What are the indications?
Most commonly it is performed as an introduction to interventional procedure (like Angioplasty/stenting of the narrowed artery or embolization of the bleeding vessel in the kidney. The other indications include surgical mapping for kidney tumours or vascular malformation.
Same as for general angiography
Is there any additional risk?
Depending on intervention. Please refer to angioplasty/stenting or embolization.