Final answer:
The femoral artery is the most common injection site for an abdominal angiogram due to its size and accessibility, despite the radial artery and others being used for pulse palpation or different procedures.
Step-by-step explanation:
The most often used injection site for an abdominal angiogram is the femoral artery. This artery is preferred due to its accessibility and size, which makes it easier to introduce a catheter for the angiography. While sites such as the radial artery, brachial artery, and others can be used for pulse palpation or different procedures, the femoral artery is commonly selected as the entry point for an abdominal angiogram to access the abdominal aorta and its branches which include the superior and inferior epigastric arteries, the deep femoral artery, and other major vessels within the abdominal and lower limb regions.