Pediatric CT Scan
What is a CT scan?
Computed tomography (CT) (sometimes called "computerized tomography" or "computed axial tomography" (CAT)), is an X-ray exam that uses specialized equipment to produce cross-sectional images of the body. Each cross-section represents a “slice” of the part of the body being imaged. When viewed together these images provide a comprehensive view of the area imaged, with greater clarity and more detail than conventional X-ray images. Using special software doctors can generate three-dimensional images from the individual slices of a CT scan. Doctors use CT scans of internal organs, bones, soft tissue, and blood vessels to:
- Diagnose disease or trauma-related abnormalities
- Plan and guide interventional or therapeutic procedures
- Monitor the effectiveness of therapy for diseases like cancer
A CT imaging system includes a scanner shaped like a donut and a motorized table that slides in and out of the opening in the scanner. Your child will lie on the table and while he/she is inside the scanner, an X-ray source and a detector assembly opposite the source will rotate around the table. During a single rotation, which takes about a second, a fan-shaped beam of X-rays passes through a section of the child’s body and is registered by the detectors opposite. The scanner collects images from many different angles during a complete rotation; these are sent to a computer, which reconstructs all of the individual "snapshots" into one or multiple cross-sectional images (slices) of the internal organs and tissues. For some CT exams we will give your child a contrast agent intravenously or by mouth to make the organs and structures more visible in the images we create.
How should I help my child get ready for the test?
Some types of CT exam require specific preparations beforehand.
If your child is having a CT of the abdomen or pelvis with contrast, you will be instructed to come to the hospital approximately two hours in advance of your scan, and we will give him/her a drinkable contrast agent.
For some types of CT scans we will give a child the contrast agent intravenously; if your child will be getting intravenous contrast, he/she should not eat anything for two hours before the exam.
On the day of the test your child should wear comfortable clothes, and he/she may be asked to change into a gown when you arrive at the CT exam site.
What will happen during the test?
A CT exam is usually painless and quick. If your child’s doctor has requested that your child have a CT scan with intravenous contrast, we will first insert an IV, usually into his/her hand or arm. Your child may feel a warm, flushed sensation during the injection and may have a slight unpleasant taste in his/her mouth for a few minutes. Occasionally a child develops itching and hives from the contrast, which we can relieve with medication. Even more rarely a child becomes light-headed or has difficulty breathing; these may indicate a more severe allergic reaction, and you should notify the technologist or nurse immediately. If your child is being sedated for the exam we will also insert an IV.
We will then take you and your child to the CT exam room, and position him/her on the CT table, usually on his/her back. When the table slides into the scanner a red light may shine on your child’s body, which helps ensure that he/she is properly positioned. We use the most up-to-date CT scanners, which make only slight buzzing and clicking sounds as the scanner revolves around your child. The CT technologist will leave the room to perform the scan, but he/she will be able to see, hear, and speak with your child at all times.
The technologist will ask your child to hold very still, and may ask him/her to hold his breath a few times during the scan. Any type of movement during a CT scan will make the images look fuzzy, and may have to be repeated.
The scan will take between five to 15 minutes to complete.
What can I do to help my child feel comfortable during this test?
Young children sometimes find the CT scanner a bit frightening. You can remain with your child in the imaging area during the exam to offer comfort and reassurance and will be asked to wear a lead apron to protect you from unnecessary exposure to radiation. We can also arrange to have a child life specialist at your child's appointment to help your child better cope with the stress of the procedure.
Are there any risks?
CT exams use higher radiation doses than conventional radiography because the CT image is reconstructed from many individual X-ray projections. If the exam is medically necessary the risk is quite small compared to the benefit of an accurate diagnosis or intervention. Some children may have a mild reaction to the intravenous contrast agent, or dye.
After the test
After the exam your child can immediately resume his/her normal activities. If your child was sedated, though, you will be asked to wait in the imaging area after the exam until your child is reasonably alert.
A radiologist will analyze the CT images and will share the results with the doctor who requested the exam. Your child’s doctor will then discuss the results with you. In some cases the radiologist may discuss the results with you at the conclusion of the examination.