Contrast-enhanced Fluid-attenuated Inversion Recovery Research Articles

Diagnostic Utility of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Intracranial Pathologies: Qualitative and Quantitative Analyses

Diagnostic Utility of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Intracranial Pathologies: Qualitative and Quantitative Analyses

Leptomeningeal enhancement of myelin oligodendrocyte glycoprotein antibody-associated encephalitis: uncovering novel markers on contrast-enhanced fluid-attenuated inversion recovery images.

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a newly defined autoimmune inflammatory demyelinating central nervous system (CNS) disease characterized by antibodies against MOG. Leptomeningeal enhancement (LME) on contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) images has been reported in patients with other diseases and interpreted as a biomarker of inflammation. This study retrospectively analyzed the prevalence and distribution of LME on CE-FLAIR images in children with MOG antibody-associated encephalitis (MOG-E). The corresponding magnetic resonance imaging (MRI) features and clinical manifestations are also presented. The brain MRI images (native and CE-FLAIR) and clinical manifestations of 78 children with MOG-E between January 2018 and December 2021 were analyzed. Secondary analyses evaluated the relationship between LME, clinical manifestations, and other MRI measures. Forty-four children were included, and the median age at the first onset was 70.5 months. The prodromal symptoms were fever, headache, emesis, and blurred vision, which could be progressively accompanied by convulsions, decreased level of consciousness, and dyskinesia. MOG-E showed multiple and asymmetric lesions in the brain by MRI, with varying sizes and blurred edges. These lesions were hyperintense on the T2-weighted and FLAIR images and slightly hypointense or hypointense on the T1-weighted images. The most common sites involved were juxtacortical white matter (81.8%) and cortical gray matter (59.1%). Periventricular/juxtaventricular white matter lesions (18.2%) were relatively rare. On CE-FLAIR images, 24 (54.5%) children showed LME located on the cerebral surface. LME was an early feature of MOG-E (P = 0.002), and cases without LME were more likely to involve the brainstem (P = 0.041). LME on CE-FLAIR images may be a novel early marker among patients with MOG-E. The inclusion of CE-FLAIR images in MRI protocols for children with suspected MOG-E at an early stage may be useful for the diagnosis of this disease.

Functional assessment of the dural lymphatic vessels using dynamic contrast MRI in multiple sclerosis.

The discovery of glymphatic function in the human brain has generated interest in waste clearance mechanisms in neurological disorders such as multiple sclerosis (MS). However, noninvasive in vivo functional assessment is currently lacking. This work studies the feasibility of a novel intravenous dynamic contrast MRI method to assess the dural lymphatics, a purported pathway contributing to glymphatic clearance. This prospective study included 20 patients with MS (17 women; age=46.4 [27, 65] years; disease duration=13.6 [2.1, 38.0] years, expanded disability status score (EDSS)=2.0 [0, 6.5]). Patients were scanned on a 3.0T MRI system using intravenous contrast-enhanced fluid-attenuated inversion recovery MRI. Signal in the dural lymphatic vessel along the superior sagittal sinus was measured to calculate peak enhancement, time to maximum enhancement, wash-in and washout slopes, and the area under the time-intensity curve (AUC). Correlation analysis was performed to examine the relationship between the lymphatic dynamic parameters and the demographic and clinical characteristics, including the lesion load and the brain parenchymal fraction (BPF). Contrast enhancement was detected in the dural lymphatics in most patients 2-3min after contrast administration. BPF had a significant correlation with AUC (p<.03), peak enhancement (p<.01), and wash-in slope (p=.01). Lymphatic dynamic parameters did not correlate with age, BMI, disease duration, EDSS, or lesion load. Moderate trends were observed for correlation between patient age and AUC (p=.062), BMI and peak enhancement (p=.059), and BMI and AUC (p=.093). Intravenous dynamic contrast MRI of the dural lymphatics is feasible and may be useful in characterizing its hydrodynamics in neurological diseases.

Diagnostic value of contrast-enhanced 3D FLAIR sequence in acute optic neuritis.

Contrast-enhanced fluid-attenuated inversion recovery (FLAIR) sequence of the brain has the potential for detecting optic nerve abnormality. This study aimed to compare the diagnostic value of whole-brain contrast-enhanced three-dimensional FLAIR with fat suppression (CE 3D FLAIR FS) sequence in detecting acute optic neuritis to dedicated orbit MRI and clinical diagnosis. Twenty-two patients with acute optic neuritis who underwent whole-brain CE-3D-FLAIR FS and dedicated orbit MRI were retrospectively included. The hypersignal FLAIR of the optic nerve on whole-brain CE-3D-FLAIR FS, enhancement, and hypersignal T2W on orbit images were assessed. The optic nerve to frontal white matter signal intensity ratio on CE-FLAIR FS was calculated as maximum signal intensity ratio (SIR) and mean SIR. Twenty-six hypersignals of optic nerves were found on CE-FLAIR FS from 30 pathologic nerves. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CE FLAIR FS brain and dedicated orbital images for diagnosing acute optic neuritis were 77%, 93%, 96%, 65%, and 82% and 83%, 93%, 96%, 72%, and 86%, respectively. Optic nerve to frontal white matter SIR of the affected optic nerves was higher than that of normal optic nerves. Using a cutoff maximum SIR of 1.24 and cutoff mean SIR of 1.16, the sensitivity, specificity, PPV, NPV, and accuracy were 93%, 86%, 93%, 80%, and 89% and 93%, 86%, 93%, 86%, and 91%, respectively. The hypersignal of the optic nerve on whole-brain CE 3D FLAIR FS sequence has qualitative and quantitative diagnostic potential in patients with acute optic neuritis.

Contrast-enhanced fluid-attenuated inversion-recovery (FLAIR) versus contrast-enhanced T1 MRI in the evaluation of intracranial tumors: A comparative study

INTRODUCTION: At most institutions, the favored contrast MR sequence is T1-weighted imaging (T1WI). However, lesion enhancement is occasionally inconspicuous on T1WI.Objective: This study aims to evaluate the diagnostic value of contrast-enhanced FLAIR compared to contrast-enhanced T1WI for intracranial tumors and to offer data for further clinical judgment. METHODS: 88 consecutive cases of intracranial tumors referred for contrast-enhanced brain MRI were analyzed. FLAIR and T1 were used alternately in equal percentages as the first contrast-enhanced sequence to avoid delayed contrast-enhancement effects of the lesions. Six quantitative criteria were considered: lesion-to-white matter contrast ratio (CR) and contrast-to-noise ratio (CNR), lesion-to-gray matter CR and CNR, and lesion-to-cerebrospinal fluid CR and CNR. For qualitative evaluation, two experienced radiologists assessed lesion conspicuity on contrast-enhanced-T1WI and FLAIR sequences using the following three scales: 1, FLAIR superior; 2, sequences equal; 3, T1 superior. RESULTS: For quantitative measurement, the contrast enhanced-FLAIR lesion-to-white matter, lesion-to-cerebrospinal fluid CR, and CNR values were statistically superior to those of the contrast enhanced-T1 weighted images (p = 0.001 in all). However, lesion-to-gray matter CR and CNR were slightly higher on CE-FLAIR, but with no statistically significant difference (p = 0.159, 0.184, respectively). For qualitative evaluation, both radiologists assessed that contrast enhanced-FLAIR images were superior to contrast enhanced-T1 weighted images for the evaluation of lesion conspicuity, especially when it was performed as the second sequence. CONCLUSION: FLAIR sequence was superior or comparable to T1 sequence, especially when performed as a second post-contrast sequence. Using contrast enhanced-FLAIR as a routine MRI sequence will increase diagnostic confidence.

Imaging finding and analysis of brain lymphoma in contrast-enhanced fluid attenuated inversion recovery sequence

ObjectiveThe purpose of this retrospective study was to report and analyze the image findings of contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) sequence of lymphoma in the brain. Material and MethodsThirty-two immunocompetent patients with biopsy-proven diffuse large B-cell type lymphoma in the brain were evaluated with pre-treatment MRI examinations from August 2014 to April 2020. As stereotactic studies on the day of biopsy, FLAIR and T1-weighted axial images were acquired in 2 mm thickness, before and after administrating gadolinium-based contrast agents, with 3.0 Tesla MR machines. Respective subtraction images were also obtained for both CE-FLAIR and contrast-enhanced T1-wieghted image (CE-T1WI) sequences. The imaging findings, especially the enhancement pattern on CE-FLAIR sequence, were analyzed qualitatively and quantitatively, using semi-automatic segmentation. ResultsOn CE-FLAIR images, brain lymphomas were poorly enhanced, while showing peripheral rim enhancement (54 of 58 lesions, 93.1 %) and central enhancing foci (40 of 58 lesions, 69.0 %). Seventy percent of central enhancing foci were correlated to areas with low signal intensity on CE-T1WI. In quantitative analysis, the mean signal intensity of CE-T1WI subtraction was 490.44 and that of FLAIR subtraction was 206.13. The standard deviation of all signal intensity values in CE-T1WI subtraction sequence was 143.45, while that of CE-FLAIR subtraction sequence was 118.41. ConclusionOn CE-FLAIR, brain lymphomas showed relatively poor and homogeneous enhancement, when compared to CE-T1WI. Most brain lymphomas displayed peripheral rim enhancement and central enhancing foci.

GNA11-mutated Sturge-Weber syndrome has distinct neurological and dermatological features.

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by clinical manifestations involving the brain, eye and skin. SWS is commonly caused by somatic mutations in G protein subunit Alpha Q (GNAQ). Five cases of subunit Alpha 11 (GNA11) mutations have been reported. We studied phenotypic features of GNA11-SWS and compared them with those of classic SWS. Within two European multidisciplinary centers we looked for patients with clinical characteristics of SWS and a GNA11 mutation. Clinical and radiological data were collected retrospectively and prospectively. We identified three patients with SWS associated with a somatic GNA11 mutation. All had disseminated capillary malformation (CM) and hyper- or hypotrophy of an extremity. At birth, the CMs of the face, trunk and limbs were pink and patchy, and slowly darkened with age, evolving to a purple color. Two of the patients had glaucoma. All had neurological symptoms and moderate brain atrophy with a lower degree of severity than that classically associated with SWS. Susceptibility-weighted imaging (SWI) and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging demonstrated the best sensitivity to reveal the pial angiomas. We have differentiated two distinct clinical/radiological phenotypes of SWS; GNAQ- and GNA11-SWS. The classic GNAQ-SWS is characterized by a homogeneous dark-red CM, commonly associated with underlying soft tissue hypertrophy. The CM in GNA11-SWS is more reticulate and darkens with time, and the neurological picture is milder. SWI and post-contrast FLAIR sequences appear to be necessary to demonstrate leptomeningeal angiomatosis. Anti-epileptic medication or future targeted therapies may be useful, as in classic SWS.

Contrast-Enhanced Fluid-Attenuated Inversion Recovery in Neuroimaging: A Narrative Review on Clinical Applications and Technical Advances.

While contrast-enhanced fluid-attenuated inversion recovery (FLAIR) has long been regarded as an adjunct sequence to evaluate leptomeningeal disease in addition to contrast-enhanced T1-weighted imaging, it is gradually being used for more diverse pathologies beyond leptomeningeal disease. Contrast-enhanced FLAIR is known to be highly sensitive to low concentrations of gadolinium within the fluid. Accordingly, recent research has suggested the potential utility of contrast-enhanced FLAIR in various kinds of disease, such as Meniere's disease, seizure, stroke, traumatic brain injury, and brain metastasis, in addition to being used for visualizing glymphatic dysfunction. However, its potential applications have been reported sporadically in an unorganized manner. Furthermore, the exact mechanism for its superior sensitivity to low concentrations of gadolinium has not been fully understood. Rapidly developing magnetic resonance technology and unoptimized parameters for FLAIR may challenge its accurate application in clinical practice. This review provides the fundamental mechanism of contrast-enhanced FLAIR, systematically describes its current and potential clinical application, and elaborates on technical considerations for its optimization. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

Contrast Enhanced Fluid-Attenuated Inversion Recovery Versus Contrast Enhanced T1-Spin Echo Magnetic Resonance Imaging in the Evaluation of Infectious Meningitis

Background Infectious meningitis is an infection of the subarachnoid space causing inflammation of the leptomeninges. Early diagnosis is crucial to initiate appropriate therapy, avoid complications, and improve prognosis. Cerebrospinal fluid analysis is important in the diagnosis and is done by performing lumbar puncture with some limitations and complications. MRI plays a role in the diagnosis by depicting abnormal leptomeningeal enhancement. Aim of the study To evaluate the efficiency of contrast-enhanced fluid-attenuated inversion recovery compared with contrast-enhanced T1 spin echo in the diagnosis of infectious meningitis. Patients and Methods A prospective analytical study of diagnostic tests was conducted. Brain MRI was done using a 3-Tesla system. Gadolinium was used as contrast material. The final diagnosis of meningitis was made based on cerebrospinal fluid analysis. Validity parameters, predictive values, and diagnostic accuracy for both sequences were calculated and compared to each other. Quantitative and qualitative analysis was performed. Results Fifty-six patients were involved (31 males and 25 females) in this study, and they ranged from 15 to 68 years in age. Cerebrospinal fluid analysis was positive in 41 patients and negative in 15. Contrast enhanced–fluid attenuated inversion recovery has higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy compared with contrast enhanced–T1 spin echo. The mean net meningeal enhancement is significantly higher in contrast enhanced–fluid attenuated inversion recovery. Substantial interobserver agreement between the two sequences was observed. Conclusion Contrast enhanced–fluid attenuated inversion recovery is superior to contrast enhanced–T1 spin echo in the diagnosis of infectious meningitis. .

Role of contrast-enhanced FLAIR MRI in diagnosis of intracranial lesions

BackgroundMR imaging plays a significant role in detection and characterization of different brain diseases. The role of the post-contrast T1-weighted image magnetic resonance imaging (T1W MRI) sequence has been widely established in previous studies and clinical practice. In this study, we aim to share our experience as regards the added value of contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) sequence in the diagnosis of various intracranial pathological conditions and evaluate its usefulness in comparison with post-contrast T1W images.ResultsBased on the final radiological diagnosis, the total cases were subdivided into three categories, and the majority of our cases were tumors (81.2%), followed by multiple sclerosis (11.8%), and the least was central nervous system infection (7.1%). CE-FLAIR showed superior enhancement in 35 cases (50.7) and equal enhancement in 25 cases (36.3%). However, it showed less enhancement than post-contrast T1W images in 9 cases (13%). Excellent inter-observer agreement (97.65%) was noted. Regarding lesion conspicuity, good delineation was found in the majority of cases (64.7%), fair delineation in 12.9%, and no delineation in 22.4%. A statistically significant difference was found in signal intensity of lesion between pre- and post-contrast FLAIR sequences. Contrast to background ratio was statistically significant in CE FLAIR images in comparison to CE T1 images.ConclusionCE-FLAIR imaging should be used as a routine or adjunctive sequence to CE-T1WI to enhance early detection and increase the diagnostic confidence in MRI examination of different brain pathological conditions.

Quantitative analysis of cochlear signal intensity on three-dimensional and contrast-enhanced fluid-attenuated inversion recovery images in patients with Meniere's disease: Correlation with the pure tone audiometry test

The purpose of this study was to correlate the quantitative analysis of cochlear signal intensity (SI) on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and contrast-enhanced (CE) 3D-FLAIR images with results of the pure tone audiometry (PTA) test in patients with Meniere's disease (MD). Over a 3-year period, 123 patients with MD underwent 3-Tesla (3 T) temporal magnetic resonance imaging (MRI), including 3D-FLAIR and CE-FLAIR sequences. The SI of membranous labyrinth of the cochlea in both ears of each patient was measured by drawing a region of interest (ROI) with a seed growing technique. The correlation between measured cochlear SIs on 3D-FLAIR and CE-FLAIR images, contrast enhancement index (CEI), and contrast enhancement ratio (CER) and clinical findings and pre- and post-treatment PTA results were assessed. Cochlear signal ratios of symptomatic ears on 3D-FLAIR and CE-FLAIR images were significantly higher than those of asymptomatic ears (P < 0.001). The area under the curve, from the receiver operating characteristic curve of cochlear SIs on 3D-FLAIR and CE-FLAIR images for discrimination between symptomatic and asymptomatic ears, was 0.729 and 0.728, respectively. Cochlear SIs on 3D-FLAIR and CE-FLAIR images were significantly correlated with patients' sex (P < 0.05 and P < 0.01, respectively), symptomatic ear (both P < 0.0001), and pre-treatment PTA (P < 0.0001 and P < 0.005, respectively), but were not significantly correlated with patients' age, post-treatment PTA or hearing threshold level at 0.5, 1.0, 2.0, or 4.0 kHz. Quantitative analysis of cochlear SI on 3D-FLAIR and CE-FLAIR images may be a helpful diagnostic adjunct for MD, but may be of little value in predicting the prognosis of MD.

Multiparameter MRI Predictors of Long-Term Survival in Glioblastoma Multiforme

Standard-of-care multiparameter magnetic resonance imaging (MRI) scans of the brain were used to objectively subdivide glioblastoma multiforme (GBM) tumors into regions that correspond to variations in blood flow, interstitial edema, and cellular density. We hypothesized that the distribution of these distinct tumor ecological “habitats” at the time of presentation will impact the course of the disease. We retrospectively analyzed initial MRI scans in 2 groups of patients diagnosed with GBM, a long-term survival group comprising subjects who survived >36 month postdiagnosis, and a short-term survival group comprising subjects who survived ≤19 month postdiagnosis. The single-institution discovery cohort contained 22 subjects in each group, while the multi-institution validation cohort contained 15 subjects per group. MRI voxel intensities were calibrated, and tumor voxels clustered on contrast-enhanced T1-weighted and fluid-attenuated inversion-recovery (FLAIR) images into 6 distinct “habitats” based on low- to medium- to high-contrast enhancement and low–high signal on FLAIR scans. Habitat 6 (high signal on calibrated contrast-enhanced T1-weighted and FLAIR sequences) comprised a significantly higher volume fraction of tumors in the long-term survival group (discovery cohort, 35% ± 6.5%; validation cohort, 34% ± 4.8%) compared with tumors in the short-term survival group (discovery cohort, 17% ± 4.5%, P < .03; validation cohort, 16 ± 4.0%, P < .007). Of the 6 distinct MRI-defined habitats, the fractional tumor volume of habitat 6 at diagnosis was significantly predictive of long- or short-term survival. We discuss a possible mechanistic basis for this association and implications for habitat-driven adaptive therapy of GBM.

Gadolinium Leakage in Ocular Structures Is Common in Lacunar Infarction.

Background and Purpose- We investigated the frequency and pattern of blood-brain barrier, as well as blood-retina barrier, impairment in acute lacunar infarction as demonstrated by hyperintense acute reperfusion marker and gadolinium leakage in ocular structures (GLOS), respectively, on fluid-attenuated inversion recovery images. Methods- Acute lacunar infarction patients who underwent repeated magnetic resonance imaging after intravenous contrast agent administration were identified and the presence of GLOS in the anterior chamber and vitreous body and hyperintense acute reperfusion marker noted on fluid-attenuated inversion recovery. Results- Overall, 24 acute lacunar infarction patients (median age 64.5 years; interquartile range, 54-78 years) were included. On contrast-enhanced fluid-attenuated inversion recovery, GLOS was observed in 11 (45.8%) patients: in 4 (16.7%) in the anterior chamber only and in 7 (29.2%) in the anterior chamber and vitreous body. In all patients, GLOS was bilateral and symmetrical. In patients with GLOS in the anterior chamber only, the time between initial and follow-up magnetic resonance imaging was significantly shorter (7.5 [interquartile range, 4.25-11.5] hours) compared with patients with GLOS in the anterior chamber and vitreous body (28 [interquartile range, 10-43] hours; P=0.047). Hyperintense acute reperfusion marker could not be demonstrated in any of the patients. Conclusions- In acute lacunar infarction patients, unlike hyperintense acute reperfusion marker, GLOS is a frequent finding and shows a similar temporal evolution like in larger ischemic stroke.

Differentiation Between Intralabyrinthine Schwannoma and Contrast-enhancing Labyrinthitis on MRI: Quantitative Analysis of Signal Intensity Characteristics.

Distinguishing intralabyrinthine schwannoma (ILS) from labyrinthitis is crucial in deciding patient management between surgery and medication; however, the clinical and radiological differentiation between ILS and labyrinthitis is difficult, especially when labyrinthitis shows contrast-enhancement mimicking ILS on magnetic resonance imaging (MRI). This study aimed to evaluate the quantitative characteristics of signal intensity on 3T MRI for differentiating ILS from contrast-enhancing labyrinthitis (CEL). Retrospective study. Tertiary referral center. Between July 2003 and June 2017, 9 subjects diagnosed with ILS (16 MRI cases) and 9 subjects diagnosed with CEL (9 MRI cases) were enrolled in the study. Normalized signal intensity on contrast-enhanced T1-weighted image (nCE-T1), normalized signal intensity on T2-weighted image (nT2), and normalized signal intensity on contrast-enhanced fluid-attenuated inversion recovery image (nFLAIR) were measured and compared between ILS and CEL. The diagnostic performance of these values was assessed using receiver operating characteristic (ROC) analysis. In ILS, the nCE-T1 and the nT2 were significantly higher and lower, respectively, than in CEL (all, p < 0.05); and the nFLAIR did not significantly differ (p > 0.05). The maximal nCE-T1 achieved the highest area under the curve (AUC) in differentiating ILS and CEL, followed by the mean nCE-T1, the mean nT2, and the maximal nT2. Combination of the nCE-T1 and the nT2 showed higher AUC than the nCE-T1 alone, but without statistical significance (p = 0.340). Quantitative measurement of the signal intensity on MRI can be a viable imaging tool for differentiating ILS from CEL.

Contrast-enhanced fat-suppressed FLAIR for the characterization of leptomeningeal inflammation in optic neuritis

Background: Leptomeningeal contrast enhancement on fluid-attenuated inversion recovery (FLAIR) images has been reported in patients with multiple sclerosis and interpreted as a biomarker of inflammation. In this study, we sought to evaluate this phenomenon in patients with optic neuritis (ON). Methods: A total of 42 patients with suspected ON were included in this prospective study and underwent a dedicated study magnetic resonance imaging (MRI) protocol including native and contrast-enhanced fat-suppressed thin-section axial and coronal FLAIR images on an 1.5 T magnetic resonance (MR) system. Results: After diagnostic workup, 34 patients with final diagnosis of ON were analyzed in detail. On contrast-enhanced fat-suppressed FLAIR images, 25 (73.5%) patients with ON demonstrated perioptic leptomeningeal enhancement, and in 3 (8.8%) patients, this was even the only pathological MRI finding. In comparison, patients with perioptic leptomeningeal enhancement on contrast-enhanced fat-suppressed FLAIR images had a higher prevalence of additional hyperintense brain lesions (p = 0.022) as well as cerebrospinal fluid (CSF)-specific oligoclonal bands (p = 0.013) than patients without. Conclusion: Perioptic leptomeningeal contrast enhancement on fat-suppressed FLAIR images is a novel marker in ON and possibly reflects a leptomeningeal inflammatory process preceding or accompanying ON. Thin-section contrast-enhanced fat-suppressed FLAIR images might be a useful addition in MRI protocols for patients with suspected ON.

Contrast-enhanced fluid-attenuated inversion recovery magnetic resonance imaging was useful in detecting inflammation of the meninges in neuropsychiatric systemic lupus erythematosus: a case report

A 49-year-old woman was admitted to our hospital with recurrent episodes of paresthesia attacks evolving in 5 to 15 minutes from the left hand to the left leg through the left trunk. Neurological examination revealed cortical sensory disturbance in her left hand. Although contrast-enhanced T1-weighted MRI findings were unremarkable, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) MRI revealed abnormal leptomeningeal enhancement over the sulcus of the parietal lobe, including the sulcus around the postcentral gyrus. Because we assumed the cause of the recurrent sensory attack to be meningeal inflammation around the primary somatosensory cortex, we treated this patient by increasing the dose of prednisolone. The increase in prednisolone dose completely resolved the symptom, as well as the abnormal leptomeningeal enhancement on contrast-enhanced FLAIR MRI. In patients with suspected meningeal inflammation, contrast-enhanced FLAIR MRI, which is reported to be more sensitive than contrast-enhanced T1-weighted MRI in detecting subtle abnormal leptomeningeal enhancement, should be the modality of choice.

Utility of contrast-enhanced fluid-attenuated inversion recovery in magnetic resonance imaging of intracranial lesions

Aim: The aim of this study is to determine utility of contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging by comparing results with contrast-enhanced T1-weighted imaging (T1WI) in various intracranial lesions. Materials and Methods: Forty-nine patients with a known intracranial lesion or with clinical suspicion underwent the gadolinium-enhanced magnetic resonance (MR) imaging using 1.5T. Postcontrast axial, coronal, and sagittal T1 fat-saturated, axial FLAIR images were acquired after administration of gadobenate dimeglumine. The MR imaging parameters for the postcontrast T2-FLAIR images were 6000–9000/90–110/1845–2030 ms/150 (repetition time/echo time/inversion time/flip angle), and the acquisition time was 2 min 12 s. All images were acquired with a section thickness of 5 mm, an intersection gap of 2 mm, and a field of view of 256 mm × 144 mm. The images were transferred to a workstation and reviewed. Results: We found that postcontrast FLAIR images are useful by showing better meningeal involvement in various pathologies and enhancement of the solid component in intra-axial lesions. However, it was not much helpful in extra-axial lesions and lesions with mild postcontrast enhancement and lesions with perilesional edema. Conclusion: Postcontrast FLAIR is a useful adjunct to postcontrast T1W images in equivocal cases and for additional information.

髄膜炎の診断, 治療方針の策定にMRI造影fluid-attenuated inversion recovery (FLAIR) が有用であった1乳児例

髄膜炎の診断, 治療方針の策定にMRI造影fluid-attenuated inversion recovery (FLAIR) が有用であった1乳児例

Blood-brain barrier breakdown in reversible cerebral vasoconstriction syndrome: Implications for pathophysiology and diagnosis.

Diagnosis of reversible cerebral vasoconstriction syndrome (RCVS) is currently based on luminographic findings of vasoconstriction. In addition to vasoconstriction, the blood-brain barrier (BBB) breakdown has been postulated as a central mechanism of RCVS. Our aim was to document BBB breakdown in patients with RCVS and its role for the pathophysiology-based diagnosis of RCVS. We prospectively recruited 72 consecutive patients with thunderclap headache who did not have aneurysmal subarachnoid hemorrhage from April 2015 to July 2016 at the Samsung Medical Center. Based on the International Classification of Headache Disorders-3 beta criteria and neuroimaging, patients were classified as having RCVS (n = 41; "definite" in 29 imaging-proven patients and "probable" in 12 imaging-negative patients), other secondary causes (n = 7), and thunderclap headache of undetermined cause (n = 24). BBB breakdown was evaluated using contrast-enhanced fluid-attenuated inversion recovery magnetic resonance imaging. BBB breakdown was documented in 20 (69.0%) patients with definite RCVS, 3 (25.0%) patients with probable RCVS, and none with other secondary causes. BBB breakdown was present in RCVS patients with (n = 4) and without (n = 19) concomitant posterior reversible encephalopathy syndrome. In patients with RCVS, the extent of BBB breakdown was independently associated with neurological complications (multivariate odds ratio = 1.48 per 1 territorial increase, 95% confidence interval = 1.04-2.12, adjusted p = 0.032). Three (12.5%) patients with thunderclap headache of undetermined cause were newly classified as having RCVS by the presence of BBB breakdown. This is the first study to show BBB breakdown in patients with RCVS. This finding might broaden our understanding of the pathophysiology and clinical spectrum of RCVS. Ann Neurol 2017;81:454-466.

Characteristic MRI findings in hyperglycaemia-induced seizures: diagnostic value of contrast-enhanced fluid-attenuated inversion recovery imaging

To describe characteristic magnetic resonance imaging (MRI) abnormalities in hyperglycaemia-induced seizures, and evaluate the diagnostic value of contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging. Possible underlying mechanisms of this condition are also discussed. Eleven patients with hyperglycaemia-induced seizures and MRI abnormalities were retrospectively studied. Clinical manifestations, laboratory findings, MRI findings, and clinical outcomes were analysed. All patients, except one, presented with focal seizures, simple or complex partial seizures, or negative motor seizures. All patients had long-standing uncontrolled diabetes mellitus. The MRI abnormalities observed acutely were focal subcortical hypointensities on T2-weighted imaging and FLAIR imaging in all patients with overlying cortical gyral T2 hyperintensities in five. Focal overlying cortical or leptomeningeal enhancement on contrast-enhanced T1-weighted imaging or contrast-enhanced FLAIR imaging was observed in all patients. Contrast-enhanced FLAIR imaging was superior to contrast-enhanced T1-weighted imaging for detecting characteristic cortical or leptomeningeal enhancement. Diffusion-weighted imaging showed mildly restricted diffusion in four of five patients with cortical gyral T2 hyperintensity. In nine patients, the lesions were localised in the parietal or parieto-occipital lobes. The other two patients showed localised precentral gyral lesions. After treatment, the neurological symptoms, including the seizures, improved in all patients. On clinical recovery, the subcortical T2 hypointensity, gyral or leptomeningeal enhancement, and overlying cortical T2 hyperintensities resolved. Recognition of these radiological abnormalities in patients with hyperglycaemia-induced seizures is important in restricting unwarranted investigations and initiating early therapy. These patients generally have a good prognosis.