All patients will receive pre-warmed (37 °C, 99 °F) iodinated contrast material (Ultravist; 300 mg I/ml, Bayer Healthcare, Berlin, Germany), administered automatically using a dual-head CT power injector (Stellant, Bayer).
Because a minimal applicable volume of 10 mL was required by means of a power injector (Vistron CT Injection System; Medrad, USA), contrast media for animals weighing < 3.3 kg was diluted with 0.9% saline solution until a volume of 10 mL was achieved.
Our experimental setting demonstrating two rats prior to positioning in the PET-CT scanner and homemade injector (two animals can be examined in parallel per scanning).
Randomisation to one of the two contrast medium concentrations was performed on a per day basis for logistic reasons, e.g. changing contrast material takes valuable time, and wastage of contrast medium remaining in the injector after the previous contrast-enhanced CT examination.
The physical components of a CTA include the CT scanner, intravenous cannula, access vein size, and power injector; the functional component is the patient's cardiac status.
All CT studies were scanned by a 64-detector CT system (Brilliance-64, Philips Healthcare) and a power injector was used to administer a bolus of 50 mL contrast at a 4 mL/s flow rate for CTA acquisition.
Two similar injector designs are discussed both in terms of numerical simulation and experimental results from X-ray CT scans.
