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Furanoditerpenes of Fibraurea chloroleuca

Zakaria MB, Saito I, Yao XK, Wang RJ, Matsuura T

Planta Med, 1989 Oct;55(5):477-8.
PMID: 17262463

Fibraurin, chasmanthin, and palmarin were isolated from the stems of FIBRAUREA CHLOROLEUCA, Fam. Menispermaceae. The structure of the minor constituent, palmarin, was determined by X-ray crystallographic analysis.

Matched MeSH terms: X-Rays
Fulltext Exploring the effect of image enhancement techniques on COVID-19 detection using chest X-ray images

Rahman T, Khandakar A, Qiblawey Y, Tahir A, Kiranyaz S, Abul Kashem SB, et al.

Comput Biol Med, 2021 May;132:104319.
PMID: 33799220 DOI: 10.1016/j.compbiomed.2021.104319

Computer-aided diagnosis for the reliable and fast detection of coronavirus disease (COVID-19) has become a necessity to prevent the spread of the virus during the pandemic to ease the burden on the healthcare system. Chest X-ray (CXR) imaging has several advantages over other imaging and detection techniques. Numerous works have been reported on COVID-19 detection from a smaller set of original X-ray images. However, the effect of image enhancement and lung segmentation of a large dataset in COVID-19 detection was not reported in the literature. We have compiled a large X-ray dataset (COVQU) consisting of 18,479 CXR images with 8851 normal, 6012 non-COVID lung infections, and 3616 COVID-19 CXR images and their corresponding ground truth lung masks. To the best of our knowledge, this is the largest public COVID positive database and the lung masks. Five different image enhancement techniques: histogram equalization (HE), contrast limited adaptive histogram equalization (CLAHE), image complement, gamma correction, and balance contrast enhancement technique (BCET) were used to investigate the effect of image enhancement techniques on COVID-19 detection. A novel U-Net model was proposed and compared with the standard U-Net model for lung segmentation. Six different pre-trained Convolutional Neural Networks (CNNs) (ResNet18, ResNet50, ResNet101, InceptionV3, DenseNet201, and ChexNet) and a shallow CNN model were investigated on the plain and segmented lung CXR images. The novel U-Net model showed an accuracy, Intersection over Union (IoU), and Dice coefficient of 98.63%, 94.3%, and 96.94%, respectively for lung segmentation. The gamma correction-based enhancement technique outperforms other techniques in detecting COVID-19 from the plain and the segmented lung CXR images. Classification performance from plain CXR images is slightly better than the segmented lung CXR images; however, the reliability of network performance is significantly improved for the segmented lung images, which was observed using the visualization technique. The accuracy, precision, sensitivity, F1-score, and specificity were 95.11%, 94.55%, 94.56%, 94.53%, and 95.59% respectively for the segmented lung images. The proposed approach with very reliable and comparable performance will boost the fast and robust COVID-19 detection using chest X-ray images.

Matched MeSH terms: X-Rays
Fulltext Development of Debiasing Technique for Lung Nodule Chest X-ray Datasets to Generalize Deep Learning Models

Horry MJ, Chakraborty S, Pradhan B, Paul M, Zhu J, Loh HW, et al.

Sensors (Basel), 2023 Jul 21;23(14).
PMID: 37514877 DOI: 10.3390/s23146585

Screening programs for early lung cancer diagnosis are uncommon, primarily due to the challenge of reaching at-risk patients located in rural areas far from medical facilities. To overcome this obstacle, a comprehensive approach is needed that combines mobility, low cost, speed, accuracy, and privacy. One potential solution lies in combining the chest X-ray imaging mode with federated deep learning, ensuring that no single data source can bias the model adversely. This study presents a pre-processing pipeline designed to debias chest X-ray images, thereby enhancing internal classification and external generalization. The pipeline employs a pruning mechanism to train a deep learning model for nodule detection, utilizing the most informative images from a publicly available lung nodule X-ray dataset. Histogram equalization is used to remove systematic differences in image brightness and contrast. Model training is then performed using combinations of lung field segmentation, close cropping, and rib/bone suppression. The resulting deep learning models, generated through this pre-processing pipeline, demonstrate successful generalization on an independent lung nodule dataset. By eliminating confounding variables in chest X-ray images and suppressing signal noise from the bone structures, the proposed deep learning lung nodule detection algorithm achieves an external generalization accuracy of 89%. This approach paves the way for the development of a low-cost and accessible deep learning-based clinical system for lung cancer screening.

Matched MeSH terms: X-Rays
Auto-detection of the coronavirus disease by using deep convolutional neural networks and X-ray photographs

Hussein AM, Sharifai AG, Alia OM, Abualigah L, Almotairi KH, Abujayyab SKM, et al.

Sci Rep, 2024 Jan 04;14(1):534.
PMID: 38177156 DOI: 10.1038/s41598-023-47038-3

The most widely used method for detecting Coronavirus Disease 2019 (COVID-19) is real-time polymerase chain reaction. However, this method has several drawbacks, including high cost, lengthy turnaround time for results, and the potential for false-negative results due to limited sensitivity. To address these issues, additional technologies such as computed tomography (CT) or X-rays have been employed for diagnosing the disease. Chest X-rays are more commonly used than CT scans due to the widespread availability of X-ray machines, lower ionizing radiation, and lower cost of equipment. COVID-19 presents certain radiological biomarkers that can be observed through chest X-rays, making it necessary for radiologists to manually search for these biomarkers. However, this process is time-consuming and prone to errors. Therefore, there is a critical need to develop an automated system for evaluating chest X-rays. Deep learning techniques can be employed to expedite this process. In this study, a deep learning-based method called Custom Convolutional Neural Network (Custom-CNN) is proposed for identifying COVID-19 infection in chest X-rays. The Custom-CNN model consists of eight weighted layers and utilizes strategies like dropout and batch normalization to enhance performance and reduce overfitting. The proposed approach achieved a classification accuracy of 98.19% and aims to accurately classify COVID-19, normal, and pneumonia samples.

Matched MeSH terms: X-Rays
Fulltext Evaluation of X-Ray Beam Quality Based on Measurements and Estimations Using SpekCalc and Ipem78 Models

Chen SC, Jong WL, Harun AZ

Malays J Med Sci, 2012 Jul;19(3):22-8.
PMID: 23610546 MyJurnal

Different computational methods have been used for the prediction of X-ray spectra and beam quality in diagnostic radiology. The purpose of this study was to compare X-ray beam qualities based on half-value layers (HVLs) determined through measurements and computational model estimations.

Matched MeSH terms: X-Rays
Fulltext Absorbed Dose to Water Determination Using IAEA, HPA, NACP, AAPM, NCRP and ICRU Protocols for 1.25 MeV Gamma Ray 6 MV and 10 MV X-Rays: An Intercomparison of Results when IAEA was taken as a Standard Protocol

Dolah MT, Samat SB, Kadni T

Malays J Med Sci, 2000 Jan;7(1):47-53.
PMID: 22844215

Absorbed dose to water was measured with ionisation chambers NE 2561 (#267), NE 2581 (#334), NE 2571 (#1028), using the IAEA standard water phantom. The ionisation chamber was inserted in the water phantom at a reference depth dependent on the type of the radiation quality used. Three radiation qualities were used namely 1.25 MeV gamma ray, 6 MV x-rays and 10 MV x-rays. The values of the absorbed dose to water were determined by the N(K)- and N(X)- based methods, i.e with the use of IAEA, HPA, NACP, AAPM, NCRP and ICRU protocols. The aim of this study was to make an intercomparison of the results, by taking the IAEA protocol as a standard. The largest deviation contributed by any of these protocols was recorded for each quality. It was found that AAPM, NCRP and ICRU protocols contributed 0.94% for 1.25 MeV gamma ray, NACP contributed 2.12% for the 6 MV x-rays, and NACP contributed 2.35% for 10 MV x-rays. Since the acceptable limit of deviation set by the IAEA for this absorbed dose work is ± 3%, it is clear that the overall deviations obtained were all satisfactory.

Matched MeSH terms: X-Rays
X-ray spectra and quality parameters from Monte Carlo simulation and analytical filters

Salehi Z, Ya Ali NK, Yusoff AL

Appl Radiat Isot, 2012 Nov;70(11):2586-9.
PMID: 22940409 DOI: 10.1016/j.apradiso.2011.12.007

BEAMnrc was used to derive the X-ray spectra, from which HVL and homogeneity coefficient were determined, for different kVp and filtration settings. Except for the peak at 61 keV, the spectra are in good agreement with the IPEM report 78 data for the case of filtered beams, whereas the unfiltered beams exhibit softer spectra. Although the current attenuation data deviates from the IPEM 78 data by ~±0.5%, this has negligible effects on the calculated HVL values.

Matched MeSH terms: X-Rays/adverse effects*
Biological polymeric shielding design for an X-ray laboratory using Monte Carlo codes

Tajudin SM, Tabbakh F

Radiol Phys Technol, 2019 Sep;12(3):299-304.
PMID: 31302871 DOI: 10.1007/s12194-019-00522-w

Photon irradiation facilities are often shielded using lead despite its toxicity and high cost. In this study, three Monte Carlo codes, EGS5, MCNPX, and Geant4, were utilized to investigate the efficiency of a relatively new polymeric base compound (CnH2n), as a radiation shielding material for photons with energies below 150 keV. The proposed compound with the densities of 6 and 8 g cm-3 were doped with the weight percentages of 8.0 and 15.0% gadolinium. The probabilities of photoelectric effect and Compton scattering were relatively equal at low photon energies, thus the shielding design was optimized using three Monte Carlo codes for the conformity of calculation results. Consequently, 8% Gd-doped polymer with thickness less than 2 cm and density of 6 g cm-3 was adequate for X-ray room shielding to attenuate more than 95% of the 150-keV incident photons. An average dose rate reduction of 88% can be achieved to ensure safety of the radiation area.

Matched MeSH terms: X-Rays/adverse effects
Fulltext Monitoring model drug microencapsulation in PLGA scaffolds using X-ray powder diffraction

Aina A, Gupta M, Boukari Y, Morris A, Billa N, Doughty S

Saudi Pharm J, 2016 Mar;24(2):227-31.
PMID: 27013917 DOI: 10.1016/j.jsps.2015.03.015

The microencapsulation of three model drugs; metronidazole, paracetamol and sulphapyridine into Poly (dl-Lactide-Co-Glycolide) (PLGA) scaffolds were probed using X-ray Powder Diffraction (XRPD). Changes in the diffraction patterns of the PLGA scaffolds after encapsulation was suggestive of a chemical interaction between the pure drugs and the scaffolds and not a physical intermixture.

Matched MeSH terms: X-Rays
(2E)-1-(5-Chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one: Synthesis, XRD, FT-IR, Raman and DFT studies

Parlak C, Ramasami P, Kumar CS, Tursun M, Quah CK, Rhyman L, et al.

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Oct 5;149:385-95.
PMID: 25974671 DOI: 10.1016/j.saa.2015.04.022

A novel (2E)-1-(5-chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one [C21H15ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The conformational isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of HF, MP2, BP86, BLYP, BMK, B3LYP, B3PW91, B3P86 and M06-2X functionals. Reliable vibrational assignments and molecular orbitals have been investigated by the potential energy distribution and natural bonding orbital analyses, respectively. The compound crystallizes in the triclinic space group P-1 with the cis-trans-trans form. There is a good agreement between the experimentally determined structural parameters and vibrational frequencies of the compound and those predicted theoretically using the density functional theory with the BLYP and BP86 functionals.

Matched MeSH terms: X-Rays
Fulltext Towards holistic radiation protection. lessons from the literatures

Zainul Ibrahim Bin Zainuddin

International Journal of Allied Health Sciences, 2018;2(3):517-527.
MyJurnal

The effects of radiation on man and his health had been noticed since the early years after the discovery of X-rays. These biological concerns were more commonly known as “radio-sensitiveness” in the early publications. Later, the term radiation protection was introduced to express the need for protective measures to be promoted, formulated, implemented, evaluated and sustained to reduce the biological effects associated with radiation exposure. The principles of radiation protection were then supported with the concepts of justification, ALARA and “Benefits against the risks”. But these could not ensure that the application of radiation protection has been optimized. Amidst the technological advancements associated with radiation based imaging modalities in healthcare for more than 120 years, those advancements have yet to be able reduce the impact of these modalities being a source of risks upon the more beneficial role as a
diagnostic tool. This paper reports a review on radiation protection from articles indexed in an online database. Considering that the titles of the articles contain the core subject matter that a publication carries, data were retrieved on those titles with the term “radiation protection”. Publications from 2008 to middle of November 2017 and aligned to Medicine and Health professions were included for further elaborations. The data were classified into four subject areas; education and training, administration and organization, practice and research. Discussions within each classification and their individual sub-classifications, supported by selected publications to the classification, highlight the importance of the particular subject area to the overall concept of radiation protection. Lessons learnt from the classifications could provide the necessary guidance on how one should adopt and adapt the concept of radiation protection holistically. The discussions that are presented are seen within the professional obligation in adhering to the principles of
radiation protection.

Matched MeSH terms: X-Rays
Application of Bpw34 photodiode and cold white LED as diagnostic X-ray detectors: A comparative analysis

Damulira E, Yusoff MNS, Omar AF, Mohd Taib NH, Ahmed NM

Appl Radiat Isot, 2021 Apr;170:109622.
PMID: 33592486 DOI: 10.1016/j.apradiso.2021.109622

This study compares the real-time dosimetric performance of a bpw34 photodiode (PD) and cold white light-emitting diodes (LEDs) based on diagnostic X-ray-induced signals. Signals were extracted when both the transducers were under identical exposure settings, including source-to-detector distance (SDD), tube voltage (kVp), and current-time product (mAs). The transducers were in a photovoltaic configuration, and black vinyl tape was applied on transducer active areas as a form of optical shielding. X-ray beam spectra and energies were simulated using Matlab-based Spektr functions. Transducer performance analysis was based on signal linearity to mAs and air kerma, and sensitivity dependence on absorbed dose, energy, and dose rate. Bpw34 PD and cold white LED output signals were 84.8% and 85.5% precise, respectively. PD signals were 94.7% linear to mAs, whereas LED signals were 91.9%. PD and LED signal linearity to dose coefficients were 0.9397 and 0.9128, respectively. Both transducers exhibited similar dose and energy dependence. However, cold white LEDs were 0.73% less dose rate dependent than the bpw34 PD. Cold white LEDs demonstrated potential in detecting diagnostic X-rays because their performance was similar to that of the bpw34 PD. Moreover, the cold white LED array's dosimetric response was independent of the heel effect. Although cold white LED signals were lower than bpw34 PD signals, they were quantifiable and electronically amplifiable.

Matched MeSH terms: X-Rays
Fulltext PVC as a potential filter material for ionising radiation

Laila Kalidah Junet, Zafri Azran Abdul Majid, Muhammad Syahmi Che Othaman

International Journal of Allied Health Sciences, 2017;1(2):101-107.
MyJurnal

Aluminum (Al) is a standard material that has been used as a filter for ionising radiation however for polyvinyl chloride (PVC) there is no solid evidence to support but has been recommended. PVC has been selected as a potential filter material due to it is a long lasting constructing material and very durable, which can be used in a variety of application. The purpose of this study was to observe the effect of PVC on entrance surface dose (ESD) values as compare to the standard X-ray filter of Al. The effect of varying thickness of the materials and difference exposure settings were observed and compared to each other. From this study, the percentage difference for both PVC and Al thickness is less than ± 25.00 % shows that PVC has a potential to be used as one of the filter materials due to its ability to reduce the ESD value

Matched MeSH terms: X-Rays
Fulltext The effect of different jubah dress’ materials on image quality using computed radiography (CR) on Knee X-Ray: a bovine study

Umi Nadrah Amran, Nur Nadiah Mohd Rais

International Journal of Allied Health Sciences, 2018;2(2):292-303.
MyJurnal

In medical imaging practice, the act of removing any clothes from the region of interest is justified as to prevent the presence of artefacts on radiographs. However, by doing so, the ‘aurah’ of the patients, especially for the Muslims, are not observed and can be considered as violating their privacy if they are not well-informed beforehand. Previous studies have proved that radiographs with the presence of some fabric materials on the region of interest are radiographically acceptable. Therefore, the aims of this study are to tackle the issue of exposing one’s ‘aurah’ for a knee x-ray examination to take place and also to add insufficiency from the previous studies.

Matched MeSH terms: X-Rays
Fractures of the femoral neck

Monro JK

Journal of the Malaya Branch of the British Medical Association, 1940;3:422.

Matched MeSH terms: X-Rays
Fulltext A case of miliary adenocarcinoma of lung masquerading as miliary tuberculosis

Nik Azlan, N.M.

Medicine & Health, 2020;15(1):274-279.
MyJurnal

Adenokarsinoma paru-paru miliari adalah sangat jarang dan agresif. Adenokarsinoma paru-paru biasanya menunjukkan sifat ketulan pada peparu yang berkaitan dengan kerosakan paru-paru dan efusi pleura. Adenokarsinoma ini jarang jarang berpunca daripada tapak selain daripada tapak primer, tidak seperti kanser-kanser lain contohnya kanser tiroid, koriokarsinoma dan sarcoma. Kami membentangkan di sini kes seorang suri rumah berusia 50 tahun yang mengadu batuk-batuk, hilang selera makan dan sukar untuk bernafas selama 1 bulan. Perawat perubatan primer telah merawat beliau sebagai jangkitan kuman pada paru-paru. Disebabkan keadaan yang tidak pulih dan semakin melarat, beliau dibawa ke Jabatan Kecemasan. Oksigen beliau dikesan sebanyak 93% atas udara bilik. Berdasarkan sejarah pesakit dan penemuan X-ray paru-paru, rawatan untuk tuberculosis miliari telah di beri walaupun ujian Mantoux dan kahak negatif. Berikutan peningkatan tanda-tanda dan intubasi, bronkoskopi kemudian mendedahkan diagnosis adenokarsinoma paru-paru. Sebagai pelajaran, penampilan miliari radiografi tidak dikelirukan kepada tuberkulosis sahaja, kerana sebab-sebab berbahaya yang lain perlu disiasat. Bronkoskop dengan analisis histopatologi diperlukan, terutamanya jika Mantoux dan sputum adalah negatif.

Matched MeSH terms: X-Rays
Fulltext Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine

Jamal AbuAlRoos N, Azman MN, Baharul Amin NA, Zainon R

Phys Med, 2020 Oct;78:48-57.
PMID: 32942196 DOI: 10.1016/j.ejmp.2020.08.017

PURPOSE: The main objective of this study was to evaluate the efficacy of tungsten carbide as new lead-free radiation shielding material in nuclear medicine by evaluating the attenuation properties.
MATERIALS AND METHODS: The elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40-50 µm. Three discs of tungsten carbide was fabricated with thickness of 0.1 cm, 0.5 cm and 1.0 cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using 123I, 133Ba, 152Eu, and 137Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160 MeV to 0.779 MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study.
RESULTS: This study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19-5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies.
CONCLUSION: This study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.

Matched MeSH terms: X-Rays
Fulltext Latest recommendations for dental radiography in general dental practice

Purmal, Kathiravan, Nambiar, Phrabhakaran

Malaysian Dental Journal, 2008;29(2):104-112.
MyJurnal

Radiology is important in the diagnostic assessment, treatment and monitoring progress of patients having dental and maxillofacial diseases. The central question in dental radiology is whether there is any risk with regard to low doses of radiation and what are the necessary protection needed to prevent any hazardous outcome with X-raying. With the emergence of the new millennium, major changes are happening in the field of science and technology. More efficient equipments are being discovered and more researches are being conducted to elicit better understanding of the radiation process and its effect on the human health. This article will review the latest guidelines for proper radiographic practice from the USA and Europe. It will address topics like the risks from dental radiography, selection criteria, protection for patients and staff, improvement to X-ray equipments, room dimensions and lead lining requirements. We have limited our research to intraoral, panoramic and cephalometric radiographs because these are the radiographs or images that are commonly taken in the general practice setting. (Copied from article).

Matched MeSH terms: X-Rays
Fulltext Microstructural evolution and growth kinetics of Sn-40Pb/Cu solder joint during long-term aging at 125°C

Mayappan, Ramani, Ahmad Badri Ismail, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2009;2009(1):165-172.
MyJurnal

The microstructural evolution of Sn-40Pb/Cu joints has been investigated under 125 o C thermal exposure conditions using single shear lap joints. A scanning electron microscope (SEM) was used to observe the morphology of the phases and energy dispersive x-ray (EDX) was used to estimate the elemental compositions of the phases. A double layer of Cu6Sn5 and Cu3Sn were observed. The Cu6Sn5 developed with a scalloped morphology, while the Cu3Sn always grew as a somewhat undulated planar layer in phase with the Cu6Sn5. The Cu6Sn5 layer began to transform from scallop shape to planar type after aging for 375 hours due to reduction in the interfacial energy. The intermetallic layers showed a linear dependence on the square root of aging time. The growth rate constant of the intermetallic compounds are estimated as 15.2 x 10 - 14 and 0.152 x 10 -14 cm 2 /s for Cu6Sn5 and Cu3Sn intermetallic, respectively.

Matched MeSH terms: X-Rays
Fulltext Radiographic considerations in endodontics

Yusof, Z.Y.M., Nambiar, P.

Malaysian Dental Journal, 2007;28(1):51-58.
MyJurnal

Quality radiographs of diagnostic value are important in root canal treatment. The dentist who has knowledge and skills in the use of radiographs for diagnostic purposes has a professional responsibility to ensure that the radiographs are obtained with minimum risk of radiation dose to and for the benefit of the patient. This article reviews the effectiveness of radiography techniques required for successful root canal treatment with the patient’s interest in mind. Awareness of effectual radiographic techniques, their constraints and applicable techniques for improvements are discussed. It seeks to reduce potentially harmful ionising radiation dose to patients and optimise the use of X-rays to produce diagnostic radiographs during root canal treatment.

Matched MeSH terms: X-Rays

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