There are 2 techniques,�direct method�and�indirect method, used to investigate renal arterial supply. Both ideally are used in conjuction with each other, however, in circumstances where the renal artery is not seen in its entirety then the indirect approach alone can give an indication of vascular disease.
The following examinations are done with Level 2 - foetal life (foetal heart beat), foetal movements, number of foetus, presentation and lie of foetus, amniotic fluid volume, placental location, foetal measurements (e.g. BPD, HC, FL, AC and other foetal parameters), foetal anatomy (including the foetal head, face, ears, neck, chest, abdomen, and extremities, a basic 4 chamber view of the heart, the foetal spine, stomach, kidneys, bladder, umbilical cord insertion and number of vessels).
Ultrasound Basic Obstetrical (also known as level 2 ultrasound) is more extensive than the limited ultrasound, and it takes normally between 30 and 60 minutes. It is done to answer a whole set of pre-defined questions and it also looks for specific foetal malformations, which in general the limited ultrasound does not do. This is usually the �routine� ultrasound most patients have at 18-20 weeks and it is done at that time because the foetal anatomy is seen best, though it can also be done at other times too.