Ultrasound uses high-frequency sound rather than radiation to image soft tissue. The 2D study is the standard diagnostic examination; the 4D study adds moving three-dimensional images, most often used in pregnancy.
Common examinations
- Pregnancy — dating, growth, position and fetal wellbeing
- Abdomen — liver, gallbladder, pancreas, kidneys and spleen
- Pelvis — uterus, ovaries, bladder and prostate
- Thyroid and neck lumps
- Breast lumps
- Scrotum
- Soft-tissue swellings and joints
Preparation
- Upper abdomen — do not eat for six to eight hours beforehand; the gallbladder is only assessable when full
- Pelvis or pregnancy — drink water and arrive with a full bladder unless told otherwise
- Everything else — no preparation needed
Check your appointment letter, and ring the department if the instructions are unclear. Coming unprepared is the commonest reason a scan has to be repeated.
