Over the past two decades, interventional neuroradiology (INR) has seen significant advances in terms of safety and radiation protection. However, the management of iodinated contrast media (ICM) administered to the patients remains problematic. There is currently no reference for applying the ALADA (As Low As Diagnostically Acceptable) principle to ICM. In this context, optimising injection parameters seems essential to limit patient risks while maintaining sufficient diagnostic quality. To achieve this, it is necessary to work on a standardised procedure: the most frequently performed being diagnostic cerebral angiography for initial assessment or follow-up of intracranial aneurysms (IA). The aim of this project is to demonstrate that the use of injection protocols with reduced flow rates and volumes would enable non-inferior results compared to the empirical protocol (used in our department) in terms of image quality for the assessment of ICA, while improving examination comfort for patients.

A Randomised controlled non-inferiority study involving a four-arm factorial design to evaluate the impact of different ICM injection strategies in diagnostic cerebral angiography. Four groups will be compared: three experimental groups evaluating reductions in injection volumes and/or flow rates, and a control group following the standard protocol currently used in Strasbourg University Hospitals. Each subject will be randomly assigned to a group, and all images will be acquired using the same protocol. By following the standard care pathway and implementing safety procedures to ensure diagnostic quality, patients will not undergo any changes to their usual care and will not run any increased risk of diagnostic error.

Inclusion Criteria:

Adult participant at the time of consent (age between 18 and 80 years old);

Scheduled diagnostic cerebral angiography as part of routine care:

• Initial assessment of the IA (suspected or detected in non-invasive imaging);
• Follow-up of one or more IAs (treated or untreated);
• Conscious and oriented participant, able to undergo the procedure under simple local anaesthesia;
• Participant able to understand the objectives of the research and provide a dated, signed informed consent form;
• Participant able to answer oral or written questions (French-speaking or understanding French);
• For women of childbearing potential: negative serum β-HCG test at the inclusion visit;
• Participant covered by a social security health insurance plan.

Exclusion Criteria:

• Emergency cerebral angiography;
• Participants with other neurovascular conditions (AVM, AVF, etc.) in addition to an IA;
• Participants with any contraindication to the use of ICM;
• Pregnancy or breastfeeding;
• Participants whose physical or psychological condition requires sedation or general anaesthesia for the procedure;
• Participants with communication or cognitive disorders; Incapable participants (subject to legal protection measures: curatorship, guardianship, judicial protection, future protection mandate, family authorization).