A CT (computed tomography) scanner is a special machine that uses X-rays. Instead of sending individual X-rays through the body with a regular X-ray, multiple X-rays are sent simultaneously from different angles.
How does a CT scanner work?
Once they pass through the body, the X-ray beams are detected, and their strength is measured.
Bundles that pass through lower density tissues, such as the lungs, will be stronger, and bundles that pass through higher density tissues, such as bone, will be weaker.
The computer, using this information, calculates the relative density of the examined tissue. Each series of measurements with a scanner is a cross-section through the body.
The computer processes the results, displaying them as two-dimensional images on a monitor. The CT scanning technique was discovered by a British scientist Sir Godfrey Hounsfield, who received the Nobel Prize for this discovery.
What is a CT scan used for?
A CT scan gives more data than a plain X-ray. Doctors can reconstruct the information obtained from the two-dimensional computer image to obtain a three-dimensional image in some modern CT scanners. This can provide a virtual image that shows what the surgeon will see during the operation.
A CT scan allows doctors to see the body’s inside without surgery or awkward examinations. CT scanning has also proven invaluable in detecting and localizing tumors and in radiation planning (radiotherapy).
What is the use of a CT scanner?
A CT scanner was originally designed to scan the brain. It is now significantly improved and is used to capture any part of the body.
It is handy for detecting cerebral hemorrhages, aneurysms (when the artery wall bulges), brain tumors, and brain damage. It also detects tumors and abscesses in the body and is used to assess the type of lung disease.
It is also used to examine internal injuries such as a ruptured kidney, spleen, liver, or bone injuries, especially of the spine. CT scanning is also used in conducting biopsies and other procedures.
How do you prepare for a CT scan?
If, for example, the abdomen is imaged, the patient is suggested not to eat for six hours before the examination. He will be given to drink the contrast agent gastrografin 45 minutes before the shoot. This facilitates the visibility of the bowel.
Sometimes liquid contrast is injected through a vein during imaging. It also makes it easier to see organs, blood vessels, or tumors. Initiating contrast through a vein can be a little uncomfortable. Some people feel warmth in hand.
How is a CT scan performed?
The scanner looks like a big donut. During the scan, the patient lies on the bed, with the body part being examined in a circular tunnel. The bed is slowly moved back and forth to scan the body even though it does not touch the patient. The search length depends on the required number of images and the angles from which it is taken.
Can CT imaging hurt?
Although some people are uncomfortable lying in a tunnel, the search itself is not painful. Because there is little space inside the tunnel, people who have claustrophobia sometimes have trouble filming.
Tell your doctor and technician that this may be a problem. Some people may find it tense to hum the machine while filming.
Is CT imaging dangerous?
X-rays are much stronger in CT scans than in regular X-rays, so doctors do not recommend CT without a valid medical reason. Some patients may have side effects such as allergic reactions to contrast.
In sporadic cases, this contrast can damage already weakened kidneys. It is important to tell your doctor or technician if you have any allergy, asthma, or kidney problems, especially if you are receiving contrast.
How is a CT scan read?
A CT scan can give the doctor a much clearer picture of the inside of the body than a plain x-ray. For example, different tissue types such as bone, muscle, or adipose tissue are easily seen on a CT scan. On examination of the abdomen, the image shows various organs such as the pancreas, spleen, and liver.
When the brain needs to be examined, the areas filled with cerebrospinal fluid – the ventricles – are also clearly visible. CT can also detect minimal shadows on the lungs, and studies are now being done on its use as a screening test for lung cancer.