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BackgroundThe adequacy of leptomeningeal collateral flow has a pivotal role in determining clinical outcome in acute ischemic stroke. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral score is among the most commonly used scales for measuring this flow. It is based on the extent and rate of retrograde collateral flow to the impaired territory on angiography.ObjectiveTo evaluate inter- and intraobserver agreementin angiographic leptomeningeal collateral flow assessment.Materials and methodsThirty pretreatment angiogram video loops (frontal and lateral view), chosen from the randomized controlled trial THRombectomie des Artères CErebrales (THRACE), were sent for grading in an electronic file. 19 readers participated, including eight who had access to a training set before the first grading. 13 readers made a double evaluation, 3 months apart.ResultsOverall agreement among the 19 observers was poor (κ = 0,16 ± 6,5.10 -3), and not improved with prior training (κ = 0,14 ± 0,016). Grade 4 showed the poorest interobserver agreement (κ=0.18±0.002) while grades 0 and 1 were associated with the best results (κ=0.52±0.001 and κ=0.43±0.004, respectively). Interobserver agreement increased (κ = 0,27± 0,014) when a dichotomized score, ‘poor collaterals’ (score of 0, 1 or 2) versus ‘good collaterals’ (score of 3 or 4) was used. The intraobserver agreements varied between slight (κ=0.18±0.13) and substantial (κ=0.74±0.1), and were slightly improved with the dichotomized score (from κ=0.19±0.2 to κ=0.79±0.11).ConclusionInter- and intraobserver agreement of collateral circulation grading using the ASITN/SIR score was poor, raising concerns about comparisons among publications. A simplified dichotomized judgment may be a more reproducible assessment when images are rated by the same observer(s) in randomized trials.

BackgroundNeuromuscular block (NMB) used during general anesthesia induces transient skeletal muscle paralysis, but patient movements during endovascular coiling still occur to some degree. Compared with moderate NMB, deep NMB may further improve the intervention condition during endovascular coiling for unruptured cerebral aneurysms; however, little research has focused on the angiographic image quality.MethodsThis prospective, randomized, double-blind clinical trial included 58 patients treated for unruptured cerebral aneurysms with endovascular coiling under general anesthesia. Patients were randomly allocated to either the deep NMB group (post-tetanic count 1 or 2) or the moderate NMB group (train-of-four 1 or 2). The primary outcome was the proportion of patients with a satisfactory intervention condition assessed by surgeons after the procedure using a 5-point intervention condition rating scale (ICRS) from 1 (unable to obtain image) to 5 (optimal); ICRS 5 was defined as satisfactory.ResultsThere were significantly more cases of satisfactory intervention condition in the deep NMB group than in the moderate NMB group (82.1% vs 51.7%, p=0.015). The frequency of each ICRS score was significantly different between the groups (ICRS 5/4/3/2/1: 23/5/0/0/0 vs 15/9/2/3/0, p=0.035). The incidence of major patient movement requiring rescue muscle relaxant was 10.3% in the moderate NMB group and 0% in the deep NMB group (p=0.237). The drugs used to maintain hemodynamic stability were not significantly different between the two groups.ConclusionsDeep NMB improves the intervention condition during endovascular coiling by improving the image quality.

Abstract BACKGROUND: Computerized tomography angiography (CTA) is commonly used to diagnose ruptured cerebral aneurysms with sensitivities reported as high as 97% to 100%. Studies validating CTA accuracy in the setting of subarachnoid hemorrhage (SAH) are scarce and limited by small sample sizes. OBJECTIVE: To evaluate the diagnostic accuracy of CTA in detecting intracranial aneurysms in the setting of SAH. METHODS: A single-center, retrospective cohort of 643 patients was reviewed. A total of 401 patients were identified whose diagnostic workup included both CTA and confirmatory digital subtraction angiography (DSA). Aneurysms missed by CTA but diagnosed by DSA were further stratified by size and location. RESULTS: Three hundred and thirty aneurysms were detected by CTA while DSA detected a total of 431 aneurysms. False positive CTA results were seen for 24 aneurysms. DSA identified 125 aneurysms that were missed by CTA and 83.2% of those were <5 mm in diameter. The sensitivity of CTA was 57.6% for aneurysms smaller than 5 mm in size, and 45% for aneurysms originating from the internal carotid artery. The overall sensitivity of CTA in the setting of SAH was 70.7%. CONCLUSION: The accuracy of CTA in the diagnosis of ruptured intracranial aneurysm may be lower than previously reported. CTA has a low sensitivity for aneurysms less than 5 mm in size, in locations adjacent to bony structures, and for those arising from small caliber parent vessels. It is our recommendation that CTA should be used with caution when used alone in the diagnosis of ruptured intracranial aneurysms.

Attribution of vascular pathophysiology to reductions in cerebrovascular reactivity (CVR) is confounded by subjective assessment and the normal variation between anatomic regions. This study aimed to develop an objective scoring assessment of abnormality. CVR was measured as the ratio of the blood-oxygen-level-dependent magnetic resonance signal response divided by an increase in CO2, standardized to eliminate variability. A reference normal atlas was generated by coregistering the CVR maps from 46 healthy subjects into a standard space and calculating the mean and standard deviation (s.d.) of CVR for each voxel. Example CVR studies from 10 patients with cerebral vasculopathy were assessed for abnormality, by normalizing each patient's CVR to the same standard space as the atlas, and assigning a z-score to each voxel relative to the mean and s.d. of the corresponding atlas voxel. Z-scores were color coded and superimposed on their anatomic scans to form CVR z-maps. We found the CVR z-maps provided an objective evaluation of abnormality, enhancing our appreciation of the extent and distribution of pathophysiology compared with CVR maps alone. We concluded that CVR z-maps provide an objective, improved form of evaluation for comparisons of voxel-specific CVR between subjects, and across tests sites.

BackgroundDespite growing interest in the transradial approach for neurovascular procedures, prospective data about the learning curve for neurointerventionalists adopting this approach are limited.MethodsA subsequent prospective series of 50 consecutive right transradial diagnostic cerebral arteriograms was compared with our initial institutional experience using a procedural staging system. The primary outcome was the ability to achieve the predefined procedural goals using the radial approach. Secondary outcomes included the technical ability to access and inject each supraaortic artery of interest and the incidence of complications.ResultsThe primary outcome was achieved in 49 patients (98%) compared with 88% in the initial series (p=0.05). One stage 2 failure (2%) occurred. Crossover to the transfemoral approach occurred in one patient (2%) compared with 8% in the initial series (p=0.16). All supraaortic arteries of interest were accessed and injected with success rates between 93% and 100%. There were no major complications and two minor complications.ConclusionNeurointerventionalists can overcome the right transradial learning curve and achieve high success rates and low crossover rates after performing 30–50 cases.

Radiomics has potential for reflecting the differences in glioma perfusion heterogeneity between arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) imaging. The aim of this study was to compare radiomic features of ASL and DSC imaging-derived parameters (cerebral blood flow, CBF) and assess radiomics-based classification models for low-grade gliomas (LGGs) and high-grade gliomas (HGGs) using their parameters. The ASL-CBF and DSC-relative CBF of 46 glioma patients were normalized (ASL-nCBF and DSC-nrCBF) for data analysis. For each map, 91 radiomic features were extracted from the tumor volume. Seventy-five radiomic features were significantly different ( P  < 0.00055) between ASL-nCBF and DSC-nrCBF. Positive correlations were observed in 75 radiomic features between ASL-nCBF and DSC-nrCBF. Even though ASL imaging underestimated CBF compared with DSC imaging, there were significant correlations ( P  < 0.00055) in the first-order-based mean, median, 90 th percentile, and maximum. Texture analysis showed that ASL-nCBF and DSC-nrCBF characterized similar perfusion patterns, while ASL-nCBF could evaluate perfusion heterogeneity better. The areas under the curve of the ASL-nCBF and DSC-nrCBF radiomics-based classification models for gliomas were 0.888 and 0.962, respectively. Radiomics in ASL and DSC imaging is useful for characterizing glioma perfusion patterns quantitatively and for classifying LGGs and HGGs.

The aim of this study is to identify image-based morphological parameters that correlate with human intracranial aneurysm (IA) rupture. For 45 patients with terminal or sidewall saccular IAs (25 unruptured, 20 ruptured), three-dimensional geometries were evaluated for a range of morphological parameters. In addition to five previously studied parameters (aspect ratio, aneurysm size, ellipticity index, nonsphericity index, and undulation index), we defined three novel parameters incorporating the parent vessel geometry (vessel angle, aneurysm [inclination] angle, and [aneurysm-to-vessel] size ratio) and explored their correlation with aneurysm rupture. Parameters were analyzed with a two-tailed independent Student's t test for significance; significant parameters (P < 0.05) were further examined by multivariate logistic regression analysis. Additionally, receiver operating characteristic analyses were performed on each parameter. Statistically significant differences were found between mean values in ruptured and unruptured groups for size ratio, undulation index, nonsphericity index, ellipticity index, aneurysm angle, and aspect ratio. Logistic regression analysis further revealed that size ratio (odds ratio, 1.41; 95% confidence interval, 1.03-1.92) and undulation index (odds ratio, 1.51; 95% confidence interval, 1.08-2.11) had the strongest independent correlation with ruptured IA. From the receiver operating characteristic analysis, size ratio and aneurysm angle had the highest area under the curve values of 0.83 and 0.85, respectively. Size ratio and aneurysm angle are promising new morphological metrics for IA rupture risk assessment. Because these parameters account for vessel geometry, they may bridge the gap between morphological studies and more qualitative location-based studies.

•This study evaluated the role of satellite sign in predicting hematoma expansion.•Receiver-operator analysis was used to evaluate the predictive value.•The predictive accuracy of satellite sign was compared with CTA spot sign. Hematoma expansion is related to poor outcome in spontaneous intracerebral hemorrhage (ICH). Recently, a non-enhanced computed tomography (CT) based finding, termed the ‘satellite sign’, was reported to be a novel predictor for poor outcome in spontaneous ICH. However, it is still unclear whether the presence of the satellite sign is related to hematoma expansion. Initial computed tomography angiography (CTA) was conducted within 6h after ictus. Satellite sign on non-enhanced CT and spot sign on CTA were detected by two independent reviewers. The sensitivity and specificity of both satellite sign and spot sign were calculated. Receiver-operator analysis was conducted to evaluate their predictive accuracy for hematoma expansion. This study included 153 patients. Satellite sign was detected in 58 (37.91%) patients and spot sign was detected in 38 (24.84%) patients. Among 37 patients with hematoma expansion, 22 (59.46%) had satellite sign and 23 (62.16%) had spot sign. The sensitivity and specificity of satellite sign for prediction of hematoma expansion were 59.46% and 68.97%, respectively. The sensitivity and specificity of spot sign were 62.16% and 87.07%, respectively. The area under the curve (AUC) of satellite sign was 0.642 and the AUC of spot sign was 0.746. (P=0.157) Our results suggest that the satellite sign is an independent predictor for hematoma expansion in spontaneous ICH. Although spot sign has the higher predictive accuracy, satellite sign is still an acceptable predictor for hematoma expansion when CTA is unavailable.

[...]some authors have called for increasing standardization of reporting among the stroke community using angiographic reperfusion to enhance generalizability. 14 15 In this paper we review the current grading systems for recanalization/reperfusion, discuss the current controversies in grading systems and the need for standardization of recanalization and reperfusion in trial reporting. [...]we suggest delayed angiographic reassessment as a means of controlling for thrombolytic or thrombogenic phenomena that may occur immediately after completion of the procedure and may potentially influence the clinical outcome.

BackgroundThe aim of this study is to assess the feasibility of identifying the hemodynamic status of intracranial atherosclerotic stenosis (ICAS) using angio-based fractional flow (FF) calculated from a single angiographic view, with wire-based FF as the reference standard.MethodThe study retrospectively recruited 100 ICAS patients who underwent pressure wire measurement and digital subtraction angiography. The AccuICAD software was used to calculate angio-based FF, with the wire-measured value serving as the reference standard for evaluating the accuracy, consistency, and diagnostic performance of angio-based FF.ResultsThe mean±SD value of wire-based FF was 0.77±0.18, while the mean value of angio-based FF was 0.77±0.19. A good correlation between angio-based FF and wire-based FF was evident (r=0.90, P<0.001), with good agreement (mean difference 0.00±0.08). The diagnostic accuracy of angio-based FF and percent diameter stenosis (DS%) were 93.23% versus 72.18%, 91.73% versus 72.93%, and 89.47% versus 78.95% for predicted wire-based FF thresholds of 0.70, 0.75, and 0.80, respectively. The area under the curve (AUC) values for angio-based FF and DS% were 0.975 versus 0.822, 0.970 versus 0.814, and 0.943 versus 0.826 at the respective thresholds, respectively.ConclusionThe FF calculated from a single angiographic view can be considered an effective tool for functional assessment of cerebral arterial stenosis.