Assessment of natural radioactivity in food is essential for evaluating potential radiological risks to consumers and ensuring food safety. This study investigated the activity concentrations of naturally occurring radionuclides in local and imported rice varieties marketed in the Raparin Region, Iraqi Kurdistan, and assessed the associated radiological health risks. Seventeen rice samples were collected from local markets and analyzed using an ORTEC high-purity germanium (HPGe) gamma-ray spectrometry system with 30% relative efficiency and GammaVision software. The activity concentrations ranged from 0.34 ± 0.04 to 0.54 ± 0.06 Bq kg −1 for 226 Ra, 0.77 ± 0.09 to 2.33 ± 0.24 Bq kg −1 for 232 Th, and 9.71 ± 2.89 to 109.00 ± 17.00 Bq kg −1 for 40 K, with arithmetic mean values of 0.47 ± 0.06, 1.70 ± 0.36, and 71.32 ± 29.33 Bq kg −1 , respectively. The corresponding average values of annual committed effective dose and excess lifetime cancer risk were 0.037 mSv y −1 and 0.130 × 10 −3 , respectively. All calculated radiological indices were substantially below the internationally recommended safety limits. These findings indicate that the analyzed local and imported rice varieties do not pose a significant radiological health risk and are considered safe for human consumption under normal dietary intake. The results also provide baseline data for environmental radioactivity monitoring and food safety assessment in the Kurdistan Region of Iraq.
We evaluated heterogeneous 18 F-fluorodeoxyglucose (FDG) distribution using texture features and an extended National Electrical Manufacturers Association (NEMA) phantom. Homogeneous and heterogeneous distribution was represented by spheres without or with acrylic beads (5-mm diameter). We reconstructed PET images acquired for 10 min using the Q.clear algorithm and controlled statistical noise by adjusting β values. We calculated maximum (SUV max ) and mean (SUV mean ) standardized uptake values and coefficients of variation (COV), then evaluated 22 established texture features to determine homogeneity and heterogeneity. Heterogeneous and homogeneous 18 F-FDG distribution was visualized using spherical phantoms with and without beads. The SUV max and SUV mean were underestimated by ~ 45% in heterogeneous compared with homogeneous 18 F-FDG distribution. As the β value increased, the COV for the phantoms with and without beads decreased and eventually became equivalent. When the spherical phantoms with or without beads were imaged using a β value of 100, eight textural features were associated with texture heterogeneity, and six features were associated with texture homogeneity. We extended a NEMA phantom by inserting spheres containing beads to represent heterogeneous 18 F-FDG distribution. Robust texture features were determined using the phantom to detect 18 F-FDG homogeneity and heterogeneity.
