European Congress of Radiology, ECR, Vienna, Avusturya, 26 Şubat - 02 Mart 2025, (Özet Bildiri)
This study aimed to develop an innovative phantom for digital radiography that allows simultaneous subjective and quantitative image quality assessments. It combines subjective and quantitative image quality evaluations into one tool, unlike existing phantoms requiring multiple devices for specific assessments. High-Density Polyethylene (HDPE) was chosen for the phantom due to its tissue-equivalent density (0.95–0.97 g/cm³), cost-effectiveness, and ease of machining. The design included three modules: (1)HDPE Slabs: Simulated varying tissue thicknesses (10–25 cm) for scatter measurement, fabricated through melting, molding, and cooling. (2)Image Quality Module: Measured effective Modulation Transfer Function (eMTF), Normalized Noise Power Spectrum (eNNPS), and Detective Quantum Efficiency (eDQE), with tungsten edge tools and beam stops. (3)Contrast and SNR Module: Assessed contrast, Signal-to-Noise Ratio (SNR), and High-Contrast Spatial Resolution (HCSR) using contrast elements and a Huttner test pattern.
Monte Carlo (MC) simulations validated linear attenuation coefficients at 70, 90, and 120 kVp, optimizing parameters like transmission factor (TF) and scatter fraction (SF). Experimental validation using a digital radiography system was compared to standard phantoms (PMMA and LCD4). Quantitative metrics were calculated with OBJ IQv2 software, and Pearson correlation confirmed strong agreement between the HDPE and PMMA phantoms. The results showed strong consistency between the HDPE and PMMA phantoms. eDQE values had a high correlation (R ≥ 0.97), with less than 10% variation in contrast and SNR measurements. Spatial resolution and scatter evaluations also confirmed the HDPE phantom's reliability. The newly developed HDPE phantom offers a practical and efficient solution for digital radiography quality control. Its modular design enables simultaneous evaluation of subjective and quantitative image quality metrics, reducing the need for multiple phantoms and simplifying workflows.