Mortality associated with the occlusion of large vessels in acute ischemic stroke is particularly high despite best available medical therapy. Early and safe revascularization of the primary occlusion is correlated with good clinical result. We report two patients with acute ischemic stroke in whom the mechanical device Penumbra System was used for thrombolysis and embolectomy. The Penumbra Sys...

We present a novel algorithm for rendering physically-based soft shadows in complex scenes. Instead of casting shadow rays, we place both the points to be shaded and the samples of an area light source into separate hierarchies, and compute hierarchically the shadows caused by each occluding triangle. This yields an efficient algorithm with memory requirements independent of the complexity of t...

BACKGROUND Higher reperfusion rates have been established with endovascular treatment for acute ischemic stroke patients. There are limited data on the comparative performance of mechanical thrombectomy devices. This study aimed to analyse the efficacy and safety of the stent retriever device (Solitaire stent) by comparing procedure time, angiographic outcome, complication rate and long term cl...

BACKGROUND AND PURPOSE During focal cerebral ischemia, the ischemic penumbra or border-zone regions of moderate cortical blood flow reductions have a heterogeneous development of intracellular cortical acidosis. This experiment tested the hypotheses that (1) this acidosis is secondary to glucose utilization and (2) this intracellular acidosis leads to recruitment of potentially salvageable tiss...

The objective of this work was to measure the performance characteristics of a double-focus multileaf collimator (MLC) for intensity modulated radiation therapy (IMRT), specifically the variation in penumbra and leakage for narrow fields as a function of field position over a 20x27 cm space available for segmented MLC IMRT. Measurements were made with 6 MV x rays through a MLC containing 29 lea...

CT perfusion (CTP) is part of the initial evaluation of stroke patients, allowing differentiation between infarcted tissue and the ischaemic penumbra and helping in the selection of patients for endovascular treatment. This study assessed the reliability of the qualitative evaluation CTP maps in defining the ischemic penumbra and identified potential pitfalls associated with this technique. We ...

It is now widely accepted that not all brain cells die immediately after stroke. Surrounding a core of severe and rapid tissue injury, brain cell death evolves more slowly in a heterogeneous area that has been called the penumbra.1,2 In 1977, Astrup et al provided one of the first experimental demonstrations of the penumbra in a baboon model of cerebral artery occlusion.3 This region of brain i...

Within the ischemic penumbra, blood flow is sufficiently reduced that it results in hypoxia severe enough to arrest physiological function. Nevertheless, it has been shown that cells present within this region can be rescued and resuscitated by restoring perfusion and through other protective therapies. Thus, the early detection of the ischemic penumbra can be exploited to improve outcomes afte...

Whole brain computed tomography perfusion (CTP) has the potential to select eligible patients for reperfusion therapy. We aimed to find the optimal thresholds on baseline CTP for ischemic core and penumbra in acute ischemic stroke. We reviewed patients with acute ischemic stroke in the anterior circulation, who underwent baseline whole brain CTP, followed by intravenous thrombolysis and perfusi...

We examined the expression of protein kinase C isoforms in infarcted tissue, penumbra and contralateral brain tissue from 10 patients who died between 1-52 days after ischaemic stroke. Ten patients aged 61-89 years were used in the study. Tissue samples were assayed for protein kinase C activity using a non-radioactive method, and specific isoforms expression determined by Western blotting and ...