X-ray Attenuation Research Articles

Theoretical and experimental analysis of the modulated phase grating X-ray interferometer.

X-ray grating interferometry allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, resulting from X-ray attenuation, refraction, and small-angle scattering, respectively. The modulated phase grating (MPG) interferometer is a recently developed grating interferometry system capable of generating a directly resolvable interference pattern using a relatively large period grating envelope function that is sampled at a pitch that is small enough that X-ray spatial coherence can be achieved by using a microfocus X-ray source or G0 grating. We present the theory of the MPG interferometry system for a 2-dimensional staggered grating, derived using Fourier optics, and we compare the theoretical predictions with experiments we have performed with a microfocus X-ray system at Pennington Biomedical Research Center, LSU. The theoretical and experimental fringe visibility is evaluated as a function of grating-to-detector distance. Additionally, quantitative experiments are performed with porous carbon and alumina compounds, and the mean normalized dark-field signal is compared with independent porosimetry measurements. Qualitative analysis of attenuation and dark-field images of a dried anchovy are shown.

Optimizing Voltage for Effective X-ray Computed Tomography Scan: A Study on Varied Soil Bulk Densities and Container Sizes

Numerous studies have highlighted the role of X-ray computed tomography (X-ray CT) in understanding root architecture. Nevertheless, setting definitive scanning parameters for diverse soils in varied container sizes remains challenging. This study investigates the influence of X-ray CT system voltage on the penetration capability in diverse soils and container sizes, focusing on two key parameters: (1) gray values, which indicate X-ray attenuation and contribute to image contrast, and (2) signal-to-noise ratio, a measure of image clarity. Five soil samples were collected from various depths within a soil profile to encompass bulk density values ranging from 1.34 to 1.84 g·cm−3 to conduct the experiment. Containers with dimensions of 6 × 6 × 6 cm³, 8 × 8 × 6 cm³, 10 × 10 × 6 cm³, 12 × 12 × 6 cm³, 14 × 14 × 6 cm³, and 16 × 16 × 6 cm³ were used. Voltage levels spanning 75 to 225 kV, in 25-kV increments, were applied to each sample. The observed gray values of the X-ray images were fitted using a logistic model of three parameters. Results showed that increasing voltage leads to enhanced penetration up to a plateau point, irrespective of soil density or container size. This plateau could potentially yield higher quality scans, given that lower voltages result in subdued gray values and reduced image contrast. Notably, it was observed that soil properties, including mineral composition, directly affect image gray values. This study established optimal voltage settings for specific soil types at fixed densities, offering valuable insights for researchers investigating soil–root interactions. Although the current findings are based on five soils, a more extensive sampling encompassing diverse soil textures and densities is necessary for a comprehensive understanding of X-ray penetration behavior across various soil types.

In Situ Crystal Growth and Fusing-Confined Engineering of Quasi-Monocrystalline Perovskite Thick Junctions for X-ray Detection and Imaging.

Metal halide perovskites exhibit great promise for utilization in X-ray detection owing to their excellent optoelectronic properties and high X-ray attenuation capabilities. However, fabricating large-area thick films for high-performance perovskite X-ray detection remains challenging. This study develops an in situ crystal growth and fusing-confined approach to prepare high-quality, large-scale perovskite quasi-monocrystalline thick junctions. The perovskite crystals are grown in situ using a highly concentrated perovskite colloidal solution in 2-methoxyethanol. Introducing methylammonium chloride enhances grain reorganization during in situ growth and fusing-confined processes, effectively reducing grain boundaries and surface defects. This allows for the preparation of quasi-monocrystalline thick junctions of large grains (>100 μm) with high crystallinity, uniform orientation, and vertical penetration across the film thickness. Additionally, the carrier mobility and lifetime of the thick junctions are significantly enhanced. The optimized MAPbI3 detectors demonstrate an X-ray sensitivity of 2.6 × 104 μC Gyair-1 cm-2 and an exceptionally low detection limit of 1 nGyair s-1. Furthermore, inspired by a honeycomb structure, these detectors realize X-ray imaging in 64 × 64 pixels through a pixelated separation design, effectively reducing the charge-sharing effect. This study offers valuable insights into the preparation of large-scale perovskite quasi-monocrystalline thick junctions for highly sensitive X-ray detection and imaging applications.

Evaluation of automatic tube current modulation in a CT scanner using a customised homogeneous phantom

Objective.The introduction of automatic tube current modulation (ATCM) has resulted in complex relationships between scanner parameters, patient body habitus, radiation dose, and image quality. ATCM adjusts tube current based on x-ray attenuation variations in the scan region, and overall patient dose depends on a combination of factors. This work aims to develop mathematical models that predict CT radiation dose and image noise in terms of attenuating diameter and all relevant scanner parameters.Approach.A homogenous phantom, equipped with the features to conduct discrete and continuous adaption tests, was developed to model ATCM in a Philips CT scanner. Scanner parameters were varied based on theoretical dose relationships, and a MATLAB script was developed to extract data from DICOM images. R statistical software was employed for data analysis, plotting, and regression modelling.Main Results.Phantom data provided the following insights: Median tube current decreased by 81% as tube potential varied from 80 kVp to 140 kVp. Doubling the DoseRight Index (DRI) from 12 to 24, at 24 cm diameter, produced a 294% increase in mA and a 46% decrease in noise. Mean mA increased by 53% whilst mean noise increased by 5.7% as helical pitch increased from 0.6 to 0.925. Changing rotation time from 0.33s to 0.75s gave a 56% reduction in mean mA and no change in image noise. Increasing detector collimation (n×T) resulted in higher tube currents and lower output image noise values, asnandTwere varied independently. Interpreting these results to apply transformations relevant to each independent variable produced models for tube current and noise with adjusted R-squared values of 0.965 and 0.912, respectively.Significance.The models developed more accurately predict radiation dose and image quality for specific patients and scanner settings. They provide imaging professionals with a practical tool to optimize scan protocols according to patient diameters and clinical objectives.

Unsupervised Denoising in Spectral CT: Multi-Dimensional U-Net for Energy Channel Regularisation

Spectral Computed Tomography (CT) is a versatile imaging technique widely utilized in industry, medicine, and scientific research. This technique allows us to observe the energy-dependent X-ray attenuation throughout an object by using Photon Counting Detector (PCD) technology. However, a major drawback of spectral CT is the increase in noise due to a lower achievable photon count when using more energy channels. This challenge often complicates quantitative material identification, which is a major application of the technology. In this study, we investigate the Noise2Inverse image denoising approach for noise removal in spectral computed tomography. Our unsupervised deep learning-based model uses a multi-dimensional U-Net paired with a block-based training approach modified for additional energy-channel regularization. We conducted experiments using two simulated spectral CT phantoms, each with a unique shape and material composition, and a real scan of a biological sample containing a characteristic K-edge. orangeMeasuring the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) for the simulated data and the contrast-to-noise ratio (CNR) for the real-world data, our approach not only outperforms previously used methods—namely the unsupervised Low2High method and the total variation-constrained iterative reconstruction method—but also does not require complex parameter tuning.

AdaTL1: an adaptive non-convex sparse solver with applications to CT reconstruction and image denoising

Abstract Sparsity-promoting optimization techniques have, in recent years, gained prominence due to the availability of efficient solvers and their capability to efficiently use inherent duplication present in underlying data. In clinical Tomography, a faithful reconstruction of the cross-section of an object or image from a reduced set of x-ray attenuation samples attains importance. Though sparsity methods in Computed Tomography (CT) have already been well attended to, there is still a need for newer ideas that accommodate the highly coherent nature of the sub-sampled Radon matrix and incorporate adaptive information into the recovery process. To this end, we propose an adaptive transformed L 1 minimization (referred to as AdaTL 1), which being a non-convex problem is a generalization of transformed L 1 minimization. We discuss the recovery guarantees of AdaTL 1 and propose its solver. Further, we compare and contrast its performance against the known methods in the reconstruction of CT as well as the denoising of images.

Multifunctional gold nanoparticles for cancer theranostics.

The diagnosis and treatment of cancer can often be challenging requiring more attractive options. Some types of cancers are more aggressive than others and symptoms for many cancers are subtle, especially in the early stages. Nanotechnology provides high sensitivity, specificity and multimodal capability for cancer detection, treatment and monitoring. In particular, metal nanoparticles (NPs) such as gold nanoparticles (AuNPs) are attractive nanosystems for researchers interested in bioimaging and therapy. The size, shape and surface of AuNPs can be modified for improving targeting and accumulation in cancer cells, for example through introduction of ligands and surface charge. The interactions of AuNPs with electromagnetic radiation (e.g., visible-near-infrared, X-rays) can be used for photothermal therapy and radiation therapy, through heat generated from light absorption and emission of Auger electrons, respectively. The subsequent expansion and high X-ray attenuation from AuNPs can be used for enhancing contrast for tumor detection (e.g., using photoacoustic, computed tomography imaging). Multi-functionality can be further extended through covalent/non-covalent functionalization, for loading additional imaging/therapeutic molecules for combination therapy and multimodal imaging. In order to cover the important aspects for designing and using AuNPs for cancer theranostics, this review focuses on the synthesis, functionalization and characterization methods that are important for AuNPs, and presents their unique properties and different applications in cancer theranostics.

Investigating radiation shielding parameters for X-ray attenuation at various energies in locally produced ceramic materials used in Saudi Arabia

To assess shielding effectiveness against X-rays, a number of locally collected ceramic samples were obtained from the Kingdom of Saudi Arabia. Based on elemental analysis, all of the ceramic samples have a density in the range of 1.68–1.85 g/cm3, with the highest proportions of O, Si, C, and Al atoms and the lowest amounts of Na, Mg, K, Ca, Ti, and Fe. The 320 kV X-ray source (Gulmay Limited, Byfleet, UK) was used to assess the attenuation properties of the ceramic samples. An Exradin A4 ionization chamber (Standard Imaging, Middleton, USA) connected to a UNIDOS electrometer (PTW, Freiburg, Germany) in the control room was used to detect the attenuation properties. Several X-ray attenuation coefficients are evaluated at different X-ray energies in the range of 40–150 kV in this study. These include the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP). The ability of any ceramic sample under investigation to shield radiation at low X-ray energy is indicated by the theoretical and experimental values of LAC. The potential applications of these easily accessible, reasonably priced ceramic materials for radiation protection in X-ray labs and low-energy X-ray shielding in a variety of fields have been shown by this investigation.

Wafer-Sized CsPbBr3/CsPbCl3 Heterojunction: Breaking the Trade-Off between Sensitivity and Dark Current for Efficient X-ray Detector.

Polycrystalline lead halide perovskite finds promising use in fabricating X-ray detectors with a large lateral size, adjustable thickness, and diverse synthesis processes. However, a large dark current hinders its development for weak signal detection. Herein, we propose a multistep pressing strategy for manufacturing a CsPbBr3/CsPbCl3 heterojunction wafer for a reduced dark current X-ray detector, and the device keeps a high sensitivity value after the insertion of a barrier by heterojunction; thus, the trade-off between sensitivity and dark current can be broken. The X-ray detector with a metal-semiconductor-metal structure yields a sensitivity of 6.32 × 104 μC Gyair-1 cm-2 at a bias of 12 V, a 1/f noise of 1.02 × 10-13 A/Hz-1/2, and a detection limit of 66.58 nGy s-1. These performance parameters are considerably better than those of a similar X-ray detector based on the single-structure wafer. The improved device performance of the heterostructure X-ray detector is ascribed to the suppressed carrier recombination, enhanced carrier transportation of the heterojunction, and strong X-ray attenuation of the CsPbCl3 layer. The pixel array device is further used in imaging applications. Hence, this study provides an efficient strategy for fabricating heterostructure polycrystalline lead halide perovskite wafers for use in high-performance wafer-based X-ray detectors.

Shielding characteristics of a new epoxy resin reinforced by PbO nanoparticles and PbO micro for protection against X-ray and investigation of their cytotoxicity effects and photocatalytic activity

In this research, for the first time, lead oxide nanoparticles (PbO-NPs) were synthesized using Trigonella feonumgraecum plant seeds as a stabilizer and Pb (NO3)2 salt as lead precursor. The results of the XRD pattern displayed the synthesized NPs have an orthorhombic crystalline structure. According to FESEM images, the NPs had a mean size of about 18.62 nm with a spherical morphology. Also, the cytotoxicity of NPs was evaluated on the Hep G2 cancer cell line, and the IC50 value was reported as 267.07 μg/mL. Next, the photocatalytic performance of the synthesized PbO-NPs was investigated for removing methylene orange (MO) pigment under UVA light, which led to the destruction of about 94% after 120 min. Finally, to investigate the protective property of PbO-NPs against X-ray, a polymer nanocomposite of epoxy resin/PbO-NPs was prepared with different weight percentages. In the same way, other samples were also prepared, and then their ability to attenuate X-ray was studied with an X-ray tube with a voltage of 52 kV for the palm and 80 kV for the thigh of an average person, respectively. The measurement results show that with the increasing weight percentage of the fillers, the samples' linear and mass attenuation coefficient increases, which means an increase in the efficiency of the samples in X-ray attenuation. Generally, epoxy resin/PbO-NPs samples show a better effect than other samples. Therefore, these types of shields can attract more attention due to their lightness, cost-effectiveness, and far fewer environmental hazards than common lead shields.

Classification of Electronic Waste Components through X-ray and Neutron-Based Imaging Techniques.

In modern society, the amount of e-waste is growing year by year. Waste electronic items are complex, highly heterogeneous systems, containing organic material as well as several exotic, valuable, toxic, mostly metallic elements. In this study, the potential of X-ray and neutron radiography to reveal the inner structure of various complex e-waste was investigated. The images obtained using the two techniques were evaluated together to investigate the possibility of a more efficient segmentation of the individual components. The advantages and limitations of the two methods were identified for the studied waste types. X-ray radiography was found to be preferable for the identification of small metallic parts and for revealing the internal structure of e-waste with thick plastic coatings. Neutron radiography allowed for the identification of several components that did not provide sufficient contrast with X-ray imaging due to their similar X-ray attenuation compared to their surroundings. The combination of the two methods opens up new opportunities and could provide much more effective segmentation than either method alone.

Ion Leakage Current Control for Polycrystalline Metal Halide Perovskite Direct X-ray Detectors.

Metal halide perovskites have emerged as promising materials for X-ray detection due to their high X-ray attenuation coefficients, defect tolerance, and suitability for large-area, low-temperature fabrication. However, the intrinsic high ion conductivity of these materials presents challenges, such as high dark current density and current drift, which impair the stability and sensitivity of perovskite X-ray detectors. This study introduces an approach to mitigating these issues by incorporating 2,2,3,3,3-pentafluoropropylamine hydrochloride (PFH) into polycrystalline MAPbI3-xClx films using a one-step blade-coating method. PFH aggregates at grain boundaries, raising local vacuum energy levels and passivating surface defects, thereby reducing ion conductivity without affecting electron conductivity. As a result, this approach significantly reduces the dark current and enhances sensitivity, achieving a low detection limit of 14.7 nGyair/s. Additionally, it improves signal stability, consistency, and response speed of the detector. These findings suggest that PFH is a promising additive for advancing the performance and practical application of polycrystalline metal halide perovskite-based X-ray detectors.

Robust quantitative X-ray phase diagnostic for carbon composite characterisation in the context of lightning induced risk

Getting complementary physical information from a single image acquisition is particularly valuable for materials analysis. Grating based X-ray Phase Contrast Imaging (XPCI) methods allow decoupling attenuation, phase and scattering information. However, the phase and scattering extraction processes can easily suffer from artefacts, which is detrimental to implement this imaging technique in societal applications. In this paper, we demonstrate that grating based XPCI can provide a robust phase measurement in complex materials such as damaged composites. The technique allows the phase to be analysed using a self-assessment method that first identifies the artefacts from the imaging setup, and then can be used as an indicator to interpret the signal from a material. We focus on carbon fibre reinforced polymers which we subjected to laboratory-controlled lightning strikes. We evidence that the combined information from phase and attenuation allow identifying the type of defect induced by the lightning current. The phase information is converted into relative mass density variation within the sample and depicts areas with a loss in density up to 40%. We ensure that these results are valid by comparing them with an X-ray attenuation contrast tomographic reconstruction.

Micro computed tomography analysis of barley during the first 24 hours of germination

BackgroundGrains make up a large proportion of both human and animal diets. With threats to food production, such as climate change, growing sustainable and successful crops is essential to food security in the future. Germination is one of the most important stages in a plant’s lifecycle and is key to the success of the resulting plant as the grain undergoes morphological changes and the development of specific organs. Micro-computed tomography is a non-destructive imaging technique based on the differing x-ray attenuations of materials which we have applied for the accurate analysis of grain morphology during the germination phase.ResultsMicro Computed Tomography conditions and parameters were tested to establish an optimal protocol for the 3-dimensional analysis of barley grains. When comparing optimal scanning conditions, it was established that no filter, 0.4 degrees rotation step, 5 average frames, and 2016 × 1344 camera binning is optimal for imaging germinating grains. It was determined that the optimal protocol for scanning during the germination timeline was to scan individual grains at 0 h after imbibition (HAI) and then the same grain again at set time points (1, 3, 6, 24 HAI) to avoid any negative effects from X-ray radiation or disruption to growing conditions.ConclusionHere we sought to develop a method for the accurate analysis of grain morphology without the negative effects of possible radiation exposure. Several factors have been considered, such as the scanning conditions, reconstruction, and possible effects of X-ray radiation on the growth rate of the grains. The parameters chosen in this study give effective and reliable results for the 3-dimensional analysis of macro structures within barley grains while causing minimal disruption to grain development.

PEGylated Pemetrexed and PolyNIPAM Decorated Gold Nanoparticles: A Biocompatible and Highly Stable CT Contrast Agent for Cancer Imaging.

This study describes a multifunctional nanoparticle platform for targeted CT imaging and therapy of cancers. Pemetrexed (conjugated with polyethylene glycol, MW 2000 Da) and polyNIPAM (PEGylated) were designed for targeted delivery to folate receptors and thermally ablated tumors, respectively. These moieties were coated on gold nanoparticles (7 and 30 nm), and the prepared compounds were characterized using 1H NMR, FT-IR, CHNS, DLS, TEM, TGA, and UV-vis. The resulting agents exhibited 2-4 times higher X-ray attenuation compared to Visipaque and demonstrated specific accumulation in tumor tissue (4T1 xenograft model) 90 min after injection in mice. The nanoparticles displayed anticancer activity against 4T1 and MDA-MB-231 breast cancer cells (IC50: 182.87 and 206.18 μg/mL) and good biocompatibility. Importantly, the platform showed excellent stability over a year and at pH 2-12 and temperature range of -78 to 40 °C, and a water-dichloromethane extraction method was optimized for efficient purification, facilitating large-scale production.

Fluoride Hafnium/Zirconium-Softened Nanoprobes for Near-Infrared-IIb and CT Dual-Mode Bioimaging.

Fluoride-based lanthanide-doped nanoparticles (LDNPs) featuring second near-infrared (NIR-II, 1000-1700 nm) downconversion emission for bioimaging have attracted extensive attention. However, conventional LDNPs cannot be degraded and eliminated from organisms because of an inert lattice, which obstructs bioimaging applications. Herein, the core-shell LDNPs of Na3HfF7:Yb,Er@CaF2:Ce,Zr(Hf) [labeled as Zr(Hf)Ce-HC] with pH-selective and tunable degradability were synthesized for dual-modal bioimaging. Notably, the "softening" lattice of the Na3HfF7 matrix and different Zr4+(Hf4+) doping amounts in the shell enable Zr(Hf)Ce-HC with acidity-dependent and tunable degradability. After coating of an optimized Ce3+-doped CaF2:Zr shell, the near-infrared-IIb (NIR-IIb, 1500-1700 nm) luminescence intensity of ZrCe-HC is enhanced by 5.2 times compared with that of Na3HfF7:Yb,Er. The Hf element with high X-ray attenuation allows ZrCe-HC as the contrast agent for computed tomography (CT) bioimaging. The modification of oxidized sodium alginate endows ZrCe-HC with satisfying biocompatibility for NIR-IIb/CT dual-modal bioimaging. These findings would benefit the bioimaging applications of degradable fluoride-based LDNPs.

Multiphase distribution in partly saturated hierarchical nonwoven fibre networks under applied load using X-ray computed tomography

In many industrial applications, nonwoven fibre networks are facilitated to operate under partly saturated conditions, allowing for filtration, liquid absorption and liquid transport. Resolving the governing liquid distribution in loaded polyamide-6 (PA6) fibre networks using X-ray computed micro-tomography is a challenge due to the similar X-ray attenuation coefficients of water and PA6 and limitations in using background subtraction techniques if the network is deformed, which will be the case if subjected to compression. In this work, we developed a method using a potassium iodide solution in water to enhance the liquid’s attenuation coefficient without modifying the water’s rheological properties. Therefore, we studied the evolving liquid distribution in loaded and partly saturated PA6 fibre networks on the microscale. Increasing the external load applied to the network, we observed an exponential decrease in air content while the liquid content was constant, increasing the overall saturation with increasing network strain. Furthermore, the microstructural properties created by the punch-needle process in the manufacturing of the network significantly influenced the out-of-plane liquid distribution. The method has been proven helpful in understanding the results of adaptions in both the fibre network design and manufacturing process, allowing for investigating the resulting liquid distribution on a microscale.

Gram-Scale Synthesis of Renal-Clearable Tantalum Nanodots with High Water Solubility for Computed Tomography Imaging In Vivo.

Tantalum (Ta) emerges as a promising element for advanced computed tomography (CT) imaging probes owing to its high X-ray attenuation coefficient and excellent biocompatibility. Nevertheless, the synthesis of renally clear Ta-based imaging probes through simple methods remains a significant challenge. Herein, we introduce a simple and gram-scale approach for the synthesis of renal-clearable Ta nanodots with high water solubility for CT imaging in vivo. The Ta nanodots, coordination polymers, are fabricated via coordination reactions involving Ta(OH)5, citric acid (CA), and hydrogen peroxide. The Ta nanodots exhibit an ultrasmall hydrodynamic diameter (2.8 nm), high water solubility (1.88 g/mL, 688 mg Ta/mL), superior X-ray absorption capacity, gram-scale production capability (>10 g in lab synthesis), renal-clearable ability, and good biocompatibility. The Ta nanodots possess superior CT imaging efficacy across diverse tube voltages, enabling highly sensitive gastrointestinal CT imaging, renal CT imaging, and CT angiography (CTA). Moreover, Ta nanodots maintain robust CT imaging capabilities even at high X-ray energies, and Ta nanodots-based spectral CT achieves metallic artifacts-minimized CTA. The proposed Ta nanodots present substantial potential as a potent CT imaging probe for diagnosing various diseases.

Toward the Clinical Translation of Safe Intravenous Long Circulating Iodinated Lipid Nanoemulsion Contrast Agents for CT Imaging.

Current clinical small molecule x-ray CT agents are effective but pose risks such as nephrotoxicity, short blood circulation time, limiting scan durations, potential thyroid impact, and immune responses. These challenges drive the development of kidney-safe x-ray nanoparticle (NP)-based contrast agents (CAs), though translation to clinical practice is hindered by chemical complexities and potential toxicity. We have engineered an intravenous, injectable, and safe blood pool NP-based CT CAs at a clinical-equivalent dose of ∼300 mgI/kg (∼2 mL/kg), ideal for vascular and hepatic imaging which are limited by clinical agents. Our iodinated lipid nanodroplet emulsions (ILNEs) contrast agent offers high x-ray attenuation thus improved contrast enhancement, extended stability, and exceptional batch-to-batch consistency. It also boasts a straightforward and scalable manufacturing process with minimal protein interaction, prolonged blood residency (∼4h), and hepatic clearance within 3 days, avoiding nephrotoxicity. Studies in vitro, in mice, and 16.6kg porcine animal model studies confirm its safety, cytocompatibility, and absence of tissue damage. Blood, and thyroid-stimulating hormone (TSH) analyses, and kidney and liver function tests, also support further toxicity evaluations for clinical translation.

Radiation shielding potential of cellulose acetate-CdO-ZnO polymer composites in comparison with concrete and gypsum

Radiation shielding using polymer composites is becoming more attractive because of their ease of production, lightness, ruggedness and availability. In this work, linear attenuation coefficient (LAC) and tenth value layer (TVL) of Cellulose Acetate - CdO - ZnO Polymer Composites of different concentrations of CdO and ZnO denoted as PB1, PB2 and PB3 were investigated against concrete and gypsum. Cellulose Acetate-CdO-ZnO Polymer Composites were prepared using the open mold cast technique and have been investigated for x-rays shielding ability. Cellulose acetate is a biodegradable good matrix, while CdO and ZnO are good fillers for absorbing x-rays in the diagnostic energy range. Scanning Electron Microscopy (SEM) technique was used to observe the uniform dispersal of fillers within the matrix. X-rays attenuation coefficients were calculated by XCOM computer code for all the samples using the average energies commonly used in diagnostic radiology practice - 20 keV, 30 keV, 40 keV and 60 keV. The SEM confirmed the dispersal of the fillers (CdO and ZnO) within the matrix. The result of this investigation showed that all the polymer composites (PB1, PB2 and PB3) have higher LACs and lower TVLs over gypsum and concrete at 20 keV, 30 keV, 40 keV and 60 keV. Tenth Value Layers (TVLs) of all the polymer composites is less than 1 cm at 20 keV, 30 keV and 40 keV.