1.Guidelines for the Storage, Isolation, and Characterization of Extracellular Vesicle Research
Shinwon CHAE ; Woocheol JUNG ; Yoon-Jin LEE ; Dongsic CHOI
Journal of Digestive Cancer Research 2025;13(1):9-29
Extracellular vesicles (EVs) are lipid bilayer-enclosed particles that contain diverse molecular components, such as proteins, nucleic acids, and lipids. EVs reflect the state of their cell of origin in intercellular communication. Such characteristics of EVs demonstrate their potential as biomarkers and therapeutic agents in basic and translational research. Research on EV biology and applications has progressed significantly. However, challenges remain in translating their potential into clinical applications because of issues in nomenclature, the separation of EVs from nonvesicular extracellular particles, and methods for characterization and functional analysis. The International Society for Extracellular Vesicles addresses the current standards and challenges in this rapidly evolving field through periodical updates of its Minimal Information for Studies of Extracellular Vesicles (MISEV), which was published in 2014 and revised in 2018. The latest revision, MISEV2023, provides an updated overview of the current methodologies, detailing their strengths and limitations in EV production, separation, and characterization from various sources, including cell cultures, body fluids, and solid tissues. In this review, we summarize the fundamental principles of EV research by referencing the guidelines on EVs published by the Ministry of Food and Drug Safety of the Republic of Korea. Furthermore, we elaborate on the key aspects of MISEV2023, providing information for domestic EV researchers in selecting or developing optimal research methodologies according to their specific objectives and applications.
2.Guidelines for the Storage, Isolation, and Characterization of Extracellular Vesicle Research
Shinwon CHAE ; Woocheol JUNG ; Yoon-Jin LEE ; Dongsic CHOI
Journal of Digestive Cancer Research 2025;13(1):9-29
Extracellular vesicles (EVs) are lipid bilayer-enclosed particles that contain diverse molecular components, such as proteins, nucleic acids, and lipids. EVs reflect the state of their cell of origin in intercellular communication. Such characteristics of EVs demonstrate their potential as biomarkers and therapeutic agents in basic and translational research. Research on EV biology and applications has progressed significantly. However, challenges remain in translating their potential into clinical applications because of issues in nomenclature, the separation of EVs from nonvesicular extracellular particles, and methods for characterization and functional analysis. The International Society for Extracellular Vesicles addresses the current standards and challenges in this rapidly evolving field through periodical updates of its Minimal Information for Studies of Extracellular Vesicles (MISEV), which was published in 2014 and revised in 2018. The latest revision, MISEV2023, provides an updated overview of the current methodologies, detailing their strengths and limitations in EV production, separation, and characterization from various sources, including cell cultures, body fluids, and solid tissues. In this review, we summarize the fundamental principles of EV research by referencing the guidelines on EVs published by the Ministry of Food and Drug Safety of the Republic of Korea. Furthermore, we elaborate on the key aspects of MISEV2023, providing information for domestic EV researchers in selecting or developing optimal research methodologies according to their specific objectives and applications.
3.Guidelines for the Storage, Isolation, and Characterization of Extracellular Vesicle Research
Shinwon CHAE ; Woocheol JUNG ; Yoon-Jin LEE ; Dongsic CHOI
Journal of Digestive Cancer Research 2025;13(1):9-29
Extracellular vesicles (EVs) are lipid bilayer-enclosed particles that contain diverse molecular components, such as proteins, nucleic acids, and lipids. EVs reflect the state of their cell of origin in intercellular communication. Such characteristics of EVs demonstrate their potential as biomarkers and therapeutic agents in basic and translational research. Research on EV biology and applications has progressed significantly. However, challenges remain in translating their potential into clinical applications because of issues in nomenclature, the separation of EVs from nonvesicular extracellular particles, and methods for characterization and functional analysis. The International Society for Extracellular Vesicles addresses the current standards and challenges in this rapidly evolving field through periodical updates of its Minimal Information for Studies of Extracellular Vesicles (MISEV), which was published in 2014 and revised in 2018. The latest revision, MISEV2023, provides an updated overview of the current methodologies, detailing their strengths and limitations in EV production, separation, and characterization from various sources, including cell cultures, body fluids, and solid tissues. In this review, we summarize the fundamental principles of EV research by referencing the guidelines on EVs published by the Ministry of Food and Drug Safety of the Republic of Korea. Furthermore, we elaborate on the key aspects of MISEV2023, providing information for domestic EV researchers in selecting or developing optimal research methodologies according to their specific objectives and applications.
4.Generative Adversarial Network-Based Image Conversion Among Different Computed Tomography Protocols and Vendors: Effects on Accuracy and Variability in Quantifying Regional Disease Patterns of Interstitial Lung Disease
Hye Jeon HWANG ; Hyunjong KIM ; Joon Beom SEO ; Jong Chul YE ; Gyutaek OH ; Sang Min LEE ; Ryoungwoo JANG ; Jihye YUN ; Namkug KIM ; Hee Jun PARK ; Ho Yun LEE ; Soon Ho YOON ; Kyung Eun SHIN ; Jae Wook LEE ; Woocheol KWON ; Joo Sung SUN ; Seulgi YOU ; Myung Hee CHUNG ; Bo Mi GIL ; Jae-Kwang LIM ; Youkyung LEE ; Su Jin HONG ; Yo Won CHOI
Korean Journal of Radiology 2023;24(8):807-820
Objective:
To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software.
Materials and Methods:
This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1–7 according to acquisition conditions. CT images in groups 2–7 were converted into the target CT sty le (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system.
Results:
Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2–7 improved after CT conversion (original vs. converted: 0.63vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists’ scores were significantly higher (P < 0.001) and less variable on converted CT.
Conclusion
CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.
5.Erratum: Correction of Affiliations in the Article “Establishment of a Nationwide Korean Imaging Cohort of Coronavirus Disease 2019”
Soon Ho YOON ; Soo-Youn HAM ; Bo Da NAM ; Kum Ju CHAE ; Dabee LEE ; Jin Young YOO ; So Hyeon BAK ; Jin Young KIM ; Jin Hwan KIM ; Ki Beom KIM ; Jung Im JUNG ; Jae-Kwang LIM ; Jong Eun LEE ; Myung Jin CHUNG ; Young Kyung LEE ; Young Seon KIM ; Ji Eun JO ; Sang Min LEE ; Woocheol KWON ; Chang Min PARK ; Yun-Hyeon KIM ; Yeon Joo JEONG
Journal of Korean Medical Science 2023;38(34):e298-
6.Imaging Assessment of Visceral Pleural Surface Invasion by Lung Cancer: Comparison of CT and Contrast-Enhanced Radial T1-Weighted Gradient Echo 3-Tesla MRI
Yu ZHANG ; Woocheol KWON ; Ho Yun LEE ; Sung Min KO ; Sang-Ha KIM ; Won-Yeon LEE ; Suk Joong YONG ; Soon-Hee JUNG ; Chun Sung BYUN ; JunHyeok LEE ; Honglei YANG ; Junhee HAN ; Jeanne B. ACKMAN
Korean Journal of Radiology 2021;22(5):829-839
Objective:
To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura.
Materials and Methods:
Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed.Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT).
Results:
At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI.
Conclusion
The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.
7.Imaging Assessment of Visceral Pleural Surface Invasion by Lung Cancer: Comparison of CT and Contrast-Enhanced Radial T1-Weighted Gradient Echo 3-Tesla MRI
Yu ZHANG ; Woocheol KWON ; Ho Yun LEE ; Sung Min KO ; Sang-Ha KIM ; Won-Yeon LEE ; Suk Joong YONG ; Soon-Hee JUNG ; Chun Sung BYUN ; JunHyeok LEE ; Honglei YANG ; Junhee HAN ; Jeanne B. ACKMAN
Korean Journal of Radiology 2021;22(5):829-839
Objective:
To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura.
Materials and Methods:
Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed.Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT).
Results:
At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI.
Conclusion
The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.
8.Establishment of a Nationwide Korean Imaging Cohort of Coronavirus Disease 2019
Soon Ho YOON ; Soo-Youn HAM ; Bo Da NAM ; Kum Ju CHAE ; Dabee LEE ; Jin Young YOO ; So Hyeon BAK ; Jin Young KIM ; Jin Hwan KIM ; Ki Beom KIM ; Jung Im JUNG ; Jae-Kwang LIM ; Jong Eun LEE ; Myung Jin CHUNG ; Young Kyung LEE ; Young Seon KIM ; Ji Eun JO ; Sang Min LEE ; Woocheol KWON ; Chang Min PARK ; Yun-Hyeon KIM ; Yeon Joo JEONG
Journal of Korean Medical Science 2020;35(46):e413-
Background:
The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19.
Methods:
The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital.
Results:
The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11–97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit.Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs.
Conclusion
The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19.
9.Morphologic Evaluation of Primary Non-Small Cell Lung Cancer by 3 Tesla MRI with Free-Breathing Ultrashort Echo Time and Radial T1-Weighted Gradient Echo Sequences: A Comparison with CT Analysis
Hyunji LEE ; EunHee CHOI ; Myoung Kyu LEE ; Yu ZHANG ; Woocheol KWON
Journal of the Korean Radiological Society 2019;80(3):466-476
PURPOSE:
To evaluate morphologic features of primary non-small cell lung cancer using 3 Tesla MRI with free-breathing compared with CT.
MATERIALS AND METHODS:
Thirty-six patients were enrolled. A 64-channel multidetector CT and 3 Tesla MRI with ultrashort echo time pointwise encoding time reduction with radial acquisition (PETRA) and radial volumetric interpolated breath-hold examination (VIBE) were compared in size, shape, margin, internal characteristics, and tumor interface of primary tumor.
RESULTS:
There were no significant differences in tumor size between CT and either PETRA or radial VIBE (p = 0.054 and p = 0.764, respectively). Kappa (κ) statistics of shape, margin, and internal characteristics were respectively κ = 0.86, 0.65, 0.77 on PETRA and κ = 0.93, 0.84, 0.83 on radial VIBE compared with CT. PETRA and radial VIBE revealed clearer interface compared with CT (p = 0.000 and p < 0.000, respectively). Radial VIBE showed higher frequency of clear interface (94.4%) than PETRA (88.9%). MRI did not show significantly clear interface which was located in lung base (p = 0.363 on PETRA and p = 0.175 on radial VIBE) compared with CT.
CONCLUSION
MRI with PETRA and radial VIBE sequences can be a feasible method to evaluate morphologic features of primary non-small cell lung cancer compared with CT.
10.Effect of acidic solutions on the microhardness of dentin and set OrthoMTA and their cytotoxicity on murine macrophage.
Soram OH ; Hiran PERINPANAYAGAM ; Yoon LEE ; Jae Won KUM ; Yeon Jee YOO ; Sang Min LIM ; Seok Woo CHANG ; Won Jun SHON ; Woocheol LEE ; Seung Ho BAEK ; Kee Yeon KUM
Restorative Dentistry & Endodontics 2016;41(1):12-21
OBJECTIVES: To evaluate the effects of three acids on the microhardness of set mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage. MATERIALS AND METHODS: OrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage. RESULTS: Three test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%). CONCLUSIONS: Tested acidic solutions reduced microhardness of root dentin. Five minute's application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA.
Cell Survival
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Citric Acid
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Dentin*
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Edetic Acid
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Humans
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Macrophages*
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Pemetrexed

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