Understanding automated dose control in dynamic X-ray imaging systems

Learning Objectives: To understand the inner workings of the automatic dose rate control (ADRC) which controls radiographic factors during interventional procedures. This understanding will help clinicians utilise the X-ray system in the most optimal manner – to maximise image quality with the lowest possible radiation dose to both the patient and staff. Background: Modern interventional X-ray systems control X-ray output via an automated closed-loop control system. The ADRC makes systems straightforward to use in clinical practice, maintaining acceptable patient doses whilst providing adequate image quality and ensuring the X-ray tube and generator are operated within their specified working parameters. This poster aims to benefit both clinical staff and hospital physicists by providing information on ADRC operation. Procedure Details: The different ADRC operational modes (fluoroscopy, cine and digital subtraction angiography) will be described, with details provided on how differences in patient size, imaging geometry, and user actions affect X-ray output. The constraints that the ADRC operates under will be explained, including X-ray tube limits and legal radiation dose limits. The complex relationship between patient dose and image quality will be described with reference to how the ADRC must balance the two. Data from simulations and system measurements will be used to illustrate the description. Conclusion: An understanding of ADRC operating mechanisms by clinical users facilitates improved X-ray system usage, which can lead to lower radiation doses and improved image quality. It also allows improved clinical support and equipment testing by physicists.