Answer: If the cardiologist performed the injection to view the bilateral extremities, you should only report 75716 (Angiography, extremity, bilateral, radiological supervision and interpretation). In other words, the cardiologist interprets information of the bilateral extremities when the runoff imaging is from the distal (above bifurcation) aorta.
You'll only report 75630 (Aortography, abdominal plus bilateral iliofemoral lower extremity, catheter, by serialography, radiological supervision and interpretation) when the cardiologist places the catheter at the level of the renals and provides one fluid injection. This is so he can view the abdominal through the femoral arteries bilaterally (at least to the common femoral). Don't miss: Multiple injections versus one fluid injection will help you determine which runoff imaging code to use. Remember: If the cardiologist provides only the professional component, be sure to include modifier 26 (Professional component).