至7天（12例）、脑膜瘤（8例）、高级别胶质瘤（5例）、既往轴内肿瘤手术患者（5例）以及有活动性斑块的多发性硬化症患者（3例）。患者和对照受试者使用1.5-T磁体进行磁共振成像，采用T2加权和T1加权FLAIR序列。在注射标准剂量的钆之前和之后1 - 3小时采集FLAIR序列。对于那些患有缺血性病变的患者，在接下来的几天以及3 - 4天后重复采集FLAIR序列。由两位阅片者对脑脊液信号进行视觉评估，并根据增强程度从0到3进行评分。还考虑了脑脊液信号变化的位置（靠近病变、半球或弥漫性）。在所有中风患者、既往接受过手术的患者以及高级别胶质瘤肿瘤表面与蛛网膜下腔（SAS）或脑室接触的患者中，静脉注射钆3小时后脑脊液信号明显增强；肿瘤坏死成分内也有明显的强化。脑脊液变化在靠近病变处和/或病变累及的半球更为明显。在靠近脑膜瘤的蛛网膜下腔观察到中度脑脊液强化。其他所有患者均未观察到信号变化。在接下来几天进行成像的中风患者中，脑脊液信号在第二天显示为双侧半球弥漫性，2天内恢复正常。在患有血脑屏障破坏或靠近蛛网膜下腔或脑室有新生血管形成的病变的患者中，静脉注射造影剂后2 - 24小时采集FLAIR序列时，可能会出现与钆渗漏相关的脑脊液变化。应该了解这种模式，以便将其与蛛网膜下腔出血的模式区分开来。
