X-ray radiography of HPGe detectors for Monte Carlo simulations

The results of the development of a radiographic installation that allows to control the size of the internal elements of HPGe detectors' cryostats for simulation by Monte Carlo method, are presented. Calibration and assessment of image quality value of the developed radiographic installation were carried out in accordance with ISO Standards 19232-1 and 19232-5. Simulation of the HPGe detector's registration efficiency in the range of 50 keV-3 MeV with the MCC-MT program showed that the discrepancy between the calculated and experimental results when adjusting the detector model using radiological measurement data does not exceed 3% in geometry for point sources and 5% for the Eu-152 source in the Marinelli beaker geometry.

Transfer learning-based ensemble convolutional neural network for accelerated diagnosis of foot fractures

The complex shape of the foot, consisting of 26 bones, variable ligaments, tendons, and muscles leads to misdiagnosis of foot fractures. Despite the introduction of artificial intelligence (AI) to diagnose fractures, the accuracy of foot fracture diagnosis is lower than that of conventional methods. We developed an AI assistant system that assists with consistent diagnosis and helps interns or non-experts improve their diagnosis of foot fractures, and compared the effectiveness of the AI assistance on various groups with different proficiency. Contrast-limited adaptive histogram equalization was used to improve the visibility of original radiographs and data augmentation was applied to prevent overfitting. Preprocessed radiographs were fed to an ensemble model of a transfer learning-based convolutional neural network (CNN) that was developed for foot fracture detection with three models: InceptionResNetV2, MobilenetV1, and ResNet152V2. After training the model, score class activation mapping was applied to visualize the fracture based on the model prediction. The prediction result was evaluated by the receiver operating characteristic (ROC) curve and its area under the curve (AUC), and the F1-Score. Regarding the test set, the ensemble model exhibited better classification ability (F1-Score: 0.837, AUC: 0.95, Accuracy: 86.1%) than other single models that showed an accuracy of 82.4%. With AI assistance for the orthopedic fellow, resident, intern, and student group, the accuracy of each group improved by 3.75%, 7.25%, 6.25%, and 7% respectively and diagnosis time was reduced by 21.9%, 14.7%, 24.4%, and 34.6% respectively.

Visualizing fluid transport inside orally disintegrating tablets and changes in tablets using real-time X-ray radiography and X-ray computed tomography

OBJECTIVE

To investigate the disintegration of wet- and dry-compressed orally disintegrating (OD) tablets, with synchrotron radiation as the X-ray source.

SIGNIFICANCE

Pharmaceutical tablets are vital for treatment of various diseases. Therefore, they are constantly developed to ensure desirable characteristics. In particular, OD tablets need to disintegrate immediately after absorbing saliva. How these tablets absorb saliva is key to enhancing rapid product development. Recently, absorption processes have been investigated using various non-invasive techniques, including X-ray radiography and X-ray computed tomography. However, X-ray radiography studies on how water without a contrast agent is absorbed, moves, and causes a tablet to swell are scarce. Use of a contrast agent is associated with some shortcomings, including complex data analysis in some instances, alterations in the viscosity of water, and potential influence on fluid transport inside the tablet, thus possibly affecting the disintegration process.

METHODS

Real-time X-ray radiography was used to monitor the disintegration of various tablets, while X-ray computed tomography and software were used to create 3D images.

RESULTS

We demonstrated how pure water penetrated the wet-compressed tablet faster than inside the dry-compressed tablet, and how the latter swelled more. X-ray computed tomography showed the presence of voids in the tablets following water absorption.

CONCLUSION

Our methods are promising for non-destructive fluid absorption and transport investigations inside OD tablets.

Dental Diagnosis and Treatment Assessments: Between X-rays Radiography and Optical Coherence Tomography

A correct diagnosis in dental medicine is typically provided only after clinical and radiological evaluations. They are also required for treatment assessments. The aim of this study is to establish the boundaries from which a modern, although established, imaging technique, Optical Coherence Tomography (OCT), is more suitable than the common X-ray radiography to assess dental issues and treatments. The most common methods for daily-basis clinical imaging are utilized in this study for extracted teeth (but also for other dental samples and materials), i.e., panoramic, intraoral radiography, and three-dimensional (3D) cone beam computed tomography (CBCT). The advantages of using OCT as an imaging method in dentistry are discussed, with a focus on its superior image resolution. Drawbacks related to its limited penetration depth and Field-of-View (FOV) are pointed out. High-quality radiological investigations are performed, measurements are done, and data collected. The same teeth and samples are also imaged (mostly) with an in-house developed Swept Source (SS)-OCT system, Master-Slave enhanced. Some of the OCT investigations employed two other in-house developed OCT systems, Spectral Domain (SD) and Time Domain (TD). Dedicated toolbars from Romexis software (Planmeca, Helsinki, Finland) are used to perform measurements using both radiography and OCT. Clinical conclusions are drawn from the investigations. Upsides and downsides of the two medical imaging techniques are concluded for each type of considered diagnosis. For treatment assessments, it is concluded that OCT is more appropriate than radiography in all applications, except bone-related investigations and periodontitis that demand data from higher-penetration depths than possible with the current level of OCT technology.

Non-Invasive Approaches for the Evaluation of the Functionalization of Melamine Foams with In-Situ Synthesized Silver Nanoparticles

The use of polymeric nanocomposites has arisen as a promising solution to take advantage of the properties of nanoparticles (NPs) in diverse applications (e.g., water treatment, catalysis), while overcoming the drawbacks of free-standing nanoparticles (e.g., aggregation or accidental release). In most of the cases, the amount and size of the NPs will affect the stability of the composite as well as their performance. Therefore, a detailed characterization of the NPs present on the nanocomposites, including their quantification, is of vital importance for the optimization of these systems. However, the determination of the NPs load is often carried out by destructive techniques such as TGA or ICP-OES, the development of non-invasive approaches to that aim being necessary. In this work, the amount of silver NPs synthesized directly on the surface of melamine (ME) foams is studied using two non-invasive approaches: colorimetry and X-ray radiography. The obtained results show that the amount of silver NPs can be successfully determined from the luminosity and global color changes of the surface of the foams, as well as from the X-ray attenuance.

In situ diagnostic analysis of the XVIII century Madonna della Lettera panel painting (Messina, Italy)

The scientific investigation of the techniques employed by the artist, such as composition of the paints, color palette, and painting style represents a fundamental pre-requisite in order to develop proper conservation and restoration strategies. In this context, the combined use of non-destructive, non-invasive in situ image and chemical analyses was here successfully employed for the investigation of the XVIII century Madonna della Lettera panel painting from the ancient Basilian abbey of Santa Maria di Bordonaro in Messina (Italy). The used techniques were visible, infrared (IR) and false-color infrared (FCIR) photography, X-ray radiography, X-ray fluorescence (XRF) and Raman spectroscopy. The goal was to obtain accurate information on materials and techniques originally used and possible later interventions, with particular regard to the nature of the painting materials. From the results, details of the artwork useful for restoration and conservation procedures were revealed. The identification of most of the artist's palette was also achieved: Prussian blue for blue color, lead white for white, umber for the brown, cinnabar for the red, and carbon black for the black color. The composition of different preparatory substrates was also investigated. The obtained results, other than constituting a crucial step for future restoration works, can be at the same time useful for the dating of the painting, that does not report the date and the artist's signature.

Light Weight, Easy Formable and Non-ToxicPolymer-Based Composites for Hard X-rayShielding: A Theoretical and Experimental Study

Composite lightweight materials for X-ray shielding applications were studied anddeveloped with the goal of replacing traditional screens made of lead and steel, with innovativematerials with similar shielding properties, but lighter, more easily formed and workable, with lowerimpact on the environment and reduced toxicity for human health. New epoxy-based compositesadditivated with barium sulfate and bismuth oxide were designed through simulations performedwith software based on Geant4. Then, they were prepared and characterized using differenttechniques starting from digital radiography in order to test the radiopacity of the composites,in comparison with traditional materials. The lower environmental impact and toxicity of theseinnovative screens were quantified by Life Cycle Assessment (LCA) calculation based on the ecoinventdatabase, within the openLCA framework. Optimized mixtures are (i) 20% epoxy/60% bismuthoxide/20% barite, which guarantees the best performance in X-ray shielding, largely overcomingsteel, but higher in costs and a weight reduction of circa 60%; (ii) 20% epoxy/40% bismuth oxide/40%barite which has slightly lower performances in shielding, but it is lighter and cheaper than thefirst one and (iii) the 20% epoxy/20% bismuth oxide/60% barite which is the cheapest material, stillmaintaining the X-ray shielding of steel. Depending on the cost/efficiency request of the specificapplication (industrial ra.

X-ray absorption as an alternative method to determine the exhausting degree of activated carbon layers in water treatment system for medical services

Analytical methods based on X-Ray radiation proved to be reliable and sensitive techniques to study activated carbons (ACs). An X-Ray absorption analysis based on digital radiographic images (XRA) is applied for the determination of the exhaustion degree of granular activated carbon (GAC) used in a water purification system for hemodialysis. XRA-method demonstrated the possibility to determine the exhaustion degree at different layers of the GAC filter. The results of the XRA-method were successfully correlated with X-Ray Fluorescence (XRF), TGA, Elemental analysis (EA), SEM, TD-GC/MS, ATR-FTIR, X Ray Diffraction (XRD) and Nuclear Magnetic Resonance relaxometry (NMR) analyses. It was demonstrated that the XRA-method is a fast and reliable analytical tool to give indirect information on the exhaustion degree of GAC at different layers. It is also demonstrated that XRA results can be correlated with the results of the other analytical techniques, rather dealing with the composition and morphology of GAC at different layers.

Improved bioavailability of Azelnidipine gastro retentive tablets-optimization and in-vivo assessment

Azelnidipine, dihydropyridine based calcium channel blocker has been used for treating ischemic heart disease and cardiac remodeling after myocardial infarction but it is having a low bioavailability due to its poor solubility. The present study is to investigate the formulation and evaluation of floating tablets of Azelnidipine for controlled release and to increase bioavailability by increasing the gastrointestinal transit time and mucoadhesion of drug. The gastro retentive tablets were prepared by direct compression method using different concentrations of combination of Polyoxyethylene oxide WSR 303 as hydrophilic polymer and Potassium bicarbonate as gas generating agent. Main effects of the formulation variables were evaluated quantitatively using design approach showing that both independent variables have significant effects on floating lag time, % drug release at 1 h (D1 h) and time required to release 90% of the drug (t90). The statistically optimized formulation (F3) released 95.11 ± 1.43% drug for 12 h followed K-Peppas drug release kinetics indicating release of drug by diffusion and erosion mechanism. Evaluation of the optimized formulation in vivo in human volunteers showed that the GFT was buoyant in gastric fluid and that its gastric residence time was enhanced. Pharmacokinetics studies carried out revealed significant (P < 0.05) equivalent Cmax, longer Tmax and higher AUC values for the optimized formula compared to the marketed oral product. From the results obtained it can be concluded that Azelnidipine Gastro retentive tablets with enhanced bioavailability and better release pattern is suitable for more effective treatment compared to marketed conventional tablets.

X-ray Computed Tomography for Flame-Structure Analysis of Laminar Premixed Flames

Quantitative X-ray computed tomography (XCT) diagnostics for reacting flows are developed and demonstrated in application to premixed flames in open and optically inaccessible geometries. A laboratory X-ray scanner is employed to investigate methane/air flames that were diluted with krypton as an inert radiodense tracer gas. Effects of acquisition rate and tracer gas concentration on the signal-to-noise ratio are examined. It is shown that statistically converged three-dimensional attenuation measurements can be obtained with limited impact from the tracer gas and within an acceptable acquisition time. Specific aspects of the tomographic reconstruction and the experimental procedure are examined, with particular emphasis on the quantification of experimental uncertainties. A method is developed to determine density and temperature from the X-ray attenuation measurements. These experiments are complemented by one- and multi-dimensional calculations to quantify the influence of krypton on the flame behavior. To demonstrate the merit of XCT for optically inaccessible flames, measurements of a complex flame geometry in a tubular confinement are performed. The use of a coflow to provide a uniform tracer-gas concentration is shown to improve the quantitative temperature evaluation. These measurements demonstrate the viability of XCT for flame-structure analysis and multi-dimensional temperature measurements using laboratory X-ray systems. Further opportunities for improving this diagnostic are discussed.

Pressure Induced Densification and Compression in a Reprocessed Borosilicate Glass

Pressure induced densification and compression of a reprocessed sample of borosilicate glass has been studied by X-ray radiography and energy dispersive X-ray diffraction using a Paris-Edinburgh (PE) press at a synchrotron X-ray source. The reprocessing of a commercial borosilicate glass was carried out by cyclical melting and cooling. Gold foil pressure markers were used to obtain the sample pressure by X-ray diffraction using its known equation of state, while X-ray radiography provided a direct measure of the sample volume at high pressure. The X-ray radiography method for volume measurements at high pressures was validated for a known sample of pure α-Iron to 6.3 GPa. A sample of reprocessed borosilicate glass was compressed to 11.4 GPa using the PE cell, and the flotation density of pressure recovered sample was measured to be 2.755 gm/cc, showing an increase in density of 24%, as compared to the starting sample. The initial compression of the reprocessed borosilicate glass measured by X-ray radiography resulted in a bulk modulus of 30.3 GPa in good agreement with the 32.9 GPa value derived from the known elastic constants. This method can be applied to variety of amorphous materials under high pressures.

Organic-Inorganic Composite Films Based on Gd3Ga3Al2O12:Ce Scintillator Nanoparticles for X-ray Imaging Applications

Organic-inorganic nanocomposite self-standing films of Gd₃Ga₃Al₂O₁₂ (GGAG) uniformly dispersed in poly(methyl methacrylate) (PMMA) and polystyrene polymer are prepared for radiography application. GGAG:Ce nanoscintillator has been chosen because of its high light output and fast decay time. The nanopowder of GGAG is synthesized by coprecipitation method and dispersed in the polymer matrix by a simple blending technique. The nanocomposite films of thickness in the range of 150-450 μm with a very high inorganic content is achieved by this technique. These films are characterized by their uniformity, optical absorption, photoluminescence, and radioluminescence. These films are further tested for their application in radiography by recording X-ray images using a commercially available charge-coupled device camera. A resolution of 10 lp/mm is obtained using GGAG:PMMA composite film with 50% loading, confirming their application in imaging devices.

Preparation and in vitro-in vivo evaluation of acyclovir floating tablets

In the current study, floating dosage form containing acyclovir was developed to increase its oral bioavailability. Effervescent floating tablets containing 200 mg acyclovir were prepared by direct compression method with three different rate controlling polymers including Hydroxypropyl methylcellulose K4M, Carbapol 934, and Polyvinylpyrrolidone. Optimized formulation showed good floating properties and in vitro drug release characteristics with mean dissolution time and dissolution efficacy of about 4.76 h and 54.33%, respectively. X-ray radiography exhibited that the tablet would reside in the stomach for about 5 ± 0.7 h. After oral administration of floating tablet containing 200 mg acyclovir, the C_max, T_max, and AUC_0–∞ of optimized gastroretentive formulation were found to be 551 ± 141 ng/mL, 2.75 ± 0.25 h and 3761 ± 909.6 ng/mL/h, respectively.

Opportunities for Fluorochlorozirconate and Other Glass-Ceramic Detectors in Medical Imaging Devices

This article gives an overview of fluorochlorozirconate glass-ceramic scintillators and storage phosphor materials: how they are synthesized, what their properties are, and how they can be used in medical imaging. Such materials can enhance imaging in x-ray radiography, especially mammography and dental imaging, computed tomography, and positron emission tomography. Although focusing on fluorochlorozirconate materials, the reader will find the discussion is relevant to other luminescent glass and glass-ceramic systems.

Primary intraosseous Kaposi's sarcoma of the maxilla in AIDS: a case report

In China, Kaposi's sarcoma (KS) is very rare. However, KS does occur as one of the complications in patients with acquired immunodeficiency syndrome (AIDS). Usually AIDS-related KS involves the lymph nodes, the skin and gastrointestinal tract. Intraosseous KS have been reported but it is very rare. We report a case of primary intraosseous KS of the maxilla in an AIDS patient, proven by pathology findings and showed multiple metastasis by positron emission tomography and computed tomography (PET/CT). To our knowledge, this is the first report of primary intraosseous KS of the maxilla in an AIDS patient in China.

Processing of projections containing phase contrast in laboratory micro-computerized tomography imaging

Processing of phase-contrast images in laboratory conditions is described.

Free-space-propagation-based imaging belongs to several techniques for achieving phase contrast in the hard X-ray range. The basic precondition is to use an X-ray beam with a high degree of coherence. Although the best sources of coherent X-rays are synchrotrons, spatially coherent X-rays emitted from a sufficiently small spot of laboratory microfocus or sub-microfocus sources allow the transfer of some of the modern imaging techniques from synchrotrons to laboratories. Spatially coherent X-rays traverse a sample leading to a phase shift. Beam deflection induced by the local change of refractive index may be expressed as a dark–bright contrast on the edges of the object in an X-ray projection. This phenomenon of edge enhancement leads to an increase in spatial resolution of X-ray projections but may also lead to unpleasant artefacts in computerized tomography unless phase and absorption contributions are separated. The possibilities of processing X-ray images of lightweight objects containing phase contrast using phase-retrieval methods in laboratory conditions are tested and the results obtained are presented. For this purpose, simulated and recorded X-ray projections taken from a laboratory imaging system with a microfocus X-ray source and a high-resolution CCD camera were processed and a qualitative comparison of results was made.

Diagnostic value of X-ray radiography for the detection of abnormal stoma of oesophageal carcinoma after operation: an analysis of 50 cases

AIM: To analyze the findings of X-ray radio-graphy in abnormal stoma of oesophageal carcinoma after operation and summarize the examination values.

METHODS: Post-operative imaging results from 50 cases of abnormal stoma of oesophageal carcinoma were analyzed retrospectively.

RESULTS: Among the 50 cases, anastomotic stenosis was seen in 21 cases, tumor recurrence in the stoma in 15 cases, stoma fistula in 9 cases, stoma ulcer in 3 cases, and a retained foreign body in the stoma in 2 cases.

CONCLUSION: X-ray radiography may have an important diagnostic value for the detection of abnormal stoma of oesophageal carcinoma after operations, and it offers reliable clinical data.