Guide to Computed Radiography

Jump to:

• What is Computed Radiography?
• Benefits of Computed Radiography
• Components of Computed Radiography
• How Does Computed Radiography Work?
• How is CR Different from Traditional X-Ray Testing?
• Applications of Computed Radiography

Non-destructive testing (NDT) is critical for ensuring compliance with quality standards and industry regulations. For many businesses, conventional X-ray testing is still the preferred method. Implementing newer technology can help to bring your business into the 21st century.

If you’re looking to modernize your NDT processes, switching from conventional film X-ray testing to computed radiography (CR) may be ideal. CR has many advantages over traditional X-ray imaging, which can benefit your business.

This guide to using computed radiography for NDT covers everything you need to know.

 

What Is Computed Radiography?

Computed radiography (CR) is a form of digital radiography testing for NDT that replaces traditional X-ray imaging. Unlike traditional X-ray systems, which use film, CR systems use photostimulable phosphor imaging plates to capture images.

Upon radiation exposure, the plate captures an image of the test object, which is CR’s main similarity to X-ray film testing. Instead of going through darkroom processing, the CR system uploads the image to a computer program for analysis. This program allows you to make adjustments and apply digital enhancements as needed to make analysis easier.

The Benefits of Computed Radiography

Companies looking for a sustainable, cost-effective, non-destructive testing method can benefit from computed radiography. The main advantages of using CR include the following:

• Time savings: It only takes a few minutes to process images using CR technology. This rapid turnaround time can help technicians boost testing efficiency and throughput.
• Cost-effectiveness: CR imaging plates are reusable almost immediately after erasure, so you can save money on imaging materials.
• Sustainability: Reusable plates help reduce consumable usage. As a result, switching to CR can help businesses become more environmentally and financially sustainable.
• Chemical-free: Unlike traditional X-ray radiography, CR systems do not use developer solution to produce an image for analysis. Using CR eliminates the need to store processing chemicals, freeing up space and reducing overhead costs.
• User-friendly: Many operators find digital imaging software easier to work with than traditional film.
• Image quality: Unlike with X-ray film, you can adjust CR images after processing to remove background noise and improve image clarity.

Computed radiography does have some disadvantages. The risk of damaged equipment is one of the main drawbacks, as CR cassettes are susceptible to damage from mishandling or abuse. CR systems also have more intensive maintenance needs than other digital radiography methods.

However, it is also true that CR imaging is more cost-effective than other digital systems, especially for businesses entering the digital NDT space for the first time. Carefully consider your organization’s needs before choosing an NDT system.

 

What Are the Components of Computed Radiography?

Computed radiography systems comprise several hardware and software components that perform each part of the imaging process.

These are the five main parts of a CR system:

1. Radiographic generator: This device emits the necessary radiation to create an image on the plate. If the CR system is compatible with your existing equipment, you may be able to continue using your generator.
2. Imaging plates: CR systems use cassettes containing reusable phosphor plates rather than film. You can erase and reuse these plates thousands of times, significantly reducing the need for consumables.
3. Image reader: The reader replaces the darkroom of conventional X-ray testing. Rather than applying chemical solutions to an exposure to reveal the image, CR readers scan the phosphor plate and digitize the image. They then transfer the image to the workstation.
4. Workstation: Most CR radiography systems use a standard PC to view, evaluate and send digitized images.
5. Software: Diagnostic imaging software provides a consolidated platform for storing, analyzing and managing test images. This software streamlines file management and optimizes analysis processes.

Proper system maintenance is critical for ensuring high-quality test images. For example, you must erase imaging plates after each use because residual energy can create ghost images in later exposures. It’s also important to regularly erase unused plates, which can capture faint images even while not in use.

How Does Computed Radiography Work?

The name “computed radiography” can be misleading because the actual imaging process includes minimal computations. In reality, it is more similar to traditional X-ray imaging than most computer processes.

Here’s a brief step-by-step explanation of how the process works.

1. Exposure

First, you expose the imaging plate and test object to radiation to capture a latent image. This radiation may be X-rays or gamma rays, depending on your application. The energy from the radiation remains trapped in the plate’s phosphor layer.

Exposure time and image quality can vary depending on the type of plate you use. Other system components, like your scanner or display monitor, can also influence image quality.

2. Digitization

You then insert the cassette into the CR reader, which scans the plate by applying a focused laser beam to it. The plate emits a bright blue light in response, allowing the reader to pick up the image on the plate.

Using an analog-to-digital converter (ADC), the scanner turns the light into a digital signal, which it transfers to the computer. Then, it wipes the image from the plate using a high-intensity light source.

3. Analysis

Once the converter has transferred the image to your workstation, you can begin analysis. Your diagnostic software allows you to manipulate the image for more in-depth analysis. You can also reuse the plate immediately after erasure as needed. Depending on the brand of plates you use and your specific application, you may be able to reuse one plate more than a thousand times.

Your analysis software allows you to alter the image and view it from different angles to get a clear, comprehensive view of the test object. Each software program has different features and capabilities, so it’s important to choose the right one for your business. Some helpful features to look for include the following:

• Automatic measurement tools
• Digital contrast normalization
• Smooth transitions between screens
• Traceability and reliable image quality assessment
• Flexible network configuration

Ideally, your analysis software will fit seamlessly into your CR system. Choosing one manufacturer and developer for all your system components is ideal for ensuring smooth integration.

 

Why Is Proper Technique Important for Computer Radiography?

Proper technique selection allows the software to seamlessly capture the image’s details with accurate contrast and resolution, making it easier to identify defects.

One of the most important technique factors is accurate exposure. Ensure you position the imaging plate so the exposure creates a clear image. Underexposure can make it difficult to see, resulting in missed defects. Overexposure can distort defects, making it challenging to repair. The ideal positioning will minimize artifacts, enhance defect detection and accurately represent the desired area.

How Is Computed Radiography Different From Traditional X-Ray Testing?

CR radiography replaces X-ray testing by digitizing the darkroom process in just a few steps. Like X-ray testing, CR imaging uses cassette-based media and radiation to capture images — however, CR uses imaging plates instead of X-ray film.

Some other key differences between the two include the following:

• Consumables: Processing images using film requires darkroom chemicals, consistent, high-quality single-use film and other consumable materials. You can produce thousands or even tens of thousands of images through CR radiography with one set of plates, a computer and a CR reader.
• Environment: You need to keep X-ray images in a temperature- and humidity-controlled environment to prevent the film from warping or distortion. However, with CR imaging, you can store images on your workstation, eliminating the risk of image degradation resulting from environmental factors.
• Location: Film development must take place in a darkroom, which poses a challenge for many industrial facilities. As a result, many businesses using X-ray testing must process their images off-site, which adds to the processing time. Fujifilm’s computed radiography systems easily fit into narrow spaces, saving you valuable floor space and time.

While X-ray testing has been the standard in image-based NDT for decades, transitioning to a CR system can help bring businesses into the modern era. Faster processing times and easier analysis enable companies to increase testing throughput and meet deadlines quicker, which is essential for staying competitive in today’s fast-paced world.

How Is Computed Radiography Different From Direct Digital Radiography?

While CR and direct digital radiography (DR) are both digital forms of NDT, they are different techniques.

The main difference between the two is in the equipment each system uses. Where a CR system uses flexible cassettes containing imaging plates, DR systems use flat-panel detectors or digital detector arrays (DDAs) to capture images.

CR uses photostimulable phosphor (PSP) plates that are transported to a digital scanner. From there, they’re scanned with a laser beam and converted to an image. Conversely, DR uses a combination of a light-emitting phosphor and a digital converter. In theory, DDA is faster, but the reality doesn’t always play out that way.

DDAs convert applied X-rays into electrical charges, which enter the transistors and produce a digital image in real time. It’s a common misconception that DDA is faster because that’s only true when looking at defects that do not have stringent requirements. Depending on the specifications, inspecting certain defects requires geometric magnification, which requires more shots to reach the necessary resolution.

Another key difference is in the spatial resolution. CRs can go down to 25 um, but even the best DDAs only go to about 100 um, and it would take longer to get these smaller shots on a DDA. If you need to work with smaller defects, a CR would be quicker and more efficient.

One prominent difference that makes many companies choose CR is that DDA panels don’t wrap around pipes or round surfaces. To get them around these surfaces, you’d need to attach them using some kind of fixture. So, even though DDA may be faster with bigger defects, it still takes more time because of these little nuances. CR doesn’t have this issue. The image plates are flexible and wrap around cylindrical or round surfaces easily.

Industrial Applications of Computed Radiography

Computed radiography applications include almost any NDT process involving X-ray radiography.

Typically, CR is best for smaller companies with low-volume testing needs due to its low startup costs. It can be useful for businesses in most industries, including the following.

Aerospace

The aerospace industry must adhere to stringent safety and quality regulations to protect passengers and cargo. Aircraft frequently travel through demanding environments that can accelerate wear and tear on sensitive internal components. Radiography testing is essential for catching defects early before they can lead to catastrophic failure.

CR can help manufacturers verify their airplanes’ safety by testing for subsurface defects. It’s also useful for identifying and monitoring signs of aircraft fatigue without causing additional damage to the plane’s delicate internal structures.

Automotive

Digital radiography techniques like CR and DR provide rapid results, which means they’re suitable for use in automotive manufacturing facilities. Implementing CR testing in-line speeds manufacturing by eliminating the delays common to destructive testing methods.

Because CR virtually eliminates consumable usage, it may also reduce supply chain issues that can interfere with timely vehicle production.

The speed of computed radiography can also help technicians improve repair and maintenance efficiency. Technicians can test the affected vehicle or component, then quickly pinpoint the source of the problem using advanced analysis software. Faster repairs can significantly improve customer satisfaction and increase profits.

Construction

Computed radiography can help construction companies modernize their operations by digitizing inspections and image management.

Like conventional X-ray equipment, CR systems help construction professionals detect and identify internal structure characteristics such as voids, wire mesh and cooling lines. They’re also especially valuable for inspections of castings, welds and other components that are vital for the safety and efficiency of construction workers.

CR digital images allow technicians to adjust for clarity and identify defects more clearly. Certain software also comes with filters that make it easy to pick up defects quickly. It can save technicians time and improve customer satisfaction.

Compared to film, digital imagery doesn’t take much physical space and doesn’t need a climate-controlled environment. CR creates digital images of around 10 megabytes that fit easily onto most hard drives, DVDs, CDs or network servers. Technicians can easily search for the file name and access the image — no need to dig through drawers.

Another benefit of using CR in construction is it allows team members to communicate remotely. For instance, if a technician in another area needs a radiograph of a particular weld, you won’t have to arrange to travel or ship the image. Technicians can simply share the file via email or upload it onto a digital platform for easy viewing.

Additionally, because CR takes less time to process images, it streamlines inspections. Site managers can keep projects moving along much quicker, allowing for faster project completion.

Gas and Oil

CR digitizes the imaging process, which can help gas and oil companies modernize and streamline testing procedures. They can also cut operational costs by eliminating the need for single-use consumables.

This digital radiography technology offers testing technicians a clear view into the health of their welds, piping and valves, enabling them to identify issues such as:

• Internal corrosion
• Corrosion under insulation (CUI)
• Poor quality welding
• Pipeline blockages
• Cracks and breakage

Technicians can share, email and digitally store the images in minutes rather than over several hours.

CR is especially powerful for this industry when combined with other advanced processing techniques like geometric magnification.

How We Can Help

If you need advanced imaging solutions for your NDT application, we at Fujifilm can help you find the right system to meet your needs.

Streamline critical NDT applications such as parts inspection and site evaluation with the Fujifilm DynamIx HR2 CR system and DynamIx VU NDT imaging software.

DynamIx HR2

The DynamIx HR2 is a compact, user-friendly CR system suitable for use in any industry. Simply insert the image plate into the reader and process your images — the HR2 will eject the plate once the process is complete. Once your image is processed, you can perform multiple analysis operations quickly and easily, allowing you to obtain a comprehensive look into your test object.

The DynamIx HR2 reads imaging plates of various different sizes, including up to 152 centimeters long. Additionally, the device’s reading density spans from 25 to 200 μm. Custom options are also available for organizations with more specialized needs.

DynamIx VU

Our industry-leading NDT imaging software provides superior CR image quality and a wide dynamic range, allowing you to analyze test images with confidence in your results. This user-friendly software suite simplifies workflow and data management, streamlining inspections and enabling you to maximize return on investment (ROI).

DynamIx VU is suitable for inspecting many different types of components, including:

• Electronics: The software is suitable for use with sensitive electronic components like printed circuit boards (PCBs).
• Automotive: DynamIx VU can help you inspect mechanical parts like rotors, crankshafts and gearboxes.
• Aerospace: Inspect welds, investment casting and other mechanical components to ensure compliance with regulatory standards.

New, advanced features can help ensure more efficient inspection. DynamIx VU Thickness, our automatic measurement tool, allows oil and gas professionals to precisely determine pipe thickness by detecting both edges of the pipe wall and taking a focused measurement.

Additionally, DynamIx VU supports a wide variety of general and industry-specific standards for automated quality assessments. You can choose which parameters to test, and the software will do the rest.

Choose Fujifilm for Computed Radiography Solutions

At FUJIFILM North America Corporation, we provide cutting-edge NDT solutions for various industries and applications. Whether you need a digital radiography solution for oil and gas pipeline testing or construction site inspection, we can help you find the technology you need to get the job done right.

We have over 300 consolidated subsidiaries worldwide, so we’re highly responsive to customer requests and passionate about providing innovative solutions to maximize customer value. Should you have any questions about computed radiography, we are the best guide for understanding your product needs.

Contact us today for more information about how our computed radiography systems can improve your operations, or browse all our NDT products to learn more about our offerings.