• Korean Journal of Radiology
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• v.22 no.5
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• pp.688-698
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• 2021

Objective: To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS). Materials and Methods: The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements. Results: Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm³; 95% confidence interval [CI], 4.9-24.3 mm³); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 mm³; 95% CI, -9.1-7.7 mm³). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm²; 95% CI, 0.89-1.25 mm²) but not in the larger lumen area group (mean of difference, -0.07 mm²; 95% CI, -0.22-0.08 mm²). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm²; 95% CI, 0.27-0.65 mm²) than in that of IVUS and SATM (1.53 mm²; 95% CI, 1.27-1.79 mm²). Conclusion: SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.

• Korean Journal of Radiology
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• v.22 no.8
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• pp.1240-1252
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• 2021

Objective: To compare the accuracy for detecting breast cancer in the diagnostic setting between the use of digital breast tomosynthesis (DBT), defined as DBT alone or combined DBT and digital mammography (DM), and the use of DM alone through a systematic review and meta-analysis. Materials and Methods: Ovid-MEDLINE, Ovid-Embase, Cochrane Library and five Korean local databases were searched for articles published until March 25, 2020. We selected studies that reported diagnostic accuracy in women who were recalled after screening or symptomatic. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random effects model was used to estimate pooled sensitivity and specificity. We compared the diagnostic accuracy between DBT and DM alone using meta-regression and subgroup analyses by modality of intervention, country, existence of calcifications, breast density, Breast Imaging Reporting and Data System category threshold, study design, protocol for participant sampling, sample size, reason for diagnostic examination, and number of readers who interpreted the studies. Results: Twenty studies (n = 44513) that compared DBT and DM alone were included. The pooled sensitivity and specificity were 0.90 (95% confidence interval [CI] 0.86-0.93) and 0.90 (95% CI 0.84-0.94), respectively, for DBT, which were higher than 0.76 (95% CI 0.68-0.83) and 0.83 (95% CI 0.73-0.89), respectively, for DM alone (p < 0.001). The area under the summary receiver operating characteristics curve was 0.95 (95% CI 0.93-0.97) for DBT and 0.86 (95% CI 0.82-0.88) for DM alone. The higher sensitivity and specificity of DBT than DM alone were consistently noted in most subgroup and meta-regression analyses. Conclusion: Use of DBT was more accurate than DM alone for the diagnosis of breast cancer. Women with clinical symptoms or abnormal screening findings could be more effectively evaluated for breast cancer using DBT, which has a superior diagnostic performance compared to DM alone.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.178-188
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• 2024

The dynamics of suspended sediment (SS) in forested catchments vary depending upon human or natural disturbances, including land use change, forestry activity, forest fires, and landslides. Understanding the dynamics of SS originating from the potential sources within a forested catchment is crucial for establishing an effective water quality management strategy. Therefore, to suggest a systematic method for interpreting SS dynamics, we evaluated the performance and applicability of ten methods for calculating the hysteresis index based on observed hydrological data and two calculation models (Lawler's method and Lloyd's method) with five sampling intervals (50th, 25th, 10th, 5th, and 1st percentiles). Our results showed that Lloyd's method, which used a sampling interval at the 1st percentile, had the largest number of analyzable runoff events and exhibited the best performance. The results of this study can contribute to quantifying the hysteresis in the relationship between discharge and SS and provide useful information for interpreting SS dynamics.

• Korean Journal of Radiology
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• v.24 no.5
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• pp.454-464
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• 2023

Objective: We aimed to investigate current expectations and clinical adoption of artificial intelligence (AI) software among neuroradiologists in Korea. Materials and Methods: In April 2022, a 30-item online survey was conducted by neuroradiologists from the Korean Society of Neuroradiology (KSNR) to assess current user experiences, perceptions, attitudes, and future expectations regarding AI for neuro-applications. Respondents with experience in AI software were further investigated in terms of the number and type of software used, period of use, clinical usefulness, and future scope. Results were compared between respondents with and without experience with AI software through multivariable logistic regression and mediation analyses. Results: The survey was completed by 73 respondents, accounting for 21.9% (73/334) of the KSNR members; 72.6% (53/73) were familiar with AI and 58.9% (43/73) had used AI software, with approximately 86% (37/43) using 1-3 AI software programs and 51.2% (22/43) having up to one year of experience with AI software. Among AI software types, brain volumetry software was the most common (62.8% [27/43]). Although 52.1% (38/73) assumed that AI is currently useful in practice, 86.3% (63/73) expected it to be useful for clinical practice within 10 years. The main expected benefits were reducing the time spent on repetitive tasks (91.8% [67/73]) and improving reading accuracy and reducing errors (72.6% [53/73]). Those who experienced AI software were more familiar with AI (adjusted odds ratio, 7.1 [95% confidence interval, 1.81-27.81]; P = 0.005). More than half of the respondents with AI software experience (55.8% [24/43]) agreed that AI should be included in training curriculums, while almost all (95.3% [41/43]) believed that radiologists should coordinate to improve its performance. Conclusion: A majority of respondents experienced AI software and showed a proactive attitude toward adopting AI in clinical practice, suggesting that AI should be incorporated into training and active participation in AI development should be encouraged.

• Korean Journal of Radiology
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• v.24 no.5
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• pp.424-433
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• 2023

Objective: To assess the safety and efficacy of balloon dilatation under dual guidance using fluoroscopy and bronchoscopy for treating bronchial stenosis following lung transplantation (LT), and to elucidate the factors associated with patency after the procedure. Materials and Methods: From September, 2012, to April, 2021, 50 patients (mean age ± standard deviation, 54.4 ± 12.2 years) with bronchial stenosis among 361 recipients of LT were retrospectively analyzed. The safety of balloon dilatation was assessed by evaluating procedure-related complications. Efficacy was assessed by evaluating the technical success, primary patency, and secondary patency. Primary and secondary cumulative patency rates were calculated using the Kaplan-Meier method. The factors associated with patency after the procedure were evaluated using multivariable Cox hazard proportional regression analysis. Results: In total, 65 bronchi were treated with balloon dilatation in 50 patients. The total number of treatment sessions was 277 and the technical success rate was 99.3% (275/277 sessions). No major procedure-related complications were noted. During the mean follow-up period of 34.6 ± 30.8 months, primary patency was achieved in 12 of 65 bronchi (18.5%). However, the patency rate improved to 76.9% (50 of 65 bronchi) after repeated balloon dilatation (secondary patency). The 6-month, 1-year, 3-year, and 5-year secondary patency rates were 95.4%, 90.8%, 83.1%, and 78.5%, respectively. The presence of clinical symptoms was a significant prognostic factor associated with reduced primary patency (adjusted hazard ratio [HR], 0.465; 95% confidence interval [CI], 0.220-0.987). Early-stage treatment ≤ 6 months (adjusted HR, 3.588; 95% CI, 1.093-11.780) and prolonged balloon dilatation > 5 min (adjusted HR, 3.285; 95% CI, 1.018-10.598) were associated with significantly higher secondary patency. Conclusion: Repeated balloon dilatation was determined to be safe and effective for treating bronchial stenosis following LT. Early-stage treatment and prolonged balloon dilatation could significantly promote long-term patency.

• Korean Journal of Radiology
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• v.23 no.12
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• pp.1241-1250
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• 2022

Objective: To conduct a simulation study to determine whether artificial intelligence (AI)-aided mammography reading can reduce unnecessary recalls while maintaining cancer detection ability in women recalled after mammography screening. Materials and Methods: A retrospective reader study was performed by screening mammographies of 793 women (mean age ± standard deviation, 50 ± 9 years) recalled to obtain supplemental mammographic views regarding screening mammography-detected abnormalities between January 2016 and December 2019 at two screening centers. Initial screening mammography examinations were interpreted by three dedicated breast radiologists sequentially, case by case, with and without AI aid, in a single session. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and recall rate for breast cancer diagnosis were obtained and compared between the two reading modes. Results: Fifty-four mammograms with cancer (35 invasive cancers and 19 ductal carcinomas in situ) and 739 mammograms with benign or negative findings were included. The reader-averaged AUC improved after AI aid, from 0.79 (95% confidence interval [CI], 0.74-0.85) to 0.89 (95% CI, 0.85-0.94) (p < 0.001). The reader-averaged specificities before and after AI aid were 41.9% (95% CI, 39.3%-44.5%) and 53.9% (95% CI, 50.9%-56.9%), respectively (p < 0.001). The reader-averaged sensitivity was not statistically different between AI-unaided and AI-aided readings: 89.5% (95% CI, 83.1%-95.9%) vs. 92.6% (95% CI, 86.2%-99.0%) (p = 0.053), although the sensitivities of the least experienced radiologists before and after AI aid were 79.6% (43 of 54 [95% CI, 66.5%-89.4%]) and 90.7% (49 of 54 [95% CI, 79.7%-96.9%]), respectively (p = 0.031). With AI aid, the reader-averaged recall rate decreased by from 60.4% (95% CI, 57.8%-62.9%) to 49.5% (95% CI, 46.5%-52.4%) (p < 0.001). Conclusion: AI-aided reading reduced the number of recalls and improved the diagnostic performance in our simulation using women initially recalled for supplemental mammographic views after mammography screening.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.48.1-48.13
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• 2023

Background: This study was conducted to identify the success rate for smoking cessation over time after participation in a therapeutic smoking cessation camp, and to identify how participant characteristics, including a supportive workplace environment for smoking cessation (SWESC), affect the success rate for smoking cessation. Methods: In all, 296 participants at smoking cessation camps in Ulsan between 2015 and 2020 were investigated. The success rates of smoking cessation after weeks 4, 6, 12, and 24 at camp were investigated. The participants were grouped as workers with an SWESC, and workers without an SWESC, and variables (age, education, household income, marital status, drinking, exercise, body mass index, morbidity, job, number of counseling sessions, cigarettes smoked per day and smoking initiation age) were investigated. Multiple logistic regression analysis was conducted at each time point. In addition, Cox regression analysis was performed to evaluate the variables affecting the success rate for smoking cessation over time. Results: The smoking cessation success rate of workers with an SWESC at week 24 (90.7%) was higher than that for workers without an SWESC (60.5%). Multiple logistic regression was performed to determine the relationship between each variable and the success rates for smoking cessation at week 6, 12, and 24. SWESC was confirmed as significant (p < 0.05) variables for increased success rate for smoking cessation at all 3 time points. After adjusting for all variables, the Cox proportional hazards survival analysis showed a hazard ratio of 6.17 for SWESC (p < 0.001,; 95% confidence interval: 3.08-12.38). Conclusions: At a professional treatment smoking cessation camp, participants with an SWESC showed a significantly higher success rate for smoking cessation. Supportive workplace environment for workers' health is expected to be an important factor for smoking cessation projects as well as other health promotion projects at workplace.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.27.1-27.12
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• 2023

Background: Environmental exposure is characterized by low concentration, chronic, and complex exposure. Traditional epidemiological studies show limitations in reflecting these characteristics since they usually focus on a single or very limited number of exposure factors at a time. In this study, we adopted the methodology of environment-wide association study (EWAS) to figure out the association of human liver function with various environmentally hazardous substances. Methods: We analyzed 2,961 participants from the Korean National Environmental Health Survey Cycle 4 (2018-2020). Using generalized linear model (GLM) analysis, we analyzed the association of 72 variables with 3 liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma glutamyl transferase [GGT]). Finally, we visualized our results with Manhattan plot. Results: In GLM analysis, perfluorooctanesulfonate were positively associated with ALT (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.39-3.46; p_adjusted = 0.0147) and perfluorodecanoic acid showed positive association with GGT (OR: 2.73; 95% CI: 1.36-5.5; p_adjusted = 0.0256). Plasma mercury showed positive association with GGT (OR: 1.45; 95% CI: 1.14-1.84; p_adjusted = 0.0315). Using a plastic container while keeping food in the refrigerator was associated with elevated GGT compared to using a glass container (OR: 1.51; 95% CI: 1.16-1.95; p_adjusted = 0.0153). 2-ethyl-5-oxohexyl phthalate, showed a negative trend with all 3 indices, with AST (OR: 0.54; 95% CI: 0.39-0.73; p_adjusted = 0.00357), ALT (OR: 0.5; 95% CI: 0.34-0.75; p_adjusted = 0.036), GGT (OR: 0.55; 95% CI: 0.4-0.76; p_adjusted = 0.00697). Bisphenol S and frequent use of sunblock cream showed negative association with ALT (OR: 0.77; 95% CI: 0.66-0.89), and GGT (OR: 0.25; 95% CI: 0.11-0.55), respectively. Conclusions: We conducted an exploratory study on environmental exposure and human liver function. By using EWAS methodology, we identified 7 factors that could have potential association with liver function.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.3
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• pp.258-263
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• 2023

Backgrounds/Aims: Hemangiomas are the most common benign liver lesions; however, they are usually asymptomatic and seldom require surgery. Enucleation and resection are the most commonly performed surgical procedures for symptomatic lesions. This study aims to compare the outcomes of these two surgical techniques. Methods: A retrospective analysis of symptomatic hepatic hemangiomas (HH) operated upon between 2000 and 2021. Patients were categorized into the enucleation and resection groups. Demographic profile, intraoperative bleeding, and morbidity (Clavien-Dindo Grade) were compared. Independent t-test and chi-square tests were used for continuous and categorical variables respectively. p-value of < 0.05 was considered significant. Results: Sixteen symptomatic HH patients aged 30 to 66 years underwent surgery (enucleation = 8, resection = 8) and majority were females (n = 10 [62.5%]). Fifteen patients presented with abdominal pain, and one patient had an interval increase in the size of the lesion from 9 to 12 cm. The size of hemangiomas varied from 6 to 23 cm. The median blood loss (enucleation: 350 vs. resection: 600 mL), operative time (enucleation: 5.8 vs. resection: 7.5 hours), and postoperative hospital stay (enucleation: 6.5 vs. resection: 11 days) were greater in the resection group (statistically insignificant). In the resection group, morbidity was significantly higher (62.6% vs. 12.5%, p = 0.05), including one mortality. All patients remained asymptomatic during the follow-up. Conclusions: Enucleation was simpler with less morbidity as compared to resection in our series. However, considering the small number of patients, further studies are needed with comparable groups to confirm the superiority of enucleation over resection.

• Clinical Nutrition Research
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• v.12 no.4
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• pp.283-292
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• 2023

The aim of this study was to investigate whether dairy intake was associated with the severity of coronavirus disease 2019 (COVID-19) disease and the probability of hospitalization of patients. This cross-sectional study was conducted on 141 patients with COVID-19 with an average age of 46.23 ± 15.88 years. The number of men (52.5%) participating in this study was higher than that of women. The association between dairy intake and COVID-19 was evaluated by multivariable logistic regression analysis. The risk of hospitalization in the highest tertile of dairy intake was 31% lower than in the lowest tertile (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.37-1.25, p trend = 0.023). Higher milk and yogurt intake was associated with a reduced risk of hospitalization due to COVID-19. Patients in the third tertiles were about 65% (p for trend = 0.014) and 12% (p for trend = 0.050) less likely to be hospitalized than those in the first tertile, respectively. Dairy consumption, especially low-fat ones, was associated with a lower risk of hospitalization due to COVID-19 and lower severity of COVID-19.