Technology applied: Differences and application cases of CT(Computed Tomography) scanning
In the previous sections, we provided brief introductions to CT (Computed Tomography) scanning, its practical applications, radiation regulations, and key points for equipment evaluation. Readers who have gone through these sections should now have a general understanding of CT scanning.
If you haven’t read them yet, you can click the text link below to check them out.
- Education: What is CT Scan?
- Technology applied: Industrial CT scan procedures
- Technology applied: Radiation Regulations and Assessment Points for CT Scans
In this section, we will focus on explaining various application cases related to CT (Computed Tomography).
Differences Between X-ray and CT (Computed Tomography) Scans
With the rapid advancement of technology, various non-destructive inspection techniques have been developed. In addition to CT (Computed Tomography) scans introduced in previous sections, other common imaging methods include X-ray, MRI (Magnetic Resonance Imaging), and Ultrasonography.
However, since the focus of this section is on CT scans, the following content will provide a brief comparison and explanation between X-ray imaging and CT (Computed Tomography) scanning.
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What is X-ray?
X-ray, also called X-radiation, is a type of ionizing radiation with high energy that can damage biological molecules and cells. In terms of wavelength, it is shorter than ultraviolet (UV) light but longer than gamma rays.
From a technical principle perspective, an X-ray device generates directional X-rays from the X-ray source, which are then guided to penetrate the object being inspected and projected onto X-ray film or an Imaging Plate (IP). During the imaging process, the object is usually examined using either a single-shot or continuous exposure method to confirm its structure.
In terms of technical applications, X-rays are used in medical X-ray machines for human healthcare, baggage X-ray scanners for airport security inspections, PCB X-ray machines for checking soldering conditions on PCB boards, and industrial X-ray machines for inspecting internal structural defects of industrial products, among others.
(* Quoted fromアンリツ株式会社 プロダクツ・クオリティ・アシュアランス channel)
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What is CT (Computed Tomography) Scan?
CT, or Computed Tomography scan, is also known as CT or X-ray CT (X-ray Computed Tomography).
Technically, it operates on the same principle as X-rays — using ionizing radiation (either electromagnetic waves or particles) to penetrate the object under inspection.The key difference, however, lies in how the data is processed: during the scanning process, the captured penetration data is reconstructed and reassembled by a computer into 3D images. This allows users to non-destructively examine and verify the internal structures of the inspected object. Typically, CT scanning involves continuous burst shooting over a short period to collect multiple image slices for reconstruction.
In terms of applications, CT technology — similar to X-ray systems — is widely used in medical X-ray CT scanners for human healthcare, veterinary X-ray CT scanners for animal and pet diagnostics, and industrial CT scanners for inspecting internal structural defects of industrial components, among others.
(* Quoted from RF Channels channel)
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Differences Between X-ray and CT (Computed Tomography) Scans
Although both X-ray and CT (Computed Tomography) scans utilize the properties of ionizing radiation to non-destructively inspect an object, there are distinct technical differences between the two.
An X-ray captures a 2D image from a single fixed angle — typically in a one-shot exposure. Usually, only one image is taken, and the resulting image can only be analyzed from that specific shooting angle.
In contrast, a CT scan involves either rotating the imaging device or the object itself by 360°, taking multiple continuous exposures (burst shots) within a very short time. The total number of images captured typically ranges from 300 to over 1,000 (※), and after the scan, the reconstructed 3D data allows observation and analysis from any angle or direction.
(※ The number of captured images may vary depending on the manufacturer, equipment specifications, and scan mode.)
Application Cases of X-ray CT (Computed Tomography) Scanning
As mentioned in previous sections, X-ray CT scanning technology is widely used not only in the industrial and medical fields, but can also be applied to many other areas and purposes.
But in concrete terms, how exactly is this technology utilized?
In the following sections, we will introduce several practical application cases outside of the industrial and medical domains. Through these examples, we hope to help you better understand the capabilities of X-ray CT scanning and determine whether this technology is suitable for your specific business or application needs.
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Verification of weld
This case was provided by Asano Co., Ltd., located in Ise City, Gunma Prefecture, Japan.
In the video, the technicians used an X-ray CT (Computed Tomography) scanning system to compare test pieces of aluminum welding, focusing on two types of welding techniques: MIG welding (also known as Metal Inert Gas welding) and TIG welding (also known as Tungsten Inert Gas welding).
In general, when welding, if substances such as moisture, oil, rust, or coatings on the base material are not thoroughly cleaned, they can become fused into the base material along with the filler metal during the welding process. Because these substances vaporize due to the high temperatures of welding, porosity defects (blow holes) may form between the base material and the filler metal.
In the video, the differences between MIG welding and TIG welding can be clearly observed. After identifying these differences, the technicians can review and improve factors such as surface treatment, welding methods, and the causes of defects.
For more detailed information, please refer to the video link provided below.(* Quoted from 株式会社浅野 channel)
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Research on Freeze-Thaw in Soil Pavement
This case was provided by Professor Takashi Kawamura from the Department of Water Environment and Civil Engineering, Faculty of Engineering, Shinshu University, a national university corporation in Japan.
In the article, Professor Kawamura mentions that in the past, when analyzing soil-based pavement materials made from a mixture of soil and cement, in order to simulate how moisture infiltrates, freezes, expands at low temperatures, and causes cracks in the pavement, they had to spend a large amount of time repeatedly freezing and thawing the test samples. Only by examining the fragments that broke off from the samples could they analyze the state of material degradation. During the freezing process, it was impossible to observe the internal structure.
However, after introducing X-ray CT scanning equipment, it became possible to directly observe the internal structure even in the frozen state. This greatly assists researchers in conducting more in-depth studies of soil changes during freezing.
For more detailed information, please refer to the link provided below. -
Replication of Animal Skeletal Models
This case was provided by Akio Sasaki, CEO of Ampho Joint Venture Co., Ltd. in Japan.
As mentioned in the article, unlike the traditional method of creating models by using clay or molten material to capture the shape of animal bones, the company uses a 3D scanner to obtain 3D information of the bone structure, then prints the model with a 3D printer, and finally applies manual finishing and coloring to the model.
However, because a 3D scanner can only capture the surface 3D information of the bones and cannot acquire internal details, the company ultimately chose to introduce X-ray CT scanning to obtain internal structural information in a non-destructive manner.
This approach not only reduces the workload involved in model creation but also allows researchers to obtain 3D information from precious specimens (frozen or preserved) stored in containers, without removing them, minimizing physical contact while acquiring the necessary data.
For more detailed information, please refer to the link provided below. -
Medical research
This case was reported in a medical research study by Dr. Nur Syafiqah Mohamad Ishak and colleagues at the Niigata Research Institute of Mitsubishi Gas Chemical Company, Inc., Japan.
In summary, the study involved adding the antioxidant PQQ (Pyrroloquinoline quinone) to the feed of experimental mice and using X-ray CT scanning to observe cellular-level changes over time.
As this is a medical research paper, we will not go into further detail here.
(* Quoted from Nur Syafiqah Mohamad Ishak, Midori Kikuchi, Kazuto Ikemoto. “Dietary pyrroloquinoline quinone hinders aging progression in male mice and D-galactose-induced cells”. 2024, 3-2, FIGURE 2For more detailed information, please refer to the link provided below.
- Dietary pyrroloquinoline quinone hinders aging progression in male mice and D-galactose-induced cells
https://www.frontiersin.org/journals/aging/articles/10.3389/fragi.2024.1351860/full
- Dietary pyrroloquinoline quinone hinders aging progression in male mice and D-galactose-induced cells
With this, we hope readers now have a deeper understanding of the differences between X-ray and CT (Computed Tomography) scanning, as well as the various practical application cases. We trust this information will help you evaluate and better comprehend CT scanning equipment.
This concludes the current unit on CT scanning. In the future, any additional information or updates will be compiled and shared with you. Until then, we look forward to seeing you again.
