• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.240-252
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• 2023

Purpose To assess the effect of deep learning image reconstruction (DLIR) for head CT in pediatric patients. Materials and Methods We collected 126 pediatric head CT images, which were reconstructed using filtered back projection, iterative reconstruction using adaptive statistical iterative reconstruction (ASiR)-V, and all three levels of DLIR (TrueFidelity; GE Healthcare). Each image set group was divided into four subgroups according to the patients' ages. Clinical and dose-related data were reviewed. Quantitative parameters, including the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and qualitative parameters, including noise, gray matter-white matter (GM-WM) differentiation, sharpness, artifact, acceptability, and unfamiliar texture change were evaluated and compared. Results The SNR and CNR of each level in each age group increased among strength levels of DLIR. High-level DLIR showed a significantly improved SNR and CNR (p < 0.05). Sequential reduction of noise, improvement of GM-WM differentiation, and improvement of sharpness was noted among strength levels of DLIR. Those of high-level DLIR showed a similar value as that with ASiR-V. Artifact and acceptability did not show a significant difference among the adapted levels of DLIR. Conclusion Adaptation of high-level DLIR for the pediatric head CT can significantly reduce image noise. Modification is needed while processing artifacts.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.725-734
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• 2021

Objective: To intraindividually compare hepatocellular carcinoma (HCC) washout between MRIs using hepatobiliary agent (HBA) and extracellular agent (ECA). Materials and Methods: This study included 114 prospectively enrolled patients with chronic liver disease (mean age, 55 ± 9 years; 94 men) who underwent both HBA-MRI and ECA-MRI before surgical resection for HCC between November 2016 and May 2019. For 114 HCCs, the lesion-to-liver visual signal intensity ratio (SIR) using a 5-point scale (-2 to +2) was evaluated in each phase. Washout was defined as negative visual SIR with temporal reduction of visual SIR from the arterial phase. Illusional washout (IW) was defined as a visual SIR of 0 with an enhancing capsule. The frequency of washout and MRI sensitivity for HCC using LR-5 or its modifications were compared between HBA-MRI and ECA-MRI. Subgroup analysis was performed according to lesion size (< 20 mm or ≥ 20 mm). Results: The frequency of portal venous phase (PP) washout with HBA-MRI was comparable to that of delayed phase (DP) washout with ECA-MRI (77.2% [88/114] vs. 68.4% [78/114]; p = 0.134). The frequencies were also comparable when IW was allowed (79.8% [91/114] for HBA-MRI vs. 81.6% [93/114] for ECA-MRI; p = 0.845). The sensitivities for HCC of LR-5 (using PP or DP washout) were comparable between HBA-MRI and ECA-MRI (78.1% [89/114] vs. 73.7% [84/114]; p = 0.458). In HCCs < 20 mm, the sensitivity of LR-5 was higher on HBA-MRI than on ECA-MRI (70.8% [34/48] vs. 50.0% [24/48]; p = 0.034). The sensitivity was similar to each other if IW was added to LR-5 (72.9% [35/48] for HBA-MRI vs. 70.8% [34/48] for ECA-MRI; p > 0.999). Conclusion: Extracellular phase washout for HCC diagnosis was comparable between MRIs with both contrast agents, except for tumors < 20 mm. Adding IW could improve the sensitivity for HCC on ECA-MRI in tumors < 20 mm.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.29-38
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• 2006

After the first opening of the KTX in April 2004, travel time between major cities has been dramatically reduced. The reduction rates range from 32% to 47%. Considering travel time reduction between major cities, this study concerned about the intercity travel impact of the KTX operation. This study aimed to analyze intercity mode choice behavior of Daegu Citizens according to the first opening of the KTX. This study takes place in two sections. These are (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. This study estimated empirical models for analyzing intercity mode choice behavior according to the first opening of the KTX. This study makes use of the data from travel survey from Daegu metropolitan area. The main part of the survey was carried out in the KTX Dong-Daegu station. The survey data includes the information on travel from Daegu to Daejeon and from Daegu to Seoul. In order to analyze intercity choice behavior according to the frist opening of the KTX, multinomial model structure is used. For the model specification, a variety of behavioral assumptions about the factors which affect the mode choice, were considered. From the empirical model estimation, it is found that OVTT(Out-of-Vehicle Travel Time), OVTC(Out-of-Vehicle Travel Cost), IVTT(In-Vehicle Travel Time), IVTC(In-Vehicle Travel Cost), travel frequency, travel purpose, sex, age, occupation. household income, individual income are significant in choosing intercity travel mode. However, it is found that the intercity nde choice behavior is different between (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. Furthermore, some policy implications are discussed in conclusion.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.1
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• pp.28-35
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• 2008

Purpose: The aim of this study is to report the efficacy of infliximab, a monoclonal antibody directed against tumor necrosis factor alpha which is used for both treatment of refractory pediatric Crohn disease (CD) and induction of remission. Methods: Among pediatric patients who were diagnosed with CD at Samsung Medical Center between March 2001 and August 2007, a total of 16 patients were given infliximab to treat conventional therapyresistant refractory CD and severe active CD for induction of remission. Patients needing maintenance therapy were treated with an infliximab infusion every 8 weeks, and fistulizing CD patients occasionally received the infusion upon the condition that a fistula developed. The efficacy of treatment was assessed by comparing the Pediatric Crohn Disease Activity Index (PCDAI), Hct, ESR, CRP, and serum albumin levels using paired t-test. Results: The male/female ratio was 13:3, and the median age was 13 years (range, 21 months~15 years). The patients included 7 cases of therapy-resistant refractory CD, 7 cases of severe active CD, and 2 cases of fistulizing CD. Mean PCDAI before infliximab therapy was 34.19${\pm}$14.96, and mean follow-up PCDAI within 2 to 4 weeks after the last infusion was significantly lower, at 6.88${\pm}$10.31 (p=0.000). Hematological markers such as ESR (p=0.000), serum albumin (p=0.016), and CRP (p=0.009) also improved significantly after infusion. Remission was achieved in 2 of 4 patients refractory to conventional therapy. Among 3 steroid-dependent patients, 2 were able to discontinue steroid therapy, and dose reduction was possible in 1 patient. Remission after top-down therapy without prior use of other immunomodulators was achieved in 6 weeks in all 7 of the patients who had severe CD. Nine of ten refractory fistulizing CD patients also showed improvement after infliximab therapy. Conclusion: Infliximab was effective in pediatric refractory CD for induction of remission and maintenance therapy, as well as in severe CD for top-down induction therapy. Furthermore, infliximab has contributed to steroid cessation and dose reduction. Long-term follow-up evaluation is needed to determine safety and efficacy of infliximab in the future.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.225-238
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• 2007

In this study, the effects of dietary krill meal levels on cellular immunity in LPS-injected broiler chicks was evaluated. One day-old male broiler chicks(Ross) were fed on the experimental basal meal(0.0% krill meal), or diets containing 0.5%, 1.0% and 2.0% krill for 3 weeks, and the acute phase response was activated by intraperitoneally injection of Salmonella typhimurium lipopolysaccharide(LPS) 3 times at 9, 11, and 13 days of age. 1. Acute phase response induced a significant reduction in(p<0.05) daily weight gain and feed intake, and increases in liver and spleen weight. However, it was not affected by dietary krill meal levels. 2. The krill meal diets reduced TNF-α activity as compared to the basal diet after 24 hours (acute phase response) and 1 week(recovery from the acute phase response) following LPS injection (p<0.05). The acute phase response induced a significant increase(p<0.05) in TNF-α activity relative to the control in chicks fed on a basal diet, but this was also unaffected by dietary krill meal levels. 3. Acute phase response-mediated ovotransferrin levels(relative to what was measured in the control bird) were increased in birds fed on the basal, 1.0% and 2.0% krill diets, and were reduced in birds fed on the 0.5 % krill diet. 4. In LPS-injected chicks, 1.0% and 2.0% krill meal diets induced a significant reduction in(p<0.05) the Con A-induced proliferation of PBMC and splenocytes relative to what was observed in the chicks fed on a 0.5% krill diet, whereas the splenocytes proliferated in a linear fashion with the krill levels in the diets of the control birds. The results showed that the dietary levels of krill meal reduced TNF-α activity in the blood and also influenced blood ovotransferrin levels and the proliferation of PBMC and splenocytes, and krill meal is considered to be associated with both innate and cellular immunity in broiler chicks.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.378-394
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• 2016

Purpose: Screening of preschool-age children for nutrition programs to improve dietary intake and behaviors requires cost-effective and easily administered validated assessment tools. The purpose of this study was to develop a parent/caregiver-administered instrument for measuring diet quality and behaviors of preschoolers as a nutrition quotient for preschoolers (NQ-P). Methods: Development of NQ-P was carried out in three steps: item generation, item reduction, and validation. The 24-h dietary record was selected as the gold standard reference tool. The 38 items of the NQ-P checklist were derived from a systematic literature review, expert in-depth interviews, statistical analysis of the fifth Korean National Health and Nutrition Examination Survey data, and national nutrition policies and recommendations. Self-administered questionnaires were delivered to parents who recorded 24-h dietary intakes of 100 responders aged 3~5 yr. Pearson's correlation was used to measure the level of agreement between questionnaires. Item reduction was performed, and 20 items were selected based on survey results, expert reviews, and priorities of national nutrition policy and recommendations. The 412 nationwide subjects sampled through daycare centers completed the 20-item checklist questionnaire. The construct validity of the NQ-P was assessed using confirmatory factor analysis, LISREL. Results: After analyses of exploratory factors, NQ-P items identified three dimensions of diet (balance, moderation, and environment). The three-factor structure accounted for 49.28% of the total variance. Standardized path coefficients were used as weights of the items. The NQ-P and three-factor scores of the subjects were calculated by the obtained weights of the questionnaire items. Conclusion: A food behavior checklist for preschoolers' NQ would be a useful and suitable instrument for evaluating nutrition adequacy and dietary quality of Korean preschoolers.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.127-135
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• 2016

Purpose: The present study was aimed to investigate the effect of excessive near work by using a smartphone on subjective symptoms and accommodative and convergent function in their 40s. Methods: A total of 40 subjects(male, 10; female, 30; age, $43{\pm}7.2year$) in their 40s who have monocular and binocular visual acuities of 0.8 and 1.0, respectively, were divided into presbyopia group and non-presbyopia group. The subjects were asked to watch a movie on the screen of smartphone for 30 minutes. Their accommodative amplitude and facility, and relative accommodation were measured and compared before and after the use of smartphone. Changes in fusional vergence and near heterophoria by using smartphone were also evaluated. Furthermore, the change of subjective symptoms was surveyed using a questionnaire. Results: The presbyopia in mid-40s reported discomfort in an order of asthenopia, blur and dryness after the use of smartphone. Accommodative function and non-strabismic binocular function were generally decreased. Accommodative functions such as monocular accommodative amplitude, and relative accommodation were significantly decreased after smartphone use, and the change of phoria was observed as a result of decreased convergence and divergence. Negative fusional vergence was also significantly reduced. On the other hand, non-presbyopia in mid-40s reported discomfort in an order of asthenopia, dryness and blur, and only accommodative amplitude among the accommodative functions was significantly reduced. Significant reduction of negative fusional vergence was also observed. Conclusion: From the results, it was confirmed that the subjective discomfort of mid-40s after smarphone use might be related to whether presbyopia or not. It was due to not only the reduction of accommodative function but also the overall deterioration of visual function including heterophoria and fusional vergence. Therefore, it suggests that the accurate determination of the cause based on the overall visual functional tests such as heterophoria, fusional vergence as well as the decrease of accommodation due to the aging may be necessary when the mid-40s feels discomfortable symptoms by near work.

• Journal of Gastric Cancer
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• v.4 no.3
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• pp.156-163
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• 2004

Purpose: While E-cadherin in normal cells induces calciumdependent cell-cell adhesion, in malignant cell, it plays a role in invasion and metastasis with a reduction of adhesion. Serum soluble E-cadherin is a result of the reduction of the cellular E-cadherin molecule and is found in the circulation of normal individuals, but it is particularly known to be increased in patients with malignancies. Accordingly, through checking the level of serum soluble E-cadherin in patients with gastric cancer and analyzing it in the view of clinicopathology, we investigated whether serum soluble E-cadherin could be translated into a clinicopathologic esult and used as a tumor marker. Materials and Methods: The investigation targeted 88 patients who had been diagnosed as having gastric cancer by the Department of Surgery, St. Mary's Hospital, from October 1, 2002, to July 30, 2003, and who had under gone performed surgery. We measured the level of preoperative serum E-cadherin in the 88 patients by unsing ELISA. Among them, we collected gastric cancer tissues from 54 patients and executed immunohistochemistry for E-cadherin. The samples were compared with normal tissues in terms of both serum E-cadherin level and immunohistochemistry level, as well as with other clinicopathologic factors. Result: The mean serum E-cadherin level of the 88 patients was 4368.7 ng/ml and was significantly higher than the level in 12 normal control patients, 3335.5 ng/ml (P=0.016). In terms of clinicopathology, the serum level of E-cadherin was significantly correlated with increasing age (P=0.0006) and was higher in positive venous invasion patients (P=0.0005). When the E-cadherin immunohistochemical stain was compared with the serum E-cadherin level in 54 patients, no significant statistically meaningful result was obtained (P=0.2881). However, 4 patients with serum E-cadherin levels about 6000 ng/ml were classified into the lower expression group ($<80\%$ of E-cadherin immunohistochemicals stain. In the analysis for 36 patients who were early gastric cancer patients, the serum E-cadherin level in lymph-node-metastatic patients was higher than it was in the other patients (P=0.0442). Conclusion: The serum E-cadherin level in gastric cancer patients was higher than the level in normal control patients. In advanced gastric cancer patients, that the difference was increased. Also, since the E-cadherin level correlated with the serum E-cadherin level with venous invasion, it can be used as an effective tumor marker for gastric cancer. Particularly, in that the serum E-cadherin level correlated with lymph node metastasis in early gastic cancer, it can be used when a therapeutic method for early gastric cancer is selected.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.2
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• pp.160-168
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• 2000

Purpose: The purpose of this study was to evaluate the clinical and abdominal ultrasonogra- phic(US) features of spontaneously reduced transient small bowel intussusception in chlidren. Methods: We retrospectively reviewed the clinical and US findings of 98 children with intussusception who were admitted to the Pediatric Department of Ulsan Dong-Kang General Hospital from Mar. 1999 to Feb. 2000. Results: 1) Among 98 cases, there were 12 cases (12.3%) of transient small bowel intussusception(TSBI) and 86 cases (87.7%) of classic intussusception (CI). 2) The peak incidence of age in TSBI was over 3 years, which was older than that in CI. With regard to sex distribution, male predominated in both type. 3) Clinical symptoms and signs including cyclic irritability, vomiting, bloody stool, and abdominal mass in TSBI group were less common than those in CI group (41.7%, 33.4%, 0.0%, 0.0% vs 91.9%, 59.3%, 41.9%, 26.7%, respectively) but persistent abdominal pain was more common in TSBI group than in CI group (58.5% vs 11.2%). 4) The size of total target sign and surrounding peripheral hypoechoic rim of TSBI group on US were smaller than those of CI group ($11.95{\pm}2.61$ mm, $2.08{\pm}1.15$ mm vs $26.91{\pm}5.98$ mm, $7.86{\pm}2.77$ mm, respectively). 5) Concomittant illness was found more frequently in TSBI group than in CI group (66.7% vs 26.7%). 6) All case of TSBI group were reduced spontaneouly, which were confirmed by US, but none of CI group. Conclusion: Transient small bowel intussusception is probably more common than generally thought and its clinical and US findings is quite different from classical obstructing intussus-ception. Because all of our cases resulted in spontaneous reduction, we recommend careful observation and repeat examination rather than an immediate operation in transient small bowel intussusception.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.30-35
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• 2013

Purpose: One of the current services, providing information to the patients and their guardians by using promotion materials induces positive responses and contributes to the improvement of the hospital reliability. Therefore, the objective of this study is to evaluate the effectiveness of audio visual materials, one of the means of promotion, as a way to give accurate medical information to resolve patient's curiosity about purpose and procedure of their examination and deplete complains about waiting which attributes negative effect to service quality assessment. Materials and Methods: 60 patients(mean age $53.97{\pm}12.24$, male : female = 26 : 34) who had $^{18}F-FDG PET/CT$ scan from July 2012 to August 2012 in Seoul Asan Medical Center were referred to the study. All of the patients having PET/CT scan were asked to watch an informative video material before the injection of radiopharmaceutical ($^{18}F-FDG$) and to fill in a questionnaire. Results: As a result of analyzing the contents of questionnaire, 52% of 60 patients had PET/CT scan for the first time and 72.4% of the patients read the PET/CT guidebook offered from their outpatient department or inpatient wards before their scan. After we searched the level of previous knowledge of the purpose and method of PET/CT scan, the patients answered 25.1% "know well", 34% "not sure", 40.9% "don't know" respectively. And 84.7% of the patients answered that watching the PET/CT guide video before the injection helps understanding what exam they were having and 15.3% of the patients did not. For the question asking ever the patients have experienced using our homepage or smart phone QR code to see the guide video before they visit out PET center, only 3.3% of them answered "yes". Lastly, the patients answered 60.1% "yes", 31.4% "so so" and 8.5% "no" respectively for the question asking whether watching the video makes the patients to fill the waiting time short. Conclusion: It is found that understanding of objective and method of the PET/CT scan and level of satisfaction was improved after the patients watched the guide video whether they had PET/CT scan before and read the PET/CT guidebook or not. Also, watching the video was effective for the reduction of perceptible waiting time. But while displaying the PET/CT guide video is useful for providing information about the scan and shortening the waiting time as one of the medical service, utilization of service was actually very poor because of the passive promotion and indifference of the patients about their examination. Therefore, from now on, it is necessary to construct the healthcare system which can be offered to more patients through the active promotion.