Angiography is a diagnostic procedure, carried out by assistance of an MRI system, CT or a digital subtraction angiography device (DSA) for the depiction of vessels. MR angiography can take place with or without the application of a contrast agents, whereas CT or digital subtraction angiography necessitate the application of a contrast agent.

Firstly, an X-ray image without a contrast agent is taken. During and after the following contrast agent application, several further images are taken. Because the digitized images without a contrast agent are subtracted from the images showing the vascular status with a contrast agent, the procedure is called digital subtraction angiography. This way elements of the images are removed that are not necessary for the evaluation or that would make it difficult to evaluate the images, for example, bones.



Indication angiography: when is angiography performed?

Angiography takes place if vascular diseases seem to be the cause of complaints. During angiography, veins, arteries, lymph vessels or vascular prostheses can be examined. Examples for the indication of angiography are:

How is digital subtraction angiography carried out?

Prior to the examination, it is of utmost importance to evaluate if patients undergoing angiography have a blood coagulation disorder/coagulopathy (blood test), an allergy to contrast agents, an illness making the performance of an angiography difficult or impossible, or if they take drugs manipulating the angiography.

The day of the examination, patients must have an empty stomach and are not allowed to smoke for a couple of hours before the examination. After disinfecting the skin and administration of local anesthesia, if necessary, the contrast agent is injected directly into a blood vessel or through a catheter guided to the blood vessel to be examined. Given a catheter application, also therapeutic procedures are possible, e.g., vascular dilatation by a balloon, stent placement or glue usage for the repair of damaged vessels.

At the end of the examination/treatment, the wound is sterilely covered. Depending on the examination or treatment, it can be necessary that patients do not stand up but lay low and stay one day for observation.