Mechanical thrombectomy is efficacious in patients with pre-stroke moderate disability.

INTRODUCTION: Patients with ischaemic stroke due to large vessel occlusion (LVO) can be treated successfully with mechanical thrombectomy (MT) and/or intravenous thrombolysis. In the landmark trials, MT was only performed for those with no functional disability prior to stroke (mRS 0-2). There are limited data available regarding clinical outcomes for patients with pre-stroke moderate disability (mRS ≥ 3). The aims of this study were to analyse the clinical outcomes and financial implications in regard to accommodation costs of performing MT in patients with pre-stroke mRS = 3. METHODS: An observational cohort study was performed of 802 patients with anterior circulation LVO ischaemic stroke who underwent MT between October 2016 and January 2020 at three tertiary hospitals. Patient demographics, premorbid mRS, stroke and interventional data, 90-day mRS and accommodation situation were recorded. RESULTS: Eighty-two patients with anterior circulation LVO ischaemic stroke were pre-stroke mRS 3. 38% had a good clinical outcome, as defined by mRS 3 at 90 days. Mortality rate was 38%. The majority of patients presented from home (83%) and greater than one third of those returned home during the 90 days post treatment. 81% of patients had no increase in accommodation cost at 90 days. CONCLUSION: Patients with pre-stroke moderate disability may benefit from MT if they are appropriately selected. This may result in fewer patients requiring nursing home placement and less financial burden on the public health system, indicating significant savings are possible.

Transradial versus transfemoral access for anterior circulation mechanical thrombectomy: analysis of 375 consecutive cases.

OBJECTIVE: To compare transradial artery access (TRA) to the gold standard of transfemoral artery access (TFA) in mechanical thrombectomy (MT) for stroke caused by anterior circulation large vessel occlusion. METHODS: The clinical outcomes, procedural speed, angiographic efficacy and safety of both techniques were analysed in 375 consecutive cases over an 18-month period in a high volume statewide neurointerventional service. RESULTS: There was no significant difference in patient characteristics, stroke parameters, imaging techniques or intracranial techniques. The median time elapsed between CT scanning and reperfusion was 96.5 min (IQR 68-123) in the TFA group and 95 min (IQR 68-123) in the TRA group (p=0.456). Of 336 patients who were independent at presentation 58% (124/214) of the TFA group and 67% (82/122) of the TRA group had a modified Rankin score of 0-2 at 90-day follow-up (p=0.093). Cross-over from radial to femoral was 4.6% (4/130) compared with 1.6% cross-over from femoral to radial (4/245), but did not meet the predetermined level of statistical significance (OR 2.92, 95% CI 0.81 to 10.52), p=0.088) and did not impact median procedural speed. Adequate angiographic reperfusion, first pass reperfusion, embolisation to new territory and symptomatic intracranial haemorrhage were similar in both groups. There was a significant difference in major access site complications requiring an additional procedure. None of the TRA cases had a major access site complication but 6.5% (16/245) of the TFA cases did (p=0.003). CONCLUSION: This study suggests that using TRA for anterior circulation MT is fast, efficacious, safe and not inferior to the gold standard of TFA.

First line transradial access for posterior circulation stroke intervention; initial 12-month experience at a high volume thrombectomy center.

BACKGROUND: The Neurointerventional Surgery Standards and Guidelines Committee has advocated the use of transradial access in the setting of posterior circulation stroke intervention, however there is a paucity of published data on this approach. The purpose of this study is to present 12-months of prospectively collected data from a high volume thrombectomy center following the adoption of a first line transradial approach for posterior circulation stroke intervention. METHODS: A range of data on patient characteristics, procedural metrics, complications and outcomes was prospectively collected between August 2018 - August 2019 following the adoption of first line transradial access for posterior circulation stroke intervention at a high volume thrombectomy center. RESULTS: Transradial access was successful in 22/23 cases (96%), median arteriotomy to reperfusion time was 24 min (IQR 18-40), good angiographic outcome (mTICI 2b-3) was achieved in all cases and good clinical outcome (mRs 0-2) was achieved in 61% of cases. No intracranial or radial artery access site complications occurred. CONCLUSION: The fast procedure times, excellent outcomes and low complication rates achieved in this prospective 12-month study indicate that transradial access is a viable first line strategy in posterior circulation stroke intervention.

Future Directions of Flow Diverter Therapy.

The treatment of intracranial aneurysms has undergone a few very significant paradigm shifts in its history. Needless to say, microsurgery and surgical clipping served as the initial basis for successful treatment of these lesions. The pursuit of endovascular therapy subsequently arose from the desire to reduce the invasiveness of therapy. While the first breakthrough arose with Guido Guglielmi's invention of the detachable platinum coil, commercialized flow diverter therapy represents a disruptive therapy with a completely different paradigm for aneurysmal obliteration. This has not only altered the distribution of aneurysmal management strategies, but also opened the gateway to the treatment of previously inoperable lesions. With the basic flow diverter stent technology now considered an integral part of the neurointerventional armamentarium, we now consider what may lay in the future - including potential directions for research with regards to case selection; the location and type of aneurysms which may become routinely treatable; and modifications to the flow diverter, which may increase its utility and safety in terms of size, structural design, and surface modifications.

Air retrieval for clot retrieval; time-metrics and outcomes of stroke patients from rural and remote regions air-transported for mechanical thrombectomy at a state stroke unit.

BACKGROUND: Providing thrombectomy services to rural or remote regions with small, dispersed populations presents a particular challenge. Sustaining local thrombectomy services is not viable given the low throughput of cases, therefore large vessel occlusion (LVO) stroke patients require emergent transfer, often by air, to the closest high volume urban thrombectomy unit. The aim of this paper is to present logistical, time-metric data and outcome data on LVO stroke patients that have been aeromedically retrieved for thrombectomy from the vast, 2,500,000-km2 rural catchment of the Western Australian state thrombectomy unit. METHODS: The prospectively collected state thrombectomy registry was reviewed and all patients that underwent thrombectomy for LVO strokes following aeromedical retrieval from remote or rural catchments were identified. Multiple logistic and time-metric data points were recorded and outcomes were compared to a cohort of urban patients treated over the same period. RESULTS: Over a 2-year period 30 patients underwent thrombectomy following aeromedical retrieval, either by helicopter or fixed wing aircraft, from rural and remote regions of Western Australia. The mean aeromedical retrieval distance was 393 km while the maximum retrieval distance was over 2600 km. The mean ictus to recanalization time was 657 min, an mTICI 2b-3 recanalization was achieved in 93% of cases and 62% of anterior circulation, and 50% of posterior circulation LVO stroke patients achieved functional independence at 90-days. Outcome data for rural patients compared favourably to urban patients treated over the same time period. CONCLUSION: With the availability of an efficient aeromedical retrieval service, LVO stroke patients in rural and remote regions can achieve excellent outcomes following transfer to a high volume thrombectomy unit, even if distances involved are very large.

Dual suction Headway27 microcatheter thrombectomy for the treatment of distal intracranial arterial occlusion strokes: initial experience with the micro-ADAPT technique.

BACKGROUND: Recent studies suggest that the proven benefits of endovascular thrombectomy (EVT) for the treatment of large vessel occlusion (LVO) strokes are transferable to more peripheral distal vessel occlusion (DVO) strokes under certain circumstances. Safely accessing and extracting these thrombi however remains challenging, particularly in more tortuous peripheral arteries. For such cases we have utilized the dual suction Headway27 microcatheter thrombectomy, or micro-ADAPT, technique with the aim of reducing potential trauma associated with negotiating stent retrievers or large bore aspiration catheters into the peripheral intracranial vasculature. We present our experience utilizing the micro-ADAPT in the treatment of DVO strokes. We describe our technique as well as present angiographic and clinical outcomes. METHODS: A retrospective review of our institution's prospectively collected EVT registry for the 12 months spanning July 2017 to June 2018 was undertaken. Data on all cases of micro-ADAPT EVT were collected and analyzed. RESULTS: Micro-ADAPT EVT was performed 14 times over the study period, with a recanalization rate of 79%. DVO strokes in multiple locations were treated, including the A3, M3, P3, and superior cerebellar artery. In cases where an LVO stroke was also present, the mean duration between primary LVO recanalization and secondary DVO micro-ADAPT recanalization was 15.5 min. No complications relating to the micro-ADAPT technique were recorded. No infarcts were present in the territory of the recanalized DVO stroke on day 1 CT in successful micro-ADAPT cases CONCLUSIONS: In the setting of challenging peripheral DVO strokes, the micro-ADAPT technique appears to be a fast and effective technique with a low complication rate.

Thrombectomy in stroke of unknown onset, wake up stroke and late presentations: Australian experience from 2 comprehensive stroke centres.

Two recent randomized controlled trials (RCTs) showed selected patients treated with endovascular thrombectomy (EVT) more than 6 h from acute ischemic stroke (AIS) onset had significant improvement in functional outcome at 90 days compared with standard care alone. Our aim is to determine the outcome and predictors of good outcome in AIS patients undergoing EVT with unknown-onset, or late presentation, stroke after 6 h from time last seen well, or witnessed stroke onset, at two Australian comprehensive stroke centres. A retrospective analysis of functional outcome and mortality at 90-days from a prospective cohort of 56 consecutive patients with unknown-onset, or late presentation, stroke with large vessel occlusion (LVO) in the anterior cerebral circulation undergoing EVT over a 15-month period (2016-2017). We evaluated factors which correlated with good functional outcome defined as a 90-day modified Rankin scale (mRS) 0-2. Recanalization times and symptomatic intracranial haemorrhage (sICH) rates were also examined. A good functional outcome was achieved in 35 patients (62%). Eight patients died (14%). Median time-to-recanalization was 7.6 h. SICH occurred in four patients (7%). Factors which predicted good 90-day functional outcome included baseline National Institutes of Health Stroke Scale (NIHSS) < 16, 24 h NIHSS < 10, baseline Alberta Stroke Program Early CT Score (ASPECTS) ≥ 8, pre-procedural CT perfusion imaging and LVO lesion location. This study shows good 'real world' outcomes, comparable to published RCTs, in patients with unknown-onset, or late presentation, stroke treated with EVT more than 6 h from stroke onset.

Transvenous coil embolization with intra-operative cone beam CT assistance in the treatment of hypoglossal canal dural arteriovenous fistulae.

BACKGROUND: Hypoglossal canal dural arteriovenous fistulae (HC-dAVF) are a rare subtype of skull base fistulae involving the anterior condylar confluence or anterior condular vein within the hypoglossal canal. Transvenous coil embolization is a preferred treatment strategy, however delineation of fistula angio-architecture during workup and localization of microcatheter tip during embolization remain challenging on planar DSA. For this reason, our group have utilized intra-operative cone beam CT (CBCT) and selective cone beam CT angiography (sCBCTA) as adjuncts to planar DSA during workup and treatment. The purpose of this article is to present our experience in the treatment of HC-dAVF using transvenous coil embolization (TVCE) with cone beam CT assistance, describing our technique as well as presenting our angiographic and clinical outcomes. METHODS: Ten patients with symptomatic HC-dAVF were treated using TVCE with intra-operative cone beam CT assistance. Prospectively collected data regarding clinical and angiographic results and complication rates was recorded and reviewed. RESULTS: Complication-free fistula occlusion was achieved in our entire patient cohort. The dominant symptom of pulsatile tinnitus resolved in all 10 patients. CONCLUSIONS: This study demonstrates that TVCE with CBCT assistance is a highly effective treatment option for HC-dAVF, achieving complication-free fistula occlusion in our entire patient cohort. We have found low-dose sCBCTA and CBCT to be an extremely useful adjunct to planar DSA imaging during both workup and treatment of these rare fistulae.

Direct endovascular thrombectomy and bridging strategies for acute ischemic stroke: a network meta-analysis.

OBJECTIVES: The present Bayesian network meta-analysis aimed to compare the various strategies for acute ischemic stroke: direct endovascular thrombectomy within the thrombolysis window in patients with no contraindications to thrombolysis (DEVT); (2) direct endovascular thrombectomy secondary to contraindications to thrombolysis (DEVTc); (3) endovascular thrombectomy in addition to thrombolysis (IVEVT); and (4) thrombolysis without thrombectomy (IVT). METHODS: Six electronic databases were searched from their dates of inception to May 2017 to identify randomized controlled trials (RCTs) comparing IVT versus IVEVT, and prospective registry studies comparing IVEVT versus DEVT or IVEVT versus DEVTc. Network meta-analyses were performed using ORs and 95% CIs as the summary statistic. RESULTS: We identified 12 studies (5 RCTs, 7 prospective cohort) with a total of 3161 patients for analysis. There was no significant difference in good functional outcome at 90 days (modified Rankin Scale score ≤2) between DEVT and IVEVT. There was no significant difference in mortality between all treatment groups. DEVT was associated with a 49% reduction in intracranial hemorrhage (ICH) compared with IVEVT (OR 0.51; 95% CI 0.33 to 0.79), due to reduction in rates of asymptomatic ICH (OR 0.47; 95% CI 0.29 to 0.76). Patients treated with DEVT had higher rates of reperfusion compared with IVEVT (OR 1.73; 95% CI 1.04 to 2.94). CONCLUSIONS: To our knowledge, this is the first network meta-analysis to be performed in the era of contemporary mechanical thrombectomy comparing DEVT and DEVTc. Our analysis suggests the addition of thrombolysis prior to thrombectomy for large vessel occlusions may not be associated with improved outcomes.

Entry remnants in flow-diverted aneurysms: Does branch geometry influence aneurysm closure?

OBJECTIVE: Numerous studies have suggested a relationship between delayed occlusion of intracranial aneurysms treated with the Pipeline Embolization Device (PED) and the presence of an incorporated branch. However, in some cases, flow diversion may still be the preferred treatment option. This study sought to determine whether geometric factors pertaining to relative size and angulation of branch vessel(s) can be measured in a reliable fashion and whether they are related to occlusion rates. METHODS: Eighty aneurysms treated at a single neurovascular center from November 2008 to June 2014 were identified. Two blinded raters prospectively reviewed the imaging performed at the time of the procedure and measured the following geometric variables: inflow jet/incorporated branch direction angle and branch artery/ parent artery ratio. Delayed occlusion was defined as the absence of complete aneurysmal occlusion at one year. Analysis was performed using logistic regression and intra-class correlation co-efficient (ICC). RESULTS: Twenty-four (30%) aneurysms with 28 incorporated branches were identified. A trend toward higher inflow jet/incorporated branch direction angle was found in the group of aneurysms demonstrating delayed occlusion when compared to the group with complete occlusion. ICC revealed high correlation. Overall lower one-year occlusion rates of 53% versus 73% for aneurysms with and without incorporated branches, respectively, were also noted. CONCLUSIONS: The presence of an incorporated branch conferred a 20% absolute risk increase for delayed aneurysmal occlusion. Incorporated branches with a larger angle between the inflow jet and the incorporated branch direction exhibited a trend toward lower occlusion rates. This might be further investigated using a multicenter approach in conjunction with other potentially relevant clinical and angiographic variables.

Embolization of cranial dural arteriovenous fistulas in the liquid embolic era: A Sydney experience.

Endovascular management of dural arteriovenous fistulas has become a mainstay of treatment. In particular, modern techniques have allowed greater fistula penetration and likelihood of complete obliteration. However, the efficacy of newer agents has not been quantified outside of predominantly small case reports and case series. Furthermore, the Australian experience with fistula embolization has yet to be reported in the literature. To this aim, we performed a retrospective review of our endovascular management of a large cohort of cranial dural arteriovenous fistulas in the liquid embolic era. This retrospective case series included ninety-six consecutive patients of any Cognard grade, treated between 2005 and 2016. Liquid embolic agents were used exclusively in eighty-three cases. The overall complete obliteration rate was 89.6% with a residual fistula rate of 2%, and complication rate of 8.3%. This Sydney, Australia cohort demonstrates excellent treatment effect and safety outcomes and thus supports the primary treatment of this condition by endovascular means.

The second-generation eCLIPs Endovascular Clip System: initial experience.

OBJECTIVE Treatment of wide-necked intracranial aneurysms is associated with higher recanalization and complication rates; however, the most commonly used methods are not specifically designed to work in bifurcation lesions. To address these issues, the authors describe the evolution in the design and use of the eCLIPs (Endovascular Clip System) device, a novel hybrid stent-like assist device with flow diverter properties that was first described in 2008. METHODS A registry was established covering 13 international centers at which patients were treated with the second-generation eCLIPs device. Aneurysm morphology and rupture status, device neck coverage, coil retention, and procedural and late morbidity and mortality were recorded. For those patients who had undergone successful implantation more than 6 months earlier, the final imaging and clinical follow-up results and need for re-treatment were recorded. RESULTS Thirty-three patients were treated between June 2013 and September 2015. Twenty-five (76%) patients had successful placement of an eCLIPs device; 23 (92%) of these 25 patients had complete data. Eight cases of nondeployment occurred during the 1st year of use, consistent with a learning curve; no failures of deployment occurred thereafter. Two periprocedural transient ischemic attacks and 2 asymptomatic thrombotic events occurred. Twenty-one (91%) of 23 patients underwent follow-up at an average of 8 months (range 3-18 months); 9 (42.9%) of these 21 patients demonstrated an improvement in Raymond grade at follow-up; no cases of worsening Raymond grade were recorded, and 17 (81.0%) patients sustained a modified Raymond-Roy Classification class of I or II angiographic result at follow-up. Two delayed ruptures were recorded, both in previously coiled, symptomatic giant aneurysms where the device was used as a part of a salvage strategy. CONCLUSIONS The second-generation eCLIPs device is a viable treatment option for bifurcation aneurysms. The aneurysm occlusion rates in this initial clinical series are comparable to the initial experience with other bifurcation support devices.

Long term follow-up of bifurcation aneurysms treated with braided stent assisted coiling and complex T- and Y- stent constructs.

BACKGROUND: Stent assisted coil embolization (SACE) of bifurcation aneurysms is challenging. Heterogeneous results have been achieved to date, but largely for laser cut stents. While braided stents offer multiple technical advantages, their long term efficacy has yet to be validated. OBJECTIVE: To report the first long term 18 month results for the durability of bifurcation aneurysms treated with braided stents. MATERIALS AND METHODS: Over a 4 year period, 59 consecutive patients with 60 bifurcation aneurysms underwent elective braided SACE across three Australian neurovascular centers. 17 of these aneurysms underwent T- or Y-shaped stent constructs. All patients had immediate, 6 month and 18 month clinical and radiological follow-up. Radiological assessment was made on modified Raymond-Roy occlusion scores while clinical assessment was based on the modified Rankin Scale. Subgroup analysis of 17 aneurysms treated with multi-stent constructs was conducted. RESULTS: 6 month follow-up data were available for 59 aneurysms and 18 month follow-up data for 58 aneurysms. Satisfactory aneurysm occlusion was achieved in 97% at inception and at 6 months, and 98% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Similar satisfactory results were achieved with the multi-stent construct cohort. Intraprocedural thromboembolic events were recorded in 5% and delayed events in 2%. Technical complications were found in 5%. All complication rate was 13%. CONCLUSION: Braided SACE was safe, efficacious, and durable at the long term 18 month follow-up, including for multi-stent constructs. Preliminary results indicate favorable clinical and radiological outcomes compared with laser cut stents.

Long-term follow-up of aneurysms treated electively with woven stent-assisted coiling.

BACKGROUND: Preliminary short-term results for stent-assisted coil embolization (SACE) using woven/braided stents have been promising. However, evidence supporting mid- to long-term efficacy and durability is lacking. OBJECTIVE: To report the long-term results for the durability of elective intracranial aneurysms treated with woven stents. MATERIALS AND METHODS: Between May 2012 and May 2015, 98 consecutive patients with 103 aneurysms underwent elective woven SACE across three Australian neurovascular centres. All patients had immediate, 6- and 18-month clinical and radiological follow-up. Radiological assessment was performed with modified Raymond-Roy occlusion scores based on angiography results, while clinical assessment was based on the modified Rankin Scale. RESULTS: Six-month follow-up was available in 100 aneurysms, and an 18-month follow-up in 97 aneurysms. Total occlusion rates of 82% were achieved at inception, 82% at 6 months, and 90% at 18 months. Satisfactory occlusion with small neck remnants was present in 17% at inception, 16% at 6 months, and 9% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Intraprocedural thromboembolic events were recorded in 3% and delayed events in 1% (all in patients taking clopidogrel). Aneurysm recurrence occurred in one patient (1%). Technical complications occurred in 5%. The total complication rate was 10%. CONCLUSIONS: Woven SACE is safe, efficacious, and durable at long-term 18-month follow-up, with very low recurrence and re-treatment rates. Preliminary results appear better than those for traditional laser-cut stents.

Successful endovascular thrombectomy 90h after stroke onset.

Endovascular thrombectomy (EVT) has extended the conventionally accepted time window of treatment, from 4.5h (ECASS III trial) for intravenous thrombolysis, to 7.3h for EVT (HERMES collaboration). More recent evidence suggests EVT times could be extended to 24h in carefully selected patients (DAWN trial). Some patients present after these time windows with large areas of ischemia but little established infarction on imaging. They represent a major dilemma with much to gain from EVT but at theoretically higher risk of a poor outcome. We present a case of near-complete left M1 occlusion in which EVT achieved reperfusion 90h 41min after stroke onset with excellent clinical outcome. Current guidelines on treatment windows for EVT according to HERMES collaboration do not reflect individual patient factors. In appropriate patients delayed EVT may give positive clinical outcomes.

Ultra-Early Angiographic Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis.

OBJECTIVE: After aneurysmal subarachnoid hemorrhage (aSAH), prognosis is affected heavily by the presence of delayed cerebral ischemia (DCI). There is growing recognition of ultra-early angiographic vasospasm (UEAV) occurring within 48 hours of aSAH; however, its relationship with DCI and ultimately prognosis remains unclear. METHODS: Various databases limited to the English language through September 2016 were searched systematically. Eligible studies were those comparing UEAV with control non-UEAV outcomes and follow-up. Two independent reviewers evaluated the quality of studies and abstracted the data, with discrepancies resolved by a third. We calculated odds ratios (ORs) and 95% confidence intervals for all outcomes by using random-effects meta-analyses and performed a heterogeneity analysis. RESULTS: Four comparative studies were selected for analysis. Pooled analysis demonstrated that UEAV compared with no-UEAV was associated with greater proportion of rupture aneurysms sized greater than 12 mm (38.3% vs. 24.3%, P < 0.00001). A significantly greater number of patients with UEAV had ruptured MCA aneurysms compared with patients without UEAV (29.7% vs. 19.9%, P = 0.005). Compared with no-UEAV, patients with UEAV were significantly associated with symptomatic cerebral vasospasm (OR 2.07, P = 0.05) and DCI/infarction (OR 2.52, P = 0.02). A significant association also was found between UEAV and an unfavorable outcome at follow-up (OR 1.64, P = 0.03) and greater mortality (OR 2.65, P < 0.00001). CONCLUSIONS: UEAV was significantly associated with symptomatic cerebral vasospasm, DCI/infarction, unfavorable outcome at follow-up, and greater mortality. Patients with intracerebral hematoma, intraventricular hemorrhage (Fisher Grade IV), larger ruptured aneurysms >12 mm, and an MCA location were more likely to have UEAV.

CT reconstruction and MRI fusion of 3D rotational angiography in the evaluation of pediatric cerebrovascular lesions.

PURPOSE: Complex neurovascular lesions in children require precise anatomic understanding for treatment planning. Although 3DRA is commonly employed for volumetric reformation in neurointerventional procedures, the ability to reconstruct this data into CT-like images (3DRA-CT) is not widely utilized. This study demonstrates the feasibility and usefulness of 3DRA-CT and subsequent MRI fusion for problem solving in pediatric neuroangiography. METHODS: This retrospective study includes 18 3DRA-CT studies in 16 children (age 9.6 ± 3.8 years, range 2-16 years) over 1 year. After biplane 2D-digital subtraction angiography (DSA), 5-second 3DRA was performed with selective vessel injection either with or without subtraction. Images were reconstructed into CT sections which were post-processed to generate multiplanar reformation (MPR) and maximum intensity projection (MIP) images. Fusion was performed with 3D T1 MRI images to precisely demonstrate neurovascular relationships. Quantitative radiation metrics were extracted and compared against those for the entire examination and for corresponding biplane 2D-DSA acquisitions. RESULTS: In all 18 cases, the 3DRA procedure and MRI fusion were technically successful and provided clinically useful information relevant to management. The unsubtracted and subtracted 3DRA acquisitions were measured to deliver 5.9 and 132.2%, respectively, of the mean radiation dose of corresponding biplane 2D-DSA acquisitions and contributed 1.2 and 12.5%, respectively, to the total procedure dose. CONCLUSION: Lower radiation doses, high spatial resolution, and multiplanar reformatting capability make 3DRA-CT a useful adjunct to evaluate neurovascular lesions in children. Fusing 3DRA-CT data with MRI is an additional capability that can further enhance diagnostic information.