An in-house calculator was developed to calculate the appropriate contrast dose, rather than standardly administering a 120ml dose. This study aims for a more uniform contrast enhancement in patients by means of adjusting (lowering) contrast dose to patient parameters.

Until now, CT scans in our and many other institutions are being performed with a fixed standard contrast dose specific for every protocol, independent of patient characteristics. However, many if not all patients would benefit from a contrast dose reduction, as long as image quality is not impaired. This is especially beneficial to patients with impaired renal function.

For this purpose, we researched previous literature as well as data from previously scanned patients with standard dose, to formulate a contrast dose calculation adapted to patient parameters.

An in-house calculator was developed to calculate the optimal contrast dose dependent on patient length, weight and heartrate.

A total of 60 CT-scans will be performed and retrospectively collected. Patients are randomly assigned to one of three groups : 1/ Standard dose of 120ml; 2/ Calculated dose (40-150ml) 3/ Calculated dose -50% (20-120ml). In case of reduced kidney function, patients were randomly divided between group 2 and 3 (reduced contrast dose).

Inclusion Criteria:

• Patients requiring CT-angiography of the aorta as requested by clinician
• For aneurysm detection or follow-up
• Or for dissection follow-up
• Thoraco-abdominal aorta or abdominal aorta

Exclusion Criteria:

• Contra-indications for contrast administration (severe renal impairment or adverse reactions)
• Previously endovascular repair of the aorta
• Only thoracic aorta
• No informed consent
• Contrast injection at 4cc/second not possible