MRI STIR序列对非神经根源性腰痛患者的诊断价值

【摘要】 目的：观察MRI检查中短T1反转回复（short T1 inversion-recovery,STIR）成像技术对于非神经根源性腰痛患者腰椎退变性病变的显示能力,评价其临床应用价值。方法：2010年9月～2011年6月对在我院就诊的有腰痛症状但无神经根放射痛症状的患者进行腰椎MRI扫描,共纳入130例患者,其中男89例,女41例,年龄17~81岁,平均48.3±16.0岁。病史均超过1年。MRI扫描序列包括：矢状面TSE-T1WI、TSE-T2WI、STIR序列,横断面TSE-T2WI序列。对STIR图像及TSE-T2WI图像上腰椎退变性病变进行观察,观察内容包括：L1～S1椎间盘退变情况、椎间盘突出/膨出的节段及程度、腰椎小关节骨质增生情况、棘间韧带水肿情况和腰背部皮下软组织水肿情况。分别对STIR序列与TSE-T2WI序列发现腰椎间盘退变、椎间盘突出/膨出、椎小关节病变、腰部软组织病变的能力进行比较。结果：130例非神经根源性腰痛患者中,STIR序列对于腰椎间盘退变、棘间韧带水肿及腰背部皮下软组织水肿的检出数分别为482个、118节和25例,TSE-T2WI序列检出311个、42节和8例,两序列检出率有显著性差异（P<0.05）;STIR与TSE-T2WI序列对于腰椎间盘突出/膨出和椎小关节骨质增生的检出数均为182个和71个,无差异。两序列均发现5例腰椎滑脱,19例腰椎管狭窄。结论：MRI STIR序列对非神经根源性腰痛患者腰椎间盘退变、棘间韧带水肿及腰背部皮下软组织水肿显示能力优于MRI T2WI。     

增强FLAIR T2WI序列在脑膜瘤中的表现及价值

目的:通过与增强T1WI的比较研究探讨增强FLAIR T2WI在脑膜瘤中的表现及价值。方法:回顾性分析38例脑膜瘤患者共42个脑膜瘤的常规SE T1WI和FLAIR T2WI增强序列影像表现,对比小脑膜瘤组(直径<2cm)及大脑膜瘤组(直径>2cm)在常规SE T1WI和FLAIR T2WI增强中瘤体的强化程度,并分析两者间差别。结果:两组强化程度显著性存在统计学差异,大脑膜瘤组在增强T1WI序列较FLAIR T2WI增强序列强化显著多见;而小脑膜瘤组在FLAIR T2WI增强序列较增强T1WI序列强化显著多见。结论:增强FLAIR较增强T1WI更有助于小脑膜瘤的显示和判断,但在大脑膜瘤显示肿瘤本身上不及增强T1WI。     

肝脏液体衰减反转恢复序列最佳参数的选择及临床应用

目的:探讨液体衰减反转恢复(FLAIR)序列肝脏扫描的最佳参数及临床应用价值。方法:体外实验组将6组不同血红蛋白浓度液体和5组不同浓度的肝囊肿穿刺液埋于载体中,经0.5 T超导MR机行T2WI及FLAIR序列(TR6000 ms,TE 100 ms,TI 1500/1700/1900 ms)扫描,检测并分析相同病灶在T2WI及不同TI值的FLAIR成像的信号强度。结果:体外实验结果显示FLAIR成像随液体蛋白浓度(≥1.64 g/dl)升高和TI值延长其信号呈逐渐升高趋势,优选参数FLAIR成像(TI 1700 ms)可鉴别肝囊肿与肝血管瘤(P<0.05)。结论:FLAIR成像可初步判定液体蛋白含量,优选参数的FLAIR成像结合常规SE序列可提高肝脏病变的鉴别诊断。     

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。     

T2 FLAIR增强扫描在颅内病变中价值的初步研究

目的探讨增强T2FLAIR在颅内病变诊断中的价值。方法58例资料完整并在增强T1WI或增强FLAIR上有强化的患者,确定增强T1WI和增强FLAIR上病变有无强化、强化的显著性、肿瘤性病变强化区的边界。结果3例脑梗塞在增强T1WI上未见强化,3例脑肿瘤在增强FLAIR上未见强化,1例脑膜瘤在增强FLAIR上呈负性强化;余51例中11例在增强FLAIR上强化更显著,16例在2个序列上强化相似,24例在T1WI上强化更显著。4例结核的脑膜病变范围和1例静脉窦血栓者回流受阻的皮层静脉在增强FLAIR上显示更加明确。结论增强T2FLAIR在颅内病变的诊断中有一定的价值,当增强T1WI显示不满意、怀疑脑膜或皮层血管病变时,应行增强T2FLAIR。     

MRI characteristics of MOG-Ab associated disease in adults: An update

Our knowledge of the radiological spectrum of myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is growing rapidly. An update on the radiological features of the disease, and its evolution is thus necessary. Magnetic resonance imaging (MRI) has an increasingly important role in the differential diagnosis of MOGAD particularly from aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD), and multiple sclerosis (MS). Differentiating these conditions is of prime importance because the management is different between the three inflammatory diseases, and thus could prevent further attack-related disability. Therefore, identifying the MRI features suggestive of MOGAD has diagnostic and prognostic implications. We herein review optic nerve, spinal cord and the brain MRI findings from MOGAD adult patients, and compare them to AQP4-NMOSD and MS.     

Whole-body MRI in children: Would a 3D STIR sequence alone be sufficient for investigating common paediatric conditions? A comparative study

ObjectivesTo test the performance of a single 3D IR T2-Weighted sequence compared to a Whole-body MRI protocol including DWI, T1-Weighted and STIR 3D IR (3S) in a pediatric population.MethodsTwo radiologists (15 and 30 years of experience),reviewed WBMRIs: first the STIR alone and 2 weeks later the 3S protocol. The indications were variable. Only positive findings were explicitly reported. A third reader compared the results to gold standard (GS) exams specific for the pathology. Agreement between the two readers, sensitivity and positive predictive value of STIR were calculated.Resultsfifty-four WBMRIs were included (16 suspected child abuse, 8 chronic recurrent multifocal osteomyelitis (CRMO), 11 lymphomas, 4 osteosarcomas, 9 neuroblastomas, 6 histiocytosis). The mean age was 6 years 10 months, range: 1 month to 15 years.Agreement between readers was of 0.87 [0.82–0.91] for 3D STIR, and 0.89 [0.83–0.93] for the 3S protocol. For reader 1 sensitivity of 3D STIR was 81.6% and of 3S 81.0%. For reader 2 it was 74.1% for 3D STIR and 74.7% for 3S. For both readers and for both protocols, the positive predictive value (PPV) depended on the type of disease (for example 100% histocytosis and osteosarcomas, >90% for child abuse, >85% CRMO but <70% for lymphoma and neuroblastoma).ConclusionsSensitivities were not different between the 2 protocols, for each reader and were different between the 2 readers for each protocol.     

3D-FLAIR magnetic resonance imaging in the evaluation of mumps deafness

A 6-year-old boy suffered acute profound right side deafness after his classmates had mumps. Although his salivary glands were not swollen, he had high levels of anti-mumps IgM and IgG antibodies. The three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) procedure applied to magnetic resonance imaging (MRI) showed high signals in the right cochlea and vestibule. This indicated hemorrhage or a high concentration of protein in the right inner ear. This is the first case demonstrating a high 3D-FLAIR MRI signal of the inner ear in a patient with mumps deafness. Our findings suggest that 3D-FLAIR MRI may help to identify and define labyrinthitis in mumps deafness.     

Phase-amplitude coupling of ripple activities during seizure evolution with theta phase

ObjectiveHigh-frequency activities (HFAs) and phase-amplitude coupling (PAC) are key neurophysiological biomarkers for studying human epilepsy. We aimed to clarify and visualize how HFAs are modulated by the phase of low-frequency bands during seizures.MethodsWe used intracranial electrodes to record seizures of focal epilepsy (12 focal-to-bilateral tonic-clonic seizures and three focal-aware seizures in seven patients). The synchronization index, representing PAC, was used to analyze the coupling between the amplitude of ripples (80–250 Hz) and the phase of lower frequencies. We created a video in which the intracranial electrode contacts were scaled linearly to the power changes of ripple.ResultsThe main low frequency band modulating ictal-ripple activities was the θ band (4–8 Hz), and after completion of ictal-ripple burst, δ (1–4 Hz)-ripple PAC occurred. The ripple power increased simultaneously with rhythmic fluctuations from the seizure onset zone, and spread to other regions.ConclusionsRipple activities during seizure evolution were modulated by the θ phase. The PAC phenomenon was visualized as rhythmic fluctuations.SignificanceRipple power associated with seizure evolution increased and spread with fluctuations. The θ oscillations related to the fluctuations might represent the common neurophysiological processing involved in seizure generation.     

FLAIR-DWI序列上ROI对脑组织ADC值测量的影响

目的:探讨液体衰减反转恢复预脉冲弥散加权成像(FLAIR-DWI)上感兴趣区(ROI)对脑组织ADC值测量的影响及ROI法不同操作者间对脑组织ADC值测量的一致性.材料和方法:15名健康志愿者在3.0T MR上行颅脑轴位FLAIR-DWI(b=0、1000s/mm2,TI=2250ms),先由一名操作者在ADC图上用3个大小分别为1mm2、30±3mm2和60±3mm2的ROI测量半卵圆区、扣带回、丘脑、胼胝体、脑桥及小脑半球的ADC值;另一名操作者以30±3mm2大小的ROI再次测量半卵圆区、扣带回、丘脑、胼胝体、脑桥及小脑半球的ADC值.结果:在FLAIR-DWI不同部位脑组织的ADC平均值为(6.242～7.807)×10-4mm2/s.改变ROI大小后脑组织内不同部位所测量得到的ADC值无统计学显著性差异;两名操作者以30±3mm2大小的ROI进行ADC测量的结果也没有显著性差异,两者测量结果一致性很高.结论:FLAIR-DWI上一定范围内改变ROI大小对ADC值定量的影响并不显著,且不同操作者对ADC值的测量具有良好的可重复性.