Simulation of aortic peak enhancement on MDCT using a contrast material flow phantom: feasibility study

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Accurate simulation of contrast material dynamics in the aorta is crucial for CT imaging.
• Understanding time-enhancement curves is vital for interpreting CT scans, especially in cardiovascular applications.

Purpose of the Study:

• To develop a novel flow phantom that mimics aortic peak enhancement following contrast material injection during CT scans.
• To validate the developed flow phantom by comparing its time-enhancement curves with those obtained from human subjects.

Main Methods:

• A flow phantom was engineered to replicate aortic enhancement patterns.
• Various volumes and injection durations of iohexol were tested in the phantom, with some protocols including saline flush.
• Human subjects (20 patients) were divided into four groups receiving different iohexol doses and injection times, mirroring phantom protocols.
• Multi-detector CT (MDCT) scans were performed on both the phantom and patients to generate time-enhancement curves.

Main Results:

• Phantom studies showed 2-8% higher peak enhancement and 6-18% longer peak times compared to human studies.
• Time-enhancement curve shapes before peak enhancement closely matched between phantom and human studies.
• Curve shapes after peak enhancement were similar in phantom protocols with saline flush (1'-3') and corresponding human studies.
• Variability in peak enhancement within the phantom was lower than the standard deviation observed in human studies.

Conclusions:

• The developed flow phantom effectively simulates aortic peak enhancement and time-to-peak enhancement observed in human CT studies.
• The phantom's accuracy is confirmed across different contrast injection protocols, making it a valuable tool for research.
• This validated phantom can aid in optimizing contrast administration protocols and understanding CT imaging of the aorta.