FLAIR Hyperintensity Research Articles

Multinodular and Vacuolating Neuronal Tumor of the Cerebrum (MVNT): A case series and review of the literature

Background and purposeMultinodular and Vacuolating Neuronal Tumor of the cerebrum (MVNT) is a benign –seizure associated– lesion affecting mostly adults. This new entity has been included in the 2016 World Health Organization classification of tumors of the central nervous system.Its pathologic hallmark consist of a subcortical cluster of nodular lesions located on the subcortical white matter.We aim to report a series of cases of presumed MVNT observed in our institution and review the literature. Materials and methodsIn this retrospective study, a search was performed on our hospital information system. Sixteen cases were included. Demographic, clinical and radiological features were detailed in a table.All patients had an MRI acquired either on a 1.5 or a 3 Tesla scanner. Sequences performed included T1, T2, GRE/SWI, T2 FLAIR and DWI. Gadolinium enhanced T1-WI wer available in 11 patients and follow-up MRI were available in 7 patients. ResultsPatient ages ranged from 16 to 77 years (mean 42 years). Seizure and non-focal headache were by far the most common neurological complaints for which MRI was requested. All lesions consisted of clusters of multiple, discrete, round or ovoid, intra-axial, FLAIR and T2-WI hyperintense nodules. Follow-up MRI scans showed no changes between studies. ConclusionsMVNT is a benign, stable lesion that exhibits a typical radiological pattern that most of the times sufficed to arrive to a diagnosis, without the need of pathological confirmation. We confirm that our demographic, clinical and radiological findings are in accordance with those published in international literature.

Diffusion tensor imaging of the normal-appearing deep gray matter in primary and secondary progressive multiple sclerosis.

Despite strongly overlapping patterns of clinical and histopathologic findings in primary and secondary progressive multiple sclerosis, differences concerning motor symptoms, central nervous system inflammation, atrophy, and demyelination that cannot be accounted for by lesion load alone remain to be elucidated. To evaluate the normal-appearing deep gray matter in patients with primary and secondary progressive multiple sclerosis, diffusion tensor imaging was used in this study. In 14 multiple sclerosis patients with primary and secondary progressive multiple sclerosis, axial echo-planar single-shot diffusion tensor imaging sequences with 32 diffusion-encoding directions and axial FLAIR sequences were acquired on a 3T system using an eight-channel SENSE head coil. FLAIR hyperintense multiple sclerosis lesions were outlined semi-automatically and normal-appearing deep gray matter was outlined manually (caudate nucleus, globus pallidus, putamen, thalamus, substantia nigra, and red nucleus). Fractional anisotropy and mean diffusivity values within the normal-appearing deep gray matter for the two groups were compared. Interhemispheric differences in mean diffusivity values (but not in fractional anisotropy), were significantly higher in primary progressive multiple sclerosis than in secondary progressive multiple sclerosis for the substantia nigra ( P = 0.04) and the putamen ( P = 0.021). Volumes, mean diffusivity, or fractional anisotropy of the remaining normal-appearing deep gray matter did not differ significantly. This study showed a higher interhemispheric difference in the mean diffusivity in the substantia nigra and putamen in patients with primary progressive multiple sclerosis than in those with secondary progressive multiple sclerosis. These changes may represent edema, as well as axonal and myelin loss that can affect the normal-appearing deep gray matter of the two hemispheres differently and may point to differences in the laterality of motor symptoms.

Synthetic T2 mapping is correlated with time from stroke onset: a future tool in wake-up stroke management?

FLAIR-DWI mismatch is an effective method to select eligible wake-up stroke (WUS) patients for intravenous thrombolysis, but shows limitations in the case of subtle FLAIR hyperintensities. T2 mapping is a quantitative method, directly generated from synthetic MRI, which provides T2 relaxation times. We aimed to assess the correlation between T2 values and onset time in acute stroke patients. We prospectively included stroke patients in the 4.5-h window undergoing brain MRI including MAGnetic resonance Image Compilation (MAGiC) from March to October 2017. T2 relaxation times and FLAIR signal intensities were measured in ischemic and contralateral nonischemic regions to calculate FLAIR signal intensity ratio (rSI), difference, and ratio of T2 values. Correlation analysis with time from the onset was achieved using Pearson or Spearman correlation coefficient (ρ) test. Forty-two patients were included. The strongest correlation with the time from onset was the difference in T2 relaxation times (ρ = 0.71; CI95% = [0.48; 0.85]), followed by the ratio (ρ= 0.65; CI95% = [0.37; 0.82]) and the absolute T2 relaxation time (ρ= 0.4; CI95% = [0.06; 0.66]), whereas the FLAIR rSI showed the weakest correlation (ρ = 0.18; CI95% = [- 0.16-0.51]). The difference and ratio in T2 relaxation times were correlated with the onset time in stroke patients in the 4.5-h window. T2 mapping generated from synthetic MRI may become a relevant tool to select WUS patients with subtle FLAIR hyperintensities. Given that no definitive statement can be made about its usefulness in the 4.5-h windows, further study including patients with an onset time > 4.5h is required. • The difference and ratio in T2 relaxation times are each individually correlated with the time from stroke onset in the 4.5-h window. • FLAIR rSI showed a poor correlation with the time from stroke onset. • T2 mapping, directly generated from synthetic MRI, may be a suitable quantitative marker to select safely WUS patients with subtle FLAIR hyperintensities for intravenous thrombolysis.

MOG antibody seropositive aseptic meningitis: A new clinical phenotype

The spectrum of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) associated demyelination is evolving. Our case report describes a unique clinical presentation of aseptic meningitis with demyelinating lesions of the brain resembling acute disseminated encephalomyelitis and MOG-Ab seropositivity. A 22-year-old lady presented with history of fever of one week duration followed by headache, vomiting and neck stiffness. She had bilateral papilledema and signs of meningeal irritation. Neuroimaging revealed T2 and FLAIR hyperintense lesions in the right caudate, temporal lobe and left insula with enhancement on gadolinium contrast along with leptomeningeal enhancement. An extensive search for infectious and inflammatory etiology was negative while serum was positive for MOG-Abs tested twice at an interval of 12 days. She showed remarkable clinical-radiological resolution with steroids and has remained symptom free on follow up.

MON-430 To B, or Not to B

Background: Wernicke’s encephalopathy (WE) is an acute neuropsychiatric derangement caused by Vitamin-B1 (Thiamine) deficiency. Clinical Case: A 49-year-old Hispanic woman was admitted with abdominal pain, intractable nausea and vomiting, two weeks following a diagnosis of infectious mononucleosis. An upper endoscopy was negative. She was discharged on symptomatic treatment with pantoprazole and sucralfate. Four weeks later, she presented with worsening symptoms and a new complaint of blurry vision. Physical exam revealed decreased visual acuity with dysconjugate gaze. Brain CT and MRI were unremarkable. Outpatient ophthalmology consultation was advised. Four days later, she reported to the ophthalmologist with worsening vision, headaches, distal tingling/numbness, gait instability, mildly impaired cognition. The ocular examination revealed visual acuity restricted to counting fingers, large central scotoma, restricted abduction/adduction, and bilateral horizontal and vertical nystagmus. She was readmitted with a suspicion of Miller-Fischer variant of Guillain-Barre. She denied alcohol consumption, tobacco or recreational drug use. She reported 40lb weight loss in 5 weeks. On physical exam, strength was normal, with decreased distal vibration sensation, absent ankle reflexes and ataxic gait. Anti-GQ1b antibodies and CSF studies were unremarkable. Further testing revealed negative/normal HIV antigen/antibody, vitamin B12 level, glycohemoglobin A1c, Lyme antibodies, angiotensin converting enzyme, ANA and serum protein electrophoresis. Serial brain MRI showed FLAIR hyperintensity in both thalami, dorsal medial brainstem along the mammillary bodies, and the third periventricular white matter. Thiamine deficiency was strongly suspected. A vitamin-B1 level was sent out and she was empirically started on large dose IV thiamine. The thiamine level returned very low at 24nmol/l (70-180nmol/l) confirming WE. Her symptoms began to resolve within 12 hours of thiamine infusion. Given no preceding history of alcoholism, a workup for other causes of thiamine deficiency was pursued. Celiac serology, stool pancreatic elastase, CT chest/abdomen/pelvis, colonoscopy were unremarkable. Thiamine deficiency was attributed to her prolonged history of vomiting, decreased intake, in combination with the recently prescribed pantoprazole and sucralfate which contributed to malabsorption. Discussion: WE is typically related to alcoholism. From 1867-2014, 623 cases of WE were described in non-alcoholics. We should have a high index of suspicion for thiamine deficiency in situations of unbalanced nutrition that has lasted for 2 to 3 weeks to avoid misdiagnosis of the life-threatening WE or irreversible brain damage (Korsakoff syndrome). This should prompt immediate administration of large doses of thiamine parenterally even prior to laboratory confirmation.

Non-Contrast-Enhancing Tumor: A New Frontier in Glioblastoma Research.

There is a growing understanding of the prognostic importance of non-contrast-enhancing tumor in glioblastoma, and recent attempts at more aggressive management of this component using neurosurgical resection and radiosurgery have been shown to prolong survival. Optimizing these therapeutic strategies requires an understanding of the features that can distinguish non-contrast-enhancing tumor from other processes, in particular vasogenic edema; however, the limited and heterogeneous manner in which it has been defined in the literature limits clinical translation. This review covers pertinent literature on our growing understanding of non-contrast-enhancing tumor and focuses on key conventional MR imaging features for improving its delineation. Such features include subtle differences in the degree of FLAIR hyperintensity, gray matter involvement, and focal mass effect. Improved delineation of tumor from edema will facilitate more aggressive management of this component and potentially realize associated survival benefits.

Tumefactive Multiple Sclerosis Clinically Mimicking Acute Stroke and Lesional Migration Along the Biopsy Tract: A Case Report

Tumefactive multiple sclerosis is a form of demyelinating disease which patient can present with acute stroke. We reported a case of a 49-year-old woman with well controlled hypertension, who presented with right hemiplegia 15 hours prior to admission. The initial diagnosis of acute stroke was made. Emergency computed tomography showed hypodense lesion at the left lentiform nucleus and posterior limb of the left internal capsule. The magnetic resonance imaging (MRI) study showed hyperintense FLAIR lesion in the left lentiform nucleus, left internal capsule, left thalamus, and periventricular area of the left frontoparietal region, some areas of restricted diffusion and inhomogeneous enhancement. The MR spectroscopy (MRS) of the lesion showed increased choline peak, decreased creatine and NAA peaks, and maximal choline to creatine ratio 2.25. Her symptoms deteriorated with progressive headache and motor aphasia. The follow up MRI showed extension of the inhomogeneous enhancing lesion along the biopsy tract at the left frontal lobe with the enhancing and MR spectra pattern similar to the lesion. The craniotomy with left frontal lesion excision included the mass and the biopsy tract was done. The lesion showed acute and chronic inflammatory cell infiltration with macrophages, necrotic tissue and reactive gliosis. The further pathological worked up demonstrated foci of demyelination with relative axonal preservation, numerous CD68+ macrophages with intracyto-plasmic Luxol fast blue(+) myelin debris. Perivascular and parenchymal CD3+ T-cells were identified, especially in demyelinating foci. These findings supported the diagnosis of tumefactive multiple sclerosis. Her conditions were improved after treating with pulse methylprednisolone and intravenous immunoglobulin (IVIG). Follow up MRI study 4 months after treatment revealed almost resolution of the preexisting inhomogeneous enhancing lesion.

Coexistent Vestibular Schwannoma and Creutzfeldt–Jakob Disease: Recognition and Infection Control

We describe the first known case of coexistent vestibular schwannoma (VS) and Creutzfeldt-Jakob disease (CJD). Our objectives are to use this case as a general lesson for the subspecialist otolaryngologist to remain vigilant to alternative diagnoses, and to specifically improve understanding of the diagnosis and management of CJD as relevant to the practice of otolaryngology and skull base surgery. Retrospective case review performed in June 2016 at an academic, tertiary, referral center. A 55-year-old man presents with one month of worsening disequilibrium and short-term memory loss. Magnetic resonance imaging (MRI) (T1, T2) identified a 4 mm left VS which was then surgically resected. Postoperatively, his neurological status decline continued, and subsequent MRI identified patterns of FLAIR hyperintensity and diffusion restriction consistent with CJD. While CSF analysis (tau and 14-3-3) and EEG was inconclusive, serial imaging and the clinical course were highly suggestive of CJD. A probable diagnosis was made, surgical instruments quarantined, and infection control involved to minimize transmission risk. The patient died 6 months after symptom onset. Patients with CJD may initially present with otolaryngologic symptoms. MRI signal abnormality in the basal ganglia on diffusion weighted imaging and FLAIR sequences in conjunction with physical findings and clinical course may help make a probable diagnosis CJD. Prions are resistant to traditional sterilization and additional measures must be taken to prevent iatrogenic transmission. Level 4-Case series.

Acute cerebellitis in paediatric patients: Our experience

IntroductionAcute cerebellitis is a rare inflammatory disease with a highly variable clinical course that ranges from benign self-limiting symptoms to a fulminant presentation associated with a high risk of death due to compression of the posterior fossa, acute hydrocephalus, and intracranial hypertension. MethodsWe reviewed clinical, laboratory, and radiological findings from children diagnosed with acute cerebellitis between May 2007 and November 2016. We analysed treatments and clinical and radiological progression. ResultsNine children met the diagnostic criteria for cerebellitis. Headache, vomiting, and drowsiness were the most frequent initial symptoms; ataxia, dysarthria, and dysmetria were the most common cerebellar signs. Cerebellitis was diagnosed with magnetic resonance imaging, which revealed cerebellar involvement (unilateral or bilateral); computerised tomography images either were normal or showed indirect signs such as triventricular hydrocephalus due to extrinsic compression of the aqueduct of Sylvius. Corticosteroids were the most commonly used treatment (6 patients). One patient required surgery due to triventricular hydrocephalus. Eight patients recovered completely, whereas the ninth displayed neurological sequelae. ConclusionsCerebellitis is a medical and surgical emergency; diagnosis requires a high level of suspicion and an emergency brain magnetic resonance imaging study. It is a clinical-radiological syndrome characterised by acute or subacute encephalopathy with intracranial hypertension and cerebellar syndrome associated with T2-weighted and FLAIR hyperintensities in the cerebellar cortex (unilaterally or bilaterally) and possible triventricular dilatation. Treatment is based on high-dose corticosteroids and may require external ventricular drain placement and decompressive surgery.

Interesting MRI finding in SSPE – a case report

Introduction: 10% of the subacute sclerosing panencephalitis (SSPE) presents with atypical features. Aim: SSPE is rare chronic encephalitis caused by persistent infection with defective measles virus. Characteristic MRI findings include signal changes (T2W and FLAIR hyperintensities) in bilateral occipital and parietal regions involving both gray and white matter. Early involvement of cerebellum and brainstem is not common. Case study: A 17-year-old male presented with complaints of recurrent seizures, slow walking, and behavioral abnormality. Neurological examination revealed cogwheel rigidity in all four limbs. MRI of the brain revealed asymmetrical cortical and subcortical altered signal intensities (T2W and FLAIR hyperintensity and T1W hypointensity) involving temporal and occipital lobes bilaterally (left more than right) with diffuse atrophy of cerebrum and cerebellum. Results and discussion: Early onset extrapyramidal features, seizures without myoclonus with MRI finding of posterior predominant asymmetrical cortical and subcortical signal abnormality is uncommon in SSPE. Conclusions: A high index of clinical suspicion for SSPE has to be maintained in patients haling from endemic areas, unvaccinated individuals presenting with seizures, behavioral abnormality, and extrapyramidal features.

MRI Abnormalities Predominate in the Bottom Part of the Sulcus with Type II Focal Cortical Dysplasia: A Quantitative Study.

Type II focal cortical dysplasia is a common histopathological substrate in focal epilepsy. This study explored the spatial distribution of abnormal findings on MR imaging across the sulcus with type II focal cortical dysplasia using quantitative MR imaging postprocessing techniques. The morphometric analysis program and normalized FLAIR signal intensity analysis were applied to retrospectively analyze the MR imaging data of 58 patients with histopathologically confirmed type II focal cortical dysplasia. We divided the dysplastic sulcus into the bottom and nonbottom parts. Then spatial distribution types 1, 2, and 3 were arbitrarily defined as the abnormal findings on MR imaging (z-value > threshold) located in the bottom part, both the bottom and nonbottom parts, and the nonbottom part, respectively. For type 2, the mean z-values and standardized volumes of abnormal findings on MR imaging were compared between the bottom and nonbottom parts. Abnormal findings on MR imaging were detected by quantitative techniques in 42 of 58 enrolled patients. Among these 42 patients, 38 and 26 patients showed gray-white matter junction blurring and cortical FLAIR hyperintensity, respectively, which were the 2 most common abnormal MR imaging features. Gray-white matter junction blurring manifested as types 1, 2, and 3 in 24, 13, and 1 patient, respectively, and the corresponding counts for cortical FLAIR hyperintensity were 12, 13, and 1 patient. For the 2 most common abnormal findings on MR imaging spatially manifested as type 2, higher mean z-values and larger corresponding standardized volumes of abnormalities were found in the bottom part. Abnormal findings on MR imaging predominate in the bottom part of the sulcus with type II focal cortical dysplasia, which indicates that this malformation is bottom-of-sulcus-rooted.

Selective middle cerebral artery occlusion in the rabbit: Technique and characterization with pathologic findings and multimodal MRI

BackgroundA reliable animal model of ischemic stroke is vital for pre-clinical evaluation of stroke therapies. We describe a reproducible middle cerebral artery (MCA) embolic occlusion in the French Lop rabbit characterized with multimodal MRI and histopathologic tissue analysis. New methodFluoroscopic-guided microcatheter placement was performed in five consecutive subjects with angiographic confirmation of MCA occlusion with autologous clot. Multimodal MRI was obtained prior to occlusion and up to six hours post after which repeat angiography confirmed sustained occlusion. The brain was harvested for histopathologic examination. ResultsAngiography confirmed successful MCA catheterization and durable (>6 h) MCA occlusion in all animals. There was increase of ADC volume over time and variable final core volume presumably related to individual variation in collateral flow. FLAIR hyperintensity indicative of cytotoxic edema and parenchymal contrast enhancement reflective of blood brain barrier disruption was observed over time. Tissue staining of the ischemic brain showed edema and structural alterations consistent with infarction. Comparison with existing methodsThis study describes a technique of selective catheterization and embolic occlusion of the MCA in the rabbit with MRI characterization of evolution of ischemia in the model. ConclusionsWe demonstrate the feasibility of a rabbit model of embolic MCA occlusion with angiographic documentation. Serial MR imaging demonstrated changes comparable to those observed in human ischemic stroke, confirmed histopathologically.

864. Therapeutic Immunosupression to Treat Rabies Encephalitis

BackgroundRabies is nearly universally fatal with about 60,000 annual deaths globally; <0.1% cases survive. Reports of therapeutic coma leading to survival are outnumbered by reports of failure. On the basis of personal discussions with a leading rabies expert (Dr Rodney Willoughby), we hypothesized that limiting CNS immune response based on CSF antibody titre (ABT) might prove useful. We report on successful use of immunosuppression in 1 patient.MethodsA 26-year-old male was admitted with 2-day history of flu-like syndrome. He had category III dog bite on face 17 days prior. RIG was not given due to nonavailability; he had received ARV day 0, 3, 7, and 14 on time. On 4th day of admission (day 0), neurological features started—difficulty in walking and diplopia; hydrophobia was noted. Working diagnosis of rabies was made. MRI brain on day 1 showed subtle abnormal T2 and flair hyper intensities in pons, medulla, and left hippocampus. CSF (day 1) showed 105 cells; all lymphocytes. The RFFIT serum and CSF ABTs and rabies PCRs are tabulated below. Since ADEM was a possibility, he was begun on IVIg. Work up for other viral encephalitis was negative. Repeat CSF ABT on day 6 confirmed rabies. Postulating risk of death due to cerebral edema due to CNS immune response, dexamethasone (dexa) 6 mg/kg/day in 4 divided doses was begun on day 8. Serial MRI and CSF were done. Dexa taper was done based on MRI and CSF ABT. Intensive supportive care was given.ResultsMRI on day 9 and day 12 showed no cerebral edema. Dexa taper was started from day 13 by half every alternate day; it was given till day 28. By day 17, there was intermittent eye opening, withdrawal to pain and some orofacial and limb movements. Further recovery had waxing and waning course. Now he is nearly 1 year post rabies encephalitis. He is unable to talk or comprehend, but can sit independently and is able to walk with support.ConclusionImmunosuppressive therapy with dexa to improve outcomes in rabies seems an exciting option. Optimal dose, time of start, and taper schedule need further studies. CSF ABT-based tapering appears promising. Larger studies with this approach are needed.Table 1Day13613172055Serum ABT2048X81923276816384163848192CSF ABT64X10248192X40964096Saliva PCRNegative (Neg)XNegXXXXCSF PCRNegXNegXXXXNuchal biospyxNegxXXXX Disclosures All authors: No reported disclosures.

Peri-electrode edema after deep brain stimulation

Peri-electrode edema can occur after deep brain stimulation (DBS). The diagnosis and management of peri-electrode edema may be challenging. We herein report non-infectious peri-electrode edema after the placement of DBS electrodes in patients with Parkinson’s disease (PD). Fifteen patients who underwent DBS surgery between 2010 and 2018 at Sapporo Medical University were included to identify post-operative peri-electrode edema. Pre- and post-operative CT and MRI were retrospectively analyzed.Six patients showed hyperintensity around the electrodes on FLAIR/T2 MRI without neurological deficits. Two patients showed limited FLAIR and DWI hyperintensities in deep white matter, and microvessels may have been occluded in these patients. In five patients, MRI revealed extensive FLAIR or T2 hyperintensity in surface white matter around the electrodes without vessel injury, whereas DWI showed no abnormal signals. The eosinophil count was increased in one of these five patients. Peri-electrode edema after DBS surgery is not an uncommon phenomenon, and includes two types: (1) limited edema in deep white matter and (2) extensive edema in surface white matter. Different mechanisms may be associated with these types of edemas.

The Central Vein: FLAIR Signal Abnormalities Associated with Developmental Venous Anomalies in Patients with Multiple Sclerosis.

Demyelination is a recently recognized cause of FLAIR hyperintensities associated with developmental venous anomalies. Our purpose was to quantify the prevalence of white matter signal abnormalities associated with developmental venous anomalies in patients with multiple sclerosis compared with controls. A retrospective, blinded, multireader study compared the prevalence of FLAIR hyperintense signal abnormalities adjacent to developmental venous anomalies in patients with MS compared with controls (patients with developmental venous anomalies without MS). Study findings were positive if a central vein was demonstrated using FLAIR and contrast-enhanced fat-saturated T1 sequences. Imaging parameters also included developmental venous anomaly location, developmental venous anomaly drainage, white matter lesion size, and depth of white matter lesions. Clinical parameters included age, sex, and the presence of confounding variables (hypertension, diabetes, migraines, and/or vasculopathy). FLAIR signal abnormality was present around 47.3% (35/74) of developmental venous anomalies in patients with MS, and 13.5% (10/74) of developmental venous anomalies in the control group (P < .001). The multivariate logistic regression model controlling for covariates (including migraines, hypertension, diabetes mellitus, vasculopathy, age, sex, and drainage direction of developmental venous anomalies) showed that the odds of FLAIR hyperintensity around developmental venous anomalies was 6.7-fold higher in patients with MS (relative risk MS = 6.68; 95% CI, 2.79-15.97; P < .001). The association of developmental venous anomalies and FLAIR hyperintensities was more common in patients with MS, which suggests that the underlying demyelinating pathologic process of MS may be the cause of this propensity in patients with MS. Impaired venous drainage in the territory of developmental venous anomalies may predispose to development of these lesions, and an associated central vein is helpful in understanding an atypical location of MS plaques.

THUR 038 Encephalopathy with MRI cortical ribbon and reversible white matter hyperintensities

We present an unusual case of encephalopathy with profound MR white matter and cortical abnormalities secondary to, and responsive to treatment for, hepatic encephalopathy alone.A 52-year-old man with known alcohol related liver disease (now abstinent), previous intravenous drug abuse and treated Hepatitis C presented over 18 months with discrete episodes of fluctuating confusion, and altered consciousness progressing to coma.Neuroimaging demonstrated symmetrical confluent white matter T2/ FLAIR hyperintensities in the posterior frontal and parietal lobes with symmetrical dWI cortical ribboning in the precentral gyrus. Due to his clinical state and the unusual neuroimaging findings he was transferred for further neurological investigation and management.On admission a serum ammonia was 111 µmol/L (normal range 16 – 60 µmol/L). Further to this a detailed systemic blood, imaging and CSF analysis did not yield an alternative diagnosis. Electroencephalography revealed generalised slowing.Serial imaging showed persistent, fluctuating, confluent, and symmetrical white matter T2/ FLAIR hyperintensities. Fluctuations in his clinical state correlated with serum ammonia levels, bowel motions, neuroimaging and the EEG findings. He was treated for hepatic encephalopathy alone, on one occasion in intensive care, with lactulose, phosphate enemas and diuretics. He was discharged home independently after a period of sustained clinical improvement.

Multimodal computational neocortical anatomy in pediatric hippocampal sclerosis.

ObjectiveIn contrast to adult cohorts, neocortical changes in epileptic children with hippocampal damage are not well characterized. Here, we mapped multimodal neocortical markers of epilepsy‐related structural compromise in a pediatric cohort of temporal lobe epilepsy and explored how they relate to clinical factors.MethodsWe measured cortical thickness, gray–white matter intensity contrast and intracortical FLAIR intensity in 22 patients with hippocampal sclerosis (HS) and 30 controls. Surface‐based linear models assessed between‐group differences in morphological and MR signal intensity markers. Structural integrity of the hippocampus was measured by quantifying atrophy and FLAIR patterns. Linear models were used to evaluate the relationships between hippocampal and neocortical MRI markers and clinical factors.ResultsIn the hippocampus, patients demonstrated ipsilateral atrophy and bilateral FLAIR hyperintensity. In the neocortex, patients showed FLAIR signal hyperintensities and gray–white matter boundary blurring in the ipsilesional mesial and lateral temporal neocortex. In contrast, cortical thinning was minimal and restricted to a small area of the ipsilesional temporal pole. Furthermore, patients with a history of febrile convulsions demonstrated more pronounced FLAIR hyperintensity in the ipsilesional temporal neocortex.InterpretationPediatric HS patients do not yet demonstrate the widespread cortical thinning present in adult cohorts, which may reflect consequences of a protracted disease process. However, pronounced temporal neocortical FLAIR hyperintensity and blurring of the gray–white matter boundary are already detectable, suggesting that alterations in MR signal intensities may reflect a different underlying pathophysiology that is detectable earlier in the disease and more pervasive in patients with a history of febrile convulsions.

Significance of hyperintense arteries on Gd-enhanced 3D T1W black-blood imaging in acute stroke.

To elucidate the pathogenesis of hyperintense arteries on Gd-enhanced 3D T1W BB FSE and their clinical significance in acute middle cerebral artery (MCA) stroke. We retrospectively reviewed 20 patients with MCA infarction. We measured the contrast-to-noise ratio between hyperintense artery and adjacent grey matter on T2-FLAIR and Gd-enhanced 3D T1W BB FSE and compared them by using Student's t test. The agreement of positive hyperintense artery between T2 FLAIR and Gd-enhanced 3D T1WI BB FSE was estimated with intraclass correlation coefficient. Our cohort was dichotomised into two groups depending on hyperintense artery scores, and clinical data were compared between two groups by using Student's t test and chi-square test. The contrast between hyperintense artery and grey matter on Gd-enhanced 3D T1W BB FSE was significantly higher than that on T2-FLAIR (2.27 ± 1.65 versus 0.94 ± 0.86, p = 0.01). Overall, agreement of hyperintense arteries on T2-FLAIR and Gd-enhanced 3D T1W BB FSE was excellent (ρ = 0.76, p < 0.01). Patients with higher hyperintense artery scores had higher perfusion deficits that those with lower hyperintense artery scores (196.7 ± 41.4 vs 100.1 ± 130.1, p = 0.03). Hyperintense arteries on Gd-enhanced 3D T1W BB FSE in acute MCA stroke may be associated with slow collateral flows. Their territories corresponded to those of FLAIR, but had a better contrast. The patients with hyperintense arteries in a wider territory showed larger perfusion deficit than those with hyperintense arteries in a narrower territory. • Hyperintense arteries on Gd-enhanced 3D T1W BB FSE are slow collateral flows. • Hyperintense arteries on Gd-enhanced 3D T1W BB FSE are well matched with FLAIR hyperintense vessels. • Hyperintense arteries are associated with perfusion deficit in stroke patients.

Differentiation of Cerebellar Hemisphere Tumors: Combining Apparent Diffusion Coefficient Histogram Analysis and Structural MRI Features

We aimed to develop a diagnostic algorithm for differentiation of cerebellar hemisphere tumors, combining Apparent Diffusion Coefficient (ADC) histogram analysis and structural imaging features. Pretreatment MRI of patients with pathologically proven cerebellar hemisphere neoplasms were reviewed. Voxel-wise volumetric ADC histograms of tumor solid components were determined. Histogram variables, patients' age, and structural imaging features were applied to develop a differential diagnosis algorithm. Among 142 patients, the most common tumors were metastasis (n = 54), hemangioblastoma (n = 39), pilocytic astrocytoma (n = 18), and medulloblastoma (n = 9). On ADC histogram analysis, medulloblastomas had the lowest, and pilocytic astrocytomas had the highest ADC values. An ADC 15th percentile value < 580 × 10-6 mm2 /s could differentiate medulloblastomas from other cerebellar hemisphere tumors with receiver operating characteristic (ROC) area under the curve (AUC) of .98 (P < .001). Comparing the two most common adult cerebellar hemisphere tumors (metastases and hemangioblastomas), hemangioblastomas had higher ADC values; and an ADC 90th percentile value > 2000 × 10-6 mm2 /s could identify hemangioblastomas with ROC AUC of .82 (P < .001). Along with ADC histogram and patients' age, structural imaging features including enhancement pattern, prominent vascular flow voids, surrounding FLAIR hyperintensity, and solid component T2 signal hyperintensity were independent differentiation variables in the diagnostic algorithm. In pretreatment differentiation of cerebellar tumors, the ADC histogram analysis is particularly helpful for distinction of medulloblastomas from other subtypes, and differentiation of the two most common adult tumors (ie, metastases and hemangioblastomas) from each other. Combination of structural imaging features and ADC histogram analysis can help with pretreatment differentiation of cerebellar tumors.

On differentiation between vasogenic edema and non-enhancing tumor in high-grade glioma patients using a support vector machine classifier based upon pre and post-surgery MRI images

PurposeHigh grade gliomas (HGGs) are infiltrative in nature. Differentiation between vasogenic edema and non-contrast enhancing tumor is difficult as both appear hyperintense in T2-W/FLAIR images. Most studies involving differentiation between vasogenic edema and non-enhancing tumor consider radiologist-based tumor delineation as the ground truth. However, analysis by a radiologist can be subjective and there remain both inter- and intra-rater differences. The objective of the current study is to develop a methodology for differentiation between non-enhancing tumor and vasogenic edema in HGG patients based on T1 perfusion MRI parameters, using a ground truth which is independent of a radiologist’s manual delineation of the tumor. Material and MethodsThis study included 9 HGG patients with pre- and post-surgery MRI data and 9 metastasis patients with pre-surgery MRI data. MRI data included conventional T1-W, T2-W, and FLAIR images and DCE-MRI dynamic images. In this study, the authors hypothesize that surgeried non-enhancing FLAIR hyperintense tissue, which was obtained using pre- and post-surgery MRI images of glioma patients, should be largely comprised of non-enhancing tumor. Hence this could be used as an alternative ground truth for the non-enhancing tumor region. Histological examination of the resected tissue was done for validation. Vasogenic edema was obtained from the non-enhancing FLAIR hyperintense region of metastasis patients, as they have a clear boundary between enhancing tumor and edema. DCE-MRI data analysis was performed to obtain T1 perfusion MRI parameters. Support Vector Machine (SVM) classification was performed using T1 perfusion MRI parameters to differentiate between non-enhancing tumor and vasogenic edema. Receiver-operating-characteristic (ROC) analysis was done on the results of the SVM classifier. For improved classification accuracy, the SVM output was post-processed via neighborhood smoothing. ResultsHistology results showed that resected tissue consists largely of tumorous tissue with 7.21 ± 4.05% edema and a small amount of healthy tissue. SVM-based classification provided a misclassification error of 8.4% in differentiation between non-enhancing tumor and vasogenic edema, which was further reduced to 2.4% using neighborhood smoothing. ConclusionThe current study proposes a semiautomatic method for segmentation between non-enhancing tumor and vasogenic edema in HGG patients, based on an SVM classifier trained on an alternative ground truth to a radiologist’s manual delineation of a tumor. The proposed methodology may prove to be a useful tool for pre- and post-operative evaluation of glioma patients.