@shaheenn Welcome to Mayo Clinic Connect! I see you have had a few responses already, and @hopeful33250 has asked me to give my thoughts.

I don't have an abdominal aneurysm, but am in Stage 5 kidney failure. If the doctors have not given him the eGFR number [the filtration rate percentage] that would be helpful. In the past two years I have had several imaging procedures done, and even when the doctors ordered no contrast, I double checked with the technicians to make sure it was "no contrast". Impaired kidney function can be further hurt with the contrast material, because it is difficult for the kidneys to clear it out of your system. As @becky1024 told us, and we can each have different experiences.

If your brother does not have a nephrologist on his medical team, it might be a good thing to get an opinion from one before the procedure. Having good communication is critical, and understanding the pros and cons fully will help give him a basis for his decision.

Here is an article from the National Kidney Foundation about contrast dyes and our kidneys: https://www.kidney.org/atoz/content/Contrast-Dye-and-Kidneys#:~:text=CIN%20is%20a%20rare%20disorder,receiving%20dyes%20can%20develop%20CIN.
Let me know if I can help further and answer any questions.
Ginger