1.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
2.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
3.Prognostic Evaluation and Survival Prediction for Combined Hepatocellular-Cholangiocarcinoma Following Hepatectomy
Seok-Joo CHUN ; Yu Jung JUNG ; YoungRok CHOI ; Nam-Joon YI ; Kwang-Woong LEE ; Kyung-Suk SUH ; Kyoung Bun LEE ; Hyun-Cheol KANG ; Eui Kyu CHIE ; Kyung Su KIM
Cancer Research and Treatment 2025;57(1):229-239
Purpose:
This study aimed to assess prognostic factors associated with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and to predict 5-year survival based on these factors.
Materials and Methods:
Patients who underwent definitive hepatectomy from 2006 to 2022 at a single institution was retrospectively analyzed. Inclusion criteria involved a pathologically confirmed diagnosis of cHCC-CCA.
Results:
A total of 80 patients with diagnosed cHCC-CCA were included in the analysis. The median progression-free survival was 15.6 months, while distant metastasis-free survival (DMFS), hepatic progression-free survival, and overall survival (OS) were 50.8, 21.5, and 85.1 months, respectively. In 52 cases of recurrence, intrahepatic recurrence was the most common initial recurrence (34/52), with distant metastasis in 17 cases. Factors associated with poor DMFS included tumor necrosis, lymphovascular invasion (LVI), perineural invasion, and histologic compact type. Postoperative carbohydrate antigen 19-9, tumor necrosis, LVI, and close/positive margin were associated with poor OS. LVI emerged as a key factor affecting both DMFS and OS, with a 5-year OS of 93.3% for patients without LVI compared to 35.8% with LVI. Based on these factors, a nomogram predicting 3-year and 5-year DMFS and OS was developed, demonstrating high concordance with actual survival in the cohort (Harrell C-index 0.809 for OS, 0.801 for DMFS, respectively).
Conclusion
The prognosis of cHCC-CCA is notably poor when combined with LVI. Given the significant impact of adverse features, accurate outcome prediction is crucial. Moreover, consideration of adjuvant therapy may be warranted for patients exhibiting poor survival and increased risk of local recurrence or distant metastasis.
4.Exploring methylation signatures for high de novo recurrence risk in hepatocellular carcinoma
Da-Won KIM ; Jin Hyun PARK ; Suk Kyun HONG ; Min-Hyeok JUNG ; Ji-One PYEON ; Jin-Young LEE ; Kyung-Suk SUH ; Nam-Joon YI ; YoungRok CHOI ; Kwang-Woong LEE ; Young-Joon KIM
Clinical and Molecular Hepatology 2025;31(2):563-576
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits high de novo recurrence rates post-resection. Current post-surgery recurrence prediction methods are limited, emphasizing the need for reliable biomarkers to assess recurrence risk. We aimed to develop methylation-based markers for classifying HCC patients and predicting their risk of de novo recurrence post-surgery.
Methods:
In this retrospective cohort study, we analyzed data from HCC patients who underwent surgical resection in Korea, excluding those with recurrence within one year post-surgery. Using the Infinium Methylation EPIC array on 140 samples in the discovery cohort, we classified patients into low- and high-risk groups based on methylation profiles. Distinctive markers were identified through random forest analysis. These markers were validated in the cancer genome atlas (n=217), Validation cohort 1 (n=63) and experimental Validation using a methylation-sensitive high-resolution melting (MS-HRM) assay in Validation cohort 1 and Validation cohort 2 (n=63).
Results:
The low-risk recurrence group (methylation group 1; MG1) showed a methylation average of 0.73 (95% confidence interval [CI] 0.69–0.77) with a 23.5% recurrence rate, while the high-risk group (MG2) had an average of 0.17 (95% CI 0.14–0.20) with a 44.1% recurrence rate (P<0.03). Validation confirmed the applicability of methylation markers across diverse populations, showing high accuracy in predicting the probability of HCC recurrence risk (area under the curve 96.8%). The MS-HRM assay confirmed its effectiveness in predicting de novo recurrence with 95.5% sensitivity, 89.7% specificity, and 92.2% accuracy.
Conclusions
Methylation markers effectively classified HCC patients by de novo recurrence risk, enhancing prediction accuracy and potentially offering personalized management strategies.
5.Feasibility of indocyanine green fluorescence imaging to predict biliary complications in living donor liver transplantation: A pilot study
Jaewon LEE ; YoungRok CHOI ; Nam-Joon YI ; Jae-Yoon KIM ; Su young HONG ; Jeong-Moo LEE ; Suk Kyun HONG ; Kwang-Woong LEE ; Kyung-Suk SUH
Annals of Hepato-Biliary-Pancreatic Surgery 2025;29(1):32-37
Background:
s/Aims: Liver transplantation (LT) is now a critical, life-saving treatment for patients with liver cirrhosis or hepatocellular carcinoma. Despite its significant benefits, biliary complications (BCs) continue to be a major cause of postoperative morbidity.This study evaluates the fluorescence intensity (FI) of the common bile duct (CBD) utilizing near-infrared indocyanine green (ICG) imaging, and examines its association with the incidence of BCs within three months post-LT.
Methods:
This investigation analyzed data from nine living donor LT (LDLT) recipients who were administered 0.05 mg/kg of ICG prior to bile duct anastomosis. Real-time perfusion of the CBD was recorded for three minutes using an ICG camera, and FI was quantified using Image J (National Institutes of Health). Key parameters assessed included F max, F1/2 max, T1/2 max, and the slope (F max/ T max) to evaluate the fluorescence response.
Results:
BCs occurred in two out of nine patients. These two patients exhibited the longest T1/2 max values, which were linked with lower slope values, implicating a potential relationship between extended T1/2 max, reduced slope, and the occurrence of postoperative BCs.
Conclusions
The study indicates that ICG fluorescence imaging may serve as an effective tool for assessing bile duct perfusion in LDLT patients. While the data suggest that an extended T1/2 max and lower slope may correlate with an increased risk of BCs, further validation through larger studies is required to confirm the predictive value of ICG fluorescence imaging in this setting.
6.Clinical and radiologic outcomes of partial trapeziectomy and suture button suspensionplasty for the treatment of thumb carpometacarpal joint arthritis: a study with a minimum 2-year follow-up
Yeongyoon KOH ; Seul Gi PARK ; Jae Jun NAM ; Jong Woong PARK ; In Cheul CHOI
Archives of hand and microsurgery 2025;30(1):22-28
Purpose:
This study investigated the clinical and radiologic outcomes of partial trapeziectomy and suspensionplasty with a suture button for thumb carpometacarpal (CMC) joint osteoarthritis over a 2-year follow-up period.
Methods:
This retrospective study involved 17 patients with thumb CMC joint osteoarthritis (Eaton and Littler stage II or III) treated with partial trapeziectomy and suspensionplasty using a suture button. Clinical outcomes were evaluated using a visual analog scale for pain, the Quick DASH score, pinch and grip strength, and thumb range of motion. The trapezial space ratio (TSR) was used as a radiologic parameter to evaluate radiologic outcomes immediately postoperatively, at 6 months, and at the final follow-up.
Results:
The study included 17 patients (female, 16 and male, 1) with an average age of 63.2 years (range, 56–70 years). Surgery was performed on the dominant hand in nine cases and the nondominant hand in eight. Significant improvements were observed in clinical outcomes. The TSR significantly decreased up to 6 months postoperatively, but there was no significant change from 6 months onward. Complications included button irritation (n=1), a metacarpal fracture (n=1), and flexor carpi radialis tendon rupture (n=1), which were subsequently treated. At the last follow-up, significant improvements in functional outcomes were observed in comparison to the preoperative status.
Conclusion
The procedure demonstrated significantly improved clinical outcomes over a 2-year follow-up. This method is less invasive than other surgical techniques because it preserves part of the trapezium, making it a favorable surgical option in patients with early basal thumb arthritis (below Eaton stage III).
7.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
8.Predicting renal function using fundus photography: role of confounders
Hyun-Woong PARK ; Hae Ri KIM ; Ki Yup NAM ; Bum Jun KIM ; Taeseen KANG
The Korean Journal of Internal Medicine 2025;40(2):310-320
Background/Aims:
The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction.
Methods:
We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter.
Results:
Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802).
Conclusions
Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.
9.Feasibility of indocyanine green fluorescence imaging to predict biliary complications in living donor liver transplantation: A pilot study
Jaewon LEE ; YoungRok CHOI ; Nam-Joon YI ; Jae-Yoon KIM ; Su young HONG ; Jeong-Moo LEE ; Suk Kyun HONG ; Kwang-Woong LEE ; Kyung-Suk SUH
Annals of Hepato-Biliary-Pancreatic Surgery 2025;29(1):32-37
Background:
s/Aims: Liver transplantation (LT) is now a critical, life-saving treatment for patients with liver cirrhosis or hepatocellular carcinoma. Despite its significant benefits, biliary complications (BCs) continue to be a major cause of postoperative morbidity.This study evaluates the fluorescence intensity (FI) of the common bile duct (CBD) utilizing near-infrared indocyanine green (ICG) imaging, and examines its association with the incidence of BCs within three months post-LT.
Methods:
This investigation analyzed data from nine living donor LT (LDLT) recipients who were administered 0.05 mg/kg of ICG prior to bile duct anastomosis. Real-time perfusion of the CBD was recorded for three minutes using an ICG camera, and FI was quantified using Image J (National Institutes of Health). Key parameters assessed included F max, F1/2 max, T1/2 max, and the slope (F max/ T max) to evaluate the fluorescence response.
Results:
BCs occurred in two out of nine patients. These two patients exhibited the longest T1/2 max values, which were linked with lower slope values, implicating a potential relationship between extended T1/2 max, reduced slope, and the occurrence of postoperative BCs.
Conclusions
The study indicates that ICG fluorescence imaging may serve as an effective tool for assessing bile duct perfusion in LDLT patients. While the data suggest that an extended T1/2 max and lower slope may correlate with an increased risk of BCs, further validation through larger studies is required to confirm the predictive value of ICG fluorescence imaging in this setting.
10.Clinical and radiologic outcomes of partial trapeziectomy and suture button suspensionplasty for the treatment of thumb carpometacarpal joint arthritis: a study with a minimum 2-year follow-up
Yeongyoon KOH ; Seul Gi PARK ; Jae Jun NAM ; Jong Woong PARK ; In Cheul CHOI
Archives of hand and microsurgery 2025;30(1):22-28
Purpose:
This study investigated the clinical and radiologic outcomes of partial trapeziectomy and suspensionplasty with a suture button for thumb carpometacarpal (CMC) joint osteoarthritis over a 2-year follow-up period.
Methods:
This retrospective study involved 17 patients with thumb CMC joint osteoarthritis (Eaton and Littler stage II or III) treated with partial trapeziectomy and suspensionplasty using a suture button. Clinical outcomes were evaluated using a visual analog scale for pain, the Quick DASH score, pinch and grip strength, and thumb range of motion. The trapezial space ratio (TSR) was used as a radiologic parameter to evaluate radiologic outcomes immediately postoperatively, at 6 months, and at the final follow-up.
Results:
The study included 17 patients (female, 16 and male, 1) with an average age of 63.2 years (range, 56–70 years). Surgery was performed on the dominant hand in nine cases and the nondominant hand in eight. Significant improvements were observed in clinical outcomes. The TSR significantly decreased up to 6 months postoperatively, but there was no significant change from 6 months onward. Complications included button irritation (n=1), a metacarpal fracture (n=1), and flexor carpi radialis tendon rupture (n=1), which were subsequently treated. At the last follow-up, significant improvements in functional outcomes were observed in comparison to the preoperative status.
Conclusion
The procedure demonstrated significantly improved clinical outcomes over a 2-year follow-up. This method is less invasive than other surgical techniques because it preserves part of the trapezium, making it a favorable surgical option in patients with early basal thumb arthritis (below Eaton stage III).

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