Metrology for diagnostic imaging using spectral computed tomography

Each year, 60 million European citizens receive computed tomography (CT) scans, where ionising radiation in the form of X-rays is used to diagnose a range of conditions including stroke, cancer and cardiovascular disease. Recently, Spectral CT (sCT) has emerged which uses more than one X-ray energy level to derive diagnostic information. This approach can help to better distinguish between tissue types and identify disease biomarkers, allowing improved diagnosis and opening the possibility of patient-focused treatments (personalised medicine).  However, variability in sCT scanner types and a lack of standardised methods has made comparing results difficult. As sCT uses X-rays, it is also important that the radiation dose delivered to the patient is as low as reasonably achievable, but the dosimeter calibrations used in CT have not been adapted to sCT.

This project will develop characterisation methods for sCT reference phantoms which have the potential to reduce the variability between different CT scanners. Digital phantoms will also be designed and validated to support the derivation of related uncertainty budgets. The physical phantoms  will then be characterised and used to assess sCT variability between multiple clinical centres.

The work of speCTraMet and the guidance it develops will provide the first traceability for quantitative diagnostic imaging using sCT – allowing better treatment of patients whilst ensuring that their safety is paramount.