Lionel Tim-Ee Cheng

Dr. Lionel Tim-Ee Cheng

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 September 2023 in npj Digital Medicine
Verified
Journal Article
Open access
PDF file
MLMingxuan Liu
Mingxuan Liu
YNYilin Ning
Yilin Ning
STSalinelat Teixayavong
Salinelat Teixayavong
MMMayli Mertens
Mayli Mertens
JXJie Xu
Jie Xu
Nan LiuNan Liu
Nan Liu
Artificial intelligence (AI) has demonstrated the ability to extract insights from data, but the fairness of such data-driven insights remains a concern in high-stakes fields. Despite extensive developments, issues of AI fairness in clinical contexts have not been adequately addressed. A fair model is normally expected to perform equally across subgroups defined by sensitive variables (e.g., age, gender/sex, race/ethnicity, socio-economic status, etc.). Various fairness measurements have been developed to detect differences between subgroups as evidence of bias, and bias mitigation methods are designed to reduce the differences detected. This perspective of fairness, however, is misaligned with some key considerations in clinical contexts. The set of sensitive variables used in healthcare applications must be carefully examined for relevance and justified by clear clinical motivations. In addition, clinical AI fairness should closely investigate the ethical implications of fairness measurements (e.g., potential conflicts between group- and individual-level fairness) to select suitable and objective metrics. Generally defining AI fairness as “equality” is not necessarily reasonable in clinical settings, as differences may have clinical justifications and do not indicate biases. Instead, “equity” would be an appropriate objective of clinical AI fairness. Moreover, clinical feedback is essential to developing fair and well-performing AI models, and efforts should be made to actively involve clinicians in the process. The adaptation of AI fairness towards healthcare is not self-evident due to misalignments between technical developments and clinical considerations. Multidisciplinary collaboration between AI researchers, clinicians, and ethicists is necessary to bridge the gap and translate AI fairness into real-life benefits.

30 May 2009 in Journal of Digital Imaging
Verified
Journal Article
Open access
PDF file
LCLionel Tim-Ee Cheng
Lionel Tim-Ee Cheng
JZJiaping Zheng
Jiaping Zheng
GSGuergana K. Savova
Guergana K. Savova
BEBradley J. Erickson
Bradley J. Erickson
Information in electronic medical records is often in an unstructured free-text format. This format presents challenges for expedient data retrieval and may fail to convey important findings. Natural language processing (NLP) is an emerging technique for rapid and efficient clinical data retrieval. While proven in disease detection, the utility of NLP in discerning disease progression from free-text reports is untested. We aimed to (1) assess whether unstructured radiology reports contained sufficient information for tumor status classification; (2) develop an NLP-based data extraction tool to determine tumor status from unstructured reports; and (3) compare NLP and human tumor status classification outcomes. Consecutive follow-up brain tumor magnetic resonance imaging reports (2000–­2007) from a tertiary center were manually annotated using consensus guidelines on tumor status. Reports were randomized to NLP training (70%) or testing (30%) groups. The NLP tool utilized a support vector machines model with statistical and rule-based outcomes. Most reports had sufficient information for tumor status classification, although 0.8% did not describe status despite reference to prior examinations. Tumor size was unreported in 68.7% of documents, while 50.3% lacked data on change magnitude when there was detectable progression or regression. Using retrospective human classification as the gold standard, NLP achieved 80.6% sensitivity and 91.6% specificity for tumor status determination (mean positive predictive value, 82.4%; negative predictive value, 92.0%). In conclusion, most reports contained sufficient information for tumor status determination, though variable features were used to describe status. NLP demonstrated good accuracy for tumor status classification and may have novel application for automated disease status classification from electronic databases.

24 November 2009 in Journal of Digital Imaging
Verified
Journal Article
Closed access
PDF file
XYXiaojiang Yang
Xiaojiang Yang
DBDaniel J. Blezek
Daniel J. Blezek
LCLionel Tim-Ee Cheng
Lionel Tim-Ee Cheng
WRWilliam J. Ryan
William J. Ryan
DKDavid F. Kallmes
David F. Kallmes
BEBradley J. Erickson
Bradley J. Erickson

14 June 2025 in npj Digital Medicine
Verified
Journal Article
Open access
PDF file
MLMingxuan Liu
Mingxuan Liu
YNYilin Ning
Yilin Ning
STSalinelat Teixayavong
Salinelat Teixayavong
XLXiaoxuan Liu
Xiaoxuan Liu
MMMayli Mertens
Mayli Mertens
Nan LiuNan Liu
Nan Liu
The ethical integration of artificial intelligence (AI) in healthcare necessitates addressing fairness. AI fairness involves mitigating biases in AI and leveraging AI to promote equity. Despite advancements, significant disconnects persist between technical solutions and clinical applications. Through evidence gap analysis, this review systematically pinpoints the gaps at the intersection of healthcare contexts—including medical fields, healthcare datasets, and bias-relevant attributes (e.g., gender/sex)—and AI fairness techniques for bias detection, evaluation, and mitigation. We highlight the scarcity of AI fairness research in medical domains, the narrow focus on bias-relevant attributes, the dominance of group fairness centering on model performance equality, and the limited integration of clinician-in-the-loop to improve AI fairness. To bridge the gaps, we propose actionable strategies for future research to accelerate the development of AI fairness in healthcare, ultimately advancing equitable healthcare delivery.

1 June 2020 in American Journal of Roentgenology
Verified
Journal Article
Closed access
LCLionel Tim-Ee Cheng
Lionel Tim-Ee Cheng
LCLai Peng Chan
Lai Peng Chan
BTBan Hock Tan
Ban Hock Tan
RCRobert Chun Chen
Robert Chun Chen
KTKiang Hiong Tay
Kiang Hiong Tay
BTBien Soo Tan
Bien Soo Tan
OBJECTIVE. This article shares the ground operational perspective of how a tertiary hospital radiology department in Singapore is responding to the coronavirus disease (COVID-19) epidemic. This sam...

11 July 2023 in iScience
Verified
Journal Article
Open access
YGYan Gao
Yan Gao
NSNicholas Yock Teck Soh
Nicholas Yock Teck Soh
Nan LiuNan Liu
Nan Liu
GLGilbert Lim
Gilbert Lim
DTDarren Shu Jeng Ting
Darren Shu Jeng Ting
YYYet Yen Yan
Yet Yen Yan
This paper describes the development of a deep learning model for prediction of hip fractures on pelvic radiographs (X-rays). Developed using over 40,000 pelvic radiographs from a single institution, the model demonstrated high sensitivity and specificity when applied to a test set of emergency department radiographs. This study approximates the real-world application of a deep learning fracture detection model by including radiographs with sub-optimal image quality, other non-hip fractures, and metallic implants, which were excluded from prior published work. The study also explores the effect of ethnicity on model performance, as well as the accuracy of visualization algorithm for fracture localization.