What to consider when buying an x-ray machine?
When the time comes for purchasing an x-ray machine, many buyers with no related technical knowledge will get confused between different machines’ specification, and consequently might not be able to compare prices fairly.
To start, let’s all agree that an x-ray machine consists of two basic parts, the x-ray system for x-ray radiation and the acquisition system for receiving and reconstructing an image. Calling the machine conventional or digital depends on whether the two parts are integrated or not.
- Digital x-ray machine = x-ray system + digital acquisition system
- Conventional x-ray machine = x-ray system or x-ray system + conventional screen film (SFR)
Here is a basic explanation of the x-ray system and what features to consider when buying and x-ray machine.
I- X-ray System
The main component for an x-ray machine is the tube and how it is mounted (floor mounted, ceiling suspended or portable unit), everything else could be optional. We will start with the patient table and the common features you might need to think about.
1- Patient table (PT).
If you are a chiropractor, you wouldn’t need a patient table. If the machine is for a hospital or imaging centre, then PT would be a necessary part and you’ll need to decide which table is more suitable for your business.
- 2-way floating table: It moves in two directions, can be considered if you are a vet clinic.
- 4-way floating table: It moves in four directions, and this is the common type for most diagnostic imaging practices
- Fixed or elevating table: Fixed is more convenient for limited budgets as you might need to invest 4k-8K more for motorised elevating tables.
- Automatic Exposure Control: AEC function controls and limits the amount of x-ray exposed to patients making operators’ exposure-errors less likely to happen.
- Rotating bucky: It makes it easier to rotate the cassette or detector without taking it out of the tray. It saves time and makes the operators more satisfied, but not a necessary feature.
2- Wall Bucky Stand (WBS)
Wall bucky stands can be very basic or very advanced. Below are optional features to consider.
- Automatic Exposure Control: AEC function as mentioned in the patient table
- Fixed grid: Wall bucky stand usually comes with moving grid but can always be replaced with fixed grid. (The fixed grid doesn’t make noise as it doesn’t need to move during x-ray, better in removing scattered radiation also more durable as no communication needed between grid and x-ray during exposure but it is a more expensive option)
- Motorized movement: Most of the wall bucky stands are counter balanced but there are optional features to have them motorised for even easier lifting
- WBS tilting: Tilting the detector is always an optional feature making life easier for operators and patients, but all comes with additional cost
- Remote control of the WBS movement: Mostly available in all brands and not offered unless asked for.
- Synchronization between tube movement and WBS is a feature that limit the double work for operators as they don’t need to adjust the two parts. They just adjust the tube and the WBS will get aligned automatically. Very nice feature if you have a very big flow and you need to save time.
3- X-Ray tube mounting designs
There are mainly two options for tube/collimator mounting.
- Floor mounted/floor-ceiling mounted (No big differences, only depending on the room dimensions and set-up)
- Ceiling suspended: Provides more flexibility in tube handling and positioning. It is more convenient solution when scanning emergency or in-patients while they are on their transporting trolleys, without the need to carry them onto the patient table.
4- Generator power rating:
There are different generator power specifications depending on manufacturers. Below ranges are just to give a closer idea.
- 30KW – 50KW systems: Ideal for VETS and Chiropractors
- 50KW- 80KW systems: More ideal for hospitals and medical imaging centres.
- 3KW-20KW systems: Ideal for portable x-ray systems. From small animals to humans.
II- Acquisition Systems
In todays’ market, an acquisition system can be either through cassette readers (CR) or flat panel detectors (FPD). We will tackle a few main points to compare between both solutions and the related cost, without going in deep technical details.
- Speed: FPD takes 2-6 seconds to acquire and reconstruct an image. CR can take an average of a minute to get the one image processed depending on operators’ speed. The advantage of multiple scanning at the same time using detectors versus one by one using CR systems gives FPD superiority in speed.
- Panel handling: Although most of the recent FPD are shock tolerant, however, they should be always handled with care as there is a possibility of getting damaged if dropped from a distance. CR cassettes are much safer to use and less likely to get damaged.
- Image quality against applied dosage: One more advantage of using FPD is the image quality specially if you are using CSI detectors which can give a better image quality at less applied dosage (which is also good for prolonging the life time of your x-ray machine).
- Panel Size: FPD comes in one size of your choice, the most common is the wireless 14’X17” but there are options of tethered or wired 12x 12 inch or 14 x 17 inch or 17 x 17 inch. For the CR you can easily have the 3 sizes available with every CR system.
- Cost of ownership: When it comes to cost, CR systems win for the short-term, they can be a better choice for a new starting business or a business that has a limited number of patients every day. However, considering depreciation value, satisfaction of stuff, speed and quality of work, FPD might be a better long-term investment choice even for small business.
Disclaimer: All views and opinions expressed in this article only reflect Healthcare Diagnostics’ opinion and are accurate to the best of its knowledge.
