T Cells Immune Imbalance Present in Patients With Multiple Intracranial Aneurysms.

Growing evidence suggests that systemic immune and inflammatory responses may play a critical role in the formation and development of aneurysms. Exploring the differences between single intracranial aneurysm (SIA) and multiple IAs (MIAs) could provide insights for targeted therapies. However, there is a lack of comprehensive and detailed characterization of changes in circulating immune cells in MIAs. Peripheral blood mononuclear cell (PBMC) samples from patients with SIA (n = 16) or MIAs (n = 6) were analyzed using high-dimensional mass cytometry to evaluate the frequency and phenotype of immune cell subtypes. A total of 25 cell clusters were identified, revealing that the immune signature of MIAs included cluster changes. Compared to patients with SIA, patients with MIAs exhibited immune dysfunction and regulatory imbalance in T-cell clusters. They also had reduced numbers of CD8+ T cells and their subgroups CD8+ Te and CD8+ Tem cells, as well as reduced numbers of the CD4+ T-cell subgroup CD27-CD4+ Tem cells. Furthermore, compared to SIA, MIAs were associated with enhanced T-cell immune activation, with elevated expression levels of CD3, CD25, CD27, CCR7, GP130, and interleukin 10. This study provides insights into the circulating immune cell profiles in patients with MIAs, highlighting the similarities and differences between patients with SIA and those with MIAs. Furthermore, the study suggests that circulating immune dysfunction may contribute to development of MIAs.

Neuroform atlas stent treatment for 533 intracranial aneurysms in a large Chinese cohort: complication risk factor analysis.

BACKGROUND: The newest generation of Neuroform Atlas stent™ (Stryker, Fremont, California) represents a recent advance of cerebral laser-cut microstents for the treatment of intracranial wide-necked aneurysms, and postoperative complications have been observed among Western patients. We assessed predictors of complications, morbidity, and unfavourable outcomes in a large cohort of patients with aneurysms that were treated with Neuroform Atlas stents in China. METHODS: This retrospective study included subjects who were treated with Atlas stents in China from November 2020 to January 2022. RESULTS: A total of 522 consecutive patients (mean age, 58.9 ± 9.9 years; female, 65.3% [341/522]) with 533 aneurysms were included in the study. In the early postoperative period, the neurological morbidity rate was 7.3% (38/522), the ischaemic stroke rate was 5.0% (26/522), the aneurysm rupture subarachnoid haemorrhage rate was 2.3% (12/522), and the mRS score deterioration rate was 5.4% (28/522). The mortality rate was 0.8% (4/522) in the postoperative period. The rate of neurological morbidity during the follow-up period was 1.2% (6/486). In the multifactor prediction analysis, cerebral infarction, Hunt-Hess grade (3-5), procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of neurologic morbidity. The procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of mRS score deterioration. CONCLUSIONS: The incidence of SCA (stent-assisted coiling)-related complications with the Atlas stent in this study population was comparable to that in Western populations. We identified the procedure duration and stent length as novel independent predictors of SCA-related ischaemic stroke, neurological morbidity, and mRS score deterioration among the Chinese population.

Infectious endocarditis complicated with intracranial infected aneurysm rupture and sinus of valsalva aneurysm rupture.

BACKGROUND: Infectious endocarditis (IE) is an infectious disease caused by direct invasion of the heart valve, endocardium, or adjacent large artery endocardium by pathogenic microorganisms. Despite its relatively low incidence, it has a poor prognosis and a high mortality. Intracranial infectious aneurysms (IIA) and ruptured sinus of Valsalva aneurysm (RSVA) are rare complications of IE. CASE PRESENTATION: We report a young male patient with symptoms of respiratory tract infection, heart murmurs and other symptoms and signs. The patient also had kidney function impairment and poor response to symptomatic therapy. Blood culture was negative, but echocardiography was positive, which met the diagnostic criteria for infective endocarditis. Moreover, an echocardiography showed a ruptured sinus of Valsalva aneurysm with a ventricular septal defect. Finally, secondary rupture of an IIA with multiple organ damage led to a poor clinical outcome. CONCLUSION: Therefore, in the clinical setting, for young patients with unexplained fever, chest pain, or palpitations, we need to be highly vigilant, considering the possibility of infective endocarditis and promptly performing blood culture, echocardiography, cerebrovascular imaging and so on, in order to facilitate early proper diagnosis and treatment.

Dietary factors and the incidence of intracranial aneurysms: a Mendelian randomization research.

BACKGROUND: Intracranial aneurysms (IAs) pose a significant threat to morbidity and mortality, yet their etiology remains inadequately comprehended. The present study employs Mendelian randomization (MR) to investigate the relationship among dietary elements with IAs, encompassing unruptured intracranial aneurysms (uIA) as well as aneurysmal subarachnoid hemorrhage (aSAH). METHODS: The current study employed a double-sample MR test utilizing genome-wide association study (GWAS) summary data from the IEU and IAs' meta-analysis to investigate the genetically predicted consumption levels of various dietary factors using GWAS data. Causation was assessed by techniques of MR-Egger, weighted mode, and median, as well as IVW. To guarantee the accuracy of the results, pleiotropy and heterogeneity evaluations were also carried out. RESULTS: The findings of the study indicate a positive correlation between the intake of alcohol, lamb/mutton, and pork with the risk of IAs (IVW all p < 0.05). Conversely, a negative correlation was observed regarding dried fruit consumption and the risk of aSAH (IVW p < 0.05). There was only scant evidence supporting the association between alcohol intake frequency and an elevated risk of uIA (IVW method p < 0.05). The MR analysis outcomes were authenticated by the MR-PRESSO method and were deemed reliable. Furthermore, sensitivity calculations, such as pleiotropy and homogeneity test, leave-one-out evaluation, and funnel charts, validated the robustness of the results. CONCLUSIONS: The findings suggest that reducing alcohol, lamb/mutton, and pork intake, and increasing dried fruit intake may be potential strategies for the prevention of IAs and aSAH. Additional research is necessary to validate these outcomes and elucidate the underlying mechanisms.

Clipping of Anterior Circulation Aneurysms: Operative Instructions and Safety Rules for Young Cerebrovascular Surgeons.

INTRODUCTION: Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever. MATERIALS AND METHODS: We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations. RESULTS: We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping. CONCLUSION: In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Nomogram-based geometric and hemodynamic parameters for predicting the growth of small untreated intracranial aneurysms.

Previous studies have shown that the growth status of intracranial aneurysms (IAs) predisposes to rupture. This study aimed to construct a nomogram for predicting the growth of small IAs based on geometric and hemodynamic parameters. We retrospectively collected the baseline and follow-up angiographic images (CTA/ MRA) of 96 small untreated saccular IAs, created patient-specific vascular models and performed computational fluid dynamics (CFD) simulations. Geometric and hemodynamic parameters were calculated. A stepwise Cox proportional hazards regression analysis was employed to construct a nomogram. IAs were stratified into low-, intermediate-, and high-risk groups based on the total points from the nomogram. Receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis (DCA) and Kaplan-Meier curves were evaluated for internal validation. In total, 30 untreated saccular IAs were grown (31.3%; 95%CI 21.8%-40.7%). The PHASES, ELAPSS, and UIATS performed poorly in distinguishing growth status. Hypertension (hazard ratio [HR] 4.26, 95%CI 1.61-11.28; P = 0.004), nonsphericity index (95%CI 4.10-25.26; P = 0.003), max relative residence time (HR 1.01, 95%CI 1.00-1.01; P = 0.032) were independently related to the growth status. A nomogram was constructed with the above predictors and achieved a satisfactory prediction in the validation cohort. The log-rank test showed significant discrimination among the Kaplan-Meier curves of different risk groups in the training and validation cohorts. A nomogram consisting of geometric and hemodynamic parameters presented an accurate prediction for the growth status of small IAs and achieved risk stratification. It showed higher predictive efficacy than the assessment tools.

Comparison of LVIS and Enterprise stent-assisted coiling embolization for ruptured intracranial aneurysms: a propensity score-matched cohort study.

The role of a low-profile visualized intraluminal support stent (LVIS) and Enterprise in the treatment of unruptured intracranial aneurysms is well established. Although previous studies have investigated one single type of stent for the treatment of ruptured intracranial aneurysms (RIA), the safety and efficacy between the two types of stents has not been fully explored. Herein we conducted a study to compare the outcomes of the two stents for treatment of RIA. This is a prospective registry database of aneurysmal subarachnoid hemorrhage (aSAH) patients admitted to a single institution between 2018 and 2021. We collected patient baseline information, secondary complications, follow-up angiographic data, long-term prognostic outcomes, and conducted propensity score matching (PSM) analysis with 1:1 ratio and a multivariable logistic regression to compare the outcomes of the two types of stents. A total of 231 patients with RIAs were included in this study, with 108 treated using the LVIS device and 123 treated using the Enterprise device. Before PSM analysis, only the incidence of poor prognosis after 12 months was higher in the Enterprise group comparing to the LVIS group (20% vs. 10%, P = 0.049). After PSM analysis, there was a higher occurrence of delayed cerebral ischemia (DCI) in the Enterprise group compared to the LVIS group (odds ratio [OR] 3.95, 95% confidence interval [CI] [1.20-13.01], P = 0.024). However, no significant difference in prognosis was observed after PSM adjustment. Furthermore, subgroup analysis revealed that patients with female (P = 0.019), hypertension (P = 0.048), and anterior circulation aneurysms (P = 0.019) receiving the Enterprise device had a higher risk of DCI. The overall efficacy of LVIS and Enterprise in the treatment of RIA is comparable, while the incidence of DCI in the LVIS group is lower than that in the Enterprise group after PSM analysis. Registration number: NCT05738083 ( https://clinicaltrials.gov/ ).

Onyx prevents the bleeding of ruptured aneurysms during interventional embolization.

Endovascular treatment has been acknowledged as an effective treatment for intracranial aneurysms, showcasing favorable clinical outcomes and providing robust protection against rebleeding and rupture. Notably, during the endovascular procedure, significant complications include intraprocedural aneurysmal rupture (IAR) induced by microcatheters, microguidewires, or spring coils, along with thromboembolic events, significantly escalating patient mortality and disability. Current approaches against for IARs involve various strategies such as heparin reversal, compression of the common carotid artery or upstream soft guidewire to mitigate blood flow, management of intracranial pressure and blood pressure, and balloon-assisted or unassisted rapid dense embolization of the aneurysm. Nevertheless, these measures may prove insufficient in halting hemorrhage, especially in scenarios where additional coils cannot be added for dense embolization due to inherent limitations. In this context, we introduce a novel strategy for the prompt, safe, and effective cessation of aneurysm bleeding, which involves injecting an appropriate quantity of Onyx into the aneurysm through a microcatheter while safeguarded by an aneurysm-carrying arterial braided stent. Initially, we attempted dense embolization by filling multiple coils. However, in cases where continued coil filling proved unfeasible or failed to sufficiently prevent contrast agent extravasation, we opted for Onyx injection into the aneurysm. Utilizing Onyx effectively prevented further blood extravasation without adversely impacting the aneurysm-carrying artery or distal vessels, leading to favorable prognoses for all patients. This article delineates our embolization strategy, highlighting the efficacy and safety of Onyx injection as an alternative or complementary measure in managing complications arising from endovascular coil embolization.

Improving intracranial aneurysms image quality and diagnostic confidence with deep learning reconstruction in craniocervical CT angiography.

BACKGROUND: The diagnostic impact of deep learning computed tomography (CT) reconstruction on intracranial aneurysm (IA) remains unclear. PURPOSE: To quantify the image quality and diagnostic confidence on IA in craniocervical CT angiography (CTA) reconstructed with DEep Learning Trained Algorithm (DELTA) compared to the routine hybrid iterative reconstruction (HIR). MATERIAL AND METHODS: A total of 60 patients who underwent craniocervical CTA and were diagnosed with IA were retrospectively enrolled. Images were reconstructed with DELTA and HIR, where the image quality was first compared in noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Next, two radiologists independently graded the noise appearance, arterial sharpness, small vessel visibility, conspicuity of calcifications that may present in arteries, and overall image quality, each with a 5-point Likert scale. The diagnostic confidence on IAs of various sizes was also graded. RESULTS: Significantly lower noise and higher SNR and CNR were found on DELTA than on HIR images (all P < 0.05). All five subjective metrics were scored higher by both readers on the DELTA images (all P < 0.05), with good to excellent inter-observer agreement (κ = 0.77-0.93). DELTA images were rated with higher diagnostic confidence on IAs compared to HIR (P < 0.001), particularly for those with size ≤3 mm, which were scored 4.5 ± 0.6 versus 3.4 ± 0.8 and 4.4 ± 0.7 versus 3.5 ± 0.8 by two readers, respectively. CONCLUSION: The DELTA shows potential for improving the image quality and the associated confidence in diagnosing IA that may be worth consideration for routine craniocervical CTA applications.

Delayed traumatic intracranial aneurysms: literature review and case series.

Traumatic intracranial aneurysm (TICA) is a rare and aggressive pathology that requires prompt treatment. Nevertheless, early vascular imaging following head trauma may yield falsely negative results, underscoring the importance of subsequent imaging within the first week to detect delayed TICAs. This study aims to report our experience with delayed TICAs and highlight the clinical importance of repeated angiographic screening for delayed TICAs. In this retrospective analysis, we evaluated patients managed for a TICA at a tertiary care teaching institution over the last decade. Additionally, we conducted a systematic review of the literature, following the PRISMA guidelines, on previously reported TICAs, focusing on the time lag between the injury and diagnosis. Twelve delayed TICAs were diagnosed in 9 patients. The median time interval from injury to diagnosis was 2 days (IQR: 1-22 days), and from diagnosis to treatment was 2 days (IQR: 0-9 days). The average duration of radiological follow-up was 28 ± 38 months. At the final follow-up, four patients exhibited favorable neurological outcomes, while the remainder had adverse outcomes. The mortality rate was 22%. Literature reviews identified 112 patients with 114 TICAs, showcasing a median diagnostic delay post-injury of 15 days (IQR: 6-44 days), with 73% diagnosed beyond the first week post-injury. The median time until aneurysm rupture was 9 days (IQR: 3-24 days). Our findings demonstrate acceptable outcomes following TICA treatment and highlight the vital role of repeated vascular imaging after an initial negative computed tomography or digital subtraction angiography in excluding delayed TICAs.

Risk factors of unruptured intracranial aneurysms instability in the elderly.

BACKGROUND: Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population. METHODS: In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60 years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted. RESULTS: A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4 mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7 mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms. CONCLUSIONS: In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors.

Elucidating key immunological biomarkers and immune microenvironment dynamics in aging-related intracranial aneurysm through integrated multi-omics analysis.

BACKGROUND: The exact cause of intracranial aneurysms (IA) is still unclear. However, pro-inflammatory factors are known to contribute to IA progression. The specific changes in the immune microenvironment of IAs remain largely unexplored. METHODS: This study analyzed single-cell sequencing data from a male mouse model of brain aneurysm, focusing on samples before and after elastase-induced Willis aneurysms. The data helped identify eight distinct cell subpopulations: fibroblasts, macrophages, NK cells, endothelial cells, B cells, granulocytes, and monocytes. The study also involved bulk RNA sequencing of 97 IA samples, utilizing ssGSEA and CIBERSORT algorithms for analysis. Intercellular communication among these cells was inferred to understand the immune dynamics in IA. RESULTS: The study found that fibroblasts and macrophages are predominant in various disease states of IA. Notably, the onset of IA was marked by a significant increase in fibroblasts and a decrease in macrophages. There was a marked increase in cellular interactions, especially involving macrophages, at the onset of the disease. Through enrichment analysis, 12 potential immunogenic biomarkers were identified. Of these, Rgs1 emerged as a critical molecule in IA formation, confirmed through secondary validation in a single-cell sequencing dataset. CONCLUSION: This comprehensive analysis of immune cell composition and intercellular communication in IA tissues highlights the significant roles of macrophages and the molecule Rgs1. These findings shed light on the physiological and pathological conditions of IA, offering new insights into its immune microenvironment.

Autosomal Dominant Polycystic Kidney Disease: Extrarenal Involvement.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder, but kidneys are not the only organs involved in this systemic disorder. Individuals with the condition may display additional manifestations beyond the renal system, involving the liver, pancreas, and brain in the context of cystic manifestations, while involving the vascular system, gastrointestinal tract, bones, and cardiac valves in the context of non-cystic manifestations. Despite kidney involvement remaining the main feature of the disease, thanks to longer survival, early diagnosis, and better management of kidney-related problems, a new wave of complications must be faced by clinicians who treated patients with ADPKD. Involvement of the liver represents the most prevalent extrarenal manifestation and has growing importance in the symptom burden and quality of life. Vascular abnormalities are a key factor for patients' life expectancy and there is still debate whether to screen or not to screen all patients. Arterial hypertension is often the earliest onset symptom among ADPKD patients, leading to frequent cardiovascular complications. Although cardiac valvular abnormalities are a frequent complication, they rarely lead to relevant problems in the clinical history of polycystic patients. One of the newest relevant aspects concerns bone disorders that can exert a considerable influence on the clinical course of these patients. This review aims to provide the "state of the art" among the extrarenal manifestation of ADPKD.

Hemodynamic alterations of flow diverters on aneurysms at the fetal posterior communicating artery: A simulation study using CFD to compare the surpass streamline, pipeline flex, and tubridge devices.

PURPOSE: Traditional flow diverters (FDs) for treating aneurysms at the fetal posterior communicating artery are unsatisfactory. Surpass Streamline is a novel FD with different mesh characteristics; however, the outcomes for such aneurysms remain unclear. This study aimed to compare hemodynamic alterations induced by Surpass Streamline, Pipeline Flex, and Tubridge devices and explore possible strategies for aneurysms at the fetal posterior communicating artery. METHODS: Two simulated aneurysms (Case 1, Case 2) were constructed from digital subtraction angiography (DSA). The three FDs were virtually deployed, and hemodynamic analysis based on computational fluid dynamics was performed. Hemodynamic parameters, including the sac-averaged velocity magnitude (Velocity), high-flow volume (HFV), and wall shear stress (WSS), were compared between each FD and the untreated model (control). Surpass Streamline was performed in real life for two aneurysms and the clinical outcomes were collected for analysis. RESULTS: Compared to the control, the Surpass resulted in the most significant reduction in flow. In Case 1, the Velocity, HFV, and WSS were reduced by 51.6%, 78.1%, and 64.3%, respectively. In Case 2, the Velocity, HFV, and WSS were reduced by 48.0%, 81.1%, and 65.3%, respectively. Tubridge showed slightly larger changes in hemodynamic parameters than Pipeline. In addition, our analysis suggested that metal coverage was correlated with the WSS, Velocity, and HFV. The postoperative DSA showed that the aneurysm was nearly occluded in Case 1 and decreased in Case 2. CONCLUSION: Compared to that with the Pipeline and Tubridge, the Surpass resulted in the greatest reduction in hemodynamic parameters and might be effective for aneurysms at the fetal posterior communicating artery. Virtual FD deployment and computational fluid dynamics analysis may be used to predict the treatment outcomes.

DNA methylation regulator-mediated modification patterns and risk of intracranial aneurysm: a multi-omics and epigenome-wide association study integrating machine learning, Mendelian randomization, eQTL and mQTL data.

BACKGROUND: Intracranial aneurysms (IAs) pose a significant and intricate challenge. Elucidating the interplay between DNA methylation and IA pathogenesis is paramount to identify potential biomarkers and therapeutic interventions. METHODS: We employed a comprehensive bioinformatics investigation of DNA methylation in IA, utilizing a transcriptomics-based methodology that encompassed 100 machine learning algorithms, genome-wide association studies (GWAS), Mendelian randomization (MR), and summary-data-based Mendelian randomization (SMR). Our sophisticated analytical strategy allowed for a systematic assessment of differentially methylated genes and their implications on the onset, progression, and rupture of IA. RESULTS: We identified DNA methylation-related genes (MRGs) and associated molecular pathways, and the MR and SMR analyses provided evidence for potential causal links between the observed DNA methylation events and IA predisposition. CONCLUSION: These insights not only augment our understanding of the molecular underpinnings of IA but also underscore potential novel biomarkers and therapeutic avenues. Although our study faces inherent limitations and hurdles, it represents a groundbreaking initiative in deciphering the intricate relationship between genetic, epigenetic, and environmental factors implicated in IA pathogenesis.

HIV-associated multiple intracranial aneurysms and stroke in an adult patient: successful treatment with a combination of glucocorticoid and antiviral agents.

A 35-year-old Iranian man with an 18-year history of human immunodeficiency virus (HIV) infection developed sudden left-sided hemiparesis and mild dysarthria. Based on laboratory results, brain and neck computerized tomography angiography (CTA), echocardiography, hypercoagulability tests, and vasculitis tests, the patient was diagnosed with a stroke with multiple intracranial aneurysms secondary to HIV. Cerebral aneurysms and stroke are uncommon in HIV-infected patients, and the aneurysms' exact cause and risk factors are unknown. There is currently no effective regimen or definitive treatment for HIV-associated vasculitis. In the present study, the patient recovered without any neurological deficits following treatment with oral prednisolone, combined with combination antiretroviral therapy (cART), valacyclovir, and antiplatelet medication. Furthermore, after 2 months of immunosuppressive treatment, all imaging abnormalities improved, and no new events were observed at the 20-month follow-up. To the best of our knowledge, this is the first case in which a patient with HIV-associated vasculopathy and stroke has survived successfully, and all angiographic abnormalities completely eliminated.

A deep learning framework for intracranial aneurysms automatic segmentation and detection on magnetic resonance T1 images.

OBJECTIVES: To design a deep learning-based framework for automatic segmentation and detection of intracranial aneurysms (IAs) on magnetic resonance T1 images and test the robustness and performance of framework. METHODS: A retrospective diagnostic study was conducted based on 159 IAs from 136 patients who underwent the T1 images. Among them, 127 cases were randomly selected for training and validation, and 32 cases were used to assess the accuracy and consistency of our algorithm. We developed and assembled three convolutional neural networks for the segmentation and detection of IAs. The segmentation and detection performance of the model were compared with the ground truth, and various metrics were calculated at the voxel level, IAs level, and patient level to show the performance of our framework. RESULTS: Our assembled model achieved overall Dice, voxel-level sensitivity, specificity, balanced accuracy, and F1 score of 0.802, 0.874, 0.9998, 0.937, and 0.802, respectively. A coincidence greater than 0.7 between the aneurysms predicted by the model and the ground truth was considered as a true positive. For IAs detection, the sensitivity reached 90.63% with 0.58 false positives per case. The volume of IAs segmented by our model showed a high agreement and consistency with the volume of IAs labeled by experts. CONCLUSION: The deep learning framework is achievable and robust for IAs segmentation and detection. Our model offers more clinical application opportunities compared to digital subtraction angiography (DSA)-based, CTA-based, and MRA-based methods. CLINICAL RELEVANCE STATEMENT: Our deep learning framework effectively detects and segments intracranial aneurysms using clinical routine T1 sequences, showing remarkable effectiveness and offering great potential for improving the detection of latent intracranial aneurysms and enabling early identification. KEY POINTS: •There is no segmentation method based on clinical routine T1 images. Our study shows that the proper deep learning framework can effectively localize the intracranial aneurysms. •The T1-based segmentation and detection method is more universal than other angiography-based detection methods, which can potentially reduce missed diagnoses caused by the absence of angiography images. •The deep learning framework is robust and has the potential to be applied in a clinical setting.

Circadian rhythm and aneurysmal subarachnoid hemorrhage: Is there an alarm clock for the rupture timing?

BACKGROUND AND PURPOSE: Data on the temporal distribution of the bleeding time of intracranial aneurysms are limited to a few small studies. With this study, the aim was to analyze time patterns of the occurrence of aneurysmal subarachnoid hemorrhage (SAH), particularly focusing on the impact of patients' socio-demographic and clinical characteristics on the ictus timing. METHODS: The study is based on an institutional SAH cohort with 782 consecutive cases treated between January 2003 and June 2016. Data were collected on the ictus time, patients' socio-demographic and clinical characteristics, as well as the initial severity and outcome. Univariate and multivariate analyses were performed on the bleeding timeline. RESULTS: There were two peaks in the circadian rhythm of SAH, one in the morning (7-9 a.m.) and the other in the evening (7-9 p.m.). The strongest alterations in the bleeding time patterns were observed for weekdays, patients' age, sex and ethnicity. Individuals with chronic alcohol and painkiller consumption showed a higher bleeding peak between 1 and 3 p.m. Finally, the bleeding time showed no impact on the severity, clinically relevant complications and the outcome of SAH patients. CONCLUSIONS: This study is one of the very few detailed analyses of the impact of specific socio-demographic, ethnic, behavioral and clinical characteristics on the rupture timing of aneurysms. Our results point to the possible relevance of the circadian rhythm for the rupture event, and therefore might be useful in the elaboration of preventive measures against aneurysm rupture.

Small intracranial aneurysms of the anterior circulation: A negligible risk?

BACKGROUND AND PURPOSE: According to the International Study of Unruptured Intracranial Aneurysms, small (<7 mm) unruptured intracranial aneurysms (IAs) of the anterior circulation (aC) carry a neglectable 5-year rupture risk. In contrast, some studies report frequencies of >20% of all ruptured IAs being small IAs of the aC. This contradiction was addressed in this study by analyzing the rates and risk factors for rupture of small IAs within the aC. METHODS: Of the institutional observational cohort, 1676 small IAs of the aC were included. Different demographic, clinical, laboratory, and radiographic characteristics were collected. A rupture risk score was established using all independent prognostic factors. The score performance was checked using receiver operating characteristic curve analysis. RESULTS: Of all registered small IAs of the aC, 20.1% were ruptured. The developed small IAs of the aC (SIAAC) score (range = -4 to +13 points) contained five major risk factors: IA location and size, arterial hypertension, alcohol abuse, and chronic renal failure. In addition, three putative protective factors were also included in the score: hypothyroidism, dyslipidemia, and peripheral arterial disease. Increasing rates of ruptured IA with increasing SIAAC scores were observed, from 0% (≤-1 points) through >50% (≥8 points) and up to 100% in patients scoring ≥12 points. The SIAAC score achieved excellent discrimination (area under the curveSIAAC  = 0.803) and performed better than the PHASES (Population,Hypertension, Age, Size of the aneurysm, Earlier SAH from another aneurysm, Site of aneurysm) score. CONCLUSIONS: Small IAs of the aC carry a considerable rupture risk. After external validation, the proposed rupture risk score might provide a basis for better decision-making regarding the treatment of small unruptured IAs of the aC.

Rupture discrimination of multiple small (< 7 mm) intracranial aneurysms based on machine learning-based cluster analysis.

BACKGROUND: Small multiple intracranial aneurysms (SMIAs) are known to be more prone to rupture than are single aneurysms. However, specific recommendations for patients with small MIAs are not included in the guidelines of the American Heart Association and American Stroke Association. In this study, we aimed to evaluate the feasibility of machine learning-based cluster analysis for discriminating the risk of rupture of SMIAs. METHODS: This multi-institutional cross-sectional study included 1,427 SMIAs from 660 patients. Hierarchical cluster analysis guided patient classification based on patient-level characteristics. Based on the clusters and morphological features, machine learning models were constructed and compared to screen the optimal model for discriminating aneurysm rupture. RESULTS: Three clusters with markedly different features were identified. Cluster 1 (n = 45) had the highest risk of subarachnoid hemorrhage (SAH) (75.6%) and was characterized by a higher prevalence of familiar IAs. Cluster 2 (n = 110) had a moderate risk of SAH (38.2%) and was characterized by the highest rate of SAH history and highest number of vascular risk factors. Cluster 3 (n = 505) had a relatively mild risk of SAH (17.6%) and was characterized by a lower prevalence of SAH history and lower number of vascular risk factors. Lasso regression analysis showed that compared with cluster 3, clusters 1 (odds ratio [OR], 7.391; 95% confidence interval [CI], 4.074-13.150) and 2 (OR, 3.014; 95% CI, 1.827-4.970) were at a higher risk of aneurysm rupture. In terms of performance, the area under the curve of the model was 0.828 (95% CI, 0.770-0.833). CONCLUSIONS: An unsupervised machine learning-based algorithm successfully identified three distinct clusters with different SAH risk in patients with SMIAs. Based on the morphological factors and identified clusters, our proposed model has good discrimination ability for SMIA ruptures.