Displaying publications 61 - 80 of 283 in total

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  1. Ng AH, Ng KH, Dharmendra H, Perkins AC
    Appl Radiat Isot, 2009 Oct;67(10):1864-8.
    PMID: 19049851 DOI: 10.1016/j.apradiso.2008.10.010
    A simple sphere test phantom has been developed for routine performance testing of SPECT systems in situations where expensive commercial phantoms may not be available. The phantom was based on a design with six universal syringe hubs set in the frame to support a circular array of six glass blown spheres of different sizes. The frame was then placed into a water-filled CT abdomen phantom and scanned with a triple head camera system (Philips IRIX, USA). Comparison was made with a commercially available phantom (Deluxe Jaszczak phantom). Whereas the commercial phantom demonstrates cold spot resolution, an important advantage of the sphere test phantom was that hot spot resolution could be easily measured using almost half (370MBq) of the activity recommended for use in the commercial phantom. Results showed that the contrast increased non-linearly with sphere volume and radionuclide concentration. The phantom was found to be suitable as an inexpensive option for daily performance tests.
  2. Hashikin NA, Yeong CH, Abdullah BJ, Ng KH, Chung LY, Dahalan R, et al.
    PLoS One, 2015;10(9):e0138106.
    PMID: 26382059 DOI: 10.1371/journal.pone.0138106
    Samarium-153 (153Sm) styrene divinylbenzene microparticles were developed as a surrogate for Yttrium-90 (90Y) microspheres in liver radioembolization therapy. Unlike the pure beta emitter 90Y, 153Sm possess both therapeutic beta and diagnostic gamma radiations, making it possible for post-procedure imaging following therapy.
  3. Hashikin NAA, Yeong CH, Guatelli S, Abdullah BJJ, Ng KH, Malaroda A, et al.
    Phys Med Biol, 2017 Aug 22;62(18):7342-7356.
    PMID: 28686171 DOI: 10.1088/1361-6560/aa7e5b
    We aimed to investigate the validity of the partition model (PM) in estimating the absorbed doses to liver tumour ([Formula: see text]), normal liver tissue ([Formula: see text]) and lungs ([Formula: see text]), when cross-fire irradiations between these compartments are being considered. MIRD-5 phantom incorporated with various treatment parameters, i.e. tumour involvement (TI), tumour-to-normal liver uptake ratio (T/N) and lung shunting (LS), were simulated using the Geant4 Monte Carlo (MC) toolkit. 108track histories were generated for each combination of the three parameters to obtain the absorbed dose per activity uptake in each compartment ([Formula: see text], [Formula: see text], and [Formula: see text]). The administered activities, A were estimated using PM, so as to achieve either limiting doses to normal liver, [Formula: see text] or lungs, [Formula: see text] (70 or 30 Gy, respectively). Using these administered activities, the activity uptake in each compartment ([Formula: see text], [Formula: see text], and [Formula: see text]) was estimated and multiplied with the absorbed dose per activity uptake attained using the MC simulations, to obtain the actual dose received by each compartment. PM overestimated [Formula: see text] by 11.7% in all cases, due to the escaped particles from the lungs. [Formula: see text] and [Formula: see text] by MC were largely affected by T/N, which were not considered by PM due to cross-fire exclusion at the tumour-normal liver boundary. These have resulted in the overestimation of [Formula: see text] by up to 8% and underestimation of [Formula: see text] by as high as  -78%, by PM. When [Formula: see text] was estimated via PM, the MC simulations showed significantly higher [Formula: see text] for cases with higher T/N, and LS  ⩽  10%. All [Formula: see text] and [Formula: see text] by MC were overestimated by PM, thus [Formula: see text] were never exceeded. PM leads to inaccurate dose estimations due to the exclusion of cross-fire irradiation, i.e. between the tumour and normal liver tissue. Caution should be taken for cases with higher TI and T/N, and lower LS, as they contribute to major underestimation of [Formula: see text]. For [Formula: see text], a different correction factor for dose calculation may be used for improved accuracy.
  4. Ng KH, Peh WC
    Singapore Med J, 2009 Apr;50(4):330-4; quiz 335.
    PMID: 19421674
    In part two of "Preparing effective illustrations", the other three categories, viz. photographs, radiological images and diagrams, are discussed. Illustrations provide visual information to supplement the results in a scientific paper, and create a visual impact that can improve the readability of a paper. This article provides some basic guidelines to assist authors in preparing effective photographs, radiological images and diagrams.
  5. Ng KH, Peh WC
    Singapore Med J, 2009 Mar;50(3):245-9.
    PMID: 19352565
    Illustrations (also known as figures) are visual representations of the results obtained from a scientific study. Graphs are a common type of illustration that are often used in scientific papers to present information clearly and effectively, as well as to demonstrate relationships between variables in the data. Graphs also serve to reveal trends or patterns in the data. This article provides some basic guidelines to assist authors in preparing effective graphs for their papers.
  6. Ng KH, Peh WC
    Singapore Med J, 2009 May;50(5):458-60; quiz 461.
    PMID: 19495512
    The discussion section comprises the last component in the IMRAD system. The purpose of this section is to provide the interpretation of the results obtained, explain the implications of the findings, state study limitations and make suggestions for future research. This is a critical part of the scientific paper, as it places the particular study within the broader context of how the research contributes to improving diagnosis, treatment or patient care.
  7. Ng KH, Peh WC
    Singapore Med J, 2009 Dec;50(12):1134-7; quiz 1138.
    PMID: 20087547
    After submission and acceptance of a scientific paper by a journal, the final stages in the publishing process are copy-editing and proofreading. The primary purpose of this step is to ensure accurate and quality production of scientific papers. Authors are responsible for checking their proofs properly and in detail, ensuring that everything is correct as this is their last chance to make any changes before their work is set in print forever.
  8. Ng KH, Peh WC
    Singapore Med J, 2010 Oct;51(10):757-60; quiz 761.
    PMID: 21103809
    A bibliographic database is an organised digital collection of references to published literature. A bibliographic database may be general in scope or may cover a specific academic discipline. There are many types of medical and general bibliographic databases. They cover biomedical and scientific literature, morbidity and mortality statistics, therapeutic regimens, medical records, images and reviews of evidence-based medicine. Getting to know these databases will help researchers and authors to enhance their writing and publishing endeavours.
  9. Ng KH, Peh WC
    Singapore Med J, 2010 Feb;51(2):101-3; quiz 104.
    PMID: 20358146
    A technical note is a short article giving a brief description of a specific development, technique or procedure, or it may describe a modification of an existing technique, procedure or device applicable to medicine. The technique, procedure or device described should have practical value and should contribute to clinical diagnosis or management. It could also present a software tool, or an experimental or computational method. Technical notes are variously referred to as technical innovations or technical developments. The main criteria for publication will be the novelty of concepts involved, the validity of the technique and its potential for clinical applications.
  10. Ng KH, Peh WC
    Singapore Med J, 2008 Nov;49(11):856-8; quiz 859.
    PMID: 19037549
    When writing scientific papers to share their research findings with their peers, it is not enough for researchers to just communicate the results of their study; it is equally important to explain the process by which they arrived at their results, so that the study can be replicated to validate the observations. The materials and methods section is used to describe the experimental design and provide sufficient details so that a competent colleague can repeat the experiment. A good materials and methods section will enable readers to evaluate the research performed and replicate the study, if necessary.
  11. Ng KH, Peh WC
    Singapore Med J, 2009 Feb;50(2):117-8; quiz 119.
    PMID: 19296024
    Tables are used in scientific papers to present information in a concise and efficient manner. Tables are able to provide information at any desired level of detail and precision. Presenting data in a table rather than as part of the text is also an effective way to reduce the length of the text. This article provides some basic guidelines to assist authors in preparing clear and effective tables for their papers.
  12. Ng KH, Peh WC
    Singapore Med J, 2009 Jan;50(1):11-4.
    PMID: 19224078
    Statistical methods are reported in a scientific paper to summarise the data that has been collected for a study and to enable its analysis. These methods should be described with enough detail to allow a knowledgeable reader who has access to the original data to verify the reported results. This article provides basic guidelines to aid authors in reporting the statistical aspects of the results of their studies clearly and accurately.
  13. Ng KH, Peh WC
    Singapore Med J, 2008 Dec;49(12):967-8; quiz 969.
    PMID: 19122944
    The purpose of the results section is to present the main data collected and the observations made during the research. It provides interpretation of the analysed data and does not contain details on the methods, materials or discussion. The first step in writing the results section is to review the analysed data and determine which results to present. This can be done by deciding which results are relevant to the question(s) presented in the introduction, and may be supplemented by illustrative tables and figures. The results section guides the reader through the questions investigated in the study and sets the stage for the discussion in the next section.
  14. Ng KH, Peh WC
    Singapore Med J, 2010 May;51(5):362-6.
    PMID: 20593139
    Evidence-based medicine (EBM) aims to combine the best available scientific evidence with clinical experience and individual judgment of patient needs. In the hierarchy of scientific evidence, systematic reviews (along with meta-analyses) occupy the highest levels in terms of the quality of evidence. A systematic review is the process of searching, selecting, appraising, synthesising and reporting clinical evidence on a particular question or topic. It is currently considered the best, least biased and most rational way to organise, gather, evaluate and integrate scientific evidence from the rapidly-changing medical and healthcare literature. Systematic reviews could be used to present current concepts or serve as review articles and replace the traditional expert opinion or narrative review. This article explains the structure and content of a systematic review.
  15. Abdullah BJ, Ng KH, Pathmanathan R
    Med J Malaysia, 1999 Jun;54(2):169-74.
    PMID: 10972025
    Teleradiology is the most mature and rapidly evolving specialty in telemedicine. The use of teleradiology has grown tremendously during the past few years. This article describes the role of teleradiology in health care along with a brief history of its development in tandem with advances in telecommunications and computer technologies. Teleradiology standards, image acquisition, data compression, transmission and image interpretation are summarised. The impact of teleradiology in the practice of radiology, traces the evolution of the modality especially in the Malaysian perspective and its current and future role are discussed.
  16. Law KB, Chang KM, Hamzah NA, Ng KH, Ong TC
    Indian J Hematol Blood Transfus, 2017 Dec;33(4):483-491.
    PMID: 29075058 DOI: 10.1007/s12288-017-0790-3
    The study aimed to investigate the effect of consolidation treatment with fludarabine, high-dose cytarabine and granulocyte colony-stimulating factor or FLAG in older AML patients. The study included 41 eligible patients above 54 years old, who received both induction and consolidation chemotherapy for AML from 2008 to 2013. The study cohort had a minimum 24 months follow-up period. Survival analysis was carried out to assess patients' overall survival and disease free survival based on types of consolidation regimens. The consolidation treatment with FLAG exerted a protective effect to both overall survival and disease free survival in older patients. Patients who were consolidated with FLAG regimen had a significant longer overall survival (log-rank, p = 0.0025) and disease free survival (log-rank, p = 0.0026). The median overall survival was longer (18.70 months) with the use of FLAG when compared to non-FLAG group (8.09 months). The median disease free survival was also longer (13.84 months) with use of FLAG when compared to the non-FLAG group (4.44 months). Regression analysis with Cox model yielded hazard ratio of 0.245 (p = 0.0094) in overall survival and 0.217 (p = 0.0068) in disease free survival. The use of FLAG as consolidation treatment was associated with approximately 60-80% reduction in hazard rates. The result was adjusted for age, race and gender in regression analysis. Older AML patients had longer remission and survival when consolidated with FLAG regimen after the induction chemotherapy.
  17. Zhu CZ, Ting HN, Ng KH, Ong TA
    J Cancer, 2019;10(17):4038-4044.
    PMID: 31417648 DOI: 10.7150/jca.28989
    Background and purpose: Bladder cancer is the most common malignant tumour in the urinary system, with a high incidence and recurrence rate. While the incidence of bladder cancer has been rising in recent years, the prevalence of bladder carcinoma is showing an increasing tendency in the younger age group. There are several methods to detect bladder cancer, but different methods have varying degrees of accuracy which intrinsically depends on the method's sensitivity and specificity. Our aim was to comprehensively summarize the current detection methods for bladder cancer based on the available literature, and at the same time, to find the best combination of different effective methods which can produce a high degree of accuracy in detecting the presence of cancerous cells in the bladder. Materials and Methods: We used key word retrieval method for searching related references in English that had been indexed in PubMed and Medline. Results and Discussion: This paper discussed the different detection methods and their sensitivities/specificities as well as the advantages and disadvantages. We summarized the best identified cancer cell detection methods with higher sensitivity/specificity. Conclusion: The results of this review can positively help to identify accurate methods for detecting bladder cancer and highlight areas to be further improved for future research work.
  18. Zhu CZ, Ting HN, Ng KH, Mun KS, Ong TA
    Phys Eng Sci Med, 2024 Mar;47(1):61-71.
    PMID: 37843766 DOI: 10.1007/s13246-023-01341-5
    Many studies have investigated the dielectric properties of human and animal tissues, particularly to differentiate between normal cells and tumors. However, these studies are invasive as tissue samples have to be excised to measure the properties. This study aims to investigate the dielectric properties of urine in relation to bladder cancer, which is safe and non-invasive to patients. 30 healthy subjects and 30 bladder cancer patients were recruited. Their urine samples were subjected to urinalysis and cytology assessment. A vector network analyzer was used to measure the dielectric constant (Ɛ') and loss factor (Ɛ″) at microwave frequencies of between 0.2 and 50 GHz at 25 °C, 30 °C and 37 °C. Significant differences in Ɛ' and Ɛ″ were observed between healthy subjects and patients, especially at frequencies of between 25 and 40 GHz at 25 °C. Bladder cancer patients had significant lower Ɛ' and higher Ɛ″ compared with healthy subjects. The Ɛ' was negatively correlated with urinary exfoliated urothelial cell number, and Ɛ″ was positively correlated. The study achieved a receiver operating characteristic area under curve (ROC-AUC) score of 0.69099 and an optimum accuracy of 75% with a sensitivity of 80% and a specificity of 70%. The number of exfoliated urothelial cell had significant effect on the dielectric properties, especially in bladder cancer patients. Urinary dielectric properties could potentially be used as a tool to detect bladder cancer.
  19. Azlan CA, Ng KH, Anandan S, Nizam MS
    Australas Phys Eng Sci Med, 2006 Sep;29(3):278-80.
    PMID: 17058591
    Illuminance level in the softcopy image viewing room is a very important factor to optimize productivity in radiological diagnosis. In today's radiological environment, the illuminance measurements are normally done during the quality control procedure and performed annually. Although the room is equipped with dimmer switches, radiologists are not able to decide the level of illuminance according to the standards. The aim of this study is to develop a simple real-time illuminance detector system to assist the radiologists in deciding an adequate illuminance level during radiological image viewing. The system indicates illuminance in a very simple visual form by using light emitting diodes. By employing the device in the viewing room, illuminance level can be monitored and adjusted effectively.
  20. Round WH, Jafari S, Kron T, Azhari HA, Chhom S, Hu Y, et al.
    Australas Phys Eng Sci Med, 2015 Sep;38(3):525.
    PMID: 26349560 DOI: 10.1007/s13246-015-0370-5
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