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.A Practical Immunohistochemistry-Based Model for Predicting Pathologic Complete Response in Estrogen Receptor-Strong Positive and HER2-Negative Breast Cancer
Su Min LEE ; Jeong Eon LEE ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Eun Yoon CHO ; Hyunwoo LEE ; Woong Ki PARK
Journal of Breast Cancer 2026;29(2):128-140
Purpose:
While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer.
Methods:
Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses.
Results:
Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups.
Conclusion
This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.
3.Fully automated artificial intelligence– based echocardiographic analysis substantially reduces workflow time while preserving measurement accuracy: a pilot study
Jonghee SUN ; Yeonyee E. YOON ; Jiyeon LEE ; Ganghan LEE ; Minjung BAK ; Jiesuck PARK ; Hong‑Mi CHOI ; In‑Chang HWANG ; Goo‑Yeong CHO
Journal of Cardiovascular Imaging 2026;34(1):10-
Background:
Transthoracic echocardiography (TTE) requires time-intensive integration of quantitative measure‑ ments and qualitative visual assessment. Fully automated artificial intelligence (AI)-based analysis may reduce total analysis time while preserving accuracy, but systematic real-world validation remains limited.
Methods:
This prospective, single-center pilot study enrolled 40 TTE examinations. Identical deidentified DICOM datasets were independently provided to a trained cardiac sonographer and a fully automated AI system comprising quantitative and qualitative visual interpretation modules. All outputs were compared with a cardiologist-adjudicated reference standard. Primary endpoints were total analysis time and noninferiority of AI-derived left ventricular ejection fraction (LVEF) versus the reference standard, with a prespecified margin of 3 percentage points (one-sided α = 0.025).
Results:
Median analysis time was 94 s (interquartile range [IQR], 82–106 s) for the AI workflow versus 490 s (IQR, 438–626 s) for the human workflow (P < 0.001). AI-derived LVEF met the noninferiority criterion (mean difference, 0.00 percentage points; upper one-sided 95% confidence bound, 1.41 percentage points; P < 0.001), with an intraclass correlation coefficient (ICC) of 0.902 (95% confidence interval, 0.822–0.947). ICCs for secondary quantitative indi‑ ces ranged from 0.625 to 0.989. For aortic regurgitation severity grading, AI’s overall accuracy was 75.0% (quadratic weighted κ = 0.762), compared with 82.5% for human interpretation (κ = 0.812, McNemar P = 0.579).
Conclusions
Fully automated AI-assisted TTE analysis substantially reduced total analysis time while maintaining noninferior LVEF accuracy and acceptable performance across secondary quantitative and qualitative indices. These findings support the use of AI as a practical workflow accelerator in routine echocardiography.
4.Spontaneous and simultaneous bilateral middle meningeal arteriovenous fistula: A case report
Gi-Yong YUN ; Jae-Min AHN ; Jong-Hyun PARK ; Hyuk-Jin OH ; Jai-Joon SHIM ; Seok-Mann YOON
Journal of Cerebrovascular and Endovascular Neurosurgery 2026;28(1):49-56
Middle meningeal arteriovenous fistulas (MMAVFs) are known as rare diseases, often associated with head trauma, with idiopathic cases being exceedingly uncommon. Here, we present a clinical case of spontaneous and simultaneous bilateral MMAVFs in a 37-year-old woman. She presented with persistent pulsatile tinnitus but no history of head trauma. Bilateral MMAVFs were identified via Time-of-Flight Magnetic Resonance Angiography. Subsequent digital subtraction angiography revealed a fistula between the middle meningeal artery (MMA) and middle meningeal vein (MMV) without definite intracranial venous reflux. We had planned coil embolization via a trans-arterial approach for both sides. Remarkably, after six days, the right-sided MMAVF observed in the previous external carotid artery (ECA) angiogram disappeared spontaneously. The left-sided MMAVF was successfully treated with coil embolization, achieving complete obliteration of fistula flow. Postoperatively, the patient’s pulsatile tinnitus disappeared, and she was discharged without medication. There are a few possible mechanisms of spontaneous MMAVFs, such as middle meningeal artery aneurysm and trivial head trauma. Trans-arterial embolization with coils appears to be an effective and safe treatment option for complete obliteration of fistula flow.
5.Evaluation of a Vietnamese medical school using Korean medical school accreditation standards
Bo-Young YOON ; Yon-Chul PARK ; Keunmi LEE ; Hee-Je LEE ; Jung-Sook HA ; Seung-Jae HONG ; Nguyen Hoang MINH ; Jung-Sik HUH
Journal of Medicine and Life Science 2026;23(1):24-32
The global shortage of healthcare personnel, especially in low- and middle-income countries, has raised concerns about the quality and availability of medical education across these economies. Therefore, standardization and accreditation of medical education are essential to ensure the competence of healthcare professionals. This study reports the first-ever application of the set of standards developed by the Korean Institute of Medical Education and Evaluation (KIMEE) to assess a Vietnamese medical school. Under this initiative, the Accreditation Standards of KIMEE 2019 (ASK 2019) was implemented under the auspices of a Korea International Cooperation Agency Development Project. This study compared the evaluation results of a Vietnamese medical school’s performance with that of accredited Korean medical schools. The findings revealed both strengths and areas requiring significant improvement and underscore the need for Vietnam to develop its own contextually appropriate accreditation system.
6.Psychometric Properties of the Mixed State Severity Index for Patients With Mood Disorder
Woojae MYUNG ; Hyeona YU ; Hyo Shin KANG ; Daseul LEE ; Junwoo JANG ; Jakyung LEE ; Joohyun YOON ; Yun Seong PARK ; Hyun A RYOO ; Ye Rim KIM ; Kwang Ho PARK ; Chan Woo LEE ; Yoonjeong JANG ; Kimyoung KIM ; Nara LEE ; Sanghoon HONG ; Hong-Hee WON ; Tae Hyon HA ; Jungkyu PARK
Psychiatry Investigation 2026;23(1):106-117
Objective:
This study aimed to develop a reliable and valid Mixed State Severity Index (MSSI) to assess mood instability in patients with mood disorders and determine cutoff scores.
Methods:
Twenty-one items were selected based on Koukopoulos’ criteria for mixed depressive episode, historically referred to as agitated depression, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision mixed features criteria. The MSSI was administered to 242 patients (major depressive disorder [n=92], bipolar disorder [BD] I [n=78], and BD II [n=72]) and 726 controls.
Results:
The MSSI demonstrated high internal consistency (α=0.78–0.90). Exploratory factor analysis revealed a stable four-factor structure. Based on receiver operating characteristic analysis, optimal cutoff scores were identified to distinguish mood disorder groups from controls, ranging from 19.5 to 27.5 depending on diagnosis.
Conclusion
The MSSI is a reliable and valid instrument for assessing the severity of mixed features in patients with mood disorders. The established cutoff scores enhance its clinical utility, providing robust diagnosis and treatment planning support.
7.Risk of Psychiatric Morbidity in People Living With Human Immunodeficiency Virus: A Population-Based Cohort Study
Tak Kyu OH ; Kyoung-Ho SONG ; Eunjeong HEO ; Hye Yoon PARK ; In-Ae SONG
Psychiatry Investigation 2026;23(1):38-47
Objective:
The incidence of psychiatric illnesses might be higher in individuals people living with human immunodeficiency virus (PLWH) than in individuals without human immunodeficiency virus (HIV). We aimed to investigate whether PLWH had different risks of psychiatric morbidities in comparison to non-HIV-infected individuals.
Methods:
This study included all PLWH in South Korea between January 1, 2017 and December 31, 2017. The control group, which had never been diagnosed with HIV, was selected using a 1:10 stratified random sampling technique, considering age and sex. The endpoint of this study was new diagnosis of psychiatric morbidities which were diagnosed from January 1, 2018 to December 31, 2022.
Results:
After conducting a 1:5 propensity score (PS) matching process, the final analysis comprised a group of 17,815 PLWH and 78,021 control subjects. In the PS-matched cohort, the incidence rate of psychiatric morbidity in PLWH was 5,677.7 per 100,000 per year, whereas that in the controls was 4,926.3 per 100,000 per year. In Cox regression in the PS-matched cohort, PLWH showed 17% (hazard ratio, 1.17; 95% confidence interval, 1.14–1.21; p<0.001) higher risk of psychiatric morbidity than controls. Specifically, PLWH showed higher risk of depression, mania, bipolar disorder, insomnia disorder, substance use disorder, and schizophrenia compared to controls.
Conclusion
PLWH had a greater likelihood of experiencing psychiatric morbidities compared to those without HIV in South Korea. Our research findings indicate the importance of public health policy in addressing the declining mental health of individuals living with HIV.
8.Occupational Exposure Risk and Safety of Novel IntraperitonealOxaliplatin Delivery via Heated CO 2 and Dual-flow Nozzle System
Soyeon LEE ; Jongmin PARK ; Myoungho LEE ; Mira YOO ; Chanmi BANG ; Sungho HWANG ; Dukyeon KIM ; Soo Kyung BAE ; Hyungho KIM ; Chungsik YOON
Safety and Health at Work 2026;17(1):127-133
Background:
Peritoneal carcinomatosis is challenging to treat, with poor prognosis. Although pressurized intraperitoneal aerosol chemotherapy (PIPAC) and hyperthermal PIPAC (HPIPAC) aim to improve patients’ quality of life, there is a potential risk of antineoplastic drug exposure to healthcare workers during surgery. This study evaluates the risk of oxaliplatin exposure among healthcare workers during PIPAC and HPIPAC compared to systemic intravenous chemotherapy (IV).
Methods:
Oxaliplatin was administered to a swine model via IV, PIPAC, and HPIPAC in the operating room. Surface samples (n = 484) were collected from the operating room and personal protective equipment (PPE), while air samples (n = 144) were taken near the respiratory tract. Platinum, as an indicator of oxaliplatin, was measured using inductively coupled plasma mass spectrometry (ICP-MS).
Results:
Platinum was undetectable in 98.6% of the air samples, except one PIPAC leakage case. Surface contamination occurred in 8.7% of room samples and 13.9% of PPE, with gloves being most affected.Platinum contamination was also found on instruments like endoscope cameras and injectors, and cross-contamination on floors and injectors before PIPAC indicated suboptimal cleaning. No platinum was detected in the experimenter’s blood and urine.
Conclusion
Airborne platinum exposure was minimal when no drug leakage occurred, but surface contamination, particularly on gloves and instruments, highlighted the need for stringent protective measures to reduce occupational exposure risk. Although the possibility of inhalation exposure was low and there are no legal exposure standards for oxaliplatin, precautions should be taken to avoid potential exposure.
9.Pressure Changes at the Fifth Metatarsal Regions during Running with Different Foot Strike Patterns
Ji Hwan PARK ; Jin Su KIM ; Jae Keun OH ; Jin Ho YOON
The Korean Journal of Sports Medicine 2026;44(1):49-59
Purpose:
This study aimed to analyze changes in plantar pressure distribution at the fifth metatarsal (M5) during running with different foot strike patterns.
Methods:
Thirty-five healthy adults ran barefoot over a foot scan pressure plate installed in a 10-m shuttle walkway.Each participant completed 10 trials per strike pattern and mean peak pressures at M1–M5 heads and M5 base of the dominant foot was analyzed.
Results:
The mean peak pressures at M2– M5 heads increased progressively from heel to midfoot to forefoot strike (p< 0.05). Significant differences among strike patterns were found at M2–M5 heads (p< 0.05). Post hoc analysis showed that forefoot strike produced significantly higher pressures at M2–M5 heads than heel and midfoot strikes (p< 0.001). At M5, peak pressure at the head increased from heel (14.54±7.82) to midfoot (15.54±7.75) to forefoot strike (19.37±7.37), whereas peak pressure at the base decreased from heel (6.27±1.69) and midfoot strikes (5.85±1.94) to forefoot strike (4.35±1.79). At M5, both the head and base demonstrated significant differences according to strike pattern.
Conclusion
Plantar pressure patterns vary across foot strike types, with forefoot strike producing greater M5 head loading but lower base loading. These findings suggest that forefoot-based low-intensity running may be considered as an early loading option during rehabilitation after Jones fractures, although further clinical studies are needed to confirm its clinical benefits.
10.‘Jayulsingyeongsiljo’ Is Not a Recognized Medical Term: 2025 Survey of the Korean Society of Pain and Autonomic Disorders
Kyomin CHOI ; Jeeyoung OH ; Jin-Woo PARK ; Byeol-A YOON ; Eun Bin CHO ; Tae-Kyeong LEE
Journal of the Korean Neurological Association 2026;44(1):37-46
Background:
To investigate Korean neurologists' perceptions of the non-standard term ‘jayulsingyeongsiljo’ and their actual evaluation and management of such patients.
Methods:
We performed an anonymous web-based cross-sectional survey of board-certified Korean neurologists by Korean Society of Pain and Autonomic Disorders between August 13 and September 10, 2025. A questionnaire sent by e-mail asked about demographics, experience with patients labeled with ‘jayulsingyeongsiljo,’ use and perceived usefulness of autonomic function tests, the impact of coronavirus disease 2019, and opinions on terminology and the role of neurologists.
Results:
In total, 109 neurologists responded. Most reported that patients presenting for ‘jayulsingyeongsiljo’ were young or middle-aged adults and that their numbers had increased over the preceding 2 years. Referrals frequently originated from Korean medicine clinics and other non-neurology departments, often after stand-alone heart rate variability testing. Fatigue, orthostatic intolerance, palpitations, sweating abnormalities, gastrointestinal symptoms, and anxiety or insomnia were common, and autonomic testing was generally regarded as helpful. Eighty percent felt that the risks associated with ‘jayulsingyeongsiljo’ are overstated, and 95% preferred replacing the term with standardized expressions such as autonomic dysfunction.
Conclusions
Korean neurologists view ‘jayulsingyeongsiljo’ as an unrecognized and potentially misleading label and support society-led standardization of terminology and guidance to improve autonomic dysfunction care and resource use.

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