CT Scan in Children
What is CT Scanning?
CT scanning also known as CT scan is a noninvasive, painless radiological test to evaluate many disorders of the brain. CT scan uses special x-ray equipment to produce multiple cross sectional images of the body- which are then analyzed by a computer and converted into a 3 dimensional picture. The CT scan is many times more sensitive then the plain x ray in imaging the body.
In children as well as adults, CT scanning is the preferred to the customary x-ray exam. It may be performed in newborns and infants as well as older children and adolescents. CT scans may be done with or without contrast material that is taken by mouth or injected into a vein. These contrast-enhanced exams often depict a particular organ, tissue, or blood vessel more clearly.
What conditions can CT scan be used for in children?
CT scan may be recommended in order to detect a wide range of abnormalities or diseases in a child. Ct scan is excellent at evaluating most disorders in a child and the common disorders are:
- determine disorders of the chest and lungs (infections, congenital, masses)
- determine causes of abdominal pain, swelling, infection
- determine causes of headaches, brain cancers
- determine causes brain infections and swelling
- identify birth defects anywhere in the body
- identify cancers in most part of the body
- help with CT guided biopsy
- determine causes of seizures
- evaluate child after trauma
- determine bone fractures and spinal cord disorders
- determine disorders of kidney, pancreas, liver, spleen, small bowel, duodenum
What preparations are required for a CT Head scan?
One should not eat 2-3 hrs prior to the procedure. When arriving to the radiology suite, one should wear loose-fitting clothing to your exam or a gown can be provided.
All metal objects including jewelry, eyeglasses, dentures and hairpins can interfere with CT imaging an should be removed or left home prior to the CT scan.
Anyone with allergies/asthma should inform the technologist of this. Individuals with allergies/asthma are required to take some medications at least 24 hrs prior to the procedure.
Individuals with kidney/diabetes problems may be admitted the night before and hydrated with fluids.
Women should always inform their physician or technologist if there is any possibility that they are pregnant. Pregnancy is usually a contraindication to a CT scan, unless the benefits of the test override the risks.
What does the CT scan equipment look like?
The CT scanner is a large machine with tunnel housing in the center. A moveable examination table slides into and out of this tunnel. In the center of the machine, the x-ray tube and electronic x-ray detectors are located opposite each other- and rotate around the patient. The images generated are processed by a computer.
Recent advances in scanning technology allow new CT scanners to obtain multiple images in a single rotation. These scanners, called "multi slice CT" or "multidetector CT," allow thinner slices to be obtained in a shorter period of time, resulting in more detail and better resolution. These fast scanners are beneficial for critically ill patients and the elderly.
How is the CT scan performed?
You will be asked to lie down on a flat table which is mobile. An IV is usually started when contrast material is used in the study. After this, the table moves into the tunnel where the actual imaging is done. During the procedure, you may be asked to hold your breath for a few seconds to prevent any motion artifacts. Unfortunately, no one else is allowed in the CT scan room because of radiation exposure but you will be watched through a window by the technologist. The technologist will also speak to you via a microphone. Once the imaging has been completed, you can go home. The imaging takes about 15-20 minutes.
How does one feel during the procedure?
CT scan is a painless procedure. Today's fast speed scanners can complete the imaging in less than 5-10 minutes, thus reducing the time needed to lay flat and still.
The only discomfort of CT scanning is the lying down flat for a few minutes. This may be of no consequence to most individuals but can be discomforting to those with neck and back problems. In addition, the CT scan does tend to cause a claustrophobic feeling because of the closed space enclosure.
When contrast is used, the individual may feel warm all over the body during the injection. This is a transient painless feeling. Others may complain of a metallic taste in the mouth. The rare individual may develop an allergy which may be associated with hives and pruritis (itching).
When the contrast material is swallowed, it does have an unpleasant taste but tolerable. Most individuals complain of bloating after swallowing the dye- symptoms which rapidly subside.
General CT scan precautions in children:
When a child is having a CT scan, one of the parents or a nurse may be allowed into the room but is required to wear a lead apron to prevent radiation exposure.
After the CT scan, one can resume all normal activities. If contrast was administered, one is encouraged to drink lots of fluids.
Your child may eat and drink as usual and take needed medication as long as no contrast is to be given and no sedative (calming medication) or anesthesia is planned. If anesthesia is planned, your child probably will not be allowed to eat for three to six hours, depending on age, before scanning. In general, children who recently had a respiratory tract infection are not sedated or anaesthetized. Unless a CT is required emergently, a sick child can not have a CT scan.
The computer that processes the CT images is in a different room. The CT staff will observe the child constantly either visually or via closed-circuit television. Speakers and microphones inside the scanner will permit the technologist to both hear and speak to your child as scanning proceeds. Some units have a call bell within reach so that you or your child can inform the technologist if any problems arise.
Who interprets the results and how do I get them?
The Scans are always read by a radiologist. If prior arrangements have been made with the radiologist, then the results can be available 30 mins after the CT is done.
What are the advantages vs disadvantages of a CT scan in children?
- CT scan is a painless non invasive procedure with good sensitivity to detect most disorders in a child
- CT scan is far superior to an MRI when evaluating skull fractures
- Ct scan can provide detailed images of the entire abdomen and pelvis
- CT is excellent for individuals involved in head trauma
- CT can rapidly identify most congenital disorders
- CT is excellent in trauma patients
- CT scan is much cheaper than an MRI an equally as fast
- The newer generation of CT scans can combine angiography and assess the blood supply to any organ
- The motion artifacts are less of a problem with a CT scan compared to an MRI
- CT scan can be performed in patients with implanted medical devices
- CT scan provides dynamic imaging and thus allows for needle biopsies to be performed simultaneously
- unlike MRI, CT scan is associated with a radiation (this is about the same radiation exposure that a normal individual would get in about 12 months)
- CT scan should never be done in a pregnant female because of the exposure of radiation risk to the fetus
- The dye used in a CT is iodine based and is often a cause of allergy. The dye can also lead to kidney failure in individuals with diabetes
- Unlike adults, CT scan should not be repeated in children because of the repeat radiation exposure
- CT is not very good at identifying pathology of the soft tissues
- CT is not good at identifying areas of inflammation or infection of the brain compared to MRI
- CT scan in children often requires sedation
- Ct scan in children requires patience and constant monitoring
What are the limitations of CT Scanning in children?
An obese patient may not be able to fit in the machine.
For those who have partial renal failure, injection of contrast may not be possible because of the risk of inducing complete renal failure.
Many children are frightened by large machines and the general hospital atmosphere; the presence of a parent, close relative, or friend is usually required for reassurance.
Some imaging facilities may use general anesthesia in young children who are unable to hold still. In this case you will be permitted to stay until your child has fallen asleep. Thus after a CT scan, you may have to wait until the child is awake and fully alert.
There always a risk of complications from general anesthesia or sedation. Every measure will be taken to protect the welfare of your child, including close monitoring.
Other imaging methods such as ultrasound or magnetic resonance (MR) imaging can provide pictures of certain areas of the body that sometimes are as good as or better than those obtained by CT scanning. The ultimate test will be decided by your physician.
Your child may require a needle-stick in order to inject contrast material into a vein and thus may cry or become afraid.
Because children generally do not lie still for long periods, motion can affect the quality of a CT scan.
CT scans do require radiation, although the lowest dose needed to obtain high-quality images will be used.
What is the cost of a CT scan?
The average cost of a CT scan of the head is about $200-$400.
By ScanDirectory.com Staff
Updated: July 20, 2007