Low-Dose Carotid Computed Tomography Angiography Using Pure Iterative Reconstruction.

Area of Science:

• Radiology
• Medical Imaging
• Cardiovascular Imaging

Background:

• Carotid computed tomography angiography (CTA) is crucial for diagnosing carotid artery stenosis.
• Conventional CTA protocols involve significant radiation exposure.
• Advancements in image reconstruction techniques may allow for dose reduction.

Purpose of the Study:

• To evaluate the diagnostic performance of a low-dose carotid CTA protocol.
• To compare a low-dose protocol using pure iterative reconstruction (IR) with a conventional dose protocol.
• To assess image quality and radiation dose in low-dose versus conventional dose carotid CTA.

Main Methods:

• Twenty patients underwent both low-dose and conventional dose carotid CTA.
• Low-dose CTA was reconstructed with pure IR; conventional dose CTA used 40% hybrid IR.
• Radiation dose, image noise, contrast resolution, spatial resolution, and stenosis accuracy were measured.

Main Results:

• Mean effective dose was significantly lower in the low-dose group (1.84 mSv) compared to the conventional group (3.71 mSv).
• Low-dose CTA demonstrated significantly higher subjective image noise, contrast resolution, and spatial resolution.
• Excellent agreement (Cohen κ = 0.806) was observed for carotid artery stenosis grading between the two protocols.

Conclusions:

• A low-dose carotid CTA protocol with pure IR is diagnostically comparable to conventional dose protocols.
• This low-dose protocol achieves a significant radiation dose reduction of 49.6%.
• Pure IR enables high-quality, lower-dose carotid CTA, improving patient safety.