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Copyright of Česká a Slovenská Neurologie a Neurochirurgie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Patients with a left (LHS) or right hemispheric stroke (RHS) differ in terms of clinical symptoms due to lateralization of specific cortical functions. Studies on functional outcome after stroke and endovascular thrombectomy (EVT) comparing both hemispheres showed conflicting results so far. The impact of stroke laterality on patient-reported health-related quality of life (HRQoL) after EVT has not yet been adequately addressed and still remains unclear. Methods: Consecutive stroke thrombectomy patients, derived from a multi-center, prospective registry (German Stroke Registry) between June 2015 and December 2019, were included in this study. At 90 days, outcome after EVT was assessed by the modified Rankin scale (mRS) and HRQoL using the European QoL-five dimensions questionnaire utility-index (EQ-5D-I; higher values indicate better HRQoL) in patients with LHS and RHS. Adjusted regression analysis was applied to evaluate the influence of stroke laterality on outcome after EVT. Results: In total, 5683 patients were analyzed. Of these, 2953 patients (52.8%) had LHS and 2637 (47.2%) RHS. LHS patients had a higher baseline NIHSS (16 vs. 13, p < 0.001) and a higher ASPECTS (9 vs. 8, p < 0.001) compared to RHS patients. Among survivors, patients with LHS less frequently had a self-reported affected mobility (p = 0.037), suffered less often from pain (p = 0.04) and anxiety/depression (p = 0.032) three months after EVT. After adjusting for confounders (age, sex, baseline NIHSS), LHS was associated with a better HRQoL (ß coefficient 0.04, CI 95% 0.017–0.063; p = 0.001), and better functional outcome assessed by lower values on the mRS (ß coefficient − 0.109, CI 95% − 0.217–0.000; p = 0.049). Conclusions: Ninety days after EVT, LHS patients have a better functional outcome and HRQoL. Patients with RHS should be actively assessed and treated for pain, anxiety and depression to improve their HRQoL after EVT. [ABSTRACT FROM AUTHOR]

Purpose: Grey matter (GM) atrophy due to neuronal loss is a striking feature of patients with CLN3 disease. A precise and quantitative description of disease progression is needed in order to establish an evaluation tool for current and future experimental treatments. In order to develop a quantitative marker to measure brain volume outcome, we analysed the longitudinal volumetric development of GM, white matter (WM) and lateral ventricles and correlated those with the clinical course. Methods: One hundred twenty-two MRI scans of 35 patients (21 females; 14 males; age 15.3 ± 4.8 years) with genetically confirmed CLN3 disease were performed. A three-dimensional T1-weighted sequence was acquired with whole brain coverage. Volumetric segmentation of the brain was performed with the FreeSurfer image analysis suite. The clinical severity was assessed by the Hamburg jNCL score, a disease-specific scoring system. Results: The volumes of supratentorial cortical GM and supratentorial WM, cerebellar GM, basal ganglia/thalamus and hippocampus significantly (r = − 0.86 to − 0.69, p < 0.0001) decreased with age, while the lateral ventricle volume increased (r = 0.68, p < 0.0001). Supratentorial WM volume correlated poorer with age (r = − 0.56, p = 0.0001). Supratentorial cortical GM volume showed the steepest (4.6% (± 0.2%)) and most uniform decrease with strongest correlation with age (r = − 0.86, p < 0.0001). In addition, a strong correlation with disease specific clinical scoring existed for the supratentorial cortical GM volume (r = 0.85, p = < 0.0001). Conclusion: Supratentorial cortical GM volume is a sensitive parameter for assessment of disease progression even in early and late disease stages and represents a potential reliable outcome measure for evaluation of experimental therapies. [ABSTRACT FROM AUTHOR]

Objective: Arterial spin labeling blood perfusion signal relies on the difference between a label and a control image. Background suppression pulses are commonly used to improve the contrast, yet these are based on estimates of tissue relaxation times. The aim of this study is to improve the perfusion contrast by individualizing the timing of these background suppression pulses by means of T1 mapping. Methods: The optimized timing of the background suppression pulses is obtained by rapid T1 mapping employing the variable flip angle technique. Ten healthy volunteers were included in this study. To compare the results, visual grading and the Wilcoxon signed-rank test was used comparing three categories of image quality. Results: The readers confirmed that the images of the proposed method generally show a higher signal-to-background ratio and cortical structures are better visible. Noise was mostly comparable to the standard method. Relative blood flow was statistically significant higher in the modified method. Conclusion: The individually optimized background suppression pulses improve the image appearance and allow for a better visualization of cortical structures. The proposed technique however prolongs scan time, which can be seen as negative result, yet needs to be further evaluated. Key Points: • Background suppression timing in ASL can vary. • Both the label and control condition can be modified for T1 mapping. • Adapting the pulse timing improves the signal-to-background ratio. [ABSTRACT FROM AUTHOR]

Purpose: In mechanical thrombectomy, it has been hypothesized that multiple retrieval attempts might the improve reperfusion rate but not the clinical outcome. In order to assess a potential harmful effect of a mechanical thrombectomy on patient outcome, the number of retrieval attempts was analyzed. Only patients with a thrombolysis in cerebral infarction (TICI) score of 0 were reviewed to exclude the impact of eventual successful reperfusion on the mechanical hazardousness of repeated retrievals. Methods: In this study 6635 patients who underwent endovascular thrombectomy (EVT) for acute large vessel occlusion (LVO) from the prospectively administered multicenter German Stroke Registry were screened. Insufficient reperfusion was defined as no reperfusion (TICI score of 0), whereas a primary outcome was defined as functional independence (modified Rankin scale [mRS] 0–2 at day 90). Propensity score matching and multivariable logistic regressions were then performed to adjust for confounders. Results: A total of 377 patients (7.8%) had a final TICI score of 0 and were included in the study. After propensity score matching functional independence was found to be significantly more frequent in patients who underwent ≤ 2 retrieval attempts (14%), compared to patients with > 2 retrieval attempts (3.9%, OR 0.29, 95% CI 0.07–0.73, p = 0.009). After adjusting for age, sex, admission NIHSS score, and location of occlusion, more than two retrieval attempts remained significantly associated with lower odds of functional independence at 90 days (OR 0.2, 95% CI 0.07–0.52, p = 0.002). Conclusion: In patients with failure of reperfusion, more than two retrieval attempts were associated with a worse clinical outcome, therefore indicating a possible harmful effect of multiple retrieval attempts. [ABSTRACT FROM AUTHOR]

Background and Purpose: A Thrombolysis in Cerebral Infarction (TICI) score of 3 has been established as therapeutic goal in endovascular therapy (EVT) for acute ischemic stroke; however, in the case of early TICI2b reperfusion, the question remains whether to stop the procedure or to continue in the pursuit of perfection (i.e., TICI 2c/3). Methods: A total of 6635 patients were screened from the German Stroke Registry. Patients who underwent EVT for occlusion of the middle cerebral artery (M1 segment), with final TICI score of 2b/3 were included. Multivariable logistic regression was performed with functional independence (modified Rankin Scale, mRS at day 90 of 0–2) as the dependent variable. Results: Of 1497 patients, 586 (39.1%) met inclusion criteria with a final TICI score of 2b and 911 (60.9%) with a TICI score of 3. Patients who achieved first-pass TICI3 showed highest odds of functional independence (Odds ratio [OR] 1.71, 95% confidence interval [95% CI] 1.18–2.47). Patients who achieved TICI2b with the second pass (OR 0.53, 95% CI 0.31–0.89) or with three or more passes (OR 0.44, 95% CI 0.27–0.70) had significantly worse clinical outcomes compared to first-pass TICI2b. TICI3 at the second pass was by trend better than first-pass TICI2b (OR 1.55, 95% CI 0.98–2.45), but TICI3 after 3 or more passes (OR 0.93, 95% CI 0.57–1.50) was not significantly different from first-pass TICI2b. Conclusion: First-pass TICI2b was superior to TICI2b after ≥ 2 retrievals and comparable to TICI3 at ≥ 3 retrievals. The potential benefit in outcome after achieving TICI3 following further retrieval attempts after first-pass TICI2b need to be weighed against the risks. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to analyze sex differences in outcome after thrombectomy for acute ischemic stroke in clinical practice in a large prospective multicenter registry. Methods: Data of consecutive stroke patients treated with thrombectomy (June 2015–April 2018) derived from an industry-independent registry (German Stroke Registry–Endovascular Treatment) were prospectively analyzed. Multivariable binary logistic regression analyses were applied to determine whether sex is a predictor of functional independence outcome (defined as a modified Rankin scale [mRS] 0–2) 90 days after stroke. Results: In total, 2316 patients were included in the analysis, 1170 (50.5%) were female and 1146 (49.5%) were male. Women were older (median age 78 vs. 72 years; p < 0.001) and more frequently had a prestroke functional impairment defined by mRS >1 (24.8% vs. 14.1%; p < 0.001). In unadjusted analyses, independent outcome at 90 days was less frequent in women (33.2%) than men (40.6%; p < 0.001). Likewise, mortality was higher in women than in men (30.7% vs. 26.4%; p = 0.024). In adjusted regression analyses, however, sex was not associated with outcome. Lower age, a lower baseline National Institutes of Health Stroke Scale score, a higher Alberta Stroke Program Early CT score, prestroke functional independence, successful reperfusion, and concomitant intravenous thrombolysis therapy predicted independent outcome. Conclusion: Women showed a worse functional outcome after thrombectomy for acute ischemic stroke in clinical practice; however, after adjustment for crucial confounders sex was not a predictor of outcome. The difference in outcome thus appears to result from differences in confounding factors such as age and prestroke functional status. [ABSTRACT FROM AUTHOR]

Copyright of Der Nervenarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and purpose: Polypharmacy is an important challenge in clinical practice. Our aim was to determine the effect of polypharmacy on functional outcome and treatment effect of alteplase in acute ischaemic stroke. Methods: This was a post hoc analysis of the randomized, placebo‐controlled WAKE‐UP trial of magnetic resonance imaging guided intravenous alteplase in unknown onset stroke. Polypharmacy was defined as an intake of five or more medications at baseline. Comorbidities were assessed by the Charlson Comorbidity Index (CCI). The primary efficacy variable was favourable outcome defined by a score of 0–1 on the modified Rankin Scale at 90 days. Logistic regression analysis was used to test for an association of polypharmacy with functional outcome, and for interaction of polypharmacy and the effect of thrombolysis. Results: Polypharmacy was present in 133/503 (26%) patients. Patients with polypharmacy were older (mean age 70 vs. 64 years; p < 0.0001) and had a higher score on the National Institutes of Health Stroke Scale at baseline (median 7 vs. 5; p = 0.0007). A comorbidity load defined by a CCI score ≥ 2 was more frequent in patients with polypharmacy (48% vs. 8%; p < 0.001). Polypharmacy was associated with lower odds of favourable outcome (adjusted odds ratio 0.50, 95% confidence interval 0.30–0.85; p = 0.0099), whilst the CCI score was not. Treatment with alteplase was associated with higher odds of favourable outcome in both groups, with no heterogeneity of treatment effect (test for interaction of treatment and polypharmacy, p = 0.29). Conclusion: In stroke patients, polypharmacy is associated with worse functional outcome after intravenous thrombolysis independent of comorbidities. However, polypharmacy does not interact with the beneficial effect of alteplase. [ABSTRACT FROM AUTHOR]

Background and purpose: It is currently unknown whether mechanical thrombectomy (MT) for ischaemic stroke patients with low initial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is clinically beneficial or even harmful. The purpose of this study was to investigate whether failed or incomplete MT in acute large vessel occlusion stroke with an initial ASPECTS ≤ 5 is associated with worse clinical outcome compared to patients not undergoing MT. Methods: This observational cohort study included a consecutive sample of patients with anterior circulation stroke and initial ASPECTS ≤ 5 admitted between March 2015 and August 2019. Failed recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) score 0–2a, and incomplete recanalization as TICI 2b. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days defining very poor clinical outcome as mRS > 4. Results: One hundred and seventy patients were included. Ninety‐nine patients underwent MT and 71 patients received best medical treatment only. Clinical outcome after failed or incomplete MT (TICI 0–2b) was significantly better compared to patients with medical treatment only (median mRS 5, interquartile range 4–6 vs 5–6, P = 0.03). In multivariable logistic regression analysis, failed or incomplete MT (TICI 0–2b) showed a significantly reduced likelihood for very poor outcome (odds ratio 0.39, 95% confidence interval 0.19–0.83, P = 0.01). Failed MT (TICI 0–2a) was not associated with a worse outcome compared to best medical treatment. Conclusions: Patients with failed or incomplete recanalization results (TICI 0–2b) showed a reduced likelihood for very poor outcome compared with those who did not receive MT. Evidence from randomized trials is needed to confirm that even failed or incomplete MT is not harmful in these patients. [ABSTRACT FROM AUTHOR]

Background: Treatment of individuals with asymptomatic carotid artery stenosis is still handled controversially. Recommendations for treatment of asymptomatic carotid stenosis with carotid endarterectomy (CEA) are based on trials having recruited patients more than 15 years ago. Registry data indicate that advances in best medical treatment (BMT) may lead to a markedly decreasing risk of stroke in asymptomatic carotid stenosis. The aim of the SPACE-2 trial (ISRCTN78592017) was to compare the stroke preventive effects of BMT alone with that of BMT in combination with CEA or carotid artery stenting (CAS), respectively, in patients with asymptomatic carotid artery stenosis of ≥70% European Carotid Surgery Trial (ECST) criteria. Methods: SPACE-2 is a randomized, controlled, multicenter, open study. A major secondary endpoint was the cumulative rate of any stroke (ischemic or hemorrhagic) or death from any cause within 30 days plus an ipsilateral ischemic stroke within one year of follow-up. Safety was assessed as the rate of any stroke and death from any cause within 30 days after CEA or CAS. Protocol changes had to be implemented. The results on the one-year period after treatment are reported. Findings: It was planned to enroll 3550 patients. Due to low recruitment, the enrollment of patients was stopped prematurely after randomization of 513 patients in 36 centers to CEA (n = 203), CAS (n = 197), or BMT (n = 113). The one-year rate of the major secondary endpoint did not significantly differ between groups (CEA 2.5%, CAS 3.0%, BMT 0.9%; p = 0.530) as well as rates of any stroke (CEA 3.9%, CAS 4.1%, BMT 0.9%; p = 0.256) and all-cause mortality (CEA 2.5%, CAS 1.0%, BMT 3.5%; p = 0.304). About half of all strokes occurred in the peri-interventional period. Higher albeit statistically non-significant rates of restenosis occurred in the stenting group (CEA 2.0% vs. CAS 5.6%; p = 0.068) without evidence of increased stroke rates. Interpretation: The low sample size of this prematurely stopped trial of 513 patients implies that its power is not sufficient to show that CEA or CAS is superior to a modern medical therapy (BMT) in the primary prevention of ischemic stroke in patients with an asymptomatic carotid stenosis up to one year after treatment. Also, no evidence for differences in safety between CAS and CEA during the first year after treatment could be derived. Follow-up will be performed up to five years. Data may be used for pooled analysis with ongoing trials. [ABSTRACT FROM AUTHOR]

Purpose: Prior reports on the location and sizes of brain metastases almost entirely focus on patients with primary breast and pulmonary cancer. This is the first study comparing multiple other types of cancer that metastasize to the brain. Methods: This monocentric retrospective study includes 369 untreated patients with 3313 intraaxial brain metastases. Following semi-manual segmentation of metastases on post-contrast T1WI, cumulative spatial probability distribution maps of brain metastases were created for the whole group and for all primary tumors. Furthermore, mixed effects logistic regression model analysis was performed to determine if the primary tumor, patient age, and patient sex influence lesion location. Results: The cerebellum as location of brain metastases was proportionally overrepresented. Breast and pulmonary cancer caused higher number of brain metastases to what would normally be expected. Multivariate analyses revealed a significant accumulation of brain metastases from skin cancer in a frontal and from breast and gastrointestinal cancer in a cerebellar location. Conclusion: Distribution of brain metastases is very heterogeneous for the distinct primaries, possibly reflecting the diversity of mechanisms involved in brain metastases formation. In daily clinical practice distribution patters may be beneficial to predict the primary cancer site, if unknown. [ABSTRACT FROM AUTHOR]

Background and purpose: Intravenous (IV) lysis with alteplase is known to increase biomarkers of blood–brain barrier breakdown and has therefore been associated with secondary injuries such as hemorrhagic transformation. The impact of alteplase on brain edema formation, however, has not been investigated yet. The purpose was to examine the effects of IV alteplase on ischaemic lesion water homeostasis differentiated from final tissue infarct in patients with and without successful endovascular therapy (sET). Methods: In all, 232 middle cerebral artery stroke patients were analyzed. 147 patients received IV alteplase, of whom 106 patients received subsequent sET. Out of 85 patients without IV alteplase, 50 received sET. Ischaemic brain edema was quantified at admission and follow‐up computed tomography using quantitative lesion net water uptake (NWU) and its difference was calculated (ΔNWU). The relationship of alteplase on ΔNWU and edema‐corrected final infarct volume was analyzed using univariate and multivariate linear regression models. Results: The mean ΔNWU was 11.8% (SD 7.9) in patients with alteplase and 11.5% (SD 8.3) in patients without alteplase (P = 0.8). Alteplase was not associated with lowered ΔNWU whilst being associated with reduced edema‐corrected tissue infarct volume [−27.4 ml, 95% confidence interval (CI) −49.4 to −5.4 ml; P = 0.02], adjusted for the Alberta Stroke Program Early Computed Tomography Score and recanalization status. In patients with sET, ΔNWU was 10.5% (95% CI 6.3%–10.5%) for patients with IV alteplase and 8.4% (95% CI 9.1%–12.0%) for patients without IV alteplase. Conclusion: The application of IV alteplase did not significantly alter ischaemic lesion water homeostasis but was associated with reduced edema‐corrected tissue infarct volume, which might be directly linked to improved functional outcome. [ABSTRACT FROM AUTHOR]

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To assess the diagnostic value of multiparametric magnetic resonance imaging (MRI) including dynamic Gd-EOB-DTPA-enhanced (DCE) and diffusion-weighted (DW) imaging for diagnosis and staging of hepatic fibrosis in primary sclerosing cholangitis (PSC) using transient elastography as a standard reference.Material and Methods: Multiparametric MRI was prospectively performed on a 3.0-Tesla scanner in 47 patients (age 43.9±14.3 years). Transient elastography derived liver stiffness measurements (LSM), DCE-MRI derived parameters (hepatocellular uptake rate (Ki), arterial (Fa), portal venous (Fv) and total (Ft) blood flow, mean transit time (MTT), and extracellular volume (Ve)) and the apparent diffusion coefficient (ADC) were calculated. Correlation and univariate analysis of variance with post hoc pairwise comparison were applied to test for differences between LSM derived fibrosis stages (F0/F1, F2/3, F4). ROC curve analysis was used as a performance measure.Results: Both ADC and Ki correlated significantly with LSM (r= -0.614; p<0.001 and r= -0.368; p=0.01). The ADC significantly discriminated fibrosis stages F0/1 from F2/3 and F4 (p<0.001). Discrimination of F0/1 from F2/3 and F4 reached a sensitivity/specificity of 0.917/0.821 and 0.8/0.929, respectively. Despite significant inter-subject effect for classification of fibrosis stages, post hoc pairwise comparison was not significant for Ki (p>0.096 for F0/1 from F2/3 and F4). LSM, ADC and Ki were significantly associated with serum-based liver functional tests, disease duration and spleen volume.Conclusion: DW-MRI provides a higher diagnostic performance for detection of hepatic fibrosis and cirrhosis in PSC patients in comparison to Gd-EOB-DTPA-enhanced DCE-MRI.Key Points: • Both ADC and hepatocellular uptake rate (Ki) correlate significantly with liver stiffness (r= -0.614; p<0.001 and r= -0.368; p=0.01). • The DCE-imaging derived quantitative parameter hepatocellular uptake rate (Ki) fails to discriminate pairwise intergroup differences of hepatic fibrosis (p>0.09). • DWI is preferable to DCE-imaging for discrimination of fibrosis stages F0/1 to F2/3 (p<0.001) and F4 (p<0.001). [ABSTRACT FROM AUTHOR]

In the last decade the number of stroke patients in the Russian Federation ranged from ca. 495,000 to 510,000 according to Rosstat (Russian Federal Statistics Service) rendering it the second leading cause of death in Russia. To familiarize these specialists with acute ischemic stroke treatment, St. Petersburg started hosting training sessions and master classes on ET in patients with acute CVA. Currently, 16 stroke centers are treating CVA patients in St. Petersburg. [Extracted from the article]

Purpose: Phase imaging provides additional information on multiple sclerosis (MS) lesions and may in combination with mean diffusivity (MD) and magnetization transfer ratio (MTR) help differentiating heterogeneity of MS lesion pathology. Methods: Magnetic resonance imaging (MRI) was performed in 23 MS patients including diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), and SWI. Mean values (MTR, MD, and homodyne filtered phase) from 138 chronic MS lesions and normal appearing white matter (NAWM) were obtained and correlations examined. For explorative analysis, a divisive hierarchical clustering algorithm was applied. Results: Phase characteristics were an independent characteristic of chronic T2 lesions, as MTR and MD were not correlated with phase values (R = − 0.23, R = − 0.18). Dependent on MTR, MD, and phase, cluster analysis led to five lesion groups. Of the two groups with phase values close to NAWM, one presented with highest MD and most severe MTR decrease ( p = 0.01), the other with slight MD increase and MTR decrease. Two lesion groups with highest phase values ( p = 0.01) displayed slightly increased MD and moderate decrease in MTR. Clinical data including EDSS, disease duration, and age did not differ significantly between groups. Conclusions: Increased phase is predominantly detectable in lesions with clear MTR decrease but only moderate MD increase. Phase images seem to represent an independent parameter for MS lesion characterization and may provide additional information on MS lesion heterogeneity. [ABSTRACT FROM AUTHOR]

Objectives: Exact cerebrovascular segmentations are required for several applications in today's clinical routine. A major drawback of typical automatic segmentation methods is the occurrence of gaps within the segmentation. These gaps are typically located at small vessel structures exhibiting low intensities. Manual correction is very time-consuming and not suitable in clinical practice. This work presents a post-processing method for the automatic detection and closing of gaps in cerebrovascular segmentations.Methods: In this approach, the 3D centerline is calculated from an available vessel segmentation, which enables the detection of corresponding vessel endpoints. These endpoints are then used to detect possible connections to other 3D centerline voxels with a graph-based approach. After consistency check, reasonable detected paths are expanded to the vessel boundaries using a level set approach and combined with the initial segmentation.Results: For evaluation purposes, 100 gaps were artificially inserted at non-branching vessels and bifurcations in manual cerebrovascular segmentations derived from ten Time-of-Flight magnetic resonance angiography datasets. The results show that the presented method is capable of detecting 82% of the non-branching vessel gaps and 84% of the bifurcation gaps. The level set segmentation expands the detected connections with 0.42 mm accuracy compared to the initial segmentations. A further evaluation based on 10 real automatic segmentations from the same datasets shows that the proposed method detects 35 additional connections in average per dataset, whereas 92.7% were rated as correct by a medical expert.Conclusion: The presented approach can considerably improve the accuracy of cerebrovascular segmentations and of following analysis outcomes. [ABSTRACT FROM AUTHOR]

Objectives: Cerebral vascular malformations might lead to strokes due to occurrence of ruptures. The rupture risk is highly related to the individual vascular anatomy. The 3D Time-of-Flight (TOF) MRA technique is a commonly used non-invasive imaging technique for exploration of the vascular anatomy. Several clinical applications require exact cerebrovascular segmentations from this image sequence. For this purpose, intensity-based segmentation approaches are widely used. Since small low-contrast vessels are often not detected, vesselness filter-based segmentation schemes have been proposed, which contrariwise have problems detecting malformed vessels. In this paper, a fuzzy logic-based method for fusion of intensity and vesselness information is presented, allowing an improved segmentation of malformed and small vessels at preservation of advantages of both approaches.Methods: After preprocessing of a TOF dataset, the corresponding vesselness image is computed. The role of the fuzzy logic is to voxel-wisely fuse the intensity information from the TOF dataset with the corresponding vesselness information based on an analytically designed rule base. The resulting fuzzy parameter image can then be used for improved cerebrovascular segmentation.Results: Six datasets, manually segmented by medical experts, were used for evaluation. Based on TOF, vesselness and fused fuzzy parameter images, the vessels of each patient were segmented using optimal thresholds computed by maximizing the agreement to manual segmentations using the Tanimoto coefficient. The results showed an overall improvement of 0.054 (fuzzy vs. TOF) and 0.079 (fuzzy vs. vesselness). Furthermore, the evaluation has shown that the method proposed yields better results than statistical Bayes classification.Conclusion: The proposed method can automatically fuse the benefits of intensity and vesselness information and can improve the results of following cerebrovascular segmentations. [ABSTRACT FROM AUTHOR]

Copyright of Der Nervenarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Nervenarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Neuroradiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stroke is one of the most frequent and most significant vascular diseases. According to estimates, 16.9 million people suffered a stroke in 2010, and over one-third of the incidents were lethal. The risk of suffering a stroke due to intracranial stenosis is between 7 and 24 %. As opposed to extracranial stenoses of the internal carotid artery, there is no standardized treatment concept for intracranial stenoses. At present, treatment with a low daily dose of 100 mg aspirin is recommended by the guidelines for intracranial stenoses to additionally prevent dose-dependent gastrointestinal side effects and bleeding complications. The WINGSPAN study showed stroke rates and mortality rates amounting to 4.5 % after 30 days and 7.0 % after 6 months. The Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis study is a randomized, multicenter study that compared endovascular stent treatment in patients with symptomatic arteriosclerotic intracranial stenoses with intensified drug therapy. After the inclusion of 451 of 764 study patients planned initially, study recruitment was terminated prematurely because the stroke rate or mortality rate within 30 days was 14.7 % in the endovascular treatment group compared with 5.8 % in the drug therapy group and 20 % within 12 months compared with 12.2 %. Quite recently the results of a second randomized study of intracranial stents were published in the Vitesse Intracranial Stent Study for Ischemic Stroke Therapy study. In an analysis published by Liebeskind et al. concerning the impact of collateral vessels on the stroke risk based on data from the Warfarin-Aspirin Symptomatic Intracranial Disease study, it was demonstrated that a sufficiently formed collateral network in patients with high-degree vascular constrictions (≥ 70 %) plays a crucial role in the avoidance of strokes. If there is no system of collateral vessels or if it is insufficient, the stroke risk in the dependent vascular territory is six times higher. So far it has not yet been possible to conclusively answer the question of optimal treatment for intracranial stenoses. There is particularly need for action regarding the treatment of high-degree recurrent symptomatic stenoses, not only in light of the unfavorable prognosis but also within the scope of demographic change. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this work is to present the software tool ANTONIA, which has been developed to facilitate a quantitative analysis of perfusion-weighted MRI (PWI) datasets in general as well as the subsequent multi-parametric analysis of additional datasets for the specific purpose of acute ischemic stroke patient dataset evaluation. Methods: Three different methods for the analysis of DSC or DCE PWI datasets are currently implemented in ANTONIA, which can be case-specifically selected based on the study protocol. These methods comprise a curve fitting method as well as a deconvolution-based and deconvolution-free method integrating a previously defined arterial input function. The perfusion analysis is extended for the purpose of acute ischemic stroke analysis by additional methods that enable an automatic atlas-based selection of the arterial input function, an analysis of the perfusion-diffusion and DWI-FLAIR mismatch as well as segmentation-based volumetric analyses. Results: For reliability evaluation, the described software tool was used by two observers for quantitative analysis of 15 datasets from acute ischemic stroke patients to extract the acute lesion core volume, FLAIR ratio, perfusion-diffusion mismatch volume with manually as well as automatically selected arterial input functions, and follow-up lesion volume. The results of this evaluation revealed that the described software tool leads to highly reproducible results for all parameters if the automatic arterial input function selection method is used. Conclusion: Due to the broad selection of processing methods that are available in the software tool, ANTONIA is especially helpful to support image-based perfusion and acute ischemic stroke research projects. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to investigate diagnostic sensitivity and reliability for the detection of middle cerebral artery occlusion (MCAO) on non-contrast-enhanced computed tomography (NECT) by visual assessment (VA), Hounsfield unit (HU) measurement, calculation of the Hounsfield unit/hematocrit (HU/Hct) ratio, and combination of visual assessment and attenuation measurement (VA + HU). Methods: NECT of 18 patients with angiographically proven MCAO and 18 patients without MCAO were reviewed by two blinded observers. Visual assessment of presence or absence of a hyperdense sign was followed by HU measurement of both middle cerebral arteries (MCA). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for VA, HU measurement, HU/Hct ratio, and VA + HU measurement. Receiver operating characteristic curve analysis (ROC) was performed to determine the optimal cut-off values for MCAO using attenuation measurements or HU/Hct ratio. Results: Diagnostic sensitivity/specificity was 63 %/91 % for VA, 56 %/88 % for attenuation measurement, 68 %/81 % for HU/Hct ratio, and 75 %/78 % for VA + HU. ROC curve analysis revealed cut-off values of >42.5 HU for attenuation measurements and >1.12 HU/Hct for HU/Hct ratio. Conclusion: Combination of visual assessment with additional attenuation measurement with a cut-off value of 42.5 HU is recommended for most sensitive and reliable detection of MCAO on NECT. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this work is to present the software tool ANTONIA, which has been developed to facilitate a quantitative analysis of perfusion-weighted MRI (PWI) datasets in general as well as the subsequent multi-parametric analysis of additional datasets for the specific purpose of acute ischemic stroke patient dataset evaluation.Methods: Three different methods for the analysis of DSC or DCE PWI datasets are currently implemented in ANTONIA, which can be case-specifically selected based on the study protocol. These methods comprise a curve fitting method as well as a deconvolution-based and deconvolution-free method integrating a previously defined arterial input function. The perfusion analysis is extended for the purpose of acute ischemic stroke analysis by additional methods that enable an automatic atlas-based selection of the arterial input function, an analysis of the perfusion-diffusion and DWI-FLAIR mismatch as well as segmentation-based volumetric analyses.Results: For reliability evaluation, the described software tool was used by two observers for quantitative analysis of 15 datasets from acute ischemic stroke patients to extract the acute lesion core volume, FLAIR ratio, perfusion-diffusion mismatch volume with manually as well as automatically selected arterial input functions, and follow-up lesion volume. The results of this evaluation revealed that the described software tool leads to highly reproducible results for all parameters if the automatic arterial input function selection method is used.Conclusion: Due to the broad selection of processing methods that are available in the software tool, ANTONIA is especially helpful to support image-based perfusion and acute ischemic stroke research projects. [ABSTRACT FROM AUTHOR]

Purpose: Infections with Enterohaemorrhagic Escherichia coli typically occur in children causing haemolytic uraemic syndrome (HUS) and neurological symptoms in 20-50 %. Little information is available on the morphology of brain manifestations in adults. The purpose of this study was to identify a characteristic magnetic resonance imaging (MRI) pattern during the outbreak of a novel mutation of Escherichia coli O104:H4. Methods: Patients were recruited from two hospitals between May and July 2011. The MRI protocol included standard anatomical, diffusion-weighted, and susceptibility-sensitive sequences. Results: A total of 104 MRIs of 57 (32 female, 25 male) patients (mean 45.5 ± 18.4 years) showed abnormal signal intensity on 51 MRIs (49 %). Bilateral thalamus (39 %), bilateral pons (35 %), centrum semiovale and splenium of corpus callosum (33 %) were most often involved. Acute lesions were reversible in 81 % of cases. There was no statistically significant association between symptom onset and the MRI findings ( P = 0.2). Conclusions: Neuroimaging findings in this adult patient cohort were non-specific and similar to previous findings in children. A characteristic neuroimaging pattern of an infection with Escherichia coli O104:H4 was not identified. However, bilateral symmetric T2 hyperintense lesions of the thalami and dorsal pons characterized by restricted diffusion suggest a metabolic toxic effect of the disease on the brain. [ABSTRACT FROM AUTHOR]

Objectives: The cerebroarterial system is a complex network of arteries that supply the brain cells with vitally important nutrients and oxygen. The inter-individual differences of the cerebral arteries, especially at a finer level, are still not understood sufficiently. The aim of this work is to present a statistical cerebroarterial atlas that can be used to overcome this problem. Methods: Overall, 700 Time-of-Flight (TOF) magnetic resonance angiography (MRA) data sets of healthy subjects were used for atlas generation. Therefore, the cerebral arteries were automatically segmented in each dataset and used for a quantification of the vessel diameters. After this, each TOF MRA dataset as well as the corresponding vessel segmentation and vessel diameter dataset were registered to the MNI brain atlas. Finally, the registered datasets were used to calculate a statistical cerebroarterial atlas that incorporates information about the average TOF intensity, probability for a vessel occurrence and mean vessel diameter for each voxel. Results: Visual analysis revealed that arteries with a diameter as small as 0.5 mm are well represented in the atlas with quantitative values that are within range of anatomical reference values. Moreover, a highly significant strong positive correlation between the vessel diameter and occurrence probability was found. Furthermore, it was shown that an intensity-based automatic segmentation of cerebral vessels can be considerable improved by incorporating the atlas information leading to results within the range of the inter-observer agreement. Conclusion: The presented cerebroarterial atlas seems useful for improving the understanding about normal variations of cerebral arteries, initialization of cerebrovascular segmentation methods and may even lay the foundation for a reliable quantification of subtle morphological vascular changes. [ABSTRACT FROM AUTHOR]

Objectives: The cerebroarterial system is a complex network of arteries that supply the brain cells with vitally important nutrients and oxygen. The inter-individual differences of the cerebral arteries, especially at a finer level, are still not understood sufficiently. The aim of this work is to present a statistical cerebroarterial atlas that can be used to overcome this problem.Methods: Overall, 700 Time-of-Flight (TOF) magnetic resonance angiography (MRA) datasets of healthy subjects were used for atlas generation. Therefore, the cerebral arteries were automatically segmented in each dataset and used for a quantification of the vessel diameters. After this, each TOF MRA dataset as well as the corresponding vessel segmentation and vessel diameter dataset were registered to the MNI brain atlas. Finally, the registered datasets were used to calculate a statistical cerebroarterial atlas that incorporates information about the average TOF intensity, probability for a vessel occurrence and mean vessel diameter for each voxel.Results: Visual analysis revealed that arteries with a diameter as small as 0.5 mm are well represented in the atlas with quantitative values that are within range of anatomical reference values. Moreover, a highly significant strong positive correlation between the vessel diameter and occurrence probability was found. Furthermore, it was shown that an intensity-based automatic segmentation of cerebral vessels can be considerable improved by incorporating the atlas information leading to results within the range of the inter-observer agreement.Conclusion: The presented cerebroarterial atlas seems useful for improving the understanding about normal variations of cerebral arteries, initialization of cerebrovascular segmentation methods and may even lay the foundation for a reliable quantification of subtle morphological vascular changes. [ABSTRACT FROM AUTHOR]

The authors discuss the position of the European Society of Minimally Invasive Neurological Therapy (ESMINT) and European Society of Neuroradiology (ESNR) on several randomized clinical trials of the effectiveness of endovascular treatment (EVT) for care of acute ischemic stroke (AIS). They evaluate three studies which compare intravenous IV thrombolysis (IVT) recombinant tissue plasminogen activator (rTPA) therapy with endovascular surgery.

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