[Noise Nonuniformity Dependency on Exposure Settings in Computed Tomography].

Area of Science:

• Medical Imaging Physics
• Radiological Sciences
• Image Quality Assessment

Context:

• X-ray computed tomography (CT) is a crucial diagnostic tool.
• Image noise is a significant factor affecting diagnostic accuracy in CT.
• Noise distribution in CT images is known to be nonuniform.

Purpose:

• To quantitatively evaluate the impact of varying imaging parameters on noise nonuniformity in CT images.
• To assess how tube voltage, bow-tie filter (BTF) type, and phantom size influence image noise distribution.

Summary:

• Noise nonuniformity was assessed across different tube voltages (80-135 kV), BTF types (L, M), and phantom sizes (240-400 mm).
• Noise standard deviation (SD) was consistently higher in the central image regions compared to peripheral regions.
• The noise nonuniformity index (NNI) varied significantly with imaging conditions, with phantom size having the largest impact.

Impact:

• Findings provide quantitative insights into CT image noise characteristics.
• Results can inform optimization of CT imaging protocols to improve image quality and diagnostic performance.
• Understanding noise dependence on imaging parameters is vital for consistent CT image interpretation.