OBJECTIVE:This study was performed to clarify the clinical and radiological features of patients with moyamoya disease under 4 years of age in Japan. METHODS:For this retrospective multicenter cohort study, the MACINTOSH Study (Moyamoya Disease with Aggressive Clinical Course in Infants for Safety and Healthy Growth Study), patients were included if they were younger than 4 years of age, were hospitalized due to transient ischemic attack (TIA) or stroke between January 2008 and December 2018, and had a diagnosis of moyamoya disease or moyamoya syndrome. Patient clinical and radiological data were collected between January 1, 2021, and December 31, 2021. A Central Judgement Committee performed blind evaluations of imaging studies. RESULTS:Seventy-one patients were included in the study, 31 males and 40 females, whose mean age was 29.7 ± 12.7 months (0-47 months). Patients under 1 year of age had a strong male predominance (p = 0.0344) and no family history of moyamoya disease. Clinical diagnosis at disease onset included TIA (n = 31) and ischemic stroke (n = 40). All patients under 1 year of age presented with ischemic stroke. Among all the patients with ischemic stroke, seizure occurred at a mean age of 11.8 ± 9.9 months compared with 29.5 ± 11.7 months in those without ischemic stroke (p < 0.001). Most patients (69/71) had a diagnosis of bilateral moyamoya disease. Suzuki disease stage 2 was the most frequent (53/142 hemispheres). Among the 140 diseased hemispheres, 79 had cerebral infarcts, which were categorized as watershed zone infarcts (n = 64) and branch territory infarcts (n = 15). The branch territory infarcts were most frequently observed in Suzuki stage 2 hemispheres. CONCLUSIONS:This study demonstrated that demographic, clinical, and radiological characteristics are very specific in patients with moyamoya disease under 4 years of age, especially those under 1 year. Even a very early disease stage (Suzuki stage 2) could provoke TIA and/or ischemic stroke through the mechanism of artery-to-artery embolism as well as hemodynamic ischemia. Clinical trial registration no.: UMIN000040169 (www.umin.ac.jp).

Multidelay arterial spin labeling (ASL) MRI requires balancing temporal information with signal-to-noise ratio (SNR). A hybrid scheme combines the high SNR of time-encoded pseudo-continuous ASL (PCASL) with the temporal flexibility of variable-TR PCASL. The purpose of the present study was to assess the SNR and quantitative performance of the hybrid scheme by comparing it to time-encoded and variable-TR schemes for evaluating cerebral perfusion in patients with moyamoya disease. Twenty patients with moyamoya disease (8 men and 12 women, 27.6 ± 22.7 years) were scanned with 3 T MRI system. Variable-TR PCASL with 12 delays (vTR12), time-encoded PCASL with seven delays (TEnc7), and hybrid PCASL with 12 (4 × 3) delays (Hyb12) were obtained. Hyb12 and vTR12 were configured with nearly identical label duration (LD) and postlabeling delay (PLD) settings. For TEnc7, it was balanced so that the maximum LD + PLD time is the same. Time-corrected SNR (SNRt), cerebral blood flow (CBF), and arterial transit time (ATT) were measured in vascular territories within gray matter. The three parameters were compared using the Friedman's matched test, followed by the Dunn's multiple comparison test. Correlations were evaluated with Pearson's correlation, and agreement was assessed by Bland-Altman plot analysis and intraclass correlation coefficient (ICC). The SNRt of Hyb12 (4.67 ± 1.97) was significantly higher than that of vTR12 (3.27 ± 1.37, p < 0.0001) and TEnc7 (3.52 ± 1.32, p < 0.0001). The CBF of Hyb12 (49.9 ± 13.7 mL/100 g/min) was significantly lower than that of vTR12 (54.9 ± 15.4 mL/100 g/min, p < 0.0001) and TEnc7 (57.5 ± 15.9 mL/100 g/min, p < 0.0001). The ATT of Hyb12 (1240 ± 430 ms) was significantly shorter than that of vTR12 (1474 ± 419 ms, p < 0.0001) and TEnc7 (1402 ± 333 ms, p < 0.0001). CBF and ATT measurements from Hyb12 showed strong correlations and good agreement with the other two schemes. The hybrid scheme offers higher SNRt than both time-encoded and variable-TR schemes, which may improve the accuracy of cerebral perfusion assessment in patients with cerebral artery occlusive diseases, where delayed blood flow is a concern.

This study aimed to elucidate the anatomical characteristics of the ascending pharyngeal artery (APhA) using three-dimensional rotational angiography (3D-RA) and its role in preventing complications during carotid endarterectomy (CEA). Data from 279 primary CEAs (259 patients; median age, 73 years; male/female ratio, 6.2:1) conducted between 2006 and 2022 at a single center were retrospectively analyzed. The APhA anatomy was evaluated using carotid 3D-RA. The APhA was identified on 3D-RA in 277 of 279 carotid arteries (99.3

OBJECTIVE Plaque composition, but not degree of stenosis, may play a key role in the development of recurrent ischemic events in patients with symptomatic mild (< 50%) carotid artery stenosis. This multicenter prospective cohort study was aimed to determine their clinical and radiological features and to evaluate the benefits of carotid endarterectomy (CEA) for them. METHODS This study included 124 patients with cerebrovascular or retinal ischemic events ipsilateral to mild carotid stenosis. Best medical therapy (BMT) was administered to all participants. CEA or carotid artery stenting was implemented at each institution’s discretion. Baseline and 6-, 12-, and 24-month follow-up data were collected. The primary endpoint was ipsilateral ischemic stroke. Secondary endpoints included any stroke, ipsilateral transient ischemic attack, ipsilateral ocular symptoms, any death, and plaque progression requiring CEA/carotid artery stenting. The multivariate Cox proportional hazards model was used to evaluate the predictors for each endpoint. RESULTS Of 124 patients, 70 (56.5%) had a history of ipsilateral ischemic stroke and 51 (43.5%) had been treated with antiplatelet agents. The mean (± SD) degree of stenosis was 22.4% ± 13.7%. Plaque composition was categorized as fibrous plaque in 22 patients, lipid-rich or necrotic core in 25, and intraplaque hemorrhage (IPH) in 69. BMT was indicated for 59 patients, and CEA was performed in 63. The incidence of primary endpoint was significantly higher in the BMT group than in the CEA group (15.1% vs 1.7%; HR 0.18; 95% CI 0.05–0.84; p = 0.03). The predictors for primary endpoint were CEA (HR 0.18; 95% CI 0.05–0.84; p = 0.03) and IPH (HR 1.92; 95% CI 1.26–4.28; p = 0.04). The incidence of secondary endpoint was significantly higher in the BMT group than in the CEA group (31.4% vs 7.3%; HR 0.32; 95% CI 0.13–0.79; p = 0.01). The predictors for secondary endpoints were also CEA (HR 0.32; 95% CI 0.13–0.79; p = 0.01) and IPH (HR 1.52; 95% CI 1.06–4.39; p = 0.03). CONCLUSIONS IPH may highly predict subsequent cerebrovascular events, whereas CEA may reduce these risks during a 2-year follow-up in patients with symptomatic mild carotid stenosis.

Treatment options for cerebral infarction beyond the time window of reperfusion therapy are limited, and novel approaches are needed. PDGF-B is considered neuroprotective; however, it is difficult to administer at effective concentrations to infarct areas. Nanoparticles (NPs) are small and stable; therefore, we modified PDGF-B to the surface of naturally occurring heat shock protein NPs (HSPNPs) to examine its therapeutic effect in cerebral infarction. PDGF-B modified HSPNPs (PDGF-B HSPNPs) were injected 1 d after transient middle cerebral artery occlusion (t-MCAO) in CB-17 model mice. We analyzed the infarct volume and motor functional recovery at 3 and 7 d. PDGF-B HSPNPs were specifically distributed in the infarct area, and compared with HSPNPs alone, they significantly reduced infarct volumes and improved neurologic function 3 and 7 d after administration. PDGF-B HSPNP administration was associated with strong phosphorylation of Akt in infarct areas and significantly increased neurotrophin (NT)-3 production as well as reduced cell apoptosis compared with HSPNPs alone. Moreover, astrogliosis in peri-infarct area was significantly upregulated with PDGF-B HSPNPs compared with HSPNPs alone. Treatment with PDGF-B HSPNPs might be a novel approach for treating cerebral infarction.

Moyamoya disease (MMD) is characterized by progressive arterial occlusion, causing chronic hemodynamic impairment, which can reduce brain volume. A novel quantitative technique, synthetic magnetic resonance imaging (SyMRI), can evaluate brain volume. This study aimed to investigate whether brain volume measured with SyMRI correlated with cerebral blood flow (CBF) and brain function in adult MMD. In this retrospective study, 18 adult patients with MMD were included. CBF was measured using iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography. Cerebrovascular reactivity (CVR) to acetazolamide challenge was also evaluated. Brain function was measured using the Wechsler Adult Intelligence Scales (WAIS)-III/IV and the WAIS-R tests. Gray matter (GM), white matter, and myelin-correlated volumes were evaluated in six areas. Resting CBF was positively correlated with GM fractions in the right anterior cerebral arterial and right middle cerebral arterial (MCA) territories. CVR was positively correlated with GM fraction in the right posterior cerebral arterial (PCA) territory. Full-Scale Intelligence Quotient and Verbal Comprehension Index scores were marginally positively correlated with GM fractions in the left PCA territory. Processing Speed Index score was marginally positively correlated with GM fraction in the right MCA territory. The SyMRI-measured territorial GM fraction correlated with CBF and brain function in patients with MMD.

OBJECTIVE:Rupture of cerebral aneurysms has a poor prognosis, and growing aneurysms are prone to rupture. Although the number of coil embolization procedures is increasing worldwide, they are more prone to recurrence than clipping surgeries. However, there is still no drug that prevents aneurysm growth or recanalization after coil embolization. The authors have previously focused on the role of hemodynamics in cerebral aneurysm development and reported that inhibition of the P2X4 purinoceptor, by which vascular endothelial cells sense blood flow, reduced the induction and growth of aneurysms in an animal model. In this study, the authors investigated the effects of paroxetine, a P2X4 inhibitor also used as an antidepressant, on aneurysm growth and recanalization after endovascular coiling. METHODS:Using the J-ASPECT Study registry, the largest comprehensive reimbursement database system for acute stroke inpatient care in Japan, the authors searched for patients incidentally taking paroxetine who were registered in the decade 2010-2019 with an unruptured cerebral aneurysm or who underwent aneurysm coiling. They calculated the growth incidence and growth rate by the person-year method and the odds ratio for recanalization within 1 year after coiling and statistically compared to controls. RESULTS:Seventy-eight stroke facilities participated, and 275 patients were identified as potentially eligible. Thirty-seven patients with unruptured aneurysms and 38 after coil embolization met all eligibility criteria. They were compared with 396 control cases of unruptured aneurysms and 308 coil-placement controls. Multivariate analysis showed that paroxetine significantly reduced the incidence of aneurysm growth (number of cases with growth/person/year; incidence rate ratio [IRR] 0.24, 95% CI 0.05-0.66; p = 0.003) and the growth rate (total increase in maximum diameter in millimeters/person/year; IRR 0.57, 95% CI 0.28-0.98; p = 0.04). Paroxetine also significantly reduced the odds of recanalization in the year after coiling (OR 0.21, 95% CI 0.05-0.95; p = 0.04). The authors then performed propensity score matching to reduce bias due to imbalances in patient characteristics between the two groups; the outcome confirmed that paroxetine significantly reduced aneurysm growth incidence (IRR 0.02, 95% CI 0.008-0.05; p < 0.0001) and growth rate (IRR 0.03, 95% CI 0.01-0.06; p < 0.0001) and the 1-year recanalization (OR 0.18, 95% CI 0.03-0.99; p = 0.04). CONCLUSIONS:This observational cohort study suggests that P2X4 inhibitors such as paroxetine may be clinically applicable as prophylaxis against aneurysm rupture and postoperative recanalization.

Ruptured cerebral aneurysms have a higher incidence of direct surgery-related adverse events compared to unruptured aneurysms owing to challenging surgical conditions, such as difficulties in surgical exposure, cerebral edema, and intraoperative aneurysmal rupture, that increase the intraprocedural difficulty. The most common surgical adverse event is intraoperative rupture, with uncontrolled ruptures(during pre-dissection or from a tear in the aneurysm neck) often resulting in poor clinical outcomes. The key strategies for intraoperative rupture include staying calm, controlling bleeding, and ensuring hemostasis through appropriate methods. Given the advances in endovascular therapy for intracranial aneurysms, the number of microsurgical procedures has been decreasing. Thus, neurosurgeons at each facility need to prepare and gain experience in handling intraoperative ruptures.

Angiogenic factors associated with Moyamoya disease (MMD) are overexpressed in M2 polarized microglia in ischemic stroke, suggesting that microglia may be involved in the pathophysiology of MMD; however, existing approaches are not applicable to explore this hypothesis. Herein we applied blood induced microglial-like (iMG) cells. We recruited 25 adult patients with MMD and 24 healthy volunteers. Patients with MMD were subdivided into progressive (N = 7) or stable (N = 18) group whether novel symptoms or radiographic advancement of Suzuki stage within 1 year was observed or not. We produced 3 types of iMG cells; resting, M1-, and M2-induced cells from monocytes, then RNA sequencing followed by GO and KEGG pathway enrichment analysis and qPCR assay were performed. RNA sequencing of M2-induced iMG cells revealed that 600 genes were significantly upregulated (338) or downregulated (262) in patients with MMD. Inflammation and immune-related factors and angiogenesis-related factors were specifically associated with MMD in GO analysis. qPCR for MMP9 , VEGFA , and TGFB1 expression validated these findings. This study is the first to demonstrate that M2 microglia may be involved in the angiogenic process of MMD. The iMG technique provides a promising approach to explore the bioactivity of microglia in cerebrovascular diseases.

Arterial spin labeling (ASL) is a noninvasive imaging technique that labels the proton spins in arterial blood and uses them as endogenous tracers. Brain perfusion imaging with ASL is becoming increasingly common in clinical practice, and clinical applications of ASL for intracranial magnetic resonance angiography (MRA) have also been demonstrated. Unlike computed tomography (CT) angiography and cerebral angiography, ASL-based MRA does not require contrast agents. ASL-based MRA overcomes most of the disadvantages of time-of-flight (TOF) MRA. Several schemes have been developed for ASL-based MRA; the most common method has been pulsed ASL, but more recently pseudo-continuous ASL, which provides a higher signal-to-noise ratio (SNR), has been used more frequently. New methods that have been developed include direct intracranial labeling methods such as velocity-selective ASL and acceleration-selective ASL. MRA using an extremely short echo time (eg, silent MRA) or ultrashort echo-time (TE) MRA can suppress metal susceptibility artifacts and is ideal for patients with a metallic device implanted in a cerebral vessel. Vessel-selective 4D ASL MRA can provide digital subtraction angiography (DSA)-like images. This review highlights the principles, clinical applications, and characteristics of various ASL-based MRA techniques. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Background: The number of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in elderly patients has increased, but the feasibility and safety are still debated. We aimed to investigate the risk factors and produce a prognostic scoring system for MT in elderly AIS patients. Methods: We analyzed data from 763 consecutive patients who underwent MT for AIS between January 2013 and January 2020 at seven comprehensive stroke centers for derivation group. We defined elderly patients as ≥ 75 years of age. We investigated the risk factors of MT among these elderly patients and developed a prognostic scoring system assigned weighted points proportional to their standardized coefficient values. We conducted a subsequent validation study that included 287 consecutive patients treated between February 2020 and December 2021. Results: In total, 251 elderly patients in derivation group were analyzed retrospectively. According to the multivariable analysis, we developed a scoring system (SNA 3 P score) consisting of six factors, including age ≥ 90 (2 points), female sex (2 points), a pre-modified Rankin Scale (mRS) score of 2 (1 point), anticoagulant drug use (2 points), the NIHSS score (4 points), and the ASPECTS (4 points). A score ≤ 5 predicted an mRS score of 0-2 at 90 days with a sensitivity of 74% and a specificity of 65%, and the area under the curve (AUC) was 0.76. In the validation study, a score ≤ 5 predicted an mRS score of 0-2 at 90 days with a sensitivity of 70% and a specificity of 60% (AUC was 0.74). Conclusions: We created the novel scoring system to predict the functional outcome of elderly AIS patients undergoing MT. This simple scoring system may provide the information for indication of MT for elderly AIS patients, but further investigation for external validation is needed.

Objectives To examine the national, 6-year trends in in-hospital clinical outcomes of patients with subarachnoid haemorrhage (SAH) who underwent clipping or coiling and the prognostic influence of temporal trends in the Comprehensive Stroke Center (CSC) capabilities on patient outcomes in Japan.Design Retrospective study.Setting Six hundred and thirty-one primary care institutions in Japan.Participants Forty-five thousand and eleven patients with SAH who were urgently hospitalised, identified using the J-ASPECT Diagnosis Procedure Combination database.Primary and secondary outcome measures Annual number of patients with SAH who remained untreated, or who received clipping or coiling, in-hospital mortality and poor functional outcomes (modified Rankin Scale: 3–6) at discharge. Each CSC was assessed using a validated scoring system (CSC score: 1–25 points).Results In the overall cohort, in-hospital mortality decreased (year for trend, OR (95% CI): 0.97 (0.96 to 0.99)), while the proportion of poor functional outcomes remained unchanged (1.00 (0.98 to 1.02)). The proportion of patients who underwent clipping gradually decreased from 46.6% to 38.5%, while that of those who received coiling and those left untreated gradually increased from 16.9% to 22.6% and 35.4% to 38%, respectively. In-hospital mortality of coiled (0.94 (0.89 to 0.98)) and untreated (0.93 (0.90 to 0.96)) patients decreased, whereas that of clipped patients remained stable. CSC score improvement was associated with increased use of coiling (per 1-point increase, 1.14 (1.08 to 1.20)) but not with short-term patient outcomes regardless of treatment modality.Conclusions The 6-year trends indicated lower in-hospital mortality for patients with SAH (attributable to better outcomes), increased use of coiling and multidisciplinary care for untreated patients. Further increasing CSC capabilities may improve overall outcomes, mainly by increasing the use of coiling. Additional studies are necessary to determine the effect of confounders such as aneurysm complexity on outcomes of clipped patients in the modern endovascular era.

The authors have requested that this preprint be removed from Research Square.

Purpose Accurate assessment of cerebral perfusion in moyamoya disease is necessary to determine the indication for treatment. We aimed to investigate the usefulness of dynamic PCASL using a variable TR scheme with optimized background suppression in the evaluation of cerebral perfusion in moyamoya disease. Methods We retrospectively analyzed the images of 24 patients (6 men and 18 women, mean age 31.4 ± 18.2 years) with moyamoya disease; each of whom was imaged with both dynamic PCASL using the variable-TR scheme and 123 IMP SPECT with acetazolamide challenge. ASL dynamic data at 10 phases are acquired by changing the LD and PLD. The background suppression timing was optimized for each phase. CBF and ATT were measured with ASL, and CBF and CVR to an acetazolamide challenge were measured with SPECT. Results A significant moderate correlation was found between the CBF measured by dynamic PCASL and that by SPECT ( r = 0.53, P < 0.001). The CBF measured by dynamic PCASL (52.5 ± 13.3 ml/100 mg/min) was significantly higher than that measured by SPECT (43.0 ± 12.6 ml/100 mg/min, P < 0.001). The ATT measured by dynamic PCASL showed a significant correlation with the CVR measured by SPECT ( r = 0.44, P < 0.001). ATT was significantly longer in areas where the CVR was impaired (CVR < 18.4%, ATT = 1812 ± 353 ms) than in areas where it was preserved (CVR > 18.4%, ATT = 1301 ± 437 ms, P < 0.001). The ROC analysis showed a moderate accuracy (AUC = 0.807, sensitivity = 87.7%, specificity = 70.4%) when the cutoff value of ATT was set at 1518 ms. Conclusion Dynamic PCASL using this scheme was found to be useful for assessing cerebral perfusion in moyamoya disease.

BACKGROUND:Long-term outcomes after surgical treatment of arachnoid cysts (ACs) have not been reported adequately. Impaired visual acuity is not a common symptom of shunt dependency syndrome due to cyst-peritoneal (CP) shunt malfunction for ACs. We report a case of CP shunt malfunction, who presented only impaired visual acuity as a symptom, long after the initial surgical treatment.CASE DESCRIPTION:A 16-year-old boy was surgically treated for the left frontal AC with CP shunting at 2 years of age. Extension of the peritoneal shunt catheter was performed at 15 years of age. A year later, he started experiencing impairment of visual acuity without headaches, which worsened to bilateral light perception. The presence of bilateral optic atrophy was confirmed. The AC in the left frontal lobe had enlarged very slightly, with shortening of the intracystic catheter, and the cerebrospinal fluid pressure was elevated to 30 cmH2O. He was treated with lumboperitoneal shunting. The visual acuity showed limited improvement.CONCLUSION:The possibility of CP shunt malfunction and shunt dependency syndrome should be considered, even if the patient presented only impaired visual acuity and no significant changes in the size of the ACs are observed.

hemorrhage, aneurysm, Takayasu arteritis, autopsy artery, Oph: ophthalmic artery, Oc: occlusion, St: stenosis Abstract We report an autopsy case of 42-year-old man with Takayasu arteritis and subarachnoid hemorrhage due to ruptured anterior communicating artery aneurysm. Radiological imaging study revealed total occlusion of left common carotid artery and left subclavian artery. Renal hypertension was also pointed out. The patient was treated with long-term therapy of corticosteroids, and vasculitis had been controlled. Autopsy findings revealed severe subarachnoid hemorrhage due to ruptured saccular aneurysms at the anterior communicating artery. No vasculitis, atherosclerosis, or dissection was observed at the intracranial arteries and the aneurysmal walls. The histological findings of the large-sized arteries were compatible with Takayasu arteritis. Although left common carotid artery was almost completely occluded, left internal carotid artery was patent. There were 22 case reports of subarachnoid hemorrhage due to ruptured aneurysm complicated with Takayasu arteritis. These papers reported that the aneurysms were more common in the posterior circulation and that one or more of the cervical arteries showed stenosis or occlusion in most cases. Aneurysmal formation due to hemodynamic mechanism is generally considered, but spread of inflammatory changes to the intracranial blood vessels has also been reported. The antiplatelet therapy for Takayasu arteritis is recommended to prevent thrombosis, and the condition of patients is often complicated with hypertension. Since aneurysmal formation at the cerebral arteries is not a rare complication and fatal subarachnoid hemorrhage may occur, periodic head imaging tests may be recommended and reconstructive vascular operation may be considered in certain cases.

BACKGROUND Cerebrovascular events and infection are among the most common complications of left ventricular assist device (LVAD) therapy. The authors reported on a patient with an infectious intracranial aneurysm (IIA) associated with LVAD infection that was successfully occluded by endovascular therapy. OBSERVATIONS A 37-year-old man with severe heart failure received an implantable LVAD. He was diagnosed with candidemia due to driveline infection 44 months after LVAD implantation, and empirical antibiotic therapy was started. After 4 days of antibiotic treatment, the patient experienced sudden dizziness. Computed tomography (CT) revealed subarachnoid hemorrhage in the right frontal lobe, and CT angiography revealed multiple aneurysms in the peripheral lesion of the anterior cerebral artery (ACA) and middle cerebral artery. Two weeks and 4 days after the first bleeding, aneurysms on the ACA reruptured. Each aneurysm was treated with endovascular embolization using n-butyl cyanoacrylate. Subsequently, the patient had no rebleeding of IIAs. The LVAD was replaced, and bloodstream infection was controlled. He received a heart transplant and was independent 2 years after the heart transplant. LESSONS LVAD-associated IIAs have high mortality and an increased risk of surgical complications. However, endovascular obliteration may be safe and thus improve prognosis.

BACKGROUND AND PURPOSE: An accurate assessment of the hemodynamics of an intracranial dural AVF is necessary for treatment planning. We aimed to investigate the utility of 4D-MRA based on superselective pseudocontinuous arterial spin-labeling with CENTRA-keyhole and view-sharing (4D-S-PACK) for the vessel-selective visualization of intracranial dural AVFs. MATERIALS AND METHODS: We retrospectively analyzed the images of 21 patients (12 men and 9 women; mean age, 62.2 [SD,19.2]?years) with intracranial dural AVFs, each of whom was imaged with DSA, 4D-S-PACK, and nonselective 4D-MRA based on pseudocontinuous arterial spin-labeling combined with CENTRA-keyhole and view-sharing (4D-PACK). The shunt location, venous drainage patterns, feeding artery identification, and Borden classification were evaluated by 2 observers using both MRA methods on separate occasions. Vessel selectivity was evaluated on 4D-S-PACK. RESULTS: Shunt locations were correctly evaluated in all 21 patients by both observers on both MRA methods. With 4D-S-PACK, observers 1 and 2 detected 76 (80.0%, P?<?.001) and 73 (76.8%, P?<?.001) feeding arteries of the 95 feeding arteries identified on DSA but only 39 (41.1%) and 46 (48.4%) feeding arteries with nonselective 4D-PACK, respectively. Both observers correctly identified 10 of the 11 patients with cortical venous reflux confirmed by DSA with both 4D-S-PACK and 4D-PACK (sensitivity?= 90.9%, specificity?= 90.9% for each method), and they made accurate Borden classifications in 20 of the 21 patients (95.2%) on both MRA methods. Of the 84 vessel territories examined, vessel selectivity was graded 3 or 4 in 73 (91.2%) and 66 (88.0%) territories by observers 1 and 2, respectively. CONCLUSIONS: 4D-S-PACK is useful for the identification of feeding arteries and accurate classifications of intracranial dural AVFs and can be a useful noninvasive clinical tool.

Background and Purpose: Japan has a rapidly aging population and the application of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) among elderly patients has increased, but feasibility and safety of MT for elderly patients are still debated. Therefore, this study aimed to elucidate feasibility and safety of MT by analyzing the retrospective multicenter database. Methods: A total of 763 consecutive patients who underwent MT for AIS between January 2013 and January 2020 at six comprehensive stroke centers were enrolled in this study. We analyzed elderly AIS patients defined as those aged ≥ 75 years with IC/M1/M2 occlusion. Good outcome was defined mRS 0-2 at 90 days after onset, and we investigated the factors associated with good outcome. Results: A total of 523 patients with IC/M1/M2 occlusion were analyzed, of which 316 were elderly (52%). Good outcome was significantly decreased in elderly AIS patients compared with non-elderly patients (35 % vs 56 %, p=0.0007). Among the elderly AIS patients, aged < 90 years, male sex, NIH stroke scale, prior administration of anticoagulants, mRS before onset, ASPECTS, M2 occlusion, and dyslipidemia were associated with good outcome with multivariable analysis. An elderly AIS prognostic scoring system (eAIS-PSS) was set up based on these factors , and the areas under the curves (AUC) was 0.78 at the optimal cut-off value of 7 / 22 with this scoring system. eAIS-PSS predicted good outcome with a sensitivity of 72% and a specificity of 75%. Conclusion: eAIS-PSS was useful to predict good outcome in MT for elderly AIS patients.