Comparison of automated ASPECTS, large vessel occlusion detection and CTP analysis provided by Brainomix and RapidAI in patients with suspected ischaemic stroke.

OBJECTIVES: The ischaemic core and penumbra volumes derived from CTP aid the selection of patients with an arterial occlusion for mechanical thrombectomy. Different post-processing software packages may give different CTP outputs, potentially causing variable patient selection for mechanical thrombectomy. The study aims were, firstly, to assess the correlation in CTP outputs from software packages provided by Brainomix and RapidAI. Secondly, the correlation between automated ASPECTS and neuroradiologist-derived ASPECTS and accuracy in detecting large vessel occlusion was assessed. MATERIALS AND METHODS: This retrospective study included patients undergoing CTP for suspected anterior circulation large vessel occlusion. Pearson's correlation coefficient was used for testing the correlation in CTP outputs, ASPECTS/automated ASPECTS, and-in those with complete or near complete occlusion-final infarct volume. Diagnostic statistics were calculated for large vessel occlusion detection. RESULTS: Correlation was high for ischaemic core and penumbra volumes (0.862 and 0.832, respectively) but lower for the mismatch ratio (0.477). Agreement in mechanical thrombectomy eligibility was achieved in 85% of cases (46/54). Correlation between ischaemic core and final infarct volume was higher for Brainomix (0.757) than for RapidAI (0.595). The correlation between ASPECTS and automated ASPECTS (0.738 and 0.659) and the accuracy of detecting large vessel occlusion (77% and 71%) was higher for Brainomix than for RapidAI. CONCLUSION: There was high correlation between the CTP output from Brainomix and RapidAI. However, there was a difference in MT eligibility in 15% of cases, which highlights that the decision regarding MT should not be based on imaging parameters alone.

Monogenetic Stroke Syndromes in Children and Young Adults.

OBJECTIVE. The purpose of this article is to review the characteristic CT and MRI findings associated with monogenetic causes of ischemic and hemorrhagic stroke in children and young adults. CONCLUSION. Ischemic and hemorrhagic stroke in children and young adults remains a common cause of acquired disability but is underrecognized. Brain parenchymal and vascular imaging is commonly performed as part of the comprehensive evaluation of young patients presenting with stroke. Familiarity with these patterns of disease enables early recognition of an underlying inherited condition.

Vascular Anatomy Predicts the Risk of Cerebral Ischemia in Patients Randomized to Carotid Stenting Versus Endarterectomy.

BACKGROUND AND PURPOSE: Complex vascular anatomy might increase the risk of procedural stroke during carotid artery stenting (CAS). Randomized controlled trial evidence that vascular anatomy should inform the choice between CAS and carotid endarterectomy (CEA) has been lacking. METHODS: One-hundred eighty-four patients with symptomatic internal carotid artery stenosis who were randomly assigned to CAS or CEA in the ICSS (International Carotid Stenting Study) underwent magnetic resonance (n=126) or computed tomographic angiography (n=58) at baseline and brain magnetic resonance imaging before and after treatment. We investigated the association between aortic arch configuration, angles of supra-aortic arteries, degree, length of stenosis, and plaque ulceration with the presence of ≥1 new ischemic brain lesion on diffusion-weighted magnetic resonance imaging (DWI+) after treatment. RESULTS: Forty-nine of 97 patients in the CAS group (51%) and 14 of 87 in the CEA group (16%) were DWI+ (odds ratio [OR], 6.0; 95% confidence interval [CI], 2.9-12.4; P<0.001). In the CAS group, aortic arch configuration type 2/3 (OR, 2.8; 95% CI, 1.1-7.1; P=0.027) and the degree of the largest internal carotid artery angle (≥60° versus <60°; OR, 4.1; 95% CI, 1.7-10.1; P=0.002) were both associated with DWI+, also after correction for age. No predictors for DWI+ were identified in the CEA group. The DWI+ risk in CAS increased further over CEA if the largest internal carotid artery angle was ≥60° (OR, 11.8; 95% CI, 4.1-34.1) than if it was <60° (OR, 3.4; 95% CI, 1.2-9.8; interaction P=0.035). CONCLUSIONS: Complex configuration of the aortic arch and internal carotid artery tortuosity increase the risk of cerebral ischemia during CAS, but not during CEA. Vascular anatomy should be taken into account when selecting patients for stenting. CLINICAL TRIAL REGISTRATION: URL: http://www.isrctn.com/ISRCTN25337470. Unique identifier: ISRCTN25337470.

Carotid stenting versus endarterectomy.

Since the landmark NASCET and ECST trials demonstrated the superiority of carotid endarterectomy over medical therapy in the prevention of stroke for patients with symptomatic carotid artery stenosis, surgical intervention as a part of secondary prevention of stroke has become widespread. However, the newer technology of carotid artery angioplasty and stenting challenges this mode of intervention, promising the benefits of a procedure under local anesthesia and potentially avoiding the surgical complications of cranial nerve palsy and hematoma. Pooled evidence from randomized controlled trials of endarterectomy versus stenting shows a higher rate of stroke or death in the stenting groups-but this finding is mitigated to an extent by the lower incidence of myocardial infarction and cranial nerve palsy in patients undergoing stenting. At present, carotid endarterectomy combined with optimal drug therapy remains the standard of care for symptomatic 70%-99% stenosis of the internal carotid artery, but stenting might be an option in younger patients and in those not suitable for endarterectomy.

Clinical, Imaging and Neurogenetic Features of Patients with Gliomatosis Cerebri Referred to a Tertiary Neuro-Oncology Centre.

INTRODUCTION: Gliomatosis cerebri describes a rare growth pattern of diffusely infiltrating glioma. The treatment options are limited and clinical outcomes remain poor. To characterise this population of patients, we examined referrals to a specialist brain tumour centre. METHODS: We analysed demographic data, presenting symptoms, imaging, histology and genetics, and survival in individuals referred to a multidisciplinary team meeting over a 10-year period. RESULTS: In total, 29 patients fulfilled the inclusion criteria with a median age of 64 years. The most common presenting symptoms were neuropsychiatric (31%), seizure (24%) or headache (21%). Of 20 patients with molecular data, 15 had IDH wild-type glioblastoma, with an IDH1 mutation most common in the remainder (5/20). The median length of survival from MDT referral to death was 48 weeks (IQR 23 to 70 weeks). Contrast enhancement patterns varied between and within tumours. In eight patients who had DSC perfusion studies, five (63%) had a measurable region of increased tumour perfusion with rCBV values ranging from 2.8 to 5.7. A minority of patients underwent MR spectroscopy with 2/3 (66.6%) false-negative results. CONCLUSIONS: Gliomatosis imaging, histological and genetic findings are heterogeneous. Advanced imaging, including MR perfusion, could identify biopsy targets. Negative MR spectroscopy does not exclude the diagnosis of glioma.

Real-world evaluation of Brainomix e-Stroke software.

BACKGROUND AND PURPOSE: Brainomix e-Stroke is an artificial intelligence-based decision support tool that aids the interpretation of CT imaging in the context of acute stroke. While e-Stroke has the potential to improve the speed and accuracy of diagnosis, real-world validation is essential. The aim of this study was to prospectively evaluate the performance of Brainomix e-Stroke in an unselected cohort of patients with suspected acute ischaemic stroke. METHODS: The study cohort included all patients admitted to the University College London Hospital Hyperacute Stroke Unit between October 2021 and April 2022. For e-ASPECTS and e-CTA, the ground truth was determined by a neuroradiologist with access to all clinical and imaging data. For e-CTP, the values of the core infarct and ischaemic penumbra were compared with those derived from syngo.via, an alternate software used at our institution. RESULTS: 1163 studies were performed in 551 patients admitted during the study period. Of these, 1130 (97.2%) were successfully processed by e-Stroke in an average of 4 min. For identifying acute middle cerebral artery territory ischaemia, e-ASPECTS had an accuracy of 77.0% and was more specific (83.5%) than sensitive (58.6%). The accuracy for identifying hyperdense thrombus was lower (69.1%), which was mainly due to many false positives (positive predictive value of 22.9%). Identification of acute haemorrhage was highly accurate (97.8%) with a sensitivity of 100% and a specificity of 97.6%; false positives were typically caused by areas of calcification. The accuracy of e-CTA for large vessel occlusions was 91.5%. The core infarct and ischaemic penumbra volumes provided by e-CTP strongly correlated with those provided by syngo.via (ρ=0.804-0.979). CONCLUSION: Brainomix e-Stroke software provides rapid and reliable analysis of CT imaging in the acute stroke setting although, in line with the manufacturer's guidance, it should be used as an adjunct to expert interpretation rather than a standalone decision-making tool.

Neuroimaging in Sickle Cell Disease: A Review.

Sickle cell disease is the most common hereditary hemoglobinopathy, which results in abnormally shaped and rigid red blood cells. These sickle-shaped red blood cells cause vaso-occlusion and ischemic phenomena that can affect any organ in the body. As a common cause of disability, the neurological manifestations of sickle cell disease are particularly important. Neuroimaging has a crucial role in the diagnosis, management, and prevention of the complications of sickle cell disease. These complications can affect the brain parenchyma, vasculature, and skull and can be ascribed directly or indirectly to a vasculopathy of small and large vessels. Vaso-occlusion can cause ischemic stroke. Ischemic damage in the absence of an acute neurological deficit, and therefore only apparent on neuroimaging, is termed silent cerebral ischemia. Weakening of the arterial walls can cause aneurysms. In its most severe form, a vasculopathy of the terminal internal carotid arteries can progress to moyamoya syndrome, characterized by steno-occlusive disease and the formation of friable collateral arteries. Rupture of aneurysms or friable collateral arteries is a potential cause of intracranial hemorrhage. The skull and vertebrae may be affected by extra-medullary hematopoiesis, due to severe anemia, or iron deposition, due to chronic red blood cell transfusion. Impaired blood supply to bone is associated with osteomyelitis and osteonecrosis. Fat embolization syndrome is a rare complication of osteonecrosis, which may cause devastating neurological impairment. Awareness and early recognition of the diverse manifestations of sickle cell disease on neuroimaging is crucial to ensure optimal treatment in a complex patient cohort.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): a randomised controlled trial with cost-effectiveness analysis.

BACKGROUND: Carotid artery stenting (CAS) is an alternative to carotid endarterectomy (CEA) for the treatment of carotid stenosis, but safety and long-term efficacy were uncertain. OBJECTIVE: To compare the risks, benefits and cost-effectiveness of CAS versus CEA for symptomatic carotid stenosis. DESIGN: International, multicentre, randomised controlled, open, prospective clinical trial. SETTING: Hospitals at 50 centres worldwide. PARTICIPANTS: Patients older than 40 years of age with symptomatic atheromatous carotid artery stenosis. INTERVENTIONS: Patients were randomly allocated stenting or endarterectomy using a computerised service and followed for up to 10 years. MAIN OUTCOME MEASURES: The primary outcome measure was the long-term rate of fatal or disabling stroke, analysed by intention to treat (ITT). Disability was assessed using the modified Rankin Scale (mRS). A cost-utility analysis estimating mean costs and quality-adjusted life-years (QALYs) was calculated over a 5-year time horizon. RESULTS: A total of 1713 patients were randomised but three withdrew consent immediately, leaving 1710 for ITT analysis (853 were assigned to stenting and 857 were assigned to endarterectomy). The incidence of stroke, death or procedural myocardial infarction (MI) within 120 days of treatment was 8.5% in the CAS group versus 5.2% in the CEA group (72 vs. 44 events) [hazard ratio (HR) 1.69, 95% confidence interval (CI) 1.16 to 2.45; p = 0.006]. In the analysis restricted to patients who completed stenting, age independently predicted the risk of stroke, death or MI within 30 days of CAS (relative risk increase 1.17% per 5 years of age, 95% CI 1.01% to 1.37%). Use of an open-cell stent conferred higher risk than a closed-cell stent (relative risk 1.92, 95% CI 1.11 to 3.33), but use of a cerebral protection device did not modify the risk. CAS was associated with a higher risk of stroke in patients with an age-related white-matter changes score of 7 or more (HR 2.98, 95% CI 1.29 to 6.93; p = 0.011). After completion of follow-up with a median of 4.2 years, the number of patients with fatal or disabling stroke in the CAS and CEA groups (52 vs. 49), and the cumulative 5-year risk did not differ significantly (6.4% vs. 6.5%) (HR 1.06, 95% CI 0.72 to 1.57; p = 0.776). Stroke of any severity was more frequent in the CAS group (15.2% vs. 9.4% in the CEA group) (HR 1.712, 95% CI 1.280 to 2.300; p < 0.001). There was no significant difference in long-term rates of severe carotid restenosis or occlusion (10.8% in the CAS group vs. 8.6% in the CEA group) (HR 1.25, 95% CI 0.89 to 1.75; p = 0.20). There was no difference in the distribution of mRS scores at 1-year, 5-year or final follow-up. There were no differences in costs or QALYs between the treatments. LIMITATIONS: Patients and investigators were not blinded to treatment allocation. Interventionists' experience of stenting was less than that of surgeons with endarterectomy. Data on costs of managing strokes were not collected. CONCLUSIONS: The functional outcome after stenting is similar to endarterectomy, but stenting is associated with a small increase in the risk of non-disabling stroke. The choice between stenting and endarterectomy should take into account the procedural risks related to individual patient characteristics. Future studies should include measurement of cognitive function, assessment of carotid plaque morphology and identification of clinical characteristics that determine benefit from revascularisation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN25337470. FUNDING: This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 20. See the NIHR Journal Library website for further project information. Further funding was provided by the Medical Research Council, Stroke Association, Sanofi-Synthélabo and the European Union.