Ultra-high resolution computed tomography of joints: practical recommendations for acquisition protocol optimization.

Area of Science:

• Radiology
• Medical Imaging
• Computed Tomography

Background:

• Ultra-high-resolution computed tomography (CT) offers advanced imaging capabilities.
• Optimizing CT parameters is crucial for maximizing spatial resolution in musculoskeletal (MSK) imaging.

Purpose of the Study:

• To evaluate the impact of various ultra-high-resolution CT parameters on spatial resolution.
• To provide practical recommendations for optimizing MSK imaging protocols.

Main Methods:

• Evaluated parameters included field-of-view, kVp, mAs, focal spot size, slice thickness, reconstruction matrix, and iso-centering.
• Compared hybrid iterative reconstruction (HIR) and model-based iterative reconstruction (MBIR) algorithms.
• Assessed spatial resolution using CATPHAN 600 phantom and cadaveric knee imaging, analyzing line pairs per centimeter (lp/cm) and task transfer function (TTF) curves.

Main Results:

• Matrix size was the most influential factor, increasing spatial resolution up to 8 lp/cm.
• Tube output was the second most important factor, yielding a 29.6% TTF10% gain and 5 additional lp/cm.
• Reconstruction algorithm and lateral displacement also improved spatial resolution, while decreased slice thickness enhanced TTF values without affecting in-plane resolution.

Conclusions:

• The study provides actionable recommendations for optimizing spatial resolution in ultra-high-resolution CT.
• Protocol optimization can lead to improved diagnostic accuracy in musculoskeletal imaging.