Differential Subsampling with Cartesian Ordering-MRA for Classifying Residual Treated Aneurysms.

BACKGROUND AND PURPOSE: Differential Subsampling with Cartesian Ordering (DISCO), an ultrafast high-spatial-resolution head MRA, has been introduced. We aimed to determine the diagnostic performance of DISCO-MRA in grading residual aneurysm in comparison with TOF-MRA in patients with treated intracranial aneurysms. MATERIALS AND METHODS: Patients with endovascular treatment and having undergone DISCO-MRA, TOF-MRA, and DSA were included for review. The voxel size and acquisition time were 0.75 × 0.75 × 1 mm3/6 seconds for DISCO-MRA and 0.6 × 0.6 × 1 mm3/6 minutes for TOF-MRA. Residual aneurysms were determined using the Modified Raymond-Roy Classification on TOF-MRA and DISCO-MRA by 2 neuroradiologists independently and were compared against DSA as the reference standard. Statistical analysis was performed using the κ statistic and the χ2 test. RESULTS: Sixty-eight treated intracranial aneurysms were included. The intermodality agreement was κ = 0.82 (95% CI, 0.67-0.97) between DISCO and DSA and 0.44 (95% CI, 0.28-0.61) between TOF and DSA. Modified Raymond-Roy Classification scores matched DSA scores in 60/68 cases (88%; χ2 = 144.4, P < .001 for DISCO and 46/68 cases (68%; χ2 = 65.0, P < .001) for TOF. The diagnostic accuracy for the detection of aneurysm remnants was higher for DISCO (0.96; 95% CI, 0.88-0.99) than for TOF (0.79; 95% CI, 0.68-0.88). CONCLUSIONS: In patients with endovascularly treated intracranial aneurysms, DISCO-MRA provides superior diagnostic performance in comparison with TOF-MRA in delineating residual aneurysms in a fraction of the time.

Transradial Approach for Neuroendovascular Procedures: A Single-Center Review of Safety and Feasibility.

BACKGROUND AND PURPOSE: In recent years, the transradial approach has become more widely adopted for neuroendovascular procedures. The purpose of this study was to evaluate the safety and feasibility of a transradial approach and distal transradial access for neuroendovascular procedures in a single center. MATERIALS AND METHODS: Retrospective analysis was performed for all patients who underwent transradial approach or distal transradial access neuroendovascular procedures from January 2016 to August 2019 at a single center. Exclusion criteria included a Barbeau D waveform, a radial artery of <2 mm on sonographic evaluation, and known radial artery occlusion. Procedures were evaluated for technical success (defined as successful radial artery access and completion of the intended procedure without crossover to an auxiliary access site), complications, and adverse events during follow-up at 30 days. RESULTS: The transradial approach or distal transradial access was attempted in 279 consecutive patients (58.1% women; median age, 57.7 years) who underwent 328 standard or distal transradial approach procedures. Two-hundred seventy-nine transradial approach and 49 distal transradial approach procedures were performed (cerebral angiography [n = 213], intracranial intervention [n = 64], head and neck intervention [n = 30], and stroke intervention [n = 21]). Technical success was 92.1%. Immediate adverse events (2.1%) included radial access site hematoma (n = 5), radial artery occlusion (n = 1), and acute severe radial artery spasm (n = 1). Thirty-day adverse events (0.3%) included a radial artery pseudoaneurysm (n = 1). Twenty-six cases (7.9%) required crossover to transfemoral access. CONCLUSIONS: The transradial approach for neuroendovascular procedures is safe and feasible across a wide range of neuroendovascular interventions.

A Radiologic Grading System for Assessing the Radiographic Outcome of Treatment in Lymphatic and Lymphatic-Venous Malformations of the Head and Neck.

BACKGROUND AND PURPOSE: Two-thirds of lymphatic malformations in children are found in the head and neck. Although conventionally managed through surgical resection, percutaneous sclerotherapy has gained popularity. No reproducible grading system has been designed to compare sclerotherapy outcomes on the basis of radiologic findings. We propose an MR imaging-based grading scale to assess the response to sclerotherapy and present an evaluation of its interrater reliability. MATERIALS AND METHODS: A grading system was developed to stratify treatment outcomes on the basis of interval changes observed on MR imaging. By means of this system, 56 consecutive cases from our institution with formally diagnosed head and neck lymphatic malformations treated by sclerotherapy were retrospectively graded. Each patient underwent pre- and posttreatment MR imaging. Each study was evaluated by 3 experienced neuroradiologists. Interrater reliability was assessed using the Krippendorff α statistic, intraclass coefficient, and 2-way Spearman ρ correlation. RESULTS: The overall Krippendorff α statistic was 0.93 (95% CI, 0.89-0.95), denoting excellent agreement among raters. Intraclass coefficients with respect to consistency and absolute agreements were both 0.97 (95% CI, 0.96-0.98), illustrating low variability. Every combination of individual rater pairs demonstrated statistically significant (P < .01) linear Spearman ρ correlations, with values ranging from 0.90 to 0.95. CONCLUSIONS: The proposed radiographic grading scale demonstrates excellent interrater reliability. Adoption of this new scale can standardize reported outcomes following sclerotherapy for head and neck lymphatic malformation and may aid in the investigation of future questions regarding optimal management of these lesions.

Early Postmarket Results with EmboTrap II Stent Retriever for Mechanical Thrombectomy: A Multicenter Experience.

BACKGROUND AND PURPOSE: EmboTrap II is a novel stent retriever with a dual-layer design and distal mesh designed for acute ischemic stroke emergent large-vessel occlusions. We present the first postmarket prospective multicenter experience with the EmboTrap II stent retriever. MATERIALS AND METHODS: A prospective registry of patients treated with EmboTrap II at 7 centers following FDA approval was maintained with baseline patient characteristics, treatment details, and clinical/radiographic follow-up. RESULTS: Seventy patients were treated with EmboTrap II (mean age, 69.9 years; 48.6% women). Intravenous thrombolysis was given in 34.3%, and emergent large-vessel occlusions were located in the ICA (n = 18), M1 (n = 38), M2 or M3 (n = 13), and basilar artery (n = 1). The 5 × 33 mm device was used in 88% of cases. TICI ≥ 2b recanalization was achieved in 95.7% (82.3% in EmboTrap II-only cases), and first-pass efficacy was achieved in 35.7%. The NIHSS score improved from a preoperative average of 16.3 to 12.1 postprocedure and to 10.5 at discharge. An average of 2.5 [SD, 1.8] passes was recorded per treatment, including non-EmboTrap attempts. Definitive treatment was performed with an alternative device (aspiration or stent retriever) in 9 cases (12.9%). Some hemorrhagic conversion was noted in 22.9% of cases, of which 4.3% were symptomatic. There were no device-related complications. CONCLUSIONS: Initial postmarket results with the EmboTrap II stent retriever are favorable and comparable with those of other commercially available stent retrievers. Compared with EmboTrap II, the first-generation EmboTrap may have a higher first-pass efficacy; however, data are limited by retrospective case analysis, incomplete clinical follow-up, and small sample size, necessitating future trials.

Angiographic and Clinical Features of Noninvoluting Congenital Hemangiomas.

While infantile hemangiomas are very common, congenital hemangiomas are rare and less understood. Congenital hemangiomas are present at birth. They fall into 2 major categories: rapidly involuting congenital hemangioma and noninvoluting congenital hemangioma. Noninvoluting congenital hemangioma is the rarer of the 2 entities. If not recognized and treated appropriately, noninvoluting congenital hemangioma can lead to considerable morbidity. There is a paucity of literature regarding noninvoluting congenital hemangiomas. In this article, we will outline our experience with this condition, focusing on clinical and angiographic features. There is a distinct angiographic appearance of noninvoluting congenital hemangiomas involving an arterial-capillary web, a dense tumor blush with identifiable feeding arteries, no arteriovenous shunting, and variably present draining veins. Our experience with endovascular embolization and direct percutaneous treatment is the largest for this entity to date. Endovascular embolization and/or direct percutaneous sclerotherapy of this lesion may obviate subsequent surgical resection.

Defining Ischemic Core in Acute Ischemic Stroke Using CT Perfusion: A Multiparametric Bayesian-Based Model.

BACKGROUND AND PURPOSE: The Bayesian probabilistic method has shown promising results to offset noise-related variability in perfusion analysis. Using CTP, we aimed to find optimal Bayesian-estimated thresholds based on multiparametric voxel-level models to estimate the ischemic core in patients with acute ischemic stroke. MATERIALS AND METHODS: Patients with anterior circulation acute ischemic stroke who had baseline CTP and achieved successful recanalization were included. In a subset of patients, multiparametric voxel-based models were constructed between Bayesian-processed CTP maps and follow-up MRIs to identify pretreatment CTP parameters that were predictive of infarction using robust logistic regression. Subsequently CTP-estimated ischemic core volumes from our Bayesian model were compared against routine clinical practice oscillation singular value decomposition-relative cerebral blood flow <30%, and the volumetric accuracy was assessed against final infarct volume. RESULTS: In the constructed multivariate voxel-based model, 4 variables were identified as independent predictors of infarction: TTP, relative CBF, differential arterial tissue delay, and differential mean transit time. At an optimal cutoff point of 0.109, this model identified infarcted voxels with nearly 80% accuracy. The limits of agreement between CTP-estimated ischemic core and final infarct volume ranged from -25 to 27 mL for the Bayesian model, compared with -61 to 52 mL for oscillation singular value decomposition-relative CBF. CONCLUSIONS: We established thresholds for the Bayesian model to estimate the ischemic core. The described multiparametric Bayesian-based model improved consistency in CTP estimation of the ischemic core compared with the methodology used in current clinical routine.

MR Perfusion to Determine the Status of Collaterals in Patients with Acute Ischemic Stroke: A Look Beyond Time Maps.

BACKGROUND AND PURPOSE: Patients with acute stroke with robust collateral flow have better clinical outcomes and may benefit from endovascular treatment throughout an extended time window. Using a multiparametric approach, we aimed to identify MR perfusion parameters that can represent the extent of collaterals, approximating DSA. MATERIALS AND METHODS: Patients with anterior circulation proximal arterial occlusion who had baseline MR perfusion and DSA were evaluated. The volume of arterial tissue delay (ATD) at thresholds of 2-6 seconds (ATD2-6 seconds) and >6 seconds (ATD>6 seconds) in addition to corresponding values of normalized CBV and CBF was calculated using VOI analysis. The association of MR perfusion parameters and the status of collaterals on DSA were assessed by multivariate analyses. Receiver operating characteristic analysis was performed. RESULTS: Of 108 patients reviewed, 39 met our inclusion criteria. On DSA, 22/39 (56%) patients had good collaterals. Patients with good collaterals had significantly smaller baseline and final infarct volumes, smaller volumes of severe hypoperfusion (ATD>6 seconds), larger volumes of moderate hypoperfusion (ATD2-6 seconds), and higher relative CBF and relative CBV values than patients with insufficient collaterals. Combining the 2 parameters into a Perfusion Collateral Index (volume of ATD2-6 seconds × relative CBV2-6 seconds) yielded the highest accuracy for predicting collateral status: At a threshold of 61.7, this index identified 15/17 (88%) patients with insufficient collaterals and 22/22 (100%) patients with good collaterals, for an overall accuracy of 94.1%. CONCLUSIONS: The Perfusion Collateral Index can predict the baseline collateral status with 94% diagnostic accuracy compared with DSA.

The Use and Utility of Aspiration Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: Thrombectomy trials are often specifically interpreted as evidence for the effectiveness of stent retrievers. The effectiveness of other thrombectomy techniques such as aspiration thrombectomy should be validated through further investigation and review. PURPOSE: To evaluate published treatment times and clinical outcomes in patients treated with aspiration thrombectomy or ADAPT (A Direct Aspiration, First Pass Technique) for acute ischemic stroke. DATA SOURCES: A systematic literature review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Scopus, and the Cochrane trial register were searched on November 8, 2016. STUDY SELECTION: Twenty studies (n = 1523 patients) were included in this review and meta-analysis. One of these studies was prospective, and the rest were retrospective. DATA ANALYSIS: Meta-analysis was performed by using a random effects model. Data and publication bias were visualized with forest plots and funnel plots. DATA SYNTHESIS: Five studies investigated aspiration thrombectomy only, and 16 studies investigated ADAPT. Of the 16 studies on ADAPT, the rate of successful recanalization (TICI 2b/3) was 89.3% (95% CI, 85.4%-92.3%). The proportion of patients with good clinical outcome (90-day mRS ≤2) was 52.7% (95% CI, 48.0%-57.4%). LIMITATIONS: Studies on ADAPT were retrospective, and there was heterogeneity between studies for successful recanalization (P < .001) and good clinical outcome (P < .001). There was evidence of publication bias for recanalization rates (P = .01), but not for clinical outcomes (P = .42). CONCLUSIONS: ADAPT and aspiration thrombectomy are effective approaches to thrombectomy, with high recanalization rates and excellent clinical outcomes reported in the literature. Aspiration thrombectomy is a promising neurointervention, but large prospective randomized studies are needed to validate its utility.