Background and Purpose To evaluate the potential clinical value of arterial spin labeled (ASL) perfusion MRI in acute ischemic stroke (AIS) through comparison with dynamic susceptibility contrast (DSC) enhanced perfusion MRI. Methods Pseudo-continuous ASL with 3D background suppressed GRASE (Gradient and Spin Echo) readout was applied with DSC perfusion MRI on 26 AIS patients. ASL CBF and multi-parametric DSC perfusion maps were rated for image quality and lesion severity/conspicuity. Mean ASL CBF and DSC perfusion values were obtained in main vascular territories. Kendall’s coefficient of concordance was calculated to evaluate the reliability of ratings. Spearman correlation coefficients were calculated to compare ratings and quantitative perfusion values between ASL and DSC perfusion maps. Results ASL CBF and DSC perfusion maps provided largely consistent results in delineating hypoperfused brain regions in AIS. Hyperemic lesions, which also appeared frequently in the AIS cases studied, were more conspicuous on ASL CBF than on DSC CBF, Mean Transit Time (MTT) and Time to the maximum of the tissue residual function (Tmax) maps. Conclusions As a rapid, noninvasive and quantitative technique, ASL has clinical utility in detecting blood flow abnormalities in AIS patients.

Our study shows preliminary data from three centers on recanalization of tandem occlusions in patients presenting with AIS. There was a preference to revascularize the proximal occlusion using a stent followed by distal recanalization with mechanical thrombectomy, intra-arterial thrombolysis or a combination of these. This approach has low periprocedural complications and can achieve an excellent angiographic and clinical outcome.

Background and purpose Developments in flat-panel angiographic c-arm systems have enabled visualization of both the neurovascular stents and host arteries in great detail, providing complementary spatial information in addition to conventional DSA. However, the visibility of these structures may be impeded by artifacts generated by adjacent radio-attenuating objects. We report on the use of a metal artifact reduction (MAR) algorithm for high resolution contrast-enhanced CBCT (VasoCT) for follow-up imaging of stent-assisted coil embolization. Materials and methods VasoCT data was acquired in 25 patients that underwent stent-assisted coiling. Reconstructions were generated with and without MAR and were reviewed by three experienced neuroradiologists using a 3-point scale. Results With MAR, the observers agreed that the visibility had improved by at least one point on the scoring scale in more than 40% of the cases (κ = 0.6) and that the streak artifact was not obscuring surrounding structures in 64% of all cases (κ = 0.6). MAR improved the image quality which allowed for visibility sufficient for evaluation in 65% of the cases, and was preferred over no MAR in 92% (κ = 0.9). Significantly higher scores were given with MAR (p < 0.0001). Conclusion Although MAR is not capable of fully removing artifacts caused by implants with high x-ray absorption, we have shown that the image quality of VasoCT data is improved drastically. The impact of the artifacts on the visibility varied between cases, and yet the overall visibility of the contrast-enhanced CBCT with MAR improved in the majority of the cases.

Background and Purpose: Stent-assisted coil embolization using the new generation Neuroform Atlas Stent System has shown promising safety and efficacy. The primary study results of the anterior circulation aneurysm cohort of the treatment of wide-neck, saccular, intracranial, aneurysms with the Neuroform Atlas Stent System (ATLAS trial [Safety and Effectiveness of the Treatment of Wide Neck, Saccular Intracranial Aneurysms With the Neuroform Atlas Stent System]) are presented. Methods: ATLAS IDE trial (Investigational Device Exemption) is a prospective, multicenter, single-arm, open-label study of wide-neck (neck ≥4 mm or dome-to-neck ratio <2) intracranial aneurysms in the anterior circulation treated with the Neuroform Atlas Stent and approved coils. The primary efficacy end point was complete aneurysm occlusion (Raymond-Roy class 1) on 12-month angiography, in the absence of retreatment or parent artery stenosis (>50%) at the target location. The primary safety end point was any major stroke or ipsilateral stroke or neurological death within 12 months. Adjudication of the primary end points was performed by an independent Imaging Core Laboratory and the Clinical Events Committee. Results: A total of 182 patients with wide-neck anterior circulation aneurysms at 25 US centers were enrolled. The mean age was 60.3±11.4 years, 73.1% (133/182) women, and 80.8% (147/182) white. Mean aneurysm size was 6.1±2.2 mm, mean neck width was 4.1±1.2 mm, and mean dome-to-neck ratio was 1.2±0.3. The most frequent aneurysm locations were the anterior communicating artery (64/182, 35.2%), internal carotid artery ophthalmic artery segment (29/182, 15.9%), and middle cerebral artery bifurcation (27/182, 14.8%). Stents were placed in the anticipated anatomic location in all patients. The study met both primary safety and efficacy end points. The composite primary efficacy end point of complete aneurysm occlusion (Raymond-Roy 1) without parent artery stenosis or aneurysm retreatment was achieved in 84.7% (95% CI, 78.6%–90.9%) of patients. Overall, 4.4% (8/182, 95% CI, 1.9%–8.5%) of patients experienced a primary safety end point of major ipsilateral stroke or neurological death. Conclusions: In the ATLAS IDE anterior circulation aneurysm cohort premarket approval study, the Neuroform Atlas stent with adjunctive coiling met the primary end points and demonstrated high rates of long-term complete aneurysm occlusion at 12 months, with 100% technical success and <5% morbidity. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02340585.

Our preliminary results show that flow diversion technology is an effective and safe therapy for aneurysms located on small cerebral arteries. Larger studies with long-term follow-up are needed to validate our promising results.

Our preliminary experience with the use of PED for the treatment of intradural VA dissecting aneurysms shows promising short-term results, making this technique a feasible and safe treatment option in patients suitable for this approach. However, long-term and larger cohort studies are needed to validate these results.

Our results suggest that SACE of aneurysms with small parent vessels is feasible in selected cases and shows good long-term patency rates of parent arteries.

Our preliminary results show that flow diversion technology is an effective and safe therapy for complex, hard-to-treat aneurysms in perforating arteries. Larger studies with long-term follow-up are needed to validate our promising results.