1.Deep Learning-Accelerated Non-Contrast Abbreviated Liver MRI for Detecting Malignant Focal Hepatic Lesions: Dual-Center Validation
So Hyun PARK ; Moon Hyung CHOI ; Bohyun KIM ; Hyun-Soo LEE ; Sungjin YOON ; Young Joon LEE ; Dominik NICKEL ; Thomas BENKERT
Korean Journal of Radiology 2025;26(4):333-345
Objective:
To compare a deep learning (DL)-accelerated non-enhanced abbreviated MRI (AMRI DL) protocol with standard AMRI (AMRI STD) of the liver in terms of image quality and malignant focal lesion detection.
Materials and Methods:
This retrospective study included 155 consecutive patients (110 male; mean age 62.4 ± 11 years) from two sites who underwent standard liver MRI and additional AMRIDL sequences, specifically DL-accelerated single-shot fast-spin echo (SSFSE DL) and DL-accelerated diffusion-weighted imaging (DWIDL). Additional MRI phantom experiments assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values. Three reviewers evaluated AMRIDL and AMRI STD protocols for image quality using a five-point Likert scale and identified malignant hepatic lesions. Image quality scores and per-lesion sensitivities were compared between AMRIDL and AMRI STD using the Wilcoxon signed-rank test and logistic regression with generalized estimating equations, respectively.
Results:
Phantom experiments demonstrated comparable SNR and higher CNR for SSFSE DL compared to SSFSE STD, with similar ADC values for DWIDL and DWI STD. Among the 155 patients, 130 (83.9%) had chronic liver disease or a history of intra- or extrahepatic malignancy. Of 104 malignant focal lesions in 64 patients, 58 (55.8%) were hepatocellular carcinomas (HCCs), 38 (36.5%) were metastases, four (3.8%) were cholangiocarcinomas, and four (3.8%) were lymphomas. The pooled per-lesion sensitivity across three readers was 97.6% for AMRIDL, comparable to 97.6% for AMRI STD. Compared with AMRI STD, AMRIDL demonstrated superior image quality regarding structural sharpness, artifacts, and noise (all P < 0.001) and reduced the average scan time by approximately 50% (2 min 29 sec vs. 4 min 11 sec). In patients with chronic liver disease, AMRIDL achieved a 96.6% per-lesion sensitivity for HCC detection, similar to 96.5% for AMRI STD (P > 0.05).
Conclusion
The AMRIDL protocol offers comparable sensitivity for detecting malignant focal lesions, including HCC while significantly enhancing image quality and reducing scan time by approximately 50% compared to AMRI STD.
2.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
3.Histological Assessment and Interobserver Agreement in Major Pathologic Response for Non–Small Cell Lung Cancer with Neoadjuvant Therapy
Sungjin KIM ; Jeonghyo LEE ; Jin-Haeng CHUNG
Cancer Research and Treatment 2025;57(2):401-411
Purpose:
Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction.
Materials and Methods:
This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images.
Results:
Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012).
Conclusion
While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.
4.Deep Learning-Accelerated Non-Contrast Abbreviated Liver MRI for Detecting Malignant Focal Hepatic Lesions: Dual-Center Validation
So Hyun PARK ; Moon Hyung CHOI ; Bohyun KIM ; Hyun-Soo LEE ; Sungjin YOON ; Young Joon LEE ; Dominik NICKEL ; Thomas BENKERT
Korean Journal of Radiology 2025;26(4):333-345
Objective:
To compare a deep learning (DL)-accelerated non-enhanced abbreviated MRI (AMRI DL) protocol with standard AMRI (AMRI STD) of the liver in terms of image quality and malignant focal lesion detection.
Materials and Methods:
This retrospective study included 155 consecutive patients (110 male; mean age 62.4 ± 11 years) from two sites who underwent standard liver MRI and additional AMRIDL sequences, specifically DL-accelerated single-shot fast-spin echo (SSFSE DL) and DL-accelerated diffusion-weighted imaging (DWIDL). Additional MRI phantom experiments assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values. Three reviewers evaluated AMRIDL and AMRI STD protocols for image quality using a five-point Likert scale and identified malignant hepatic lesions. Image quality scores and per-lesion sensitivities were compared between AMRIDL and AMRI STD using the Wilcoxon signed-rank test and logistic regression with generalized estimating equations, respectively.
Results:
Phantom experiments demonstrated comparable SNR and higher CNR for SSFSE DL compared to SSFSE STD, with similar ADC values for DWIDL and DWI STD. Among the 155 patients, 130 (83.9%) had chronic liver disease or a history of intra- or extrahepatic malignancy. Of 104 malignant focal lesions in 64 patients, 58 (55.8%) were hepatocellular carcinomas (HCCs), 38 (36.5%) were metastases, four (3.8%) were cholangiocarcinomas, and four (3.8%) were lymphomas. The pooled per-lesion sensitivity across three readers was 97.6% for AMRIDL, comparable to 97.6% for AMRI STD. Compared with AMRI STD, AMRIDL demonstrated superior image quality regarding structural sharpness, artifacts, and noise (all P < 0.001) and reduced the average scan time by approximately 50% (2 min 29 sec vs. 4 min 11 sec). In patients with chronic liver disease, AMRIDL achieved a 96.6% per-lesion sensitivity for HCC detection, similar to 96.5% for AMRI STD (P > 0.05).
Conclusion
The AMRIDL protocol offers comparable sensitivity for detecting malignant focal lesions, including HCC while significantly enhancing image quality and reducing scan time by approximately 50% compared to AMRI STD.
5.Deep Learning-Accelerated Non-Contrast Abbreviated Liver MRI for Detecting Malignant Focal Hepatic Lesions: Dual-Center Validation
So Hyun PARK ; Moon Hyung CHOI ; Bohyun KIM ; Hyun-Soo LEE ; Sungjin YOON ; Young Joon LEE ; Dominik NICKEL ; Thomas BENKERT
Korean Journal of Radiology 2025;26(4):333-345
Objective:
To compare a deep learning (DL)-accelerated non-enhanced abbreviated MRI (AMRI DL) protocol with standard AMRI (AMRI STD) of the liver in terms of image quality and malignant focal lesion detection.
Materials and Methods:
This retrospective study included 155 consecutive patients (110 male; mean age 62.4 ± 11 years) from two sites who underwent standard liver MRI and additional AMRIDL sequences, specifically DL-accelerated single-shot fast-spin echo (SSFSE DL) and DL-accelerated diffusion-weighted imaging (DWIDL). Additional MRI phantom experiments assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values. Three reviewers evaluated AMRIDL and AMRI STD protocols for image quality using a five-point Likert scale and identified malignant hepatic lesions. Image quality scores and per-lesion sensitivities were compared between AMRIDL and AMRI STD using the Wilcoxon signed-rank test and logistic regression with generalized estimating equations, respectively.
Results:
Phantom experiments demonstrated comparable SNR and higher CNR for SSFSE DL compared to SSFSE STD, with similar ADC values for DWIDL and DWI STD. Among the 155 patients, 130 (83.9%) had chronic liver disease or a history of intra- or extrahepatic malignancy. Of 104 malignant focal lesions in 64 patients, 58 (55.8%) were hepatocellular carcinomas (HCCs), 38 (36.5%) were metastases, four (3.8%) were cholangiocarcinomas, and four (3.8%) were lymphomas. The pooled per-lesion sensitivity across three readers was 97.6% for AMRIDL, comparable to 97.6% for AMRI STD. Compared with AMRI STD, AMRIDL demonstrated superior image quality regarding structural sharpness, artifacts, and noise (all P < 0.001) and reduced the average scan time by approximately 50% (2 min 29 sec vs. 4 min 11 sec). In patients with chronic liver disease, AMRIDL achieved a 96.6% per-lesion sensitivity for HCC detection, similar to 96.5% for AMRI STD (P > 0.05).
Conclusion
The AMRIDL protocol offers comparable sensitivity for detecting malignant focal lesions, including HCC while significantly enhancing image quality and reducing scan time by approximately 50% compared to AMRI STD.
6.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
7.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
8.Histological Assessment and Interobserver Agreement in Major Pathologic Response for Non–Small Cell Lung Cancer with Neoadjuvant Therapy
Sungjin KIM ; Jeonghyo LEE ; Jin-Haeng CHUNG
Cancer Research and Treatment 2025;57(2):401-411
Purpose:
Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction.
Materials and Methods:
This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images.
Results:
Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012).
Conclusion
While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.
9.Deep Learning-Accelerated Non-Contrast Abbreviated Liver MRI for Detecting Malignant Focal Hepatic Lesions: Dual-Center Validation
So Hyun PARK ; Moon Hyung CHOI ; Bohyun KIM ; Hyun-Soo LEE ; Sungjin YOON ; Young Joon LEE ; Dominik NICKEL ; Thomas BENKERT
Korean Journal of Radiology 2025;26(4):333-345
Objective:
To compare a deep learning (DL)-accelerated non-enhanced abbreviated MRI (AMRI DL) protocol with standard AMRI (AMRI STD) of the liver in terms of image quality and malignant focal lesion detection.
Materials and Methods:
This retrospective study included 155 consecutive patients (110 male; mean age 62.4 ± 11 years) from two sites who underwent standard liver MRI and additional AMRIDL sequences, specifically DL-accelerated single-shot fast-spin echo (SSFSE DL) and DL-accelerated diffusion-weighted imaging (DWIDL). Additional MRI phantom experiments assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values. Three reviewers evaluated AMRIDL and AMRI STD protocols for image quality using a five-point Likert scale and identified malignant hepatic lesions. Image quality scores and per-lesion sensitivities were compared between AMRIDL and AMRI STD using the Wilcoxon signed-rank test and logistic regression with generalized estimating equations, respectively.
Results:
Phantom experiments demonstrated comparable SNR and higher CNR for SSFSE DL compared to SSFSE STD, with similar ADC values for DWIDL and DWI STD. Among the 155 patients, 130 (83.9%) had chronic liver disease or a history of intra- or extrahepatic malignancy. Of 104 malignant focal lesions in 64 patients, 58 (55.8%) were hepatocellular carcinomas (HCCs), 38 (36.5%) were metastases, four (3.8%) were cholangiocarcinomas, and four (3.8%) were lymphomas. The pooled per-lesion sensitivity across three readers was 97.6% for AMRIDL, comparable to 97.6% for AMRI STD. Compared with AMRI STD, AMRIDL demonstrated superior image quality regarding structural sharpness, artifacts, and noise (all P < 0.001) and reduced the average scan time by approximately 50% (2 min 29 sec vs. 4 min 11 sec). In patients with chronic liver disease, AMRIDL achieved a 96.6% per-lesion sensitivity for HCC detection, similar to 96.5% for AMRI STD (P > 0.05).
Conclusion
The AMRIDL protocol offers comparable sensitivity for detecting malignant focal lesions, including HCC while significantly enhancing image quality and reducing scan time by approximately 50% compared to AMRI STD.
10.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.

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