1. How does a CT scan work?
A narrow X-ray beam circles around a part of your body that has to be examined. Thus, a series of images of that part is captured in varied angles. Here the role of the computer is to use this information to create cross-sectional pictures. This 2D or two-dimensional scan shows a slice of that body part.
This entire process is done repeatedly to arrive at a number of slices. Now the computer stacks these scans on top of each other. This helps to get a detailed image of your bones, organs, or blood vessels.
2. How does this help a doctor?
This helps the doctor or surgeon to look at different sides of a tumor to decide on how to operate the patient, rendering a realistic view to the doctor and preparing him/her for the surgery.
X-ray and CT scan:
X-ray machines have a fixed tube to point X-rays on a single spot. When X-rays start to travel through your body, they are absorbed by tissues in different amounts. Tissues with higher density create a whiter image as compared to other tissues. This image is captured against the black background of the film.
X-rays are 2D images while CT scans are a bit different since they have a doughnut-shaped tube rotating around you in 360 degrees. Thus, the data that is produced through this process is used to capture 3D images of your body parts, bones, tissues, or organs.
3. Why does a doctor recommend a CT scan?
A doctor would need a CT scan for the following reasons:
- CT scans are required to detect joint and bone issues like tumors or bone fractures that are complex and need further examination.
- In case of an internal injury and bleeding after an accident, a CT scan is necessary.
- It helps in studying the progress of the cancer treatment and how a patient is responding to chemotherapy.
- Doctors can locate a blood clot, infection, tumor, or excess fluid.
- Health issues like heart disease, liver masses, lung nodules, cancer or emphysema, can be spotted by a CT scan, helping the doctor to see the changes as well.
- After studying the CT scan a doctor can guide the future course of treatment, and procedures like radiation therapy, biopsies, and surgeries.
4. CT scan reconstructs individual images:
While conducting a CT scan, X-rays are used but, different views of the images are captured and then fed into the computer. The word “tomography” from Computer Tomography is derived from a Greek word that means ‘slices’. The CT scan machine records slices of that part of the body, which the doctor wishes to examine. Then the computer assembles these slices to get a clear view of the inside part of your body. The doctor receives these images on a computer screen, a CD, an X-ray film, or a DVD.
5. CT scan won’t hurt:
You won’t experience any pain during the scan. You have to lie on an examination table that slides into the CT scan machine. Post that the machine will rotate around you and X rays are captured. Your body is not touched by the machine. All you have to do is stay still and hold your breath after intervals for short periods. It’s true that you will hear a whirring sound that is soft. Generally, you are alone in the exam room, but your voice is heard by the technician. This entire process takes 30 minutes.
6. Stay still during the scan:
Ensure that you stay still during the procedure because if you move the images will be blurred. Even your breathing affects the image. The technician will ask you to hold your breath so, follow the instructions.
A scan will take anywhere between a few minutes to an hour. You can talk to the radiologic technologist by using an intercom system during the procedure if you feel anxious or uncomfortable.
7. Why a contrast dye is required?
Sometimes, scans will require the use of a contrast agent.