Liquid-metal-bearing CT X-ray tube: a domestically produced 7 mHUA product is imminent.

From core components to software algorithms, the high technological barriers in medical imaging equipment are widely recognized across the industry.

As one of the most technologically sophisticated core components of CT scanners, the CT X-ray tube remains a major bottleneck in the effort to achieve domestic substitution for high-end medical imaging equipment.

Opportunities and Challenges

China’s CT industry is currently in a mature stage of development, with its market size continuing to expand.

Data from Frost & Sullivan show that,

In 2021, China’s total CT scanner sales reached 6,889 units. By 2025, the country’s overall CT scanner sales are projected to climb to 10,445 units, with a compound annual growth rate of 11.0%.

In 2021, China’s total CT scanner inventory stood at 37,330 units, and this figure is projected to rise to 66,038 units by 2025, reflecting a compound annual growth rate of 15.3%.

The “Catalogue for the Licensing and Management of Large Medical Equipment (2023),” released in March this year, has removed 64-slice and higher‑slice CT scanners priced below RMB 30 million from the list of items subject to regulatory oversight, thereby lifting restrictions on their procurement. Going forward, 64‑ to 128‑slice CT scanners are expected to become the mainstay models in tertiary hospitals and select secondary hospitals, and they are also poised to emerge as the fastest‑growing segment within the CT market.

According to statistics from the “Medical Procurement and Bidding” platform on 2022 CT procurement data, sales of domestic CT brands have now matched those of imported brands. Specifically, the localization rate for CT scanners with 64 rows or fewer has exceeded 50%, and 64-row CT systems have entered a critical phase of domestic substitution.

Although domestic manufacturers have made significant strides in whole‑machine R&D, the high‑heat‑capacity CT tube—the key core component of high‑end CT scanners—has long relied on imported brands.

The R&D process for CT X-ray tubes is lengthy, requires substantial capital investment in equipment, spans a long development cycle, and yields slow results—making it a quintessential multidisciplinary field. Producing X‑ray tubes with stable quality and extended service life entails expertise across multiple domains, including beam optics, mechanical engineering, electromagnetics, materials science, dynamics, and heat transfer. It places stringent demands on manufacturing processes, supporting infrastructure, and process‑level equipment, while also presenting high barriers to design and production. Achieving consistent mass‑production capability is an even greater challenge for X‑ray tube manufacturers.

As 64‑slice CT scanners become increasingly widespread, liquid‑metal‑bearing X‑ray tubes are poised to become the mainstream choice, covering high-, mid-, and low‑end models across the entire CT market. Encouragingly, in recent years, numerous domestic companies have emerged in the CT tube sector, vigorously strengthening their capabilities in independent research and development as well as in‑house manufacturing. At the same time, it remains an undeniable fact that a significant gap persists: only a handful of firms can achieve in‑house production of tube assemblies, scale up mass manufacturing, and deliver performance comparable to imported brands. Beijing Zhibu Technology Co., Ltd. (hereinafter referred to as “Zhibu Technology”) is among them—and since its inception, it has boldly tackled the most challenging tasks, choosing the liquid‑metal‑bearing CT tube, long regarded as the industry’s “ceiling,” as its breakthrough point.

Breakthroughs and Innovation

The founder of Zhishu Technology has pointed out that China has already seen the emergence of a number of leading CT‑system manufacturers, and the market share of domestically produced equipment is steadily and rapidly increasing. However, in the critical components sector—where CT X‑ray tubes are emblematic—significant technological bottlenecks persist, particularly in the mid‑to‑high‑end segment, exemplified by liquid‑metal‑bearing CT tubes.

High‑thermal‑capacity liquid‑metal bearing CT tubes play a crucial role in the imaging diagnosis of numerous common diseases, including cardiovascular and cerebrovascular conditions, neurological disorders, and cancers. Achieving early domestic substitution and ensuring independent, controllable production is of paramount importance for meeting clinical needs, reducing patient diagnostic and treatment costs, and fostering the development of China’s related medical device industry.

Compared with traditional ball bearings, liquid-metal bearings offer significant advantages:

It can significantly enhance the heat dissipation rate of the X-ray tube.

Supports faster gantry rotation and imaging rates, making it more suitable for cardiac imaging.

Low wear and long service life;

Operates almost silently.

Since its inception, Zhishu Technology has been deeply engaged in key technological areas such as liquid-metal bearings and single-ended anode grounding. Currently, several of its products under development have made substantial progress: for 16- to 32‑row CT scanners, the company has successfully developed replacement X‑ray tubes—replacing the 3.5 MHU tubes used in go Now and go Up models. Zhishu Technology has overcome numerous technical challenges, integrated state-of-the-art testing equipment, and established a comprehensive test environment. By rigorously evaluating product performance and lifespan, it ensures stable product quality and an excellent customer experience. The new ZS352C X‑ray tube is now fully ready for mass production.

In 2021, Beijing Zhisu Technology became the first in China to achieve a technological breakthrough in 5 MHU thermal‑capacity liquid‑metal bearing X‑ray tubes, and has since moved to mass production.

However, a thermal capacity of 5 MHU still falls short of meeting clinical needs in medicine. CT tube rotors with liquid-metal bearings and a thermal capacity of 7 MHU or higher are urgently required by both the clinical community and the industry; yet their technological architecture is cutting-edge and highly complex, making it extremely challenging to achieve full domestic self-reliance and maintain a leading position.

Responding urgently to medical needs while bearing the burdens of industry. Building on its existing 5 MHR liquid‑metal bearing X‑ray tube technology, the Zhisu Technology R&D team, after more than a year of dedicated research and development, has successfully mastered a series of critical core technologies—including cathode electron‑gun simulation, liquid‑metal hydrodynamic bearing simulation, liquid‑metal cryogenic treatment, automated X‑ray tube assembly, and tube aging testing. In addition, the company has independently designed and developed a universal X‑ray tube test platform capable of evaluating a wide range of performance parameters, such as high‑voltage testing, cathode emission testing, noise measurement, and life‑cycle endurance testing.

The ZS702L is a newly developed medical CT X-ray tube from Beijing Zhibu Technology, specifically designed as an in‑situ replacement for GE Healthcare’s Optima series and Revolution ACE 7.0 MHU tubes (also known as the Performix40+ LMB).

At present, the ZS702L X-ray tube prototype has met all its design‑specified performance parameters and offers the following advantages:

· Higher power The ZS702L features a 72 kW anode input power, supports higher current output and longer continuous scanning durations, and can meet the requirements of coronary and other whole-body vascular examinations.

· Higher heat capacity The ZS702L features a large 190 mm target disk and boasts a maximum anode heat capacity of 7.0 MHU, meeting the demands of hospitals for high‑throughput imaging around the clock.

· Higher load-bearing capacity : The ZS702L supports a maximum gantry rotation speed of 0.35 s/r, can withstand higher centrifugal forces, and delivers superior temporal resolution, meeting the requirements of 64‑row CT examinations, including cardiovascular imaging.

· Higher quality As China’s first domestically developed CT tube featuring a liquid-metal bearing with a heat capacity exceeding 7 MHU, the ZS702L delivers reduced wear and vibration, enhanced cooling performance, lower levels of scatter radiation, a significantly lower incidence of tube arcing failures, superior image quality, and an extended service life. While ensuring high‑performance, efficient CT operation, it further improves the patient experience and lowers CT operating costs.

The ZS702L is another flagship product from Zhishu Technology, following the ZS502L and ZS402L, and will become China’s first domestically developed CT tube with a liquid-metal bearing whose thermal capacity reaches 7 MHU. According to Zhishu Technology’s current R&D schedule, the ZS702L is expected to complete NMPA registration and enter the market in 2024.

Zhishu Technology has already established sales of its X-ray tubes in Europe, South America, West Asia, and other regions, and plans to participate in several major trade shows this fourth quarter, including CMEF in Shenzhen, RSNA in Chicago, and Russian Health Care Week in Moscow, to showcase its latest products both domestically and internationally.

In the cutting-edge field of CT X-ray tubes, only continuous innovation and sustained investment can yield the fine wine of time. As Zhibu Technology brings more mainstream X-ray tubes to market, the future will undoubtedly raise expectations for domestically produced CT scanners.