Ultrasound
Diagnostic ultrasound uses high frequency sound (2 to 20MHz) to provide high resolution images of the human body. It does not use ionizing radiation such as x-rays. Therefore, it is a safe, non-invasive means of creating cross sectional images of the human body. It is also a relatively cost-effective means of imaging.
Clinical Applications
Ultrasound has many clinical applications including obstetrics, abdominal, pelvic, vascular and musculoskeletal.
In obstetrics ultrasound can be used to assess normal fetal anatomy, biometry, number, and position. It can also be used to assess placental position and amniotic fluid volume. Vascular ultrasound enables real time imaging of blood flow thus making it possible to discern stenoses in the arteries, or thrombosis of the veins. Musculoskeletal ultrasound allows us to image tendons, muscles and nerves for degeneration or tears. In the abdomen and pelvis ultrasound can be used to assess the liver, gallbladder, kidneys, spleen, pancreas, prostate, uterus, ovaries and testes. Ultrasound can also be valuable in assessing the breast and thyroid gland. Ultrasound images can also be obtained in 3D to assist in diagnosis.
Accredited Sonographers
Ultrasound imaging is performed by or under the supervision of an accredited sonographer. Sonographers gain their accreditation through the Australian Sonographer Accreditation Registry (ASAR) after obtaining a (two-year part time) post graduate qualification in Medical Ultrasound.
How long does the ultrasound take?
Most ultrasound examinations take about 30 minutes to perform. However, some vascular examinations can take considerably longer than this – up to 90 minutes.
Preparation
This will depend on the ultrasound procedure being performed.
Ultrasound Pregnancy or Pelvis: A full bladder is required for this examination. Drink 500mls of clear fluid 1 hour before your appointment. Exception: In patients undergoing only a Transvaginal Ultrasound and in cases of advanced pregnancy (after 24 weeks) only moderate bladder filling is required.
Ultrasound Upper Abdomen: Prior to this examination you need to fast for 8 hours. You may drink clear fluids.
Ultrasound Thyroid, Breast, Scrotum: No preparation required.
Ultrasound Carotid, Leg Veins (DVT or CVI), Arm Veins, Arm Arteries: No preparation required.
Ultrasound Leg Arterial, Renal Arteries, Abdominal Doppler: Prior to this examination you need to fast for 8 hours. You may drink clear fluids.
Ultrasound Musculoskeletal Ultrasound: No special preparation required.
Safety Issues
As mentioned diagnostic ultrasound is safe and does not use ionising radiation such as x-rays. That being the case it is important that ultrasound is used only for diagnostic medical purposes. For example, it should not be used solely for the purposes of entertainment or fetal sex determination (unless medically justified).