Ultra-low-dose coronary computed tomography angiography using photon-counting detector computed tomography.

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Photon-counting detector computed tomography (PCD-CT) offers potential for significant radiation dose reduction in coronary CT angiography (CCTA).
• PCD-CT's ability to exclude electronic noise is key to maintaining image quality at lower doses.

Purpose of the Study:

• To assess radiation dose and image quality of CCTA using PCD-CT with high-pitch helical scanning and 70 kVp.
• To investigate the impact of a sharp image reconstruction kernel on image quality and stenosis assessment in ultra-low-dose CCTA.

Main Methods:

• Conducted CCTA on 40 patients using PCD-CT, high-pitch helical scanning, and 70 kVp.
• Reconstructed images with Bv64 and Bv40 kernels for analysis of image quality and stenosis.
• Collected CTDIvol and DLP data, estimating effective dose using a conversion factor.

Main Results:

• Achieved ultra-low radiation exposure: mean CTDIvol 1.72 mGy, DLP 29.1 mGy·cm, effective dose 0.41 mSv.
• Image quality was comparable between Bv64 and Bv40 kernels (P=0.75), with >95% of segments rated as good quality.
• Significant differences in stenosis scoring were observed between kernels for both non-calcified and calcified plaques (P<0.001).

Conclusions:

• PCD-CT enables ultra-low dose CCTA (29 mGy·cm DLP) with high-pitch helical scanning at 70 kVp.
• PCD-CT's noise reduction permits the use of sharp kernels, potentially enhancing stenosis evaluation without compromising image quality.
• This approach offers a promising strategy for dose reduction in CCTA while maintaining diagnostic performance.