Digital subtraction angiography
Last reviewed: 23.04.2024
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A new technique for radiologic examination of blood vessels is digital subtraction angiography (DSA). It is based on the principle of computer subtraction (subtraction) of two images recorded in the computer's memory - pictures before and after the introduction of contrast medium into the vessel.
Thanks to computer processing, the final X-ray picture of the heart and vessels is of high quality, but the main thing is that it can be used to depict the vessels from the general image of the part of the body being examined, in particular to remove the interfering shadows of the soft tissues and skeleton and quantify hemodynamics. An essential advantage of DSA in comparison with other methods is the reduction of the required quantity of radiopaque substance, therefore it is possible to obtain a picture of the vessels with a large dilution of contrast medium. And this means that it is possible to introduce a contrast agent intravenously and in the subsequent series of images to obtain a shadow of the arteries without resorting to their catheterization. At present, almost everywhere, conventional angiography is replaced with digital subtraction angiography.
It should be noted that in connection with the development of other, alternative methods of visualization of vessels, in particular computer, magnetic resonance and ultrasound angiography and Dopper mapping, the frequency of angiography in clinical practice has significantly decreased.
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