The 2022 Annual Report on Toxicology Surveillance and Severe Poisoning Cases at Emergency Departments in Korea

Purpose@#This study investigated the actual incidence of acute poisoning in Korea on a nationwide scale, with the aim of laying the groundwork for future initiatives in prevention, strategic antidote distribution, and the development of effective emergency treatment for acute poisoning. @*Methods@#The study analyzed data from 3,038 patients who presented to emergency departments with poisoning-related conditions from June 1, 2022 to December 31, 2022 at 10 sites in nine cities across the country. We extracted data on general characteristics of the poisoning cases, including demographic characteristics (age and gender), place of exposure, reason for poisoning, route of exposure, and the substance involved in the poisoning incident. Age-related patterns in reasons for poisoning, medical outcomes, frequent and primary poisoning substances, and deaths were also analyzed. @*Results@#The population analyzed in our study was predominantly female, with women constituting 54.74% of all cases. Among infants and children, non-intentional poisoning due to general accidents was the most common cause, accounting for 71.43% of cases. Conversely, suicidal poisoning was more prevalent among teenagers and adults over 20. Fifty-two patients died during the study period, with males comprising approximately two-thirds (67.31%) of these fatalities. Pesticides were the most common poisoning substance among those who died, accounting for 55.77% of such cases. Notably, a significant majority of the victims were elderly individuals aged 60 and above. @*Conclusion@#This study holds substantial significance, since it represents the first comprehensive investigation and analysis of the symptoms, treatment, and causes of death due to poisoning in Korea on a national scale. By substantially expanding the range and types of poisonous substances examined, we were able to more precisely identify the characteristics and clinical patterns of poisoning cases nationwide.

Relationship Between MicroRNA Signature and Arterial Stiffness in Patients With Ischemic Stroke

Background@#and Purpose We investigated whether circulating microRNAs (miRNAs) is associated with arterial stiffness in patients with acute ischemic stroke. @*Methods@#We recruited patients with acute ischemic stroke who were admitted to a university hospital stroke center and underwent carotid-femoral pulse wave velocity (cfPWV) measurement using SphygmoCor (AtCor Medical, Sydney, Australia) and brachial-ankle PWV using a volume-plethysmography device (VP-1000, Omron Colin, Komaki, Japan). Circulating miRNAs were measured in venous blood samples stored in EDTA. We selected five miRNAs (miR-17, miR-93, miR-450, miR-629, and let-7i) related to atherosclerosis based on a literature review. Pearson’s correlation analysis was applied to the correlations between miRNAs and arterial stiffness parameters. Finally, multivariable linear regression analysis was performed to identify the independent factors for cfPWV. @*Results@#This study included 70 patients (age=71.1±10.3 years [mean±SD], 29 females). The expression levels of miR-93 (r=-0.27, p=0.049) and let-7i ((r=-0.27, p=0.039) were inversely correlated with cfPWV. Multivariable linear regression analysis including age, hypertension, and estimated glomerular filtration rate showed that let-7i was independently related with cfPWV (standardized coefficient=-0.262, p=0.036). Correlation analysis indicated that let-7i was positively associated with visceral muscle Hounsfield units on computed tomography ((r=0.264, p=0.043). @*Conclusions@#The expression level of let-7i was independently related to arterial stiffness in patients with cerebral infarction, suggesting that it plays a pathophysiological role in atherosclerosis.

Severity of hyperechoic pancreas on ultrasonography as a risk factor for glycemic progression

Purpose@#The aim of this study was to evaluate the association between the severity of hyperechoic pancreas (HP) on ultrasonography (US) and glycemic progression. @*Methods@#In total, 1,386 participants who underwent abdominal US as part of health examinations between December 2008 and May 2014 were included in this retrospective study. We classified pancreatic echogenicity on a 4-point scale, and compared it using two distinct criteria: fatty pancreas (FP) 1 criterion (normal vs. ≥mild HP) and FP2 criterion (normal/mild HP vs. ≥moderate HP). According to the presence of nonalcoholic fatty liver disease (NAFLD), participants were subdivided into four groups: non-NAFLD and non-HP, isolated NAFLD, isolated HP, and HP with NAFLD. Glycemic progression was defined as progression from normoglycemia to prediabetes or diabetes or progression from prediabetes to diabetes. @*Results@#During the follow-up (median, 5.9 years), 262 of the 1,386 participants developed glycemic progression. Using FP2, the probability of glycemic progression across the four subgroups showed cumulative aggravation for NAFLD and HP (all P<0.05). Isolated HP showed a higher probability of glycemic progression than isolated NAFLD according to FP2 (P<0.001). The highest probability of glycemic progression was observed in patients with both NAFLD and HP (P<0.001). The hazard ratio for glycemic progression increased with the severity of HP. @*Conclusion@#Increasing severity of HP on US was found to be significantly correlated with glycemic progression. Moreover, isolated HP of moderate or greater severity predicted glycemic progression independent of NAFLD.

Quantitative ultrasound radiofrequency data analysis for the assessment of hepatic steatosis using the controlled attenuation parameter as a reference standard

Purpose@#This study was aimed to investigate the value of quantitative ultrasound (US) parameters from radiofrequency (RF) data analysis for assessing hepatic steatosis, using controlled attenuation parameter (CAP)-based steatosis grades as the reference standard. @*Methods@#We analyzed 243 participants with both B-mode liver US with RF data acquisition and CAP measurements. On B-mode US images, hepatic steatosis was visually scored (0/1/2/3, none/mild/moderate/severe), and the hepatorenal index (HRI) was calculated. From the RF data analysis, the tissue scatter-distribution imaging parameter (TSI-p) and tissue attenuation imaging parameter (TAI-p) of the liver parenchyma were measured. US parameters were correlated with CAP-based steatosis grades (S0/1/2/3, none/mild/moderate/severe) and their diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Multivariate linear regression analysis was performed to identify determinants of TSI-p and TAI-p. @*Results@#Participants were classified as having S0 (n=152), S1 (n=54), S2 (n=14), and S3 (n=23) on CAP measurements. TSI-p and TAI-p were significantly correlated with steatosis grades (ρ =0.593 and ρ=-0.617, P<0.001 for both). For predicting ≥S1, ≥S2, and S3, the areas under the ROC curves (AUCs) of TSI-p were 0.827/0.914/0.917; TAI-p, 0.844/0.914/0.909; visual scores, 0.659/0.778/0.794; and HRI, 0.629/0.751/0.759, respectively. TSI-p and TAI-p had significantly higher AUCs than did visual scores or HRI for ≥S1 or ≥S2 (P≤0.003). In the multivariate analysis, the transient elastography-based fibrosis grade (P=0.034) and steatosis grade (P<0.001) were independent determinants of TSI-p, while steatosis grade (P<0.001) was an independent determinant of TAI-p. @*Conclusion@#TSI-p and TAI-p derived from US RF data may be useful for detecting hepatic steatosis and assessing its severity.

Reciprocal Prediction between Impulsivity and Problematic Internet Use among North Korean Refugee Youths in South Korea by Gender and Adverse Childhood Experience

Objective@#North Korean refugee youths are at higher risk of developing a wide array of psychosocial sequelae, including increased impulsivity and problematic internet use. We aimed to identify reciprocal temporal relationships by performing autoregressive cross-lagged modeling and to examine how these relations differ by gender and adverse childhood experience. @*Methods@#We used the follow-up data of 108 North Korean refugee youths in South Korea over a 1-year period. The Barratt Impulsivity Scale-Brief and Young’s Internet Addiction Test were used to assess impulsivity and problematic internet use, respectively. @*Results@#Autoregressive effects were significant across all groups, indicating that impulsivity and problematic internet use were stable across time; however, prospective prediction of problematic internet use from impulsivity was not significant across all groups. Problematic internet use at baseline positively predicted impulsivity at after 1 year of follow up in only males and individuals with adverse childhood experience. @*Conclusion@#Our findings suggest that the negative effect of problematic internet use (i.e., increased impulsivity) among North Korean refugee youths may be more profound in males and those with adverse childhood experience. We present possible explanations for these findings and discuss the implications for targeted interventions.

The Association between Unstable Employment and Suicidal Behavior in Young-Adult Precarious Workers

Objective@#Precarious workers have increased over the past two decades in South Korea. Employment instability, especially among young adults, is considered a serious social problem. The unstable employment status of precarious workers has negative impacts on their mental health, such as suicidal behavior. This study aims to identify the effect of the unstable employment conditions on the suicidal behavior of precarious workers. @*Methods@#An online survey was conducted with a panel sample of South Korean adults (n=797) who were precarious workers aged between 25–34 years. We applied Model 6 of SPSS PROCESS MACRO 3.5 to examine the multiple mediation effects of depression and anger in the relationship between employment instability and suicide. @*Results@#Unstable employment had no direct effect on suicidal behavior. The path of unstable employment to suicidal behavior via depression and anger had a significant indirect effect. However, employment and anger were negatively related. The indirect effect of depression and anger on the relation between unstable employment and suicidal behavior was statistically significant. @*Conclusion@#This study suggests an association between unstable employment and suicidal behavior, mediated by depression and anger. Specifically, a high level of unstable employment status increased depression. In contrast, a low level of unstable employment status increased anger, which ultimately led to an increase in suicidal behavior. These contrasting findings are likely to reflect the heterogeneity of precarious workers. Further longitudinal studies are necessary to identify the causality between precarious employment and suicidal behavior over time.

Radiologic Evaluation and Structured Reporting Form for Extrahepatic Bile Duct Cancer: 2019 Consensus Recommendations from the Korean Society of Abdominal Radiology

Radiologic imaging is important for evaluating extrahepatic bile duct (EHD) cancers; it is used for staging tumors and evaluating the suitability of surgical resection, as surgery may be contraindicated in some cases regardless of tumor stage. However, the published general recommendations for EHD cancer and recommendations guided by the perspectives of radiologists are limited.The Korean Society of Abdominal Radiology (KSAR) study group for EHD cancer developed key questions and corresponding recommendations for the radiologic evaluation of EHD cancer and organized them into 4 sections: nomenclature and definition, imaging technique, cancer evaluation, and tumor response. A structured reporting form was also developed to allow the progressive accumulation of standardized data, which will facilitate multicenter studies and contribute more evidence for the development of recommendations.

Reciprocal Prediction between Impulsivity and Problematic Internet Use among North Korean Refugee Youths in South Korea by Gender and Adverse Childhood Experience

Objective@#North Korean refugee youths are at higher risk of developing a wide array of psychosocial sequelae, including increased impulsivity and problematic internet use. We aimed to identify reciprocal temporal relationships by performing autoregressive cross-lagged modeling and to examine how these relations differ by gender and adverse childhood experience. @*Methods@#We used the follow-up data of 108 North Korean refugee youths in South Korea over a 1-year period. The Barratt Impulsivity Scale-Brief and Young’s Internet Addiction Test were used to assess impulsivity and problematic internet use, respectively. @*Results@#Autoregressive effects were significant across all groups, indicating that impulsivity and problematic internet use were stable across time; however, prospective prediction of problematic internet use from impulsivity was not significant across all groups. Problematic internet use at baseline positively predicted impulsivity at after 1 year of follow up in only males and individuals with adverse childhood experience. @*Conclusion@#Our findings suggest that the negative effect of problematic internet use (i.e., increased impulsivity) among North Korean refugee youths may be more profound in males and those with adverse childhood experience. We present possible explanations for these findings and discuss the implications for targeted interventions.

The Association between Unstable Employment and Suicidal Behavior in Young-Adult Precarious Workers

Objective@#Precarious workers have increased over the past two decades in South Korea. Employment instability, especially among young adults, is considered a serious social problem. The unstable employment status of precarious workers has negative impacts on their mental health, such as suicidal behavior. This study aims to identify the effect of the unstable employment conditions on the suicidal behavior of precarious workers. @*Methods@#An online survey was conducted with a panel sample of South Korean adults (n=797) who were precarious workers aged between 25–34 years. We applied Model 6 of SPSS PROCESS MACRO 3.5 to examine the multiple mediation effects of depression and anger in the relationship between employment instability and suicide. @*Results@#Unstable employment had no direct effect on suicidal behavior. The path of unstable employment to suicidal behavior via depression and anger had a significant indirect effect. However, employment and anger were negatively related. The indirect effect of depression and anger on the relation between unstable employment and suicidal behavior was statistically significant. @*Conclusion@#This study suggests an association between unstable employment and suicidal behavior, mediated by depression and anger. Specifically, a high level of unstable employment status increased depression. In contrast, a low level of unstable employment status increased anger, which ultimately led to an increase in suicidal behavior. These contrasting findings are likely to reflect the heterogeneity of precarious workers. Further longitudinal studies are necessary to identify the causality between precarious employment and suicidal behavior over time.

Added value of 2D shear wave imaging of the gallbladder bed of the liver for acute cholecystitis

Purpose@#The purpose of this study was to evaluate whether shear wave elastography (SWE) and the shear wave dispersion slope (SWD) obtained from 2-dimensional shear wave imaging (2D-SWI) of the gallbladder (GB) bed of the liver could be helpful in the diagnosis of acute cholecystitis. @*Methods@#We included 44 patients referred for abdominal ultrasonography (US) under the impression of acute cholecystitis from April 2018 to March 2019. Patients with chronic liver disease were excluded from this study. In addition to routine upper abdominal US, we performed 2D-SWI including liver stiffness measurements by SWE and SWD, which reflects tissue viscosity. 2D-SWI was performed at the GB bed of the liver through the right intercostal approach at least 3 times with different frames. We assessed typical US findings and the added value of 2D-SWI in diagnosing acute cholecystitis. Histopathologic results of surgical specimens were used as the standard of reference. If a surgical specimen was unavailable, a bile fluid test or clinical followup for more than 3 months served as the reference standard. @*Results@#The optimal cutoff values for SWE and SWD were 8 kPa and 10.9 (m/sec)/kHz, respectively. In the univariate analysis, SWE, GB distension, and sludge were predictive factors of acute cholecystitis. In the multivariate analysis, categorized SWE was the only significant predictor (P<0.01). By using 2D-SWI, the diagnostic performance of two readers did not significantly increase, although the inter-reader agreement improved (k=0.654-0.778). @*Conclusion@#2D-SWI of the GB bed of the liver could be helpful for diagnosing acute cholecystitis.

Abdominal Digital Radiography with a Novel Post-Processing Technique: Phantom and Patient Studies

Purpose@#The aim of this study was to evaluate the diagnostic image quality of low dose abdominal digital radiography processed with a new post-processing technique. @*Materials and Methods@#Abdominal radiographs from phantom pilot studies were post-processed by the novel and conventional post-processing methods of our institution; the proper dose for the subsequent patient study of 49 subjects was determined by comparing image quality of the two preceding studies. Two radiographs of each patient were taken using the conventional and derived dose protocols with the proposed post-processing method. The image details and quality were evaluated by two radiologists. @*Results@#The radiation dose for the patient study was derived to be half of the conventional method. Overall half-dose image quality with the proposed method was significantly higher than that of the conventional method (p < 0.05) with moderate inter-rater agreement (κ = 0.60, 0.47). @*Conclusion@#By applying the new post-processing technique, half-dose abdominal digital radiography can demonstrate feasible image quality compared to the full-dose images.

Two-Dimensional-Shear Wave Elastography with a Propagation Map: Prospective Evaluation of Liver Fibrosis Using Histopathology as the Reference Standard

Objective@#The aim of this study was to prospectively evaluate whether liver stiffness (LS) assessments, obtained by twodimensional (2D)-shear wave elastography (SWE) with a propagation map, can evaluate liver fibrosis stage using histopathology as the reference standard. @*Materials and Methods@#We prospectively enrolled 123 patients who had undergone percutaneous liver biopsy from two tertiary referral hospitals. All patients underwent 2D-SWE examination prior to biopsy, and LS values (kilopascal [kPa]) were obtained. On histopathologic examination, fibrosis stage (F0–F4) and necroinflammatory activity grade (A0–A4) were assessed. Multivariate linear regression analysis was performed to determine the significant factors affecting the LS value.The diagnostic performance of the LS value for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis, and the optimal cut-off value was determined by the Youden index. @*Results@#Reliable measurements of LS values were obtained in 114 patients (92.7%, 114/123). LS values obtained from 2D-SWE with the propagation map positively correlated with the progression of liver fibrosis reported from histopathology (p < 0.001). According to the multivariate linear regression analysis, fibrosis stage was the only factor significantly associated with LS (p < 0.001). The area under the ROC curve of LS from 2D-SWE with the propagation map was 0.773, 0.865, 0.946, and 0.950 for detecting F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The optimal cut-off LS values were 5.4, 7.8, 9.4, and 12.2 kPa for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The corresponding sensitivity and specificity of the LS value for detecting cirrhosis were 90.9% and 88.4%, respectively. @*Conclusion@#The LS value obtained from 2D-SWE with a propagation map provides excellent diagnostic performance in evaluating liver fibrosis stage, determined by histopathology.

Two-Dimensional-Shear Wave Elastography with a Propagation Map: Prospective Evaluation of Liver Fibrosis Using Histopathology as the Reference Standard

Objective@#The aim of this study was to prospectively evaluate whether liver stiffness (LS) assessments, obtained by twodimensional (2D)-shear wave elastography (SWE) with a propagation map, can evaluate liver fibrosis stage using histopathology as the reference standard. @*Materials and Methods@#We prospectively enrolled 123 patients who had undergone percutaneous liver biopsy from two tertiary referral hospitals. All patients underwent 2D-SWE examination prior to biopsy, and LS values (kilopascal [kPa]) were obtained. On histopathologic examination, fibrosis stage (F0–F4) and necroinflammatory activity grade (A0–A4) were assessed. Multivariate linear regression analysis was performed to determine the significant factors affecting the LS value.The diagnostic performance of the LS value for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis, and the optimal cut-off value was determined by the Youden index. @*Results@#Reliable measurements of LS values were obtained in 114 patients (92.7%, 114/123). LS values obtained from 2D-SWE with the propagation map positively correlated with the progression of liver fibrosis reported from histopathology (p < 0.001). According to the multivariate linear regression analysis, fibrosis stage was the only factor significantly associated with LS (p < 0.001). The area under the ROC curve of LS from 2D-SWE with the propagation map was 0.773, 0.865, 0.946, and 0.950 for detecting F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The optimal cut-off LS values were 5.4, 7.8, 9.4, and 12.2 kPa for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The corresponding sensitivity and specificity of the LS value for detecting cirrhosis were 90.9% and 88.4%, respectively. @*Conclusion@#The LS value obtained from 2D-SWE with a propagation map provides excellent diagnostic performance in evaluating liver fibrosis stage, determined by histopathology.

Preventive Effects of Fluoride Gel Application on Dental Caries in the Permanent Tooth: A Systematic Review of Randomized Controlled Trials / 치위생과학회지

BACKGROUND: The purpose of this systematic review was to investigate the effects of topical fluoride gel application on dental caries prevention in the permanent teeth of children and adolescents. METHODS: We searched the EMBASE, PubMed, and Cochrane Library databases for randomized controlled trials (RCTs) assessing the effects of self-applied or professionally applied topical fluoride gels in patients <18 years of age; the search was completed on April 1, 2018. All included trials involved an experimental group (fluoride gel application) and a control group (placebo or no treatment). The outcome measures were the D(M)FS and D(M)FT indices, which were compared between the two groups. Review Manager software was used for quantitative synthesis of the final selected articles, and a forest plot was generated via a meta-analysis conducted using a random effects model. RESULTS: The results showed that the D(M)FS and D(M)FT indices were lower in the fluoride application group than in the control group, thus indicating that fluoride gel application was effective in dental caries prevention. We also performed a subgroup analysis to determine whether the effects of fluoride application differed if patients received oral prophylaxis (self or professional) before fluoride gel application. Therefore, the two groups showed slightly larger differences when studies without oral prophylaxis before fluoride gel application were considered; however, the difference was not statistically significant. CONCLUSION: These findings should be utilized to raise awareness about the caries-prevention effects of topical fluoride application among patients and guardians. Further RCTs should evaluate the effects of fluoride application with or without preceding oral prophylaxis, and appropriate fluoride application guidelines should be developed to maximize the effects of fluoride application in clinical practice.

Validation of a New Point Shear-Wave Elastography Method for Noninvasive Assessment of Liver Fibrosis: A Prospective Multicenter Study

OBJECTIVE: To validate the diagnostic value of a new point shear-wave elastography method, S-shearwave elastography (S-SWE; Samsung Medison Co., Ltd.), in noninvasive assessment of liver fibrosis. MATERIALS AND METHODS: In this prospective multicenter study, liver stiffness (LS) measurements for 600 participants were obtained with both S-SWE and transient elastography (TE). The rates of unsuccessful LS measurements in S-SWE and TE were compared, and correlations between S-SWE and TE measurements were assessed. In 107 patients with histologic reference data, the optimal LS cut-off values for predicting severe fibrosis and cirrhosis on S-SWE were determined using receiver operating characteristic (ROC) curve analysis. The LS cut-off values in S-SWE were then validated in 463 patients without histologic reference data by using TE values as the reference standard, and the sensitivity and specificity of the cut-off values for predicting severe fibrosis and cirrhosis were calculated. RESULTS: The frequency of unsuccessful LS measurements on TE (4.5%, 27/600) was significantly higher than that (0.7%, 4/600) on S-SWE (p < 0.001). LS measurements on S-SWE showed a significant correlation with TE values (r = 0.880, p < 0.001). In 107 patients with histological reference data, the areas under the ROC curves on S-SWE were 0.845 and 0.850, with optimal cut-offs of 7.0 kilopascals (kPa) and 9.7 kPa, for the diagnosis of severe fibrosis and cirrhosis, respectively. Using these cut-off values, S-SWE showed sensitivities of 92.9% and 97.4% and specificities of 89.5% and 83.1% in TE-based evaluations of severe fibrosis and cirrhosis, respectively. CONCLUSION: LS measurements on S-SWE were well correlated with those on TE. In addition, S-SWE provided good diagnostic performance for staging of hepatic fibrosis, with a lower rate of unsuccessful LS measurements compared with TE.

Risk Factors for Brain Damage in Preterm Infants After Late-Onset Circulatory Collapse Events

PURPOSE: This study aimed to identify risk factors for brain damage in infants with late-onset circulatory collapse (LCC), a circulatory failure that responds to glucocorticoid therapy. METHODS: We retrospectively reviewed 167 infants (gestational age < 35 weeks) who had hypotension between April 2009 and March 2017 at Boramae Medical Center. Forty infants were diagnosed with LCC and divided into two groups based on ultrasonography and magnetic resonance imaging findings: infants with periventricular leukomalacia (n=9) and those with normal images (n=31) after LCC. The clinical factors of these two groups, including perinatal characteristics, clinical features during the LCC period, and neonatal morbidities, were compared. RESULTS: There were no significant differences in perinatal characteristics and postnatal morbidities between the two groups. Postnatal age was greater in the group with brain damage (16 days vs. 24 days, P=0.047). The lowest mean blood pressure (MBP) and lowest serum sodium concentration were significantly lower in the brain damage group (19 mm Hg vs. 22 mm Hg, P=0.034; 125 mmol/L vs. 129 mmol/L, P=0.043). There were no significant differences in other clinical factors, including cortisol levels, and inotrope and hydrocortisone use. In multivariate logistic regression, older postnatal age (odds ratio [OR], 1.147; P=0.049), lower MBP (OR, 0.616; P=0.031), and lower sodium concentration (OR, 0.728; P=0.037) during the LCC period highly predicted brain damage in infants with LCC (area under the curve 0.882, P=0.001). CONCLUSION: Close monitoring of LCC signs even in long-term stable preterm infants and management for preventing severe hyponatremia and hypotension are important to minimize the occurrence of brain damage in infants with LCC.

Diagnosis and Surveillance of Incidental Pancreatic Cystic Lesions: 2017 Consensus Recommendations of the Korean Society of Abdominal Radiology

The occurrence of incidentally detected pancreatic cystic lesions (PCLs) is continuously increasing. Radiologic examinations including computed tomography and magnetic resonance imaging with magnetic resonance cholangiopancreatography have been widely used as the main diagnostic and surveillance methods for patients with incidental PCLs. Although most incidentally detected PCLs are considered benign, they have the potential to become malignant. Currently, we have several guidelines for the management of incidental PCLs. However, there is still debate over proper management, in terms of accurate diagnosis, optimal follow-up interval, and imaging tools. Because imaging studies play a crucial role in the management of incidental PCLs, the 2017 consensus recommendations of the Korean Society of Abdominal Radiology for the diagnosis and surveillance of incidental PCLs approved 11 out of 16 recommendations. Although several challenges remain in terms of optimization and standardization, these consensus recommendations might serve as useful tools to provide a more standardized approach and to optimize care of patients with incidental PCLs.

High Acceleration Three-Dimensional T1-Weighted Dual Echo Dixon Hepatobiliary Phase Imaging Using Compressed Sensing-Sensitivity Encoding: Comparison of Image Quality and Solid Lesion Detectability with the Standard T1-Weighted Sequence

OBJECTIVE: To compare a high acceleration three-dimensional (3D) T1-weighted gradient-recalled-echo (GRE) sequence using the combined compressed sensing (CS)-sensitivity encoding (SENSE) method with a conventional 3D GRE sequence using SENSE, with respect to image quality and detectability of solid focal liver lesions (FLLs) in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced liver MRI. MATERIALS AND METHODS: A total of 217 patients with gadoxetic acid-enhanced liver MRI at 3T (54 in the preliminary study and 163 in the main study) were retrospectively included. In the main study, HBP imaging was done twice using the standard mDixon-3D-GRE technique with SENSE (acceleration factor [AF]: 2.8, standard mDixon-GRE) and the high acceleration mDixon-3D GRE technique using the combined CS-SENSE technique (CS-SENSE mDixon-GRE). Two abdominal radiologists assessed the two MRI data sets for image quality in consensus. Three other abdominal radiologists independently assessed the diagnostic performance of each data set and its ability to detect solid FLLs in 117 patients with 193 solid nodules and compared them using jackknife alternative free-response receiver operating characteristics (JAFROC). RESULTS: There was no significant difference in the overall image quality. CS-SENSE mDixon-GRE showed higher image noise, but lesser motion artifact levels compared with the standard mDixon-GRE (all p < 0.05). In terms of lesion detection, reader-averaged figures-of-merit estimated with JAFROC was 0.918 for standard mDixon-GRE, and 0.953 for CS-SENSE mDixon-GRE (p = 0.142). The non-inferiority of CS-SENSE mDixon-GRE over standard mDixon-GRE was confirmed (difference: 0.064 [−0.012, 0.081]). CONCLUSION: The CS-SENSE mDixon-GRE HBP sequence provided comparable overall image quality and non-inferior solid FFL detectability compared with the standard mDixon-GRE sequence, with reduced acquisition time.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration

OBJECTIVE: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. MATERIALS AND METHODS: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. RESULTS: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). CONCLUSION: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Trends in the Prevalence of Childhood Asthma in Seoul Metropolitan City, Korea: The Seoul Atopy ∙ Asthma-friendly School Project / 예방의학회지

OBJECTIVES: The project Seoul Atopy ∙ Asthma-friendly School investigated the current status of childhood asthma to enable formulation of a preventative policy. We evaluated the current prevalence of childhood asthma in Seoul and its trends and related factors. METHODS: The project was conducted annually from 2011 to 2016 and involved around 35 000 children aged 1-13 years. Based on the International Study of Asthma and Allergies in Childhood guidelines, the survey involved parents. The associations of the particulate matter (PM10) concentration, and the number of days on which the daily air quality guidance level was exceeded in the 25 districts of Seoul, with the prevalence of asthma were assessed. RESULTS: The age-standardized asthma prevalence in 2011 and 2016 was 6.74 and 4.02%, respectively. The prevalence of lifetime asthma treatment and treatment during the last 12 months tended to decrease from 2011 to 2016. Asthma treatment was significantly correlated with the number of days on which the daily air quality guidance level was exceeded, but not with the PM10 concentration. CONCLUSIONS: This study reports the prevalence of asthma among children in Seoul and confirmed the relationship between childhood asthma and known risk factors in a large-scale survey.