Decoding the Megalix Cath/Angio X-Ray Tube

If your facility uses a Siemens cath/angio lab like the Axiom Artis, the Multistar, or the Angiostar, you've got a Megalix X-ray tube. As with any X-ray tube, the Megalix will require replacement from time to time. When you start to shop around for your replacement, you're likely to come across a variety of product descriptions for the types of Megalix tubes in circulation. These descriptions are made up of numbers and abbreviations that might not make a whole lot of sense at first. We've broken down what they mean so that you can be more informed as you make your next major component purchase.

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Megalix Cath Lab Tube Numbers


Pictured below is an example tube from the Megalix series with its full description. You're probably already familiar with the fact that each part has its own part number (p/n), so we'll focus on all those digits and letters that show up after "Megalix".


Other Examples

Bearing Type

There are two kinds of bearings in Megalix tubes: ball bearings and liquid or "CAT" bearings. These bearings create smooth rotation for the anode in the tube. If a tube you're looking at is like the example, it has ball bearings. If the description has "CAT" in it, it has liquid bearings. It's worth noting that, in recent years, the manufacturer has transitioned to liquid bearings in all Megalix tubes. A non-CAT tube is likely to be a bit on the older side and, therefore, a bit on the more affordable side.

Maximum kV

Up next in the description will be a series of numbers separated by slashes. The first number in this series (125 in our example) is the maximum power level the tube can be used at, expressed in kilovolts (kV).

Maximum kW

Following the maximum kV rating, will be either two or three more numbers (15/40/80 in our example) that correspond to the number of filaments (focal spots) in the tube. Each of these filaments corresponds to a different level of image resolution. The numbers indicate in kilowatts (kW) the maximum power at which an exposure can be taken within each of these resolution levels. Two-filament tubes are generally used in angiography applications while three-filament tubes are used in cardiac applications. 

Cooling Connection

After the kV and kW ratings you'll see either 121GW, 122GW, or 123GW. These indicate which type of cooling unit connection is compatible with the tube. These are not interchangeable.

Need a Tube?

If you need a Megalix tube now or are simply preparing for the day when you will, we can help. Our Parts Team can find you the right tube and our Service Team can dispatch the engineering personnel you'll need to have it installed. Whatever your particular need might be, we're ready to help. Contact us to start planning your next solution.

Decoding the Megalix Cath/Angio X-Ray Tube


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Garth Immelman

Garth Immelman is a Parts Customer Service Representative Team Lead at Block Imaging. He views every day as an opportunity to grow in his role, supplying the industry with and educating it about the parts that keep their equipment going. Outside of work Garth enjoys spending time with his wife, finding ways to make huge bonfires, and traveling to Traverse City, MI.