X-ray Tubes in Computed Tomography (CT) Scanners

High Power X-ray Tubes in CT Scanners

• X-ray tubes in CT scanners are subjected to higher thermal loads compared to other diagnostic x-ray applications.
• Early CT scanners had low power levels, allowing heat dissipation during long scan times.
• Later CT scanners required high-power x-ray tubes and oil-cooled rotating anodes for efficient thermal dissipation due to shorter scan times.
• Helical CT with continuous scanner rotation introduced new demands on X-ray tubes, leading to technical advances in component design.
• Advances in tube envelope, cathode assembly, and anode assemblies (including anode rotation and target design) have enabled high-power x-ray tubes.
• Anode heat capacities have increased by up to five times, preventing the need for cooling delays during most clinical procedures.
• X-ray tubes with capacities of 5–8 million heat units are available, and heat storage capacity has increased.
• Thick graphite backing of target disks, anode diameters of 200 mm or more, and improved high-temperature rotor bearings have contributed to large heat capacities.
• Metal housings with ceramic insulators have also improved heat storage capacity.

This quiz explores the evolution of X-ray tubes in CT scanners, from low-power to high-power tubes, and the technological advancements made to dissipate heat efficiently.