Hyperdense Artery Sign Research Articles

Comparison of radiological and clinical characteristics of COVID-19 positive and negative ischemic stroke patients undergoing revascularization: A single-centre Turkish study

ObjectiveWe aimed to compare the radiological and clinical characteristics of COVID-19-positive and -negative acute ischemic stroke (AIS) patients who underwent revascularization and to evaluate whether COVID-19 has an effect on revascularization and outcome in AIS patients with COVID-19 infection. MethodsConsecutive COVID-19 positive and negative AIS patients who underwent intravenous thrombolysis and/or endovascular therapy in our hospital between March 2020 and February 2022 were included in this study. Our study is retrospective and 23 COVID-19 positive patients and 108 COVID-19 negative patients were compared in terms of radiological and clinical characteristics. ResultsHypertension was lower in the COVID-19 positive ischemic stroke group (p=0.029). Admission NIHSS score was higher in COVID-19 positive patients (p=0.041). ASPECTS was found to be lower in COVID-19 positive ischemic stroke patients (p=0.019). The rate of hyperdense artery sign differed between groups (p=0.014) and was higher in the COVID-19 positive ischemic stroke group. The incidence of multi-vessel occlusion was found to be significantly higher in the COVID-19-positive ischemic stroke group (p=0.002). In terms of prognostic features, only the 3-month good outcome rate was statistically significantly lower in the COVID-19-positive ischemic stroke group (p=0.011). ConclusionThis study found that radiologically, COVID-19 may be associated with lower ASPECTS in ischemic stroke patients receiving revascularization treatment and may predispose to multivessel occlusion and hyperdense artery sign. Clinically, COVID-19 may be associated with a more severe initial presentation and worse prognosis at 3 months in ischemic stroke patients undergoing revascularization, but may not affect long-term mortality.

Comparison of Outcomes between Stent Retriever Combined with Contact Aspiration and Contact Aspiration Alone in Patients without Hyperdense Artery Sign/Susceptibility Vessel Sign

PurposeTo examine the relationship between hyperdense artery sign (HAS)/susceptibility vessel sign (SVS) and thrombus composition and evaluate the effect of HAS/SVS status on the association between first-line thrombectomy techniques and outcomes in patients with acute anterior circulation large vessel occlusion (LVO). Materials and MethodsFrom January 2018 to June 2021, 103 consecutive patients with acute anterior circulation LVO (75 [63.1%] men; median age, 66 years) who underwent thrombectomy and for whom the removed clot was available for histological analyses were retrospectively reviewed. The presence of HAS and SVS was assessed on unenhanced computed tomography (CT) and susceptibility-weighted imaging, respectively. Association of first-line thrombectomy techniques (stent retriever [SR] combined with contact aspiration [CA] vs CA alone) with outcomes was assessed according to HAS/SVS status. ResultsAmong the included patients, 55 (53.4%) were HAS/SVS-negative, and 69 (67.0%) underwent first-line SR + CA. Higher relative densities of fibrin/platelets (0.56 vs 0.51; P < .001) and lower relative densities of erythrocytes (0.32 vs 0.42; P < .001) were observed in HAS/SVS-negative patients compared with HAS/SVS-positive patients. First-line SR + CA was associated with reduced odds of distal embolization (adjusted odds ratio, 0.18; 95% CI, 0.04–0.83; P = .027) and a more favorable 90-day functional outcome (adjusted odds ratio, 5.29; 95% CI, 1.06–26.34; P = .042) in HAS/SVS-negative patients and a longer recanalization time (53 vs 25 minutes; P = .025) and higher risk of subarachnoid hemorrhage (24.2% vs 0%; P = .044) in HAS/SVS-positive patients. ConclusionsAbsence of HAS/SVS may indicate a higher density of fibrin/platelets in the thrombus, and first-line SR + CA yielded superior functional outcomes than CA alone in patients with acute LVO without HAS/SVS.

Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification.

Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification. Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus. Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images. VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.

Dynamic Perviousness Predicts Revascularization Success in Acute Ischemic Stroke.

The predictive value of thrombus perviousness in acute ischemic stroke (AIS), as measured by computed tomography (CT), has been intensively studied with conflicting results. In this study, we investigate the predictive potential of the novel concept of dynamic perviousness using three-dimensional (3D) volumetric evaluation of occlusive thrombi. The full thrombus volume in 65 patients with a hyperdense artery sign on non-contrast CT (NCCT), who underwent mechanical thrombectomy (MT), was segmented. Perviousness maps were computed voxel-wise for the entire thrombus volume as thrombus attenuation increase (TAI) between NCCT and CT angiography (CTA) as well as between CTA and late venous phase CT (CTV). Perviousness was analyzed for its association with NIHSS at admission, Thrombolysis In Cerebral Infarction (TICI) score, and number of MT passes. The mean late-uptake TAI of thrombi with NIHSS scores greater than 21 at admission was approximately 100% higher than for lower scored NIHSS (p between 0.05 and 0.005). Concerning revascularization results, thrombi requiring less than four MT passes had ca. 80% higher group mean late-uptake TAI than clots requiring four or more passes (p = 0.03), and thrombi with TICI score III had ca. 95% higher group mean late-uptake TAI than thrombi with TICI II (p = 0.03). Standard perviousness showed no significant correlation with MT results. Standard thrombus perviousness of 3D clot volume is not associated with revascularization results in AIS. In contrast, dynamic perviousness assessed with a voxel-wise characterization of 3D thrombi volume may be a better predictor of MT outcomes than standard perviousness.

Detection of Hyperdense Arterial Sign in Acute Ischemic Stroke with Dual-Energy Computed Tomography: Optimal Combination with X-ray Energy and Slice Thickness.

The hyperdense artery sign (HAS) in acute ischemic stroke (AIS) is considered an important marker of a thrombus on computed tomography (CT). An advantage of scanning with dual-energy CT (DECT) is its ability to reconstruct CT images with various energies using the virtual monochromatic imaging (VMI) technique. The aim of this study was to investigate the optimal combination of X-ray energy and slice thickness to detect HASs on DECT. A total of 32 patients with confirmed occlusion of the horizontal (M1) portion of the middle cerebral artery were included in this study. Modified contrast-to-noise ratio (modified CNR) analysis was used as a method for evaluating HASs in AIS. A region of interest (ROI) was set as an HAS, the M1 portion, and an approximately 2 cm diameter ROI was set as the background including the HAS and measured. CT images with X-ray energies from 40 to 190 keV, with increments of 10 keV, were reconstructed based on VMI with 1, 2, and 3 mm slice thicknesses. The top five combinations of X-ray energy and slice thickness in descending order of the mean HAS-modified CNR were as follows: Rank 1, 60 keV-1 mm; Rank 2, 70 keV-1 mm; Rank 3, 60 keV-2 mm; Rank 4, 80 keV-2 mm; Rank 5, 60 keV-3 mm. Our study showed that the optimal combination to detect an HAS was 60 keV and a 1 mm slice thickness on DECT.

Development and internal-external validation of the ATHE Scale: predicting acute large vessel occlusion due to underlying intracranial atherosclerosis prior to endovascular treatment.

The diagnosis of intracranial atherosclerosis (ICAS) associated with large vessel occlusion (LVO) before endovascular treatment (EVT) remains a clinical challenge. This study was aimed at developing a predictive model for ICAS-LVO in the anterior circulation preceding EVT. Patients from two national stroke centers who had undergone EVT for acute ischemic stroke in the anterior circulation were evaluated. Those from one center served as the derivation cohort, whereas patients from another center functioned as the external validation cohort. ICAS-LVO was characterized as stenosis exceeding 70% or stenosis surpassing 50% accompanied by distal blood flow disruption or recurrent occlusion evidence during the intervention. A random forest algorithm helped to identify key predictors within the derivation cohort. Utilizing these predictors, the authors formulated a logistic regression model from the derivation cohort data, and the model was then internally validated through a bootstrapping method. Subsequently, a predictive score based on this model was constructed and evaluated in both cohorts. Among all the patients, 470 from the derivation cohort and 147 from the external validation cohort met the inclusion criteria. After random forest regression, the key predictors of ICAS-LVO included the absence of atrial fibrillation, the presence of truncal-type occlusion, the absence of a hyperdense artery sign, and a lower baseline examination National Institutes of Health Stroke Scale (NIHSS) score (ATHE Scale). Incorporating these variables into the logistic regression model yielded an area under the curve (AUC) of 0.920 (95% CI 0.894-0.947) for ICAS-LVO prediction. After bootstrapping validation, the model produced a mean AUC of 0.915. Subsequently, the ATHE score, derived from these predictors, registered an AUC of 0.916 (95% CI 0.887-0.939, p < 0.001) in the derivation cohort and 0.890 (95% CI 0.828-0.936, p < 0.001) in the external validation cohort. The ATHE Scale, incorporating atrial fibrillation, truncal-type occlusion, hyperdense artery sign, and baseline examination NIHSS score, is an accurate, objective tool for predicting ICAS-LVO prior to EVT.

Leukoaraiosis and stroke severity scores in post-rtPA intracerebral haemorrhage

IntroductionPost thrombolytic symptomatic intracerebral haemorrhage (sICH) is a major concern in patients who had acute ischaemic stroke. Leukoaraiosis (LA) is reported to be related with sICH after intravenous thrombolytic treatment....

Automated Intracranial Clot Detection: A Promising Tool for Vascular Occlusion Detection in Non-Enhanced CT.

(1) Background: to test the diagnostic performance of a fully convolutional neural network-based software prototype for clot detection in intracranial arteries using non-enhanced computed tomography (NECT) imaging data. (2) Methods: we retrospectively identified 85 patients with stroke imaging and one intracranial vessel occlusion. An automated clot detection prototype computed clot location, clot length, and clot volume in NECT scans. Clot detection rates were compared to the visual assessment of the hyperdense artery sign by two neuroradiologists. CT angiography (CTA) was used as the ground truth. Additionally, NIHSS, ASPECTS, type of therapy, and TOAST were registered to assess the relationship between clinical parameters, image results, and chosen therapy. (3) Results: the overall detection rate of the software was 66%, while the human readers had lower rates of 46% and 24%, respectively. Clot detection rates of the automated software were best in the proximal middle cerebral artery (MCA) and the intracranial carotid artery (ICA) with 88-92% followed by the more distal MCA and basilar artery with 67-69%. There was a high correlation between greater clot length and interventional thrombectomy and between smaller clot length and rather conservative treatment. (4) Conclusions: the automated clot detection prototype has the potential to detect intracranial arterial thromboembolism in NECT images, particularly in the ICA and MCA. Thus, it could support radiologists in emergency settings to speed up the diagnosis of acute ischemic stroke, especially in settings where CTA is not available.

Textural Analysis of the Hyperdense Artery Sign in Patients with Acute Ischemic Stroke Predicts the Outcome of Thrombectomy.

Textural analysis is pivotal in augmenting the diagnosis and outcomes of endovascular procedures for stroke patients. Due to the detection of changes imperceptible to the human eye, this type of analysis can potentially aid in deciding the optimal type of endovascular treatment. We included 40 patients who suffered from acute ischemic stroke caused by large vessel occlusion, and calculated 130 different textural features based on the non-enhanced CT scan using an open-source software (3D Slicer). Using chi-squared and Mann-Whitney tests and receiver operating characteristics analysis, we identified a total of 21 different textural parameters capable of predicting the outcome of thrombectomy (quantified as the mTICI score), with variable sensitivity (50-97.9%) and specificity (64.6-99.4%) rates. In conclusion, CT-based radiomics features are potential factors that can predict the outcome of thrombectomy in patients suffering from acute ischemic stroke, aiding in the decision between aspiration, mechanical, or combined thrombectomy procedure.

Diagnostic Accuracy of Hyperdense Artery Sign in Early Detection of Middle Cerebral Artery Infarction: A Cross-Sectional Validation Study

Background Hyperdense middle cerebral artery sign (HMCAS) on a non-enhanced multidetector computed tomography (MDCT) scan is considered an important radiological marker in detecting acute arterial thrombotic occlusion, and it is one of the earliest signs of ischemic cerebrovascular accident (CVA). This finding has been observed within 90 min of symptom onset. Modern approaches to patients with cerebral infarction emphasize early diagnosis and management. Purpose To determine the diagnostic accuracy of hyperdense artery signs in early detection of middle cerebral artery (MCA) infarction on non-contrast-enhanced MDCT scan using Magnetic Resonance Angiography (MRA) within 24 h as the gold standard for definitive diagnosis. Method A total of 140 patients aged 35–70 years, referred to the radiology department of Aga Khan University Hospital with clinical suspicion of acute cerebral infarction, were included. After clinical suspicion of acute infarction, the patient underwent an initial complete MDCT scan of the brain, which was performed using Aquilion ONE 640 slice MDCT (Toshiba Medical Systems, Japan). Consultant radiologists, with a minimum of 5 years of experience in MDCT brain imaging, interpreted the images. Follow-up examination with MRA within 24 h was performed to confirm the diagnosis of MCA infarction. Results Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of HMCAS in the early detection of MCA infarction on non-contrast-enhanced MDCT scan using MRA as the gold standard for definitive diagnosis was 96.20%, 93.44%, 95.0%, 95.0%, and 95.0%, respectively. Conclusion This study concluded that the diagnostic accuracy of hyperdense artery signs in the early detection of MCA infarction on non-contrast-enhanced MDCT scans is very high.

MR microscopy to assess clot composition following mechanical thrombectomy predicts recanalization and clinical outcome

BackgroundMechanical thrombectomy (MT) is the standard of care for patients with a stroke and large vessel occlusion. Clot composition is not routinely assessed in clinical practice as no specific diagnostic...

Improvement of diagnostic performance of hyperacute ischemic stroke in head CT using an image-based noise reduction technique with non-black-boxed process

PurposeThis study aims to investigate whether an image-based noise reduction (INR) technique with a conventional rule-based algorithm involving no black-boxed processes can outperform an existing hybrid-type iterative reconstruction (HIR) technique, when applied to brain CT images for diagnosis of early CT signs, which generally exhibit low-contrast lesions that are difficult to detect. MethodsThe subjects comprised 27 patients having infarctions within 4.5 h of onset and 27 patients with no change in brain parenchyma. Images with thicknesses of 5 mm and 0.625 mm were reconstructed by HIR. Images with a thickness of 0.625 mm reconstructed by filter back projection (FBP) were processed by INR. The contrast-to-noise ratios (CNRs) were calculated between gray and white matters; lentiform nucleus and internal capsule; infarcted and non-infarcted areas. Two radiologists subjectively evaluated the presence of hyperdense artery signs (HASs) and infarctions and visually scored three properties regarding image quality (0.625-mm HIR images were excluded because of their notably worse noise appearances). ResultsThe CNRs of INR were significantly better than those of HIR with P < 0.001 for all the indicators. INR yielded significantly higher areas under the curve for both infarction and HAS detections than HIR (P < 0.001). Also, INR significantly improved the visual scores of all the three indicators. ConclusionThe INR incorporating a simple and reproducible algorithm was more effective than HIR in detecting early CT signs and can be potentially applied to CT images from a large variety of CT systems.

Impact of vessel tortuosity and radiological thrombus characteristics on the choice of first-line thrombectomy strategy: Results from the ESCAPE-NA1 trial.

Despite improvements in device technology, only one-third of stroke patients undergoing endovascular thrombectomy (EVT) achieve first-pass effect (FPE). We investigated the effect of arterial tortuosity and thrombus characteristics on the relationship between first-line EVT strategy and angiographic outcomes. Patients with thin-slice baseline CT-angiography from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of acute ischemic stroke) were included. Tortuosity was estimated using the tortuosity index extracted from catheter pathway, and radiological thrombus characteristics were length, non-contrast density, perviousness and hyperdense artery sign. We assessed the association of first-line EVT strategy (stent-retriever [SR] versus contact aspiration [CA] versus combined SR+CA) with FPE (eTICI score 2c/3 after one pass), final eTICI 2b/3, number of passes and procedure duration using multivariable regression. Interaction of tortuosity and thrombus characteristics with first-line technique were assessed using interaction terms. Among 520 included patients, SR as a first-line modality was used in 165 (31.7%) patients, CA in 132 (25.4%), and combined SR+CA in 223 (42.9%). FPE was observed in 166 patients (31.9%). First-line strategy was not associated with FPE. Tortuosity had a significant effect on FPE only in the CA group (aOR = 0.90 [95% CI 0.83-0.98]) compared with stent-retrievers and combined first-line approach (p interaction = 0.03). There was an interaction between thrombus length and first-line strategy for number of passes (p interaction = 0.04). Longer thrombi were associated with higher number of passes only in the CA group (acOR 1.03 [95% CI 1.00-1.06]). Our study suggests that vessel tortuosity and longer thrombi may negatively affect the performance of first-line contact aspiration catheters in acute stroke patients undergoing EVT.

Abstract TP88: Deep Learning-based Automatic Detection And Segmentation Of Hyperdense Artery Sign On Non-contrast Computed Tomography In Acute Ischemic Stroke

Introduction: CT- or MR-angiography(CTA/MRA) is the golden-standard to evaluate the site of large vessel occlusion (LVO). However, there are cases in which occluded vessels can be recognized as a hyperdense artery sign (HAS) on non-contrast CT (NCCT). If the HAS is detectable from NCCT, it may lead to a significant reduction in the time to start treatment. In this study, we developed and validated the deep learning model to detect the HAS on NCCT. Methods: This study used three multicenter retrospective datasets; ischemic stroke patients with LVO (occlusions of the intracranial internal carotid artery (ICA) and middle cerebral artery M1/M2 segments) who underwent mechanical thrombectomy, ischemic stroke patients without LVO, non-stroke patients. For developing the deep neural network model, positive samples (182 ICA/M1 and 57 M2 occlusion patients) were selected from stroke patients with LVO wherein the HAS was visible on NCCT. The decision for HAS visibility was made by two Neuro-interventionalists who referred to paired MRA/CTA of the same patient. While doing so, they also manually labeled the HAS regions on NCCT. Negative samples (592 patients) were collected from stroke patients without LVO and non-stroke patients. We split the data into training, validation and test sets. After we trained and validated the model, its performance was evaluated on the test set. The performance was measured using the metrics of sensitivity and specificity. Results: The sensitivity of the model was 0.78 (49/63) for ICA/M1 and 0.77 (10/13) for M2 occlusion patients. The specificity of the model was 0.61 (33/54) for stroke patients without LVO and non-stroke patients. Conclusions: The performance of our deep learning-based method to automatically detect the HAS on NCCT is close to that of expert physicians reported in earlier studies, and our method may lead to further improvement of patient prognosis by shortening the time to start treatment.

Distal Embolization in Relation to Radiological Thrombus Characteristics, Treatment Details, and Functional Outcome.

Distal embolization (DE) is a common complication of endovascular treatment (EVT). We investigated the association of radiological thrombus characteristics and treatment details with DE. Patients with thin-slice (≤2.5 mm) baseline noncontrast computed tomography and computed tomography angiography from the ESCAPE-NA1 trial (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke) were included. Thrombus annotation was performed manually on coregistered scans by experienced readers. We assessed thrombus location, distance from internal carotid artery terminus, length, perviousness, absolute attenuation, and hyperdense artery sign. In addition, we evaluated balloon guide catheter use during EVT, first-line EVT approach, the number of thrombectomy passes, and prior intravenous thrombolysis administration. DE was defined as the occurrence of emboli distal to the target artery or in new territories during EVT. The association between thrombus characteristics, treatment details, and DE was evaluated using descriptive statistics and multivariable mixed-effects logistic regression, resulting in adjusted odds ratios (aOR) with 95% CI. Interaction between IVT and radiological thrombus characteristics was assessed by adding interaction terms in separate models. In total, 496 out of 1105 (44.9%) ESCAPE-NA1 patients were included. DE was detected in 251 out of 496 patients (50.6%). Patients with DE had longer thrombi (median, 28.5 [interquartile range, 20.8-42.3] mm versus 24.4 [interquartile range, 17.1-32.4] mm; P<0.01). There were no statistically significant differences in the other thrombus characteristics. Factors associated with DE were thrombus length (aOR, 1.02 [95% CI, 1.01-1.04]), balloon guide catheter use (aOR, 0.49 [95% CI, 0.29-0.85]), and number of passes (aOR, 1.24 [95% CI, 1.04-1.47]). In patients with hyperdense artery sign, IVT was associated with reduced odds of DE (aOR, 0.55 [95% CI, 0.31-0.97]), P for interaction=0.04. DE was associated with longer thrombi, no balloon guide catheter use, and more EVT passes. IVT was associated with a reduced risk of DE in patients with hyperdense artery sign. These findings may support treatment decisions on IVT and EVT approaches.

Cerebral Edema in Patients with severe Hemispheric Syndrome: Incidence, Risk Factors, and Outcomes-Data from SITS-ISTR.

Cerebral edema (CED) in ischemic stroke can worsen prognosis and about 70% of patients who develop severe CED die if treated conservatively. We aimed to describe incidence, risk factors and outcomes of CED in patients with extensive ischemia. Oservational study based on Safe Implementation of Treatments in Stroke-International Stroke Treatment Registry (2003-2019). Severe hemispheric syndrome (SHS) at baseline and persistent SHS (pSHS) at 24 hours were defined as National Institutes of Health Stroke Score (NIHSS) >15. Outcomes were moderate/severe CED detected by neuroimaging, functional independence (modified Rankin Scale 0-2) and death at 90 days. Patients (n=8,560) presented with SHS and developed pSHS at 24 hours; 82.2% received intravenous thrombolysis (IVT), 10.5% IVT+thrombectomy, and 7.3% thrombectomy alone. Median age was 77 and NIHSS 21. Of 7,949 patients with CED data, 3,780 (47.6%) had any CED and 2,297 (28.9%) moderate/severe CED. In the multivariable analysis, age <50 years (relative risk [RR], 1.56), signs of acute infarct (RR, 1.29), hyperdense artery sign (RR, 1.39), blood glucose >128.5 mg/dL (RR, 1.21), and decreased level of consciousness (RR, 1.14) were associated with moderate/severe CED (for all P<0.05). Patients with moderate/severe CED had lower odds to achieve functional Independence (adjusted odds ratio [aOR], 0.35; 95% confidence interval [CI], 0.23 to 0.55) and higher odds of death at 90 days (aOR, 2.54; 95% CI, 2.14 to 3.02). In patients with extensive ischemia, the most important predictors for moderate/ severe CED were age <50, high blood glucose, signs of acute infarct, hyperdense artery on baseline scans, and decreased level of consciousness. CED was associated with worse functional outcome and a higher risk of death at 3 months.

Identifying large vessel occlusion using the hyperdense artery sign in patients treated with mechanical thrombectomy

ObjectivesThe hyperdense artery sign on non-contrast computed tomography-reconstructed images is useful for identifying large vessel occlusion in acute ischemic stroke. This study aimed to assess its efficacy in patients with large vessel occlusion treated with mechanical thrombectomy. Materials and methods: This retrospective and prospective single-centered study from June 2019 to May 2021 evaluated the use of non-contrast computed tomography-reconstructed images for detecting hyperdense artery sign to identify large vessel occlusion from June 2020 to May 2021. We registered consecutive potential candidates for mechanical thrombectomy due to suspected stroke and assessed the accuracy of hyperdense artery sign on non-contrast computed tomography-reconstructed images for large vessel occlusion in the hyperacute setting. Non-contrast computed tomography images were reconstructed into maximum intensity projection images with iterative reconstruction algorithms to detect hyperdense artery signs. We compared the door-to-puncture time and functional outcome at 90 days before and after employing non-contrast computed tomography-reconstructed images in patients with large vessel occlusion treated with mechanical thrombectomy. ResultsThe cohort included 82 patients, wherein 47 were treated with mechanical thrombectomy. The sensitivity (96%) and specificity (94%) of hyperdense artery sign on non-contrast computed tomography-reconstructed images for large vessel occlusion were performed. The door-to-puncture time was significantly shortened after using non-contrast computed tomography-reconstructed images (49 versus 28 min, p = 0.001), but the functional outcome at 90 days remained unchanged. ConclusionsNon-contrast computed tomography-reconstructed images, as a vascular imaging tool for mechanical thrombectomy, can reduce workflow time in hospitals by identifying large vessel occlusion with high sensitivity and specificity.

Early diagnosis of intracranial atherosclerotic large vascular occlusion: A prediction model based on DIRECT-MT data.

This study aimed to build a prediction model to early diagnose intracranial atherosclerosis (ICAS)-related large vascular occlusion (LVO) in acute ischemic stroke patients before digital subtractive angiography. Patients enrolled in the DIRECT-MT trial (NCT03469206) were included in our secondary analysis and distributed into ICAS-LVO and non-ICAS-LVO groups. We also retrieved demographic data, medical histories, clinical characteristics, and pre-operative imaging data. Hypothesis testing was used to compare data of the two groups, and univariate logistic regression was used to identify the predictors of ICAS-LVO primarily. Then, we used multivariate logistic regression to determine the independent predictors and formulate the prediction model. Model efficacy was estimated by the area under the receiver operating characteristic (ROC) curve (AUC) and diagnostic parameters generated from internal and external validations. The subgroup analysis included 45 cases in the ICAS-LVO group and 611 cases in the non-ICAS-LVO group. Variates with p < 0.1 in the comparative analysis were used as inputs in the univariate logistic regression. Next, variates with p < 0.1 in the univariate logistic regression were used as inputs in the multivariate logistic regression. The multivariate logistic regression indicated that the atrial fibrillation history, hypertension and smoking, occlusion located at the proximal M1 and M2, hyperdense artery sign, and clot burden score were related to the diagnosis of ICAS-LVO. Then, we constructed a prediction model based on multivariate logistics regression. The sensitivity and specificity of the model were 84.09 and 74.54% in internal validation and 73.11 and 71.53% in external validation. Our current prediction model based on clinical data of patients from the DIRECT-MT trial might be a promising tool for predicting ICAS-LVO.

Is it possible to predict the outcome of endovascular thrombectomy for hyperdense middle cerebral artery sign at the time of first admission?

The hyperdense middle cerebral artery sign (HMCAS) on admission non-contrast computed tomography (NCCT) is a well-characterized phenomenon in acute ischemic stroke. The purpose of this study is to determine the impact of HMCAS on the outcome of patients who underwent endovascular thrombectomy. A retrospective analysis of a prospectively collective database included 136 consecutive patients with anterior circulation acute ischemic stroke who underwent endovascular thrombectomy. We collected the demographics, and clinical and brain imaging as well as functional and imaging outcomes data at baseline. Patients were divided into two groups with hyperdense artery sign and those without the sign. The difference between the two groups in terms of mortality and prognosis was analyzed. There were 136 patients, 50.7% of them were women. The mean age was 59.1 years. The subgroup with HMCAS present consisted of 93 patients. There were no differences in demographics and clinical characteristics between the two groups; however, tobacco use is more common in patients with HMCAS. No significant difference was observed in clinical outcomes and mortality between the two groups at 3 months. Patients with HMCAS had statistically more new territory emboli during the procedure (9.7%) compared to patients without HMCAS. We showed that the presence of HMCAS in initial CT was not helpful in predicting good clinical outcomes in patients undergoing endovascular therapy patients. However, the presence of HMCAS is related to more new territory embolism during the procedure. Different endovascular strategies may be applied to these patients.

"Too Beautiful" Sylvan Artery

Despite the advent and increasing availability of magnetic resonance imaging, the imaging modality of choice in the acute care of stroke patients in many institutions remains CT. The hyperdense artery sign is the primary marker of acute ischaemic stroke. We report the case of a 70-year-old patient, in whom brain CT without contrast injection performed́ in emergency following a neurological deficit, allowed the objectification of an early ischemic stroke.