Time-delayed contrast-enhanced MRI improves detection of brain metastases: a prospective validation of diagnostic yield.

The radiological detection of brain metastases (BMs) is essential for optimizing a patient's treatment. This statement is even more valid when stereotactic radiosurgery, a noninvasive image guided treatment that can target BM as small as 1-2 mm, is delivered as part of that care. The timing of image acquisition after contrast administration can influence the diagnostic sensitivity of contrast enhanced magnetic resonance imaging (MRI) for BM. Investigate the effect of time delayed acquisition after administration of intravenous Gadavist® (Gadobutrol 1 mmol/ml) on the detection of BM. This is a prospective IRB approved study of 50 patients with BM who underwent post-contrast MRI sequences after injection of 0.1 mmol/kg Gadavist® as part of clinical care (time-t0), followed by axial T1 sequences after a 10 min (time-t1) and 20 min delay (time-t2). MRI studies were blindly compared by three neuroradiologists. Single measure intraclass correlation coefficients were very high (0.914, 0.904 and 0.905 for time-t0, time-t1 and time-t2 respectively), corresponding to a reliable inter-observer correlation. The delayed MRI at time-t2 delayed sequences showed a significant and consistently higher diagnostic sensitivity for BM by every participating neuroradiologist and for the entire cohort (p = 0.016, 0.035 and 0.034 respectively). A disproportionately high representation of BM detected on the delayed studies was located within posterior circulation territories (compared to predictions based on tissue volume and blood-flow volumes). Considering the safe and potentially high yield nature of delayed MRI sequences, it should supplement the standard MRI sequences in all patients in need of precise delineation of their intracranial disease.

Detection of parathyroid adenomas using a monophasic dual-energy computed tomography acquisition: diagnostic performance and potential radiation dose reduction.

INTRODUCTION: The aims of the study were to compare the diagnostic performance of a combination of virtual non-contrast (VNC) images and arterial images obtained from a single-phase dual-energy CT (DECT) acquisition and standard non-contrast and arterial images from a biphasic protocol and to study the potential radiation dose reduction of the former approach. METHODS: All DECT examinations performed for evaluation of parathyroid adenomas during a 13-month period were retrospectively reviewed. An initial single-energy unenhanced acquisition was followed by a dual-energy arterial phase acquisition. "Virtual non-contrast images" were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated three different sets of images during three reading sessions: single arterial phase, single-phase DECT (virtual non-contrast and arterial phase), and standard biphasic protocol (true non-contrast and arterial phase). The accuracy of interpretation in lateralizing an adenoma to the side of the neck and localizing it to a quadrant in the neck was evaluated. RESULTS: Sixty patients (mean age, 65.5 years; age range, 38-87 years) were included in the study. The lateralization and localization accuracy, sensitivity, and positive predicted value (PPV) and negative predicted value (NPV) of the different image datasets were comparable. The combination of VNC and arterial images was more specific than arterial images alone to lateralize a parathyroid lesion (OR = 1.93, p = 0.043). The use of the single-phase protocol resulted in a calculated radiation exposure reduction of 52.8 %. CONCLUSIONS: Virtual non-contrast and arterial images from a single DECT acquisition showed similar diagnostic accuracy than a biphasic protocol, providing a significant dose reduction.

Combined microsurgical PICA-PICA bypass and endovascular parent artery occlusion for a ruptured dissecting vertebral artery aneurysm.

Dissecting vertebral artery (VA) aneurysms are difficult to obliterate when the parent artery cannot be safely occluded. In this video, we demonstrate a combined microsurgical and endovascular treatment technique for a ruptured, dissecting VA aneurysm incorporating the origin of the posterior inferior cerebellar artery (PICA). We first performed a PICA-PICA side-to-side bypass to preserve flow through the right PICA. An endovascular approach was then utilized to embolize the proximal portion of the aneurysm from the right VA and the distal portion of the aneurysm from the left VA. The video can be found here: http://youtu.be/dkkKsX2BiJI .

Endovascular Treatment of Venous Sinus Stenosis in Idiopathic Intracranial Hypertension: Complications, Neurological Outcomes, and Radiographic Results.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) may result in a chronic debilitating disease. Dural venous sinus stenosis with a physiologic venous pressure gradient has been identified as a potential etiology in a number of IIH patients. Intracranial venous stenting has emerged as a potential treatment alternative. METHODS: A systematic review was carried out to identify studies employing venous stenting for IIH. RESULTS: From 2002 to 2014, 17 studies comprising 185 patients who underwent 221 stenting procedures were reported. Mean prestent pressure gradient was 20.1 mmHg (95% CI 19.4-20.7 mmHg) with a mean poststent gradient of 4.4 mmHg (95% CI 3.5-5.2 mmHg). Complications occurred in 10 patients (5.4%; 95% CI 4.7-5.4%) but were major in only 3 (1.6%). At a mean clinical follow-up of 22 months, clinical improvement was noted in 130 of 166 patients with headaches (78.3%; 95% CI 75.8-80.8%), 84 of 89 patients with papilledema (94.4%; 95% CI 92.1-96.6%), and 64 of 74 patients with visual symptoms (86.5%; 95% CI 83.0-89.9%). In-stent stenosis was noted in six patients (3.4%; 95% CI 2.5-4.3%) and stent-adjacent stenosis occurred in 19 patients (11.4%; 95% CI 10.4-12.4), resulting in restenting in 10 patients. CONCLUSION: In IIH patients with venous sinus stenosis and a physiologic pressure gradient, venous stenting appears to be a safe and effective therapeutic option. Further studies are necessary to determine the long-term outcomes and the optimal management of medically refractory IIH.

Multimodal MR imaging model to predict tumor infiltration in patients with gliomas.

INTRODUCTION: Gliomas remain difficult to treat, in part, due to our inability to accurately delineate the margins of the tumor. The goal of our study was to evaluate if a combination of advanced MR imaging techniques and a multimodal imaging model could be used to predict tumor infiltration in patients with diffuse gliomas. METHODS: Institutional review board approval and written consent were obtained. This prospective pilot study enrolled patients undergoing stereotactic biopsy for a suspected de novo glioma. Stereotactic biopsy coordinates were coregistered with multiple standard and advanced neuroimaging sequences in 10 patients. Objective imaging values were assigned to the biopsy sites for each of the imaging sequences. A principal component analysis was performed to reduce the dimensionality of the imaging dataset without losing important information. A univariate analysis was performed to identify the statistically relevant principal components. Finally, a multivariate analysis was used to build the final model describing nuclear density. RESULTS: A univariate analysis identified three principal components as being linearly associated with the observed nuclear density (p values 0.021, 0.016, and 0.046, respectively). These three principal component composite scores are predominantly comprised of DTI (mean diffusivity or average diffusion coefficient and fractional anisotropy) and PWI data (rMTT, Ktrans). The p value of the model was <0.001. The correlation between the predicted and observed nuclear density was 0.75. CONCLUSION: A multi-input, single output imaging model may predict the extent of glioma invasion with significant correlation with histopathology.

Venous stenting with concurrent intracranial pressure monitoring for the treatment of pseudotumor cerebri.

Increasing evidence supports dural venous sinus stenosis as the patho-etiology of pseudotumor cerebri (PTC) in a subset of affected patients. In this video, we demonstrate our technique for 1) diagnostic venous manometry to identify a flow-limiting stenosis of the transverse sinus in a PTC patient; and 2) successful treatment of the patient with venous stenting across the structural and physiological stricture in the dural sinus. The pressure gradient decreased from 20 mmHg pre-stent to 3 mmHg post-stent. In order to further quantify the effect of our intervention, concurrent intracranial pressure monitoring was performed. The video can be found here: http://youtu.be/auxRg17F8yI .

Venous sinus stenting for reduction of intracranial pressure in IIH: a prospective pilot study.

OBJECTIVE Idiopathic intracranial hypertension (IIH) may cause blindness due to elevated intracranial pressure (ICP). Venous sinus stenosis has been identified in select patients, leading to stenting as a potential treatment, but its effects on global ICP have not been completely defined. The purpose of this pilot study was to assess the effects of venous sinus stenting on ICP in a small group of patients with IIH. METHODS Ten patients for whom medical therapy had failed were prospectively followed. Ophthalmological examinations were assessed, and patients with venous sinus stenosis on MR angiography proceeded to catheter angiography, venography with assessment of pressure gradient, and ICP monitoring. Patients with elevated ICP measurements and an elevated pressure gradient across the stenosis were treated with stent placement. RESULTS All patients had elevated venous pressure (mean 39.5 ± 14.9 mm Hg), an elevated gradient across the venous sinus stenosis (30.0 ± 13.2 mm Hg), and elevated ICP (42.2 ± 15.9 mm Hg). Following stent placement, all patients had resolution of the stenosis and gradient (1 ± 1 mm Hg). The ICP values showed an immediate decrease (to a mean of 17.0 ± 8.3 mm Hg), and further decreased overnight (to a mean of 8 ± 4.2 mm Hg). All patients had subjective and objective improvement, and all but one improved during follow-up (median 23.4 months; range 15.7-31.6 months). Two patients developed stent-adjacent stenosis; retreatment abolished the stenosis and gradient in both cases. Patients presenting with papilledema had resolution on follow-up funduscopic imaging and optical coherence tomography (OCT) and improvement on visual field testing. Patients presenting with optic atrophy had optic nerve thinning on follow-up OCT, but improved visual fields. CONCLUSIONS For selected patients with IIH and venous sinus stenosis with an elevated pressure gradient and elevated ICP, venous sinus stenting results in resolution of the venous pressure gradient, reduction in ICP, and functional, neurological, and ophthalmological improvement. As patients are at risk for stent-adjacent stenosis, further follow-up is necessary to determine long-term outcomes and gain an understanding of venous sinus stenosis as a primary or secondary pathological process behind elevated ICP.

Endovascular Treatment of a Fusiform Aneurysm at the M3-M4 Junction of the Middle Cerebral Artery Using the Pipeline Embolization Device.

BACKGROUND: Peripheral fusiform cerebral aneurysms remain difficult to treat. Current surgical approaches to the treatment of fusiform aneurysms include wrapping, clip occlusion or vessel reconstruction without parent vessel sacrifice, and aneurysm trapping with or without bypass, although these may carry high morbidity (36%). Classic endovascular approaches to the treatment of peripheral aneurysms include selective or parent artery occlusion, which imparts the risk of distal infarction. It may be possible to use a flow diversion device off label to treat the aneurysm and preserve flow to the distal territory. CASE DESCRIPTION: After a presyncopal event, a patient was found to have an unruptured fusiform aneurysm at the junction of the M3 and M4 segments of the right middle cerebral artery. After initiating dual antiplatelet therapy, the aneurysm was successfully treated with a Pipeline embolization device. Three months after treatment, the aneurysm has completely thrombosed, the parent artery remains widely patent, and the patient remains at her neurologic baseline. CONCLUSIONS: Flow diversion devices may provide the neurointerventional surgeon with an opportunity to treat fusiform peripheral aneurysms and preserve flow to the distal territory.

Preoperative Embolization of Cerebral Arteriovenous Malformations with Silk Suture and Particles: Technical Considerations and Outcomes.

OBJECTIVE: Embolization of cerebral arteriovenous malformations (AVMs) is commonly performed prior to surgical resection in order to reduce intraoperative bleeding and improve the safety of resection. Although most modern embolization procedures utilize permanent embolic agents, silk suture and polyvinyl alcohol (PVA) particles may offer unique advantages for preoperative devascularization. The aims of this retrospective cohort study are to describe the technical considerations and determine the outcomes for preoperative silk suture and PVA particle embolization (SPE) of AVMs. MATERIALS AND METHODS: We performed a retrospective review of our AVM embolization database. AVM patients who underwent preoperative SPE and subsequent surgical resection were included for analysis. Baseline patient demographics, AVM characteristics, embolization and operative records, and post-treatment outcomes were reviewed. RESULTS: A total of 11 patients who underwent 12 preoperative SPE procedures were included for analysis. Five AVMs were ruptured (45%), and the median nidus volume was 3.0 cm3 (range: 1.3-42.9 cm3). The Spetzler-Martin grade was I-II in seven patients (64%) and III-IV in four patients (36%). The degree of nidal obliteration was less than 25% in two procedures (17%), 25-50% in one procedure (8%), 50-75% in eight procedures (67%), and greater than 75% in one procedure (8%). The rates of post-embolization AVM hemorrhage and mortality were 8% and 0%, respectively. The postoperative angiographic obliteration rate was 100%, and the modified Rankin Scale score improved or stable in 91% of patients (median follow-up duration 2 months). CONCLUSION: Preoperative AVM SPE affords a reasonable risk to benefit profile for appropriately selected patients.

Clinical efficacy of 2-phase versus 4-phase computed tomography for localization in primary hyperparathyroidism.

BACKGROUND: Four-dimensional computed tomography is being used increasingly for localization of abnormal glands in primary hyperparathyroidism. We hypothesized that compared with traditional 4-phase imaging, 2-phase imaging would halve the radiation dose without compromising parathyroid localization and clinical outcomes. METHODS: A transition from 4-phase to 2-phase imaging was instituted between 2009 and 2010. A pre-post analysis was performed on patients undergoing operative treatment with a parathyroid protocol computed tomography, and relevant data were correlated with operative findings. Sensitivity, positive predictive value, technical success, and cure rates were calculated. The Fisher exact test or χ(2) test assessed the significance of 2-phase and 4-phase imaging and operative findings. RESULTS: Twenty-seven patients had traditional four-dimensional computed tomography and 35 had modified 2-phase computed tomography. Effective radiation doses were 6.8 mSy for 2-phase and 14 mSv for 4-phase. Four-phase computed tomography had a sensitivity and positive predictive value of 93% and 96%, respectively. Two-phase computed tomography had a comparable sensitivity and positive predictive value of 97% and 94%, respectively. Eight patients with discordant imaging had an average parathyroid weight of 240 g compared with 1,300 g for all patients. Technical surgical success (90% for 4-phase computed tomography versus 91% 2-phase computed tomography) and normocalcemia rates at 6 months (88% for both) did not differ between computed tomography protocols. Computed tomography correctly predicted multiglandular disease and localization for reoperations in 88% and 90% of cases, respectively, with no difference by computed tomography protocol. CONCLUSION: With regard to surgical outcomes and localization, 2-phase parathyroid computed tomography is equivalent to 4-phase for parathyroid localization, including small adenomas, reoperative cases, and multiglandular disease. Two-phase parathyroid computed tomography for operative planning should be considered to avoid unnecessary radiation exposure.

Prevalence of dural venous sinus stenosis and hypoplasia in a generalized population.

BACKGROUND AND PURPOSE: While recent literature has described the prevalence of transverse sinus stenosis in patients with idiopathic intracranial hypertension, tinnitus, and refractory headaches, it is unclear what the prevalence is in the general population. This study evaluates the prevalence of venous sinus stenosis and hypoplasia in the general patient population. MATERIALS AND METHODS: 355 of 600 consecutive patients who underwent CT angiography of the head met the inclusion criteria. The diameters of the dural venous sinuses were recorded. Each study was evaluated by a neuroradiologist for the presence of stenoses. Univariate and multivariate statistical analyses were performed by a statistician. RESULTS: The prevalence of unilateral transverse sinus stenosis or hypoplasia in a sample of patients representing the general population was 33%, the prevalence of bilateral transverse sinus stenosis was 5%, and the prevalence of unilateral stenosis with contralateral hypoplasia was 1%. A multivariate analysis identified arachnoid granulations as a predictor of stenosis (p<0.001). Gender trended toward significance (p=0.094). Race was not a significant predictor of stenosis (p=0.745). CONCLUSIONS: The prevalence of bilateral transverse sinus stenosis in the general population is not trivial. These data may be used as a reference for understanding the mechanistic role of stenoses in idiopathic intracranial hypertension, tinnitus, and refractory headaches.

Technology developments in endovascular treatment of intracranial aneurysms.

Advances in the management and endovascular treatment of intracranial aneurysms are progressing at a tremendous rate. Developments in novel imaging technology may improve diagnosis, risk stratification, treatment planning, intraprocedural assessment, and follow-up evaluation. Evolution of devices, including microwires, microcatheters, balloons, stents, and novel scaffolding devices, has greatly expanded the potential to treat difficult aneurysms. Although developments in technology have greatly improved the efficiency and efficacy of treatment of neurovascular disorders, novel devices do not always improve outcomes and may be associated with unique complications. As such, it is paramount to have an in-depth understanding of new devices and the implications of their introduction into clinical practice. This review provides an update on developments in endovascular treatment of intracranial aneurysms.

Endovascular treatment of ophthalmic artery aneurysms: ophthalmic artery patency following flow diversion versus coil embolization.

BACKGROUND AND PURPOSE: The Pipeline Embolization Device (PED) has been shown to effectively treat complex internal carotid artery aneurysms while maintaining patency of covered side branches. The purpose of this retrospective matched cohort study is to evaluate the effect of flow diversion on the patency of the ophthalmic artery when treating ophthalmic artery aneurysms. METHODS: A retrospective review of our prospectively collected institutional database identified 19 ophthalmic artery aneurysms treated with a PED. These were matched according to aneurysm diameter in a 1:2 fashion to ophthalmic artery aneurysms treated via coil embolization, although it is important to note that there was a statistically significance difference in the neck diameter between the two groups (p=0.045). Clinical and angiographic outcomes were recorded and analyzed. RESULTS: On follow-up angiography, decreased flow through the ophthalmic artery was observed in 26% of the PED cohort and 0% of the coil embolization cohort (p=0.003). No ophthalmologic complications were noted in either cohort. Complete occlusion at 12 months was more common following PED treatment than coil embolization (74% vs 47%; p=0.089), although lower than reported in previous trials. This may be due to inflow into the ophthalmic artery keeping the aneurysm patent. Retreatments were more common following coil embolization than PED (24% vs 11%), but this was not significant (p=0.304). Permanent morbidity rates were not significantly different between the PED (11%) and coil embolization (3%) cohorts (p=0.255). CONCLUSIONS: Our results suggest that ophthalmic artery aneurysms may be adequately and safely treated with either the PED or coil embolization. However, treatment with the PED carries a higher risk of impeding flow to the ophthalmic artery, although this did not result in clinical sequelae in the current study.

A method for complete angiographic obliteration of a brain arteriovenous malformation in a single session through a single pedicle.

Historically, the endovascular treatment of arteriovenous malformations (AVM) has largely been relegated to an adjunctive role to open surgical and radiosurgical methods. In this article, we describe a novel endovascular approach to the treatment of brain AVM using Onyx (ev3 Endovascular, Plymouth, MN, USA), which may allow for a complete angiographic obliteration in a single treatment session. Twelve patients underwent Onyx embolization of an AVM using a novel "reverse plug and push" technique in which a plug is formed around the treatment catheter prior to injecting Onyx into the AVM. The plug mitigates the risk of backflow and catheter entrapment, thereby allowing the user to inject higher volumes of Onyx at higher injection rates. Patient demographics, AVM characteristics, and treatment details were reviewed. Using the "reverse plug then push" technique, an average of 8.8 mL of Onyx was injected into the AVM in a single session. In every case, the microcatheter was removed easily with minimal traction pressure. Complete angiographic obliteration was achieved in 83% of patients after a single treatment. Morbidity and mortality were 8% each. The "reverse plug then push" technique allows for a more rapid injection of Onyx due to the formation of a well-controlled plug prior to treatment, mitigating the risk of catheter entrapment by Onyx reflux. With further refinement, this technique may present a viable curative option for treatment of select brain AVM.

Optimal Symmetric Multimodal Templates and Concatenated Random Forests for Supervised Brain Tumor Segmentation (Simplified) with ANTsR.

Segmenting and quantifying gliomas from MRI is an important task for diagnosis, planning intervention, and for tracking tumor changes over time. However, this task is complicated by the lack of prior knowledge concerning tumor location, spatial extent, shape, possible displacement of normal tissue, and intensity signature. To accommodate such complications, we introduce a framework for supervised segmentation based on multiple modality intensity, geometry, and asymmetry feature sets. These features drive a supervised whole-brain and tumor segmentation approach based on random forest-derived probabilities. The asymmetry-related features (based on optimal symmetric multimodal templates) demonstrate excellent discriminative properties within this framework. We also gain performance by generating probability maps from random forest models and using these maps for a refining Markov random field regularized probabilistic segmentation. This strategy allows us to interface the supervised learning capabilities of the random forest model with regularized probabilistic segmentation using the recently developed ANTsR package--a comprehensive statistical and visualization interface between the popular Advanced Normalization Tools (ANTs) and the R statistical project. The reported algorithmic framework was the top-performing entry in the MICCAI 2013 Multimodal Brain Tumor Segmentation challenge. The challenge data were widely varying consisting of both high-grade and low-grade glioma tumor four-modality MRI from five different institutions. Average Dice overlap measures for the final algorithmic assessment were 0.87, 0.78, and 0.74 for "complete", "core", and "enhanced" tumor components, respectively.

Embolization of cerebral arteriovenous malformations with silk suture particles prior to stereotactic radiosurgery.

We aimed to determine the long term durability of silk suture and polyvinyl alcohol (PVA) particle embolization (SPE) of arteriovenous malformations (AVM), and to evaluate the outcomes following multimodality management of AVM with combined SPE and stereotactic radiosurgery (SRS). A general supposition among neurointerventionalists is that embolization of cerebral AVM with silk sutures and PVA particles does not yield a durable occlusion. We performed a retrospective review of all AVM patients treated at our institution with combined SPE and SRS. After extracting the baseline, embolization and SRS data for each patient, the durability of SPE was determined by evaluating the postembolization recanalization between the last procedural angiogram and the most recent neuroimaging. Four AVM patients who underwent a total of nine SPE procedures through 21 arterial pedicles were included for the analyses. The nidus volumes were 5.8-75 cm(3) and the Spetzler-Martin grades were II and V in one patient and III in two patients. The median degree of devascularization per procedure was <25%. There were no procedural complications, with all patients maintaining functional independence after embolization (modified Rankin scale score 0-2). After a median follow-up duration of 27 months (range: 23-36), there were no patients with recanalization. SRS (marginal dose 13-18 Gy) resulted in 40 to >95% volume reduction. Following SRS, one patient remained asymptomatic, two patients improved, and one patient deteriorated due to a latency period AVM hemorrhage. In conclusion, SPE can safely provide durable AVM devascularization, therefore, appropriately selected nidi can be effectively treated with combined SPE and SRS.

Noninvasive evaluation of the regional variations of GABA using magnetic resonance spectroscopy at 3 Tesla.

PURPOSE: Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating motor diseases, neurological disorders, or psychiatric dysfunction. MATERIALS AND METHODS: In this prospective study, eight healthy volunteers underwent spectroscopic evaluation of the frontal lobe, occipital lobe, lateral temporal lobe, basal ganglia, and both hippocampi using a spin echo variant of a J-difference editing method. Knowledge of the relative peak intensities of the macromolecule peaks at 3ppm and 0.9ppm was used to correct the contribution of co-edited macromolecules to the GABA peak at 3ppm. The GABA values were internally referenced to NAA. Linear regression was used to normalize the effect of regional tissue-fraction variation on the GABA/NAA values. A one-way ANOVA was performed with Tukey's multiple comparison test to compare the normalized GABA/NAA values in each pair of locations. RESULTS: After accounting for the macromolecule contribution to the GABA signal and correction for tissue fraction variation, the normalized GABA/NAA ratios differ significantly between the six brain locations (p<0.001). Pairwise comparisons of the corrected normalized GABA/NAA ratios show statistically significant variation between the frontal lobe and the basal ganglia, frontal and lateral temporal lobes, and frontal lobe and right hippocampus. Variations in the normalized GABA/NAA ratios trend toward significance between the frontal lobe and left hippocampus, occipital lobe and the frontal lobe, occipital lobe and basal ganglia, and occipital lobe and right hippocampus. CONCLUSION: Our study suggests that GABA concentration is inhomogeneous throughout the parenchyma. Studies evaluating the role of GABA must carefully consider voxel placement when incorporating spectroscopy.

Endovascular treatment of unruptured wide-necked intracranial aneurysms: comparison of dual microcatheter technique and stent-assisted coil embolization.

BACKGROUND: Endovascular treatment of wide-necked aneurysms is challenging. Stent-assisted coiling (SAC) is associated with increased complications and requires dual antiplatelet therapy. OBJECTIVE: To compare treatment of unruptured, wide-necked aneurysms with a dual-microcatheter technique (DMT) versus SAC. METHODS: Between 2006 and 2011, 100 patients with unruptured wide-necked intracranial aneurysms were treated with DMT and 160 with SAC. Over time there was a significant decrease in the use of SAC and a corresponding increase in DMT. The investigators matched 60 patients treated with DMT blinded to outcome in a 1:2 fashion based on maximal aneurysm dome diameter with 120 patients treated with SAC. Outcomes were determined with conditional (matched) multivariate analysis. RESULTS: There were no significant differences in patient or aneurysm characteristics between cohorts, including aneurysm diameter, neck width, or volume. Overall packing density and coil volume achieved was not significantly different between cohorts. There were higher rates of overall complications in those receiving SAC (19.2%) compared with DMT (5.0%; p=0.012), but no significant difference in major complications (8.3% vs 1.7%, respectively; p=0.103). At a mean follow-up of 27.0 ± 18.9 months, rates of retreatment did not differ between DMT (15.1%) and SAC (17.7%). Delayed in-stent stenosis occurred in five patients and in-stent thrombosis in four patients treated with SAC. There was no difference in favorable functional outcome (modified Rankin score 0-2) between those treated with DMT (90.6%) compared with SAC (91.2%). CONCLUSIONS: DMT and SAC are effective endovascular approaches for unruptured, wide-necked aneurysms; however, DMT may result in less morbidity. Further long-term studies are necessary to determine the optimal indications for these treatment options.

Stenting of symptomatic intracranial stenosis using balloon mounted coronary stents: a single center experience.

OBJECTIVE: Intracranial atherosclerotic disease is the cause of up to 10% of ischemic strokes and transient ischemic attacks. Intracranial stenting with off-label balloon mounted coronary stents (BMCS) may be a viable alternative for patients with symptomatic intracranial stenosis who fail best medical therapy. DESIGN: Between December 2005 and June 2012, 42 symptomatic intracranial stenoses were treated with a BMCS after failing medical management. Procedural records, clinical outcomes, and imaging follow-up were reviewed. Outcome measurements included technical success rate, morbidity and mortality, long term stent patency, and clinical outcomes, as measured by the modified Rankin Scale. RESULTS: The technical success rate was 98% (41 of 42 lesions). Morbidity within the first 30 days was 7.1% (three of 42 lesions). Overall morbidity, including both periprocedural and long term evaluation, was 9.5% (four of 42 lesions). There were no deaths. Follow-up imaging was available for 30 stents (71%) with an average follow-up time of 35.1 months. Restenosis (>50%) and retreatment were observed in 20% and 10% of cases, respectively. Clinical evaluation by a neurologist ≥ 30 days postprocedure was available in 40 of 42 cases (95%) with an average of 32.1 months. At presentation, 55% of patients had a modified Rankin Scale (mRS) score of ≤ 2. At follow-up, 74% of patients were found to have an mRS score of ≤ 2. CONCLUSIONS: This study suggests that BMCS may benefit patients with symptomatic intracranial stenosis who experience stroke or transient ischemic attack in spite of best medical therapy.

The Multimodal Brain Tumor Image Segmentation Benchmark (BRATS).

In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low- and high-grade glioma patients-manually annotated by up to four raters-and to 65 comparable scans generated using tumor image simulation software. Quantitative evaluations revealed considerable disagreement between the human raters in segmenting various tumor sub-regions (Dice scores in the range 74%-85%), illustrating the difficulty of this task. We found that different algorithms worked best for different sub-regions (reaching performance comparable to human inter-rater variability), but that no single algorithm ranked in the top for all sub-regions simultaneously. Fusing several good algorithms using a hierarchical majority vote yielded segmentations that consistently ranked above all individual algorithms, indicating remaining opportunities for further methodological improvements. The BRATS image data and manual annotations continue to be publicly available through an online evaluation system as an ongoing benchmarking resource.