Accuracy of electron density, effective atomic number, and iodine concentration determination with a dual‐layer dual‐energy computed tomography system

PURPOSE: ), and iodine concentration, directed for more accurate radiation therapy planning, with a new dual-layer dual-energy computed tomography (DL-DECT) system. The dependence of the accuracy of these values on the scan and reconstruction parameters, as well as on the phantom size, was also examined. METHODS: for the insert materials were derived from the chemical compositions provided by the vendors. The nominal scan condition for the accuracy measurements was 120 kVp, 20 mGy CTDIvol, 0.812 pitch, 16 × 0.625 mm collimation, and 0.33-second gantry rotation. RESULTS: scatter plot, even at the lowest concentrations (2 mg/mL for iodine and 50 mg/mL for calcium). CONCLUSIONS: determination, and iodine quantitation derived from DL-DECT was demonstrated with phantom measurements. The accuracies were not sensitive to scan and reconstruction parameters, namely tube potential, dose, rotation time, and spectral reconstruction level, especially in the case of electron density.