33 research outputs found
Efficacy And Compatibility Of Blood-Mimicking Fluid In Vascular Wall-Less Flow Phantom For Use In Doppler Ultrasound Applications
Doppler ultrasound (US) tools have been utilized clinically and pre-clinically since 1970s, and they were extremely responsible for the detection of blood flow in arteries and veins. This project shows a general overview focusing on the measuring and calculating the influence of the thickness of protective layer in ultrasonic probe of German Society for Applied Medical Physics and Technology (GAMPT) for the speed of sound (Vs) measurements. Preparing and characterizing new BMF with relatively low-cost, suitable viscosity, and less consuming time for preparation with both new adequate ternary mixture fluid (water (H2O), propylene glycol (PG), and polyethylene glycol (PEG) 200Mw) and with a novel suspension scatter particle (Poly (4-methylstyrene)) to produce a suitable backscatter power comparable to the human blood were explained. Moreover, in this study, the mechanisms of fabrication and characterization a strong (robust) and elastic vascular wall-less flow phantom (TMM and VMM) utilizing a physically strong materials called Konjac (K), Carrageenan (C), and gelatin (bovine skin)-based TMM for high physiological flow rate and detection of the issues related to it by medical Doppler US were explained. The ultrasonic technique was utilized as a main apparatus for acoustical measurements (Vs, attenuation (α), and backscatter power) of BMF and TMM
Blood particulate analogue fluids: A review
Microfluidics has proven to be an extraordinary working platform to mimic and study blood flow phenomena and the dynamics of components of the human microcirculatory system. However, the use of real blood increases the complexity to perform these kinds of in vitro blood experiments due to diverse problems such as coagulation, sample storage, and handling problems. For this reason, interest in the development of fluids with rheological properties similar to those of real blood has grown over the last years. The inclusion of microparticles in blood analogue fluids is essential to reproduce multiphase effects taking place in a microcirculatory system, such as the cell-free layer (CFL) and Fähraeus–Lindqvist effect. In this review, we summarize the progress made in the last twenty years. Size, shape, mechanical properties, and even biological functionalities of microparticles produced/used to mimic red blood cells (RBCs) are critically exposed and analyzed. The methods developed to fabricate these RBC templates are also shown. The dynamic flow/rheology of blood particulate analogue fluids proposed in the literature (with different particle concentrations, in most of the cases, relatively low) is shown and discussed in-depth. Although there have been many advances, the development of a reliable blood particulate analogue fluid, with around 45% by volume of microparticles, continues to be a big challengeThis research was funded by the Spanish Ministry of Science and Education Grant No.
PID2019-108278RB-C32 / AEI / 10.13039/501100011033, and Junta de Extremadura (Spain) Grant
Nos. GR18175 and IB18005 (partially financed by FEDER funds). The authors also acknowledge
the Fundação para a Ciência e a Tecnologia (FCT) for partially financing the research under the
strategic grants UIDB/04077/2020, UIDB/00532/2020, and the project NORTE-01-0145-FEDER030171 (PTDC/EME-SIS/30171/2017) funded by COMPETE2020, NORTE 2020, PORTUGAL 2020,
Lisb@2020, and FEDE
Current Status Regarding Tumour Progression, Surveillance, Diagnosis, Staging, and Treatment Of HCC: A Literature Review
Hepatocellular carcinoma (HCC) is the most common primary malignant tumour of the liver, and is globally considered to be a major causes of cancer-associated mortality. The early diagnosis of HCC improves overall survival through the application of suitable treatment options. This article presents some of the techniques for the surveillance of HCC like ultrasonography and the use of tumour biomarkers such as α-fetoprotein (AFP), DesGamma-Carboxy Prothrombin (DCP) and others. Included in the discussion will be diagnostic methods like computed tomography (CT), magnetic resonance imaging (MRI), contrast enhancement ultrasound (CEUS), and fluorodeoxyglucose positron emission tomography hybrid with computed tomography (FDG PET/CT). Current molecular pathogenesis related to HCC and the molecular steps that determine the transition from benign to malignancy are also analysed. The HCC stages which depends on the Barcelona Clinic Liver Cancer (BCLC) algorithm are also discussed. Finally, this review article discusses the present therapeutic and treatment options for HCC such as resection, transplantation, or ablation used to treat early stage cancer. Also included will be trans-arterial chemoembolization (TACE) and Sorafenib for patients with intermediate and advanced-stage cancer, respectively
Fe-nanoparticle effect on polypropylene for effective radiation protection: Simulation and theoretical study
An evaluation of the gamma-neutron shielding capabilities of polymer nanocomposite materials based on polypropylene and iron nanoparticles is presented in this study. The chemical composition of the materials is (100-x) PP-Fex, (where x = 0.1, 0.3, 0.5, 1, 2 and 5 wt percent). For the proposed polymer samples with photon energies ranging from 30 to 2000 KeV, the mass attenuation coefficient (MAC), a crucial parameter for studying gamma-ray shielding capability, was calculated using the Geant4 Monte Carlo code. Results were compared with those predicted by EpiXS. The values of the Geant4 code and the EpiXS software were both found to be in excellent agreement. Using the mass attenuation coefficient values, we determined the linear attenuation coefficients, electron density, effective atomic number, and half value layer for all the samples. The shielding properties of the polymer samples were also evaluated by estimating both the fast neutron removal cross-section and the mean free path of the fast neutron at energies between 0.25 and 5.5 keV. The study's findings indicate a positive correlation between the Fe nanoparticle content and the gamma-ray shielding performance of PP-Fe polymer samples. Out of the several glasses that were evaluated, it was found that the PP-Fe5 polymer sample demonstrates the highest efficacy in terms of gamma-ray shielding. Moreover, the polymer sample PP-Fe5, which consists of 5 mol% of iron (Fe), exhibits the highest value of ∑R (1.10650 cm-1) and the lowest value of the mean free path for fast neutrons. This indicates that the PP-Fe5 possesses better gamma-neutron shielding efficiency. © 2023 IPE
The Effect Of Ni And Cu Catalysts On The Growth Of Graphene Under Different Ethanol Flow Rates Using Atmospheric Pressure Chemical Vapor Deposition
Graphene was grown on both nickel (Ni) and copper (Cu) catalysts by atmospheric pressure chemical vapor deposition (APCVD) technique at various ethanol flow rates. Raman spectroscopy and field emission scanning electron microscopy (FESEM) were used to study morphological and structural properties of APCVD grown graphene. The crystallite size, defect intensity, distance between defects and the graphene thickness were estimated based on Raman spectra analysis. For the same growth conditions, Ni catalyst promote the formation of more graphene layers as compare to Cu. This because of the higher carbon solubility in Ni as compared to Cu which leads to different growth mechanisms
Characterization and Construction of a Robust and Elastic Wall-Less Flow Phantom for High Pressure Flow Rate Using Doppler Ultrasound Applications
A Doppler ultrasound is a noninvasive test that can be used to estimate the blood flow through the vessels. Presently, few flow phantoms are being used to be qualified for long-term utilize and storage with high physiological flow rate Doppler ultrasound. The main drawback of the two hydrogel materials items (Konjac (K) and carrageenan (C) (KC)) that it is not fit for long-term storage and easy to deteriorate. Thus, this research study focuses on the characterization and construction of a robust and elastic wall-less flow phantom with suitable acoustical properties of TMM. The mechanisms for the fabrication of a wall-less flow phantom utilizing a physically strong material such as K, C, and gelatin (bovine skin)-based TMM were explained. In addition, the clinical ultrasound (Hitachi Avius (HI)) system was used as the main instrument for data acquisition. Vessel mimicking material (VMM) with dimensions of 15.0 mm depth equal to those of human common carotid arteries (CCA) were obtained with pulsatile flow. The acoustical properties (speed of sound and attenuation were 1533±2 m/s and 0.2 dB/cm. MHz, respectively) of a new TMM were agreed with the IEC 61685 standards. Furthermore, the velocity percentages error were decreased with increase in the Doppler angle (the lowest % error (3%) it was at 53◦). The gelatin from bovine skin was a proper material to be added to KC to enhance the strength of TMM during for long-term utilize and storage of high-flow of blood mimicking Fluid (BMF). This wall-less flow phantom will be a suitable instrument for examining in-vitro research studies
Performance Evaluation of an Ultrasonic Imaging System Using Tissue-Mimicking Phantoms for Quality Assurance
Diagnostic ultrasound or sonography is an image that can provide valuable information for diagnosing and treating a variety of diseases and conditions. The aim of this research study is to examine the performance and accuracy of the ultrasonic imaging system for the guarantee of diagnosis quality assurance, and to adjust the penetration settings to minimize the time of repeat scans and maintenance duration during research experiments. Measurements in this experiment included the resolution (axial and lateral) and focal zones. Moreover, the evaluation was done by completing all the measurements at different depths on a multipurpose phantom model 539. The phantom was bought from the market and was not fabricated by the author. The measurements were achieved by applying two different transducers: curved and linear (flat). The ultrasound images were obtained and tested by using calipers (electronic), and the estimations and observations were read by using all the taken measurements and images. As a result, because the phantom depths were different, the penetration settings were different too, indicating that the depth impacted the penetrations of the created ultrasound image. Moreover, after the comparison of the recorded measurements and results, it was found that all measurements were within the accepted (standard) value and that the true value was specified by the production of the phantom
Assessment of Diagnostic Imaging Sector in Public Hospitals in Northern Jordan
The most effective diagnostic methods in the medical field are diagnostic imaging techniques such as radiography, computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine, which are used to visualize internal body to diagnose it, determine potential treatment, and evaluate and forecast care results. Therefore, the purpose of this research is to assess the diagnostic imaging sector, at three major public hospitals in the northern part of Jordan, according to regional and global requirements. The assessment approach was based on knowledge of the accessibility of diagnostic imaging equipment and its quality assurance and performance, the quantity and efficiency of radiological technologists, and the design of radiology units and medical imaging chambers in many aspects based on the use of two tools, a questionnaire and checklists, to accomplish a comprehensive evaluation. The response rate of radiological technologists was 66%. The assessment reveals a noticeable increase in the number of radiological technologists in general with high academic qualification level. Additionally, the number of diagnostic imaging equipment in Jordan revealed a large deficiency in the population–device balance, and through checklists that evaluated both CT and MRI units, it was revealed that the rate of following global requirements and occupational health and safety (OHS) standards was high. The basic supplies available in both the CT and MRI units alike were high, which indicates the high quality of healthcare provided in Jordan
A new scatter particle and mixture fluid for preparing blood mimicking fluid for wall-less flow phantom
The Effect of an Energy Window with an Ellipsoid Phantom on the Differential Defect Contrast on Myocardial SPECT Images
Good quality single-photon emission computed tomography (SPECT) images are required to achieve a perfect diagnosis and determine the severity of defects within the myocardial wall. There are many techniques that can support the diagnosis of defect formations in acquired images and contribute to avoiding errors before image construction. The main aim of this study was to determine the effect of energy width (15%, 20%, and 25%) on defect contrast in myocardial SPECT images correlated with the decentralization of positioning of a phantom. A phantom of polyethylene plastic was used to mimic the myocardial wall of the left ventricle. The phantom consists of two chambers, inner and outer. Two rectangular pieces of plastic were placed in anterior and inferior locations in the mid-region of the myocardial phantom to simulate myocardial infarction (defects). The average defect contrast for all phantom positions using 15% to 20% energy was (1.2, 1.6) for the anterior region and (1.1, 2) for the inferior region, respectively. Additionally, the energy window width was >25% with a large displacement of the positioning off center, leading to loss of the defect contrast in myocardial SPECT images, particularly in the inferior region. The study showed decreasing defect contrast in both locations, anterior and inferior, with increasing energy window width correlated with eccentricity positioning of the phantom on an imaging table