Enhancing CT imaging: Localiser radiographs' role in reducing radiation dose and optimising image quality

Objectives: To explore the role of localiser radiographs in optimising radiation dose, image quality and scan range in CT imaging. This review examined the impact of localiser selection, order and direction on radiation dose management, along with their clinical applications.
Methods: A scoping review was conducted, covering peer-reviewed studies from January 2013 to December 2023 across various databases (Medline, CINAHL, Emcare and Scopus). Thirty- six studies were included, focusing on radiation dose, image quality, patient positioning, and protocol applications. Data were extracted and analysed, with key findings regarding the influence of localiser radiographs on CT imaging processes.
Results: Localiser radiographs are crucial in managing radiation dose, with doses ranging from 0.01 to 0.9 mSv depending on their configuration, number and direction. Employing orthogonal localisers reduced radiation by up to 50%, while improper patient centring increased the dose by up to 196%. Adjusting tube current and voltage during localiser acquisition significantly lowered radiation dose without compromising image quality. Proper scan range selection using LAT localisers minimised unnecessary exposure, and emerging deep learning techniques further optimised dose reduction. Localisers also proved beneficial in guiding interventional procedures and optimising CT protocols, enhancing diagnostic accuracy and patient safety.
Conclusion: Localiser radiographs are essential for enhancing CT imaging by managing radiation dose and improving image quality. Optimal results depend on careful selection of localisers and adjustment of parameters like tube voltage and scan range. Furthermore, understanding localiser applications is crucial for ensuring patient safety and diagnostic accuracy in clinical settings.