Displaying all 13 publications

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  1. Chong BS, Abdullah D, Liew AKC, Khazin SM
    Br Dent J, 2021 03;230(5):273.
    PMID: 33712761 DOI: 10.1038/s41415-021-2797-2
  2. Liew A, Lee CC, Lan BL, Tan M
    Comput Biol Med, 2021 09;136:104690.
    PMID: 34352452 DOI: 10.1016/j.compbiomed.2021.104690
    Convolutional neural networks (CNNs) have been used quite successfully for semantic segmentation of brain tumors. However, current CNNs and attention mechanisms are stochastic in nature and neglect the morphological indicators used by radiologists to manually annotate regions of interest. In this paper, we introduce a channel and spatial wise asymmetric attention (CASPIAN) by leveraging the inherent structure of tumors to detect regions of saliency. To demonstrate the efficacy of our proposed layer, we integrate this into a well-established convolutional neural network (CNN) architecture to achieve higher Dice scores, with less GPU resources. Also, we investigate the inclusion of auxiliary multiscale and multiplanar attention branches to increase the spatial context crucial in semantic segmentation tasks. The resulting architecture is the new CASPIANET++, which achieves Dice Scores of 91.19%, 87.6% and 81.03% for whole tumor, tumor core and enhancing tumor respectively. Furthermore, driven by the scarcity of brain tumor data, we investigate the Noisy Student method for segmentation tasks. Our new Noisy Student Curriculum Learning paradigm, which infuses noise incrementally to increase the complexity of the training images exposed to the network, further boosts the enhancing tumor region to 81.53%. Additional validation performed on the BraTS2020 data shows that the Noisy Student Curriculum Learning method works well without any additional training or finetuning.
  3. Liew A, Lee CC, Subramaniam V, Lan BL, Tan M
    J Magn Reson Imaging, 2023 Jun;57(6):1728-1740.
    PMID: 36208095 DOI: 10.1002/jmri.28456
    BACKGROUND: Research suggests that treatment of multiple brain metastases (BMs) with stereotactic radiosurgery shows improvement when metastases are detected early, providing a case for BM detection capabilities on small lesions.

    PURPOSE: To demonstrate automatic detection of BM on three MRI datasets using a deep learning-based approach. To improve the performance of the network is iteratively co-trained with datasets from different domains. A systematic approach is proposed to prevent catastrophic forgetting during co-training.

    STUDY TYPE: Retrospective.

    POPULATION: A total of 156 patients (105 ground truth and 51 pseudo labels) with 1502 BM (BrainMetShare); 121 patients with 722 BM (local); 400 patients with 447 primary gliomas (BrATS). Training/pseudo labels/validation data were distributed 84/51/21 (BrainMetShare). Training/validation data were split: 121/23 (local) and 375/25 (BrATS).

    FIELD STRENGTH/SEQUENCE: A 5 T and 3 T/T1 spin-echo postcontrast (T1-gradient echo) (BrainMetShare), 3 T/T1 magnetization prepared rapid acquisition gradient echo postcontrast (T1-MPRAGE) (local), 0.5 T, 1 T, and 1.16 T/T1-weighted-fluid-attenuated inversion recovery (T1-FLAIR) (BrATS).

    ASSESSMENT: The ground truth was manually segmented by two (BrainMetShare) and four (BrATS) radiologists and manually annotated by one (local) radiologist. Confidence and volume based domain adaptation (CAVEAT) method of co-training the three datasets on a 3D nonlocal convolutional neural network (CNN) architecture was implemented to detect BM.

    STATISTICAL TESTS: The performance was evaluated using sensitivity and false positive rates per patient (FP/patient) and free receiver operating characteristic (FROC) analysis at seven predefined (1/8, 1/4, 1/2, 1, 2, 4, and 8) FPs per scan.

    RESULTS: The sensitivity and FP/patient from a held-out set registered 0.811 at 2.952 FP/patient (BrainMetShare), 0.74 at 3.130 (local), and 0.723 at 2.240 (BrATS) using the CAVEAT approach with lesions as small as 1 mm being detected.

    DATA CONCLUSION: Improved sensitivities at lower FP can be achieved by co-training datasets via the CAVEAT paradigm to address the problem of data sparsity.

    LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

  4. Liew A, Lydia A, Matawaran BJ, Susantitaphong P, Tran HTB, Lim LL
    Nephrology (Carlton), 2023 Aug;28(8):415-424.
    PMID: 37153973 DOI: 10.1111/nep.14167
    Recent clinical studies have demonstrated the effectiveness of SGLT-2 inhibitors in reducing the risks of cardiovascular and renal events in both patients with and without type 2 diabetes mellitus. Consequently, many international guidelines have begun advocating for the use of SGLT-2 inhibitors for the purpose of organ protection rather than as simply a glucose-lowering agent. However, despite the consistent clinical benefits and available strong guideline recommendations, the utilization of SGLT-2 inhibitors have been unexpectedly low in many countries, a trend which is much more noticeable in low resource settings. Unfamiliarity with the recent focus in their organ protective role and clinical indications; concerns with potential adverse effects of SGLT-2 inhibitors, including acute kidney injury, genitourinary infections, euglycemic ketoacidosis; and their safety profile in elderly populations have been identified as deterring factors to their more widespread use. This review serves as a practical guide to clinicians managing patients who could benefit from SGLT-2 inhibitors treatment and instill greater confidence in the initiation of these drugs, with the aim of optimizing their utilization rates in high-risk populations.
  5. Kerr PG, Tran HTB, Ha Phan HA, Liew A, Hooi LS, Johnson DW, et al.
    Kidney Int, 2018 09;94(3):465-470.
    PMID: 30045813 DOI: 10.1016/j.kint.2018.05.014
  6. Wijewickrama ES, Abdul Hafidz MI, Robinson BM, Johnson DW, Liew A, Dreyer G, et al.
    BMJ Open, 2022 Dec 30;12(12):e065112.
    PMID: 36585149 DOI: 10.1136/bmjopen-2022-065112
    OBJECTIVE: Patients with advanced chronic kidney disease (CKD) or kidney failure receiving replacement therapy (KFRT) are highly vulnerable to COVID-19 infection, morbidity and mortality. Vaccination is effective, but access differs around the world. We aimed to ascertain the availability, readiness and prioritisation of COVID-19 vaccines for this group of patients globally.

    SETTING AND PARTICIPANTS: Collaborators from the International Society of Nephrology (ISN), Dialysis Outcomes and Practice Patterns Study and ISN-Global Kidney Health Atlas developed an online survey that was administered electronically to key nephrology leaders in 174 countries between 2 July and 4 August 2021.

    RESULTS: Survey responses were received from 99 of 174 countries from all 10 ISN regions, among which 88/174 (50%) were complete. At least one vaccine was available in 96/99 (97%) countries. In 71% of the countries surveyed, patients on dialysis were prioritised for vaccination, followed by patients living with a kidney transplant (KT) (62%) and stage 4/5 CKD (51%). Healthcare workers were the most common high priority group for vaccination. At least 50% of patients receiving in-centre haemodialysis, peritoneal dialysis or KT were estimated to have completed vaccination at the time of the survey in 55%, 64% and 51% of countries, respectively. At least 50% of patients in all three patient groups had been vaccinated in >70% of high-income countries and in 100% of respondent countries in Western Europe.The most common barriers to vaccination of patients were vaccine hesitancy (74%), vaccine shortages (61%) and mass vaccine distribution challenges (48%). These were reported more in low-income and lower middle-income countries compared with high-income countries.

    CONCLUSION: Patients with advanced CKD or KFRT were prioritised in COVID-19 vaccination in most countries. Multiple barriers led to substantial variability in the successful achievement of COVID-19 vaccination across the world, with high-income countries achieving the most access and success.

  7. Liew A, Bavanandan S, Prasad N, Wong MG, Chang JM, Eiam-Ong S, et al.
    Nephrology (Carlton), 2020 10;25 Suppl 2:12-45.
    PMID: 33111477 DOI: 10.1111/nep.13785
  8. Tang SCW, Yu X, Chen HC, Kashihara N, Park HC, Liew A, et al.
    Am J Kidney Dis, 2020 05;75(5):772-781.
    PMID: 31699518 DOI: 10.1053/j.ajkd.2019.08.005
    Asia is the largest and most populated continent in the world, with a high burden of kidney failure. In this Policy Forum article, we explore dialysis care and dialysis funding in 17 countries in Asia, describing conditions in both developed and developing nations across the region. In 13 of the 17 countries surveyed, diabetes is the most common cause of kidney failure. Due to great variation in gross domestic product per capita across Asian countries, disparities in the provision of kidney replacement therapy (KRT) exist both within and between countries. A number of Asian nations have satisfactory access to KRT and have comprehensive KRT registries to help inform practices, but some do not, particularly among low- and low-to-middle-income countries. Given these differences, we describe the economic status, burden of kidney failure, and cost of KRT across the different modalities to both governments and patients and how changes in health policy over time affect outcomes. Emerging trends suggest that more affluent nations and those with universal health care or access to insurance have much higher prevalent dialysis and transplantation rates, while in less affluent nations, dialysis access may be limited and when available, provided less frequently than optimal. These trends are also reflected by an association between nephrologist prevalence and individual nations' incomes and a disparity in the number of nephrologists per million population and per thousand KRT patients.
  9. Wang AY, Akizawa T, Bavanandan S, Hamano T, Liew A, Lu KC, et al.
    Kidney Int Rep, 2019 Nov;4(11):1523-1537.
    PMID: 31890994 DOI: 10.1016/j.ekir.2019.09.007
    Improving Global Outcomes (KDIGO) Clinical Practice Guideline on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) 2009 provided recommendations on the detection, evaluation, and treatment of CKD-MBD in patients CKD who are and are not undergoing dialysis. Because of the accumulation of evidence since this initial publication, the CKD-MBD Guideline underwent a selective update in 2017. In April 2018, KDIGO convened a CKD-MBD Guideline Implementation Summit in Japan with the key objective to discuss various barriers to the uptake and implementation of the CKD-MBD Guideline in 8 Asian countries/regions. These countries/regions were comparable according to their high-to-middle economic ranking assigned by the World Bank. The discussion took into account the availability of CKD-MBD medication therapies and government health policies that may influence reimbursement and practice patterns in the region. Most importantly, Summit participants developed a framework of multifaceted strategies aimed at overcoming barriers to guideline implementation. The Summit attendees suggested a shared decision-making approach between clinicians and patients in CKD-MBD management, as well as individualized care based on the treatment risk-benefit ratio. The Summit participants also discussed how KDIGO, as a guideline development organization, may work in partnership with local and national nephrology societies to provide education and facilitate implementation of the guideline by clinicians. The conclusions drawn from this Summit in Asia may serve as an important guide for other regions to follow.
  10. Luyckx VA, Martin DE, Moosa MR, Bello AK, Bellorin-Font E, Chan TM, et al.
    Kidney Int Suppl (2011), 2020 Mar;10(1):e72-e77.
    PMID: 32149011 DOI: 10.1016/j.kisu.2019.11.003
    Ethical issues relating to end-stage kidney disease (ESKD) care are increasingly being discussed by clinicians and ethicists but are still infrequently considered at a policy level or in the education and training of health care professionals. In most lower-income countries, access to kidney replacement therapies such as dialysis is not universal, leading to overt or implicit rationing of resources and potential exclusion from care of those who are unable to sustain out-of-pocket payments. These circumstances create significant inequities in access to ESKD care within and between countries and impose emotional and moral burdens on patients, families, and health care workers involved in decision-making and provision of care. End-of-life decision-making in the context of ESKD care in all countries may also create ethical dilemmas for policy makers, professionals, patients, and their families. This review outlines several ethical implications of the complex challenges that arise in the management of ESKD care around the world. We argue that more work is required to develop the ethics of ESKD care, so as to provide ethical guidance in decision-making and education and training for professionals that will support ethical practice in delivery of ESKD care. We briefly review steps that may be required to accomplish this goal, discussing potential barriers and strategies for success.
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