Christen D. Barras

Density and Shape as CT Predictors of Intracerebral Hemorrhage Growth

Background and Purpose— Intracerebral hemorrhage (ICH) growth predicts mortality and functional outcome. We hypothesized that irregular hematoma shape and density heterogeneity, reflecting active, multifocal bleeding or a variable bleeding time course, would predict ICH growth. Methods— Three raters examined baseline sub-3-hour CT brain scans of 90 patients in the placebo arm of a Phase IIb trial of recombinant activated Factor VII in ICH. Each rater, blinded to growth data, independently applied novel 5-point categorical scales of density and shape to randomly presented baseline CT images of ICH. Density and shape were defined as either homogeneous/regular (Category 1 to 2) or heterogeneous/irregular (Category 3 to 5). Within- and between-rater reliability was determined for these scales. Growth was assessed as a continuous variable and using 3 binary definitions: (1) any ICH growth; (2) ≥33% or ≥12.5 mL ICH growth; and (3) radial growth >1 mm between baseline and 24-hour CT scan. Patients were divided into tertiles of baseline ICH volume: “small” (0 to 10 mL), “medium” (10 to 25 mL), and “large” (25 to 106 mL). Results— Inter- and intrarater agreements for the novel scales exceeded 85% (±1 category). Median growth was significantly higher in the large-volume group compared with the small group (P<0.001) and in heterogeneous compared with homogeneous ICH (P=0.008). Median growth trended higher in irregular ICHs compared with regular ICHs (P=0.084). Small ICHs were more regularly shaped (43%) than medium (17%) and large (3%) ICHs (P<0.001). Small ICHs were more homogeneous (73%) compared with medium (37%) and large (17%) ICHs (P<0.001). Adjusting for baseline ICH volume and time to scan, density heterogeneity, but not shape irregularity, independently predicted ICH growth (P=0.046) on a continuous growth scale. Conclusions— Large ICHs were significantly more irregular in shape, heterogeneous in density, and had greater growth. Density heterogeneity independently predicted ICH growth using some definitions.

Quantitative CT Densitometry for Predicting Intracerebral Hemorrhage Growth

BACKGROUND AND PURPOSE: Intracerebral hemorrhage growth independently predicts disability and death. We hypothesized that noncontrast quantitative CT densitometry reflects active bleeding and improves predictive models of growth. MATERIALS AND METHODS: We analyzed 81 of the 96 available baseline CT scans obtained <3 hours post-ICH from the placebo arm of the phase IIb trial of recombinant factor VIIa. Fifteen scans could not be analyzed for technical reasons, but baseline characteristics were not statistically significantly different. Hounsfield unit histograms for each ICH were generated. Analyzed qCTD parameters included the following: mean, SD, coefficient of variation, skewness (distribution asymmetry), and kurtosis (“peakedness” versus “flatness”). These densitometry parameters were examined in statistical models accounting for baseline volume and time-to-scan. RESULTS: The coefficient of variation of the ICH attenuation was the most significant individual predictor of hematoma growth (adjusted R2 = 0.107, P = .002), superior to BV (adjusted R2 = 0.08, P = .006) or TTS (adjusted R2 = 0.03, P = .05). The most significant combined model incorporated coefficient of variation, BV, and TTS (adjusted R2 = 0.202, P = .009 for coefficient of variation) compared with BV and TTS alone (adjusted R2 = 0.115, P < .05). qCTD increased the number of growth predictions within ±1 mL of actual 24-hour growth by up to 47%. CONCLUSIONS: Heterogeneous ICH attenuation on hyperacute (<3 hours) CT imaging is predictive of subsequent hematoma expansion and may reflect an active bleeding process. Further studies are required to determine whether qCTD can be incorporated into standard imaging protocols for predicting ICH growth.

Brain imaging in transient ischemic attack – redefining TIA

Transient ischemic attack (TIA) has recently been redefined to incorporate the latest clinical and neuroimaging information that has shed new light on TIA pathophysiology. Patients suffering from TIA are at a substantial risk of subsequent stroke, but quantifying this risk is difficult as TIA patients are a heterogeneous population and there are multiple TIA mimics. Clinical scores for prediction of stroke risk are principally based on patient history and potentially understate actual risk. Magnetic resonance imaging (MRI), in particular diffusion-weighted imaging (DWI) performed in the first days following TIA, reveals relevant focal ischemic abnormalities in 21-68% of patients. These lesions predict stroke recurrence, functional dependence and subsequent vascular events. Adding imaging information to clinical scores improves prediction of stroke risk following TIA. Alongside clinical judgement, use of MRI has the potential to change the management of TIA patients and is the imaging modality of choice for this condition.

Intracranial Vessel Wall Imaging with Magnetic Resonance Imaging: Current Techniques and Applications

Vessel wall magnetic resonance imaging (VW-MRI) is a modern imaging technique with expanding applications in the characterization of intracranial vessel wall pathology. VW-MRI provides added diagnostic capacity compared with conventional luminal imaging methods. This review explores the principles of VW-MRI and typical imaging features of various vessel wall pathologies, such as atherosclerosis, dissection, and vasculitis. Radiologists should be familiar with this important imaging technique, given its increasing use and future relevance to everyday practice.

The 100 most cited articles in the Journal of NeuroInterventional Surgery

Background The Journal of NeuroInterventional Surgery (JNIS) published its first volume in 2009. Over the ensuing years, JNIS flourished and has published a considerable number of high-profile articles. Citation analysis is a method of quantifying various metrics related to scholarly publications. Objective To apply citation analysis to the 100 most cited papers in the history of JNIS. Methods The most cited articles in JNIS were identified by using the Web of Science database. The top 100 articles were ranked according to their number of citations. Further information was obtained for each article, including citations per year, year of publication, authorship, article topics, and article type and level of evidence. Results The total number of citations for the 100 most cited articles in JNIS ranged from 18 to 132 (median 26.0). Most articles (75%) were published between 2012 and 2015 and originated in the USA (79%). Eighteen authors have contributed five or more articles to the top 100 list. The most common topics are related to acute ischemic stroke and cerebral aneurysm. Conclusions This study highlights the influence of JNIS over its first decade by providing a comprehensive list of the 100 most cited articles and their authors as well as topics covered. This study also highlights the important factors driving the growth of JNIS.

E-132 Optimising resources for endovascular clot retrieval for acute ischaemic stroke using a discrete-event simulation model

Background Endovascular Clot Retrieval (ECR) is the standard of care for acute stroke due to a large vessel occlusion. It is a time critical and complex process involving many specialized care providers and resources. Maximizing patient benefit while minimizing cost of this service requires optimization of human and physical assets. The aim of this study was to develop a computer simulation of an ECR service designed to optimize resource allocation. Method Using Simmer-a Discrete Event Simulation (DES) software- as frequently employed in complex logistical operations, we have developed a comprehensive computational model that closely mimics the environment of an ECR service from presentation to emergency department to the angio suite. This model was tested using real data collected from a quaternary institution with ECR service. Results Our model assesses the impact of available services, and aids optimization of resource distribution and access, allowing comparison of various competing strategies. In this simulation, the numbers of different human or capital resources such as stroke physicians, neuro-interventionists, and angiography equipment can be varied to assess the impact on efficiency and availability of service delivery. Other factors and variables such as equipment breakdown, servicing or times taken during components of an individual stroke management pathway can also be integrated, to identify sources of systemic delay and cost-points, with a view to service improvement. Conclusion A novel computer simulation is proposed to assess resource allocation, directed at optimizing the timely, effective and equitable application of human and physical resources. This model can provide clinically important data to help existing ECR services, in targeting optimum service delivery and best patient outcomes. Disclosures S. Huang: None. J. Maingard: None. H. Kok: None. C. Barras: None. V. Thijs: None. R. Chandra: None. D. Brooks: None. H. Asadi: None.

Outcomes of endovascular thrombectomy with and without bridging thrombolysis for acute large vessel occlusion ischaemic stroke: Thrombectomy outcomes with and without thrombolysis in acute stroke

Endovascular thrombectomy (EVT) for management of large vessel occlusion (LVO) acute ischaemic stroke is now current best practice.

Audit of CT reporting standards in cases of intracerebral haemorrhage at a comprehensive stroke centre in Australia.

Multiple CT‐derived biomarkers that are predictive of intracerebral haemorrhage (ICH) growth and outcome have been described in the literature, but the extent to which these appear in imaging reports of ICH is unknown. The aim of this retrospective process audit was to determine which of the known predictors of ICH outcome was recorded in reports of the disease, with a view to providing reporting recommendations, as appropriate.

Tip of an Iceberg: Skull Fracture as an Adult Presentation of Encephalocraniocutaneous Lipomatosis

The severity of seizures presenting to the emergency department ranges from benign to life threatening. There are also a wide number of possible etiologies. Computed tomography (CT) emergency imaging may be required at presentation to elucidate a possible cause and assess signs of intracranial trauma. This case describes a serious seizure episode in a young man while on holiday. A CT brain showed a skull fracture as a consequence of seizure-related head trauma but unexpectedly there were image findings consistent with encephalocraniocutaneous lipomatosis. The important radiological features of encephalocraniocutaneous lipomatosis and a differential diagnosis are presented.