Sound waves (used in ultrasound), travel more effectively through liquids than through other body parts or air. If the bladder is full, it facilitates a passage of sound waves and acts as a “window” to see the uterus and ovaries lying behind the bladder better.

Air is introduced into the stomach when you eat, drink or chew gum. Ultrasound waves don’t penetrate well through air, which makes it more difficult to see target organs. Having food may also cause the gall bladder to contract, making it difficult to examine the gallbladder.

A radiologist is a specialist doctor who uses different imaging technologies (such as x-ray radiography, ultrasound, CT and MRI) to diagnose diseases or injuries.

A radiographer is a qualified and registered professional person who operates the different imaging equipment to produce medical images.