1.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
2.Coronary Artery Dimension-Adjusted Subtended Myocardial Mass Obtained With Coronary CT Angiography as a Potential Biomarker of Myocardial Ischemia in Patients With Hypertrophic Cardiomyopathy
Jung Han WOO ; Hyewon CHOI ; Min Jae CHA
Korean Journal of Radiology 2025;26(4):324-332
Objective:
To compare coronary artery dimension-adjusted subtended myocardial mass between patients with hypertrophic cardiomyopathy (HCM) and a normal population without detectable atherosclerosis, and between HCM patients with and without chest pain.
Materials and Methods:
Twenty-five patients with HCM but no detectable atherosclerosis on coronary computed tomography angiography (CCTA) were included in the study. This group comprised 14 patients with chest pain and 11 patients without chest pain. They were matched with 25 healthy participants based on sex, age, coronary dominance pattern, and body surface area. The minimal lumen area (MLA) and subtended myocardial volume (V sub) were assessed in the left main (LM), proximal left anterior descending (pLAD), proximal left circumflex (pLCx), and proximal right coronary (pRCA) arteries. Additionally, an index of the subtended myocardial mass adjusted for the MLA, calculated as V sub/MLA 2 , was determined.
Results:
MLA was significantly larger in patients with HCM compared to the control group in LM (20.93 ± 6.31 mm 2 vs.15.24 ± 3.90 mm 2 , P< 0.001), pLAD (14.28 ± 3.55 mm 2 vs. 11.36 ± 2.07 mm 2, P = 0.001), pLCx (10.94 ± 3.60 mm 2 vs. 9.15 ± 2.93 mm 2 , P = 0.045), and pRCA (13.41 ± 4.85 mm 2 vs. 11.22 ± 3.20 mm 2 , P = 0.018). Despite an increase in coronary luminal area, patients with HCM exhibited significantly higher V sub/MLA 2 compared to the control group in both the pLAD (403.56 ± 200.35 mm -1 vs. 241.70 ± 85.87 mm -1 , P < 0.001) and the pRCA (186.06 ± 95.07 mm -1 vs. 125.07 ± 70.18 mm -1 , P= 0.007). V sub/MLA 2 was significantly elevated in patients with chest pain compared to those without in the pLAD (473.75 ± 227.38 mm -1 vs. 314.24 ± 110.74 mm -1 , P = 0.018) and the pLCx (417.04 ± 182.65 mm -1 vs. 275.29 ± 112.97 mm -1 , P = 0.044).
Conclusion
CCTA-derived V sub/MLA 2 may more accurately reflect the balance between myocardial blood supply and demand, offering insights into the occurrence of demand angina in patients with HCM without obstructive coronary artery disease.
4.Prevalence of asymptomatic malaria in high- and low-transmission areas of Tanzania: The role of asymptomatic carriers in malaria persistence and the need for targeted surveillance and control efforts
Ernest MAZIGO ; Hojong JUN ; Wang-Jong LEE ; Johnsy Mary LOUIS ; Fadhila FITRIANA ; Jadidan Hada SYAHADA ; Fauzi MUH ; Feng LU ; Md Atique AHMED ; Seok Ho CHA ; Wanjoo CHUN ; Won Sun PARK ; Se Jin LEE ; Sunghun NA ; Joon-Hee HAN ; Nyalali KIJA ; Smart GEODFREY ; Eun-Teak HAN ; Jim TODD ; Alphaxard MANJURANO ; Winifrida KIDIMA ; Jin-Hee HAN
Parasites, Hosts and Diseases 2025;63(1):57-65
As many countries implement different programs aimed at eliminating malaria, attention should be given to asymptomatic carriers that may interrupt the progress. This was a community-based cross-sectional study conducted in Tanzania from December 2022 to July 2023 within 4 villages from each of the 3 regions, Geita and Kigoma, which are high malaria transmission, and Arusha, which is low transmission. Malaria was diagnosed in asymptomatic individuals aged 1 year and older using the malaria rapid diagnostic test and light microscope. A total of 2,365 of 3,489 (67.9%) participants were enrolled from high-transmission villages. The overall prevalence was 25.5% and 15.8% by malaria rapid diagnostic test and light microscope, respectively. Using the respective tools, the prevalence was significantly higher at 35.6% (confidence interval (CI)=23.6–49.9) and 23.1% (CI=16.2–35.1) in the high-transmission regions (Geita and Kigoma) compared with 2.9% (CI=1.1–3.5) and 1.1% (CI=0.7–1.8) in the low-transmission region (Arusha). Children younger than 15 years and males accounted for the greatest proportion of infections. In the study area, the prevalence of asymptomatic cases was higher than that of reported symptomatic cases in health facilities. We hypothesize that these parasite reservoirs may contribute to the persistence of malaria in the country. Therefore, to achieve comprehensive malaria control in the country, the surveillance and screening of asymptomatic malaria cases are vital.
5.Coronary Artery Dimension-Adjusted Subtended Myocardial Mass Obtained With Coronary CT Angiography as a Potential Biomarker of Myocardial Ischemia in Patients With Hypertrophic Cardiomyopathy
Jung Han WOO ; Hyewon CHOI ; Min Jae CHA
Korean Journal of Radiology 2025;26(4):324-332
Objective:
To compare coronary artery dimension-adjusted subtended myocardial mass between patients with hypertrophic cardiomyopathy (HCM) and a normal population without detectable atherosclerosis, and between HCM patients with and without chest pain.
Materials and Methods:
Twenty-five patients with HCM but no detectable atherosclerosis on coronary computed tomography angiography (CCTA) were included in the study. This group comprised 14 patients with chest pain and 11 patients without chest pain. They were matched with 25 healthy participants based on sex, age, coronary dominance pattern, and body surface area. The minimal lumen area (MLA) and subtended myocardial volume (V sub) were assessed in the left main (LM), proximal left anterior descending (pLAD), proximal left circumflex (pLCx), and proximal right coronary (pRCA) arteries. Additionally, an index of the subtended myocardial mass adjusted for the MLA, calculated as V sub/MLA 2 , was determined.
Results:
MLA was significantly larger in patients with HCM compared to the control group in LM (20.93 ± 6.31 mm 2 vs.15.24 ± 3.90 mm 2 , P< 0.001), pLAD (14.28 ± 3.55 mm 2 vs. 11.36 ± 2.07 mm 2, P = 0.001), pLCx (10.94 ± 3.60 mm 2 vs. 9.15 ± 2.93 mm 2 , P = 0.045), and pRCA (13.41 ± 4.85 mm 2 vs. 11.22 ± 3.20 mm 2 , P = 0.018). Despite an increase in coronary luminal area, patients with HCM exhibited significantly higher V sub/MLA 2 compared to the control group in both the pLAD (403.56 ± 200.35 mm -1 vs. 241.70 ± 85.87 mm -1 , P < 0.001) and the pRCA (186.06 ± 95.07 mm -1 vs. 125.07 ± 70.18 mm -1 , P= 0.007). V sub/MLA 2 was significantly elevated in patients with chest pain compared to those without in the pLAD (473.75 ± 227.38 mm -1 vs. 314.24 ± 110.74 mm -1 , P = 0.018) and the pLCx (417.04 ± 182.65 mm -1 vs. 275.29 ± 112.97 mm -1 , P = 0.044).
Conclusion
CCTA-derived V sub/MLA 2 may more accurately reflect the balance between myocardial blood supply and demand, offering insights into the occurrence of demand angina in patients with HCM without obstructive coronary artery disease.
7.Prevalence of asymptomatic malaria in high- and low-transmission areas of Tanzania: The role of asymptomatic carriers in malaria persistence and the need for targeted surveillance and control efforts
Ernest MAZIGO ; Hojong JUN ; Wang-Jong LEE ; Johnsy Mary LOUIS ; Fadhila FITRIANA ; Jadidan Hada SYAHADA ; Fauzi MUH ; Feng LU ; Md Atique AHMED ; Seok Ho CHA ; Wanjoo CHUN ; Won Sun PARK ; Se Jin LEE ; Sunghun NA ; Joon-Hee HAN ; Nyalali KIJA ; Smart GEODFREY ; Eun-Teak HAN ; Jim TODD ; Alphaxard MANJURANO ; Winifrida KIDIMA ; Jin-Hee HAN
Parasites, Hosts and Diseases 2025;63(1):57-65
As many countries implement different programs aimed at eliminating malaria, attention should be given to asymptomatic carriers that may interrupt the progress. This was a community-based cross-sectional study conducted in Tanzania from December 2022 to July 2023 within 4 villages from each of the 3 regions, Geita and Kigoma, which are high malaria transmission, and Arusha, which is low transmission. Malaria was diagnosed in asymptomatic individuals aged 1 year and older using the malaria rapid diagnostic test and light microscope. A total of 2,365 of 3,489 (67.9%) participants were enrolled from high-transmission villages. The overall prevalence was 25.5% and 15.8% by malaria rapid diagnostic test and light microscope, respectively. Using the respective tools, the prevalence was significantly higher at 35.6% (confidence interval (CI)=23.6–49.9) and 23.1% (CI=16.2–35.1) in the high-transmission regions (Geita and Kigoma) compared with 2.9% (CI=1.1–3.5) and 1.1% (CI=0.7–1.8) in the low-transmission region (Arusha). Children younger than 15 years and males accounted for the greatest proportion of infections. In the study area, the prevalence of asymptomatic cases was higher than that of reported symptomatic cases in health facilities. We hypothesize that these parasite reservoirs may contribute to the persistence of malaria in the country. Therefore, to achieve comprehensive malaria control in the country, the surveillance and screening of asymptomatic malaria cases are vital.
8.Association of Age, Sex and Education With Access to the Intravenous Thrombolysis for Acute Ischemic Stroke
Yoona KO ; Beom Joon KIM ; Youngran KIM ; Jong-Moo PARK ; Kyusik KANG ; Jae Guk KIM ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Kyung-Ho YU ; Dong-Eog KIM ; Joon-Tae KIM ; Jay Chol CHOI ; Jee Hyun KWON ; Wook-Joo KIM ; Kyu Sun YUM ; Sung-Il SOHN ; Hyungjong PARK ; Sang-Hwa LEE ; Kwang-Yeol PARK ; Chi Kyung KIM ; Sung Hyuk HEO ; Moon-Ku HAN ; Anjail Z. SHARRIEF ; Sunil A. SHETH ; Hee-Joon BAE ;
Journal of Korean Medical Science 2025;40(13):e49-
Background:
Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients.
Methods:
We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates.
Results:
Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively).
Conclusion
Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.
9.Additional Screw Added to the Femoral Neck System Could Enhance the Stability of Pauwel Type III Femoral Neck Fractures:a Finite Element Analysis
Yonghan CHA ; Sunghoon PARK ; Chang-Ho JUNG ; Jin-Woo KIM ; Jun-Il YOO ; Jung-Taek KIM ; Yongho JEON ; Kyeong Jin HAN
Clinics in Orthopedic Surgery 2025;17(2):204-215
Background:
This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS).
Methods:
Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied.
Results:
With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions.
Conclusions
The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.
10.Early Single-Stage Curettage and Autogenous Bone Grafting for Enchondroma in the Hand with Minimally Displaced Pathologic Fracture
Cheungsoo HA ; Chi-Hoon OH ; Segi KIM ; Ju-Sung LEE ; Soo-Hong HAN
Clinics in Orthopedic Surgery 2025;17(1):174-180
Background:
Enchondroma is a common benign bone tumor in the hand, often leading to delayed diagnosis due to its asymptomatic nature. The surgical treatment strategy for enchondroma, particularly in pathologic fractures, remains unclear. This study aimed to evaluate the outcomes of treatment for non- or minimally displaced pathologic fractures in enchondroma using autogenous bone grafts alone, without metal fixation.
Methods:
A retrospective analysis was conducted on 34 patients who underwent surgery for enchondroma and pathologic fractures. Clinical and radiographic outcomes were assessed, including pain scores, range of motion (ROM), Disabilities of the Arm, Shoulder, and Hand (DASH) score, grip strength, fracture union time, and complications.
Results:
All patients reported pain at the fracture site preoperatively. The preoperative pain visual analog scale (VAS) score was 4.5.Postoperatively, the pain VAS score improved significantly to 2.3. The postoperative average total ROM was 253.8°. The average DASH score was 5.1, and grip strength was 97.8% compared to the unaffected side. Bony union was achieved in all cases with an average union time of 10.9 weeks. No complications were observed except for 1 suspected recurrence.
Conclusions
Early single-stage surgical treatment with curettage and autogenous bone grafts without fixation yielded satisfactory results for non- or minimally displaced pathologic fractures in enchondroma. This non-fixative technique offers a viable option with reduced treatment duration and implant-related complications.

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