What It Is

A pelvis X-ray is a safe and painless test that uses a small amount of radiation to take a picture of the pelvic bones, which surround the hip area.

During the examination, an X-ray machine sends a beam of radiation through the pelvis and an image is recorded on special film or a computer. This image shows the bones of the pelvis, which include the two hip bones, plus the sacrum and the coccyx (tailbone).

The X-ray image is black and white. Dense body parts that block the passage of the X-ray beam through the body, such as bones, appear white on the X-ray image. Softer body tissues, such as muscles and fat, allow the X-ray beams to pass through them and appear darker.

An X-ray technician takes the X-rays in the X-ray department of a hospital or outpatient radiology center. One to two pictures are usually taken of the pelvis, one with the legs straight from the front (anteroposterior or AP view) and one with the legs bent from the side (lateral view). The X-rays are taken while the patient is lying flat on his or her back.

Why It's Done

A pelvic X-ray can help find the cause of symptoms such as pain, swelling, or deformity in the pelvic, hip, or upper leg regions, and can detect broken bones after an injury.

If pelvic surgery is required, an X-ray may be taken to plan for the surgery and to assess the results of the operation. Also, pelvic X-rays may detect other problems such as cysts, tumors, and later-stage infections of the pelvic bones.

Preparation

This X-ray doesn't require any special preparation. Your child may be asked to remove some clothing, jewelry, or any metal objects that might interfere with the image.

If your daughter is pregnant, it is important to tell the X-ray technician or her doctor. X-rays are usually avoided during pregnancy because there's a small chance the radiation may harm the developing baby. But if the X-ray is necessary, it will be done in the safest way possible.

Procedure

Although the procedure may take 10 minutes or longer from start to finish, actual exposure to radiation is usually less than a few seconds.

Your child will be asked to enter a special room that will contain a table and a large X-ray machine hanging from the ceiling or wall. Parents are usually able to accompany their child to provide reassurance.

If you stay in the room while the X-ray is being done, you'll be asked to wear a lead apron to protect certain parts of your body. The technician will position your child on the table, then step behind a wall or into an adjoining room to operate the machine. Older kids will be asked to stay still for a couple of seconds while the X-ray is taken; infants may require some gentle restraint. Keeping still is important to prevent blurring of the X-ray image.

If your child is in the hospital and can't easily be brought to the radiology department, a portable X-ray machine can be brought to the bedside. Portable X-rays are sometimes used in emergency departments, intensive care units (ICUs), and operating rooms.

What to Expect

Your child won't feel anything as the X-ray is taken. The X-ray room may feel cool due to air conditioning used to maintain the equipment.

The positions required for the X-ray can feel uncomfortable, but they need to be held for only a few seconds. If your child is having pain and can't stay in the required position, the technician might be able to find another position that's easier. Babies often cry in the X-ray room, especially if they're restrained, but this won't interfere with the procedure.

After the X-ray is taken, you and your child will be asked to wait a few minutes while the image is processed. If it is blurred or unclear, the X-ray may need to be redone.

Getting the Results

The X-ray will be looked at by a radiologist (a doctor who is specially trained in reading and interpreting X-ray images). The radiologist will send a report to the doctor, who will discuss the results with you and explain what they mean.

In an emergency, the results of an X-ray can be available quickly. Otherwise, they're usually ready in 1-2 days. In most cases, results can't be given directly to the patient or family at the time of the test.

Risks

In general, X-rays are very safe. Although there's some risk to the body with any exposure to radiation, the amount used in a pelvis X-ray is small and not considered dangerous. It's important to know that radiologists use the minimum amount of radiation required to get the best results.

Developing babies are more sensitive to radiation and are at greater risk for harm, so if your daughter is pregnant, make sure to inform her doctor and the X-ray technician.

Helping Your Child

You can help your young child prepare for a pelvis X-ray by explaining the test in simple terms before the procedure. It may help to explain that getting an X-ray is like posing for a picture.

You can describe the room and the equipment that will be used, and reassure your child that you'll be right there for support. For older kids, be sure to explain the importance of keeping still while the X-ray is taken so it won't have to be repeated.

If You Have Questions

If you have questions about why the pelvis X-ray is needed, speak with your doctor. You can also talk to the X-ray technician before the procedure.

Reviewed by: Yamini Durani, MD
Date reviewed: August 2011