Indications for Ultrasound
Ultrasound is valuable in many circumstances. There are situations where physicians can't get information in any other way, such as during pregnancy. The safety of the sound, coupled with the incredible images of the fetus it produces, makes ultrasound the test of choice.
For gallbladder disease, ultrasound is standard. CT scan and ultrasound work together in other parts of the abdomen. Ultrasound is still standard in the female pelvis. From the patient's perspective, if you have ever had a contrast venogram where the dye was injected into a vein in your foot, you will appreciate the value of the noninvasive ultrasound study that can make the same reliable diagnosis in a fraction of the time with no contrast and no needles.
Prostate biopsies are most often performed under ultrasound guidance and ultrasound is used to examine the blood flowing through the carotid artery in the neck, which nourishes the brain. It also is often used as the first line of tests for appendicitis.
Ultrasound Procedure
What actually happens during an ultrasound depends on the type of test you are going to have. One of the most common studies is the abdominal ultrasound. To prepare for this test, the ultrasound technologist will explain the test and ask you a number of questions. You will be asked to climb up on an examining table after you have removed whatever clothing is necessary.
Next will come the jelly, which is a water-soluble substance. If it hasn't been warmed up, it will feel cold. The technologist will then scan by sliding the transducer over the areas of interest. Because there is so much gas on the left side of the abdomen, the technologist will usually focus on the right side where the liver offers a "window" into the abdomen. You will be asked to take deep breaths so that certain structures like the gallbladder come into view. This may go on for some time. If the technologist forgets to tell you to breathe, by all means take a breath.
The radiologist will notify you about the results of the ultrasound. If you don't hear from the radiologist, contact your primary care physician to find out the results.
Whereas in the upper abdomen, the liver is the acoustic window; in the pelvis, it is the bladder. To perform a pelvic ultrasound, most departments first do a study over the lower abdomen with a dilated urinary bladder, meaning you have to have a full bladder. You also may have a transvaginal exam, which is done by inserting a probe into the vagina and scanning the pelvic structures. These transvaginal studies are very well tolerated, except in the young and in the elderly, and they provide much more detailed information about the uterus and ovaries.
If you are going to have a Doppler study (an ultrasound that studies movement) for your carotid arteries or a Doppler study has been added to your abdomen and pelvis ultrasound, you will also probably hear the sound as well. The pitch of the sound tells the technologist a lot about the flow of blood in whatever structure is being imaged.
There are no significant risks or side effects to ultrasound.
