Optimising image quality in intravenous cerebral cone beam computed tomography

Area of Science:

• Medical Imaging
• Radiology
• Diagnostic Imaging

Background:

• Intravenous cerebral Cone Beam Computed Tomography (IV CBCT) efficacy is established, but image quality assessment has been subjective.
• Quantifying factors for consistent and optimal IV CBCT image quality is crucial for clinical application.

Purpose of the Study:

• To quantitatively assess and optimize image quality parameters for IV CBCT.
• To compare image quality across different acquisition field sizes in IV CBCT.

Main Methods:

• Analyzed 79 IV CBCT patient scans (March 2021-October 2022) across 22/32, 42, and 48 cm field sizes.
• Performed quantitative analysis (Hounsfield units, SNR, CNR, noise index) and subjective diagnostic value (DV) assessment.
• Conducted phantom analysis and modulation transfer function (MTF) graphing for spatial resolution.

Main Results:

• The 42-cm protocol yielded significantly higher Hounsfield units (HU), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR), with lower noise indices.
• Greater diagnostic value (DV) was reported for the 42-cm protocol.
• Marginally improved spatial resolution was noted for the 22-cm protocol, with near-equivocal results for other sizes.

Conclusions:

• Larger acquisition field sizes (specifically 42 cm) enhance IV CBCT image quality and diagnostic value.
• This supports IV CBCT as a viable alternative to intra-arterial (IA) CBCT.
• Quantitative analysis provides a robust method for optimizing IV CBCT protocols.