The Ultimate Buyer's Guide for Purchasing How X Ray Work

Every radiology clinic is incomplete without a x ray machine. Every clinic always has druthers whenever it comes to the x ray and other imaging equipments. There are a lot of reasons why a clinic chooses one brand over the other.

Consistency in finding success with digital imaging is a very important thing if you want to become a trustworthy and reliable clinic. The machines and radiology equipment a clinic uses has to be able to capture quality images and the process needs to be fast leaving no uncomfortable feeling for the patient. Thus, what kind of machinery you are choosing is a very important aspect if you want to be successful.

So how can you find the best value when considering to buy a X Ray Scanner?

Here are a few things you may consider to look into while searching for the best equipments. Check out the points below.

Concentrate on the basics:

• While buying a medical x ray equipment, you need to start from the ownership cost.  It is a very important to check the cost of ownership before you opt for buying a digital x ray equipment. Another important point you should keep in mind while opting for the equipment is the upfront cost.
• Always remember what are your needs? Why are you opting for an equipment? Is it for practicing purpose? Or is for the dentistry or the orthopedic specialty? Upfront cost, continuing support cost, budgetary concerns will always depend on these questions. So, you need to take these aspects seriously before opting for one of those machineries.
• However, looking at pricings only before buying an equipment may lead you to a machine that does not meet your needs. So, there are also other aspects you should look into. Some of them are the diagnostic capabilities of the equipment. Diagnostic capabilities of the equipment, again, may vary with the reasons you need the equipment for. The reliability is another important thing you may want to consider before opting for an x ray scanner. How many days or years it will work properly before you need to buy a new equipment again? Now that is a question to consider before you are going to buy a machine.
• Also, look for the quality of the product. As long as you are serving as a health provider, you should consider having the best quality at your radiology center.
• High-quality images are the most important thing to look for in a new x ray equipment. The x ray imaging has to be very clear.
• Safety is another concern for an x ray equipment. Because x ray waves are harmful, you should be lowering the composure for your staffs. Safety should always be a factor. Experts will advise you to buy equipments that has cesium iodide panels rather than the gadolinium oxysulfide.

So, these were the points you may want to consider before opting for a new x ray machine. Check out the list and have your own deep research about different brands before you opt for a new machine. However, if you are a patient near Morristown, New Jersey and is searching for a radiology center, don’t look any further. The Radiology Center At Harding is here to help you. 

Buying a scientific instrument can be a confusing and intimidating process because they are expensive, and many technical aspects are involved in selecting the right tool. While working with customers in the X-ray CT (computed tomography) industry for almost twenty years, I learned what confuses them and makes this buying process difficult. Buying a new CT scanner should be exciting, not confusing, intimidating, or overwhelming. In this blog article, I am going to answer the following questions and hope to help you enjoy your X-ray CT shopping experience:

1. What is an X-ray CT scanner

X-ray CT is an imaging technique that can non-destructively scan the three-dimensional density distribution of an object and reveal internal structures. You might be more familiar with the medical CT scanners that can reveal bones and organs in our bodies. The principles of medical and industrial CT scanners are essentially the same. However, while the resolution of the medical CT scanners is in the submillimeter to millimeter order, micro-CT and nano-CT scanners can achieve micrometer to tens to hundreds nanometer order resolution. You can use this technique to study anything from composite fiber orientations, plant phenotypes, bone structures, sandstone grain sizes, or void and crack distribution in plastic and metal parts.

        Read: What is micro-CT?

If you are already using radiography (two-dimensional X-ray imaging), you might be wondering, "what's the difference between 2D radiography and CT?" The example below shows a 2D radiograph and CT image (3D rendering and cross-sections) of a foam. All of the pores in the foam are projected on top of each other in the 2D radiograph. It makes it impossible to analyze individual pores. Meanwhile, the CT images show the foam as it is. You can see individual pores and analyze their shapes and sizes with no problem. In other words, CT removes all the difficulty of interpreting 2D radiographs.

2. When is X-ray CT useful?

If you need to image an internal structure of something non-destructively, X-ray CT can be useful. For example, you can see cracks and aggregates in a drug tablet. Or you can inspect 3D printed objects with intricate internal structures. If you use electron or optical microscopes and need an alternative or complementary technique that provides 3D images instead of 2D, or you want to avoid sample sectioning, drying, staying, coating, etc., X-ray CT can be useful. (See application examples in various industries.)

Application examples: from the left – drug table, calcite drill core, insect, bottle cap

But X-ray CT has its limitations, and it is important to know its pros and cons:

Pros

• Non-destructive

• Three-dimensional information

• Virtually no special sample preparation

Cons

• Limited sample size and density

• Limited resolution

• No elemental information

X-ray CT is an X-ray absorption contrast imaging. So X-rays need to get through the sample to generate a useful image. If the sample is high-density (heavy-absorbing) or very thick, X-rays will struggle to get through. An entire car engine is about the limit of the general industrial X-ray CT scan technique to give you an idea.

The resolution of most laboratory X-ray CT scanners is limited to microns to submicron. By using special optics, such as Fresnel zone plates, often combined with synchrotron radiation, you can achieve about 20 nm resolution. You need to switch to electron microscopes to achieve nm resolution.

Also, it is worth noting that X-ray CT only gives us relative density information. So you cannot identify the chemical compositions or elemental makeup of the sample. If you know what types of materials are included in the sample, then you can match each gray level in the CT image to a corresponding material. For example, in CFRP (carbon fiber reinforced polymer), the lightest gray is carbon fibers, the middle gray is the binding polymer, and the dark gray is air.

3. What types of X-ray CT scanners are available?

An X-ray CT scanner consists of an X-ray source, detector, sample stage, and radiation enclosure. Depending on the required voltage and X-ray focus size, different X-ray sources are used, including reflection or transmission microfocus sources, rotating anode microfocus sources, or synchrotron radiation. Generally speaking, high voltage means high energy for X-ray sources. For micron to mm resolution systems, a flat panel or linear detector is used. Standard micro-CT and high voltage industrial CT scanners use either the cone beam or fan beam geometry, and the X-ray divergence magnifies the sample images. For higher resolution, the parallel beam geometry with an optical lens or Fresnel zone plates are used.

High-voltage industrial CT scanners tend to be on the expensive side, about half a million to multi-million dollars, depending on the required voltage and level of automation. This is because of the high price of a high-voltage X-ray source and a large sample stage and radiation enclosure to accommodate large and heavy samples. Standard micro-CT scanners are one of the most affordable. For a research-grade micro-CT scanner, the price ranges anywhere from mid-200K to half a million dollars. Compact benchtop-type scanners are also available in this class. Nano-CT scanners are relatively expensive and range from about half a million to two million dollars, depending on the required resolution. There are many CT manufacturers. For example, Rigaku makes nano- and standard micro-CT scanners, and companies like Yxylon and Nikon make high voltage industrial CT scanners.

A benchtop micro-CT scanner: CT Lab HX exterior (left) and sample stage (right) 

        Read: How Much Does a Micro CT Scanner Cost?

4. How do I choose the right CT scanner?

The right CT scanner type depends on the sample type and size of the features you want to image. There are three major specifications to consider: X-ray energy (or voltage), field of view (FOV), and resolution. The FOV is the area you can scan, and it is normally similar to the sample size. The table below summarizes the sample factors and X-ray CT specifications:

Sample factors

CT specifications

What does this mean?

Density

X-ray energy

For example, a piece of 30 mm thick steel needs a high-energy/high-voltage X-ray source, 200 kV or above.

Small to medium-sized aluminum, ceramics, plastic, etc., need only a standard voltage X-ray source, 60-160 kV.

Organic materials can benefit from low-energy (5-20 keV) nano-CT.

Sample size

FOV

X-ray energy

FOV should cover the area you want to scan. It should be similar to the sample size.

Large samples need a high-energy/high-voltage X-ray source, 200 kV or above.

Smaller samples need only a standard voltage X-ray source, 60-160 kV.

Resolution

Spatial resolution

The spatial resolution needs to be equal to or smaller than the size of the features you want to see.

The optimum X-ray energy depends on the sample density and thickness X-rays need to get through. Generally speaking, for larger or heavier samples, such as steel or copper thicker than a few mm, you will need high-energy (100 - 400 keV). Small to medium-sized (5~200 mm) plastics, polymers, composites, wood, etc., or small (a few mm) and light metals (aluminum for example), medium-energy X-rays (20 - 100 keV) work well. For relatively small (1~10 mm) organic materials, foams, etc., low-energy X-rays (5 - 20 keV) work best.

For the FOV and resolution, keep in mind that the spatial resolution is limited to about 1/1000 of the FOV. This is because the number of pixels on commonly used X-ray detectors is limited. (Learn more about resolution. à this will link to a resolution blog article.)

Regardless of the technical requirements, the instrument size and price are always important. If your lab space is limited, a benchtop system can save a lot of space. Always check the dimensions and weight of the system. CT scanners can be heavier than they look because of the thick metal radiation shield stopping the high-energy X-rays. For the price, as summarized in the previous section, the standard micro-CT scanners are the most affordable. The higher X-ray energy or resolution is required, the higher the price becomes.

Lastly, you should always ask the manufacturer to scan a few representative samples of yours to make sure that you are happy with the image quality. If you are new to CT and considering purchasing your first CT scanner, I would also recommend that you visit the manufacturers either in person or via a video conference to have a live demonstration to really understand what is involved in running the instrument.

If you have questions or would like to try one of Rigaku's CT scanners, talk to one of our CT experts by clicking the “TALK TO AN EXPERT” button at the right top of the page or contact us at imaging@rigaku.com.

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