Ultrasound Imaging

Ultrasound Imaging

Diagnostic medical ultrasound is a way to create images of anatomic areas for the purposes of measurement or diagnosis. It uses no radiation but instead transmits high frequency sound waves (2 to 12 MHz) into the body, and the returning echoes are processed by a computer into pictures which are interpreted by a radiologist. These sound waves are painless, and there are no known harmful effects at the low intensities used by modern diagnostic ultrasound equipment. Ultrasound cannot penetrate through bone, or gas in the intestines. It does pass readily through fluid. A gel is applied to the skin to conduct the sound waves from the transducer into the body.



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What preparation is needed?

See below for the specific preparation for a particular exam.

What should I wear?

Wear loose fitting, comfortable clothes. Depending on the exam, you may be asked to change into a gown.

How long will it take?

You should allow one hour, although your examination may be shorter. When the examination is finished, you will usually be asked to wait while the images obtained by the sonographer are shown to the radiologist. In some cases, the radiologist will also scan.

When can I resume normal activities?

Immediately after the exam.

How will my physician get the results?

A Via Radiology Seattle radiologist will provide a written interpretation of the images, which will be sent to the physician who ordered the test. Within several days your physician should contact you with the results.


Types of Ultrasound Imaging

Abdominal Ultrasound

Designed to look at the internal organs of the abdomen, including liver, spleen, gallbladder, bile ducts, pancreas, kidneys, and aorta. Typical reasons for your doctor to order an abdominal ultrasound include abdominal pain, question of gallstones, fluid (ascites) in the abdominal cavity, abdominal aortic aneurysm, kidney obstruction, and sometimes hernias or appendicitis.

Preparation: The evening before your exam, eat a low fat meal. After 9 PM, no further food, although fat free liquids are acceptable until midnight. After midnight and until your exam, nothing except your normal medications and a small amount of water to swallow them.

Pelvic Ultrasound

A pelvic ultrasound in a female is performed to evaluate the internal pelvic organs, including uterus and ovaries. Typical concerns that might cause your doctor to order a pelvic ultrasound include pelvic pain, abnormal bleeding, abnormalities of the ovary including cysts, and fibroids of the uterus.

Pelvic ultrasound in a female is usually done both through the lower abdominal skin (transabdominal) as well as through the vagina (transvaginal). A specialized ultrasound transducer is inserted into the vagina, either by you or by the technologist, to allow for better visualization of the uterus and ovaries than can usually be obtained transabdominally.

Preparation: Unless you are having only a transvaginal ultrasound, you will need to drink two 8 ounce glasses of water (or other clear non-carbonated liquid). Finish drinking this one hour prior to your scan. Do not empty your bladder before having the ultrasound.

Nuchal Translucency

First-trimester screening using both nuchal translucency (NT), an ultrasound exam that measures the thickness at the back of the neck of the fetus, and a blood test. The measurement can help your health care provider assess your baby’s risk for Down Syndrome and other chromosomal abnormalities.

Preparation: None.

Hysterosonography (also called Sonohysterography)

This is a variation of transvaginal ultrasound, and is performed after insertion of a thin flexible plastic catheter into the cervix. A sterile saline solution is introduced into the uterine cavity through this catheter, while scanning with transvaginal ultrasound. This can provide very detailed images of the endometrial lining of the uterus.

Obstetric Ultrasound

Obstetric ultrasound is used to evaluate all stages of pregnancy. The unborn baby (fetus) will be measured, which gives an estimate of its age and weight. When it is large enough, its anatomy can be carefully examined. In later pregnancy its growth over time can be followed. Other aspects of pregnancy such as the amount of fluid around the fetus and the placenta are also evaluated.

Preparation: If you are in your first 3 months of pregnancy, you will need to drink two 8 ounce glasses of water (or other clear non-carbonated liquid). Finish drinking this one hour prior to your scan. Do not empty your bladder before having the ultrasound.

If you are past the first three months of pregnancy, no specific preparation is required.

Thyroid Ultrasound

The thyroid gland is typically evaluated for reasons of enlargement (goiter) or a palpable nodule, or abnormal blood tests of thyroid function. The parathyroid glands (adjacent to the thyroid gland) are not usually seen, but may be enlarged and visible if there is an abnormal blood test suggesting abnormal parathyroid function.

Preparation: No specific preparation, but you will need to be able to lie on your back with your neck slightly extended backwards over a pillow.

Renal (Kidney) Ultrasound

Although the kidneys are evaluated as a part of an abdominal ultrasound, they may be examined also as a specific, more limited exam. The bladder in the pelvis is also examined.

Preparation: Do not empty your bladder prior to the exam.

Musculoskeletal Ultrasound (example: Shoulder, Hand, Foot and Finger)

Specialized ultrasound transducers, designed for high-resolution images of superficial tissues, can be used to look at the tendons of the rotator cuff of the shoulder, in cases of possible tendon injury. In cases of palpable lumps or trauma involving other superficial soft tissues, or foreign bodies such as a sliver or imbedded glass, ultrasound can often identify and characterize such abnormalities.

Preparation: None.

Transrectal Ultrasound

A specialized ultrasound transducer (probe) is inserted into the rectum about 3 inches to obtain images of the rectal wall. This is typically used to look at the integrity of the muscle wall of the anal sphincter in cases of incontinence or to evaluate a rectal tumor.

Preparation: Dulcolax suppository, 1-2 hours before your exam. This can be purchased over the counter at any local pharmacy.

Testicular Ultrasound

A specialized ultrasound transducer designed to evaluate superficial tissues will be used to obtain high resolution images of the testicles and adjacent structures, typically performed in cases of pain, infection, trauma, or question of palpable lumps or tumor.

Preparation: None.

Venous Ultrasound

This technique uses a specialized transducer designed for superficial tissues, and includes color Doppler flow measurements for evaluation of the veins of the arm or leg, in cases of suspected blood clot.

Preparation: None.


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