Groin arteries. Coloured coronal (frontal) MRA (magnetic resonance angiography) scan of healthy arteries (red) in the lower abdomen, groin and upper legs. The last part of the main body artery, the aorta, runs from top centre (near the kidneys) to upper centre (just above the groin). Here, it divides into the iliac arteries that run into the upper legs. Branches supply the internal tissues, with the main arteries continuing downwards as the femoral arteries. These become the popliteal arteries (not seen) at the knee. MRA is a type of magnetic resonance imaging (MRI) technique that highlights blood vessels without the need for X- rays or the injection of a radio-opaque dye.