FLAIR增强扫描在脑转移瘤诊断中的价值

目的通过与平扫液体衰减反转恢复(FLAIR)及增强T1WI的比较研究,探讨增强FLAIR序列在脑转移瘤诊断中的价值。资料与方法20例脑转移瘤患者行增强前后T1WI和FLAIR成像,计数两种序列上转移瘤的数目,测量肿瘤强化程度、强化百分比和肿瘤体积,计算肿瘤与白质、肿瘤与脑脊液的对比率(CR)和对比噪声比(CNR)。结果20例中1例仅增强T1WI发现3个点状强化灶,余19例共327个转移灶中平扫FLAIR序列发现100个,增强T1WI发现292个,两者共发现298个;增强FLAIR序列发现181个。与增强T1WI相比,仅增强FLAIR序列显示的35个转移灶中,26个位于皮层或皮层下;2个小脑半球灶直径达14mm,余33个直径均<5mm。受血管结构的影响,增强T1WI上7个病灶假阳性,9个为假阴性,而在增强FLAIR序列上均明确诊断。在T1WI上肿瘤的强化程度和强化百分比高于FLAIR序列,而肿瘤与白质、肿瘤与脑脊液的CR和CNR则以FLAIR序列为高,增强T1WI和增强FLAIR序列上的转移瘤体积平均为(4.2±6.2)cm3和(4.0±6.5)cm3,两者差异无统计学意义。结论增强FLAIR序列在脑转移瘤的诊断中有一定的价值,尤其是对位于皮层表面的病灶,其与增强T1WI具有很好的互补性。     

增强FLAIR T2WI诊断脑膜转移瘤的价值

目的:探讨脑膜转移瘤的MRI表现及增强后FLAIR序列T2WI的诊断价值。方法:回顾性分析20例脑膜转移瘤患者的病例资料,其中硬脑膜转移瘤5例,软脑膜转移瘤15例。所有病例行常规MRI平扫及SE T1WI和FLAIR序列T2WI增强扫描并进行对比分析。结果:MRI平扫检出6例,病灶边界均显示不清;MRI增强扫描检出所有病例,SE-T1WI上病变主要表现为脑膜的线状和/或结节状强化,FLAIR T2WI对软脑膜转移瘤病灶范围的显示更清楚,可鉴别强化的血管与病变。结论:MRI增强扫描是诊断脑膜转移瘤的重要检查方法,增强后FLAIR序列T2WI与SE T1WI同时使用,可提高对软脑膜转移瘤的检出率及诊断准确性。     

MR增强后液体衰减反转恢复序列对脑转移瘤的诊断价值

目的 分析MR增强后液体衰减反转恢复(fluid attenuated inversion recovery,FLAIR)序列对脑转移瘤的诊断价值. 资料与方法 确诊恶性肿瘤可疑有脑转移患者159例.MR检查除常规平扫和增强外,在增强后加扫FLAIR序列,图像由3名有经验的放射科医师评估. 结果 58例有脑内转移,6例增强后FLAIR脑实质病灶数目显示较增强T1WI多,11例病灶强化较T1WI明显;在11例柔脑膜转移者中,7例病灶强化程度优于增强后T1WI. 结论 增强后FLAIR是增强后T1WI的有效补充,对脑内小病灶和脑膜病灶更敏感.     

增强T2-FLAIR序列在颅内转移瘤诊断价值

目的：对比增强T2-FLAIR序列及增强T1WI序列,探讨增强T2-FLAIR序列在脑转移瘤中的应用价值。方法：收集2021年1月—2022年12月本院收治的经病理确诊为原发性肿瘤、同时确诊或怀疑有脑转移的患者58例,患者在进行传统的MRI平扫及增强检查的基础上,加做增强T2-FLAIR序列。观察2种增强序列图像上转移瘤的数量、大小、部位及转移瘤的强化显示程度,并进行统计学分析。结果：本组58例患者,增强T2-FLAIR序列显示的部分脑实质结节状转移及软脑膜转移的强化程度,显著高于增强T1WI序列,差异具有统计学意义（P<0.05）,脑实质结节转移的直径增强T2-FLAIR序列较增强T1WI序列大,差异具有统计学意义（P<0.05）。结论：增强T2-FLAIR序列对于软脑膜的转移及皮质区的小结节状转移灶有很高的检出率,对常规的MRI增强起到很好的补充作用,两者联合使用可以显著提高脑转移瘤的诊断准确性。     

增强液体衰减反转恢复序列在脑膜瘤诊断中的应用价值

目的 探讨增强液体衰减反转恢复(FLAIR)序列在诊断脑膜瘤中的价值. 资料与方法 38例脑膜瘤患者行增强T1WI和FLAIR成像,比较两种序列增强图像上脑膜瘤的强化方式、"脑膜尾征"的显示、肿瘤强化程度、肿瘤与白质及肿瘤与灰质的对比率(CR)和对比噪声比(CNR). 结果 38例中25例(65.8%)在增强FLAIR上呈环状强化,而增强T1WI上仅7例(18.4%)呈环状强化."脑膜尾征"在增强FLAIR和增强T1WI上的显示率分别为36.8%和47.4%.肿瘤在增强FLAIR和增强T1WI上强化程度分别为57.0和301.3,两者间差异有统计学意义(P＜0.001).增强FLAIR和增强T1WI上肿瘤与灰质CR分别为0.9和1.5,两种序列上肿瘤与白质的CNR分别为50.6和72.6,肿瘤与灰质CNR则为44.3和80.1,两种序列间差异均有统计学意义(P＜0.001).肿瘤与白质CR在两种序列间无差异. 结论 增强FLAIR有助于脑膜瘤包膜的显示和判断,但在显示肿瘤本身及"脑膜尾征"上不及增强T1WI.     

颅内柔脑膜转移瘤：低场MRI FLAIR序列与T1WI增强扫描对比分析

目的:评估低场MR液体衰减反转恢复(FLAIR)序列诊断颅内柔脑膜转移瘤的价值.材料和方法:回顾性分析30例颅内柔脑膜转移瘤的FLAIR序列平扫与T1WI常规剂量增强扫描的表现.结果:T1WI增强扫描检出柔脑膜转移瘤128个,而FLAIR检出117个,T1WI增强扫描检出病灶较FLAIR序列敏感(P<0.05);T1WI增强扫描明确所有病灶边界,而FLAIR序列对所有病灶的边界显示不清.结论:对于颅内柔脑膜转移瘤的低场MR诊断,T1WI增强扫描优于FLAIR序列.     

CUBE T_2 FLAIR序列在脑内微小转移瘤诊断中的应用

目的 :探讨CUBE T2FLAIR序列对脑内微小转移瘤的临床应用价值。方法:对35例脑转移瘤患者行常规扫描后再行3D T1WI序列和CUBE T2FLAIR序列增强扫描,统计并比较2种序列显示转移瘤的数目、大小、位置等。结果:35例共129个病灶,CUBE T2FLAIR显示124个病灶,显示率98.4%;3D T1WI序列显示112个病灶,显示率86.8%,两者比较差异有统计学意义(P=0.014)。结论:在显示脑内微小转移瘤方面,CUBE T2FLAIR序列比3D T1WI序列更敏感。     

增强FLAIR和磁化传递对比对脑转移瘤的诊断价值

目的:对照分析增强液体衰减反转恢复(FLAIR)和磁化传递对比(MTC)两种序列对脑转移瘤的诊断价值.方法:27例患有原发性肺癌且临床怀疑有脑转移的患者,比较增强后T1WI、MTC以及FLAIR显示脑转移病变的数目、位置及强化程度,并分析三者之间偏差的原因.结果:27例患者中,共计发现168个转移灶.增强后MTC显示166个病灶(98.8%),增强后FLAIR显示162个病灶(96.4%),增强T1 WI显示病灶最少,为148个(88.1%).大部分病灶强化程度与扫描延迟时间有关.增强后T1WI及MTC因与脑表面小血管混淆而致误判2枚病灶,在对比增强FLAIR均可明确诊断.结论:增强后FLAIR在脑转移瘤诊断中有一定价值,与MTC联合应用能提高脑转移瘤的诊断准确率.     

自旋回波与翻转恢复T1WI在原发性脑肿瘤诊断中的比较

目的:通过SET1WI与T1FLAIR的比较研究,探讨原发性脑肿瘤MRI的最佳T1WI序列。方法:77例原发性脑肿瘤患者行增强前后SET1WI和T1FLAIR,比较两序列增强图像上肿瘤的边界和肿瘤体积,计算肿瘤与白质、灰质及脑脊液的对比率(CR)和对比噪声比(CNR)。计算并比较两序列上灰质与白质的CR和CNR。结果:增强前T1FLAIR具有更高的CR和CNR,增强后肿瘤与白质、肿瘤与灰质的CR在SET1WI序列上更高,而增强后的3种CNR和肿瘤与脑脊液的CR则在T1FLAIR上更高。在肿瘤边界的显示中,增强前T1FLAIR在46例中更优,31例两序列相似;增强后SET1WI在16例中优于,61例两序列相似。两序列增强图像上测得的肿瘤体积无显著差异。增强前后T1FLAIR上白质与灰质的CR和CNR均高于SET1WI。结论:SE是原发性脑肿瘤增强T1WI的首选序列,T1FLAIR可作为替代序列。     

增强FLAIR序列在颅脑病变中的应用

目的评价增强FLAIR序列在颅脑疾病诊断中的应用.材料与方法50例患者行脑MRI平扫(T1 WI、T2 WI、FLAIR)和Gd-DTPA增强(FLAIR和T1WI)检查,双盲法比较增强前后FLAIR与T1 WI的差异.结果所有病变在FALIR均显示不同程度的异常增强,在脑梗塞疾病中增强FLAIR诊断敏感性大于增强T1 WI.星形细胞瘤、转移瘤和结核瘤,T1 WI增强优于FLAIR.结论增强FLAIR在检查脑表面病变,如皮质或皮质下梗塞,诊断准确性高于增强T1 WI.     

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。     

Contrast-enhanced multi-shot echo-planar FLAIR in the depiction of metastatic tumors of the brain: comparison with contrast-enhanced spin-echo T1-weighted imaging

BACKGROUND: The usefulness of fast fluid-attenuated inversion-recovery (FLAIR) sequences after administration of contrast medium (f-FLAIR (+)) has been shown in depicting brain tumors including metastases and meningeal carcinomatosis. Contrast-enhanced multi-shot echo-planar FLAIR (Ms-EPI-FLAIR (+)), comprising combined sequences of f-FLAIR (+) and Ms-EPI, may provide the advantages of f-FLAIR (+) along with rapid acquisition. PURPOSE: To compare Ms-EPI-FLAIR (+) with post-contrast spin-echo T1-weighted imaging (SE-T1WI (+)) in the depiction of brain metastases. MATERIAL AND METHODS: In 14 patients with metastatic tumors of the brain, spin-echo precontrast T1-weighted imaging (SE-T1WI (-)), fast spin-echo T2-weighted imaging (FSE-T2WI), fast-FLAIR, SE-T1WI (+), and Ms-EPI-FLAIR (+) were acquired. For qualitative evaluation of SE-T1WI (+) and Ms-EPI-FLAIR (+), receiver operating characteristic (ROC) analysis was performed in two different readers. For quantitative analysis, the intensity ratios (intensity of tumor divided by intensity of peritumoral region) in SE-T1WI (+) and Ms-EPI-FLAIR (+) were compared. RESULTS: Although pre-contrast f-FLAIR detected 84 of 106 tumors, Ms-EPI-FLAIR (+) detected 98 of 106 tumors. In the ROC analysis for observers A and B, Az values in SE-T1WI (+) did not differ from values in Ms-EPI-FLAIR (+). Quantitatively, the intensity ratio in Ms-EPI-FLAIR (+) also did not differ from that in SE-T1WI (+). CONCLUSION: Detectability of brain metastases with Ms-EPI-FLAIR (+) is almost similar to that with SE-T1WI (+). Ms-EPI-FLAIR (+) could be an alternative to SE-T1WI (+) in the depiction of brain metastases.     

基于全肿瘤区域MRI纹理分析鉴别肺癌脑转移瘤病理类型的研究

目的:探讨MRI增强T1加权成像(CE-T1WI)、液体衰减反转恢复序列(FLAIR)及表观扩散系数(ADC)纹理特征在肺腺癌及非腺癌脑转移瘤中的鉴别价值.方法:回顾分析经手术病理或影像随诊证实的脑转移瘤病灶127个,其中腺癌68个,非腺癌59个(鳞癌21个,小细胞肺癌38个).利用ITK-SNAP 3.8.0软件分别...     

Detectability of metastatic brain tumors using gadoteridol-enhanced MRI: usefulness of standard-dose T1-weighted spin-echo image with magnetization transfer and enhanced FLAIR

PURPOSE: The aim of this study was to compare the detectability and image contrast of metastatic brain tumors depicted by T1-weighted MR imaging (T1WI) with the magnetization transfer (MT) technique after the administration of a standard dose(MT-SD-T1WI) or T1WI without MT after the administration of a double dose of gadoteridol(DD-T1WI). We also assessed the usefulness of enhanced fluid attenuated inversion recovery (FLAIR) for depicting very small metastatic tumors. METHODS: Forty-six MRI procedures were performed in 31 patients with metastatic brain tumors that had been diagnosed clinically and radiologically. An incremental dose technique was used with intravenous injections of 0.1 and 0.1 mmol/kg of gadoteridol. In 28 MRI procedures, enhanced FLAIR was carried out after an MT-SD-T1WI study. RESULTS: Detectability was significantly greater with both MT-SD-T1WI and DD-T1WI than with SD-T1WI. However, there was no significant difference between MT-SD- and DD-T1WI. Although an MT pulse increased the contrast between the enhanced tumor and white matter, the contrast between edema and white matter was decreased. Both MT-SD- and DD-T1WI showed small but conspicuous enhanced foci, but we could not determine whether these were vessels or small metastases on the brain surface. However, enhanced FLAIR only demonstrated foci that were thought to be small metastases. CONCLUSIONS: MT-SD- and DD-T1WI had equal ability to detect metastatic brain tumors. Enhanced FLAIR was useful for assessing very small metastases on the brain surface.     

MR imaging of leptomeningeal metastases: comparison of three sequences

BACKGROUND AND PURPOSE: Recent work has shown that fluid-attenuated inversion recovery (FLAIR) imaging with contrast enhancement is highly sensitive for detecting subarachnoid space disease. We hypothesized that contrast-enhanced FLAIR imaging has superior sensitivity to contrast-enhanced T1-weighted MR imaging in detecting leptomeningeal metastases. METHODS: Sixty-eight patients referred for suspected leptomeningeal metastases underwent 74 MR imaging studies. The patients had either temporally related cytologic proof of leptomeningeal metastases or negative results of clinical follow-up confirming absence of leptomeningeal metastases. The MR imaging examinations included unenhanced and contrast-enhanced FLAIR images and contrast-enhanced T1-weighted MR images that were independently reviewed by two neuroradiologists blinded to the results of cytology. Each of the three sequences was reviewed individually and separately and was assigned a score of positive or negative for leptomeningeal metastases. Discrepancies were settled by consensus. RESULTS: Of the 17 studies of patients with cytology-proven leptomeningeal metastases, two were positive based on unenhanced FLAIR images, seven were positive based on contrast-enhanced FLAIR images, and 10 were positive based on contrast-enhanced T1-weighted MR images. Of the 57 studies of patients without leptomeningeal metastases, 53 were negative based on unenhanced FLAIR images, 50 were negative based on contrast-enhanced FLAIR images, and 53 were negative based on contrast-enhanced T1-weighted MR images. The sensitivity and specificity of unenhanced FLAIR images for detecting leptomeningeal metastases were 12% (two of 17) and 93% (53 of 57), respectively. The sensitivity and specificity for contrast-enhanced FLAIR images for detecting leptomeningeal metastases were 41% (seven of 17) and 88% (50 of 57), respectively. The sensitivity and specificity of contrast-enhanced T1-weighted MR images for detecting leptomeningeal metastases were 59% (10 of 17) and 93% (53 of 57), respectively. CONCLUSION: Contrast-enhanced fast FLAIR sequences are less sensitive than standard contrast-enhanced T1-weighted MR sequences in detecting intracranial neoplastic leptomeningeal disease.     

Contrast-enhanced FLAIR imaging in combination with pre- and postcontrast magnetization transfer T1-weighted imaging: usefulness in the evaluation of brain metastases

PURPOSE: To assess whether the use of postcontrast fluid-attenuated inversion recovery (FLAIR) imaging in combination with pre- and postcontrast magnetization transfer (MT) T1-weighted imaging (T1WI) can increase diagnostic confidence in the evaluation of brain metastases. MATERIALS AND METHODS: Brain MR images from 41 patients with suspected brain metastases were reviewed. Two radiologists viewed pre- and postcontrast MT-T1W images for the presence of metastatic tumors and rated the possible enhanced lesions using a five-point confidence scale (session 1). The postcontrast FLAIR images were then viewed together with pre- and postcontrast MT-T1W images, and the presence of metastasis was rated again (session 2). RESULTS: A total of 240 possible enhanced lesions were detected in session 1. Judging by follow-up MR examinations, 196 were considered to be nonmetastatic findings and 44 were determined to be metastasis. In session 2 the confidence rating for nonmetastasis increased significantly in the subset of nonmetastatic findings (P < 0.001), and the confidence rating for metastasis increased significantly in the subset of metastases (P < 0.05). CONCLUSION: The addition of postcontrast FLAIR imaging to pre- and postcontrast MT-T1WI improves diagnostic confidence in evaluation of brain metastases.     

MRI各序列诊断创伤性脑损伤的价值比较 MRI各序列诊断创伤性脑损伤的价值比较

目的：比较MRI各序列诊断创伤性脑损伤（traumatic brain injury,TBI）的价值.方法：对260例TBI患者行MRI序列组合扫描,包括FLASH、FLAIR、SE T1WI、TSE T2WI,分析不同类型TBI的影像特点,比较各序列对病灶的显示率.结果：260例中,FLASH显示244例（93.8％）,FLAIR显示249例（95.8％）,T2WI显示200例（76.9％）,T1WI显示199例（76.5％）,FLASH与FLAIR比较、T2WI与T1 WI比较,显示率差异均无统计学意义（P均＞0.05）;FLASH、FLAIR分别与T2WI、T1WI相比,显示率差异均有统计学意义（P均＜0.01）,FLASH、FLAIR对TBI病变的显示优于T2WI、T1WI.结论：MRI各序列显示TBI病灶总体敏感性由高至低依次为FLAIR、FLASH、T2WI、T1WI.FLAIR、FLASH应作为MRI诊断TBI的首选序列.     

Utility of Contrast-Enhanced T2 FLAIR for Imaging Brain Metastases Using a Half-dose High-Relaxivity Contrast Agent

BACKGROUND AND PURPOSE:Efficient detection of metastases is important for patient’ treatment. This prospective study was to explore the clinical value of contrast-enhanced T2 FLAIR in imaging brain metastases using half-dose gadobenate dimeglumine.MATERIALS AND METHODS:In vitro signal intensity of various gadolinium concentrations was explored by spin-echo T1-weighted imaging and T2 FLAIR. Then, 46 patients with lung cancer underwent nonenhanced T2 FLAIR before administration of half-dose gadobenate dimeglumine and 3 consecutive contrast-enhanced T2 FLAIR sequences followed by 1 spin-echo T1WI after administration of half-dose gadobenate dimeglumine. After an additional dose of 0.05 mmol/kg, 3D brain volume imaging was performed. All brain metastases were classified as follows: solid-enhancing, ≥ 5 mm (group A); ring-enhancing, ≥ 5 mm (group B); and lesion diameter of <5 mm (group C). The contrast ratio of the lesions on 3 consecutive phases of contrast-enhanced T2 FLAIR was measured, and the percentage increase of contrast-enhanced T2 FLAIR among the 3 groups was compared.RESULTS:In vitro, the maximal signal intensity was achieved in T2 FLAIR at one-eighth to one-half of the contrast concentration needed for maximal signal intensity in T1WI. In vivo, the mean contrast ratio values of metastases on contrast-enhanced T2 FLAIR for the 3 consecutive phases ranged from 63.64% to 83.05%. The percentage increase (PI) values of contrast-enhanced T2 FLAIR were as follows: PI_A < PI_B (P = .001) and PI_A < PI_C (P < .001). The degree of enhancement of brain metastases on contrast-enhanced T2 FLAIR was lower than on 3D brain volume imaging (P < .001) in group A, and higher than on 3D brain volume imaging (P < .001) in group C.CONCLUSIONS:Small or ring-enhancing metastases can be better visualized on delayed contrast-enhanced T2 FLAIR using a half-dose high-relaxivity contrast agent.

Brain metastases occur in approximately 25% of patients with cancer and account for 40% of adult brain tumors.¹ The incidence of brain metastases in patients with lung cancer is highest (19.9%),² resulting in high morbidity and mortality.³ Small metastases, not combined with vasogenic edema or mass effects, are often missed.¹ Improvement of the early detection of small brain metastases will contribute to developing treatment protocols and will affect the outcomes⁴ because small lesions effectively respond to therapies and can be controlled at a substantially higher rate compared with larger lesions.^5,6 For patients with metastases, contrast-enhanced T1WI (CE-T1WI) should be repeatedly performed to assess the progress of brain metastases^7,8 or the efficacy of treatment.^9,10 The conspicuity and detection rate of brain metastases can be improved with a higher dose of gadolinium-based contrast agents (GBCA).¹¹ However, multiple enhanced examinations or use of higher contrast doses may increase the potential adverse effects, such as nephrogenic systemic fibrosis,^12,13 and may lead to higher gadolinium deposition in the brain¹⁴ or other tissues.^15,16Therefore, reducing the gadolinium-based contrast agent dose may decrease the adverse effects produced by gadolinium accumulation, which is crucial to the patient’s health. T2 FLAIR is an inversion recovery pulse sequence that is sensitive to low concentrations of GBCA in the tissue.¹⁷ It is reported that only one-quarter of the routine dose of GBCA is needed for CE-T2 FLAIR to achieve a signal enhancement comparable with that of CE-T1WI; moreover, CE-T2 FLAIR may offer additional morphologic information compared with CE-T1WI alone.^17,18 Due to the suppression of intravascular and CSF signal,¹⁹ CE-T2 FLAIR imaging has been used in the detection of various intra- and extra-axial brain lesions, eg, the delineation of meningeal lesions including meningoencephalitis and leptomeningeal metastases.^20-22Previous studies mostly focused on the use of CE-T2 FLAIR after use of the normal GBCA dose; no studies were performed to assess the utility of low-dose CE-T2 FLAIR in the detection of brain metastases. Additionally, an increased delay of CE-T2 FLAIR scanning can improve the diagnosis of leptomeningeal infectious or tumoral diseases,²³ which means CE-T2 FLAIR has a relationship with scanning time. The purpose of the present study was to investigate the value of delayed low-dose CE-T2 FLAIR compared with routine-dose CE brain volume imaging (BRAVO; GE Healthcare) for contrast enhancement in brain metastases.     

Role of fluid-attenuated inversion recovery in the diagnosis of meningitis: comparison with contrast-enhanced magnetic resonance imaging

OBJECTIVE: Fluid-attenuated inversion recovery (FLAIR) has shown promise in the detection of subarachnoid space disease. The exact role of FLAIR in the diagnosis of meningitis has not been established. The purpose of this study was to evaluate FLAIR in the detection of meningitis in comparison with contrast-enhanced T1-weighted images (T1WI) in a blinded-reader study. We describe hyperintense sulci (HS) on FLAIR sequence in meningitis in relation to cerebrospinal fluid (CSF) protein and effective echo time (TE). METHODS: Two observers blinded to clinical information reviewed magnetic resonance (MR) images of patients with the diagnosis of meningitis and those of age-matched controls. The diagnosis was confirmed from chart review and CSF results. FLAIR images were obtained with 2 different TE values of 120 milliseconds and 150 milliseconds. FLAIR changes were correlated with CSF protein concentration and contrast-enhanced T1WI. RESULTS: Twenty-eight MR images of meningitis patients were reviewed. There were 23 abnormal MR images including 16 abnormal FLAIR scans with hyperintense sulci and 23 with leptomeningeal enhancement on contrast-enhanced T1WI. HS on FLAIR correlated with leptomeningeal enhancement on contrast-enhanced T1WI. Four viral and 1 bacterial meningitis had normal MR images (FLAIR and postcontrast TIWI). Two different TE values were used: 120 milliseconds (n = 15) and 150 milliseconds (n = 13). All patients with effective TE of 150 milliseconds. and CSF protein of more than 132 mg/dL had hyperintense sulci whereas patients with effective TE of 120 milliseconds and CSF protein of 257 mg/dL or more had HS. CONCLUSIONS: The sensitivity of contrast-enhanced T1WI was higher than FLAIR. HS on FLAIR correlated with contrast enhancement on T1WI. However, the sensitivity of FLAIR depends on CSF protein concentration threshold for (CSF hyperintensity) for a given effective TE. FLAIR cannot replace contrast-enhanced T1WI in diagnosing meningitis.