digital subtraction angiography

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angiography

 [an″je-og´rah-fe]
radiography of vessels of the body after injection of contrast material; see also arteriography, lymphangiography, and phlebography. Called also vasography.
digital subtraction angiography radiographic visualization of blood vessels, with images produced by subtracting background structures and enhancing the contrast of those areas that change in density between a preliminary “mask” image and subsequent images.

dig·i·tal sub·trac·tion an·gi·og·ra·phy (DSA),

computer-assisted radiographic angiography that permits visualization of vascular structures without superimposed bone and soft tissue densities; subtraction of images made before and after contrast injection removes structures not enhanced by the contrast medium. Other image processing can be performed. Contrast material may be injected intravenously or in a lower-than-usual amount intraarterially.

digital subtraction angiography (DSA)

a method in which radiographic images of blood vessels filled with contrast material are digitized and then subtracted from images obtained before administration of the material. The method increases the contrast between the vessels and the background.

digital subtraction angiography

Radiology A diagnostic technique that uses video equipment and computers to enhance images obtained with conventional angiography

dig·i·tal sub·trac·tion an·gi·og·ra·phy

(DSA) (dij'i-tăl sŭb-trak'shŭn an'jē-og'ră-fē)
Computer-assisted radiographic angiography permitting visualization of vascular structures without superimposed bone and soft tissue density; images made before and after contrast injection allow subtraction (separation and removal) of opacities not enhanced by the contrast medium Other image-processing can be performed. Contrast material may be injected intravenously or in lower-than-usual amounts intraarterially.
See: digital radiography

digital subtraction angiography

A method of imaging blood vessels that eliminates unwanted detail. Two digitized images are made, before and after injecting a radio-opaque dye. A negative image of one is then combined with the other, so that only differences between the two show up-in this case the dye in the vessels.