Our Rental, Service and Parts teams are available to serve urgent needs during the COVID-19 outbreak.
Please contact 517-668-8800 for immediate assistance.

View Rental Options

>> Buy & Sell Now

Contact Us

 Your Guide to Medical Imaging Equipment

Enjoy these tips, tricks and insights that answer 100's of questions we've received from radiology and imaging professionals that need help buying, selling, servicing and maintaining their medical imaging equipment: MRI, CT, C-Arm, Digital X-ray, PET/CT and Women's Health. We extend the life of imaging equipment so that healthcare providers worldwide can extend the lives of patients. This is why we answer your imaging equipment questions.

~ Block Imaging Team

Correcting CT Scanner Artifacts: Streak Artifacts

Posted by LaToya Beasley

Jun 16, 2020 4:00:00 PM

:: 2 minute read ::

refurbished-ge-ct-scannerGenerally, images produced by CT scanners are accurate representations of the scanned object. The technology is a mainstay in the imaging stables of most hospitals. In spite of this, CT is commonly susceptible to a number of image anomalies1, including streak artifacts.

What Is a Streak Artifact?

The name should suffice to tell you what a streak artifact looks like, but the causes bear some explanation. Most streak artifacts occur near materials such as metal or bone, primarily as a result of beam hardening and scatter. These phenomena produce dark streaks between metal, bone, iodinated contrast, barium, and other high-attenuation materials. Bright streaks are seen adjacent to the dark streaks2. See an example of an artifact caused by beam hardening below.3

ct-streak-artifact-exampleHere's an analogy to help understand beam hardening: Pretend I’m swimming across a pool. I am an X-ray beam and the pool is the part of the body being scanned. As I swim, I lose energy as I cross the pool; I’m more tired the further I go. And if I’m swimming through water, I expend less energy than if I were swimming through, say, Jell-o. In the same way, X-rays lose their energy, or "harden", more quickly as they pass through metal or bone than as they pass through muscles or organs. 

The other big issue that causes streak artifacts is something called Compton scatter. Basically, scatter causes X-ray photons to change direction and change energy. This means photons could end up in a different detector than they should be in. The biggest problem is when scattered photons end up in a detector that would usually have very few photons. For example, if a metal implant blocks all photons, then the corresponding detector element will only detect scattered photons2 

How to Correct Streak Artifacts

Streak artifacts can be reduced using newer reconstruction techniques or metal artifact reduction software. A radiologist can also try scanning at a higher kV in order to get a harder X-ray beam and thus, fewer beam hardening artifacts. However, there is a tradeoff in that the higher kV will reduce the tissue contrast of the scan2.

If your reconstruction techniques and reduction software are current and your radiologist is scanning with the highest kV they are comfortable with and streak artifacts are still appearing, it's probably time to call in a service engineer to diagnose underlying causes.

Whether you simply need service on your CT scanner or if you're ready to upgrade your CT capabilities, we can help answer your questions. To learn more about CT service and maintenance, check out our CT blogs or any of our free resources.

Request Non-Contract Service


1. https://www.appliedradiology.com/  

2. http://www.edboas.com/science/CT/0012.pdf

3, http://www.radtechonduty.com/2017/03/ct-scan-artifacts.html

Written by LaToya Beasley

author of blog post

LaToya Beasley is a Service Coordinator at Block Imaging. She enjoys the challenge of getting a failing system running again and the satisfaction that comes from helping medical professionals help patients. Out of the office, LaToya enjoys travelling, shopping, and crafting.

Topics: Imaging Equipment Service, CT Scanner

Post a Comment Here

Search this site

Get medical imaging equipment insights delivered straight to your inbox. Subscribe below.

Resources, videos, and tools to learn more about your project
Meet the Block Imaging Team
See Imaging Equipment Prices

Questions? Ideas? Imaging project you'd like to discuss? Let us know!