Aquilion 64 slice ct scanner

To test GA-AuNPs /AuNPs for CT imaging, agarose gels were used to fabricate CT phantoms. Agar strips weighing 1 g were dissolved in 50 mL DI water in a glass beaker. The solution was heated with a magnetic stirrer until it was boiling, then cooled to 100 °C for 20 min. 20% of the agar solution was combined with 1 mL of GA-AuNPs at concentrations of 55, 28, 14, and 7 ppm, and poured into 2 mL vials. The samples then were allowed to dry for two hours before being placed in the refrigerator for 24 h to harden. The same procedures are repeated for AuNPs phantoms at concentrations of (0, 6, 11, 21, 42) ppm.
A Toshiba Aquilion 64 slice CT scanner was used for the imaging in which the brightness of the photos indicates signal strength. The CT imaging parameters include the X-ray voltage of 80 kV and an anode current of 50 mA via the head window (L: 40 HU, W: 120 HU) where the scan is taken two times for each sample and the average was taken. CT images were characterized by the DICOM software that depends on the signal intensity to calculate HU as in [Eq. (1)]. FOV and slice thickness were set at 320 mm, and 3 mm, respectively. $$HU=\frac{\mu -{\mu }_{\mathit{water}}}{{\mu }_{\mathit{water}}}\times 100$$ where HU = Hounsfield Unit, μ is the linear X-ray attenuation coefficient of the substance and μ_water is the linear attenuation coefficient of water.