What is a CT scan?
Computed tomography – CT or CAT scan – is an advanced diagnostic medical imaging that uses special X-ray equipment to help detect a variety of diseases and conditions by producing multiple images of the inside of the body. In case of emergency, it can detect internal injuries quickly enough to help save lives.
The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. We are proud to have one of the Hungary’s fastest CT scanner at our Hospital on site, providing excellent image quality for clear visualization of almost all parts of the body.
Why is a CT scan needed?
Common disorders a CT scan may find include:
- Head: blood clots, skull fractures, tumors, and infections
- Spine: vertebral fractures and herniated intervertebral disks
- Chest: heart abnormalities, lung abnormalities and infections
- Abdomen: tumors, infections, abnormal anatomy, appendicitis and cysts
Radiologists often use the examination to:
- Quickly identify injuries to the lungs, heart and vessels, liver, spleen, kidneys, bowel or other internal organs in cases of trauma.
- Guide biopsies and other procedures such as abscess drainages and minimally invasive tumor treatments.
- Plan for and assess the results of surgery, such as organ transplants or gastric bypass.
- Stage, plan and properly administer radiation treatments for tumors as well as monitor response to chemotherapy.
- Measure bone mineral density for the detection of osteoporosis.
What happens during a CT scan?
Our scanner technologist begins by positioning you on the examination table, usually lying flat on your back. Straps and pillows may be used to help you maintain the correct position and to help you remain still during the exam. Any motion, whether breathing or body movements can cause blurring of the images and degrade the quality of the examination the same way that it affects photographs.
Depending on the type of CT scan, the machine may make several passes. When the examination is completed, you will be asked to wait until the operator verifies that the images are of high quality enough for accurate interpretation.
If contrast material is used, depending on the type of exam, it will be swallowed, injected through an intravenous line or, rarely, administered by enema.
The examination is usually completed within a few minutes. The portion requiring intravenous contrast injection usually lasts only 10 to 30 seconds.
How does a CT scan work?
Specifically, computed tomography scan is a non-invasive clinical diagnostic tool that allows for three dimensional visual reconstruction and segmentation of tissues of interest. High resolution systems can be used to perform non-destructive 3D imaging of a variety of tissue types and organ systems, such as: the gastrointestinal tract, cardiovascular system, renal tract, liver, lungs, bone, cartilage, tumorous tissue, etc.
A CT image is obtained by rotating an X-ray source around an object, with a detector positioned directly opposite the radiation source. Alternatively, in many preclinical CT scanners the object sometimes is rotated around its own axis. Generally, X-ray images are taken at small angular increments during rotation around the object over 360°. A series of attenuation profiles or projections is thus obtained. The projections are then processed mathematically to create a 3D rendition of the scanned object.
What are the benefits and risks of CT scan?
Benefits of CT scans
Benefits of computed tomography include:
- determining when surgeries are necessary
- reducing the need for exploratory surgeries
- improving cancer diagnosis and treatment
- reducing the length of hospitalizations
- guiding treatment of common conditions such as injury, cardiac disease and stroke
- improving patient placement into appropriate areas of care, such as intensive care units
CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancer, cardiovascular disease, infectious disease, appendicitis, trauma and musculoskeletal disorders.
Risks of CT scans
- Radiation exposure
During a CT scan, you’re briefly exposed to ionizing radiation. The amount of radiation is greater than you would get during a simple X-ray because the CT scan gathers more detailed information. CT scans have not been shown to cause long-term harm, although there may be a very small potential to increase your risk of cancer.
CT scans have many benefits that outweigh this small potential risk. Doctors use the lowest dose of radiation possible to obtain the needed medical information. Also, at Medicover Hospital we use the newest and fastest machines that require less radiation than was previously used.
- If you are pregnant
Typically not recommended for pregnant women unless medically necessary because of potential risk to the baby. Women should let their doctor and scan technician know if there is any chance they are pregnant. In this case another type of exam may be recommended, such as ultrasound or MRI, to avoid exposing your baby to radiation.
- Contrast dye
In certain cases, your doctor may recommend you receive a special dye called a contrast material through a vein in your arm before your scan. Contrast agents are used to improve pictures of the inside of the body by temporarily changing the way X-rays interact with area being examined. Although rare, the contrast material can cause mild allergic reactions, resulting in a rash or itchiness.
How should I prepare for CT scan?
It is recommended to wear comfortable, loose-fitting clothing to your CT scan and you may be given a gown to wear during the examination.
You should leave at home or remove prior to your exam all metal objects, like jewelry, eyeglasses, dentures and hairpins, that may affect the images. You may also be asked to remove hearing aids, removable dental work and any piercings, if possible. For an MRI of the abdomen, pelvis, lungs and chest, you may be asked to not eat or drink for several hours before the test.
Women should always inform their physician and the operator if there is any possibility that they may be pregnant.
What are the limitations of CT scanning?
A conventional CT scan will visualize approximately nine out of ten pancreatic cancers and has a primary limitation regarding its approximately 1 centimeter resolution. But at Medicover Hospital we use the most cutting-edge Siemens SOMATOM Scope scanner for the outmost imaging quality, better resolution than in case of older CT scanners, fast and reliable scanning.
The optimal scanning time lasts for about 20 seconds. If the scanning proceeds slowly, as with conventional CT, the dye can sometimes wear off before the scanning is complete.