Introduction: Stereotactic radiosurgery (SRS) is one of the conformal radiotherapy methods and Gamma Knife is a non-invasive SRS technique to treat intracranial lesions with 201 Co- 60 sources without need to surgery and bleeding. Beam penumbra phenomenon leads to irradiation outside the field and normal tissues. Therefore, considering it is momentous to attain the acceptable t...

BACKGROUND The ability to quickly and efficiently identify the ischemic penumbra in the acute stroke clinical setting is an important goal for stroke researchers and clinicians. Early and accurate identification of potentially salvageable versus irreversibly infarcted brain tissue may enable selection of the most appropriate candidates for early stroke therapies and identify patients who may st...

BACKGROUND AND PURPOSE Prediction of the regions of the ischemic penumbra that are likely to progress to infarction is of great clinical interest. Whether lowered apparent diffusion coefficient (ADC) values were present in the ischemic penumbra of patients presenting with acute ischemic stroke and were specific to regions of the penumbra that proceeded to infarction was investigated. METHODS ...

Shadows serve as e ective cues for a user to recognize spatial relations among objects in 3D space. However simple shadows typically used in 3D interfaces are often insu cient for the purpose, and rendering of shadows with real penumbra are not only too costly for interactive interfaces, but also do not enhance their capabilities as spatial cues. Our proposal, layered penumbra is a new interact...

Duration and extent of penumbra determine the window and brain volume in which interventions may save injured tissue after stroke. Understanding the penumbra in animals is necessary in order to design models that translate to effective clinical therapies. New Zealand white rabbits were embolized with aged autologous clot (n = 23) or insoluble microspheres (n = 21). To examine effects of treatme...

Neuronal apoptosis is mediated by intrinsic and extrinsic signaling pathways such as the membrane-mediated, mitochondrial, and endoplasmic reticulum stress pathways. Few studies have examined the endoplasmic reticulum-mediated apoptosis pathway in the penumbra after traumatic brain injury, and it remains unclear whether endoplasmic reticulum stress can activate the caspase-12-dependent apoptoti...

BACKGROUND AND PURPOSE Patient selection for acute stroke therapy based on physiology rather than on time may lead to expansion of the therapeutic window, improved outcomes, and fewer side effects than currently achieved. This approach requires early determination of both irreversible (core) and reversible (penumbra) ischemia in acute stroke. METHODS Using established perfusion thresholds, we...

Shadows serve as e ective cues for a user to recognize spatial relations among objects in 3D space. However simple shadows typically used in 3D interfaces are often insu cient for the purpose, and rendering of shadows with real penumbra are not only too costly for interactive interfaces, but also do not enhance their capabilities as spatial cues. Our proposal, layered penumbra is a new interact...