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CT Scanners

CT Scanners

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CT scanners are amazing machines that can create highly detailed and in-depth images of the human body. Unlike traditional X-rays, CT scanners can produce 3D images of your insides! This means doctors can see a lot more information get a better understanding of what's going on. Plus, CT scanners can show the contrast between soft tissues, something traditional X-rays can't do. So, next time you need to get an image of your insides, ask about CT scanners!

What is computed tomography (CT)?

CT scanners are a type of machine that lets doctors see inside your body without cutting you open. They're really helpful because they can show things that normal X-rays can't. With normal X-rays, bones can get in the way and hide important stuff. But with CT scanners, doctors can take lots of pictures from different angles to see everything. Different CT scanners can be used for different things, but they all have the same basic parts: a scanner, an X-ray machine, a computer, and a screen for the doctor to look at. The X-ray machine makes special rays that go through your body, and the computer puts all the pictures together to make one big, detailed image.

A CT scanner
A CT scanner

CT scan procedure

When doctors need to see inside your body, they may use a machine called a CT scanner. CT scanners take pictures from lots of different angles to make a 3D image. To do this, they use special X-rays that pass through your body and are detected on the other side There are two types of CT scanners: cone beam and fan beam. Cone beam CT scanners are newer and don't rotate around you as much. Fan beam CT scanners are older and more common. In this article, we'll focus on fan beam CT scanners, which use a fan-shaped beam of X-rays to create the image.

Diagram showing the mechanism of a fan-beam CT scanner
Diagram showing the mechanism of a fan-beam CT scanner

The above graphic shows how a CT scanner works to achieve scans from multiple angles. Let’s look at how a CT scanner works step by step.

When you get a CT scan, you lie down on a bed in the middle of the machine. The machine has an X-ray tube and detectors that rotate around you. The X-ray tube makes beams of X-rays that go through your body and are detected on the other side. The detectors record how much of the X-rays were absorbed by your body, which creates contrast in the image. The machine takes lots of pictures as it rotates around you, and a computer puts all the pictures together to make a detailed 3D image. This helps doctors see what's going on inside your body without cutting you open. The X-rays used in CT scans have an energy range of 20 to 150 kiloelectronvolts.

The average linear attenuation coefficient

The contrast of the CT scan image depends on how much of the X-ray beam is absorbed by your body. This absorption is related to something called the linear attenuation coefficient, which can be expressed mathematically. For example, muscle has a linear attenuation coefficient of 0.180m-1, while blood has a coefficient of 0.837 and bone has a coefficient of 0.619. This means that blood and muscle don't have much contrast, so doctors may use a contrast medium with iodine to help highlight blood vessels. There is another type of CT scanner called a ring scanner, which uses stationary detectors and a rotating X-ray tube to create the image.

Diagram showing the mechanism of a ring CT scanner
Diagram showing the mechanism of a ring CT scanner

Advantages:

  1. CT scanners are very good at showing small details with density differences of less than one percent.
  2. They provide detailed images that can be used to diagnose a wide range of medical conditions.
  3. They are quick and non-invasive, making them a popular choice for medical imaging.
  4. CT scans can be performed on patients of all ages.

Disadvantages:

  1. CT scans use X-rays, which can be harmful if used excessively.
  2. They are more expensive than some other medical imaging techniques.
  3. Patients may experience discomfort or anxiety during the procedure.
  4. CT scans can expose patients to a higher radiation dose than other imaging techniques.
  5. Some patients may be allergic to the contrast agent used in CT scans.

Overall, while CT scanners have many advantages, it's important to weigh the potential risks and benefits before deciding to use them for medical imaging. Doctors should consider the patient's individual needs and medical history before recommending a CT scan.

Applications of CT scanners

CT scanners are a valuable tool in medical physics and are used for various purposes, including locating infections, diagnosing vascular diseases and injuries to bones and spine, determining internal injuries caused by trauma or accidents, locating different types of cancer, and assisting in biopsies. CT scans use X-rays to create detailed, three-dimensional images of the body, and there are two main types of CT scanners: cone beam and fan beam. While CT scanners have many advantages, including their ability to produce highly detailed images, they also have potential disadvantages, such as exposure to radiation and discomfort or anxiety during the procedure. Overall, CT scanners are an important tool for medical professionals in diagnosing and treating a variety of conditions.

CT Scanners

What are CT scanners used for?

CT scanners are used for a variety of purposes in medical physics including diagnosing problems in the spine, determining and locating different types of cancer, determining internal injuries caused by trauma or accidents, etc.

What is a CT scanner and how does it work?

Computed tomography (CT) (also known as computerised tomography) was the first in its field as a non-invasive radiological method that allows medical professionals to view the inside of the whole human body without needing an adjoining structure. To achieve different goals, manufacturers modify the structure of CT scanners. However, all CT scanners are, in general, similar to each other and consist of a scanning gantry, an X-Ray tube, a computer system, and a viewing console for the radiologist.

What type of radiation does a CT scanner use?

CT scanners use X-ray beams to create highly detailed images of the interior of the human body.

Who invented CT scanners?

Godfrey Newbold Hounsfield created the first commercially available CT scanner.

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