1.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
2.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
3.Comparison between Suture-Button Technique with Syndesmotic Repair and Screw Fixation Technique for Complete Ankle Syndesmotic Injury: Biomechanical Cadaveric Study
Hong Seop LEE ; Sung Hwan KIM ; Ki Won YOUNG ; Woo Jong KIM ; Dong-Il CHEON ; Sung Hun WON ; Sang Heon LEE ; Seung Jin CHOI ; Young Koo LEE
Clinics in Orthopedic Surgery 2025;17(2):324-330
Background:
The tibiofibular syndesmosis is essential for preserving the stability of the ankle. Acute syndesmotic injuries with evident or latent instability usually warrant surgical interventions. This cadaveric study examines and compares biomechanical characteristics between the following treatments for syndesmosis injuries: suture-button fixation plus syndesmotic repair and screw fixation.
Methods:
The lower extremities of 10 cadavers disarticulated at the knee joints were used, yielding 20 feet. Ten feet underwent surgery using the suture-button fixation with syndesmotic repair, while the remaining 10 feet underwent surgery using screw fixation. Before surgical treatment of syndesmosis injuries, each cadaveric lower limb underwent preliminary physiological cyclic loading, which was followed by a series of postfixation cyclic loading tests after the surgical procedure.
Results:
Our principal finding is that suture-button fixation with syndesmotic repair provided torsional strength comparable to that of screw fixation. The mean failure torque did not differ between the 2 groups, but the rotational stiffness was significantly lower in the suture-button fixation/augmentation group.
Conclusions
Suture-button fixation/augmentation facilitates flexible (physiological) syndesmosis movement and may be a useful alternative treatment for ankle syndesmosis injury.
4.Expert consensus on oral corticosteroid use and tapering in severe asthma management
Joo-Hee KIM ; Noeul KANG ; Sung-Yoon KANG ; Da Woon SIM ; So-Young PARK ; Jong-Sook PARK ; Hyun LEE ; Hyun Jung JIN ; Woo-Jung SONG ; So Ri KIM ; Sang-Heon KIM
Allergy, Asthma & Respiratory Disease 2025;13(1):12-21
Systemic corticosteroids play an essential role in the management of asthma. During acute exacerbation, the short-term use of systemic corticosteroids is recommended. For patients with uncontrolled asthma and severe asthma, long-term and low-dose oral corticosteroids (OCS) have frequently been advocated. However, both short-term and long-term use of systemic corticosteroids carry the risk of adverse events (AEs), including various morbidities and even mortality. Despite recent progress in adult severe asthma management and the availability of new treatment options, the current domestic guidelines for asthma do not provide specific recommendations for oral corticosteroid tapering in patients with severe asthma. Therefore, the task force team of the severe asthma working group in the Korean Academy of Allergy, Asthma, and Clinical Immunology has proposed a tapering protocol for systemic corticosteroid use in severe asthma. This includes practical recommendations for monitoring OCS-related AE, particularly for adrenal insufficiency and osteoporosis, which suggests corticosteroid-sparing strategies that include alternative therapies, modifying treatable traits, timely specialist assessment, and shared decision-making with patients. However, further real-world research and collaboration with doctors from primary and academic institutes, patients, and policymakers are necessary to establish an OCS stewardship approach. This should include realistic OCS-tapering strategies for patients with severe asthma using regular OCS, education, and campaigns for patients, the public, and healthcare providers about the burden of severe asthma, as well as improving timely access to specialized severe asthma services for optimal management.
5.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
6.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
7.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
8.Comparison between Suture-Button Technique with Syndesmotic Repair and Screw Fixation Technique for Complete Ankle Syndesmotic Injury: Biomechanical Cadaveric Study
Hong Seop LEE ; Sung Hwan KIM ; Ki Won YOUNG ; Woo Jong KIM ; Dong-Il CHEON ; Sung Hun WON ; Sang Heon LEE ; Seung Jin CHOI ; Young Koo LEE
Clinics in Orthopedic Surgery 2025;17(2):324-330
Background:
The tibiofibular syndesmosis is essential for preserving the stability of the ankle. Acute syndesmotic injuries with evident or latent instability usually warrant surgical interventions. This cadaveric study examines and compares biomechanical characteristics between the following treatments for syndesmosis injuries: suture-button fixation plus syndesmotic repair and screw fixation.
Methods:
The lower extremities of 10 cadavers disarticulated at the knee joints were used, yielding 20 feet. Ten feet underwent surgery using the suture-button fixation with syndesmotic repair, while the remaining 10 feet underwent surgery using screw fixation. Before surgical treatment of syndesmosis injuries, each cadaveric lower limb underwent preliminary physiological cyclic loading, which was followed by a series of postfixation cyclic loading tests after the surgical procedure.
Results:
Our principal finding is that suture-button fixation with syndesmotic repair provided torsional strength comparable to that of screw fixation. The mean failure torque did not differ between the 2 groups, but the rotational stiffness was significantly lower in the suture-button fixation/augmentation group.
Conclusions
Suture-button fixation/augmentation facilitates flexible (physiological) syndesmosis movement and may be a useful alternative treatment for ankle syndesmosis injury.
9.Expert consensus on oral corticosteroid use and tapering in severe asthma management
Joo-Hee KIM ; Noeul KANG ; Sung-Yoon KANG ; Da Woon SIM ; So-Young PARK ; Jong-Sook PARK ; Hyun LEE ; Hyun Jung JIN ; Woo-Jung SONG ; So Ri KIM ; Sang-Heon KIM
Allergy, Asthma & Respiratory Disease 2025;13(1):12-21
Systemic corticosteroids play an essential role in the management of asthma. During acute exacerbation, the short-term use of systemic corticosteroids is recommended. For patients with uncontrolled asthma and severe asthma, long-term and low-dose oral corticosteroids (OCS) have frequently been advocated. However, both short-term and long-term use of systemic corticosteroids carry the risk of adverse events (AEs), including various morbidities and even mortality. Despite recent progress in adult severe asthma management and the availability of new treatment options, the current domestic guidelines for asthma do not provide specific recommendations for oral corticosteroid tapering in patients with severe asthma. Therefore, the task force team of the severe asthma working group in the Korean Academy of Allergy, Asthma, and Clinical Immunology has proposed a tapering protocol for systemic corticosteroid use in severe asthma. This includes practical recommendations for monitoring OCS-related AE, particularly for adrenal insufficiency and osteoporosis, which suggests corticosteroid-sparing strategies that include alternative therapies, modifying treatable traits, timely specialist assessment, and shared decision-making with patients. However, further real-world research and collaboration with doctors from primary and academic institutes, patients, and policymakers are necessary to establish an OCS stewardship approach. This should include realistic OCS-tapering strategies for patients with severe asthma using regular OCS, education, and campaigns for patients, the public, and healthcare providers about the burden of severe asthma, as well as improving timely access to specialized severe asthma services for optimal management.
10.Expert consensus on oral corticosteroid use and tapering in severe asthma management
Joo-Hee KIM ; Noeul KANG ; Sung-Yoon KANG ; Da Woon SIM ; So-Young PARK ; Jong-Sook PARK ; Hyun LEE ; Hyun Jung JIN ; Woo-Jung SONG ; So Ri KIM ; Sang-Heon KIM
Allergy, Asthma & Respiratory Disease 2025;13(1):12-21
Systemic corticosteroids play an essential role in the management of asthma. During acute exacerbation, the short-term use of systemic corticosteroids is recommended. For patients with uncontrolled asthma and severe asthma, long-term and low-dose oral corticosteroids (OCS) have frequently been advocated. However, both short-term and long-term use of systemic corticosteroids carry the risk of adverse events (AEs), including various morbidities and even mortality. Despite recent progress in adult severe asthma management and the availability of new treatment options, the current domestic guidelines for asthma do not provide specific recommendations for oral corticosteroid tapering in patients with severe asthma. Therefore, the task force team of the severe asthma working group in the Korean Academy of Allergy, Asthma, and Clinical Immunology has proposed a tapering protocol for systemic corticosteroid use in severe asthma. This includes practical recommendations for monitoring OCS-related AE, particularly for adrenal insufficiency and osteoporosis, which suggests corticosteroid-sparing strategies that include alternative therapies, modifying treatable traits, timely specialist assessment, and shared decision-making with patients. However, further real-world research and collaboration with doctors from primary and academic institutes, patients, and policymakers are necessary to establish an OCS stewardship approach. This should include realistic OCS-tapering strategies for patients with severe asthma using regular OCS, education, and campaigns for patients, the public, and healthcare providers about the burden of severe asthma, as well as improving timely access to specialized severe asthma services for optimal management.

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