Even the most cutting-edge X-ray-based technology is useless without a tube to keep it running. While many leading CT manufacturers like Siemens, GE, Canon, and Philips build their own tubes, there are other companies with a more singular focus on tube production.

Some companies, (like Varex, Chronos Imaging and Dunlee) provide tubes to manufacturers and also serve the replacement and refurbished market. Others (like Richardson Healthcare) focus exclusively on replacement tubes without original equipment manufacturer (OEM) partnerships.

HealthCare Business News checked in with some of the leading tube companies to find out how technology is evolving, what innovations are happening with tube maintenance and service training, and how the global supply chain’s recent woes factor into all of this.

Quieter, longer lasting LMB tubes
For several years now, a trend toward liquid metal bearing (LMB) tubes has defined the higher-end CT market. Dunlee, a brand of Philips and leading CT tube manufacturer, serves the OEM and replacement markets, and has been focused on expanding the reach of its LMB tube, bringing it to more radiology departments around the U.S. and Europe, says Guido Stoeckmann, regional sales manager for Dunlee.

Dunlee’s DA200P40+LMB tubes, designed for GE Revolution Evo and Optima CT660 CT scanners, are manufactured in Illinois through a partnership with Chronos Imaging and have been well received by servicers and providers seeking an alternative to OEM tubes.

“We’re finding that facilities with high patient throughput are seeking LMB technologies, and they’re also well-suited to emergency departments given their ability to be instantly ready, without needing to wait for the anode to speed up,” says Stoeckmann. “LMB CT tubes are prized for their long life, made possible because the liquid metal bearing doesn't create friction, so there is less wear. The tube also features a quieter sound pattern for smooth operation and a pleasant patient experience.”

Another key advantage of LMB tubes is that they’re more conducive to removing heat from the tube, which can improve throughput and scanner life, says Pat Fitzgerald, president of Chronos Imaging. His company serves the replacement and OEM CT tube markets, and is the contract manufacturer for LMB tubes for Dunlee.

For all their benefits, LMB tubes are still mostly reserved for higher-end CT scanners. Other systems remain well served by conventional ball bearing tubes, which are more affordable.

“The cost of developing [LMB] technology is significant, and we are looking for the specific tube that will provide enough replacement volume to make a business case with sufficient return on investment,” says Jerald Olsen, vice president of sales, operations, and business development at Richardson Healthcare, a tube manufacturer that focuses exclusively on independent service organizations, resellers, and healthcare providers.

In recent years, Utah-based OEM and replacement tube manufacturer Varex introduced LMB technology to its portfolio with a dual-ended CT application tube, the GS-547XX-L and the first-to-market anode-end-grounded cardiovascular applications tube, the FP-309X-L.

A few words on ‘bread and butter’ tubes
Compared to those in CT systems, which subject X-ray tubes to incredible stresses caused by high energy and high rotation speeds, the X-ray tubes used in radiography, fluoroscopy and mammography are relatively small, compact, and inexpensive. David Hurlock, founder of X-Ray America, the exclusive U.S. distributor for Italy-based IAE, the biggest independent X-ray tube manufacturer in Europe, calls these “bread and butter” tubes, fundamental necessities for the most common imaging modalities.

IAE manufacturers 10,000 glass X-ray tubes per year for OEMs like GE, Fujifilm, Philips, and Agfa, as well as service companies. “Most independent X-ray tube manufacturers offer metal ceramic tubes for CT scanners, and either don’t offer glass X-ray tubes, or offer them as a secondary product line,” says Hurlock.

Although the advantages that LMB tubes yield for CT tubes do not apply to conventional X-ray tubes, there are other emerging technologies improving the next generation of systems.

“Innovative manufacturers use techniques like cone beam CT and tomography to offer smaller and simpler X-ray systems that capture movement, or produce 3D images without conventional CT, and with a much smaller X-ray tube,” says Hurlock. It’s a trend he calls “accommodative imaging” and believes will be a growth area for conventional glass rotating anode X-ray tubes in years to come.

The basics of X-ray tube maintenance
The main rule of tube longevity is not unlike a rule most people know will extend the life of their automobile. “If you jump in your car, and race to the corner market every day, taking short, fast trips without warming up your engine, the car won’t last for as many miles as a car that is warmed up, and then taken on long trips at a constant speed,” says Hurlock. “X-ray tubes are similar in that high exposures without warming the tube shorten its life.”

Also, like a car, scheduled preventive maintenance (PM) on the imaging system will prolong the life of the X-ray tube. “Do PMs more often,” advises Fitzgerald, because although it means more time invested on the front end, it returns to you on the back end through better performance.

So, what does preventive maintenance actually consist of? Olsen recommends the following four things be covered in PMs every three months:

Recalibrate IF data value – Updating the X-ray tube IF data keeps the X-ray tube and detector calibrated and keeps the tube output and the detector synchronized over time.

Heat exchanger checks – Visually check and clean the heat exchanger. The filter should be removed and cleaned with a vacuum and should be replaced if clogged.

Check the high voltage cable retaining cap and gap – Check the retaining cap and the tightening screws for looseness. The gap between the cap and the tube should be between 2mm and 4mm.

Leakage checks – Confirm that there is no coolant leakage from the X-ray tube, heat exchanger, or rubber hoses. If coolant leakage from the rubber hose is detected or a crack is found in the hose, replace it immediately.

“None of these items should come as a surprise, but the reality is that CT tubes will have a longer life if these simple things are done,” said Olsen. “We train and assist customers with these proactive maintenance steps daily.”

Teach an in-house team to fish…
One of the best ways to save money on tube maintenance is to train in-house servicers to do most of the work, reducing your dependence on the service provider. Richardson offers customized, hands-on training classes year-round in South Carolina for various models of Canon CT systems.

This year, Richardson released its ALTA 750G X-ray tube for sale, a replacement for the Canon CXB-750G X-ray tube that is used in the Canon Prime II, and Prime SP CT systems.

“We have a great training facility with over a dozen CT test bays where every student will get one-on-one, hands-on training from a veteran engineer,” says Olsen. “Our comprehensive program gives students an overview of the Aquilion CT series and provides training in system operation, installation, preventative maintenance, calibration, diagnostic procedures, troubleshooting, and repair. Graduates will be able to meet and exceed all service requirements for the Aquilion CT platforms.”

For servicers using Dunlee tubes, the company has a cooperation with AllParts Medical where engineers from around the world receive theoretical and hands-on training at its specialized training facility in Nashville, Tennessee to arm them with the necessary skills to make improvements and repairs efficiently.

“One best practice for extending the life of a CT tube is adjusting exam protocols, which is a valuable way to optimize equipment use and scheduling without impacting image quality and clinical value,” said Stoeckmann. “For example, by optimizing CT protocols, radiology departments can minimize stress on the tube and reduce cooling between exams.”

Supply chain challenges and repercussions
Logistics issues have hampered the CT tube market in recent years. Throughout the pandemic there was more demand for CT tubes than could be met, resulting in a backlog that experts hope may now be starting to ease. It isn’t just the complete tubes that have become scarce, but the ingredients that go into creating them.

“Besides logistic moving around the world, many raw material prices have gone through the roof and are becoming harder and harder to get,” says Fitzgerald. “In some cases, cost of components went up 40-50%, whether or not prices come back down to Earth remains to be seen.”

As part of this supply chain disruption, scanner manufacturers are having trouble accessing the chips necessary for their new technology, which has boosted interest in the pre-owned market, according to Fitzgerald. Consequently, scanners that previously might have been stripped for parts have found new life in outpatient centers or rural hospitals, leaving fewer pre-owned parts available for harvesting.

In other words, it’s all demand and no supply. This state of affairs if forcing tube manufacturers to start thinking differently in order to remain competitive.

“One solution we’ve found to mitigating supply chain-related issues is consistent recycling of components and raw materials,” said Dunlee’s Stoeckmann. “In addition, a future-oriented and cross-platform product design is critical.”

Going where you’re needed most
One way that tube manufacturers are pivoting to address these challenges is by expanding their presence in new markets. That can mean receiving certification to do business in a new country or bringing manufacturing capabilities into a new, strategic location.

X-Ray America is building an X-ray tube manufacturing facility that will utilize IAE technology and quality. IAE will continue to supply OEMs with tubes directly from their manufacturing facility in Italy, says Hurlock, while the U.S. distributor will manufacture and hold inventory for the just-in-time needs of the service industry.

Richardson is also expanding its footprint. By becoming MDSAP-compliant and registering with the Canada Health Ministry as a medical device manufacturer, the company can now sell new replacement tubes into Canada.

Chronos is finalizing paperwork to be compliant with new MDR standards for doing business in the European Union, and may be one of a few companies able to sell tubes in that market. It is also expanding in China with a manufacturing facility in Shanghai.

A lower cost, higher performance tube market is on the horizon
The current economic climate and supply chain disruption are testing many aspects of the healthcare ecosystem, and X-ray tubes are a part of it. Despite these challenges, there are reasons to be hopeful about the future of the industry.

According to Fitzgerald, there is a very real opportunity in the market for more affordable, longer-lasting tubes for serving lower-end CT applications and systems. Advances in X-ray detector technology mean that imaging can be done with less power and less dose for equivalent diagnostics. “Most manufacturers use a 3.5m heat unit compared to 5m or 6.3m heat unit a few years ago,” said Fitzgerald. “3.5m tubes are cheaper to make but get the job done.”

As the replacement tube market works to leverage the advantages afforded by new X-ray detectors for lower-end scanners, it will also be watching the market expand for high-end LMB tubes.

“As imaging departments continue to face tremendous pressure to keep healthcare accessible and reduce operating costs, long-lasting, high-quality alternative X-ray tubes are helping them reach their goals, and the demand for these tubes will increase in future,” said Stoeckmann. “Many CT scanners with LMB tubes are running out of warranty, and related service contracts with the OEM will be accessible for independent service providers in the future.”