High-Pitch Multienergy Coronary CT Angiography in Dual-Source Photon-Counting Detector CT Scanner at Low Iodinated...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Dual-source photon-counting detector (PCD) CT offers advanced imaging capabilities.
• Multi-energy (ME) scanning and virtual monoenergetic images (VMIs) can potentially improve image quality in coronary CT angiography (CTA).
• Reducing contrast dose in CTA is desirable to minimize patient risk.

Purpose of the Study:

• To evaluate the high-helical pitch, ME scanning mode of a clinical PCD CT.
• To assess the benefit of VMIs for low-contrast-dose coronary CTA.
• To determine if low contrast doses impact diagnostic image quality and stenosis assessment.

Main Methods:

• Coronary CTA was performed using high-pitch ME PCD-CT in two groups: low contrast dose (30 mL) and routine contrast dose (60 mL).
• Virtual monoenergetic images (VMIs) at 50 keV and 100 keV, along with 120 kV images, were reconstructed.
• Image quality metrics (CT numbers, noise, CNR) and reader confidence in stenosis assessment were evaluated.

Main Results:

• Low-contrast dose coronary CTA achieved diagnostic quality with comparable radiation doses to routine contrast dose.
• 50 keV VMIs showed significantly higher CT numbers and CNR compared to 120 kV images.
• 100 keV VMIs improved reader confidence in assessing stenosis within calcific plaques and stents, leading to CAD-RADS category changes in 9 patients.

Conclusions:

• High-pitch ME PCD-CT is effective for diagnostic coronary CTA with reduced contrast and radiation doses.
• ME VMIs significantly enhance CNR, overall image quality, and confidence in stenosis assessment, particularly in challenging cases.
• This technique offers a promising approach for optimizing coronary CTA protocols.