1.Segmentation-Based Landmark Localization in Cerebral Magnetic Resonance Angiography Using Landmark Subsets
Yura JEONG ; Daehyun KWON ; Se-On KIM ; Ga-Hyeon KIM ; Min-Seo PARK ; Yoon-Chul KIM
Investigative Magnetic Resonance Imaging 2026;30(1):11-19
Purpose:
The accurate localization of bifurcation points in the brain near the circle of Willis is essential for labeling cerebral arteries and detecting potential aneurysms. Studies on the development of segmentation-based landmark localization methods for cerebral angiography are lacking. This study aimed to develop and validate a method for localizing anatomical landmarks using a three-dimensional (3D) encoder-decoder deep convolutional neural network architecture.
Materials and Methods:
Time-of-flight magnetic resonance angiography (MRA) images of 224 subjects obtained from publicly available datasets were used. Ten anatomical landmark points were annotated, and four different landmark subset configurations were trained and validated. For each configuration, 3D U-Net-based models were developed using the MRA images and their corresponding annotated landmarks. The deep learning prediction results were evaluated in terms of landmark localization errors.
Results:
Among the four configurations, the configuration with five landmark subsets produced the smallest landmark localization errors in the test dataset. Post-processing of the U-Net-predicted segmentation masks further reduced the mean localization errors across all landmark points for the configuration with five subsets.
Conclusion
The proposed landmark localization method effectively identified major anatomical landmarks around the circle of Willis and showed the potential to automate segmental analyses of intracranial arterial tortuosity.
2.Detection and prognostic stratification of left ventricular systolic dysfunction in left bundle branch block using an artificial intelligence–enabled electrocardiography
Soo Youn LEE ; Ah‑Hyun YOO ; Sora KANG ; Jong‑Hwan JANG ; Yong‑Yeon JO ; Jeong Min SON ; Min Sung LEE ; Ga In HAN ; Joon‑myoung KWON ; Hak Seung LEE ; Kyung‑Hee KIM
Journal of Cardiovascular Imaging 2026;34(1):4-
Background:
Left bundle branch block (LBBB) significantly increases the risk of left ventricular systolic dysfunction (LVSD) due to cardiac dyssynchrony. Although artificial intelligence–enabled electrocardiography (AI-ECG) mod‑ els show promise in detecting LVSD, their performance in LBBB patients remains underexplored. We hypothesized that an AI-ECG model clinically validated for detecting LVSD would accurately detect LVSD and predict future clinical outcomes in LBBB patients.
Methods:
In this retrospective multicenter study, 5,689 expert-validated LBBB ECGs collected from 2,813 patients between 2016 and 2024 were analyzed using a previously developed and validated AI-ECG model. LVSD was defined as an ejection fraction of ≤ 40%. Model performance was assessed using the area under the receiver operating char‑ acteristic curve (AUROC), the area under the precision-recall curve (AUPRC), sensitivity, and specificity. Patients were stratified into high- and low-risk groups based on a threshold that achieved 90% sensitivity. A Kaplan–Meier analysis was used to compare clinical outcomes.
Results:
Among the 2,813 LBBB patients (mean age, 70.7 years; male sex, 43.7%), hypertension and a history of heart failure were common. The AiTiALVSD model showed strong diagnostic performance for LVSD (AUROC, 0.930 [95% CI, 0.924–0.937]; AUPRC, 0.913 [95% CI, 0.902–0.923]; sensitivity, 0.979; specificity, 0.473). During the mean follow-up of 4.1 years, high-risk patients had significantly higher hazards than low-risk patients for all-cause mortality (adjusted hazard ratio [HR], 1.87; 95% CI, 1.53–2.28), implantable cardioverter defibrillator/cardiac resynchronization therapy implantation (adjusted HR, 15.2; 95% CI, 7.51–30.77), and cardiovascular hospitalization (adjusted HR, 1.11; 95% CI, 0.96–1.28).
Conclusions
AiTiALVSD effectively detects LVSD and stratifies long-term cardiovascular risk in LBBB patients, support‑ ing its clinical utility for early detection and patient management.
3.Comparative survival outcomes of surgical resection versus radiotherapy after FOLFIRINOX in borderline resectable and locally advanced pancreatic cancer
Jiwon YU ; Jeong Ha LEE ; Hyunju SHIN ; Hee Chul PARK ; Joon Oh PARK ; Jung Yong HONG ; Minsuk KWON ; Ji Eun SHIN ; Kyu Taek LEE ; Kwang Hyuck LEE ; Jong Kyun LEE ; Joo Kyung PARK ; Young Hoon CHOI ; Jin Seok HEO ; In Woong HAN ; Sang Hyun SHIN ; Hongbeom KIM ; Ji Hye MIN ; Jeong Il YU
Precision and Future Medicine 2026;10(1):39-50
Purpose:
This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control.
Methods:
We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR.
Results:
Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37).
Conclusion
Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.
4.Secondary transmission of severe fever with thrombocytopenia syndrome in a hospital setting in Republic of Korea: a retrospective observational study of personal protective equipment use and infection risk factors
Seongwoo PARK ; Hye Young LEE ; Jeong-ran KWON ; Yuna KIM
Osong Public Health and Research Perspectives 2026;17(2):155-164
Objectives:
This study investigated a cluster of secondary human-to-human transmission of severe fever with thrombocytopenia syndrome (SFTS) in a hospital setting, focusing on infection risk factors and the role of personal protective equipment (PPE).
Methods:
A descriptive epidemiological investigation was conducted following the death of anindex patient with laboratory-confirmed SFTS. A total of 27 close contacts, including healthcareworkers and a funeral director, were monitored for symptoms. Suspected cases underwent real-time reverse transcription polymerase chain reaction testing. Clinical features, PPE use, and exposure histories were analyzed. The Fisher exact test was used to assess associations between PPE use and infection. Viral genotyping and sequence analyses were performed to evaluate transmission routes.
Results:
The index patient deteriorated rapidly and died after repeated cardiopulmonaryresuscitation (CPR), during which 8 secondary cases occurred. Most infections were identifiedamong individuals involved in CPR or postmortem care without adequate PPE. Although notstatistically significant, infection rates were higher among those who did not wear masks or who used low-filtration masks. Proper use of gloves, gowns, and goggles was associated withlower infection rates. Cycle threshold values in secondary cases (range, 34–39) were higherthan in the index case (14.07), suggesting lower viral loads. Sequence analysis demonstrated99.6%–100% homology between the index and secondary cases; all isolates were genotype B, indicating direct transmission.
Conclusion
This study provides molecular and epidemiological evidence of nosocomial SFTS transmission. Inadequate PPE use during aerosol-generating procedures likely facilitated infection, underscoring the importance of strict adherence to PPE protocols and reinforced infection control practices.
5.Antifungal Effects of Non-Thermal Atmospheric Pressure Plasma In Vitro and Ex Vivo
Hye-Jin AHN ; Jin-Woo LEE ; Woo Yeon HWANG ; Byung Su KWON ; Ki-Heon JEONG ; Min Kyung SHIN
Annals of Dermatology 2026;38(2):98-107
Background:
Non-thermal atmospheric pressure plasma (NTAP) generates reactive oxygen species, reactive nitrogen species, and ultraviolet radiation, which can inactivate microorganisms.Onychomycosis treatment is challenging, and its prognosis is poor owing to mixed infections and dermatophytosis. Although NTAP has shown in vitro antifungal effects against dermatophytes and yeast, its efficacy against non-dermatophyte molds (NDMs) and in clinical or nail model studies remains poorly understood.
Objective:
We evaluated the effects of NTAP on fungi, including NDMs, and infected nail plates.
Methods:
For the in vitro experiments, Trichophyton rubrum, Candida albicans, Aspergillus fumigatus, and Fusarium oxysporum strains were exposed to NTAP. After NTAP exposure (2,4 and 6 minutes), growth curve, cell viability, and biofilm biomass were assessed by absorbance wavelength of 600 nm, XTT assay, and crystal violet staining, respectively. For the ex vivo experiments, infected nail plates were analyzed using a scanning electron microscope.
Results:
T. rubrum and C. albicans showed greater growth inhibition with increasing NTAP exposure time, whereas A. fumigatus showed enhanced growth after 6 minutes exposure. Many fungal elements within the subungual hyperkeratosis of the ex vivo specimen were all damaged following NTAP exposure.
Conclusion
NTAP has antifungal effects on dermatophytes, yeast, and NDMs. We suggest that the intensity and time of NTAP application should be adjusted according to each strain and can be more effective when NTAP directly reaches the hyphae on the nail bed or subungual hyperkeratosis.
6.Accuracy of Two Direct Antibiotic-Susceptibility Tests and Their Impact on the Optimal Treatment of Enterobacterales-Associated Bloodstream Infection:Comparison of the QMAC-dRAST V2.5 and BD Phoenix M50 Systems
Ji Sang YOON ; Joo An KWON ; Jeong Seob SHIN ; Hyun Soo SEOK ; In Young YOO ; Yeon-Joon PARK
Annals of Laboratory Medicine 2026;46(3):279-288
Background:
Rapid pathogen identification and antibiotic-susceptibility tests (ASTs) are important for treating bloodstream infections. We compared the performance of the QMAC-dRAST and BD Phoenix M50 direct AST (dPhoenix) systems using bacterial pellets prepared from positive blood culture broth and evaluated their impact on treatment modification.
Methods:
Direct AST results for 106 Enterobacterales isolates were retrospectively reviewed. Conventional broth microdilution was used to calculate categorical agreement (CA), very major error (VME), major error (ME), and minor error (mE). For isolates showing high VMEs in both methods, supplementary tests were performed. Clinical impact was evaluated by calculating the time required to obtain AST results (time-to-result) and observing changes in antibiotics prescribed after performing ASTs.
Results:
Both systems showed acceptable overall CA, VME, ME, and mE values (QMACdRAST: 93.6%, 1.6%, 0.9%, and 5.3%, respectively; dPhoenix: 93.1%, 0.9%, 0.6%, and 6.2%, respectively). Piperacillin–tazobactam showed high VMEs with QMAC-dRAST (4/20, 20.0%) and dPhoenix (3/20, 15.0%). Colony AST on 13 isolates revealed that QMACdRAST testing yielded lower minimal inhibitory concentrations (MICs) for piperacillin–tazobactam with three isolates, whereas dPhoenix testing yielded higher MICs with two isolates and lower MICs with two isolates. The average time-to-result was 20.8 hr and 30.1 hr for QMAC-dRAST and dPhoenix, respectively (P < 0.001). After AST, the number of optimal treatments increased from 43 (46.7%) to 72 (78.3%) (P < 0.001).
Conclusions
The QMAC-dRAST and dPhoenix systems provided reliable AST results with a short time-to-result. However, we recommend performing complementary tests, such as the disk diffusion test, for piperacillin–tazobactam.
7.Obstetric Outcomes of Jehovah’s Witness Women Under Patient Blood Management: A Single-center, Propensity Score–Matched Cohort Study in Korea
Jeong-Won OH ; Seug Yun YOON ; Jeong Jae LEE ; Kyu Yeon CHOI ; Seong Soon KWON
Journal of Preventive Medicine and Public Health 2026;59(2):143-151
Objectives:
Patient blood management (PBM) is increasingly recognized as an essential strategy in obstetric care for reducing transfusion-related risks and improving maternal safety. Jehovah’s Witness (JW) women, who categorically refuse blood transfusion, represent a unique clinical population in which to evaluate the effectiveness of PBM. This study aimed to assess obstetric outcomes of JW women compared with non-JW women at a PBM-based center in Korea.
Methods:
We retrospectively reviewed delivery outcomes and PBM practices among JW women (n=205) with singleton pregnancies and non-JW women (n=601) who were matched at a 1:3 ratio using propensity scores at Soonchunhyang University Seoul Hospital between 2018 and 2023. The primary outcomes included obstetric morbidities, with particular attention to complications related to postpartum hemorrhage and the interventions used for its management.
Results:
JW women were more likely to receive intravenous iron administration (7.3 vs. 2.8%, p=0.008) and had higher hemoglobin (Hb) levels during the first trimester (12.6±1.1 vs. 11.8±3.4 g/dL, p=0.012) than non-JW women. Blood loss during cesarean section and the incidence of severe postpartum anemia (Hb <7 g/dL) were lower among JW women; however, these differences did not reach statistical significance. In the hemorrhage-related high-risk subgroup, JW women were managed according to PBM protocols without transfusion, and their obstetric outcomes were comparable to those observed in non-JW women.
Conclusions
This study identified no significant differences in hemorrhage-related obstetric outcomes between JW and non-JW women at a PBM-based center. The systematic application of PBM enables safe delivery in transfusion-restricted settings and may reduce reliance on blood transfusion while maintaining maternal safety.
8.The Emerging Patterns of New Psychoactive Substance–Related Fatalities in South Korea: A Retrospective Study of Forensic Autopsy Cases
Sohyung PARK ; Han Na KIM ; Youngjin JEON ; Minjung KIM ; Seon Jung JANG ; Jeong Hwa KWON
Korean Journal of Legal Medicine 2026;50(2):39-52
New psychoactive substances (NPS) have rapidly emerged in illicit drug markets worldwide and are increasingly encountered in postmortem examinations. However, postmortem data on NPS-related deaths remain limited worldwide. This study describes postmortem findings from forensic autopsy cases in which NPS were detected and explores the characteristics of these deaths through a retrospective review. Six postmortem cases were identified between 2023 and 2024. The cases predominantly involved young adults. Toxicological analysis identified synthetic cannabinoids, dissociatives, and a stimulant, either alone or in combination with alcohol or conventional illicit drugs such as methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Drug paraphernalia or a documented history of drug use was identified in only some cases. The causes of death included acute intoxication and traumatic deaths in which drug intoxication may have contributed to abnormal behavior and fatal outcomes. These findings provide preliminary forensic evidence of the emergence of NPS in South Korea. They underscore the importance of postmortem examination with comprehensive toxicological screening and continued surveillance of emerging psychoactive substances in forensic practice. They also suggest the value of reviewing a history of prior substance use even in unexpected sudden deaths not initially suspected to be drugrelated.
9.Prospective Evaluation of Irreversible Electroporation With Clustered Electrodes as a Novel Palliative Approach for Locally Advanced Pancreatic Cancer
Joon Ho KWON ; Man-Deuk KIM ; Maher Salamah ALANAZI ; Jiwon SUK ; Seung JEONG ; Seungmin BANG ; Moon Jae CHUNG ; Ho Kyoung HWANG ; Seung Soo HONG ; Kichang HAN ; Gyoung Min KIM ; Jong Yun WON ; Juil PARK ; Jaesung CHO ; Seok Min JEONG ; Tae Yang CHOI
Korean Journal of Radiology 2026;27(2):152-160
Objective:
This study aimed to evaluate the feasibility, safety, and oncologic outcomes of irreversible electroporation (IRE) using a clustered electrode in patients with locally advanced pancreatic cancer (LAPC).
Materials and Methods:
In this single-center prospective cohort study, 13 patients with LAPC (median age, 60 years; range, 48–78 years) underwent clustered electrode IRE between September 2022 and September 2024. Patient characteristics, procedural details, and clinical outcomes were recorded. Endpoints included technical success, procedure-related complications, overall survival (OS), and progression-free survival (PFS).
Results:
Tumors were located in the pancreatic head in four patients (30.8%) and in the body/tail in nine (69.2%). The median tumor size was 2.4 cm (1.5–4.0 cm), and vascular invasion was present in all patients. Technical success was achieved in all patients. Intraoperative IRE was performed in 11 (84.6%) patients, and 2 (15.4%) patients underwent percutaneous IRE. Gastrointestinal bleeding events as major complications occurred in two patients (15.4%) and, both were successfully controlled by embolization. No 60-day mortality was observed. At a median follow-up of 24.5 months (range, 9.9–33.4 months) after IRE, median OS and PFS from IRE were 20.1 and 14.5 months, respectively.
Conclusion
IRE using clustered electrodes for LAPC appears to be a feasible therapeutic approach, offering reliable technical success and acceptable safety. Survival outcomes are encouraging; however, larger, controlled studies are required.
10.Development and Validation of an Analytical Method for the Simultaneous Determination of Three Marker Compounds in Wikstroemia trichotoma
Min-Ji KEEM ; Taek-Hwan KWON ; Beom-Geun JO ; Sangho CHOI ; Jin-Hyub PAIK ; Young Suk JUNG ; Eun-Ju JEONG ; Su-Nam KIM ; Min Hye YANG
Natural Product Sciences 2026;32(1):84-92
The Wikstroemia genus is highly regarded in traditional Asian medicine for its diverse therapeutic applications, including the treatment of inflammatory and infectious conditions. Among its members,Wikstroemia trichotoma (Thunb.) Makino remains a promising medicinal resource which is yet to be chemicallycharacterized. To ensure the chemical consistency of W. trichotoma, we developed and validated the first HPLC method for the simultaneous quantification of three major marker compounds: chlorogenic acid (1), miconioside B (2), and matteucinol 7-O-apiofuranosyl(1→6)-glucopyranoside (3). Chromatographic separation was achieved on a C18 column using a gradient elution system of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Detection was optimized using a photodiode array (PDA) detector at 280 and 325 nm, based on the absorption maxima of the markers. The method was validated in accordance with the International Council for Harmonisation (ICH) and the Ministry of Food and Drug Safety (MFDS) guidelines. The results demonstrated high linearity (r2 > 0.999), with limits of detection and quantitation ranging from 4.28–6.42 and 12.97–19.47 μg/ mL, respectively. Intra- and inter-day precision (% RSD ≤ 1.83%) and accuracy (recoveries of 92.5–101.7%) were within acceptable limits. Quantitative analysis revealed the contents of 1, 2, and 3 in the W. trichotoma extract to be 19.9, 139.8, and 264.9 mg/g, respectively. This study provides a reliable analytical framework for the standardization, quality control, and future pharmacological evaluation of W. trichotoma.

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