digital subtraction angiography
Quick Summary
Digital subtraction angiography (DSA) is a medical imaging technique that uses X-rays and a contrast medium to visualize arteries and veins. This method is particularly useful for diagnosing blockages or narrowing in blood vessels.
In DSA, a contrast agent containing iodine is injected into the bloodstream. A computer then takes two sets of images: one before the contrast material is injected and one after. By subtracting the first image from the second, the computer removes the shadows cast by bones and soft tissues, making the blood vessels filled with contrast material stand out more clearly. This technique helps physicians identify issues like stenosis (constriction) or thrombosis (clot formation) in arteries, such as the carotid artery or pulmonary arteries.1
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