1.Deep Learning-Based Computer-Aided Diagnosis in Coronary Artery Calcium-Scoring CT for Pulmonary Nodule Detection: A Preliminary Study
Seung Yun LEE ; Ji Weon LEE ; Jung Im JUNG ; Kyunghwa HAN ; Suyon CHANG
Yonsei Medical Journal 2025;66(4):240-248
Purpose:
To evaluate the feasibility and utility of deep learning-based computer-aided diagnosis (DL-CAD) for the detection of pulmonary nodules on coronary artery calcium (CAC)-scoring computed tomography (CT).
Materials and Methods:
This retrospective study included 273 patients (aged 63.9±13.2 years; 129 men) who underwent CACscoring CT. A DL-CAD system based on thin-section images was used for pulmonary nodule detection, and two independent junior readers reviewed the standard CAC-scoring CT scans with and without referencing DL-CAD results. A reference standard was established through the consensus of two experienced radiologists. Sensitivity, positive predictive value, and F1-score were assessed on a per-nodule and per-patient basis. The patients’ medical records were monitored until November 2023.
Results:
A total of 269 nodules were identified in 129 patients. With DL-CAD assistance, the readers’ sensitivity significantly improved (65% vs. 80% for reader 1; 82% vs. 86% for reader 2; all p<0.001), without a notable increase in the number of false-positives per case (0.11 vs. 0.13, p=0.078 for reader 1; 0.11 vs. 0.11, p>0.999 for reader 2). Per-patient analysis also enhanced sensitivity with DL-CAD assistance (73% vs. 84%, p<0.001 for reader 1; 89% vs. 91%, p=0.250 for reader 2). During follow-up, lung cancer was diagnosed in four patients (1.5%). Among them, two had lesions detected on CAC-scoring CT, both of which were successfully identified by DL-CAD.
Conclusion
DL-CAD based on thin-section images can assist less experienced readers in detecting pulmonary nodules on CACscoring CT scans, improving detection sensitivity without significantly increasing false-positives.
2.Prospective Evaluation of Various Ultrasound Parameters for Assessing Renal Allograft Rejection Subtypes: Elasticity and Dispersion as Diagnostic Tools
Yeji KWON ; Jongjin YOON ; Dae Chul JUNG ; Young Taik OH ; Kyunghwa HAN ; Minsun JUNG ; Byung Chul KANG
Yonsei Medical Journal 2025;66(4):249-258
Purpose:
Renal allograft rejection, either acute or chronic, is prevalent among many recipients. This study aimed to identify multiple Doppler ultrasound parameters for predicting renal allograft rejection.
Materials and Methods:
Between November 2021 and April 2022, 61 renal allograft recipients were studied prospectively after excluding two patients with dual transplants and seven with hydronephrosis. The analysis excluded 11 cases (10 due to missing Doppler data or pathology reports and one due to a high interquartile range/median dispersion value), resulting in a final analysis of 50 patients. Clinical characteristics, color Doppler imaging, superb microvascular imaging, and shear-wave imaging parameters were assessed by three experienced genitourinary radiologists. The Banff classification of the biopsy tissue served as the reference standard. Univariable and multivariable logistic regression, contingency matrices, and multiple machine-learning models were employed to estimate the associations.
Results:
Fifty kidney transplant recipients (mean age, 53.26±8.86 years; 29 men) were evaluated. Elasticity (≤14.8 kPa) demonstrated significant associations for predicting the combination of (borderline) T cell-mediated rejection (TCMR) categories (Banff categories 3 and 4) (p=0.006) and yielded equal or higher area under the receiver operating characteristics curve (AUC) values compared to various classifiers. Dispersion (>15.0 m/s/kHz) was the only significant factor for predicting the combination of nonTCMR categories (Banff categories 2, 5, and 6) (p=0.026) and showed equal or higher AUC values than multiple machine learning classifiers.
Conclusion
Elasticity (≤14.8 kPa) showed a significant association with the combination of (borderline) TCMR categories, whereas dispersion (>15.0 m/s/kHz) was significantly associated with the combination of non-TCMR categories in renal allografts.
3.Conventional versus Instillation Negative-Pressure Wound Therapy for Severe Soft Tissue Injury in Open Pelvic Fractures: A Retrospective Review
Donghwan CHOI ; Won Tae CHO ; Hyung Keun SONG ; Junsik KWON ; Byung Hee KANG ; Hohyung JUNG ; Min Ji KIM ; Kyoungwon JUNG
Yonsei Medical Journal 2025;66(2):94-102
Purpose:
We investigated the clinical features, current negative-pressure wound therapy (NPWT) management strategies, and outcomes of pelvic-perineal soft tissue infection after open pelvic fractures.
Materials and Methods:
We analyzed the data of patients admitted to our trauma center with pelvic-perineal soft tissue after open pelvic fractures over a 7-year period. We investigated the injury severity score (ISS), medical costs, number of NPWTs, time required to reach definite wound coverage, complications, fracture classifications, transfusion requirements, interventions, length of stay (LOS) in hospital and intensive care unit (ICU), and prognosis.
Results:
Twenty patients with open pelvic fractures were treated with NPWT, and one patient who underwent NPWT died of pelvic sepsis during ICU treatment. The median LOS in hospital and medical costs were 98 [56–164] days and 106400 [65600–171100] USD, respectively. Patients treated with instillation NPWT (iNPWT, n=10) had a shorter NPWT duration (24 [13–39] vs. 46 [42–91] days, p=0.023), time to definite wound coverage (30 [21–43] vs. 49 [42–93] days, p=0.026), and hospital LOS (56 [43–72] vs. 158 [101–192] days, p=0.001), as well as lower medical costs (67800 [42500–102500] vs. 144200 [110400–236000] USD, p=0.009) compared to those treated with conventional NPWT.
Conclusion
NPWT is a feasible method for treating pelvic soft tissue infections in patients with open pelvic fractures. iNPWT can reduce the duration of NPWT, hospital LOS, and medical costs.
4.Vitamin D Attenuates Non-Alcoholic Fatty Liver Disease in High-Fat Diet-Induced Obesity Murine Model
Sook In CHUNG ; Lin LIANG ; Heejae HAN ; Kyung Hee PARK ; Jae-Hyun LEE ; Jung-Won PARK
Yonsei Medical Journal 2025;66(2):75-86
Purpose:
Obesity and metabolic syndrome are acknowledged as key factors contributing to the development of non-alcoholic fatty liver disease (NAFLD). Vitamin D (VitD) is a multifaceted secosteroid hormone known for its anti-fibrotic and anti-inflammatory properties, with its deficiency often linked to obesity. Our study aimed to investigate whether VitD supplementation could mitigate the liver pathology associated with NAFLD.
Materials and Methods:
The NAFLD model was developed by subjecting male C57BL/6 mice to a high-fat diet (HFD) for 14 weeks.These mice were supplemented with VitD through intraperitoneal injection at a dosage of 7 μg/kg, administered three times per week for 7 weeks.
Results:
HFD resulted in VitD deficiency, insulin resistance, and increased liver weight. It elevated serum levels of liver aminotransferases and triglyceride, ultimately leading to steatohepatitis with fibrosis. This model exhibited increased levels of transforming growth factor (TGF)-β1, pro-inflammatory cytokines, HNF4α transcription factors, reactive oxygen species (ROS), renin-angiotensin system activity, and epithelial-mesenchymal transitions (EMT) within the liver. Supplementation with VitD resulted in the recovery of liver weight, improvement in histologic features associated with steatohepatitis, and reduction in alanine aminotransferases and triglyceride levels induced by the HFD. Additionally, it mitigated the HFD-induced over-expressions of TGF-β1 and fibrosis-related genes, along with pro-inflammatory cytokines and ROS. Notably, no adverse effect was found due to VitD supplementation in this model.
Conclusion
VitD ameliorates steatohepatitis within obesity-induced NAFLD through its multifaceted pathways. VitD supplementation emerges as a potentially safe, cost-effective, and direct treatment approach for NAFLD patients dealing with obesity or metabolic dysfunction.
5.Artificial Intelligence-Based Early Prediction of Acute Respiratory Failure in the Emergency Department Using Biosignal and Clinical Data
Changho HAN ; Yun Jung JUNG ; Ji Eun PARK ; Wou Young CHUNG ; Dukyong YOON
Yonsei Medical Journal 2025;66(2):121-130
Purpose:
Early identification of patients at risk for acute respiratory failure (ARF) could help clinicians devise preventive strategies. Analyzing biosignals with artificial intelligence (AI) can uncover hidden information and variability within time series. We aimed to develop and validate AI models to predict ARF within 72 h after emergency department admission, primarily using highresolution biosignals collected within 4 h of arrival.
Materials and Methods:
Our AI model, built on convolutional recurrent neural networks, combines biosignal feature extraction and sequence modeling. The model was developed and internally validated with data from 5284 admissions [1085 (20.5%) positive for ARF], and externally validated using data from 144 admissions [7 (4.9%) positive for ARF] from another institution. We defined ARF as the application of advanced respiratory support devices.
Results:
Our AI model performed well in predicting ARF, achieving area under the receiver operating characteristic curve (AUROC) of 0.840 and 0.743 in internal and external validations, respectively. It outperformed the Modified Early Warning Score (MEWS) and XGBoost models built only with clinical variables. High predictive ability for mortality was observed, with AUROC up to 0.809. A 10% increase in AI prediction scores was associated with 1.44-fold and 1.42-fold increases in ARF risk and mortality risk, respectively, even after adjusting for MEWS and demographic variables.
Conclusion
Our AI model demonstrates high predictive accuracy and significant associations with clinical outcomes. Our AI model has the potential to promptly aid in triage decisions. Our study shows that using AI to analyze biosignals advances disease detection and prediction.
6.Experiences of Surgical Approach for Aortoduodenal Fistula Repairs in Abdominal Aortic Aneurysm Patients
Ji Eun JUNG ; Seyeol OH ; In Gyu KWON
Yonsei Medical Journal 2025;66(1):37-42
Purpose:
This study aimed to analyze the characteristics and outcomes of patients with an aortoduodenal fistula (ADF) who underwent surgical treatment at a single institution.
Materials and Methods:
The data of patients diagnosed with ADF at the Yonsei University Gangnam Severance Hospital, South Korea, between 2019 and 2022 were included. Primary repair and segmental resection of the duodenum with duodeno-jejunostomy were the two main methods used to repair ADF.
Results:
Among the 15 patients analyzed, most were male, and the median age was 68 years. Based on the cause of ADF, five patients had primary ADF, whereas the remaining had secondary ADF. The average duration from fistula diagnosis to surgery was 23.5 days (2.8 days in primary ADF cases and 33.8 days in secondary ADF cases). Primary repair of the ADF was performed for eight patients, and segmental resection of the duodenum with duodeno-jejunostomy was performed for the remaining patients.Omentopexy was performed for all patients. The median duration of hospital stay was 32.7 days. Three patients died after surgery;however, all 11 patients operated on by the single experienced surgeon survived until the last follow-up.
Conclusion
To the best of our knowledge, this study is the first original article on ADF. Our findings suggest that ADF repairs performed by experienced surgeons would provide favorable results. Although primary repair is the first treatment choice, duodenojejunostomy is recommended when it is not feasible. By choosing the appropriate procedure depending on the case, favorable outcomes without any fatalities can be achieved.
7.Validation of Devices for the Five Times Sit To Stand Test:Comparing Plantar Pressure and Head Motion Analysis with Manual Measurement
Sanghyun JEE ; Chan Woong JANG ; Kyoungmin PARK ; Sanghoon SHIN ; Min-Chul PAEK ; Jung Hyun PARK
Yonsei Medical Journal 2025;66(1):51-57
Purpose:
This study aims to evaluate a new method for the five times sit to stand test (FTSST), crucial for addressing frailty in an aging population. It utilizes a smart insole for plantar pressure analysis and a marker-less motion capture device for head height analysis.
Materials and Methods:
Thirty-five participants aged 50 years or older underwent FTSST assessment using three methods: manual measurement with a stopwatch (FTSST-M), plantar pressure analysis with smart insoles (FTSST-P), and head height analysis with a marker-less motion capture device (FTSST-H). Simultaneous measurements using three methods were done. Correlation between results of these methods were analyzed using intraclass correlation coefficient (ICC) and κ coefficient. Comprehensive clinical examinations were conducted with ethical approval.
Results:
Participants’ mean scores for FTSST-M, FTSST-P, and FTSST-H were 2.43±1.20, 2.43±1.29, and 2.37±1.31, respectively. Correlations of the times and corresponding scores between FTSST-P and FTSST-M, as well as FTSST-H and FTSST-M, exceeded 0.9 (ICC and κ coefficients, p<0.001). Using an FTSST score of 3 or less to indicate vulnerability, the κ value for vulnerability classification between two measurements was 0.886 (p<0.001).
Conclusion
This study showed strong correlation between FTSST results using smart insoles and marker-less motion capture, compared to conventional methods. These findings highlight the potential of these technologies for precise FTSST measurements, offering convenience and cost-effectiveness. Simultaneous use of these devices enables diverse analyses, enhancing our understanding of frailty.
8.Concurrent Association of Multifocality, Bilaterality, and Recurrence in Pediatric Papillary Thyroid Cancer Patients
Jae Won CHO ; Cheong-Sil RAH ; Won Woong KIM ; Yu-mi LEE ; Seong Chul KIM ; Jung Hwan BAEK ; Dong Eun SONG ; Won Gu KIM ; Ki-Wook CHUNG ; Suck Joon HONG ; Tae-Yon SUNG
Yonsei Medical Journal 2025;66(1):43-50
Purpose:
Pediatric papillary thyroid cancer (PTC) is recommended to perform aggressive surgery to reduce the risk of recurrence.This study was designed to evaluate the concurrent association between multifocality, bilaterality, and the risk of recurrence in pediatric PTC.
Materials and Methods:
This retrospective cohort study included pediatric patients (age <19 years) who underwent total thyroidectomy for PTC between 1996 and 2014 in a single tertiary center. Clinicopathological parameters were analyzed to evaluate the prevalence of multifocality, bilaterality, recurrence, and their association.
Results:
We analyzed 58 pediatric patients with PTC. There was no factor related to the presence of multifocality or bilaterality in multivariate analysis. Also, in univariate analysis, multifocality and bilaterality were not independent risk factors of each other’s presentation (p=0.061 and p=0.061, respectively). Recurrence was observed in 19 (32.8%) patients. In multivariate analysis of recurrence, clear cell subtype, multifocality, and gross extrathyroidal extension (ETE) were independent risk factors (p=0.027, p=0.035, and p=0.038, respectively). Most recurrences (68.4%) happened during the first 4 years of follow-up after the initial thyroidectomy.
Conclusion
Multifocality and bilaterality were not independent risk factors of each other’s presentation; however, multifocality was the risk factor for recurrence in pediatric PTC. For pediatric PTC, close monitoring for recurrence within the initial 4 years is recommended, particularly in patients with clear cell subtype, multifocality, and gross ETE.
9.Patient with Behçet Syndrome with Subaortic Pseudoaneurysm Who Underwent the Bentall Operation Showed Improvement after Medical Treatment
Hanbyul LEE ; Chang Sin KIM ; Jo Won JUNG ; Han Ki PARK ; Jong Gyun AHN
Yonsei Medical Journal 2025;66(6):390-394
Aortic regurgitation (AR) in children is usually caused by congenital valve anomalies, and Behçet syndrome (BS) can be suspected in cases of isolated AR. Patients with BS undergoing aortic valve surgery due to aortic valve invasion have a high risk of complications, such as leakage around the valve and dehiscence. Cardiovascular involvement occurs in 7%–46% of adult patients with BS and is the main cause of mortality; however, its prevalence is unclear and rare in children. A 12-year-old boy was diagnosed with severe AR associated with BS. A progressive subaortic pseudoaneurysm was observed after aortic valve replacement. The periaortic intracardiac pouch was at risk of rupture; therefore, the patient underwent a Bentall operation. After the Bentall procedure, a newly developed subaortic pseudoaneurysm was detected below the prosthetic valve. However, the risk of rupture reduced as the subaortic pseudoaneurysm regressed with anti-inflammatory drugs alone without reoperation. Repeated surgery is inevitable in patients with BS undergoing aortic valve surgery due to the progressive chronic inflammatory reactions that present with a pseudoaneurysm. Here, we report an 8-year follow-up of a pediatric case of BS with subaortic pseudoaneurysm, highlighting the importance of close follow-up, medical management, and early diagnosis in treating this condition.
10.Non-Inferiority Analysis of Electrocardiography Analysis Application vs. Point-of-Care Ultrasound for Screening Left Ventricular Dysfunction
Jin Hee KIM ; Jae Yun JUNG ; Joonghee KIM ; Youngjin CHO ; Eunkyoung LEE ; Dahyeon SON
Yonsei Medical Journal 2025;66(3):172-178
Purpose:
Point-of-care ultrasound (POCUS) is widely used for heart function evaluation in emergency departments (EDs), but requires specific equipment and skilled operators. This study evaluates the diagnostic accuracy of a mobile application for estimating left ventricular (LV) systolic dysfunction [left ventricular ejection fraction (LVEF) <40%] using electrocardiography (ECG) and tests its non-inferiority to POCUS.
Materials and Methods:
Patients (aged ≥20 years) were included if they had both a POCUS-based EF evaluation and an ECG within 24 hours of their ED visit between January and May 2022, along with formal echocardiography within 2 weeks before or after the visit. A mobile app (ECG Buddy, EB) estimated LVEF (EF from EB) and the risk of LV dysfunction (LV-Dysfunction score) from ECG waveforms, which were compared to NT-proBNP levels and POCUS-evaluated LVEF (EF from POCUS). A non-inferiority margin was set at an area under the curve (AUC) difference of 0.05.
Results:
Of the 181 patients included, 37 (20.4%) exhibited LV dysfunction. The AUCs for screening LV dysfunction using POCUS and NT-proBNP were 0.885 and 0.822, respectively. EF from EB and LV-Dysfunction score outperformed NT-proBNP, with AUCs of 0.893 and 0.884, respectively (p=0.017 and p=0.030, respectively). EF from EB was non-inferior to EF from POCUS, while LV-Dysfunction score narrowly missed the mark. A subgroup analysis of sinus-origin rhythm ECGs supported the non-inferiority of both EF from EB and LV-Dysfunction score to EF from POCUS.
Conclusion
A smartphone application that analyzes ECG image can screen for LV dysfunction with a level of accuracy comparable to that of POCUS.

Result Analysis
Print
Save
E-mail