Achieving optimal image quality in computed tomography (CT) is essential for accurate diagnosis. This study explores the relationship between objective and subjective image quality, using the detectability index (d^) as a quantitative performance metric. A 3D-printed anthropomorphic abdominal phantom was used to assess how variations in tube voltage, current, slice thickness, and reconstruction kernel affect image quality. Signal-to-noise ratio, contrast-to-noise ratio, and edge sharpness were evaluated alongside radiologist assessments. A strong correlation between d^ and subjective quality confirmed d^ as a reliable predictor of visual image perception. Multiple linear regression identified d^, object size, and the peak spatial frequency of the noise power spectrum as independent predictors of perceived quality. These results support the integration of d^ into routine CT image quality evaluation, helping to align technical image parameters with clinical expectations and improve protocol optimization.
Bečirčić et al. (Tue,) studied this question.