ASPECTS estimation using dual-energy CTA-derived virtual non-contrast in large vessel occlusion acute ischemic stroke: a dose reduction opportunity for patients undergoing repeat CT?

PURPOSE: Recent studies have shown the feasibility of dual-energy CT (DECT) virtual non-contrast (VNC) for determining infarct extent. In this study, patients presenting with large-vessel occlusion (LVO) acute ischemic stroke (AIS), we assess whether ASPECTS on DECTA-VNC differs from non-contrast CT (NCCT). METHODS: After IRB approval, LVO-AIS patients undergoing NCCT and DECTA between October 2016 and September 2018 were retrospectively reviewed. DECTA-VNC images were derived using Syngo.via (Siemens, Erlangen, Germany). ASPECTS was scored by two blinded neuroradiologists. Square-weighted kappa statistic, diagnostic performance, Wilcoxon signed-rank tests between groups, and CT doses were calculated. RESULTS: Fifty-one patients met inclusion criteria, with median age of 76 (IQR 67-82); 26/51 (51%) were female. Median time between last-known-well and CT was 120 min (IQR 60-252). DECTA-VNC ASPECTS score differed by ≤ 1 from consensus NCCT in 49/51 (96%) patients for reader 1 and in 46/51 (90%) for reader 2. ASPECTS on DECTA-SI and consensus NCCT differed by ≤ 1 in 45/51 (88%) for both readers. On a per ASPECTS-region basis, DECTA-VNC had 87% sensitivity, 95% specificity, 0.82% PPV, and 0.96% NPV. ASPECTS inter-rater agreement was highest for DECTA-VNC (κ = 0.71), DECTA-SI (κ = 0.48), and NCCT (κ = 0.40). NCCT median CTDIvol was 63.7 mGy (IQR 60.7-67.2); DLP was 1060.0 mGy·cm (IQR 981.0-1151.5). DECTA-VNC dose was lower: median CTDIvol was 20.9 mGy (IQR 19.8-22.2); DLP was 804.1 (IQR 691.6-869.4), p < 0.0001. CONCLUSION: DECTA-derived VNC yielded similar ASPECTS scores as NCCT and is therefore non-inferior in early ischemia-related low attenuation edema/infarct detection in acute LVO-AIS patients. Further evaluation of the role of DECTA-VNC in AIS imaging is warranted.

Efficacy and safety of nerinetide for the treatment of acute ischaemic stroke (ESCAPE-NA1): a multicentre, double-blind, randomised controlled trial.

BACKGROUND: Nerinetide, an eicosapeptide that interferes with post-synaptic density protein 95, is a neuroprotectant that is effective in preclinical stroke models of ischaemia-reperfusion. In this trial, we assessed the efficacy and safety of nerinetide in human ischaemia-reperfusion that occurs with rapid endovascular thrombectomy in patients who had an acute ischaemic stroke. METHODS: For this multicentre, double-blind, randomised, placebo-controlled study done in 48 acute care hospitals in eight countries, we enrolled patients with acute ischaemic stroke due to large vessel occlusion within a 12 h treatment window. Eligible patients were aged 18 years or older with a disabling ischaemic stroke at the time of randomisation, had been functioning independently in the community before the stroke, had an Alberta Stroke Program Early CT Score (ASPECTS) greater than 4, and vascular imaging showing moderate-to-good collateral filling, as determined by multiphase CT angiography. Patients were randomly assigned (1:1) to receive intravenous nerinetide in a single dose of 2·6 mg/kg, up to a maximum dose of 270 mg, on the basis of estimated or actual weight (if known) or saline placebo by use of a real-time, dynamic, internet-based, stratified randomised minimisation procedure. Patients were stratified by intravenous alteplase treatment and declared endovascular device choice. All trial personnel and patients were masked to sequence and treatment allocation. All patients underwent endovascular thrombectomy and received alteplase in usual care when indicated. The primary outcome was a favourable functional outcome 90 days after randomisation, defined as a modified Rankin Scale (mRS) score of 0-2. Secondary outcomes were measures of neurological disability, functional independence in activities of daily living, excellent functional outcome (mRS 0-1), and mortality. The analysis was done in the intention-to-treat population and adjusted for age, sex, baseline National Institutes of Health Stroke Scale score, ASPECTS, occlusion location, site, alteplase use, and declared first device. The safety population included all patients who received any amount of study drug. This trial is registered with ClinicalTrials.gov, NCT02930018. FINDINGS: Between March 1, 2017, and Aug 12, 2019, 1105 patients were randomly assigned to receive nerinetide (n=549) or placebo (n=556). 337 (61·4%) of 549 patients with nerinetide and 329 (59·2%) of 556 with placebo achieved an mRS score of 0-2 at 90 days (adjusted risk ratio 1·04, 95% CI 0·96-1·14; p=0·35). Secondary outcomes were similar between groups. We observed evidence of treatment effect modification resulting in inhibition of treatment effect in patients receiving alteplase. Serious adverse events occurred equally between groups. INTERPRETATION: Nerinetide did not improve the proportion of patients achieving good clinical outcomes after endovascular thrombectomy compared with patients receiving placebo. FUNDING: Canadian Institutes for Health Research, Alberta Innovates, and NoNO.

A Detailed Analysis of Infarct Patterns and Volumes at 24-hour Noncontrast CT and Diffusion-weighted MRI in Acute Ischemic Stroke Due to Large Vessel Occlusion: Results from the ESCAPE-NA1 Trial.

Background The effect of infarct pattern on functional outcome in acute ischemic stroke is incompletely understood. Purpose To investigate the association of qualitative and quantitative infarct variables at 24-hour follow-up noncontrast CT and diffusion-weighted MRI with 90-day clinical outcome. Materials and Methods The Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke, or ESCAPE-NA1, randomized controlled trial enrolled patients with large-vessel-occlusion stroke undergoing mechanical thrombectomy from March 1, 2017, to August 12, 2019. In this post hoc analysis of the trial, qualitative infarct variables (predominantly gray [vs gray and white] matter involvement, corticospinal tract involvement, infarct structure [scattered vs territorial]) and total infarct volume were assessed at 24-hour follow-up noncontrast CT or diffusion-weighted MRI. White and gray matter infarct volumes were assessed in patients by using follow-up diffusion-weighted MRI. Infarct variables were compared between patients with and those without good outcome, defined as a modified Rankin Scale score of 0-2 at 90 days. The association of infarct variables with good outcome was determined with use of multivariable logistic regression. Separate regression models were used to report effect size estimates with adjustment for total infarct volume. Results Qualitative infarct variables were assessed in 1026 patients (mean age ± standard deviation, 69 years ± 13; 522 men) and quantitative infarct variables were assessed in a subgroup of 358 of 1026 patients (mean age, 67 years ± 13; 190 women). Patients with gray and white matter involvement (odds ratio [OR] after multivariable adjustment, 0.19; 95% CI: 0.14, 0.25; P < .001), corticospinal tract involvement (OR after multivariable adjustment, 0.06; 95% CI: 0.04, 0.10; P < .001), and territorial infarcts (OR after multivariable adjustment, 0.22; 95% CI: 0.14, 0.32; P < .001) were less likely to achieve good outcome, independent of total infarct volume. Conclusion Infarct confinement to the gray matter, corticospinal tract sparing, and scattered infarct structure at 24-hour noncontrast CT and diffusion-weighted MRI were highly predictive of good 90-day clinical outcome, independent of total infarct volume. Clinical trial registration no. NCT02930018 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mossa-Basha in this issue.

Whole-Exome Sequencing in NF1-Related West Syndrome Leads to the Identification of KCNC2 as a Novel Candidate Gene for Epilepsy.

Patients with neurofibromatosis type 1 (NF1) have an increased risk for West syndrome (WS), but the underlying mechanisms linking NF1 and WS are unknown. In contrast to other neurocutaneous syndromes, intracerebral abnormalities explaining the course of infantile spasms (IS) are often absent and the seizure outcome is usually favorable. Several studies have investigated a potential genotype-phenotype correlation between NF1 and seizure susceptibility, but an association was not identified. Therefore, we identified three patients with NF1-related WS (NF1-WS) in a cohort of 51 NF1 patients and performed whole-exome sequencing (WES) to identify genetic modifiers. In two NF1 patients with WS and good seizure outcome, we did not identify variants in epilepsy-related genes. However, in a single patient with NF1-WS and transition to drug-resistant epilepsy, we identified a de novo variant in KCNC2 (c.G499T, p.D167Y) coding for Kv3.2 as a previously undescribed potassium channel to be correlated to epilepsy. Electrophysiological studies of the identified KCNC2 variant demonstrated both a strong loss-of-function effect for the current amplitude and a gain-of-function effect for the channel activation recommending a complex network effect. These results suggest that systematic genetic analysis for potentially secondary genetic etiologies in NF1 patients and severe epilepsy presentations should be done.

Progressive neurologic dysfunction in a psoriasis patient treated with dimethyl fumarate.

Progressive multifocal leukoencephalopathy (PML) has recently been described in psoriasis or multiple sclerosis patients treated with fumaric acid esters (fumarates), who had developed severe and long-standing lymphocytopenia (<500/mm(3) ). We report a psoriasis patient who presented with progressive neurologic dysfunction and seizures after 2.5 years of fumarate therapy. Despite absolute lymphocyte counts remaining between 500-1000/mm(3) , his CD4(+) and CD8(+) T-cell counts were markedly low. MRI showed right hemispheric and brainstem lesions and JC virus DNA was undetectable in his cerebrospinal fluid. Brain biopsy revealed typical features of PML as well as JC virus-infected neurons. Clinicians should consider PML in the differential diagnosis of fumarate-treated patients presenting with brain lesions or seizures even in the absence of severe lymphocytopenia.

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness.

Autobiographical memories in our lives are critically dependent on temporal lobe structures. However, the contribution of CA1 neurons in the human hippocampus to the retrieval of episodic autobiographical memory remains elusive. In patients with a rare acute transient global amnesia, highly focal lesions confined to the CA1 field of the hippocampus can be detected on MRI. We studied the effect of these lesions on autobiographical memory using a detailed autobiographical interview including the remember/know procedure. In 14 of 16 patients, focal lesions in the CA1 sector of the hippocampal cornu ammonis were detected. Autobiographical memory was significantly affected over all time periods, including memory for remote periods. Impairment of episodic memory and autonoetic consciousness exhibited a strong temporal gradient extending 30 to 40 y into the past. These results highlight the distinct and critical role of human hippocampal CA1 neurons in autobiographical memory retrieval and for re-experiencing detailed episodic memories.

Practical uses of the BENCHMARK™ BMX®81 in the road less travelled: Guide catheter comparison for radial access in neurovascular intervention.

BACKGROUND: Radial arterial access has gained interest for neurovascular procedures in recent years. Although there are no randomized control trials for neurointervention procedures using radial access, there is growing literature demonstrating its feasibility and favorable outcomes. Equipment technical improvements, like the recently introduced BENCHMARK™ BMX®81 System, have made radial navigation safer, with improved maneuverability and support for a variety of procedures. We present a multicenter case series highlighting our institutional radial access experience comparing the BMX®81 with alternative catheters. METHODS: Multicenter retrospective cohort study of 80 patients who underwent neurovascular procedures through a radial approach. In half of the cases a BENCHMARK™ BMX®81 System was used. The comparison group consisted of the BENCHMARK™071 and 96, Neuron MAX®088 and BALLAST™ systems. Procedures included endovascular thrombectomy, carotid and brachiocephalic artery stenting, middle meningeal artery embolization, flow diverter stenting, vertebral artery sacrifice, aneurysm coiling, and WEB™ device deployment. RESULTS: In our series, the BMX®81 was successful in the navigation of the anatomy to the target location in 95% of cases. No radial access or BMX®81 related complications were identified. There was no significant difference in fluoroscopy time between the BMX81 and the comparison group. Four patients in the comparison group had catheter-related complications due to vasospasm. Eighty-six percent of BMX®81 cases had satisfactory outcomes and no technical difficulties. The remainder presented technical difficulties, but none of these were considered secondary to the puncture site or support structure. CONCLUSIONS: The BENCHMARK™ BMX®81 System is a recently developed guiding catheter which has design and size features supporting radial access for a variety of neurovascular interventions. Early multicenter experience highlights the ease of use and versatility of this new catheter as an alternative to transfemoral access as well as other catheters used for radial access.

Febrile infection-related epilepsy syndrome without detectable autoantibodies and response to immunotherapy: a case series and discussion of epileptogenesis in FIRES.

Febrile infection-related epilepsy syndrome (FIRES) is a severe postinfectious epileptic encephalopathy in previously healthy children and has three phases: the initial phase with a simple febrile infection, a few days later the acute phase characterized by a peracute onset of highly recurrent seizures or refractory status epilepticus often with no more fever and generally without additional neurological features (the classical pure seizure phenotype), and last, the chronic phase with a drug-resistant epilepsy and neuropsychological impairments. FIRES seems to be sporadic and very rare: we estimated the annual incidence in children and adolescents by a prospective hospital-based German-wide surveillance as 1 in 1,000,000. Because of the preceding infection and lacking evidence of infectious encephalitis, an immune-mediated pathomechanism and, therefore, a response to immunotherapies may be involved. To test the hypothesis that antibodies against neuronal structures cause FIRES, we analyzed sera of 12 patients aged 2 to 12 years (median 6 years) and cerebral spinal fluids (CSFs) of 3 of these 12 patients with acute or chronic FIRES. We studied six patients (two including CSF) 1 to 14 weeks (median 3 weeks) and six patients 1 to 6 years (median 3.5 years) after seizure onset. All samples were analyzed for antibodies against glutamate receptors of type N-methyl-D-aspartate (NMDA) and type α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA), gamma-aminobutyric acid (GABA)B-receptors, voltage-gated potassium channel (VGKC)-associated proteins leucin-rich glioma inactivated 1 (LGI1) and contactin-associated protein like 2 (CASPR2), and glutamic acid decarboxylase (GAD) by a multiparametric recombinant immunofluorescence assay employing human embryonic kidney (HEK) cells transfected with cDNAs for the antigens. In addition, indirect immunohistochemistry using rat whole-brain sections was done in three patients. Finally, sera of 10 patients were tested for VGKC complex antibodies by radioimmunoprecipitation assay (RIA). None of the antibody tests were positive in any of the patients. Moreover, steroids, immunoglobulins, and plasmapheresis had no clear effect in the seven patients receiving immunotherapy. The failure of antibody-detection against the known neuronal antigens as well as the ineffectiveness of immunotherapy questions a role for autoantibodies in the epileptogenesis of classical FIRES. As we discuss, other underlying causes need to be considered including the possibility of a mitochondrial encephalopathy.

The entire dural sinus tree is compressed in patients with idiopathic intracranial hypertension: a longitudinal, volumetric magnetic resonance imaging study.

INTRODUCTION: The objective of this study was to explore the volumetric alterations of dural sinuses in patients with idiopathic intracranial hypertension (IIH). METHODS: Standardized cranial magnetic resonance imaging (MRI) was used in 17 patients prior to and following treatment of IIH and in seven controls. Magnetic resonance venographies (MRV) were employed for (a) judgement of circumscript dural sinus stenoses and (b) computation of sinus volumes. Cross-sectional areas (CSA) of the superior sagittal sinuses (SSS) were measured on T2-weighted images. Results of the initial MRIs were compared to those on follow-up MRIs and to results of controls. RESULTS: Stenoses of the transverse sinuses (TS) resulting in cranial venous outflow obstruction (CVOO) were present in 15/17 (88%) patients, normalizing in 7/15 cases (47%) after treatment of IIH. CVOO was not detected in the control group. Segmentation of MRV revealed decreased dural sinus volumes in patients with IIH as compared to controls (P = 0.018). Sinus volumes increased significantly with normalization of intracranial pressure independent from disappearing of TS stenoses (P = 0.007). The CSA of the SSS were normal on the initial MRIs of patients with IIH and increased on follow-up after treatment (P < 0.001). However, volumetries displayed overlap in patients and controls. CONCLUSIONS: Patients with IIH not only exhibit bilateral stenoses of the TS as has been reported, but volume changes of their entire dural sinus system also occur. The potential etiopathological and diagnostic roles of these changes are discussed.

Assessment of thrombus in acute middle cerebral artery occlusion using thin-slice nonenhanced Computed Tomography reconstructions.

BACKGROUND AND PURPOSE: We sought to evaluate how accurately length and volume of thrombotic clots occluding cerebral arteries of patients with acute ischemic stroke can be assessed from nonenhanced CT (NECT) scans reconstructed with different slice widths. METHODS: NECT image data of 58 patients with acute ischemic stroke with vascular occlusion proven by CT angiography were reconstructed with slice widths of 1.25 mm, 2.5 mm, 3.75 mm, and 5 mm. Thrombus lengths and volumes were quantified based on these NECT images by detecting and segmenting intra-arterial hyperdensities. The results were compared with reference values of thrombus length and volume obtained from CT angiography images using Bland-Altman analysis and predefined levels or tolerance to find NECT slice thicknesses that allow for sufficiently accurate thrombus quantification. RESULTS: Thrombus length can be measured with high accuracy using the hyperdense middle cerebral artery sign detected in NECT images with slice thicknesses of 1.25 mm and 2.5 mm. We found mean deviations from the reference values and limits of agreement of -0.1 mm+/-0.6 mm with slice widths of 1.25 mm and 0.1 mm+/-0.7 mm for slice widths of 2.5 mm. Thrombus length measurements in NECT images with higher slice width and all evaluated thrombus volume measurements exhibited severe dependence on the level and did not match the accuracy criteria. CONCLUSIONS: The length of the hyperdense middle cerebral artery sign as detected on thin-slice NECT reconstructions in patients with acute ischemic stroke can be used to quantify thrombotic burden accurately. Thus, it might qualify as a new diagnostic parameter in acute stroke management that indicates and quantifies the extent of vascular obliteration.

Camptocormia in idiopathic Parkinson's disease: a focal myopathy of the paravertebral muscles.

The objective of our study was to describe the clinical features of camptocormia, an involuntary, marked flexion of the thoracolumbar spine in idiopathic Parkinson's disease (PD) and to understand its etiology. In a prospective, cross-sectional study, we examined 15 patients with PD and camptocormia using laboratory parameters, EMG, muscle magnetic resonance imaging, and biopsy of the paravertebral muscles. The clinical data were compared with a matched control group of PD patients without camptocormia, and the biopsies were compared with muscles from age-matched autopsies. Almost all the patients (median age, 68.0 years; 7 women) with camptocormia suffered from advanced PD. Camptocormia occurred at a median of 9.0 years after the PD diagnosis. Compared with our clinical control group, back pain was more frequent and less dopa-sensitive in the patients with camptocormia who suffered more often from additional diseases of the back. On EMG, we found mainly a myopathic pattern. The MRI of the paravertebral muscles showed localized changes ranging from edema with contrast enhancement, which are considered to be early signs, to atrophy and/or fatty degeneration, interpreted as late degenerative changes. Early signs were seen mainly during the first year and degenerative changes after 1.5 years. Biopsies revealed consistently myopathic changes and in some cases fatty degeneration. Clinical or electromyographic features favoring dystonia were absent. Camptocormia is a major disabling, non-fluctuating and levodopa-resistant complication of advanced PD. The cause of camptocormia in idiopathic PD is a focal myopathy. Our findings suggest that the myopathy has a progressive course, which finally leads to degeneration of the paravertebral muscles.

Febrile infection-related epilepsy syndrome (FIRES): a nonencephalitic encephalopathy in childhood.

Encephalitis is generally presumed, even when seizures follow banal febrile infection, and pathogen detection in cerebrospinal fluid fails. This retrospective multicenter case series reports on 22 previously healthy children aged 3-15 years (median 6.5 years) with prolonged or recurrent seizures occurring 2-14 days (median 5 days) after fever onset (19 children with respiratory or nonspecific infections). Cerebrospinal fluid studies revealed 2-42 cells/microl (median 5 cells/microl) and no pathogens. Electroencephalography showed diffuse slowing or multifocal discharges. Neuroimaging demonstrated normal findings in 10 children. Brain biopsies were performed in seven children showing gliosis but no inflammation. Anesthetic barbiturates were used in 14 children with refractory status epilepticus, and immunotherapy in 9. Two children died, eight remained in a state of impaired consciousness, eight developed therapy-refractory epilepsies, two had behavioral disturbances, and two recovered. The lack of evidence for encephalitis suggests another infection-related pathogenesis of this disastrous epileptic encephalopathy. Therefore, we propose the term "febrile infection-related epilepsy syndrome" (FIRES).

Complication rate in unprotected carotid artery stenting with closed-cell stents.

INTRODUCTION: The discussion on the use of protection devices (PDs) in carotid artery stenting (CAS) is gaining an increasing role in lowering the periprocedural complication rates. While many reviews and reports with retrospective data analysis do promote the use of PDs the most recent multi-centre trials are showing advantages for unprotected CAS combined with closed-cell stent designs. METHODS: We retrospectively analysed 358 unprotected CAS procedures performed from January 2003 to June 2009 in our clinic. Male/female ratio was 2.68/1. The average age was 69.3 years. Seventy-three percent (261/358) showed initial neurological symptoms. All patients were treated on a standardised interventional protocol. A closed and small-sized cell designed stent was implanted in most cases (85.2%). One hundred seventy-one (47.8%) were controlled by Doppler ultrasonography usually at first in a 3-month and later in 6-month intervals. RESULTS: The peri-interventional and 30-day mortality/stroke rate was 4.19% (15/358). These events included three deaths, five hyperperfusion syndromes (comprising one death by a secondary fatal intracranial haemorrhage), one subarachnoid haemorrhage and seven ischaemic strokes. Only 20% (3/15) of all complications occurred directly peri-interventional. The overall peri-interventional complication rate was 0.8% (3/358). Most complications occurred in initial symptomatic patients (5.36%). The in-stent restenosis rate for more than 70% was 7% (12/171) detected at an average of 9.8 month. CONCLUSION: Our clinical outcome demonstrates that unprotected CAS with small cell designed stents results in a very low procedural complication rate, which makes the use of a protection device dispensable.

Neurosarcoidosis presenting with hypopituitarism.

Hypothalamo-pituitary sarcoidosis is a rare manifestation of sarcoidosis, usually presenting alongside other symptoms of neurosarcoidosis. We describe the case of a 58-year-old man from Ghana who presented with progressive gait disturbance, cognitive dysfunction, hypothermia and bradycardia. He was found to have pituitary stalk thickening on imaging, and lymph node biopsy identified non-caseating granulomatous disease. Serology revealed gonadotropin deficiency, hypothyroidism and central adrenal insufficiency. Treatment with immunomodulatory therapy resulted in resolution of findings on imaging and improved cognition, though pituitary function never recovered. Treatment for his sarcoidosis unfortunately resulted in recurrent infections and avascular necrosis. Work-up, management and ongoing care required multidisciplinary cooperation between the admitting internal medicine team, infectious diseases, respirology, rheumatology, endocrinology and neurology.

Gliosarcoma: clinical experiences and additional information with MR spectroscopy.

Gliosarcomas represent about 2% of glioblastoma multiforme (WHO grade IV). They have mixed features of glial and sarcomatous components. The clinical presentation and prognosis are similar to glioblastoma. Between 1997 and 2006, 16 patients with intracranial gliosarcoma were treated in the Department of Neurosurgery in Kiel, Germany. Median age was 63 years (52-79 years). Eleven patients were men and five were women. Six tumors were in the frontal lobe, four in the temporal lobe, three parietal, two in the thalamic area and one in the occipital lobe. Pre-operatively, in two patients, we could perform magnetic resonance (MR) spectroscopy. There was lactate peak, which is a sign of local necrosis and hypoxia. Median survival time in our patient group was 7 months (2-11 months). On histological examination, we found glial fibrillary acid protein positive cells surrounded by sarcomatous tissue and reticular fibers. The proliferation index MIB-1 was between 20 and 70%. The prognosis in this patient group is still poor. MR spectroscopy and location of the tumor adjacent to the dura with inhomogeneous contrast enhancement might give hints pre-operatively for the differential diagnosis of gliosarcoma. Further works with adjuvant chemotherapy are necessary.

Association of right-to-left shunt with frontal white matter lesions in T2-weighted MR imaging of stroke patients.

INTRODUCTION: Cardiac right-to-left shunt (RLS), mainly due to patent foramen ovale (PFO), is a risk factor for paradoxical embolism and stroke. Results of studies about brain lesions in diffusion-weighted imaging (DWI) in PFO patients were controversial. DWI only detects acute ischemic lesions. We assessed the hypothesis that, in T2-weighted magnetic resonance imaging (T2WI) of stroke patients, RLS is associated with a typical distribution of small white matter lesions. MATERIALS AND METHODS: In this retrospective case-control study, T2WI images of 162 stroke patients were evaluated. From stroke patients admitted between 1999 and 2003, 81 stroke patients with RLS were identified with contrast-enhanced transcranial Doppler (bubble test). Controls were 81 age-matched stroke patients without RLS (negative bubble test). In T2WI images, small lesions (<2 cm) were categorized depending on their location in subcortical white matter, peritrigonal white matter, deep and paraventricular white matter, and basal ganglia. Additionally, larger territorial infarcts were rated. RESULTS: In T2WI frontal or predominantly frontal-located subcortical small white matter, lesions are significantly associated with RLS (p < 0.0001, chi-square test). Forty-three patients with RLS (53%) and only 19 control patients (23%) showed this frontal dominance. Odds ratio is 3.7 (95% confidence interval = 1.9-7.1) for having a RLS when T2WI shows this lesion pattern in a stroke patient. No patient of the RLS group and 6% of the control group had parietal dominance. Distribution of small lesions in other locations like basal ganglia or deep white matter showed no significant difference for the groups. CONCLUSION: A distribution of mainly frontal subcortical small white matter lesions in T2WI is significantly associated with RLS in stroke patients.

Dynamic contrast-enhanced susceptibility-weighted perfusion MRI (DSC-MRI) in a glioma model of the rat brain using a conventional receive-only surface coil with a inner diameter of 47 mm at a clinical 1.5 T scanner.

Magnetic resonance (MR) imaging in animal models is usually performed in expensive dedicated small bore animal scanners of limited availability. In the present study a standard clinical 1.5 T MR scanner was used for morphometric and dynamic contrast-enhanced susceptibility-weighted MR imaging (DSC-MRI) of a glioma model of the rat brain. Ten male Wistar rats were examined with coronal T2-weighted, and T1-weighted images (matrix 128 x 128, FOV 64 mm) after implantation of an intracerebral tumor xenografts (C6) using a conventional surface coil. For DSC-MRI a T2*-weighted sequence (TR/TE=30/14 ms, matrix 64 x 64, FOV 90 mm; slice thickness of 1.5mm) was performed. Regions of interest were defined within the tumor and the non-affected contralateral hemisphere and the mean transit time (MTT) was determined. Tumor dimensions in MR predicted well its real size as proven by histology. The MTT of contrast agent passing through the brain was significantly decelerated in the tumor compared to the unaffected hemisphere (p<0.001, paired t-test), which is most likely due to the leakage of contrast agent through the disrupted blood brain barrier. This setup offers advanced MR imaging of small animals without the need for dedicated animal scanners or dedicated custom-made coils.

Unenhanced Dual-Energy Computed Tomography: Visualization of Brain Edema.

PURPOSE: The aim of this study was to determine whether dual-energy computed tomography (DECT) imaging is superior to conventional noncontrast computed tomography (CT) imaging for the detection of acute ischemic stroke. MATERIALS AND METHODS: This was a retrospective, single-center study of 40 patients who presented to the emergency department (ED) of a major, acute care, teaching center with signs and symptoms of acute stroke. Only those patients who presented to the ED within 4 hours of symptom onset were included in this study. All 40 patients received a noncontrast DECT of the head at the time of presentation. Each patient also received standard noncontrast CT of the head 24 hours after their initial presentation to the ED. "Brain edema" images were then reconstructed using 3-material decomposition with parameters adjusted to suppress gray/white matter contrast while preserving edema and increasing its conspicuity. The initial unenhanced, mixed images, brain edema, and 24-hour follow-up true noncontrast (TNC) images were reviewed and assigned Alberta Stroke Program Early CT scores. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. RESULTS: Of the 40 patients, 28 (70%) were diagnosed with an acute infarction. Brain edema reconstructions were better able to predict end infarction volume, with Alberta Stroke Program Early CT scores similar to the 24-hour follow-up TNC CT (7.75 vs 7.7; P > 0.05), whereas the mixed images routinely underestimated the extent of infarction (8.975 vs 7.7; P < 0.001). Initial TNC images had a sensitivity, specificity, PPV, and NPV of 80% (95% confidence interval [CI], 51.9%-95.7%), 72.7% (95% CI, 39%-94%), 80% (95% CI, 51.9%-95.7%), and 72.73% (95% CI, 51.91%-95.67%), respectively. The DECT brain edema images provided a sensitivity, specificity, PPV, and NPV of 93.33% (95% CI, 68.05%-99.83%), 100% (95% CI, 71.51%-100%), 100% (95% CI, 76.84%-100%), and 91.67% (95% CI, 61.52%-99.79%), respectively. There was very good interrater reliability across all 3 imaging techniques. CONCLUSION: Brain edema reconstructions are able to more accurately detect edema and end-infarct volume as compared with initial TNC images. This provides a better assessment of the degree and extent of infarction and may serve to better guide therapy in the future.

De novo development of intraosseous cavernous hemangioma.

Intraosseous cavernous hemangiomas are rare and not often multifocal. De novo development of a skull cavernous hemangioma has not been described previously. We present a 20-year-old man who was operated upon for a skull cavernoma in the right frontal area and developed a new lesion 3 years later in the right occipital region. The first lesion was removed completely and the postoperative course was uneventful. Histology showed an intraosseous cavernous hemangioma. MRI follow-up revealed a new lesion in the right occipital region. At the time of the first operation this lesion was not seen on CT or MRI scan. Surgical removal was performed and histology again showed a cavernous hemangioma. The patient seems to be unique and it is important to keep young patients with the diagnosis of cavernous hemangioma under close follow-up. This supports the experience from parenchymatous cavernous hemangiomas that this malformation may become a dynamic disease.