Search results
Results from the WOW.Com Content Network
Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contrast image" or mask from subsequent images, once the contrast medium has been introduced into a ...
Magnetic resonance angiography (MRA) is a group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of arteries (and less commonly veins) in order to evaluate them for stenosis (abnormal narrowing), occlusions, aneurysms (vessel wall dilatations, at risk of rupture) or other abnormalities.
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing acute blood loss.
The goal of vascular interventional radiology and others who work in limb salvage is to minimize tissue loss by preserving direct blood flow to the affected limb by treating vessel blockages, controlling any infection and optimizing wound care. Increasingly, this can be accomplished with primary endovascular therapies before open surgery is ...
Critical closing pressure is the internal pressure at which a blood vessel collapses and closes completely. [1] When blood pressure falls below critical closing pressure, the vessel is unable to overcome external pressure (either from environment or vascular smooth muscle) and flow stops.
Degenerative changes that occur with age in the walls of large elastic arteries are thought to contribute to increased stiffening over time, including the disruption of lamellar elastin structures within the wall, possibly due to repeated cycles of mechanical stress; inflammation; [7] changes in arterial collagen proteins, partially as a ...
Endothelial activation is a proinflammatory and procoagulant state of the endothelial cells lining the lumen of blood vessels. [1] It is most characterized by an increase in interactions with white blood cells (leukocytes), and it is associated with the early states of atherosclerosis and sepsis, among others. [2]
Veins have a much higher compliance than arteries (largely due to their thinner walls.) Veins which are abnormally compliant can be associated with edema. Pressure stockings are sometimes used to externally reduce compliance, and thus keep blood from pooling in the legs.