Spectral quantification in different lumen diameters for cardiovascular applications.

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Dual-source photon-counting CT (PCCT) combines high spatial resolution and spectral imaging, beneficial for visualizing small vessels like coronary arteries.
• Previous studies confirmed PCCT's high spatial resolution and quantification accuracy, but the impact of lumen size on spectral quantification remained unevaluated.

Purpose of the Study:

• To evaluate the effect of lumen size on spectral quantification accuracy in dual-source photon-counting CT.
• To assess how varying phantom sizes, iodine concentrations, and radiation doses influence spectral quantification in PCCT.

Main Methods:

• Phantoms with internal diameters from 4 to 12 mm were created to simulate coronary arteries.
• Phantoms were filled with iodine solutions (2, 5, 10 mg/mL) and scanned using PCCT.
• Virtual monoenergetic images (VMI) at 70 keV, iodine density maps, and virtual non-contrast (VNC) maps were analyzed.

Main Results:

• Consistent spectral quantification was achieved for lumen diameters greater than 6 mm across all phantom sizes.
• VMI 70 keV showed minimal deviation (±15, ±12, ±4) at larger diameters (12 mm) for different iodine concentrations.
• Significant deviations in VMI 70 keV, iodine density maps, and VNC were observed at a 4 mm lumen diameter, particularly with larger phantoms.

Conclusions:

• Dual-source photon-counting CT demonstrates reliable spectral quantification for coronary artery phantoms with lumen diameters exceeding 6 mm.
• The high spatial resolution and quantification accuracy of PCCT show synergy, supporting the use of quantitative metrics in cardiac imaging.
• Further development of quantitative applications in diagnostic cardiac imaging is anticipated due to these findings.