What is the difference between a low-dose CT scan and a regular CT scan?

February 12, 2024 – 8 min read

Share this post:

You’ve heard the phrase, “moderation in all things.” Here’s another one, “sometimes less is better.” For certain people who would benefit from limited exposure to radiation, a low-dose CT (Computerized Tomography) scan can be a better choice than a regular CT scan.

Low-dose CT is a relatively new imaging scan that’s a great fit for some patients. Find out everything you need to know about low-dose CT scans, and learn who is a good candidate for low-dose CT, so you can make an informed decision.

What makes low-dose CT scans different?

A low-dose CT scan is non-invasive and takes little time to perform. This low-dose screening test works just like a regular CT scan but with a significantly lower radiation dose, which decreases the risk associated with annual or more frequent examinations.

How is a low-dose CT scan different from a regular CT scan?

A low-dose CT scan uses a smaller amount of radiation as compared to a regular CT scan. Low-dose CT scans are often used for certain types of screenings, like screening for lung cancer, because a low-dose CT scan minimizes the exposure to radiation while still providing detailed images for early detection.

What happens during a low-dose CT scan that makes it unique?

A low-dose CT scan reduces the amount of radiation exposure a patient receives during the scan. This type of scan still provides detailed images for diagnostic purposes, helping detect abnormalities at an earlier, more treatable stage.

Radiation and CT scans

Everyone knows radiation is harmful. However, some exposure to radiation is necessary to get the detailed images healthcare providers need to diagnose serious illnesses, such as cancer. Let’s learn more about radiation and CT scans.

What exactly is radiation from a CT scan, and why should I care about it?

A CT scan uses what’s known as ionizing radiation. It is radiation powerful enough to pass through your body to create clear images on a computer. This type of radiation could raise your chances of cancer at some point in the future, but it’s important to understand that radiation is an important part of why CT scans are so vital to the diagnostic process.

Remember that ionizing radiation is around us every day, and it’s a natural part of our environment. For example, cosmic rays from outer space and radon gas from rocks and soil also expose us to radiation. This is known as background radiation. CT scan technology uses small doses of radiation to accurately diagnose many illnesses.

How does a low-dose CT scan use less radiation?

A low-dose CT scan emits only one-fifth of the radiation of a regular CT scan, making it safer for routine testing.
Technically, a low-dose CT scan emits about 1.4 millisieverts (mSv) of radiation (the scientific unit for measuring ionizing radiation), while a standard diagnostic CT scan is closer to 7 mSv. The average background radiation a person may be exposed to in a year is 3 to 5 mSv.
In scanning for lung cancer for example, the low-dose CT scan uses a lower dose of radiation because it is designed to evaluate nodules in low-density lung tissue, but is less effective in evaluating bones, organs or other tissues.

Why is it good to reduce your radiation exposure?

Radiation can affect the body in a number of ways. The health effects depend on the amount of radiation absorbed by the body (the dose), the type of radiation, and how and for how long a person is exposed.

In large doses, radiation can cause serious illness or skin burns, so it is always good to reduce your exposure to radiation.

In the medical field, however, ionizing radiation has become a vital tool used for the diagnosis and treatment of a variety of medical conditions. In most cases, the effects of exposure to low doses of radiation are inconsequential.

Why choose a low-dose CT scan

There are several reasons for a person to choose a low-dose CT scan. A low-dose CT scan is sometimes preferred because it exposes patients to less radiation as compared to standard CT scans. This reduces the potential long-term health risks while still providing highly detailed images for diagnostic purposes.

In what situations are low-dose CT scans the better choice?

Low-dose CT scans are often preferred for routine screening or in situations where minimizing radiation exposure is crucial, such as lung cancer screening, in pediatric cases, or monitoring conditions like pulmonary nodules.

Low-dose CT scans offer a balance between image quality and a lower radiation dose, making them suitable for certain specific diagnostic purposes.

What are the limitations of low-dose CT?

It is true that low-dose CT scans have reduced radiation exposure as compared to standard CT scans, but they still pose some risks, including a decrease in image quality, reduced sensitivity for certain conditions, and the possibility of false positives or negatives.

Therefore it’s important to weigh the benefits and risks in having a low-dose CT scan. Make sure you talk to your healthcare provider about these limitations, or any other concerns you may have.

Can low-dose CT scans spot health issues as well as regular scans?

A low-dose CT scan has only one-fifth of the radiation of a regular CT scan, making it safer for routine testing.

Low-dose CT scans are effective for certain health screenings, but they may have some limitations compared to regular scans in detecting certain conditions.

The choice depends on the specific health concern and your healthcare provider’s recommendation.

What you can expect from your scan

Before you get any type of imaging scan, it is important to know what you can expect from the scan, which will lessen your stress level and make for a more productive result.

What should I expect when I go for a low-dose CT scan?

During a low-dose CT scan, you’ll lie on a table that moves through the scanner. It’s quick and non-invasive, usually lasting only a few minutes.

You might need to hold your breath briefly. If you have any questions or concerns, make sure you review them with your healthcare provider or the technician before the scan.

Is there anything different I need to do to prepare for a low-dose scan compared to a regular one?

In most cases, the procedure for a low-dose CT scan is very similar to a regular CT scan. It is important, however, to ask any questions you may have and follow the instructions of your healthcare provider and the scan technician.

What should I keep in mind about my safety and comfort during and after the scan?

Make sure you inform the technician of any allergies you may have. Also, wear comfortable clothing, remove metal objects, and stay still as you can during the scan.

It is wise to drink plenty of fluids afterward to flush out any contrast material, if it is used. If you have specific concerns, talk to your healthcare provider.

How to schedule a CT appointment with us

Reach out to us at American Health Imaging, and we’ll help you schedule an appointment at an imaging center near you, today.

We’re here to help you get the answers you need.

Frequently Asked Questions

How is a low-dose CT scan different from a regular CT scan?

A low-dose CT scan uses less radiation than a regular CT scan, typically resulting in lower image resolution but is safer in terms of radiation exposure.

During a low-dose CT scan, the X-ray beam intensity is reduced, decreasing the amount of radiation used without significantly compromising image quality.

Radiation from a CT scan is ionizing radiation that can potentially cause cellular damage, and it’s important to minimize exposure to reduce health risks.

A low-dose CT scan employs advanced imaging techniques and technology to use a lower radiation dose while maintaining image quality.

Reducing radiation exposure is beneficial as it lowers the risk of potential long-term effects like cancer, especially with repeated imaging.

Low-dose CT scans are often preferred for routine monitoring, in pediatric cases, or for patients requiring frequent imaging to minimize radiation risks.

The limitations of low-dose CT include potentially less detailed images and a possibility of missing very small abnormalities.

Low-dose CT scans can effectively spot many health issues, but in some cases, regular CT scans might be needed for more detailed imaging.