[Evaluation for Resolution Property of CT Image with Half-reconstruction Algorithm].

Area of Science:

• Medical Imaging
• Radiology
• Image Reconstruction

Background:

• Computed tomography (CT) is a crucial diagnostic tool.
• Image reconstruction algorithms impact diagnostic quality.
• Assessing resolution properties is vital for CT performance evaluation.

Purpose of the Study:

• To evaluate the XY-plane resolution of half-reconstruction CT images.
• To compare the resolution of half-reconstruction CT with full-reconstruction CT.
• To measure 360° multi-directional modulation transfer functions (MTFs) for resolution assessment.

Main Methods:

• Measured 360° multi-directional MTFs using a wire method at 15° intervals.
• Acquired MTFs for half-reconstruction CT at off-center positions (±100 mm on X and Y axes).
• Compared MTFs between half- and full-reconstruction CT images, including variations with X-ray tube positions.

Main Results:

• Significant differences in MTFs were observed between tangential and radial directions for half-reconstruction CT.
• Resolution property dependencies on position and direction were similar for both half- and full-reconstruction CT.
• MTFs at X+100 mm were higher/lower for half-reconstruction CT depending on the X-ray tube's projection dataset side (+X/-X).

Conclusions:

• Half-reconstruction CT images exhibit comparable XY-plane resolution to full-reconstruction CT images.
• The resolution of half-reconstruction CT, specifically MTF in the tangential direction, is influenced by the X-ray tube position in the projection dataset.