CAVE: Cerebral artery-vein segmentation in digital subtraction angiography.

Cerebral X-ray digital subtraction angiography (DSA) is a widely used imaging technique in patients with neurovascular disease, allowing for vessel and flow visualization with high spatio-temporal resolution. Automatic artery-vein segmentation in DSA plays a fundamental role in vascular analysis with quantitative biomarker extraction, facilitating a wide range of clinical applications. The widely adopted U-Net applied on static DSA frames often struggles with disentangling vessels from subtraction artifacts. Further, it falls short in effectively separating arteries and veins as it disregards the temporal perspectives inherent in DSA. To address these limitations, we propose to simultaneously leverage spatial vasculature and temporal cerebral flow characteristics to segment arteries and veins in DSA. The proposed network, coined CAVE, encodes a 2D+time DSA series using spatial modules, aggregates all the features using temporal modules, and decodes it into 2D segmentation maps. On a large multi-center clinical dataset, CAVE achieves a vessel segmentation Dice of 0.84 (±0.04) and an artery-vein segmentation Dice of 0.79 (±0.06). CAVE surpasses traditional Frangi-based k-means clustering (P < 0.001) and U-Net (P < 0.001) by a significant margin, demonstrating the advantages of harvesting spatio-temporal features. This study represents the first investigation into automatic artery-vein segmentation in DSA using deep learning. The code is publicly available at https://github.com/RuishengSu/CAVE_DSA.

Automated image registration of cerebral digital subtraction angiography.

PURPOSE: Our aim is to automatically align digital subtraction angiography (DSA) series, recorded before and after endovascular thrombectomy. Such alignment may enable quantification of procedural success. METHODS: Firstly, we examine the inherent limitations for image registration, caused by the projective characteristics of DSA imaging, in a representative set of image pairs from thrombectomy procedures. Secondly, we develop and assess various image registration methods (SIFT, ORB). We assess these methods using manually annotated point correspondences for thrombectomy image pairs. RESULTS: Linear transformations that account for scale differences are effective in aligning DSA sequences. Two anatomical landmarks can be reliably identified for registration using a U-net. Point-based registration using SIFT and ORB proves to be most effective for DSA registration and are applicable to recordings for all patient sub-types. Image-based techniques are less effective and did not refine the results of the best point-based registration method. CONCLUSION: We developed and assessed an automated image registration approach for cerebral DSA sequences, recorded before and after endovascular thrombectomy. Accurate results were obtained for approximately 85% of our image pairs.

Comparison of diffusion weighted imaging b0 with T2*-weighted gradient echo or susceptibility weighted imaging for intracranial hemorrhage detection after reperfusion therapy for ischemic stroke.

PURPOSE: Diffusion-weighted imaging (DWI) b0 may be able to substitute T2*-weighted gradient echo (GRE) or susceptibility-weighted imaging (SWI) in case of comparable detection of intracranial hemorrhage (ICH), thereby reducing MRI examination time. We evaluated the diagnostic accuracy of DWI b0 compared to T2*GRE or SWI for detection of ICH after reperfusion therapy for ischemic stroke. METHODS: We pooled 300 follow-up MRI scans acquired within 1 week after reperfusion therapy. Six neuroradiologists each rated DWI images (b0 and b1000; b0 as index test) of 100 patients and, after a minimum of 4 weeks, T2*GRE or SWI images (reference standard) paired with DWI images of the same patients. Readers assessed the presence of ICH (yes/no) and type of ICH according to the Heidelberg Bleeding Classification. We determined the sensitivity and specificity of DWI b0 for detection of any ICH, and the sensitivity for detection of hemorrhagic infarction (HI1 & HI2) and parenchymal hematoma (PH1 & PH2). RESULTS: We analyzed 277 scans of ischemic stroke patients with complete image series and sufficient image quality (median age 65 years [interquartile range, 54-75], 158 [57%] men). For detection of any ICH on DWI b0, the sensitivity was 62% (95% CI: 50-76) and specificity 96% (95% CI: 93-99). The sensitivity of DWI b0 was 52% (95% CI: 28-68) for detection of hemorrhagic infarction and 84% (95% CI: 70-92) for parenchymal hematoma. CONCLUSION: DWI b0 is inferior for detection of ICH compared to T2*GRE/SWI, especially for smaller and more subtle hemorrhages. Follow-up MRI protocols should include T2*GRE/SWI for detection of ICH after reperfusion therapy.

Interobserver Agreement on Intracranial Hemorrhage on Magnetic Resonance Imaging in Patients With Ischemic Stroke.

BACKGROUND: The Heidelberg Bleeding Classification, developed for computed tomography, is also frequently used to classify intracranial hemorrhage (ICH) on magnetic resonance imaging. Additionally, the presence of any ICH is frequently used as (safety) outcome measure in clinical stroke trials that evaluate acute interventions. We assessed the interobserver agreement on the presence of any ICH and the type of ICH according to the Heidelberg Bleeding Classification on magnetic resonance imaging in patients treated with reperfusion therapy. METHODS: We used 300 magnetic resonance imaging scans including susceptibility-weighted imaging or T2*-weighted gradient echo imaging of ischemic stroke patients within 1 week after reperfusion therapy. Six observers, blinded to clinical characteristics except for suspected location of the infarction, independently rated ICH according to the Heidelberg Bleeding Classification in random pairs. Percent agreement and Cohen's kappa (κ) were estimated for the presence of any ICH (yes/no), and for agreement on the Heidelberg Bleeding Classification class 1 and 2. For the Heidelberg Bleeding Classification class 1 and 2, weighted κ was estimated to take the degree of disagreement into account. RESULTS: In 297 of 300 scans, the quality of scans was sufficient to score ICH. Observers agreed on the presence or absence of any ICH in 264 of 297 scans (88.9%; κ 0.78 [95% CI, 0.71-0.85]). There was agreement on the Heidelberg Bleeding Classification class 1 and 2 and no ICH in class 1 and 2 in 226 of 297 scans (76.1%; κ 0.63 [95% CI, 0.56-0.69]; weighted κ 0.90 [95% CI, 0.87-0.93]). CONCLUSIONS: The presence of any ICH can be reliably scored on magnetic resonance imaging and can, therefore, be used as (safety) outcome measure in clinical stroke trials that evaluate acute interventions. Agreement of ICH types according to the Heidelberg Bleeding Classification is substantial and disagreements are small.

Spontaneous Iliac Vein Ruptures: A Systematic Review.

INTRODUCTION: Spontaneous iliac vein rupture is a rare, but frequently lethal condition. It is important to timely recognize its clinical features and immediately start adequate treatment. We aimed to increase awareness to clinical features, specific diagnostics, and treatment strategies of spontaneous iliac vein rupture by evaluating the current literature. METHODS: A systematic search was conducted in EMBASE, Ovid MEDLINE, Cochrane, Web of Science, and Google Scholar from inception until January 23, 2023, without any restrictions. Two reviewers independently screened for eligibility and selected studies describing a spontaneous iliac vein rupture. Patient characteristics, clinical features, diagnostics, treatment strategies, and survival outcomes were collected from included studies. RESULTS: We included 76 cases (64 studies) from the literature, mostly presenting with left-sided spontaneous iliac vein rupture (96.1%). Patients were predominantly female (84.2%), had a mean age of 61 years, and frequently presented with a concomitant deep vein thrombosis (DVT) (84.2%). After various follow-up times, 77.6% of the patients survived, either after conservative, endovascular, or open treatment. Endovenous or hybrid procedures were frequently performed if the diagnose was made before treatment, and almost all survived. Open treatment was common if the venous rupture was missed, for some cases leading to death. CONCLUSION: Spontaneous iliac vein rupture is rare and easily missed. The diagnose should at least be considered for middle-aged and elderly females presenting with hemorrhagic shock and concomitant left-sided DVT. There are various treatment strategies for spontaneous iliac vein rupture. An early diagnose brings options for endovenous treatment, which seems to have good survival outcomes based on previously described cases.

Deep-Learning-Based Thrombus Localization and Segmentation in Patients with Posterior Circulation Stroke.

Thrombus volume in posterior circulation stroke (PCS) has been associated with outcome, through recanalization. Manual thrombus segmentation is impractical for large scale analysis of image characteristics. Hence, in this study we develop the first automatic method for thrombus localization and segmentation on CT in patients with PCS. In this multi-center retrospective study, 187 patients with PCS from the MR CLEAN Registry were included. We developed a convolutional neural network (CNN) that segments thrombi and restricts the volume-of-interest (VOI) to the brainstem (Polar-UNet). Furthermore, we reduced false positive localization by removing small-volume objects, referred to as volume-based removal (VBR). Polar-UNet is benchmarked against a CNN that does not restrict the VOI (BL-UNet). Performance metrics included the intra-class correlation coefficient (ICC) between automated and manually segmented thrombus volumes, the thrombus localization precision and recall, and the Dice coefficient. The majority of the thrombi were localized. Without VBR, Polar-UNet achieved a thrombus localization recall of 0.82, versus 0.78 achieved by BL-UNet. This high recall was accompanied by a low precision of 0.14 and 0.09. VBR improved precision to 0.65 and 0.56 for Polar-UNet and BL-UNet, respectively, with a small reduction in recall to 0.75 and 0.69. The Dice coefficient achieved by Polar-UNet was 0.44, versus 0.38 achieved by BL-UNet with VBR. Both methods achieved ICCs of 0.41 (95% CI: 0.27-0.54). Restricting the VOI to the brainstem improved the thrombus localization precision, recall, and segmentation overlap compared to the benchmark. VBR improved thrombus localization precision but lowered recall.

Spatio-temporal deep learning for automatic detection of intracranial vessel perforation in digital subtraction angiography during endovascular thrombectomy.

Intracranial vessel perforation is a peri-procedural complication during endovascular therapy (EVT). Prompt recognition is important as its occurrence is strongly associated with unfavorable treatment outcomes. However, perforations can be hard to detect because they are rare, can be subtle, and the interventionalist is working under time pressure and focused on treatment of vessel occlusions. Automatic detection holds potential to improve rapid identification of intracranial vessel perforation. In this work, we present the first study on automated perforation detection and localization on X-ray digital subtraction angiography (DSA) image series. We adapt several state-of-the-art single-frame detectors and further propose temporal modules to learn the progressive dynamics of contrast extravasation. Application-tailored loss function and post-processing techniques are designed. We train and validate various automated methods using two national multi-center datasets (i.e., MR CLEAN Registry and MR CLEAN-NoIV Trial), and one international multi-trial dataset (i.e., the HERMES collaboration). With ten-fold cross-validation, the proposed methods achieve an area under the curve (AUC) of the receiver operating characteristic of 0.93 in terms of series level perforation classification. Perforation localization precision and recall reach 0.83 and 0.70 respectively. Furthermore, we demonstrate that the proposed automatic solutions perform at similar level as an expert radiologist.

Treatment of ruptured subclavian steal flow-related vertebrobasilar junction aneurysms: Case report on surgical and endovascular considerations from two cases.

INTRODUCTION: Subclavian steal phenomenon causes retrograde flow through the vertebral artery, ipsilateral to the affected subclavian artery, which rarely leads to flow-related vertebrobasilar junction (VBJ) aneurysms. CASE DESCRIPTIONS: We describe two cases of subarachnoid hemorrhage from such ruptured aneurysms in which the retrograde flow direction in the vertebral artery complicated surgical and endovascular treatment. DISCUSSION: Reversed flow in the vertebral artery, ipsilateral to the stenotic subclavian artery leads to a lack of proximal control in surgical clipping of these VBJ aneurysms and jeopardizes stability of coil and stent placement in endovascular aneurysm treatments in this setting. CONCLUSION: From these 2 experiences over 7 years, treatment considerations emerged for future cases.

autoTICI: Automatic Brain Tissue Reperfusion Scoring on 2D DSA Images of Acute Ischemic Stroke Patients.

The Thrombolysis in Cerebral Infarction (TICI) score is an important metric for reperfusion therapy assessment in acute ischemic stroke. It is commonly used as a technical outcome measure after endovascular treatment (EVT). Existing TICI scores are defined in coarse ordinal grades based on visual inspection, leading to inter- and intra-observer variation. In this work, we present autoTICI, an automatic and quantitative TICI scoring method. First, each digital subtraction angiography (DSA) acquisition is separated into four phases (non-contrast, arterial, parenchymal and venous phase) using a multi-path convolutional neural network (CNN), which exploits spatio-temporal features. The network also incorporates sequence level label dependencies in the form of a state-transition matrix. Next, a minimum intensity map (MINIP) is computed using the motion corrected arterial and parenchymal frames. On the MINIP image, vessel, perfusion and background pixels are segmented. Finally, we quantify the autoTICI score as the ratio of reperfused pixels after EVT. On a routinely acquired multi-center dataset, the proposed autoTICI shows good correlation with the extended TICI (eTICI) reference with an average area under the curve (AUC) score of 0.81. The AUC score is 0.90 with respect to the dichotomized eTICI. In terms of clinical outcome prediction, we demonstrate that autoTICI is overall comparable to eTICI.

Residual Splenic Volume after Main Splenic Artery Embolization is Independent of the Underlying Disease.

PURPOSE: To assess the safety and efficacy of main splenic artery embolization. To assess the potential difference post-embolization of the residual splenic volume in patients embolized for trauma versus those embolized for (pseudo)aneurysms. MATERIALS AND METHODS: A retrospective analysis was performed on a cohort of 65 patients (36 males) who underwent pre- and post-embolization computed tomography. Patients' demographics, pre- and post-interventional medical and radiological data were gathered. Splenic volume calculations were semi-automatically performed via a workstation. Patients with splenic aneurysms or pseudoaneurysms of the main splenic artery (group 1) were compared to those with splenic rupture (group 2) using Wilcoxon rank tests. RESULTS: The main indications for splenic artery embolization were splenic rupture (n = 22; 34%) and splenic pseudoaneurysm (n = 19; 29%). The technical success rate was n = 63; 97%. The procedure-related complication rate was n = 7; 11%, including abscess formation (n = 5; 8%), re-bleeding (n = 1; 1.5 %) and pseudoaneurysm re-opening (n = 1; 1.5%). The overall 30-day mortality was n = 7; 11%.Median follow-up for groups 1 and 2 was 1163 days (61-3946 days) and 702 days (43-2095 days) respectively. When processable (n = 23), the splenic volume in group 1 (n = 7) was 311 cm3 and 257 cm3 (p = 0.1591) before and after embolization respectively, and in group 2 (n = 16) it was 261 cm3 and 215 cm3 (p = 0.4688), respectively. CONCLUSIONS: Main splenic artery embolization is efficacious, with low procedure-related complication and 30-day mortality rates. No significant differences in residual post-embolization splenic volume were found between patients treated for splenic rupture versus those treated for splenic arterial (pseudo)aneurysm.

Multicenter, retrospective analysis of endovascular treatment for acute ischemic stroke in nonagenarians.

BACKGROUND: With the increasing age of acute stroke patients being admitted to hospitals, more data are needed on indications, complications and outcome of endovascular treatment (EVT) in the very elderly. METHODS: Retrospective observational study with data collection from Belgian, Swiss, Canadian comprehensive stroke centers and Swedish EVT National database. All patients with acute ischemic stroke were eligible if aged older than or ≥90 years and treated with EVT ± pretreatment with intravenous thrombolysis (IVT). Safety assessment comprised presence of periprocedural complications, hemorrhagic transformation or other adverse events (<7days). Efficacy and outcome measures were successful recanalization (modified Treatment In Cerebral Infarction (mTICI) score ≥2b), favorable clinical outcome (modified Rankin Score (mRS) 0-2) and 3-months mortality. RESULTS: Inclusion of 112 nonagenarians (mean age 93.3 ± 2.5 years; 76.8% women; pre-mRS ≤2 in 69.4%). Pretreatment with IVT was performed in 54.7%. In 74.6% successful recanalization (mTICI ≥2b) was achieved. Favorable outcome (mRS ≤2) was seen in 16.4% and 3-months mortality was 62.3%. Multivariate logistic regression analysis showed younger age (odds ratio [OR] 2.99; 1.29-6.95; P = .011) and lower prestroke mRS (OR 13.46; 2.32-78.30; P = .004) as significant predictors for good clinical outcome at 90 days. CONCLUSIONS: Our observational study on EVT in nonagenarians demonstrates the need for careful patient selection. A substantial proportion of nonagenarians shows an unfavorable clinical outcome and high mortality, despite acceptable recanalization rates. A high prestroke disability (mRS) and advancing age predict an unfavorable outcome. Treatment decisions should be made on case-by-case evaluation, keeping in mind limited chances of favorable outcome and high risk of mortality.

Comprehensive routine diagnostic screening to identify predictive mutations, gene amplifications, and microsatellite instability in FFPE tumor material.

BACKGROUND: Sensitive and reliable molecular diagnostics is needed to guide therapeutic decisions for cancer patients. Although less material becomes available for testing, genetic markers are rapidly expanding. Simultaneous detection of predictive markers, including mutations, gene amplifications and MSI, will save valuable material, time and costs. METHODS: Using a single-molecule molecular inversion probe (smMIP)-based targeted next-generation sequencing (NGS) approach, we developed an NGS panel allowing detection of predictive mutations in 33 genes, gene amplifications of 13 genes and microsatellite instability (MSI) by the evaluation of 55 microsatellite markers. The panel was designed to target all clinically relevant single and multiple nucleotide mutations in routinely available lung cancer, colorectal cancer, melanoma, and gastro-intestinal stromal tumor samples, but is useful for a broader set of tumor types. RESULTS: The smMIP-based NGS panel was successfully validated and cut-off values were established for reliable gene amplification analysis (i.e. relative coverage ≥3) and MSI detection (≥30% unstable loci). After validation, 728 routine diagnostic tumor samples including a broad range of tumor types were sequenced with sufficient sensitivity (2.4% drop-out), including samples with low DNA input (< 10 ng; 88% successful), low tumor purity (5-10%; 77% successful), and cytological material (90% successful). 75% of these tumor samples showed ≥1 (likely) pathogenic mutation, including targetable mutations (e.g. EGFR, BRAF, MET, ERBB2, KIT, PDGFRA). Amplifications were observed in 5.5% of the samples, comprising clinically relevant amplifications (e.g. MET, ERBB2, FGFR1). 1.5% of the tumor samples were classified as MSI-high, including both MSI-prone and non-MSI-prone tumors. CONCLUSIONS: We developed a comprehensive workflow for predictive analysis of diagnostic tumor samples. The smMIP-based NGS analysis was shown suitable for limited amounts of histological and cytological material. As smMIP technology allows easy adaptation of panels, this approach can comply with the rapidly expanding molecular markers.

Very Late Leptomeningeal Collaterals-Potential New Way to Subdivide Modified Thrombolysis in Cerebral Ischemia (mTICI) 2B.

BACKGROUND: Studies have shown that the modified thrombolysis in cerebral ischemia (mTICI) 2B score is associated with better functional outcome; however, 50-99% reperfusion is a large range and there may be factors which can differentiate this further. The effects of very late leptomeningeal collaterals (VLLC) on mTICI-2B patients were studied. METHOD: A prospectively collected registry of anterior circulation AIS patients treated with the EmboTrap revascularization device from 2013 to 2016 was evaluated. Imaging parameters and timings, including the mTICI score were verified by an external core laboratory blinded to the clinical data. The final angiogram was examined for the appearance of VLLC in predicting 3­month outcomes including excellent functional outcomes, defined as modified Rankin scale (mRS) 0-1, bleeding risk and mortality. RESULTS: A total of 177 consecutive anterior circulation stroke patients were included in the analysis. Of these 94 (53.1%) achieved only mTICI-2B reperfusion, 16/94 (17.0%) patients achieved excellent functional outcomes at 3 months and 26 (27.7%) had hyperdensity on follow-up computed tomography (CT). On univariate analysis, the presence of VLLC was inversely associated with excellent functional outcomes at 3 months and positively associated with mortality in patients with mTICI-2B reperfusion. On multivariate analysis VLLC was inversely associated with excellent outcomes (odds ratio 0.075, 95% confidence interval 0.007-0.765, P = 0.029) but not associated with mortality. CONCLUSION: The mTICI-2B grade may be further refined by secondary radiological markers. The VLLC sign is associated with the loss of excellent functional outcomes at 3 months. It is a simple sign to discriminate mTICI-2B into different grades but should be verified in larger populations from other centers.

A comprehensive report of long-term outcomes after catheter-directed thrombolysis for occluded infrainguinal bypass grafts.

OBJECTIVE: The objective of this study was to assess the technical and short- and long-term clinical outcomes of catheter-directed thrombolysis (CDT) with urokinase for occluded infrainguinal bypass grafts. In addition, factors associated with technical success and amputation-free survival were assessed. METHODS: A retrospective analysis of a cohort of patients treated with catheter-directed urokinase-based thrombolysis for occluded infrainguinal bypass grafts was conducted between January 2000 and December 2015. Demographics, procedural data, and short- and long-term outcome data, including patency rates of the bypasses, limb salvage, and overall survival, were collected. Statistical models for clustered data were applied to assess predictive factors. RESULTS: In 177 patients, 251 CDTs were performed on 204 bypasses. In 209 procedures (83.3%), the occluded bypass was reopened; clinical disappearance of ischemic symptoms occurred after 157 procedures (62.6%). Premature cessation of thrombolysis occurred in 33 procedures (13.2%), and periprocedural and postprocedural complications were noted in 91 patients (36.3%). Factors associated with long-term limb salvage are fewer vascular interventions before CDT (P = .0003), higher number of patent outflow vessels before start of CDT (P < .0001), and higher number of patent outflow vessels after CDT (P < .0001). The 1- and 5-year patency rates of bypasses after successful CDT were 64.6% and 48.9%; amputation-free survival after 1 year, 5 years, and 7 years was 81.5%, 71.3%, and 70.5%, respectively. CONCLUSIONS: Clinical success after CDT was observed in 62% of procedures with an associated complication rate of 36%. Patent outflow vessels before and after CDT are factors associated with long-term limb salvage. Amputation-free survival after 5 years is 71.3%.

Posterior communicating and anterior communicating arteries on pre-thrombectomy computed tomography scans are associated with good outcomes irrespective of leptomeningeal collateral status.

BACKGROUND: Collateral blood flow is known to be an important factor that sustains the penumbra during acute stroke. We looked at both the leptomeningeal collateral circulation and the presence of anterior and posterior communicating arteries to determine the factors associated with good outcomes and mortality. METHODS: We included all patients with acute ischaemic stroke in the anterior circulation, who underwent thrombectomy with the same thrombectomy device from 2013 to 2016. We assessed the leptomeningeal circulation by the Tan, Miteff and Maas validated scoring systems on pre-treatment computed tomographic angiography scans and looked at collateral flow through anterior and posterior communicating arteries. The results were good functional outcomes at 3 months (modified Rankin scale 0-2) and mortality. RESULTS: A total of 147 consecutive acute stroke patients treated with the Embotrap device were included with a median National Institutes of Health stroke scale of 15 (range 2-26). On multivariate analysis only younger age (odds ratio (OR) 0.96/year, 95% confidence interval (CI) 0.94-0.99, P = 0.026), lower National Institutes of Health stroke scale score (OR 0.87/point, 95% CI 0.80-0.93, P < 0.001), number of attempts (OR 0.80/attempt, 95% CI 0.65-0.99, P = 0.043) and the presence of a patent anterior communicating artery (OR 14.03, 95% CI 1.42-139.07, P = 0.024) were associated with good functional outcomes. The number of attempts (OR 1.66/attempt, 95% CI 1.21-2.29, P = 0.002) was significantly associated with mortality and the presence of a patent posterior communicating artery (OR 0.098, 95% CI 0.016-0.59, P = 0.011) was inversely associated with mortality. CONCLUSIONS: Our study shows that the presence of anterior and posterior communicating arteries is significantly associated with good functional outcomes and reduced mortality, respectively, independent of the leptomeningeal circulation status.

Intracranial Stenting after Failure of Thrombectomy with the emboTrap® Device.

BACKGROUND: Approved alternatives in the guidelines for acute ischemic stroke patients who have failed intracranial thrombectomy are lacking. Primary permanent intracranial stenting was initially used in the era before thrombectomy and might still be a useful rescue treatment in acute stroke patients suffering from ongoing large vessel occlusion refractory to thrombectomy. METHODS: The prospectively collected registry of patients with acute stroke caused by large vessel occlusions and treated with the emboTrap® device in Karolinska Hospital from October 2013 through March 2017 were retrospectively reviewed. Clinical outcome of non-recanalized patients with a thrombolysis in cerebral infarction (TICI) score of 0-1 after failed thrombectomy were compared with those who were treated with permanent intracranial stenting as rescue therapy. Favorable outcome was defined as modified Rankin scale 0-2. RESULTS: The emboTrap® device was used in 201 patients. Persistent re-occlusions on withdrawal of the thrombectomy device were seen in 26 patients (13%) and of those, 12 individuals (46%) were treated with intracranial stenting. Baseline National Institutes of Health stroke scale (NIHSS), occlusion site, and onset-to-puncture time did not differ between the stenting group and the non-recanalized group. During the procedure half dose (5/12 patients) or full dose abciximab (6/12 patients), or aspirin (1/12 patient) was given intravenously immediately after stent placement. In 2 patients (17%) multiple stents were implanted. The stenting group had better functional outcomes at 3 months compared to the non-stenting group with 8/12 (66%) vs. 3/14 (21.4%, p < 0.05). Of the patients 5 (36%) in the non-stented group had died at 3 months follow-up, whereas mortality in the stenting cohort was 0% (p < 0.05) and no symptomatic intracranial hemorrhage (ICH) occurred in either group. CONCLUSION: Intracranial stenting after failure of recanalization with thrombectomy led to a better rate of clinical outcome than leaving the patient non-recanalized. The required antiplatelet therapy, predominantly abciximab, did not lead to additional ICH.

Alberta Stroke Program Early CT Score Versus Computed Tomographic Perfusion to Predict Functional Outcome After Successful Reperfusion in Acute Ischemic Stroke.

Background and Purpose- We aimed to compare the ability of conventional Alberta Stroke Program Early CT Score (ASPECTS), automated ASPECTS, and ischemic core volume on computed tomographic perfusion to predict clinical outcome in ischemic stroke because of large vessel occlusion ≤18 hours after symptom onset. Methods- We selected patients with acute ischemic stroke from the CRISP study (Computed Tomographic Perfusion to Predict Response to Recanalization in Ischemic Stroke Project) with successful reperfusion (modified treatment in cerebral ischemia score 2b or 3). We used e-ASPECTS software to calculate automated ASPECTS and RAPID software to estimate ischemic core volumes. We studied associations between these imaging characteristics and good outcome (modified Rankin Scale score, 0-2) or poor outcome (modified Rankin Scale score, 4-6) in univariable and multivariable analysis, after adjustment for relevant clinical confounders. Results- We included 156 patients. Conventional and automated ASPECTS was not associated with good or poor outcome in univariable analysis ( P=nonsignificant for all). Automated ASPECTS was associated with good outcome in multivariable analysis ( P=0.02) but not with poor outcome. Ischemic core volume was associated with good ( P<0.01) and poor outcome ( P=0.04) in univariable and multivariable analysis ( P=0.03 and P=0.02, respectively). Computed tomographic perfusion predicted good outcome with an area under the curve of 0.62 (95% CI, 0.53-0.71) and optimal cutoff core volume of 15 mL. Conclusions- Ischemic core volume assessed on computed tomographic perfusion is a predictor of clinical outcome among patients in whom endovascular reperfusion is achieved ≤18 hours after symptom onset. In this population, conventional or automated ASPECTS did not predict outcome.

Smaller caliber of the internal carotid artery in patients with ipsilateral aplasia of the A1 segment of the anterior cerebral artery: a study with CTA.

To measure the diameter and the transsectional area of the internal carotid arteries (ICA) on CT Angiography (CTA) in patients with aplasia of the A1-segment of the ACA (A1) and in patients with symmetrical A1, the mean diameter and area of the ICA on both sides were measured at a level of 2 cm below the skull base with a commercially available CT software in 41 consecutive patients with aplasia of A1 observed during a 12-month period on CTA and in 41 control patients with symmetrical A1. The mean diameter of the ipsilateral ICA was 3.83 ± 0.60 mm versus 4.86 ± 0.60 mm as mean diameter of the contralateral ICA and versus 4.40 ± 0.60 mm as mean diameter of both ICAs in the control group of patients. The mean area of the ipsilateral ICA was 11.58 ± 3.80 mm2 versus 18. 82 ± 7.39 mm2 as mean area of the contralateral ICA and versus 15.29 ± 4.42 mm2 as mean area of both ICA in the control group of patients. These differences are statistically highly significant. In patients with symmetrical A1, there was no statistical difference between the diameter or area of both internal carotid arteries. In conclusion, in patients with aplasia of A1, the ipsilateral diameter and area of the cervical ICA is smaller than the diameter and area of the contralateral ICA and smaller than the diameter and area of both internal carotid arteries in patients with symmetrical A1.