Major Intracranial Arteries Research Articles

Role of Susceptibility Weighted Imaging (SWI) in Comparison to Magnetic Resonance Angiography in Assessment of the Intra-Arterial Thrombus in Patients with Acute Ischemic Stroke

Abstract Background Stroke occurs when the blood supply to the brain is cut off, usually due to a blood vessel burst or being blocked by a clot. This reduces the supply of oxygen and nutrients, causing brain tissue damage. The effects of a stroke depend on which part of the brain is injured. For this purpose, thrombus assessment in patients with acute stroke is of major clinical relevance since the location of the thrombus may determine the therapeutic decision. Aim of the Work Aim of study is to assess the role of susceptibility weighted imaging in assessment of intra-arterial thrombus in correlation with MRA and basic stroke protocol in patients with acute ischemic stroke. Patients and Methods This study is a cross-sectional study was conducted at Ain Shams University Hospitals at Radiology department. Our study included thirty patients with acute stroke symptoms in less than 24 hours of symptoms onset. The main source of data for this study was the prospectively conducted scans and clinical history of the patients referred to the MRI section of the department of Radiology, Ain Shams University Hospitals for doing MRI stroke protocol with addition of SWI sequence from November 2022 to June 2023. Results Thirty patients complaining of acute stroke symptoms in less than 24 hours of symptoms onset. Every single one of them went through MRI stroke protocol assessment and SWI sequence was added. So, SVS and TOF MRA were able to detect intra-arterial thrombus in acute stroke patients by 90 % and 95 %, respectively. There was no statistically significant difference in the rates of detection of intra-arterial thrombosis by SWI and MRA in patients with acute ischemic stroke (P = 0.57). The sensitivity of SWI for detection the intra-arterial thrombus in relation to MRA in MCA is 90%, in ACA and PCA is 100%, ICA is 66.7%. While specificity of SWI in relation to MRA in MCA is 80%, in PCA, ACA and ICA are 100%. The accuracy of SWI in assessment of intra-arterial thrombus in comparison to MRA in MCA is 94%, PCA 100%, ICA 95% and ACA 100%. The length of thrombus in SWI (lengthof SVS) could be measured ranging between 0.5-3.5 cm. Conclusion The SWI sequence needs to be incorporated into SWI stroke protocol for evaluating patients who have recently suffered an acute stroke as MRA and SWI techniques complement each other for visual detection of the occluded vessel. SWI has reasonable sensitivity, specificity and accuracy in the assessment of intra-arterial thrombosis in relation to MRA in patient of acute ischemic stroke. The „susceptibility sign' has a high sensitivity for diagnosing acute intracranial vascular blockage location and its extent in all major intracranial arteries. Also, it can be used in measuring the length of the intra-arterial thrombus over TOF MRA which cannot entirely demarcate thrombus length.

The Correlation between Doppler Assessment of Cerebral Blood Flow Changes and Common Neonatal Intracranial Lesions

Abstract Background Transcranial ultrasonography, in experienced hands, is an outstanding tool to detect brain abnormalities in preterm and full-term infants, and to follow the progression of these lesions. Doppler sonography is an excellent modality for assessment of the cerebral vasculature in the newborn and provides valuable information about cerebral vascular anatomy. Aim and Objectives to discuss the value added by transcranial Doppler assessment of blood flow in major intracranial cerebral arteries to brain status evaluation in neonatal intracranial hemorrhagic and ischemic conditions by employing Doppler techniques. Subjects and Methods This was a prospective cohort study that was carried out at tertiary care centers.45 neonates admitted to the neonatal intensive care unit were enrolled based on having the clinical diagnosis of perinatal asphyxia and having ischemic and hemorrhagic cerebral changes on grey scale sonographic evaluation. Doppler interrogation of both anterior cerebral artery (ACA) and middle cerebral artery (MCA) was performed bilaterally. Follow up evaluation was performed upon discharge. It was conducted from October 2022 to April 2023. Results There was a statistically significant difference between the studied groups as regard (APGAR Score at 1 min and 5 min), (peak systolic velocity (PSV) (cm/s) of ACA and resistive index (RI)), (peak systolic velocity (PSV) (cm/s) of MCA and resistive index (RI)), Correlation between Severity of hemorrhagic and ischemic cerebral changes with other studied Parameters except in gestational age and body weight. Conclusion Ultrasonographic features and cerebral blood flow parameters are useful for the early diagnosis of hypoxic-ischemic encephalopathy and help predict outcome. In the presence of more extensive hypoxic-ischemic brain injury and statistically significantly lower peak systolic velocity and higher resistive index in the anterior and medial cerebral arteries, the outcomes were poorer.

Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease.

It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD. We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses. A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92. Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.

Higher cerebral blood flow on four-dimensional flow magnetic resonance imaging in young women.

We investigated the reduction in regional brain volume and cerebral blood flow (CBF) with aging and explored potential sex differences in healthy brains. Three-dimensional (3D) T1-weighted magnetic resonance imaging (MRI), time-of-flight magnetic resonance angiography, and four-dimensional (4D) flow MRI were performed on 129 healthy volunteers aged 22-92 years. The brains of healthy volunteers were segmented into 21 subregions using 3D T1-weighted MRI and CBFs in 16 major intracranial arteries were measured using 4D flow MRI. The cortical gray matter volume decreased linearly with aging, whereas the cerebral white matter volume increased until the 40s and then decreased, and the subcortical gray matter volume changed little with aging. The cortical gray matter volume was significantly associated with the total CBF of the major intracranial arteries distal to the circle of Willis; however, the cerebral white matter and subcortical gray matter volumes were not. Generally, women have higher total CBF than men, particularly in their 40s and younger, despite the smaller intracranial volume and smaller diameters of intracranial arteries than men. This may contribute to the higher incidence of subarachnoid hemorrhage due to cerebral aneurysms and migraine in women.

Dietary oily fish intake is inversely associated with moderate-to-severe intracranial artery stenosis in older adults of indigenous Ecuadorian ancestry

Background and aimsInformation on the association between dietary oily fish intake and intracranial atherosclerosis is limited and contradictory. Inconsistencies might be in part related to heterogeneous designs and differences in race/ethnicity of study populations. We aim to assess whether oily fish intake is inversely associated with intracranial artery stenosis (ICAS) in frequent fish consumers of indigenous ancestry living in coastal Ecuador. MethodsThe study included 384 participants aged ≥60 years enrolled in the Atahualpa Project Cohort. Dietary oily fish intake was quantified systematically via validated surveys and all participants received a time-of-flight MRA of intracranial vessels. Poisson regression models, adjusted for demographics, level of education, traditional risk factors and severe tooth loss, were fitted to assess the association between amounts of oily fish intake and the number of intracranial arteries with moderate-to-severe (≥50 %) stenosis. ResultsParticipants had a mean age of 67.7 ± 7 years, and 56 % were women. The mean oily fish intake was 8.9 ± 5.2 servings/week; 283 (74 %) participants consumed ≥5.2 servings/week (2nd to 4th quartiles of fish intake). Forty-three (11 %) participants had at least one major intracranial artery with moderate-to-severe stenosis. Both univariate and multivariate models showed a significant inverse association between consumption of oily fish in the 2nd to 4th quartiles and ≥50 % stenosis in at least one artery (β: 0.46; 95 % C.I.: 0.27–077, and β: 0.52; 95 % C.I.: 0.30–0.90, respectively). ConclusionsConsumption of more than five oily fish servings/week is associated with lower prevalence of moderate-to-severe ICAS in indigenous Ecuadorians.

Differential sensitivities to blood pressure variations in internal carotid and intracranial arteries: a numerical approach to stroke prediction

Stroke remains a global health concern, necessitating early prediction for effective management. Atherosclerosis-induced internal carotid and intra cranial stenosis contributes significantly to stroke risk. This study explores the relationship between blood pressure and stroke prediction, focusing on internal carotid artery (ICA) branches: middle cerebral artery (MCA), anterior cerebral artery (ACA), and their role in hemodynamics. Computational fluid dynamics (CFD) informed by the Windkessel model were employed to simulate patient-specific ICA models with introduced stenosis. Central to our investigation is the impact of stenosis on blood pressure, flow velocity, and flow rate across these branches, incorporating Fractional Flow Reserve (FFR) analysis. Results highlight differential sensitivities to blood pressure variations, with M1 branch showing high sensitivity, ACA moderate, and M2 minimal. Comparing blood pressure fluctuations between ICA and MCA revealed heightened sensitivity to potential reverse flow compared to ICA and ACA comparisons, emphasizing MCA's role. Blood flow adjustments due to stenosis demonstrated intricate compensatory mechanisms. FFR emerged as a robust predictor of stenosis severity, particularly in the M2 branch. In conclusion, this study provides comprehensive insights into hemodynamic complexities within major intracranial arteries, elucidating the significance of blood pressure variations, flow attributes, and FFR in stenosis contexts. Subject-specific data integration enhances model reliability, aiding stroke risk assessment and advancing cerebrovascular disease understanding.

A Case of Multiple Intracranial Major Artery Stenoses With Coexisting PCSK9 p.E32K and RNF213 p.R4810K Variants.

Familial hypercholesterolemia (FH), caused by PCSK9 p.E32K, is characterized by early-onset coronary artery disease. However, the relationship between PCSK9 p.E32K and cerebrovascular disease is unclear. One of our patients with the PCSK9 p.E32K had several intracranial artery stenoses (ICAS). The objective of this case series was to identify factors that may be associated with ICAS in the variant carriers. A 75-year-old Japanese woman with FH carrying PCSK9 p.E32K was found to have 5 asymptomatic ICAS when brain magnetic resonance angiography (MRA) was performed. We retrospectively investigated additional patients with FH who underwent brain MRA at our institution to explore the unknown factors accelerating ICAS. We investigated an additional 5 patients with FH who underwent brain MRA. Of them, only one had mild ICAS. The RNF213 p.R4810K that is an established genetic risk for ICAS, particularly in East Asians, was identified only in the patient with 5 ICAS. PCSK9 and RNF213 play an important role in lipid metabolism and endothelial integrity. Therefore, together, these variants could be involved in the development of multiple ICAS. Our case series indicated that PCSK9 p.E32K carriers should undergo early brain screening to obtain appropriate stroke prevention measures in the asymptomatic stage.

Mediterranean-style diet and intracranial large artery stenosis in the Northern Manhattan Study

ObjectivesGiven Mediterranean-style diet (MeDi) reduces risk of cardiovascular events, we hypothesized MeDi may also be protective against intracranial large artery stenosis (ICAS), a common cause of stroke worldwide. MethodsThis cross-sectional study included stroke-free participants of the Northern Manhattan Study, a diverse population-based study of stroke risk factors. We represented MeDi continuously (range 0-8) based on enrollment food frequency questionnaires, excluding alcohol consumption. We evaluated ICAS both dichotomously at clinically relevant stenosis severities and continuously as a score (possible range 0-44), summated from stenosis severity scores of major intracranial arteries from time-of-flight magnetic resonance angiography. We used logistic or zero-inflated Poisson regression, adjusting for key confounders. ResultsAmong 912 included participants (mean age 64±8 years, 59% female, 65% Hispanic, mean MeDi score 4±1.5), 5% and 8% of participants had ≥50% or ≥70% ICAS, respectively (score median [interquartile range]: 0 [0-2]). Increased MeDi score was inversely associated with ICAS, but did not reach statistical significance (≥50% stenosis odds ratio (OR) [95% confidence interval (CI)]: 0.89 [0.79-1.06]; ≥70% stenosis OR [95% CI]: 0.91 [0.74-1.13]; stenosis score β-estimate [95% CI]: -0.02 [-0.06-0.01]). ConclusionIn this stroke-free subsample, we did not find a significant association between MeDi and ICAS. We may have been limited by statistical power.

Amplified Risk of Intracranial Artery Stenosis/Occlusion Associated With RNF213 p.R4810K in Familial Hypercholesterolemia

BackgroundThe RNF213 p.R4810K variant is associated with moyamoya disease in East Asian individuals and increases the risk of developing intracranial major artery stenosis/occlusion (ICASO) that affects anterior circulation. Meanwhile, 0.5% to 2.5% of asymptomatic East Asian individuals also carry this variant. As such, additional factors are likely required to develop ICASO in variant carriers. Familial hypercholesterolemia (FH) is a common genetic disorder in Japan that has a significant associated risk of developing premature coronary atherosclerosis; however, the relationship between ICASO and FH remains unknown. ObjectivesThis study aimed to determine if FH facilitates RNF213 p.R4810K carriers to develop ICASO. MethodsWe enrolled patients with FH who had undergone brain magnetic resonance angiography at our hospital from May 2005 to March 2020. The RNF213 p.R4810K variant, and LDLR and PCSK9 mutations were genotyped. ICASO lesions in the brain magnetic resonance angiogram were analyzed. ResultsSix RNF213 p.R4810K variant carriers were identified among 167 patients with FH (LDLR, n = 104; PCSK9, n = 22). Five of the carriers (83.3%) exhibited ICASO in the anterior circulation; a significant difference in ICASO frequency was observed between the variant carriers and noncarriers (P = 0.025). The median number of stenotic or occluded arteries in the anterior circulation was also significantly larger in the variant carriers (3 vs 1, P = 0.01); however, did not differ between patients with FH with LDLR and PCSK9 mutations. ConclusionsPatients with FH exhibit increased prevalence and severity of ICASO associated with RNF213 p.R4810K. Gene mutations for FH may confer an increased risk of ICASO in RNF213 p.R4810K carriers.

Balloon Angioplasty for Symptomatic Intracranial Artery Stenosis (BASIS): protocol of a prospective, multicentre, randomised, controlled trial

BackgroundThe superiority of balloon angioplasty plus aggressive medical management (AMM) to AMM alone for symptomatic intracranial artery stenosis (sICAS) on efficacy and safety profiles still lacks evidence from randomised controlled...

Abstract WMP79: Stroke Risk Prediction In Symptomatic Anterior Circulation ICAS: Post Hoc Analysis Of Regional QMRA Flow From The MYRIAD Study

Introduction: Intracranial atherosclerotic disease (ICAD) remains a major source of stroke worldwide, with high recurrence risk. Prior evaluation of posterior circulation ICAD patients enrolled in the prospective VERiTAS and MYRIAD studies revealed regional hypoperfusion, assessed by large vessel flow measurements using quantitative MRA (QMRA), predicts subsequent vertebrobasilar stroke risk. We examined whether a similar approach to regional flow assessment using QMRA predicted stroke risk in anterior circulation ICAD patients enrolled in MYRIAD. Methods: MYRIAD enrolled patients with recent TIA or stroke attributable to 50-99% stenosis of proximal intracranial artery; the primary outcome was ischemic stroke in the territory of the stenotic artery with 1 year of follow-up. Secondary outcomes included new in-territory infarcts on MRI at 6-8 weeks. Flow was measured in the major intracranial arteries at baseline using QMRA. We designated patients as low- or normal-flow status based on an algorithm assessing distal flow and collateral capacity using age-normalized MCA and hemispheric (aggregate of ipsilateral ACA, MCA, and PCA) flows. Different thresholds for flow status categorization were tested to determine the optimal algorithm for stroke risk prediction. Results: Of 73 enrolled subjects with symptomatic anterior circulation ICAD, 7 (9.6%) patients had recurrent stroke. Z-score thresholds for age-normalized flow ranging from -0.5 to -1.5 were examined. The optimal thresholds identified were as follows: -1 for the MCA and -0.75 for hemispheric flow. 24 (33%) patients were categorized as low-flow status based on these thresholds; recurrent stroke occurred in 21% of low-flow patients vs. 4% of normal-flow patients (OR 6.2 (95% CI 1.1-34.7, p=0.04). However, flow status was not predictive of recurrent infarct on imaging among 61 patients with 6-8 week MRI (32% in low-flow vs. 26% in normal-flow patients). Conclusions: Similar to the predictive value in the posterior circulation, distal flow status assessed through QMRA regional flow measurement appears to be predictive for recurrent clinical (but not imaging-based) stroke. Identification of high-risk patients has implications for future investigation of therapeutic interventions.

Rationale and design of a randomised double-blind 2×2 factorial trial comparing the effect of a 3-month intensive statin and antiplatelet therapy for patients with acute mild ischaemic stroke or high-risk TIA with intracranial or extracranial atherosclerosis (INSPIRES)

BackgroundIt remains unclear if intensive antiplatelet and statin treatments begun within 24–72 hours of cerebral ischaemic events from intracranial or extracranial atherosclerosis is effective or safe.MethodsThe Intensive Statin and Antiplatelet...

Elevated RANTES levels are associated with increased risk of cerebral atherosclerotic stenosis

BackgroundCerebral atherosclerotic stenosis (CAS) is a significant factor in the development of acute ischemic stroke (AIS). Previous studies have reported that cytokines are involved in atherosclerotic diseases, although the relationship between serum levels of the chemokine RANTES (regulated on activation, normal T-cell expressed and secreted) and the presence of CAS remains unclear.MethodsIn total, 127 participants (65 non-AIS controls and 62 patients with AIS) were involved in this study. CAS was defined as the presence of ≥ 50% stenosis in major intracranial or extracranial artery by a Digital Substraction Angiography (DSA) examination, and we classified all participants into four groups according to stroke and CAS status. Serum concentrations of 8 cytokines, including RANTES, were measured by the Human ProcartaPlex Multiplex Immunoassay Kit.ResultsSeventy-eight participants (61.41%) had CAS, of which 39 cases with AIS and 39 case with non-AIS. Patients with CAS had higher RANTES levels compared to non-CAS patients in both the non-AIS group (10.54 ± 0.80 vs. 13.20 ± 0.71, p = 0.016) and stroke group (11.96 ± 0.87 vs. 15.03 ± 0.75, p = 0.011), and multivariate logistic regression analysis showed that the RANTES level is independently associated with CAS in both the non-AIS group (adjusted odds ratio (OR), 1.07; 95% CI, 1.02–1.12, P = 0.004) and stroke group (adjusted OR, 1.32; 95% CI, 1.10–1.58, P = 0.003).ConclusionPatients with CAS have higher levels of serum RANTES than non-CAS patients regardless of stroke status suggesting that RANTES may play an important role in the formation of CAS.

Transcranial Doppler analysis based on computer and artificial intelligence for acute cerebrovascular disease

Cerebrovascular disease refers to damage to brain tissue caused by impaired intracranial blood circulation. It usually presents clinically as an acute nonfatal event and is characterized by high morbidity, disability, and mortality. Transcranial Doppler (TCD) ultrasonography is a non-invasive method for the diagnosis of cerebrovascular disease that uses the Doppler effect to detect the hemodynamic and physiological parameters of the major intracranial basilar arteries. It can provide important hemodynamic information that cannot be measured by other diagnostic imaging techniques for cerebrovascular disease. And the result parameters of TCD ultrasonography such as blood flow velocity and beat index can reflect the type of cerebrovascular disease and serve as a basis to assist physicians in the treatment of cerebrovascular diseases. Artificial intelligence (AI) is a branch of computer science which is used in a wide range of applications in agriculture, communications, medicine, finance, and other fields. In recent years, there are much research devoted to the application of AI to TCD. The review and summary of related technologies is an important work to promote the development of this field, which can provide an intuitive technical summary for future researchers. In this paper, we first review the development, principles, and applications of TCD ultrasonography and other related knowledge, and briefly introduce the development of AI in the field of medicine and emergency medicine. Finally, we summarize in detail the applications and advantages of AI technology in TCD ultrasonography including the establishment of an examination system combining brain computer interface (BCI) and TCD ultrasonography, the classification and noise cancellation of TCD ultrasonography signals using AI algorithms, and the use of intelligent robots to assist physicians in TCD ultrasonography and discuss the prospects for the development of AI in TCD ultrasonography.

Aging and Sex Differences in Brain Volume and Cerebral Blood Flow.

How do regional brain volume ratios and cerebral blood flow (CBF, mL/min) change with aging, and are there sex differences? This study aimed to comprehensively evaluate the relationships between regional brain volume ratios and CBF in healthy brains. The study participants were healthy volunteers who underwent three-dimensional T1-weighted MRI, time-of-flight MR angiography, and four-dimensional (4D) flow MRI between 2020 and 2022. The brain was automatically segmented into 21 brain subregions from 3D T1-weighted MRI, and CBF in 16 major intracranial arteries were measured by 4D flow MRI. The relationships between segmented brain volume ratios and CBFs around the circle of Willis were comprehensively investigated in each decade and sex. This study included 129 healthy volunteers (mean age ± SD, 48.2 ± 16.8; range, 22-92 years; 43 males and 86 females). The association was strongest between the cortical gray matter volume ratio and total outflow of the intracranial major arteries distal to the circle of Willis (Pearson's correlation coefficient, r: 0.425). In addition, the mean flow of the total inflow and outflow around the circle of Willis were significantly greater in women than men, and significant left-right differences were observed in CBFs even on the peripheral side of the circle of Willis. Moreover, the correlation was strongest between the left cortical gray matter volume ratio and the combined flows of the left anterior and posterior cerebral arteries distal to the circle of Willis (r: 0.486). There was a trend toward greater total intracranial CBF, especially among women in their 40s and younger, who had a larger cortical gray matter volume. This finding may be one of the reasons for the approximately twofold higher incidence of cerebral aneurysms and subarachnoid hemorrhage, and a threefold higher incidence of migraine headaches.

Chronic remote ischaemic conditioning in patients with symptomatic intracranial atherosclerotic stenosis (the RICA trial): a multicentre, randomised, double-blind sham-controlled trial in China

Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide, and it is associated with a high risk of recurrent stroke with currently recommended treatments. We aimed to evaluate the effect of chronic remote ischaemic conditioning on prevention of ischaemic events in patients with symptomatic ICAS. The RICA trial is a multicentre, randomised, double-blind, sham-controlled trial at 84 stroke centres in China. Patients aged 40-80 years with ischaemic stroke or transient ischaemic attack attributable to angiographically verified 50-99% stenosis of a major intracranial artery were randomly assigned (1:1), via an interactive web-based system by computer-generated randomisation code, to either remote ischaemic conditioning or sham remote ischaemic conditioning once daily for 12 months and voluntarily thereafter. All investigators and patients were masked to treatment allocation. The primary efficacy endpoint was the time to first occurrence of non-fatal or fatal ischaemic stroke, with survival analysed by the Kaplan-Meier method. Primary and safety analyses were done in the intention-to-treat population. The RICA trial is registered with ClinicalTrials.gov, number NCT02534545. Between Oct 28, 2015, and Feb 28, 2019, 3033 patients were enrolled and randomly assigned to either remote ischaemic conditioning (n=1517; intervention group) or sham remote ischaemic conditioning (n=1516; sham group). Median follow-up was 3·5 years (IQR 2·7-4·4). A non-fatal or fatal ischaemic stroke occurred in 257 (16·9%) patients in the intervention group compared with 288 (19·0%) patients in sham group. There was no difference in the survival distribution for time to first occurrence of non-fatal or fatal ischaemic stroke (hazard ratio 0·87, 95% CI 0·74-1·03; p=0·12). In the intervention group, 79 (5·2%) patients died from any cause, and in the sham group, 84 (5·5%) patients died from any cause (hazard ratio 0·93, 95% CI 0·68-1·27; p=0·65). No intervention-related serious adverse events were observed. No evidence was found for a difference between remote ischaemic conditioning and sham remote ischaemic conditioning in lowering the risk of ischaemic stroke in patients with symptomatic ICAS. The benefit of remote ischaemic conditioning might have been diluted by poor compliance. Future studies of remote ischaemic conditioning in this population should address challenges in patients' compliance and assess longer term treatment. Ministry of Science and Technology China, Beijing Municipal Education Commission, Beijing Municipal Finance Bureau. For the Chinese translation of the abstract see Supplementary Materials section.

Semi-automated mapping of occluded arterial segments in acute large vessel stroke from computed tomography angiography

Catheterisation of occluded artery is the most crucial step in the mechanical thrombectomy of large vessel occlusions. Being a blind procedure, potential major untoward events could be anticipated at this stage. In this study, we evaluated the feasibility of reconstruction of the occluded vascular segment from CT angiography, exploiting the attenuation difference between the clot and adjacent brain parenchyma. Twenty-five patients with large vessel occlusion who achieved TICI2B/3 recanalization were identified. The semi-automated reconstruction was done using an open-source 3D segmentation software by two observers. The generated arterial anatomy was categorized as congruent, if all the major arterial segments namely, internal carotid artery, M1 middle cerebral artery, bifurcation, and major divisions matched with post thrombectomy angiograms. The discrepancy of one or more than one arterial segment was classified as mild or total mismatch respectively. Congruent arterial mapping was possible in 88% and 92 % patients for observer 1 and observer 2 respectively, while mild mismatch was noted in two patients for both the observers. Mismatch mostly occurred in superior division for both observers(100% vs 66.6%). The interrater agreement was good (0.77) and the accuracy was not influenced by the length of the clot. The median time for reconstruction was 4 minutes for both the observers (p - 0.21). Delineation of the anatomy of the occluded major intracranial artery is possible and corresponds with the actual anatomy. It could be used as a guide during thrombectomy procedures.

Automated detection of intracranial artery stenosis and occlusion in magnetic resonance angiography: A preliminary study based on deep learning

Background and objectivesIntracranial atherosclerotic stenosis of a major intracranial artery is the common cause of ischemic stroke. We evaluate the feasibility of using deep learning to automatically detect intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography. MethodsIn a retrospective study, magnetic resonance images with radiological reports of intracranial arterial stenosis and occlusion were extracted. The images were randomly divided into a training set and a test set. The manual annotation of lesions with a bounding box labeled “moderate stenosis,” “severe stenosis,” “occlusion,” and “absence of signal” was considered as ground truth. A deep learning algorithm based on you only look once version 5 (YOLOv5) detection model was developed with the training set, and its sensitivity and positive predictive values to detect lesions were evaluated in the test set. ResultsA dataset of 200 examinations consisted of a total of 411 lesions—242 moderate stenoses, 84 severe stenoses, 70 occlusions, and 15 absence of signal. The magnetic resonance images contained 291 lesions in the training set and 120 lesions in the test set. The sensitivity and positive predictive values were 64.2 and 83.7%, respectively. The detection sensitivity in relation to the location was greatest in the internal carotid artery (86.2%). ConclusionsApplying deep learning algorithms in the automated detection of intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography is feasible and has great potential.

Contribution of intracranial artery stenosis to white matter hyperintensities progression in elderly Chinese patients: A 3-year retrospective longitudinal study.

Background and purposeThere have been controversial results in previous studies for the association between intracranial artery stenosis (ICAS) and white matter hyperintensities (WMHs), and the correlation of ICAS with the progression of WMHs is uncertain. The aim of this study was to investigate the association between ICAS and the progression of WMHs.MethodsIn this retrospective longitudinal study, we enrolled 302 patients aged 60 years and older who had received two brain MRI scans with a 3-year interval and was examined by CTA in the first MRI scan. We measured the stenosis of major intracranial arteries by CTA and assessed the progression of WMHs using the modified Rotterdam Progression scale (mRPS). We performed binary logistic regression analyses and established linear regression model to determine the relationship between the degree of ICAS and the progression of WMHs.ResultsA total of 302 patients were enrolled, of which 48.3% experienced WMHs progression. After adjustment for confounding factors, the patients with Grade 2 ICAS had an OR of 2.8 (95% CI 1.4–5.5), and those with Grade 3 ICAS had an OR of 3.0 (95% CI 1.2–7.3) for the progression of WMHs. The ICAS degree remained associated with PVWMHs but had an attenuated relation to SCWMHs. ICAS severity was significantly associated with WMHs progression scores, higher for Grade 3 ICAS [β (SE) = 0.18 (0.18)] followed by Grade 2 ICAS [β (SE) = 0.10 (0.15)] compared with Grade 1 ICAS.ConclusionsPatients with more severe ICAS are more likely to have WMHs progression and have distinct relevancy to PVWMHs and SCWMHs, which may provide clues for understanding mechanisms of WMHs progression.

Anomalous origin of a middle cerebral artery from anterior cerebral artery with no association to an accessory or duplicated middle cerebral artery

The middle cerebral artery (MCA) is one of the major paired intracranial arteries involved in the formation of the circle of Willis. MCA is the most complex of the intracranial arteries mainly because it supplies the cerebral neocortex, which has been significantly developed in humans. The MCA is a recent phylogenetic acquisition and can be considered as a collateral branch of the anterior cerebral artery (ACA). Anomalies of the middle cerebral artery are less commonly reported than other intracranial arteries. Previously, described anomalies include accessory MCA, duplicated MCA, fenestration of MCA and variations of the branching patterns. Recently, several reports have been published describing unfused or twig-like MCA, in which the single MCA trunk is substituted by a collateral plexiform arterial network. This manuscript would like to report our unique case of an anomalous MCA origin from the anterior cerebral artery unassociated with duplication or accessory MCA.