FREQUENTLY ASKED QUESTIONS - Fluoroscopy - Parents
Imaging allows physicians see inside of the body to help diagnose disease and monitor treatments. Fluoroscopy is one type of imaging that uses ionizing radiation to create the images. The following information will help parents and caregivers understand some of the issues surrounding this topic.
What is medical radiation?
There are several different ways radiation can be used to help children medically. Radiation can be used for imaging or for therapy. Imaging techniques using radiation include X-rays, computed tomography (CT) scans, angiograms and radionuclide (nuclear medicine) studies. Examples of therapeutic techniques include radiation for the treatment of cancer or an overactive thyroid gland, and opening blocked vessels with a small balloon (angioplasty). Interventional radiology may be used for diagnosis or for treatment of medical conditions.
What is an xray?
X-rays are invisible beams of radiation that pass through the body and are removed by different tissues or organs to create images. The resulting images are 2- or 3-dimensional pictures that show bones, air-filled, and solid organs. X-rays can be used to create still pictures, like a camera, or to view the internal organs of the body in motion, similar to a video camera. The technique of using X-rays to view the internal organs in motion is called fluoroscopy. X-rays are a form of ionizing radiation, which means that in high doses this radiation can cause damage to living tissue. Diagnostic imaging uses low and often very low doses of ionizing radiation.
What is fluoroscopy used for in infants and children?
Fluoroscopy is a very useful imaging method for evaluating the structure and function of some of the internal organs of the body. Organs that have motion are best evaluated by techniques like fluoroscopy that can illustrate what is happening in the organ. Since most of the organs in the body have a similar density on X-rays, the organs will not be clearly visible with fluoroscopy unless they are filled with some type of dense material. Contrast materials are substances that are used to fill certain organs to make them more easily visible. These contrast materials contain agents such as barium or iodine that appear very dense on X-rays because they absorb or block more of the X-rays as these pass through the organ. Contrast materials can be introduced into the body, depending on the type, by mouth, by the rectum, or by injection into a vein through a catheter or indwelling tube. Contrast materials are usually harmless to patients, although occasionally a patient can have an allergic reaction to some types of contrast. If your child has unusual allergies or significant kidney problems that affect function, it is important for you to discuss these issues with the radiologist before the study is performed to be sure that pursuing the study is the right thing to do.
Fluoroscopic examinations use a combination of viewing the organs in motion on a computer screen and capturing still pictures of what is occurring during the procedure. Video recording is often used to save the real-time action of the examination for a certain period of time. The still pictures are saved for a much longer time on film or in a digital picture archiving system (PACS) stored in a computer system network. The still images can be burned on a CD so that the examinations can be viewed by other physicians, if necessary. Fluoroscopy is also used by interventional radiologists to visualize catheters and instruments during the course of procedures (see the Image Gently resources on Pediatric Interventional Radiology).
The gastrointestinal tract (esophagus [throat], stomach, small and large intestines) and the urinary tract (bladder, ureters, urethra) are the most common organs and structures to be examined by fluoroscopy in children. Some examinations require that the child not be fed for a period of time before the examination, so that the ingested food does not interfere with the radiologist’s ability to see the details of the organ. Studies that involve filling the rectum or bladder with contrast will require the placement of a small catheter or tube within the rectum or bladder to introduce the contrast material. Such catheters are safe and are generally placed with a minimum of discomfort for the child. Sedation can be used for some procedures but is rarely necessary. Examinations that evaluate the blood vessels are called “angiography” and require that contrast material is directly injected through a needle or intravenous catheter into the blood vessels; these typically are studies performed under Interventional procedures (see the Image Gently resources on Pediatric Interventional Radiology). The dynamics of the respiratory tract (lungs, vocal cords, trachea, diaphragm) are sometimes evaluated by fluoroscopy, and contrast materials are usually not necessary for these procedures. Pediatric specialists who are not radiologists, such as cardiologists, urologists, or gastroenterologists also use fluoroscopy to guide some of their procedures.
How much radiation is used in fluoroscopy examinations?
We are all exposed to small amounts of radiation daily from soil, rocks, building materials, air, water, and cosmic radiation. This naturally occurring radiation is called natural background radiation, and the amount that we receive depends on where we live. For example, people living in high altitude areas, such as Denver, are exposed to more cosmic radiation than people who live at sea level. Radiation measurements are used to estimate the amount of radiation deposited in the whole body or to an individual organ. The deposited energy represents the patient’s radiation dose. Because every patient is different in size and shape, different X-ray settings are used to accommodate these differences, resulting in a unique radiation dose for each patient and procedure. Comparing estimated doses for different exams is confusing. One way of looking at doses from X-ray examinations is to compare effective radiation dose estimates from different sources using the same units (millisieverts or mSv).
Radiation doses from fluoroscopic procedures vary, depending on the type of examination, the complexity of your child’s anatomy and medical condition, and your child’s size and shape. The chart below shows estimated radiation doses for various fluoroscopic procedures compared to background and to non-medical radiation exposures. These are only estimated doses, and the dose for your child may be higher or lower.
|Non-Medical Radiation Source
|| Radiation Dose Estimate
||Equivalent Amount Background Radiation
|Natural background radiation = 3mSv/yr 3 mSv 1 year
|| 3 mSv
|| 1 year
|| 0.04 mSv
|| 4 days
|Medical Radiation Source
|| Radiation Dose Estimate
|| Equivalent Amount Background Radiation
| 0.01 -0.05 -mSv
|| 1-5 days
Urinary tract fluoroscopy (VCUG)
| average 0.2 mSv
|| 20 days
How can we minimize radiation risk to my child?
There are many ways to ensure that your child is exposed to the smallest amount of radiation possible during fluoroscopy. Newer types of fluoroscopic equipment are designed to deliver the x-rays in short pulses (“pulsed fluoroscopy”) rather than in a continuous stream, which lowers the amount of radiation exposure. Shielding portions of the body with lead shields can sometimes be used, if the shields do not obscure the organs that are being examined. The Image Gently Alliance is promoting the following techniques for medical imaging examinations performed on children:
- Perform imaging examinations when there is a medical benefit.
- Use the most appropriate imaging techniques, matched to the size of the child and study indication
- Use alternative imaging methods (such as ultrasound or MRI) when possible
If my child’s doctor requests a fluoroscopic procedure, should I allow it?
In the overwhelming majority of cases, the benefits of using fluoroscopy to help make diagnoses and manage the health of children far outweigh the potential risk associated with radiation exposure. Fluoroscopy is sometimes the only non-invasive way to make a diagnosis or monitor treatment, and the examinations can solve problems faster and with less pain than other procedures. It is important to remember that if your child requires a fluoroscopic procedure, you can discuss with your physician, especially to understand the necessity and benefit of the examination. Radiologists are knowledgeable about the examination, especially ways to use only the necessary amounts of radiation in children during medical procedures; you should feel free to also ask the radiologist about techniques used to keep radiation doses as low as possible in children.
Ultrasound and MRI are imaging techniques that do not use ionizing radiation, but these methods cannot be used for all medical problems. When your child is scheduled for a fluoroscopic procedure, you may want to ask your physician or the radiologist if there are any other types of examinations that can be used to obtain the information needed.
How can I be sure that my hospital or imaging center is using appropriate radiation techniques for children?
The best way to ensure that the facility performing fluoroscopy on your child is using dose reduction techniques is to ask. It is reasonable and within your rights to ask your imaging facility about the steps that they have taken to make sure that radiation exposure to your child is as low as reasonably achievable. Your radiologist or imaging provider should be able to provide you with information about the examination that your child is undergoing and about how they reduce radiation doses.
If I still have concerns regarding radiation exposure to my child during fluoroscopy, to whom should I address my concerns?
You should first discuss your concerns with the physician who is requesting the examination. Medical professionals must consider the risks and benefits to your child in every test of procedure to which the child is referred. Your pediatric doctor and your radiologist can work together to make decisions about the best examination for your child. If your primary physician cannot answer your questions, your radiologist can provide more in-depth information about fluoroscopy. The information contained in this publication should not be used as a substitute for the medical care and advice of your doctors.
Image Gently is the educational and awareness campaign created by the Image Gently Alliance, formed in July 2007. It is a coalition of health care organizations dedicated to providing safe, high quality pediatric imaging nationwide. The Society for Pediatric Radiology, American Society of Radiologic Technologists, American Association of Physicists in Medicine, American College of Radiology, and over 100 other North American and international medical societies are members of this coalition, representing more than 1,000,000 health care professionals in radiology, general and subspecialty pediatrics, medical physics, and radiation safety around the world. More information can be found at www.imagegently.org, www.imagegentlyparents.org, and www.imagegentlyproviders.org.
Susan John, MD