CT scan (CAT scan) with sedation or anesthesia

What is a CT scanner?

The CT scanner itself is a large machine with a hole in the center, which looks like a giant doughnut. Your child will lie still on a table that slides into and out of the opening while the machine takes pictures of the part of your child's body that is being investigated. Even though the machine is large and makes humming noises, it will not touch your child during the scan.

How does a CT scanner work?

An x-ray tube on a rotating gantry within the "doughnut" emits controlled, narrow beams of x-ray radiation, which pass through the body and get picked up by an array of electronic detectors. This produces many pictures in thin two-dimensional "slices" of the area under study. The slices are then assembled by a dedicated computer, which can compile them into detailed three-dimensional images that can be studied from all angles.

Why might a CT scan be needed?

In children, CT is often used to investigate head injuries or acute neurological symptoms, evaluate chronic sinus symptoms or hearing loss, diagnose appendicitis, evaluate masses, detect fractures or to help determine why a child has trouble breathing. Because it provides detailed views of many types of tissues, it is an excellent way to rule out disease and facilitate treatment.

Your child's doctor may request a CT scan to obtain specific diagnostic information that is not provided by or is complementary to information from other imaging technologies such as conventional x-rays, ultrasound, nuclear medicine or magnetic resonance imaging (MRI).

In emergencies, a CT scan can quickly reveal internal injuries and bleeding, providing important information to the medical team that may prove life-saving. 

How should I prepare my child for the CT scan?

The most important thing is to tell your child in simple terms why the test is necessary. You can explain that the CT won't hurt and that the machine does not touch the body. However, there will likely be some discomfort when the nurse places the IV line needed to administer the sedation. It is important to carefully follow all the instructions we give you in advance so that the exam does not need to be rescheduled.

If your child will be receiving sedation:

• Do not give your child any solid foods or full liquids in the four hours before the test. Examples of solid foods are cereal, bread and candy. Examples of full liquids are milk, formula and orange juice.
• You may give your child clear liquids up to two hours before the time of the CT. Examples of clear liquids are water, tea without milk, broth and breast milk.
• If you have any questions about sedation, please call 617-355-6308 and ask to speak to the Radiology nurse

If your child will be receiving anesthesia:

The nurse will call you with instructions prior to the exam.

What should I expect when I bring my child to the hospital?

 The day of your child's exam, come to the Radiology suite on the second floor of the main Boston hospital or on the first floor at our Waltham facility and check in at the front desk.

• After you have checked in, a technologist will greet you and explain the test in detail, answering any questions you or your child might have.
• A nurse, a nurse practitioner, a sedation-trained pediatrician, or an anesthesiologist will perform a physical examination and take your child's medical history. You will be allowed to stay with your child until he or she is taken into the CT room for a general anesthetic or sedation.

 What happens during the CT scan?

The technologist positions and secures your child on the movable bed that slides into and out of the CT scanner. The technologist then performs the exam according to the imaging protocol specified by the radiologist. The technologist is in direct contact with the radiologist at all times.

What happens after the procedure?

• The radiologist reviews the pictures.
• Your child will be moved to a recovery area to be monitored.
• When your child is ready to go home, the recovery nurse will remove the IV and monitoring equipment.
• You will be given discharge instructions with contact information in case you have any questions or problems after leaving the hospital.
• Your child may be sleepy, so it is important to help him to prevent falling.

A wheelchair with a safety strap will be used to transport your child to your car. You may not walk or take public transportation after this appointment. A recovery room nurse will call the next morning to make sure that your child has fully recovered from the sedation.

How will I learn the results of my child's CT scan?

After the pediatric radiologist or pediatric neuroradiologist interprets the images, r she will make a written report to your child's doctor, who can then tell you the results. Results are typically reported within 24 hours; in urgent cases, our radiologists communicate immediately with the referring physician.

What are the risks of CT scans?

CT scans involve ionizing radiation as is used in conventional x-rays. In certain clinical situations, the benefits of an accurate diagnosis outweigh the risk of exposure to radiation during the exam. We calibrate our x-ray-based equipment and adapt protocols to deliver doses appropriate to children. The narrow beams of radiation used in CT, as well as protective shielding that prevents unnecessary radiation to sensitive tissues, also help limit radiation dose.

Sometimes, it's possible to reach a diagnosis by using imaging technologies that don't involve radiation: ultrasound or magnetic resonance imaging (MRI), for example. When appropriate, our radiologists will advise referring physicians that this is the safest course of action.