Ultrasound

When Is Ultrasound Needed?

Ultrasound is useful for a variety of conditions, including:

• Obstetric (related to pregnancy) uses for ultrasound
• Non-obstetric uses for ultrasound

Specialized ultrasound imaging procedures include:

• Echocardiography
• Doppler echocardiography
• Ultrasound for biopsy

Obstetric Uses For Ultrasound

One of the most common uses for ultrasound is to view the uterus (the muscular organ in a woman’s abdomen that holds the fetus) and fetus (unborn child) during pregnancy. Ultrasound scanning is often performed at about 16 to 18 weeks into the pregnancy.

• If the date of conception is known, the scan can demonstrate whether or not the fetus is of expected size. If the date of conception is unknown, or the mother is uncertain, ultrasound of fetal size can help establish the accurate date of conception.
• Ultrasound can reveal a multiple pregnancy (for example, twins or triplets).
• Ultrasound is valuable in identifying some fetal abnormalities.
• Congenital heart disease (malformation of the heart) can sometimes be detected, enabling both the parents and the doctor to prepare for specialized care during delivery.
• Ultrasound is used for amniocentesis, a procedure that uses a needle to remove amniotic fluid for analysis.

Some of the other conditions during pregnancy for which ultrasound is valuable include:

• Position of the placenta (special tissue that provides nutrients to the fetus)
• General health of the fetus
• Ectopic pregnancy (presence of an embryo outside the uterus)
• Impending miscarriage
• Early fetal death

Ultrasound also can help to view the fallopian tubes, ovaries and other reproductive organs in instances of infertility, or to look for cysts or other foreign objects.

Non-Obstetric Uses For Ultrasound

Ultrasound is used for many non-obstetric conditions or disorders, including the following:

• Scanning of the brain in a newborn
• Examining of the internal organs, including the appendix in possible appendicitis (rupture of the appendix)
• Scanning of the liver to determine cirrhosis (liver inflammation) and liver cysts (fluid filled sacs), abscesses (infections), or tumors (masses of cells)
• Locating gallstones in the gallbladder or bile ducts
• Scanning of the pancreas for cysts, tumors, or pancreatitis (inflammation of the pancreas)
• Evaluating the eyes
• Scanning of the kidneys for congenital defects, tumors, and hydronephrosis (swelling of the kidney due to urine outflow obstruction)
• Scanning of the thyroid gland, breasts, bladder, testicles, ovaries, spleen, and eyes for cysts, tumors, or foreign objects
• Identification of the cause of enlargement of the abdomen or other organs
• Investigation of tendon tears
• Review of the outcome of a procedure
• Determining if a person is a good candidate for angioplasty (reopening or reconstruction of a blood vessel) or other procedures

Echocardiography

Echocardiography is a specialized type of ultrasound that is used to look at the action and function of the heart.

This type of ultrasound is a major diagnostic technique that can detect structural and some functional abnormalities of the heart wall, valves, and large blood vessels. Blood flow across the valves can also be measured.

An echocardiography is especially valuable for studying disorders of the heart valves. Abnormal opening and closing of these valves can be detected because they differ from normal patterns of movement.

Other diagnostic uses of echocardiography include:

• Detection of congenital heart disease (a malformation of the heart or blood vessels near the heart)
• Detection of problems with the large blood vessels
• Detection of any enlargement or damage of the heart muscle, a condition called cardiomyopathy
• Swellings caused by weakening of the heart wall or the blood vessel walls (aneurysms)
• The presence of a blood clot in one of the chambers of the heart
• Pericarditis, a condition in which the pericardium, the membrane that covers the heart, becomes inflamed.

Doppler Echocardiography

Doppler echocardiography is a recently developed ultrasound technique that indirectly measures the flow velocity of blood as it passes through the heart. It is used in assessing malfunctioning valves in aortic stenosis (narrowing of the aortic valve opening) or mitral insufficiency (failure of the mitral heart valve to close properly) and in assessing patients with congenital heart disease.

Ultrasound For Biopsy

Another increasingly common use for ultrasound is in conjunction with fine-needle biopsy (inserting a very thin and hollow needle into an organ to remove tissue or fluid for examination). Ultrasound provides a real time, moving image. So, the image is valuable in helping to guide the needle accurately to a specific spot.