Imaging tests for children and teens

Imaging or radiology tests pass different forms of energy (X-rays, sound waves, radioactive particles, or magnetic fields) through the body, creating pictures of the chest, abdomen, head, neck, and other parts of the body. 

Imaging tests are generally used to detect signs of disease or to check whether cancer (tumors or masses of cells) has spread to areas such as the lymph nodes, chest, or lungs. Your child’s doctor may order an imaging test "with contrast," which makes it easier to see certain organs and tissues in the body. This means that before the test, the technician injects a contrast dye into one of your child’s veins or a port or asks them to drink a liquid containing the dye. If they’ve had a reaction to contrast dye or iodine in the past, tell the doctor or the technician. 

The doctor will give you and your child specific pretest instructions. It is important that your child's doctor knows if they may be pregnant, because many imaging tests use small amounts of radiation. 

Chest X-rays  

A chest X-ray produces images of the chest, lungs, heart, large arteries, ribs and diaphragm. Doctors use chest X-rays to detect signs of disease, including infection or tumors. An X-ray that shows an abnormal fluid collection can be a sign of infection, such as pneumonia or tuberculosis, or a tumor. A chest X-ray can also show evidence of enlarged lymph nodes or signs of internal injury.

How is a chest X-ray done? 

Your child will be asked to wear a gown during the procedure and to remove all jewelry. A technician will position them in front of the X-ray machine. Your child must hold their breath for a few seconds while the technician takes the X-ray; they will explain in detail what your child needs to do. Two images are usually taken, one from the back of the chest and another from the side. 

View the interactive 3D model to help you visualize and better understand the procedure. Click or tap the "Interact in 3D" button to begin. 

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Computerized tomography (CT) scans 

A computerized tomography (CT) scan shows a cross-section of the body using multiple images. CT scans are different than standard X-rays because they create a series of pictures taken from different angles and produce much clearer images. A CT scan help detect cancers in the liver, pancreas, lungs, bones, and spleen. The noninvasive test is also used to monitor a tumor's response to therapy or detect a return of cancer after treatment.

How is a CT scan done?  

If your child’s abdominal area is to be scanned, their doctor may prescribe laxatives, enemas, or suppositories or a temporary change in diet before the scan to cleanse the bowel. In some cases, your child may be asked not to eat or drink for several hours before the exam. 

If your child is anxious about being strapped down or confined in a small space, tell their doctor or the technician. Having the scan done in an open CT scan machine may be an option for your child. Some patients are given a mild sedative before the test to help them relax. Before the exam, contrast dye, if needed, is usually injected into a vein in the hand or arm. 

A CT scan normally takes between 10 and 30 minutes. Your child will be asked to wear a gown during the procedure and to remove any jewelry or metal objects. The technician will position your child on the CT scan exam table, usually having them lie flat on your back. The table is connected to a scanner with a round, doughnut-shaped hole in the middle. To determine the correct starting position, the table moves through the scanner quickly. When the actual scan begins, the machine rotates around the patient, taking a series of images. It's important that your child remains still during the exam. The technician may use pillows or straps to help them stay still. Your child may also be asked to hold and release their breath during the scan. 

View the interactive 3D model to help you visualize and better understand the procedure. Click or tap the "Interact in 3D" button to begin.

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Fluorodeoxyglucose with positron emission tomography (FDG-PET) scan 

Fluorodeoxyglucose with positron emission tomography (FDG-PET) is an effective tool for detecting lymphoma and other cancers. The test uses a radioactive glucose (sugar) molecule, called FDG, to produce images that show the tissues' metabolism (function). Because tumor cells require more glucose than normal cells to survive and multiply, doctors can identify cells as cancerous when they consume significantly large amounts of glucose. Tumors as small as one centimeter can be detected during FDG-PET. The test also provides a sensitive and relatively rapid assessment of a patient’s response to therapy.

How is a FDG-PET Scan done?  

If your child is anxious about being strapped down or confined in a small space, tell their doctor or the technician. Having the scan done in an open CT scan machine may be an option for your child. Some patients are given a mild sedative before the test to help them relax. Patients usually cannot eat before the test to ensure their blood sugar level isn't high. 

Before the PET scan, the technician injects your child with FDG containing a radioactive tracer. It takes 30 to 60 minutes for the radioactive glucose to travel through the body and be absorbed by the organ or tissue being studied. Your child may feel a cold sensation move up their arm when the radioactive tracer is injected, but there are generally no side effects. The exposure to radiation is minimal. 

The procedure is painless and takes about 45 minutes. Your child may be asked to remove any jewelry or metal objects and wear a gown during the scan, or they may be allowed to remain in loose-fitting clothing as long as it has no zippers or metal accessories. The technician positions your child on the PET exam table, which slides into a large scanner with a round, doughnut-shaped hole in the middle. It's important that your child stay still during the exam.

Magnetic resonance imaging (MRI) 

Magnetic resonance imaging (MRI) is a noninvasive procedure that provides detailed pictures of internal organs, soft tissues, blood vessels, and bones. MR images are made with a large magnet and radio waves and can show signs of disease (tumors or masses of cells). An MRI can also detect bone changes—common in some forms of cancer such as myeloma—earlier than conventional X-ray studies can.

How is an MRI done?  

If your child is anxious about being strapped down or confined in a small space, tell their doctor or the technician. Some patients are given a mild sedative before the test to help them relax. Having the test with an open MRI machine may be another option. Before the exam, contrast dye, if needed, is usually injected into a vein in your child’s hand or arm. 

The procedure is painless and normally takes between 15 and 45 minutes, depending on the area being scanned. Your child will be asked to remove any jewelry or metal objects and wear a gown during the procedure, or they may be allowed to remain in loose-fitting clothing as long as it has no zippers or metal accessories. 

The technician positions your child on the MRI exam table, which slides into a machine shaped like a tunnel. It's important that they remain still during the exam. As multiple images are taken, your child will hear a series of loud knocking sounds. 

View the interactive 3D model to help you visualize and better understand the procedure. Click or tap the "Interact in 3D" button to begin.

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Positron emission tomography-computed tomography (PET-CT) scans 

This procedure combines the techniques of both PET and CT imaging. A PET-CT scan reveals information about both the structure and function of cells and tissues in the body during a single imaging session. It provides a more detailed picture of where the cancer is located in the body than either test does by itself. 

How is a PET-CT done? 

Both PET and CT imaging tests are done at the same time and in the same machine. 

Ultrasound 

An ultrasound, also called a sonography, uses high-frequency sound waves to create pictures of internal organs, tissue, and blood flow. Unlike other X-rays and CT scans, ultrasound doesn't use radiation. Doctors use ultrasound to: 

• Detect cysts, tumors, or organ damage following illness and other medical problems
• Evaluate symptoms like pain, swelling, and infection 

This noninvasive procedure is commonly used by obstetricians to view a developing baby in the womb or by cardiologists (heart specialists) to evaluate a pumping heart's function.

How is an ultrasound done?  

Follow the doctor's instructions to prepare for an ultrasound. For some scans, your child’s doctor may tell them not to eat or drink for up to 12 hours before the test. For others, your child may be told to drink up to eight glasses of water one to two hours before the exam and not to urinate so their bladder is full for the scan. 

When your child undergoes the ultrasound, the technician applies a lubricant to the area of their body being examined. This helps the technician slide the handheld instrument across their skin, transmitting sound waves to create pictures on a screen. The technician slides the device around the body area while viewing and capturing different images. 

View the interactive 3D model to help you visualize and better understand the procedure. Click or tap the "Interact in 3D" button to begin.