1.Neuroprotective Mechanisms of Ciliary Neurotrophic Factor in Retinal Ganglion Cells: Insights from Microarray Analysis
Seungyeon LEE ; Jin-Ok CHOI ; Ahreum HWANG ; Chan Yun KIM ; Kwanghyun LEE
Korean Journal of Ophthalmology 2025;39(2):125-133
Purpose:
This study investigated the changes in gene expression in retinal ganglion cells (RGCs) following ciliary neurotrophic factor (CNTF) treatment to elucidate the underlying mechanisms contributing to its neuroprotective effects.
Methods:
RGCs isolated from Sprague-Dawley rat pups were treated with recombinant CNTF. Gene expression was analyzed via microarray. Differentially expressed genes (DEGs) were defined as those with a fold change greater than 2 or less than –2. The DEGs were further explored using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses.
Results:
Our analysis identified 71 upregulated and 58 downregulated genes. A2m exhibited the highest increase, with a fold change of 4.97, whereas Rho displayed the most significant decrease in expression, with a fold change of –6.38. GO and KEGG pathway analyses revealed substantial involvement in sensory organ development and the phototransduction pathway.
Conclusions
This study provides new insights into the impact of CNTF on gene expression in RGCs, suggesting broader neuroprotective mechanisms that could inform future therapeutic strategies for retinal degenerative diseases. Our findings emphasize the importance of further investigation into the complex gene network responses to CNTF treatment.
2.Establishment of Local Diagnostic Reference Levels for Pediatric Neck CT at Nine University Hospitals in South Korea
Jisun HWANG ; Hee Mang YOON ; Jae-Yeon HWANG ; Young Hun CHOI ; Yun Young LEE ; So Mi LEE ; Young Jin RYU ; Sun Kyoung YOU ; Ji Eun PARK ; Seok Kee LEE
Korean Journal of Radiology 2025;26(1):65-74
Objective:
To establish local diagnostic reference levels (DRLs) for pediatric neck CT based on age, weight, and water-equivalent diameter (WED) across multiple university hospitals in South Korea.
Materials and Methods:
This retrospective study analyzed pediatric neck CT examinations from nine university hospitals, involving patients aged 0–18 years. Data were categorized by age, weight, and WED, and radiation dose metrics, including volume CT dose index (CTDIvol) and dose length product, were recorded. Data retrieval and analysis were conducted using a commercially available dose-management system (Radimetrics, Bayer Healthcare). Local DRLs were established following the International Commission on Radiological Protection guidelines, using the 75th percentile as the reference value.
Results:
A total of 1159 CT examinations were analyzed, including 169 scans from Institution 1, 132 from Institution 2, 126 from Institution 3, 129 from Institution 4, 128 from Institution 5, 105 from Institution 6, 162 from Institution 7, 127 from Institution 8, and 81 from Institution 9. Radiation dose metrics increased with age, weight, and WED, showing significant variability both within and across institutions. For patients weighing less than 10 kg, the DRL for CTDIvol was 5.2 mGy. In the 10–19 kg group, the DRL was 5.8 mGy; in the 20–39 kg group, 7.6 mGy; in the 40–59 kg group, 11.0 mGy; and for patients weighing 60 kg or more, 16.2 mGy. DRLs for CTDIvol by age groups were as follows: 5.3 mGy for infants under 1 year, 5.7 mGy for children aged 1–4 years, 7.6 mGy for ages 5–9 years, 11.2 mGy for ages 10–14 years, and 15.6 mGy for patients 15 years or older.
Conclusion
Local DRLs for pediatric neck CT were established based on age, weight, and WED across nine university hospitals in South Korea.
3.Ultrafast MRI for Pediatric Brain Assessment in Routine Clinical Practice
Hee Eun MOON ; Ji Young HA ; Jae Won CHOI ; Seung Hyun LEE ; Jae-Yeon HWANG ; Young Hun CHOI ; Jung-Eun CHEON ; Yeon Jin CHO
Korean Journal of Radiology 2025;26(1):75-87
Objective:
To assess the feasibility of ultrafast brain magnetic resonance imaging (MRI) in pediatric patients.
Materials and Methods:
We retrospectively reviewed 194 pediatric patients aged 0 to 19 years (median 10.2 years) who underwent both ultrafast and conventional brain MRI between May 2019 and August 2020. Ultrafast MRI sequences included T1 and T2-weighted images (T1WI and T2WI), fluid-attenuated inversion recovery (FLAIR), T2*-weighted image (T2*WI), and diffusion-weighted image (DWI). Qualitative image quality and lesion evaluations were conducted on 5-point Likert scales by two blinded radiologists, with quantitative assessment of lesion count and size on T1WI, T2WI, and FLAIR sequences for each protocol. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) analyses were used for comparison.
Results:
The total scan times for equivalent image contrasts were 1 minute 44 seconds for ultrafast MRI and 15 minutes 30 seconds for conventional MRI. Overall, image quality was lower in ultrafast MRI than in conventional MRI, with mean quality scores ranging from 2.0 to 4.8 for ultrafast MRI and 4.8 to 5.0 for conventional MRI across sequences (P < 0.001 for T1WI, T2WI, FLAIR, and T2*WI for both readers; P = 0.018 [reader 1] and 0.031 [reader 2] for DWI). Lesion detection rates on ultrafast MRI relative to conventional MRI were as follows: T1WI, 97.1%; T2WI, 99.6%; FLAIR, 92.9%; T2*WI, 74.1%; and DWI, 100%. The ICC (95% confidence interval) for lesion size measurements between ultrafast and conventional MRI was as follows: T1WI, 0.998 (0.996–0.999); T2WI, 0.998 (0.997–0.999); and FLAIR, 0.99 (0.985–0.994).
Conclusion
Ultrafast MRI significantly reduces scan time and provides acceptable results, albeit with slightly lower image quality than conventional MRI, for evaluating intracranial abnormalities in pediatric patients.
4.Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences
Kyu Sung CHOI ; Chanrim PARK ; Ji Ye LEE ; Kyung Hoon LEE ; Young Hun JEON ; Inpyeong HWANG ; Roh Eul YOO ; Tae Jin YUN ; Mi Ji LEE ; Keun-Hwa JUNG ; Koung Mi KANG
Korean Journal of Radiology 2025;26(1):54-64
Objective:
To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.
Materials and Methods:
This study included 150 participants (51 male; mean age 57.3 ± 16.2 years). Each group of 50 participants was scanned using one of three 3T scanners from three different vendors. Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1- and T2-weighted and 3D gradient-echo sequences. Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images. The scan times of Accel-DL and conventional MRI methods were compared. Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5- and 3-point scales). Inter-reader agreement was assessed using Fleiss’ kappa coefficient. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.
Results:
Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%–51.3%). Accel-DL improved overall image quality (3.78 ± 0.71 vs. 3.36 ± 0.61, P < 0.001), structure delineation (2.47 ± 0.61 vs. 2.35 ± 0.62, P < 0.001), and artifacts (3.73 ± 0.72 vs. 3.71 ± 0.69, P = 0.016). Inter-reader agreement was fair to substantial (κ = 0.34–0.50). SNR and CNR increased in Accel-DL (82.0 ± 23.1 vs. 31.4 ± 10.8, P = 0.02; 12.4 ± 4.1 vs. 4.4 ± 11.2, P = 0.02). Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus. Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 ± 0.29).
Conclusion
Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.
5.Erratum: Induction of apoptotic cell death in human bladder cancer cells by ethanol extract of Zanthoxylum schinifolium leaf, through ROSdependent inactivation of the PI3K/ Akt signaling pathway
Cheol PARK ; Eun Ok CHOI ; Hyun HWANGBO ; Hyesook LEE ; Jin-Woo JEONG ; Min Ho HAN ; Sung-Kwon MOON ; Seok Joong YUN ; Wun-Jae KIM ; Gi-Young KIM ; Hye-Jin HWANG ; Yung Hyun CHOI
Nutrition Research and Practice 2025;19(2):328-330
6.Development of automatic organ segmentation based on positron-emission tomography analysis system using Swin UNETR in breast cancer patients in Korea
Dong Hyeok CHOI ; Joonil HWANG ; Hai-Jeon YOON ; So Hyun AHN
The Ewha Medical Journal 2025;48(2):e30-
Purpose:
The standardized uptake value (SUV) is a key quantitative index in nuclear medicine imaging; however, variations in region‐of‐interest (ROI) determination exist across institutions. This study aims to standardize SUV evaluation by introducing a deep learning‐based quantitative analysis method that enhances diagnostic and prognostic accuracy.
Methods:
We used the Swin UNETR model to automatically segment key organs (breast, liver, spleen, and bone marrow) critical for breast cancer prognosis. Tumor segmentation was performed iteratively based on predefined SUV thresholds, and prognostic information was extracted from the liver, spleen, and bone marrow (reticuloendothelial system). The artificial intelligence training process employed 3 datasets: a test dataset (40 patients), a validation dataset (10 patients), and an independent test dataset (10 patients). To validate our approach, we compared the SUV values obtained using our method with those produced by commercial software.
Results:
In a dataset of 10 patients, our method achieved an auto‐segmentation accuracy of 0.9311 for all target organs. Comparison of maximum SUV and mean SUV values from our automated segmentation with those from traditional single‐ROI methods revealed differences of 0.19 and 0.16, respectively, demonstrating improved reliability and accuracy in whole‐organ SUV analysis.
Conclusion
This study successfully standardized SUV calculation in nuclear medicine imaging through deep learning‐based automated organ segmentation and SUV analysis, significantly enhancing accuracy in predicting breast cancer prognosis.
7.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.
8.Environmental disease monitoring by regional Environmental Health Centers in Korea: a narrative review
Myung-Sook PARK ; Hwan-Cheol KIM ; Woo Jin KIM ; Yun-Chul HONG ; Won-Jun CHOI ; Seock-Yeon HWANG ; Jiho LEE ; Young-Seoub HONG ; Yong-Dae KIM ; Seong-Chul HONG ; Joo Hyun SUNG ; Inchul JEONG ; Kwan LEE ; Won-Ju PARK ; Hyun-Joo BAE ; Seong-Yong YOON ; Cheolmin LEE ; Kyoung Sook JEONG ; Sanghyuk BAE ; Jinhee CHOI ; Ho-Hyun KIM
The Ewha Medical Journal 2025;48(1):e3-
This study explores the development, roles, and key initiatives of the Regional Environmental Health Centers in Korea, detailing their evolution through four distinct phases and their impact on environmental health policy and local governance. It chronicles the establishment and transformation of these centers from their inception in May 2007, through four developmental stages. Originally named Environmental Disease Research Centers, they were subsequently renamed Environmental Health Centers following legislative changes. The analysis includes the expansion in the number of centers, the transfer of responsibilities to local governments, and the launch of significant projects such as the Korean Children’s Environmental Health Study (Ko-CHENS ). During the initial phase (May 2007–February 2009), the 10 centers concentrated on research-driven activities, shifting from a media-centered to a receptor-centered approach. In the second phase, prompted by the enactment of the Environmental Health Act, six additional centers were established, broadening their scope to address national environmental health issues. The third phase introduced Ko-CHENS, a 20-year national cohort project designed to influence environmental health policy by integrating research findings into policy frameworks. The fourth phase marked a decentralization of authority, empowering local governments and redefining the centers' roles to focus on regional environmental health challenges. The Regional Environmental Health Centers have significantly evolved and now play a crucial role in addressing local environmental health issues and supporting local government policies. Their capacity to adapt and respond to region-specific challenges is essential for the effective implementation of environmental health policies, reflecting geographical, socioeconomic, and demographic differences.
9.The Enhancement of Line Operations Safety Audit for Safe Flight Operation
Korean Journal of Aerospace and Environmental Medicine 2025;35(1):4-7
Purpose:
Line Operations Safety Audit (LOSA) has reduced errors by detecting and managing threats and errors of flight deck crew in the cockpit during normal flight operations. Airlines can understand the countermeasures and competencies of the crew and the success of error management. This paper introduces the advantages of LOSA and how LOSA data collection can be enhanced for the safety of flight operations.
Methods:
It analyzed the components of data collection tool in the International Civil Aviation Organization Doc 9803, LOSA manual to find out the deficiencies for enhancement.
Results:
Five suggestions are proposed in this study, codes for positive activities and the development of a form, the development of proactive strategies that predict threats in advance and manage the threats and management of errors, to describe the coding and narrative for successful briefings that manage threats and errors and codes for positive culture are required for successful LOSA data collection flight operations.
Conclusion
Safety Management System, Threat and Error Management, LOSA, and other conventional safety tools manage safety based on risk or failure, so if we change the paradigm, we can train more safety-resilient pilots. The tragic outcomes such as accidents or incidents have the problem of low occurrence probability, but if we supplement and utilize LOSA data of normal flights, we can prevent accidents or nearaccidents in advance.
10.Mortality and Risk Factors for Emphysematous Pyelonephritis in Korea: A Multicenter Retrospective Cohort Study
Seung-Kwon CHOI ; Jeong Woo LEE ; Seung Il JUNG ; Eu Chang HWANG ; Joongwon CHOI ; Woong Bin KIM ; Jung Sik HUH ; Jin Bong CHOI ; Yeonjoo KIM ; Jae Min CHUNG ; Ju-Hyun SHIN ; Jae Hung JUNG ; Hong CHUNG ; Sangrak BAE ; Tae-Hyoung KIM
Urogenital Tract Infection 2025;20(1):34-41
Purpose:
Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN.
Materials and Methods:
Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods.
Results:
The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%).
Conclusions
EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.

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