DSA angiography shows that the black part is not a blockage.
DSA angiography is one of the commonly used clinical auxiliary examinations, which is the gold standard for clarifying stenosis in blood vessels. The examination involves injecting a contrast agent into the corresponding blood vessel via an artery and observing the filling of the contrast agent in the blood vessel under X-ray. The contrast medium appears as a high-density shadow under X-ray, which is the black color presented on the film, so the black part is not a blockage.
Stenosis appears as a filling defect in the vessel on DSA, while a completely occluded vessel will not show up on DSA. To accurately determine the results of DSA angiography, you need to have a good understanding of the vessel morphology, alignment, etc. It is recommended that you seek medical attention in a timely manner so that you can be evaluated by a medical professional and know the next step in your treatment.