Gadolinium-based coronary CT angiography on a clinical photon-counting-detector system: a dynamic circulating phantom...

Area of Science:

• Medical Imaging
• Radiology
• CT Technology

Background:

• Coronary computed tomography angiography (CCTA) is a key non-invasive diagnostic tool for coronary arteries.
• Intravenous contrast administration is essential for effective vessel evaluation in CCTA.
• Iodinated contrast agents are standard, but alternatives are sought for specific patient populations.

Purpose of the Study:

• To assess the feasibility of using gadolinium-based contrast agents (GBCAs) as an alternative to iodinated contrast for CCTA.
• To evaluate GBCA utility on a first-generation clinical dual-source photon-counting-detector (PCD)-CT system.

Main Methods:

• A dynamic circulating phantom with a 3D-printed thoracic aorta and coronary artery model was used.
• Gadopentetate dimeglumine was tested at 50%, 100%, 150%, and 200% of the maximum clinical dose.
• Virtual monoenergetic images (VMIs) were reconstructed from 40-100 keV on a PCD-CT, calculating contrast-to-noise ratio (CNR).

Main Results:

• The highest coronary artery attenuation (441 HU) and CNR (29.5) were achieved at 40 keV with the highest GBCA dose (200%).
• Attenuation and CNR decreased with higher keV reconstructions and lower GBCA doses.
• Sufficient attenuation (>350 HU) for diagnostic imaging was only achieved at 40-45 keV with 150% or 200% GBCA doses.

Conclusions:

• Current PCD-CT protocols and settings are inadequate for GBCA use in CCTA at clinically approved doses.
• Future PCD-CT advancements, like 4-threshold mode and multi-material decomposition, may enable GBCA k-edge imaging.
• While GBCA-enhanced coronary PCD-CT angiography is not currently feasible, GBCAs show potential for visualizing larger vessels like the aorta on PCD-CT.