1.Ultrasound Imaging Features Associated With Neoplastic Gallbladder Polyps: A Systematic Review and Meta-Analysis
Sunyoung LEE ; Won CHANG ; Yeun-Yoon KIM ; Jin Young PARK ; Sun Kyung JEON ; Jeong Eun LEE ; Jeongin YOO ; Seungchul HAN ; So Hyun PARK ; Jae Hyun KIM ; Hyo Jung PARK ; Hyun-Soo ZHANG ; Jeong Hee YOON
Korean Journal of Radiology 2026;27(4):332-343
Objective:
Although most gallbladder polyps are benign, some neoplastic polyps may be malignant or may serve as precursors to malignancy. Distinguishing neoplastic and non-neoplastic polyps using imaging examinations remains a major challenge.This meta-analysis aimed to identify the ultrasound (US) features that are significantly associated with neoplastic polyps.
Materials and Methods:
The MEDLINE, EMBASE, Cochrane, and KoreaMed databases were searched for articles published up to August 31, 2025. Bivariate random-effects models were used to calculate the meta-analytic pooled diagnostic odds ratios (DORs), sensitivities, and specificities, along with their 95% confidence intervals (CIs), for each US imaging feature in the diagnosis of neoplastic polyps.
Results:
Thirty studies evaluating 8,953 patients, including 1,216 (13.6%) patients with neoplastic polyps, were included.Among the nine evaluated US imaging features, namely, size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, heterogeneous echogenicity, gallbladder wall thickening (GBWT), absence of hyperechoic spot, and vascularity, eight were significantly associated with neoplastic polyps: size ≥10 mm (DOR: 6.23 [95% CI: 1.86– 20.90]), sessile morphology (DOR: 3.54 [1.93–5.97]), single polyp (DOR: 2.21 [1.76–2.74]), coexisting gallstones (DOR:1.86 [1.29–2.60]), hypoechogenicity (DOR: 3.55 [1.47–7.30]), GBWT (DOR: 9.38 [1.47–32.20]), absence of hyperechoic spots (DOR: 4.23 [2.46–6.83]), and vascularity (DOR: 9.72 [5.81–15.30]). Of these, size ≥10 mm demonstrated the highest pooled sensitivity (0.79 [95% CI: 0.68–0.87]), whereas hypoechogenicity showed the highest pooled specificity (0.93 [95% CI: 0.82–0.98]).
Conclusion
Eight US imaging features (size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, GBWT, absence of hyperechoic spots, and vascularity) were significantly associated with the presence of neoplastic polyps.These features may facilitate the management of gallbladder polyps.
2.Diagnostic Performance and Clinical Implications of the “Probable Hepatocellular Carcinoma” Category in the Korean Liver Cancer Association-National Cancer Center Korea Guidelines v2022
Jeong Hee YOON ; Jin-Young CHOI ; Young Kon KIM ; Chang Hee LEE ; Jeong Woo KIM ; Won CHANG ; Joon-Il CHOI ; Seung-seob KIM ; Hee Sun PARK ; Eun Sun LEE ; Jeong-Sik YU ; Seong Jin PARK ; Myung-Won YOU ; Myoung-jin JANG ; Beom Jin PARK ; Jeong Min LEE
Korean Journal of Radiology 2026;27(4):318-331
Objective:
To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines.
Materials and Methods:
This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022.
Results:
A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018.
Conclusion
The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.
3.Association of T2-Weighted Imaging Features in Invasive Breast Cancer With Clinicopathologic Features and Neoadjuvant Treatment Outcomes
Inyoung YOUN ; Yun Ho ROH ; Min Jung KIM ; Jung Hyun YOON ; Mi-ri KWON ; Vivian Youngjean PARK
Korean Journal of Radiology 2026;27(4):305-317
Objective:
To investigate the associations between T2-weighted imaging (T2WI) features and clinicopathologic characteristics in invasive breast cancer, as well as their relationship with treatment response to neoadjuvant chemotherapy (NAC).
Materials and Methods:
This retrospective study included 179 women with invasive breast cancer who underwent preoperative 3T breast MRI between November 2020 and February 2021. Intratumoral T2 signal intensity (SI) and peritumoral edema were graded on T2WI, and T2 relaxation times were calculated both including and excluding necrotic or cystic areas. T2 relaxation times were compared across T2 SI grades using the Kruskal–Wallis test. Associations between T2 features and clinicopathologic factors were assessed using chi-square tests and logistic regression analyses. In patients who received NAC (n = 68), associations between T2 features and NAC outcomes were also evaluated.
Results:
Higher intratumoral T2 SI and peritumoral edema grades were significantly associated with longer T2 relaxation times (P < 0.001). Intratumoral T2 SI grades were associated with higher clinical T category, axillary lymph node metastasis, and tumor multiplicity (all P < 0.05). Longer intratumoral T2 relaxation times were associated with higher clinical T category, hormone receptor (HR) negativity, and the triple-negative subtype (all P < 0.05), even after excluding necrotic or cystic areas.Higher peritumoral edema grades were associated with advanced clinical T category, HR negativity, and the triple-negative subtype (all P < 0.05). T2 relaxation times of peritumoral edema showed no significant associations, except with higher clinical T category (P = 0.005) and estrogen receptor status (P = 0.030). In the NAC subgroup, higher intratumoral T2 SI grades and longer T2 relaxation times were significantly associated with disease progression during NAC (P < 0.05), but not with non-pathologic complete response. Peritumoral edema showed no significant association with NAC outcomes (P > 0.05).
Conclusion
T2-weighted MRI features were associated with clinicopathologic factors, including clinical T category, HR status, triple-negative subtype, and disease progression during NAC.
4.Long-Term Pulmonary Function and Radiologic Abnormalities Up to 3 Years After COVID-19:A Systematic Review and Meta-Analysis
Jiyoung SONG ; Jong Hyuk LEE ; Hyungin PARK ; Myoung-Jin JANG ; Soon Ho YOON
Korean Journal of Radiology 2026;27(2):174-185
Objective:
To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors.
Materials and Methods:
A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings.
Results:
In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%–40% (P = 0.14).The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%–47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts.
Conclusion
DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.
5.Comparative Outcomes of No-Touch Radiofrequency Ablation Versus Tumor-Puncture Microwave Ablation for Small Hepatocellular Carcinoma
Jae Hyun KIM ; Sae-Jin PARK ; Dong Jin CHUNG ; Hyun Pyo HONG ; Jeong Kyong LEE ; Chang Jin YOON ; Jeong Min LEE
Korean Journal of Radiology 2026;27(1):34-47
Objective:
This study aimed to compare the therapeutic outcomes of no-touch (NT) radiofrequency ablation (RFA) vs. tumorpuncture microwave ablation (MWA) in the treatment of single hepatocellular carcinomas (HCCs) measuring ≤3 cm.
Materials and Methods:
This multicenter retrospective study included 304 patients who underwent either NT-RFA (n = 144) or MWA (n = 160) for a single HCC measuring ≤3 cm. Comparative analyses were conducted for the overall cohort, while 81 patients per group were matched using propensity score matching (PSM). The analyzed outcomes included technical success, primary technique efficacy, local tumor progression (LTP), and major complications. Cumulative LTP was estimated using Kaplan–Meier analysis and compared using the log-rank text, while the rate of ablative margin ≥5 mm and ablation time were compared using Chi-squared and Mann–Whitney U tests, respectively.
Results:
Technical success was achieved in 98.6% (142/144) and 100% (160/160) of in the NT-RFA and MWA patients, respectively before PSM (P = 0.224), and 98.8% (80/81) and 100% (81/81) after PSM (P = 1.000). The primary technique efficacies were 98.6% (142/144) and 100% (160/160) before PSM (P = 0.224), and 97.5 % (79/81) and 100% (81/81) after PSM (P = 0.497), respectively. The 1-, 2-, and 3-year cumulative LTP rates were 1.4%, 1.4%, and 2.3%, respectively, for NTRFA and 5.1%, 8.6%, and 8.6%, respectively, for MWA before PSM (P = 0.013). After PSM, the corresponding rates were 0%, 0%, and 0% for NT-RFA, and 7.6%, 10.4%, and 10.4% for MWA (P = 0.006). Major complications were not observed. NT-RFA achieved a higher proportion, with an ablative margin ≥5 mm (88.7% [126/142] vs. 71.9% [115/160]; P < 0.001), but required longer ablation times (median, 10.0 vs. 6.0 min; P < 0.001).
Conclusion
NT-RFA showed superior local tumor control compared to MWA, despite greater procedural complexity and longer ablation times.
6.Thermal modulation and airflow distribution determine hair drying efficiency, moisture behavior in human hair in Republic of Korea: an ex vivo study
Tae-Rin KWON ; Doohyun HAN ; Hyoung Jun KIM ; Jungwook KIM ; Byung Ho YOON ; Sung Yong PARK ; Jun-Seok LEE ; Na Mi BYUN ; Jungkwan LEE ; Jungwon LEE ; Kwang Ho YOO
Medical Lasers 2026;15(1):69-76
Background:
Hair drying is a routine cosmetic practice; however, excessive heat exposure and non-uniform airflow can compromise cuticle integrity, degrade hair sensory properties, and induce scalp discomfort. This study aimed to (i) identify a practical thermal window that minimizes perturbation of hair fiber surface and quantify late-stage thermal amplification during the drying process using percentage-based analysis.
Methods:
Temperature-dependent hair fiber surface morphology was examined by scanning electron microscopy (SEM) after controlled exposure to 41°C, 60°C, 80°C, and 90°C using virgin and chemically damaged hair. The drying efficacy was assessed using the surface and internal moisture indices under airflow shaping (test) and uniform airflow (control) conditions. Hair fluttering (maximum angular displacement) was evaluated before and after drying under warm-cool alternating (60°C-80°C) versus constant hot airflow (80°C).
Results:
SEM revealed temperature-dependent cuticle disruption, with markedly greater surface perturbation at 90°C than at 80°C. Infrared thermography demonstrated pronounced late-stage thermal amplification: at 150 seconds, the surface temperature increased by 295% (from 24.2°C to 72.0°C) at 90°C, compared with 207% (from 24.2°C to 50.7°C) at 80°C. Airflow shaping promoted preferential surface moisture removal (–13.6%) while limiting internal dehydration (–9.4%), whereas the control condition exhibited minimal surface drying (–4.6%) but substantial internal moisture loss (–22.2%). Warm-cool modulation increased hair fluttering by +11.0%, whereas constant hot airflow reduced it (–3.7%).
Conclusion
These findings indicate that spatial and temporal control of heat delivery represents a clinically relevant design strategy beyond the nominal temperature specification in hair-drying devices.
7.Nicotinamide mononucleotide attenuates hepatic endoplasmic reticulum stress and modulates circadian rhythms in young mice with diet-induced obesity
So Young KWON ; Khuhee NA ; Yerim HAN ; Seungmin SONG ; Yoon Jung PARK
Nutrition Research and Practice 2026;20(2):220-238
BACKGROUND/OBJECTIVES:
Supplementation of nicotinamide adenine dinucleotide (NAD) precursors has been investigated for its potential to counteract age-related physiological decline. While decreased NAD + level is associated with conditions such as obesity and dyslipidemia, few studies have explored its metabolic impact in relatively young animals.Here, we hypothesized that nicotinamide mononucleotide (NMN) could alleviate highfat diet-induced metabolic stress in young mice and sought to elucidate the underlying mechanisms.MATERIALS/METHODS: We first conducted a secondary analysis of hepatic transcriptome datasets from multiple NMN intervention studies to identify target pathways. Next, 11-weekold lean and obese C57BL/6N mice administrated NMN (500 mg/kg/day) for 1 mon were analyzed for metabolic parameters and gene expression for the target pathways. In vitro study using AML12 cell line was then conducted to confirm the effects of NMN. Additionally, transcriptomic data from liver-specific nicotinamide phosphoribosyltransferase (NAMPT)-deficient mice were analyzed to examine the relationship between NAD + metabolism, endoplasmic reticulum (ER) stress, and circadian rhythm.
RESULTS:
The secondary analysis of hepatic transcriptome datasets revealed potential target pathways related to circadian regulation and hepatic ER stress. In mouse study, short-term NMN administration significantly decreased body weight and fat mass. NMN also alleviated hepatic ER stress response in vivo and in vitro. Additional analysis revealed that the mice with diet-induced metabolic stress or NAMPT deficiency led to phase shifts of the hepatic circadian core clock oscillation by advancing the peak time, while time-restricted feeding shifted the opposite, indicating the metabolic regulation of the circadian phase.
CONCLUSION
Short-term NMN administration effectively attenuated obese condition in young mice and mitigated hepatic ER stress. The altered ER stress was regulated by NAMPT, potentially through the phase shift of the hepatic circadian rhythm.
8.Postpartum bone mineral density in Korean women: associations with lactation status and calcium intake
Cheawon LEE ; Hangyeol JEON ; Yoon Ha KIM ; Myeong Gyun CHOI ; Jong Woon KIM ; Clara Yongjoo PARK
Nutrition Research and Practice 2026;20(1):145-155
BACKGROUND/OBJECTIVES:
Postpartum bone metabolism undergoes substantial alterations based on breastfeeding status. Research on maternal calcium intake and bone recovery, particularly among Asian women, remains limited. This study investigated postpartum change in bone mineral density (BMD) and its association with calcium intake during late pregnancy and post-delivery according to breastfeeding status.
SUBJECTS/METHODS:
Thirty-six women (22 breastfeeding, 14 non-breastfeeding) underwent dual-energy X-ray absorptiometry 3 times: 1) within 3 days of delivery, 2) at 6 mon postpartum for non-breastfeeding women or within 1 mon of weaning for breastfeeding women, and 3) at 12 mon postpartum. Dietary calcium intake was evaluated using a food frequency questionnaire and dietary supplement survey at all visits. Association between calcium intake with percentage change in BMD (%ΔBMD) was assessed by linear regression.
RESULTS:
The BMD at the lumbar spine, total hip, femoral neck, and trochanter significantly decreased during breastfeeding, whereas non-breastfeeding women displayed increased BMD at the femoral neck at 6 mon postpartum. In non-breastfeeding women, postpartum calcium intake was positively associated with %ΔBMD at the total hip, femoral neck, and intertrochanter (P < 0.05). Few significant associations were observed between %ΔBMD and late pregnancy intakes across all women, regardless of breastfeeding status. At 12 mon, BMD in breastfeeding women recovered to delivery levels, while non-breastfeeding women maintained their BMD observed at 6 mon postpartum.
CONCLUSION
Postpartum calcium intake is positively associated with bone recovery in non-breastfeeding women, suggesting that its effects on bone recovery potentially vary with lactation status.
9.Topical Application of Probiotic-Derived EGF From Pediococcus pentosaceus Improves UVB-Induced Photoaging in Hairless Mice
Yoon Jin ROH ; Yoon Hwan LEE ; Sun Young YUH ; Hye Won SONG ; Do Yeon KWON ; Byung Chull AN ; Yongku RYU ; Myung Jun CHUNG ; Kui Young PARK
Annals of Dermatology 2026;38(3):191-201
Background:
Epidermal growth factor (EGF) is widely applied in dermatology for its regenerative effects; however, its clinical utility is limited by low stability and high production costs.To overcome these limitations, we developed a novel probiotic-derived epidermal growth factor (pEGF) by engineering Pediococcus pentosaceus CBT SL4 to express and secrete EGF.
Objective:
To investigate the anti-photoaging effects of topical pEGF in a ultraviolet B (UVB)-irradiated mice by assessing histological and molecular changes related to collagen synthesis, extracellular matrix (ECM) remodeling, oxidative stress, and inflammation.
Methods:
SKH1 hairless mice were exposed to UVB for twelve weeks to induce photoaging and treated with topical 10% pEGF cream from week 9 to 12. Skin samples were analyzed using dermoscopy, histology, immunohistochemistry, quantitative real-time polymerase chain reaction, western blotting, and proteomics to evaluate morphological and molecular alterations in ECM components and inflammatory markers.
Results:
Topical pEGF treatment improved skin texture and reduced wrinkles. Histological evaluation revealed that EGF significantly attenuated UVB-induced epidermal thickening and restored collagen density, with the strongest effects observed in the pEGF group. Molecular analysis showed downregulation of matrix metalloproteinases (MMPs; MMP-1, MMP-3), upregulation of collagen (type I collagen, type III collagen) and tissue inhibitors of metalloproteinases (TIMPs; TIMP-1, TIMP-2). Additionally, pEGF reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β) and oxidative stress markers.
Conclusion
pEGF demonstrated potent anti-photoaging effects through ECM restoration, inflammation modulation, and barrier reinforcement. These findings support the therapeutic potential of pEGF as a stable, cost-effective alternative to conventional EGF in dermatological applications.
10.Eligibility and causes of disqualification among living liver donor candidates: A single-center analysis of 991 candidates
Eun-Ju NAM ; Jong-Hyun KIM ; Hae-In SHIN ; Young-In YOON ; Deok-Bog MOON ; Ki-Hun KIM ; Tae-Yong HA ; Gi-Won SONG ; Dong-Hwan JUNG ; Gil-Chun PARK ; Shin HWANG ; Sung-Gyu LEE
Annals of Liver Transplantation 2026;6(1):17-24
Background:
A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period.
Methods:
We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression.
Results:
Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated.
Conclusion
In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.

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