Abstract.Computed tomography (CT) employs X-ray radiation to create cross-sectional images. Dual-energy CT acquisition includes the images acquired from an alternating voltage of X-ray tube: a low-and a high-peak kilovoltage. The main objective of this study is to determine the best slice thickness that reduces image noise with adequate diagnostic information using dual energy CT head protocol. The study used the ImageJ software and statistical analyses to aid the medical image analysis of dual-energy CT. In this study, ImageJ software and F-test were utilised as the combination methods to analyse DICOM CT images. They were used to investigate the effect of slice thickness on noise and visibility in dual-energy CT head protocol images. Catphan-600 phantom was scanned at different slice thickness values; .6, 1, 2,3,4,5 and 6 mm, then quantitative analyses were carried out. The DECT operated in helical mode with another fixed scan parameter values. Based on F-test statistical analyses, image noise at 0.6, 1, and 2 mm were significantly different compared to the other images acquired at slice thickness of 3, 4, 5, and 6 mm. However, no significant differences of image noise were observed at 3, 4, 5, and 6 mm. As a result, better diagnostic image value, image visibility, and lower image noise in dual-energy CT head protocol was observed at a slice thickness of 3 mm. IntroductionComputed tomography scan (CT) is a cross-sectional medical imaging technology introduced in 1972 by British engineer Godfrey Hounsfield. Computed tomography is the first radiologic modality that requires the use of computers to scan the internal organ of the body. This technology creates data depending on the different attenuation levels of the scanned area [1]. CT is classified according to the type of energy technology; the classifications are single-(SECT) and dual-energy CT (DECT). DECT provides two different attenuation levels (low and high) that construct two data sets for the same scanned area. Therefore, DECT presents more advantages to improve image quality in comparison with SECT, including the correction of the beam-hardening artifact, reduction in the radiation dose level and increase of the diagnostic content [2]. In addition, DECT developed additional techniques, such as the reduction in the number of slices and virtual non-enhanced images techniques, for reducing the radiation dose level while increasing the image quality [3].Image noise impacts the image quality in CT images. This appears as an irregular granular pattern that degrades image quality. Image noise is based on the standard deviation of pixel intensity values or CT number for uniform anatomical region. Although DECT improves image quality, it still has approximately the same or slightly lower image noise level compared with single-energy CT [4,5]. Despite the thinner slices increased the image noise, the image visibility of a small lesion has been improved by provide more diagnostic information. As a result, a balance between the change in slice

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Available online xxxKeywords: Radioactivity Soil RiceTransfer factor Physico-chemical effects a b s t r a c t Radioactivity distribution and transfer factor (TF) in plants are crucial parameters used to assess radioactive contamination in the environment and its risks to humans. In this study, the activities of 226 Ra, 232 Th, and 40 K were successfully measured via gamma-ray spectrometry on rice plant components (root, straw, husk, and grain) and on corresponding soil samples collected from paddy fields in Penang, Malaysia. Soil physicochemical characteristics (pH, citation exchange capacity, electrical conductivity, organic matter, and soil texture) were also analyzed for their estimated effects on soilegrain TF. A major fraction of the total 226 Ra and 232 Th activities measured at 47% and 57%, respectively, were concentrated in the roots, whereas only about 9% and 8% were distributed in the grains, correspondingly. 40 K activity accumulation was about 59% in the straw and 7% in the grains. Rice soilegrain TFs were observed in the ranges of (0.06e0.36) Â 10 À1 for 226 Ra, (0.04e0.14) Â 10 À1 for 232 Th, and (0.74e4.72) Â 10 À1 for 40 K. Results showed that the selected radionuclide distributions in rice are dependent on component type, and their grain concentrations are not linearly related to their soil concentrations. These findings indicated that uptake predominantly depends on soil physico-chemical characteristics.

This work examined the thermoluminescence dosimetry characteristics of Ag-doped ZnO thin films. The hydrothermal method was employed to synthesize Ag-doped ZnO thin films with variant molarity of Ag (0, 0.5, 1.0, 3.0, and 5.0 mol%). The structure, morphology, and optical characteristics were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), photoluminescence (PL), and UV–vis spectrophotometers. The thermoluminescence characteristics were examined by exposing the samples to X-ray radiation. It was obtained that the highest TL intensity for Ag-doped ZnO thin films appeared to correspond to 0.5 mol% of Ag, when the films were exposed to X-ray radiation. The results further showed that the glow curve has a single peak at 240–325 °C, with its maximum at 270 °C, which corresponded to the heating rate of 5 °C/s. The results of the annealing procedures showed the best TL response was found at 400 °C and 30 min. The dose–response revealed a good linear up to 4 Gy. The proposed sensitivity was 1.8 times higher than the TLD 100 chips. The thermal fading was recorded at 8% for 1 Gy and 20% for 4 Gy in the first hour. After 45 days of irradiation, the signal loss was recorded at 32% and 40% for the cases of 1 Gy and 4 Gy, respectively. The obtained optical fading results confirmed that all samples’ stored signals were affected by the exposure to sunlight, which decreased up to 70% after 6 h. This new dosimeter exhibits good properties for radiation measurement, given its overgrowth (in terms of the glow curve) within 30 s (similar to the TLD 100 case), simple annealing procedure, and high sensitivity (two times that of the TLD 100).

The purpose of this study is to evaluate the level of concentration of radionuclides in