Coloured 3D computed tomography (CT) angiogram of the pelvis of a female patient with a pseudoaneurysm (bulge) of the right common femoral artery (left). A pseudoaneurysm is a localised collection of blood (haematoma) that forms as the result of a leaking hole in an artery. This pseudoaneurysm was due to bleeding associated with a puncture injury to the groin. Small pseudoaneurysms can clot and heal themselves, whilst larger ones may need treatment.