Ultrasonography is the production of images of the internal organs by passing very high-pitched sound waves into the body. These are inaudible to the human ear.

The sound waves, on hitting the organs, produce 'echoes' which are built up into an image on a screen by a computer.

Uses
It is used in the detection of disease in the gall bladder, liver, pancreas, and kidneys e.g. stones, dilated ducts.

Preparation
1. Abdominal ultrasound
You will be asked to have nothing to eat or drink for 6 hours prior to the procedure, but you may take your usual medication.

If the gall bladder is being examined, the previous day's supper must have been fat-free.

2. Pelvic ultrasound
The bladder must be full so you should drink lots of fluid about 1 hour before the examination and not pass urine before the test.

The Examination
Whilst lying comfortably on a couch, the radiologist will put some jelly on your abdomen and move a transducer (sound wave transmitter) over it. The examination takes about half an hour. A pelvic ultrasound often involves a separate vaginal examination in which a small probe is introduced into the vagina which also transmits sound waves producing pictures on the screen. This is not painful but may feel a little uncomfortable.

The radiologist can interpret these pictures and send a report to your doctor.

After the Test
You may eat and drink normally.