House Calls runs every other Saturday. Today's column is written by Catherine Balck, an ultrasound technologist at Sutter Coast Hospital.

Some people are surprised when their doctor orders an ultrasound exam, because they thought ultrasound was only used for viewing babies inside of mothers.

Actually, ultrasound exams are used to look at and evaluate almost all areas of the body. For example, we regularly use ultrasound to see the abdomen, pelvis, kidneys, bladder, scrotum, breast, all sorts of blood vessels and of course babies at various stages of development.

So what exactly is ultrasound? Diagnostic ultrasound is a way to look

at an organ of the body by using high frequency sound waves (way above

what your ear can hear) to create an image. The way this works is that

the ultrasound machine uses a wand or probe to create the sound waves

and send them into the body. These sound waves hit and then bounce off

of the body part or organ that is being examined. The data from the

returning sound waves are then used to make images of that body part or


Like any diagnostic method, ultrasound has both benefits and

limitations. One of the big benefits is that ultrasound allows the

medical provider to see inside the body in "real time." The technologist

and doctor can see blood as it flows, or see a needle inserted into

tissue for a biopsy. Ultrasound also helps doctors look at a patient's

organs to see if there is a disease or injury. Plus, because ultrasound

makes images without using any radiation, it helps reduce the amount of

radiation that a patient will receive over a lifetime.

A big limitation of ultrasound is that it can't create clear images

of organs that contain air (like bowel) or bone. This is why lung, bowel

and brain tissues are not usually imaged with ultrasound. When a

patient has a large body size the images produced are not as detailed as

they are with thinner patients. In addition, to get the clearest images

patients may need to slow their breathing or hold their breath - but

this is very hard or impossible for patients who are very young or very


So what happens when you have an ultrasound exam? First, it does not

hurt. Although you may feel some pressure from the ultrasound wand, you

will not feel the sound waves. When you arrive for your exam you will be

greeted in the Diagnostic Imaging Department by the technologist and

escorted to the ultrasound suite. The technologist will explain the

exam, ask some questions about your symptoms, and then have you lie down

on a bed. The area to be imaged will be exposed, and the technologist

will apply warm gel to the imaging wand or your body. The purpose of the

gel is to ensure all of the sound waves enter your body and don't get

"lost" at your skin.

The technologist will take multiple images of one or more areas.

Some exams require evaluation of up to 10 organs; others might be

focused only on your area of pain. Once the technologist has taken the

required images, he or she will write up a summary of the images and

submit it to the radiologist. The radiologist will review the images and

any prior diagnostic exams that are relevant and create an official

report that is sent to your doctor. Your doctor should review the

results of the exam with you and explain any findings. Together, you and

your doctor will determine whether additional diagnostic imaging is

required and/or discuss a treatment plan to resolve your condition.

The technology used by ultrasound machines continues to improve, and

there will be more ways in the future for ultrasound to assist in the

diagnosis of disease. Patients should not be surprised if their doctor

wants to use ultrasound to help assess their symptoms. After all,

ultrasound is not just for babies anymore!

Email suggestions for future House Calls columns to Beth Liles at Sutter Coast Hospital,