Ultrasound is a procedure that uses high-frequency sound waves to view internal organs and produce images of the human body. The human ear cannot hear the sound waves used in an ultrasound. An ultrasound may also be called a sonogram.
Things to know:
- Ultrasound is a noninvasive, painless imaging technique
- Ultrasound is widely available, low cost and easy to use
- Because it does not use radiation, the side effects of radiation are not an issue. It is the preferred technique for monitoring pregnant women and their unborn children
- Real-time images are generated by ultrasound, so it is a good tool for guiding invasive procedures like needle biopsies
- Ultrasound can display the movement and actual function of the body's organs and blood vessels
- There are no known harmful effects of standard ultrasound imaging
- The main limitation of ultrasound imaging is that it does not reflect clearly from bone or air, therefore, other imaging techniques are preferred for areas such as the lungs and the bones
An obstetric ultrasound is used to visualize the embryo or fetus in its mother's uterus. This procedure is often a standard part of routine prenatal care.
There are two types of obstetrical ultrasound. Traditional obstetric ultrasounds, or transabdominal ultrasounds, are done by placing a transducer, (a probe that emits high frequency sound waves), on the abdomen of the pregnant woman. The other type is called a transvaginal ultrasound, where the probe placed in the woman's vagina. Transvaginal ultrasounds usually produce clearer pictures than transabdominal ultrasounds in early pregnancy.
Obstetric ultrasound is performed for a variety of reasons, which include but are not limited to:
- Early pregnancy detection
- Dating and growth monitoring
- Fetal sex determination
- Abnormality screening
This simple test uses sound waves to image the thyroid. The sound waves are emitted from a small hand-held transducer which is passed over the thyroid. A lubricant jelly is placed on the skin so that the sound waves transmit easier through the skin and into the thyroid and surrounding structures. This test is quick, accurate, painless, and completely safe. It usually takes only about 10 minutes.
An abdominal ultrasound uses sound waves to produce a picture of the organs and other structures in the upper abdomen. Occasionally a specialized ultrasound is ordered for a detailed evaluation of a specific organ, such as a kidney ultrasound.
An abdominal ultrasound can evaluate the:
- Abdominal aorta, which is the large blood vessel (artery) that passes down the back of the chest and abdomen
- Liver, which is the large dome-shaped organ that lies under the rib cage on the right side of the abdomen
- Gallbladder, which is the saclike organ beneath the liver
- Spleen, which is the soft, round organ that helps fight infection and filters old red blood cells
- Pancreas, which is the gland located in the upper abdomen
- Kidneys, which are the pair of bean-shaped organs located behind the upper abdominal cavity
Renal ultrasound uses sound waves to produce a picture of the kidneys and bladder.
It can be used in the evaluation of a variety of complaints and conditions.
- Determine the source of abdominal pains, such as kidney stones
- Help in the evaluation of infection in the kidneys or bladder
- Help to identify congenital abnormalities (abnormalities you have been born with) of the renal tract
- Help in the evaluation of problems related to the prostate gland
- Help in identifying injuries to the kidneys and bladder after accidents
Renal ultrasound uses sound waves to produce a picture of the kidneys and bladder. It can be used in the evaluation of a variety of complaints and conditions. Doppler ultrasound measures how sound waves reflect off of moving objects. A wand bounces short bursts of sound waves off of red blood cells and sends the information to a computer. Doppler ultrasound produces two-dimensional color images that show if blood flow is affected by problems in the blood vessels, such as cholesterol deposits.
Kidney Transplant Doppler
Ultrasound of the kidney (renal) transplant uses sound waves to obtain pictures of the transplanted kidney. Color Doppler is used to check the overall blood flow of the kidney, and spectral Doppler checks certain places within a blood vessel. The blood vessels inside the kidney are checked, as are the vessels leading to and from the kidney.
A testicular ultrasound uses sound waves to produce pictures of the testicles and scrotum.
Testicular ultrasound is done to:
- Evaluate a mass or pain in the testicles
- Identify and monitor infection or inflammation of the testicles
- Identify twisting of the spermatic cord
- Monitor for recurrence of testicular cancer
- Locate an undescended testicle
- Identify fluid in the scrotum, fluid in the epididymis, blood in the scrotum, or pus in the scrotum
- Guide a biopsy needle for testicular biopsy when testing for infertility
- Evaluate an injury to the genital area
The primary use of breast ultrasound today is to help diagnose breast abnormalities detected by a physician during a physical exam and to characterize potential abnormalities seen on a mammogram. Ultrasound imaging can help to determine if an abnormality is solid (which may be a non-cancerous lump of tissue or a cancerous tumor) or fluid-filled (such as a benign cyst). Ultrasound can also help show additional features of the abnormal area.
Ultrasound is also used to assist a physician in performing a biopsy. When an ultrasound examination cannot characterize the nature of a breast abnormality, a physician may choose to perform an ultrasound-guided biopsy. Because ultrasound provides real-time images, it is often used to guide biopsy procedures.
Ultrasound-guidance can be used to assist physicians in obtaining tissue samples from the breast in three different biopsy procedures: a cyst aspiration, a fine needle aspiration and a core needle biopsy.
A pelvic ultrasound uses sound waves to create pictures of the organs and structures within the female pelvis. A pelvic ultrasound allows quick visualization of the female pelvic organs and structures including the uterus, cervix, vagina, fallopian tubes, and ovaries.
Pelvic ultrasound may be performed using one or both of two methods:
- Transabdominal (through the abdomen) - a transducer is placed on the abdomen using the conductive gel
- Transvaginal (through the vagina) - a long, thin transducer is covered with the conducting gel and a plastic/latex sheath and is inserted into the vagina
The type of ultrasound procedure performed depends on the reason for the ultrasound. Only one method may be used, or both methods may be needed to provide the information needed for diagnosis or treatment.
Ultrasound assessment of the pelvis may include, but is not limited to, the following:
- Size, shape, and position of the uterus and ovaries
- Thickness, echogenicity (darkness or lightness of the image related to the density of the tissue), and presence of fluids or masses in the endometrium, myometrium (uterine muscle tissue), fallopian tubes, or in or near the bladder
- Length and thickness of the cervix
- Changes in bladder shape
- Blood flow through pelvic organs
- Assessing certain fetal conditions
A pelvic ultrasound may also be used to diagnose and assist in the treatment of the following conditions:
- Abnormalities in the anatomic structure of the uterus, including endometrial conditions
- Fibroid tumors (benign growths), masses, cysts, and other types of tumors within the pelvis
- Presence and position of an intrauterine contraceptive device (IUD)
- Pelvic inflammatory disease (PID) and other types of inflammation or infection
- Postmenopausal bleeding
- Monitoring of ovarian follicle size for infertility evaluation
- Aspiration of follicle fluid and eggs from ovaries for in vitro fertilization
- Ectopic pregnancy (pregnancy occurring outside of the uterus, usually in the fallopian tube
- Monitoring fetal development during pregnancy
A hysterosonogram is a procedure uses sound waves to create images of the inside of the uterus to check for abnormalities. This procedure uses transvaginal ultrasound.
A hysterosonogram can be a valuable diagnostic test for a wide variety of problems. It can identify abnormalities in the uterus, which can be very useful in finding underlying causes for those who suffer from dyspareunia (pain during sexual intercourse), reproductive problems such as infertility or frequent miscarriage, or menorrhagia (uncommonly heavy or painful menstrual periods), and can help doctors identify uterine fibroids, polyps, or other growths, abnormalities, or lesions in the uterine wall.
Carotid ultrasound is a painless and harmless test that uses sound waves to create images of the insides of the two large arteries in the neck.
A standard carotid ultrasound shows the structure of your carotid artery. A carotid ultrasound test may also include a Doppler ultrasound. Doppler ultrasound is a special ultrasound that shows the movement of blood through the blood vessels.
Arterial Doppler Ultrasound
The Arterial Doppler ultrasound uses sound waves to produce images on a monitor for the purpose of evaluating the arterial blood flow to the upper extremities (arms) and lower extremities (legs). The Arterial Doppler study is able to demonstrate blocked or reduced blood flow through the major arteries of the arms and legs.
It is used to evaluate:
- Numbness and tingling sensations in the hands, arms, feet and legs
- Sensation of fatigue and heaviness in the arms and legs
- To investigate the possibility of thoracic outlet syndrome
Lower extremity venous Doppler/DVT study evaluates how the venous blood flows through the vein of the leg. Upper extremity venous Doppler/DVT study evaluates how the venous blood flows through the vein of the arm.
A venous ultrasound looks for:
- Blood clots especially in the veins of the leg
- Evaluate the narrowing of vessels and blood flow in the varicose vein and as a precursor for endovenous vein ablation
- Placement of a needle or catheter
- Mapping out the veins in the legs or arms for bypass of an area of disease
- Examine the vessels for dialysis
Thoracentesis is a procedure to remove fluid from the space between the lungs and the chest wall called the pleural space. An ultrasound will be performed prior to the procedure to help identify the location of the fluid. After the fluid is located, a needle (and sometimes a plastic catheter) is inserted through the chest wall, and the fluid is removed. This pleural fluid may be sent to a lab to determine what may be causing the fluid to accumulate in the pleural space.
Thoracentesis may be done to:
- Determine the cause of excess pleural fluid
- Relieve shortness of breath and pain caused by a pleural effusion
Paracentesis is a procedure to take out fluid that has collected in the belly. This fluid buildup is called ascites. Ultrasound is used to determine the location of the fluid in the belly, and then a needle is inserted into the belly. The fluid is then removed and sent to the lab to be studied to determine the cause of the fluid buildup.
Paracentesis may be done to:
- Find the cause of fluid buildup in the belly
- Diagnose an infection in the peritoneal fluid
- Check for certain types of cancer, such as liver cancer
- Remove a large amount of fluid that is causing pain or difficulty breathing or that is affecting how the kidneys or the intestines (bowel) are working
- Check for damage after a belly injury