Ultrasound (US) imaging, due to its capabilities of real-time imaging, portability, low cost and favorable safety, is frequently used as a diagnostic modality for the visualization of different diseases.

Mesoporous silica-coated bismuth nanoparticles (NPs) are dual-modal contrast agents that enable detection and quantification of cervical cancers at early stages using computed tomography (CT) and ultrasonography (US). Herein, the mesoporous silica-coated bismuth NPs are synthesized using a sol–gel method and conjugated with mucin-16 aptamer (MSBi@MUC16 NPs). In vitro and in vivo CT and US modalities are used to investigate the properties of these NPs in cellular and animal models. The US/CT imaging indicated that the accumulation of aptamer-armed NPs in HeLa cells was higher than in CHO cells. The targeted NPs accumulated in the overexpressing cells were considerably higher than the non-targeted NPs in both imaging modalities. In animal models, the targeted NPs effectively circulate in the blood and undergo tumor-accumulation in the HeLa tumor-bearing animal model. The concentrations of bismuth NPs correlated linearly with both CT numbers and the mean pixel intensity (MPI) values in US images. Furthermore, the measurements from inductively coupled plasma mass spectrometry (ICP-MS) closely agreed with the CT number values obtained from major organs. Based on these data, the MSBi@MUC16 NPs are proposed as high-performance hybrid contrast agents for US/CT dual-modal imaging of cervical cancer.

X-ray Computed Tomography (CT), e.g. clinical CT scanners, basically provides Linear Attenuation Coefficients (LACs) of objects under study by the means of algorithmic reconstruction of acquired views of attenuated X-ray passing through the samples in different angles around the imaged sample. Micro Computed Tomography (micro-CT) basically works the same as clinical CT. It provides volumetric information representing the inner structure of objects with a resolution in the micron range. LOTUS-inVivo is a micro-CT scanner dedicated to imaging of small animals and ex-vivo biological samples. In the present study the spatial resolution and Low Contrast Detectability (LCD) of LOTUS-inVivo scanner were evaluated using standard phantoms. We aimed to prove the capability of LOTUS-inVivo for small animal and ex-vivo biological samples imaging using the measured image quality parameters, i.e. spatial resolution and low contrast detectability. By the means of analysis of bar and LCD phantom images, the limiting resolution of LOTUS-inVivo micro-CT scanner was measured about 2.7 µm and has been shown that it’s capable of resolving sizes greater than 12.5 µm. Also, we concluded that LOTUS-inVivo is capable of discriminating tissues with 3% differences in contrast relative to the background, for 1 mm bar size. Thus, the provided technical characteristics in this study have made LOTUS-inVivo as a suitable tool for small animal imaging.

Background: The natural radiation, which comes from the environment, is one of the most important cancer risk sources. Objectives: This study aimed to measure the natural background radiations (BRs) and estimate the annual effective dose (AED), as well as the health risks in Kohgiluyeh and Boyer-Ahmad Province, Iran. Methods: background radiations for both indoors and outdoors were measured using a Geiger-Muller detector (X5C plus) in eight cities. Five points were chosen in each city for the BR measurements, and in each point, five stations were randomly selected and measured. Results: The average outdoor and indoor dose rates were obtained 136.9 ± 12.5 and 149.3 ± 19.8 nSv.h-1, respectively. The mean AEDs for adults, children, and infants were 0.17, 0.19, and 0.22 mSv.y-1 resulting from the outdoor exposure, in that order, and these values for indoor irradiation were 0.73, 0.84, and 0.94 mSv.y-1. The percentage of excess lifetime cancer risks due to indoor exposure was 4.6% for whole populations and 3% for adults. The heritable effects risk for these groups were 0.17 and 0.073%, respectively. Conclusions: The findings of the present study indicated that the average value of BR dose rates was higher than the global value. The reason can be due to the high exposure levels of hot springs, igneous rock, and high altitudes in Kohgiluyeh and Boyer-Ahmad Province.