CT Tubes and Maintenance: Crucial Factors in Reducing Total Cost of Ownership for CT Scanners

Introduction

When it comes to maintaining and replacing CT scanner tubes, healthcare professionals and administrators must navigate various choices that impact the Total Cost of Ownership (TCO) of their systems. A key factor in this decision is understanding the options for service maintenance and CT tube replacement, as they can significantly affect long-term costs. Our CT Scanner X-ray Tube Comparison Chart provides a clear breakdown of CT tube models, service options, and strategies to optimize TCO.

Total Cost of Ownership

Selecting a CT system goes beyond the initial purchase price—it requires an understanding of the expected TCO throughout the lifecycle of the equipment. CT systems can last for over 20 years with proper maintenance, as evidenced by older 16-slice CT scanners still in use today. However, service maintenance costs can vary widely depending on the system’s features, its accessibility to alternative service providers, and the cost of replacement parts—especially CT tubes. Systems with proprietary original equipment manufacturer (OEM) tubes often have higher TCOs, while those with alternative options from third-party manufacturers can lower ongoing expenses.

Healthcare Technology Management (HTM) and Service Options

HTM encompasses the planning, deployment, and maintenance of healthcare technology across various medical modalities, including CT scanners. Healthcare providers can manage HTM in-house or outsource it to specialists, such as independent service organizations (ISOs), OEM service organizations, or asset management companies. These organizations can negotiate blanket maintenance agreements, leveraging purchasing power to reduce service costs.

Additionally, OEMs often offer Multi-Vendor Service (MVS) divisions, where they handle the HTM functions for all equipment, regardless of brand. This service model helps streamline maintenance across different machines but can sometimes be more expensive than utilizing a dedicated third-party service provider.

Alternative Service Providers – Balancing Savings and Risk

The accompanying chart illustrates the relationship between savings and risk when choosing alternative service providers for CT system maintenance. ISOs and MVSs offer healthcare providers the best balance of savings and risk, providing cost-effective solutions without sacrificing quality. The chart demonstrates that opting for ISO or MVS services often results in a better mix of savings and risk, as opposed to relying solely on full-service OEM contracts. These alternative service models offer flexibility, competitive pricing, and reduced overall maintenance costs, making them a strong option for reducing TCO. 

Alternative OEM CT Tube Sources

Companies such as Varex, Chronos, and Dunlee manufacture replacement CT tubes that match the performance and specifications of the OEM tubes without requiring system modifications. These alternative tubes help keep the supply chain competitive, reducing costs for healthcare providers.

The presence of independent parts companies specializing in OEM part replacements also benefits HTM by making pre-owned CT tubes available at a reduced cost. However, availability can be an issue, particularly for newer systems with more specialized features.

Understanding Pre-Owned CT Tubes

Pre-owned CT tubes are typically harvested from retired but still functional systems. If your system is older and from a popular manufacturer, there is a good chance that a pre-owned tube will be available when needed. However, newer or more complex models may have limited availability for pre-owned replacements, making the timing of the need crucial.

CT Tube Lifespan Metrics

CT tubes are high-voltage vacuum diodes that will eventually fail due to heat and electrical wear. Common failures include bearing degradation or internal vacuum loss.

Manufacturers measure the expected lifespan of a tube based on usage patterns such as milliamp seconds (mAs), scan seconds, or total patient exams. Understanding these metrics can help providers anticipate when replacement will be necessary and help align tube choices with the overall TCO strategy.

• mAs (milliamp seconds): Primarily used by GE. This metric measures the total milliamperage multiplied by the amount of “on-time” in seconds that the CT system operates over time.
• Scan Seconds: Used by Toshiba/Canon, Siemens, and Philips. This measures the total time the tube has been actively scanning, regardless of clinical protocol or technique parameters.
• Total Patient Exams: Some manufacturers, like Siemens, base their end-of-life (EOL) metrics on the total number of patient exams performed, which serves as an indicator of tube usage.

These metrics help predict when a tube will reach its end of life, but they are not interchangeable across manufacturers. The relationship depends on several factors, such as tube current, rotation time, and scanning protocols.

Metal Bearings in CT Scanner X-Ray Tubes

CT scanner x-ray tubes use either ball bearings or liquid metal bearings (LMB), which affect tube performance, lifespan, and maintenance costs.

• Ball Bearings: Typically found in older or less expensive systems, these bearings have a shorter lifespan due to the degradation of the bearing coating. This can lead to increased noise and eventual rotor failure. These bearings are less expensive to manufacture but may require more frequent maintenance or replacement.
• Liquid Metal Bearings (LMB): Introduced in 1989 and first applied in fluoroscopy, LMB technology allows for continuous target rotation and quieter operation. By 2005, LMBs started appearing in higher-end CT systems. They are commonly used in high-end systems and are valued for their durability and low-noise performance. However, they come with a higher initial cost and are less widely available for replacement compared to ball bearings.

Conclusion

When looking to reduce the TCO of their CT systems, healthcare providers should carefully evaluate the types of CT tubes available, their expected lifespans, and the service options they have. Alternative and pre-owned tubes and third-party service providers can offer cost savings and flexibility, making them valuable components in managing a facility’s maintenance strategy. Providers should carefully weigh the potential savings against the risks to make the best decisions for their unique needs.

If you have any questions, please feel free to contact Radiology Oncology Systems (ROS). We’re here to assist!