1.A Comparison between Keratograph 5M® and IDRA® in Dry Eye Patients
Seo Woo PARK ; Ha-Rim SO ; Ji Won BAEK ; Ho Sik HWANG ; Kyung-Sun NA ; Ho RA ; Nam Yeo KANG ; Hyun Seung KIM ; Eun Chul KIM
Journal of the Korean Ophthalmological Society 2025;66(4):175-180
Purpose:
To evaluate the compatibility and usability of test results obtained from the IDRA and Keratograph 5M in clinical settings by comparing their performance in patients with dry eye disease.
Methods:
From December 27 to 30, 2022, a study was conducted on 30 patients diagnosed with dry eye utilizing both the Keratograph 5M and IDRA devices. The parameters compared and analyzed included lipid layer thickness, tear meniscus height, tear film break-up time, and meibography. A paired t-test was used for statistical comparison. The lipid layer thickness in the Keratograph 5M was graded on a scale from 0 to 4 based on thickness.
Results:
No significant differences were found between the two devices in tear film break-up time, tear meniscus height, and meibography (p = 0.148, 0.072, 0.124, respectively). However, the tear lipid layer thickness measured by IDRA showed a proportional relationship with the grade assigned by the Keratograph 5M (Kendall R = 0.217, p = 0.037; Spearman R = 0.260, p = 0.045).
Conclusions
The IDRA device offers the advantage of performing multiple dry eye tests; simultaneously, thereby saving time compared to the Keratograph 5M. Both devices can be used compatibly with IDRA particularly advantageous for providing a numerical value for tear lipid layer thickness which enhances the convenience of dry eye diagnosis and treatment.
2.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.
3.Risk of Biliary Tract and Pancreatic Cancer Following Obstructive Sleep Apnea Diagnosis: Analysis of a National Health Insurance Database
Marn Joon PARK ; Gyu Tae KIM ; Seo Jun KANG ; Kyung-Do HAN ; Jae Hoon CHO ; Ji Ho CHOI
Journal of Rhinology 2025;32(1):48-54
Background and Objectives:
Obstructive sleep apnea (OSA) has been associated with an increased risk of cancer in various organs. OSA is also linked to chronic inflammation in the biliary tract and pancreas, a well-established risk factor for carcinogenesis in these organs. However, its relationship with biliary tract and pancreatic cancers remains unclear and has been rarely investigated. Therefore, we aimed to evaluate whether OSA serves as an independent risk factor for these malignancies by analyzing a nationwide healthcare claims database in South Korea.
Methods:
A retrospective cohort study was conducted using the Korean National Health Insurance Service (KNHIS) database. Adults aged ≥20 years who were newly diagnosed with OSA (ICD-10: G47.30) between 2007 and 2014 were identified and propensity score-matched (1:5) with controls based on age, sex, and comorbidities. Individuals with pre-existing cancer diagnoses were excluded. The primary endpoints were the incidence of overall cancer, biliary tract cancer (C23–C24), and pancreatic cancer (C25). Cox proportional hazards regression models were used to calculate hazard ratios (HRs), adjusting for demographic and clinical factors.
Results:
A total of 1,191,444 individuals were included, comprising 198,574 patients diagnosed with OSA and 992,870 matched controls. OSA was associated with an increased overall cancer incidence (HR, 1.132; 95% confidence interval [CI], 1.097–1.169); however, it was not significantly associated with pancreatic cancer (HR, 0.941; 95% CI, 0.823–1.072) or biliary tract cancer (HR, 0.931; 95% CI, 0.751–1.142). Subgroup analyses stratified by sex and age revealed no statistically significant associations across these groups.
Conclusion
Our findings do not support OSA as an independent risk factor for biliary tract or pancreatic cancers.
4.Long-Term Incidence of Gastrointestinal Bleeding Following Ischemic Stroke
Jun Yup KIM ; Beom Joon KIM ; Jihoon KANG ; Do Yeon KIM ; Moon-Ku HAN ; Seong-Eun KIM ; Heeyoung LEE ; Jong-Moo PARK ; Kyusik KANG ; Soo Joo LEE ; Jae Guk KIM ; Jae-Kwan CHA ; Dae-Hyun KIM ; Tai Hwan PARK ; Kyungbok LEE ; Hong-Kyun PARK ; Yong-Jin CHO ; Keun-Sik HONG ; Kang-Ho CHOI ; Joon-Tae KIM ; Dong-Eog KIM ; Jay Chol CHOI ; Mi-Sun OH ; Kyung-Ho YU ; Byung-Chul LEE ; Kwang-Yeol PARK ; Ji Sung LEE ; Sujung JANG ; Jae Eun CHAE ; Juneyoung LEE ; Min-Surk KYE ; Philip B. GORELICK ; Hee-Joon BAE ;
Journal of Stroke 2025;27(1):102-112
Background:
and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes.
Methods:
We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data.
Results:
Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4.
Conclusion
Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.
5.Low-Density Lipoprotein Cholesterol Level, the Lower the Better? Analysis of Korean Patients in the Treat Stroke to Target Trial
Hanim KWON ; Jae-Chan RYU ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2025;27(2):228-236
Background:
and Purpose The Treat Stroke to Target (TST) was a randomized clinical trial involving French and Korean patients demonstrating that a lower low-density lipoprotein cholesterol (LDL-C, <70 mg/dL) target group (LT) experienced fewer cerebro-cardiovascular events than a higher target (90–110 mg/dL) group (HT). However, whether these results can be applied to Asian patients with different ischemic stroke subtypes remains unclear.
Methods:
Patients from 14 South Korean centers were analyzed separately. Patients with ischemic stroke or transient ischemic attack with evidence of atherosclerosis were randomized into LT and HT groups. The primary endpoint was a composite of ischemic stroke, myocardial infarction, coronary or cerebral revascularization, and cardiovascular death.
Results:
Among 712 enrolled patients, the mean LDL-C level was 71.0 mg/dL in 357 LT patients and 86.1 mg/dL in 355 HT patients. The primary endpoint occurred in 24 (6.7%) of LT and in 31 (8.7%) of HT group patients (adjusted hazard ratio [HR]=0.78; 95% confidence interval [CI]=0.45–1.33, P=0.353). Cardiovascular events alone occurred significantly less frequently in the LT than in the HT group (HR 0.26, 95% CI 0.09–0.80, P=0.019), whereas there were no significant differences in ischemic stroke events (HR 1.12, 95% CI 0.60–2.10, P=0.712). The benefit of LT was less apparent in patients with small vessel disease and intracranial atherosclerosis than in those with extracranial atherosclerosis.
Conclusion
In contrast to the French TST, the outcomes in Korean patients were neutral. Although LT was more effective in preventing cardiovascular diseases, it was not so in stroke prevention, probably attributed to the differences in stroke subtypes. Further studies are needed to elucidate the efficacy of statins and appropriate LDL-C targets in Asian patients with stroke.
6.Diagnosis of Pneumocystis jirovecii Pneumonia in Non-HIV Immunocompromised Patient in Korea: A Review and Algorithm Proposed by Expert Consensus Group
Raeseok LEE ; Kyungmin HUH ; Chang Kyung KANG ; Yong Chan KIM ; Jung Ho KIM ; Hyungjin KIM ; Jeong Su PARK ; Ji Young PARK ; Heungsup SUNG ; Jongtak JUNG ; Chung-Jong KIM ; Kyoung-Ho SONG
Infection and Chemotherapy 2025;57(1):45-62
Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection commonly observed in immunocompromised patients, necessitating prompt diagnosis and treatment. This review evaluates the diagnostic performance of various tests used for PJP diagnosis through a comprehensive literature review. Additionally, we propose a diagnostic algorithm tailored to non-human immunodeficiency virus immunocompromised patients, considering the specific characteristics of current medical resources in Korea.
7.Gaps and Similarities in Research Use LOINC Codes Utilized in Korean University Hospitals: Towards Semantic Interoperability for Patient Care
Kuenyoul PARK ; Min-Sun KIM ; YeJin OH ; John Hoon RIM ; Shinae YU ; Hyejin RYU ; Eun-Jung CHO ; Kyunghoon LEE ; Ha Nui KIM ; Inha CHUN ; AeKyung KWON ; Sollip KIM ; Jae-Woo CHUNG ; Hyojin CHAE ; Ji Seon OH ; Hyung-Doo PARK ; Mira KANG ; Yeo-Min YUN ; Jong-Baeck LIM ; Young Kyung LEE ; Sail CHUN
Journal of Korean Medical Science 2025;40(1):e4-
Background:
The accuracy of Logical Observation Identifiers Names and Codes (LOINC) mappings is reportedly low, and the LOINC codes used for research purposes in Korea have not been validated for accuracy or usability. Our study aimed to evaluate the discrepancies and similarities in interoperability using existing LOINC mappings in actual patient care settings.
Methods:
We collected data on local test codes and their corresponding LOINC mappings from seven university hospitals. Our analysis focused on laboratory tests that are frequently requested, excluding clinical microbiology and molecular tests. Codes from nationwide proficiency tests served as intermediary benchmarks for comparison. A research team, comprising clinical pathologists and terminology experts, utilized the LOINC manual to reach a consensus on determining the most suitable LOINC codes.
Results:
A total of 235 LOINC codes were designated as optimal codes for 162 frequent tests.Among these, 51 test items, including 34 urine tests, required multiple optimal LOINC codes, primarily due to unnoted properties such as whether the test was quantitative or qualitative, or differences in measurement units. We analyzed 962 LOINC codes linked to 162 tests across seven institutions, discovering that 792 (82.3%) of these codes were consistent. Inconsistencies were most common in the analyte component (38 inconsistencies, 33.3%), followed by the method (33 inconsistencies, 28.9%), and properties (13 inconsistencies, 11.4%).
Conclusion
This study reveals a significant inconsistency rate of over 15% in LOINC mappings utilized for research purposes in university hospitals, underlining the necessity for expert verification to enhance interoperability in real patient care.
8.Gaps and Similarities in Research Use LOINC Codes Utilized in Korean University Hospitals: Towards Semantic Interoperability for Patient Care
Kuenyoul PARK ; Min-Sun KIM ; YeJin OH ; John Hoon RIM ; Shinae YU ; Hyejin RYU ; Eun-Jung CHO ; Kyunghoon LEE ; Ha Nui KIM ; Inha CHUN ; AeKyung KWON ; Sollip KIM ; Jae-Woo CHUNG ; Hyojin CHAE ; Ji Seon OH ; Hyung-Doo PARK ; Mira KANG ; Yeo-Min YUN ; Jong-Baeck LIM ; Young Kyung LEE ; Sail CHUN
Journal of Korean Medical Science 2025;40(1):e4-
Background:
The accuracy of Logical Observation Identifiers Names and Codes (LOINC) mappings is reportedly low, and the LOINC codes used for research purposes in Korea have not been validated for accuracy or usability. Our study aimed to evaluate the discrepancies and similarities in interoperability using existing LOINC mappings in actual patient care settings.
Methods:
We collected data on local test codes and their corresponding LOINC mappings from seven university hospitals. Our analysis focused on laboratory tests that are frequently requested, excluding clinical microbiology and molecular tests. Codes from nationwide proficiency tests served as intermediary benchmarks for comparison. A research team, comprising clinical pathologists and terminology experts, utilized the LOINC manual to reach a consensus on determining the most suitable LOINC codes.
Results:
A total of 235 LOINC codes were designated as optimal codes for 162 frequent tests.Among these, 51 test items, including 34 urine tests, required multiple optimal LOINC codes, primarily due to unnoted properties such as whether the test was quantitative or qualitative, or differences in measurement units. We analyzed 962 LOINC codes linked to 162 tests across seven institutions, discovering that 792 (82.3%) of these codes were consistent. Inconsistencies were most common in the analyte component (38 inconsistencies, 33.3%), followed by the method (33 inconsistencies, 28.9%), and properties (13 inconsistencies, 11.4%).
Conclusion
This study reveals a significant inconsistency rate of over 15% in LOINC mappings utilized for research purposes in university hospitals, underlining the necessity for expert verification to enhance interoperability in real patient care.
9.Low-Density Lipoprotein Cholesterol Level, the Lower the Better? Analysis of Korean Patients in the Treat Stroke to Target Trial
Hanim KWON ; Jae-Chan RYU ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2025;27(2):228-236
Background:
and Purpose The Treat Stroke to Target (TST) was a randomized clinical trial involving French and Korean patients demonstrating that a lower low-density lipoprotein cholesterol (LDL-C, <70 mg/dL) target group (LT) experienced fewer cerebro-cardiovascular events than a higher target (90–110 mg/dL) group (HT). However, whether these results can be applied to Asian patients with different ischemic stroke subtypes remains unclear.
Methods:
Patients from 14 South Korean centers were analyzed separately. Patients with ischemic stroke or transient ischemic attack with evidence of atherosclerosis were randomized into LT and HT groups. The primary endpoint was a composite of ischemic stroke, myocardial infarction, coronary or cerebral revascularization, and cardiovascular death.
Results:
Among 712 enrolled patients, the mean LDL-C level was 71.0 mg/dL in 357 LT patients and 86.1 mg/dL in 355 HT patients. The primary endpoint occurred in 24 (6.7%) of LT and in 31 (8.7%) of HT group patients (adjusted hazard ratio [HR]=0.78; 95% confidence interval [CI]=0.45–1.33, P=0.353). Cardiovascular events alone occurred significantly less frequently in the LT than in the HT group (HR 0.26, 95% CI 0.09–0.80, P=0.019), whereas there were no significant differences in ischemic stroke events (HR 1.12, 95% CI 0.60–2.10, P=0.712). The benefit of LT was less apparent in patients with small vessel disease and intracranial atherosclerosis than in those with extracranial atherosclerosis.
Conclusion
In contrast to the French TST, the outcomes in Korean patients were neutral. Although LT was more effective in preventing cardiovascular diseases, it was not so in stroke prevention, probably attributed to the differences in stroke subtypes. Further studies are needed to elucidate the efficacy of statins and appropriate LDL-C targets in Asian patients with stroke.
10.A Comparison between Keratograph 5M® and IDRA® in Dry Eye Patients
Seo Woo PARK ; Ha-Rim SO ; Ji Won BAEK ; Ho Sik HWANG ; Kyung-Sun NA ; Ho RA ; Nam Yeo KANG ; Hyun Seung KIM ; Eun Chul KIM
Journal of the Korean Ophthalmological Society 2025;66(4):175-180
Purpose:
To evaluate the compatibility and usability of test results obtained from the IDRA and Keratograph 5M in clinical settings by comparing their performance in patients with dry eye disease.
Methods:
From December 27 to 30, 2022, a study was conducted on 30 patients diagnosed with dry eye utilizing both the Keratograph 5M and IDRA devices. The parameters compared and analyzed included lipid layer thickness, tear meniscus height, tear film break-up time, and meibography. A paired t-test was used for statistical comparison. The lipid layer thickness in the Keratograph 5M was graded on a scale from 0 to 4 based on thickness.
Results:
No significant differences were found between the two devices in tear film break-up time, tear meniscus height, and meibography (p = 0.148, 0.072, 0.124, respectively). However, the tear lipid layer thickness measured by IDRA showed a proportional relationship with the grade assigned by the Keratograph 5M (Kendall R = 0.217, p = 0.037; Spearman R = 0.260, p = 0.045).
Conclusions
The IDRA device offers the advantage of performing multiple dry eye tests; simultaneously, thereby saving time compared to the Keratograph 5M. Both devices can be used compatibly with IDRA particularly advantageous for providing a numerical value for tear lipid layer thickness which enhances the convenience of dry eye diagnosis and treatment.

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