A computed tomography scan, often referred to as a CT scan or CAT scan, is a tool that allows doctors to see the components of your body on the inside. This process is more advanced and detailed than an x-ray. It uses X-rays as well as a computer to create pictures of the organs, bones, and other tissues throughout the body.
While many people throw around the idea of a CT scan to diagnose, many do not understand what it does. Here are some frequently asked questions regarding CT scans and their part in the treatment of disease.
How Do CT Scans Work?
Unlike a conventional x-ray, which uses a tube that is fixed and only focuses on one part of the body, a CT scanner uses a motorized x-ray machine that moves around the opening of a donut-shaped structure which is called a gantry. While the CT scan is happening, the patient lies on a bed that slowly moves through the gantry while the x-ray tube rotates around the patient.
During this time, x-ray beams are shooting through the body. While x-rays use films, CT scanners use special detectors that work with the computer to create an image that is more detailed than the traditional x-ray machine.
A CT scan is unique in how it produces 2D images to layer over one another to create a more three-dimensional view of a particular area of the body. Any time the CT scanner makes a rotation, the CT computer creates a slice of an image, which is one layer of the section of the body. These layers vary in width depending on the part of the body being scanned and range between 1-10 millimeters.
After each slice is imaged and processed, the picture is stored and the electronic bed that the patient is on is moved forward slowly into the gantry. This image scanning and layering process is repeated until the desired section is completely imaged, and the desired level of detail is achieved through a specific number of slices.
When Does a Doctor Order a CT Scan?
While x-rays are typically used for bone breaks and fractures, a CT scan can be used for many more reasons. Because of this, a doctor might order a CT scan for a variety of reasons. Because of its detail, a CT scan is extremely useful in diagnosing a myriad of illnesses, injuries, diseases, and other ailments.
- While x-rays are used for bones, a CT scan can be used in combination with the x-ray results to diagnose bone injuries and diseases such as osteoporosis and bone cancer.
- CT scans are great for finding masses that are often a part of cancer and malignant tumors.
- CT scans can be used to find internal injuries, such as internal bruising or organ bleeds, after blunt force trauma and automobile accidents.
- They can be useful for finding tumors, excess fluid, or other abnormalities within the body.
- They can be used to check progress to determine if a treatment such as chemotherapy or physical therapy is working. In this period, it can be measured against previous CT scans and presented to the patient to show progress or regression.
How Long Does the CT Scan Process Take?
While an x-ray has a set amount of time that it takes to develop, the time it takes to get a CT scan varies based on the level of detail that is needed and what part of the body needs to be scanned. If oral contrast dye is needed for the procedure, it will take between 45-60 minutes for the dye to move through your digestive tract. However, there is not a set time for the actual scan.
If oral contrast is not required, the examination will take approximately 15 to 30 minutes. This approximation includes the time needed to prepare the IV as well as an interview. it is important to note that these times will fluctuate based on the needs of the patient, as well as what the doctor orders for the scan.
Do I Have to Prepare in Advance to Take a CT Scan?
In some situations, there will be additional preparation for a CT scan such as the needs of a contrast dye. If a contrast dye is needed, the patient will be asked and required to not eat or drink for three hours prior to the scan. Unless the patient is restricted further, the patient may drink clear liquids. While contrast dyes are used often, they are not required in all scans.
A contrast dye is typically used to highlight certain organs within the digestive system for diagnostic reasons. An example of this would be to highlight the colon to find abnormalities. Contrast dyes can be administered orally or even anally. This is with either a pill or an enema.
The patient will be required to bring their doctor’s order to the appointment if one was provided to them
The patient will also be required to remove any jewelry since it can interfere with the CT scan and ruin the results.
Get Your Questions Surrounding Your CT Scan Answered
A CT scan is great for a variety of uses in the medical field. From checking the potency and power of a particular therapy on a part of the body to diagnosing a variety of illnesses and diseases, a CT scan is a great resource for those in the medical field.
If you have more questions about your upcoming CT scan or need to talk with a physician about the potential benefits of a screening, contact the professionals at the North Texas Medical Center to learn more information.